feat(更新依赖): 更新guigo、gmsm

.gitea/workflows/build.sh

@@ -1,5 +1,6 @@
 #!/bin/bash
 set -e
 export TZ=Asia/Shanghai
-GOOS=js GOARCH=wasm CGO_ENABLED=0 go build -o assets/webui/ofdgo.wasm -trimpath -ldflags "-s -w -buildid=" ./cmd/webui/wasm.go
-GOOS=linux GOARCH=amd64 CGO_ENABLED=0 go build -o main -trimpath -ldflags "-s -w -buildid=" ./cmd/webui/webui.go
+export Version="$(git show -s --format='%ct-%H' HEAD)"
+GOOS=js GOARCH=wasm CGO_ENABLED=0 go build -o assets/webui/wasm/ofdgo.wasm -trimpath -ldflags "-s -w -buildid=" ./cmd/webui/wasm.go
+GOOS=linux GOARCH=amd64 CGO_ENABLED=0 go build -o main -trimpath -ldflags "-s -w -buildid= -X github.com/xiaoqidun/ofdgo/internal/build.Version=$Version" ./cmd/webui/webui.go

.gitignore

@@ -1,8 +1,9 @@
 .idea/
 .vscode/
 .devcontainer/
+releases/
 go.work
 go.work.sum
-assets/webui/ofdgo.wasm
 *.exe
 *.exe~
+assets/webui/wasm/ofdgo.wasm

Dockerfile

@@ -1,5 +1,5 @@
 # 基础镜像
-FROM alpine:3.24.2
+FROM alpine:3.24.3
 
 # 作者信息
 LABEL authors="肖其顿 (XIAO QI DUN)"

README.md

@@ -3,14 +3,28 @@
 
 # 主要能力
 - 文档处理：创建、读写、拆分、合并、压缩
-- 渲染转换：导入、导出、矢量、位图、批量
-- 文档安全：加密、解密、签名、签章、验签
+- 文档阅读：搜索、缩放、旋转、双页、连续
+- 文档管理：新建、导入、切换、排序、删除
+- 版本管理：创建、改名、切换、另存、删除
 - 页面管理：添加、导入、复制、排序、删除
-- 文字处理：插入、编辑、排版、搜索、提取
+- 文档编辑：选区、重排、事务、撤销、重做
+- 文字处理：插入、编辑、替换、排版、提取
+- 文字样式：混排、粗体、斜体、阴影、底色
+- 字体处理：匹配、内嵌、外置、子集、提取
 - 图片处理：插入、替换、缩放、裁剪、提取
-- 图形处理：绘制、组合、变换、对齐、分布
-- 注解管理：批注、高亮、链接、水印、印章
-- 资源管理：字体、色彩、图片、媒体、附件
+- 图形处理：绘制、变换、组合、对齐、分布
+- 色彩管理：调色、渐变、图案、透明、转换
+- 文档结构：图层、模板、目录、书签、标引
+- 资源管理：导入、绑定、替换、提取、清理
+- 注解管理：批注、高亮、水印、印章、链接
+- 交互动作：跳转、链接、附件、音频、视频
+- 电子发票：提取、创建、编辑、校验、同步
+- 文档安全：签名、签章、验签、加密、解密
+- 三维处理：解析、材质、纹理、动画、渲染
+- 页面渲染：矢量、位图、裁剪、蒙版、合成
+- 批量转换：选页、并行、进度、取消、打包
+- 打印输出：预览、双面、合印、小册、海报
+- 应用交互：标签、链接、关联、拖放、复用
 
 # 在线使用
 [OFDGo WebUI](https://ofdgo.aite.me/)，将OFDGo编译为WASM提供服务
@@ -44,13 +58,35 @@ docker run -d -p 80:80 ccr.ccs.tencentyun.com/xiaoqidun/ofdgo:latest
 :: 1. 编译OFDGo WASM
 set GOOS=js
 set GOARCH=wasm
-go build -o assets/webui/ofdgo.wasm -trimpath -ldflags "-s -w -buildid=" ./cmd/webui/wasm.go
+go build -o assets/webui/wasm/ofdgo.wasm -trimpath -ldflags "-s -w -buildid=" ./cmd/webui/wasm.go
 :: 2. 编译OFDGo WebUI
 set GOOS=windows
 set GOARCH=amd64
 go build -o ofdgo_webui.exe -trimpath -ldflags "-s -w -buildid=" ./cmd/webui/webui.go
 ```
 
+# 原生桌面
+基于 [GUIGo](https://github.com/xiaoqidun/guigo) 实现，运行前需参照其说明安装系统依赖
+
+```batch
+set CGO_ENABLED=0
+
+:: 构建Linux arm64（aarch64）
+set GOOS=linux
+set GOARCH=arm64
+go build -o ofdgo_linux_arm64 -trimpath -ldflags "-s -w -buildid=" ./cmd/webview
+
+:: 构建Linux amd64（x64/x86_64）
+set GOOS=linux
+set GOARCH=amd64
+go build -o ofdgo_linux_amd64 -trimpath -ldflags "-s -w -buildid=" ./cmd/webview
+
+:: 构建Windows amd64（x64/x86_64）
+set GOOS=windows
+set GOARCH=amd64
+go build -o ofdgo_windows_amd64.exe -trimpath -ldflags "-H windowsgui -s -w -buildid=" ./cmd/webview
+```
+
 # 安装引擎
 ```shell
 go get -u github.com/xiaoqidun/ofdgo
@@ -61,6 +97,7 @@ go get -u github.com/xiaoqidun/ofdgo
 package main
 
 import (
+	"context"
 	"log"
 	"os"
 
@@ -89,12 +126,11 @@ func main() {
 		log.Fatal(err)
 	}
 	// 3. 保存文档
-	ofdFile, err := os.Create("test.ofd")
+	output, err := ofdgo.NewFileOutput("test.ofd")
 	if err != nil {
 		log.Fatal(err)
 	}
-	defer ofdFile.Close()
-	if _, err := editor.WriteTo(ofdFile); err != nil {
+	if _, err := editor.SaveAs(context.Background(), output, ofdgo.WriteOptions{}); err != nil {
 		log.Fatal(err)
 	}
 }
@@ -105,15 +141,20 @@ func main() {
 package main
 
 import (
+	"context"
 	"log"
-	"os"
 
 	"github.com/xiaoqidun/ofdgo"
 )
 
 func main() {
 	// 1. 打开文档
-	reader, err := ofdgo.Open("test.ofd")
+	input, err := ofdgo.OpenFile(context.Background(), "test.ofd", ofdgo.InputOptions{})
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer input.Close()
+	reader, err := ofdgo.NewReader(input)
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -125,12 +166,11 @@ func main() {
 	}
 	editor.Info.Title = "编辑后的"
 	// 3. 另存文档
-	ofdFile, err := os.Create("edited.ofd")
+	output, err := ofdgo.NewFileOutput("edited.ofd")
 	if err != nil {
 		log.Fatal(err)
 	}
-	defer ofdFile.Close()
-	if _, err := editor.WriteTo(ofdFile); err != nil {
+	if _, err := editor.SaveAs(context.Background(), output, ofdgo.WriteOptions{}); err != nil {
 		log.Fatal(err)
 	}
 }
@@ -150,15 +190,11 @@ import (
 
 func main() {
 	// 1. 打开文档
-	pdfFile, err := os.Open("test.pdf")
-	if err != nil {
-		log.Fatal(err)
-	}
-	defer pdfFile.Close()
-	info, err := pdfFile.Stat()
+	input, err := ofdgo.OpenFile(context.Background(), "test.pdf", ofdgo.InputOptions{})
 	if err != nil {
 		log.Fatal(err)
 	}
+	defer input.Close()
 	// 2. 创建文件
 	ofdFile, err := os.Create("test.ofd")
 	if err != nil {
@@ -166,7 +202,7 @@ func main() {
 	}
 	defer ofdFile.Close()
 	// 3. 转换文档
-	report, err := ofdgo.ConvertPDF(context.Background(), pdfFile, info.Size(), ofdFile, ofdgo.PDFImportOptions{})
+	report, err := ofdgo.ConvertPDF(context.Background(), input, ofdFile, ofdgo.PDFImportOptions{})
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -182,6 +218,7 @@ func main() {
 package main
 
 import (
+	"context"
 	"log"
 	"os"
 
@@ -190,7 +227,12 @@ import (
 
 func main() {
 	// 1. 打开OFD文件
-	reader, err := ofdgo.Open("test.ofd")
+	input, err := ofdgo.OpenFile(context.Background(), "test.ofd", ofdgo.InputOptions{})
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer input.Close()
+	reader, err := ofdgo.NewReader(input)
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -214,6 +256,7 @@ func main() {
 package main
 
 import (
+	"context"
 	"log"
 	"os"
 
@@ -222,12 +265,13 @@ import (
 
 func main() {
 	// 1. 打开OFD文件
-	data, err := os.ReadFile("test.ofd")
+	input, err := ofdgo.OpenFile(context.Background(), "test.ofd", ofdgo.InputOptions{})
 	if err != nil {
 		log.Fatal(err)
 	}
+	defer input.Close()
 	// 2. 验证OFD签名
-	reports, err := ofdgo.VerifySignaturesBytes(data)
+	reports, err := ofdgo.VerifySignatures(input)
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -255,5 +299,44 @@ func main() {
 }
 ```
 
+# 提取发票
+```go
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"log"
+	"os"
+
+	"github.com/xiaoqidun/ofdgo"
+)
+
+func main() {
+	// 1. 打开OFD文件
+	input, err := ofdgo.OpenFile(context.Background(), "invoice.ofd", ofdgo.InputOptions{})
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer input.Close()
+	reader, err := ofdgo.NewReader(input)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer reader.Close()
+	// 2. 提取发票信息
+	report, err := reader.Invoices()
+	if err != nil {
+		log.Fatal(err)
+	}
+	// 3. 输出提取结果
+	encoder := json.NewEncoder(os.Stdout)
+	encoder.SetIndent("", "  ")
+	if err := encoder.Encode(report); err != nil {
+		log.Fatal(err)
+	}
+}
+```
+
 # 授权协议
 本项目使用 [Apache License 2.0](https://github.com/xiaoqidun/ofdgo/blob/main/LICENSE) 授权协议

assets/webui/assets.go

@@ -14,25 +14,14 @@
 
 package webuiassets
 
-import (
-	"crypto/sha256"
-	"embed"
-	"encoding/hex"
-)
+import "embed"
 
 // FS WebUI嵌入静态文件
 //
-//go:embed index.html ofdgo.css ofdgo.js ofdgo.json ofdgo.svg ofdgo.wasm ofdgo_edit.js ofdgo_font.js ofdgo_wasm.js ofdgo_work.js wasm_exec.js
+//go:embed index.html ofdgo.css ofdgo.ico ofdgo.js ofdgo.json ofdgo.png ofdgo.svg ofdgo_edit.js ofdgo_font.js ofdgo_host.js ofdgo_print.js ofdgo_theme.js ofdgo_util.js ofdgo_view.js ofdgo_wasm.js ofdgo_work.js wasm_exec.js
 var FS embed.FS
 
-// Checksum 计算WebUI嵌入资源校验值
-// 返回: string SHA-256十六进制校验值
-func Checksum() string {
-	hash := sha256.New()
-	entries, _ := FS.ReadDir(".")
-	for _, entry := range entries {
-		data, _ := FS.ReadFile(entry.Name())
-		hash.Write(data)
-	}
-	return hex.EncodeToString(hash.Sum(nil))
-}
+// NativeFS WebView嵌入静态文件
+//
+//go:embed index.html ofdgo.css ofdgo.ico ofdgo.js ofdgo.json ofdgo.png ofdgo.svg ofdgo_edit.js ofdgo_font.js ofdgo_host.js ofdgo_print.js ofdgo_theme.js ofdgo_util.js ofdgo_view.js
+var NativeFS embed.FS

assets/webui/ofdgo.json

@@ -22,6 +22,12 @@
 			"src": "./ofdgo.svg",
 			"sizes": "any",
 			"type": "image/svg+xml"
+		},
+		{
+			"src": "./ofdgo.png",
+			"sizes": "512x512",
+			"type": "image/png",
+			"purpose": "any"
 		}
 	]
 }

assets/webui/ofdgo_font.js

@@ -1,39 +1,59 @@
+import { bindDropdownPointer, positionDropdown } from "./ofdgo_util.js";
+
 const DATABASE = "ofdgo";
 
 export class FontPicker {
-	constructor(input, toggle, list, onChange, onOpen) {
-		Object.assign(this, { input, toggle, list, onChange, onOpen, fonts: [], value: "", active: -1, open: false });
+	constructor(input, toggle, list, onChange, onOpen, groupFonts) {
+		Object.assign(this, { input, toggle, list, onChange, onOpen, groupFonts, fonts: [], groups: [], value: "", active: -1, open: false });
 		input.addEventListener("input", () => this.show(input.value));
 		input.addEventListener("focus", () => input.select());
-		input.addEventListener("click", () => { if (!this.open) this.show(); });
+		input.addEventListener("pointerdown", event => { if (event.button === 0 && !this.open) event.preventDefault(); });
+		input.addEventListener("click", () => { if (!this.open) { input.focus(); input.select(); this.show(); } });
 		input.addEventListener("keydown", event => this.keyDown(event));
 		input.addEventListener("blur", () => { this.commitExact(); this.close(); });
 		toggle.addEventListener("pointerdown", event => event.preventDefault());
 		toggle.addEventListener("click", () => {
 			if (this.open) this.close();
-			else { input.focus(); this.show(); }
-		});
-		list.addEventListener("pointerdown", event => {
-			if (event.target.closest("[role=option]")) event.preventDefault();
-		});
-		list.addEventListener("click", event => {
-			const option = event.target.closest("[role=option]");
-			if (option) this.choose(Number(option.dataset.index));
+			else { input.focus(); input.select(); this.show(); }
 		});
+		bindDropdownPointer(list, index => this.choose(index));
 		window.addEventListener("resize", () => this.close());
 	}
 
-	setFonts(fonts, selected) {
-		this.close();
+	setFonts(fonts, selected, preserve = false) {
+		const open = preserve && this.open;
+		if (!open) this.close();
 		this.fonts = fonts;
+		this.groups = fonts.map((_, index) => [index]);
 		this.names = new Map();
 		for (const font of fonts) {
-			const name = (font.fullName || font.name).normalize("NFKC").toLocaleLowerCase();
+			const name = (font.menuFamily || font.fullName || font.name).normalize("NFKC").toLocaleLowerCase();
 			this.names.set(name, (this.names.get(name) || 0) + 1);
 		}
-		const key = font => font?.id || font?.postscriptName;
+		const key = font => font?.richKey || font?.id || font?.postscriptName;
 		this.value = !fonts.length ? "" : selected === null ? "-1" : String(Math.max(0, fonts.findIndex(font => key(font) === key(selected))));
-		this.restore();
+		if (open) {
+			const active = this.matches[this.active]?.font;
+			this.show(this.query, false);
+			const index = active ? this.matches.findIndex(({ font }) => !font.disabled && key(font) === key(active)) : -1;
+			if (index >= 0) this.activate(index);
+		} else this.restore();
+		if (this.groupFonts) this.grouping = this.groupFonts(fonts).then(groups => {
+			if (this.fonts !== fonts) return;
+			this.groups = groups;
+			this.names.clear();
+			for (const group of groups) {
+				const font = fonts[group[0]], name = (font.menuFamily || font.fullName || font.name).normalize("NFKC").toLocaleLowerCase();
+				this.names.set(name, (this.names.get(name) || 0) + 1);
+			}
+			if (this.open) {
+				const active = this.matches[this.active]?.index;
+				this.show(this.query, false);
+				const index = this.matches.findIndex(({ group, font }) => group.includes(active) && !font.disabled);
+				if (index >= 0) this.activate(index);
+			}
+			else this.restore();
+		}).catch(() => {});
 	}
 
 	setDisabled(disabled) {
@@ -43,36 +63,45 @@ export class FontPicker {
 
 	restore() {
 		const font = this.fonts[Number(this.value)];
-		this.input.value = font?.fullName || font?.name || "";
+		const value = font?.menuFamily || font?.fullName || font?.name || "";
+		if (this.input.value !== value) {
+			this.input.value = value;
+			if (document.activeElement === this.input) this.input.select();
+		}
 		this.input.scrollLeft = 0;
 		this.input.title = font ? [this.input.value, this.sourceLabel(font)].filter(Boolean).join(" · ") : "";
-		this.input.setAttribute("aria-expanded", String(this.open));
-		this.input.removeAttribute("aria-activedescendant");
 	}
 
 	sourceLabel(font) {
-		const name = (font.fullName || font.name).normalize("NFKC").toLocaleLowerCase();
+		const name = (font.menuFamily || font.fullName || font.name).normalize("NFKC").toLocaleLowerCase();
 		if (this.names.get(name) < 2) return "";
 		return font.embedded ? "内嵌" : font.file || ["stored", "upload"].includes(font.source) ? "上传" : "系统";
 	}
 
 	show(query = "", load = true) {
 		if (this.input.disabled) return;
+		this.query = query;
 		const normalize = value => value.normalize("NFKC").toLocaleLowerCase().replace(/\s+/g, " ").trim();
 		const terms = normalize(query).split(" ").filter(Boolean);
-		this.matches = this.fonts.map((font, index) => ({ font, index })).filter(({ font }) => {
-			const name = normalize([font.fullName, font.name, font.family, font.style, font.postscriptName, ...(font.names || [])].filter(Boolean).join(" "));
+		this.matches = this.groups.map(group => {
+			const index = group.find(index => !this.fonts[index].bold && !this.fonts[index].italic && !this.fonts[index].disabled) ?? group[0];
+			return { font: this.fonts[index], index, group };
+		}).filter(({ group }) => {
+			const name = normalize(group.flatMap(index => {
+				const font = this.fonts[index];
+				return [font.menuFamily, font.menuStyle, font.fullName, font.name, font.family, font.style, font.postscriptName, ...(font.names || [])];
+			}).filter(Boolean).join(" "));
 			return terms.every(term => name.includes(term));
 		});
 		this.list.replaceChildren();
 		for (const { font, index } of this.matches) {
 			const option = document.createElement("div");
+			option.className = "font-option";
 			option.id = `${this.list.id}-${index}`;
 			option.dataset.index = String(index);
-			option.setAttribute("role", "option");
-			option.setAttribute("aria-disabled", String(Boolean(font.disabled)));
+			option.setAttribute("data-disabled", String(Boolean(font.disabled)));
 			const name = document.createElement("span");
-			name.textContent = font.fullName || font.name;
+			name.textContent = font.menuFamily || font.fullName || font.name;
 			option.append(name);
 			const source = this.sourceLabel(font);
 			if (source) {
@@ -92,30 +121,24 @@ export class FontPicker {
 		}
 		if (!this.open) this.list.showPopover();
 		this.open = true;
-		this.input.setAttribute("aria-expanded", "true");
 		this.position();
-		const selected = this.matches.findIndex(({ font, index }) => !font.disabled && String(index) === this.value);
+		const selected = this.matches.findIndex(({ font, group }) => !font.disabled && group.includes(Number(this.value)));
 		this.activate(selected < 0 ? this.matches.findIndex(({ font }) => !font.disabled) : selected);
 		if (load) this.onOpen?.();
 	}
 
 	position() {
 		if (!this.open) return;
-		const rect = this.input.parentElement.getBoundingClientRect();
-		if (rect.right <= 0 || rect.left >= window.innerWidth) { this.close(); return; }
-		const width = Math.min(rect.width, window.innerWidth - 16);
-		Object.assign(this.list.style, { left: `${Math.max(8, Math.min(rect.left, window.innerWidth - width - 8))}px`,
-			top: `${rect.bottom + 4}px`, width: `${width}px`, maxHeight: `${Math.max(40, Math.min(280, window.innerHeight - rect.bottom - 12))}px` });
+		if (!positionDropdown(this.list, this.input.parentElement)) this.close();
 	}
 
 	activate(index) {
 		this.active = index;
-		[...this.list.children].forEach((option, i) => option.setAttribute("aria-selected", String(i === index)));
+		[...this.list.children].forEach((option, i) => option.setAttribute("data-selected", String(i === index)));
 		const option = this.list.children[index];
 		if (option) {
-			this.input.setAttribute("aria-activedescendant", option.id);
 			option.scrollIntoView({ block: "nearest" });
-		} else this.input.removeAttribute("aria-activedescendant");
+		}
 	}
 
 	choose(index) {
@@ -123,16 +146,27 @@ export class FontPicker {
 		const changed = this.value !== String(index);
 		this.value = String(index);
 		this.close();
-		if (changed) return this.onChange();
+		if (changed) {
+			const task = this.changing = Promise.resolve(this.onChange());
+			return task.finally(() => { if (this.changing === task) this.changing = null; });
+		}
 	}
 
 	commitExact() {
 		const value = this.input.value.trim().toLocaleLowerCase();
 		const matches = font => font && !font.disabled
-			&& [font.fullName, font.name, font.postscriptName, ...(font.names || [])].some(name => name?.toLocaleLowerCase() === value);
+			&& [font.menuFamily, font.fullName, font.name, font.postscriptName, ...(font.names || [])].some(name => name?.toLocaleLowerCase() === value);
 		const selected = Number(this.value);
 		const index = matches(this.fonts[selected]) ? selected : this.fonts.findIndex(matches);
-		if (index >= 0) this.choose(index);
+		if (index >= 0) return this.choose(index);
+	}
+
+	prepareCommit(event) {
+		if (this.open && (!event || ![this.input, this.toggle, this.list].some(node => node.contains(event.target)))) {
+			this.commitExact();
+			this.close();
+		}
+		return this.changing;
 	}
 
 	close() {
@@ -141,7 +175,7 @@ export class FontPicker {
 	}
 
 	keyDown(event) {
-		if (event.isComposing) return;
+		if (event.isComposing || event.key === "Tab" && (event.ctrlKey || event.metaKey || event.altKey)) return;
 		if (!["Escape", "Enter", "ArrowDown", "ArrowUp", "Tab"].includes(event.key)) return;
 		event.stopPropagation();
 		if (event.key === "Escape") {
@@ -163,7 +197,8 @@ export class FontPicker {
 }
 
 export class FontManager {
-	constructor({ onChange, onPermissionChange }) {
+	constructor({ onChange, onPermissionChange, host = null }) {
+		this.host = host;
 		this.userFonts = [];
 		this.localFonts = [];
 		this.catalog = [];
@@ -271,7 +306,7 @@ export class FontManager {
 
 	async queryLocal() {
 		try {
-			const available = await window.queryLocalFonts();
+			const available = this.host ? await this.host.fonts() : await window.queryLocalFonts();
 			this.catalog = available;
 			this.catalogLoaded = true;
 			this.permission = "granted";
@@ -298,6 +333,7 @@ export class FontManager {
 	}
 
 	async read(font) {
+		if (font.nativeFile) return font.nativeFile;
 		if (font.blob) {
 			const blob = await font.blob();
 			return new Uint8Array(await blob.arrayBuffer());
@@ -316,13 +352,44 @@ export class FontManager {
 		}), ...this.catalog];
 	}
 
-	async loadFaces(inspect) {
-		while (true) {
+	async loadFaces(inspect, current = () => true) {
+		while (current()) {
 			const file = this.userFonts.find(font => font.enabled && !font.faces);
-			if (!file) return;
+			if (!file) break;
 			try { file.faces = await inspect(await this.read(file)); }
-			catch { file.faces = []; }
+			catch { if (!current()) return; file.faces = []; }
 		}
+		const pending = this.catalog.filter(font => font.blob && !font.menuFamily && !font.metadataFailed);
+		await Promise.all(Array.from({ length: Math.min(4, pending.length) }, async () => {
+			while (current() && pending.length) {
+				const font = pending.shift();
+				try {
+					const faces = await inspect(await this.read(font));
+					const face = faces.find(face => face.postscriptName === font.postscriptName);
+					if (face) Object.assign(font, { index: face.index, menuFamily: face.menuFamily, menuStyle: face.menuStyle, familyKey: face.familyKey, bold: face.bold, italic: face.italic, names: face.names });
+					else font.metadataFailed = true;
+				} catch { if (current()) font.metadataFailed = true; }
+			}
+		}));
+	}
+
+	async defaultFont(order, inspect, current = () => true) {
+		const fonts = this.editorFonts().filter(font => !font.disabled);
+		if (!fonts.length) return;
+		const families = [["DengXian", "等线"], ["Microsoft YaHei", "微软雅黑"], ["PingFang SC", "苹方-简", "苹方 简体"],
+			["Noto Sans SC", "Noto Sans CJK SC"], ["Source Han Sans SC", "Source Han Sans CN", "思源黑体", "思源黑体 CN"]];
+		const indices = await order(fonts, families);
+		let fallback = fonts.length;
+		for (const index of indices) {
+			if (!current()) return;
+			try {
+				await inspect(fonts[index], "中文汉字编辑水印，。！？");
+				if (current()) return fonts[index];
+			} catch (error) {
+				if (error.missingGlyphs) fallback = Math.min(fallback, index);
+			}
+		}
+		if (current()) return fonts[fallback];
 	}
 
 	async add(fonts) {
@@ -402,7 +469,7 @@ export class FontManager {
 		for (const font of fonts) {
 			if (disabled.has(this.localName(font))) continue;
 			const names = [this.localName(font), font.postscriptName && `${font.postscriptName}.ttf`,
-				font.family && `${[font.family, font.style].filter(Boolean).join(" ")}.ttf`];
+				font.family && `${[font.family, font.style].filter(Boolean).join(" ")}.ttf`, ...(font.names || []).map(name => `${name}.ttf`)];
 			for (const name of names) {
 				if (name && !entries.has(name)) entries.set(name, font);
 			}
@@ -411,10 +478,15 @@ export class FontManager {
 	}
 
 	canReadLocal() {
-		return typeof window.queryLocalFonts === "function";
+		return !!this.host || typeof window.queryLocalFonts === "function";
 	}
 
 	async refreshPermission() {
+		if (this.host) {
+			this.permission = "granted";
+			this.onPermissionChange();
+			return;
+		}
 		if (!this.canReadLocal() || !navigator.permissions?.query) {
 			this.onPermissionChange();
 			return;

assets/webui/ofdgo_host.js

@@ -0,0 +1,845 @@
+let engineModule = null;
+let engineScheduler = null;
+let engineSequence = 0;
+const engineRuntimes = new Map();
+
+function requestKey(worker, data) {
+	return worker.shared ? JSON.stringify([data.engineID, data.id]) : data.id;
+}
+
+export function engineLimits() {
+	engineScheduler ||= new BrowserScheduler();
+	return {parallelism: engineScheduler.capacity, memoryBytes: engineScheduler.budget};
+}
+
+class BrowserScheduler {
+	constructor() {
+		this.budget = Math.max(256, Math.min(2048, (navigator.deviceMemory || 2) * 256)) * 1024 * 1024;
+		this.capacity = Math.max(1, Math.min((navigator.hardwareConcurrency || 2) - 1, Math.floor(this.budget / (128 << 20))));
+		this.limit = Math.min(this.capacity, Math.max(1, Math.floor(this.budget / (512 << 20))));
+		this.workers = new Set();
+		this.queue = [];
+		this.sequence = 0;
+	}
+
+	get memory() {
+		return [...this.workers].reduce((total, worker) => total + Math.max(worker.memory, worker.reservation), 0);
+	}
+
+	active() {
+		return [...this.workers].reduce((total, worker) => total + new Set([...worker.operations.values()].map(data => data.engineID)).size, 0);
+	}
+
+	owner(worker, data) {
+		return worker.shared ? worker.sessions.get(data.engineID) : worker;
+	}
+
+	priority(task) {
+		return Number(task.worker.batch || this.owner(task.worker, task.data)?.foreground === false) + Number(!!task.data.preload || !!task.data.background);
+	}
+
+	submit(worker, data, transfer) {
+		if (data.preload && this.owner(worker, data)?.pagesPaused) {
+			worker.receive({data:{engineID:data.engineID, id:data.id, ok:false, canceled:true, error:"预加载已暂停"}});
+			return;
+		}
+		this.queue.push({worker, data, transfer, queued:performance.now(), order:++this.sequence});
+		this.drain();
+	}
+
+	send(task) {
+		const {worker, data, transfer} = task;
+		worker.requests.set(requestKey(worker, data), performance.now());
+		worker.operations.set(requestKey(worker, data), data);
+		try { worker.worker.postMessage(data, transfer); }
+		catch (error) {
+			worker.requests.delete(requestKey(worker, data));
+			worker.operations.delete(requestKey(worker, data));
+			worker.receive({data:{engineID:data.engineID, id:data.id, ok:false, error:error.message}});
+		}
+	}
+
+	complete(worker, data) {
+		if (data.memory) worker.memory = data.memory;
+		if (data.id == null || data.type) return;
+		const key = requestKey(worker, data);
+		const started = worker.requests.get(key);
+		const elapsed = data.elapsed ?? (started === undefined ? 0 : performance.now() - started);
+		const operation = worker.operations.get(key), owner = this.owner(worker, data);
+		if (worker.primary && started !== undefined && data.ok && owner) {
+			if (operation?.name === "ofdgoOpen") owner.openTime = elapsed;
+			if (operation?.name === "ofdgoRenderPage") owner.pageTime = owner.pageTime ? owner.pageTime * 0.75 + elapsed * 0.25 : elapsed;
+		}
+		worker.requests.delete(key);
+		worker.operations.delete(key);
+		if (this.memory > this.budget) this.limit = Math.max(1, this.limit - 1);
+		else if (started !== undefined && data.ok && elapsed > 100 && this.memory + Math.max(128 << 20, worker.memory) < this.budget) this.limit = Math.min(this.capacity, this.limit + 1);
+	}
+
+	drain() {
+		if (this.draining) return;
+		this.draining = true;
+		try {
+			if (this.queue.length) for (const worker of [...this.workers].sort((a,b) => b.memory-a.memory)) {
+				if (this.memory + (64 << 20) <= this.budget) break;
+				if (!worker.requests.size) worker.reclaim?.();
+			}
+			this.queue.sort((a, b) => this.priority(a) - this.priority(b) + (a.queued - b.queued) / 2000);
+			for (let i = 0; i < this.queue.length;) {
+				const task = this.queue[i];
+				if (task.worker.closed) { this.queue.splice(i, 1); continue; }
+				if (this.queue.some(previous => previous.worker === task.worker && previous.data.engineID === task.data.engineID && previous.order < task.order)) { i++; continue; }
+				const busy = [...task.worker.operations.values()].some(data => data.engineID === task.data.engineID && data.name !== "ofdgoSaveSnapshot");
+				const snapshot = task.data.name === "ofdgoSaveSnapshot" && [...task.worker.operations.values()].some(data => data.engineID === task.data.engineID && data.name === "ofdgoSaveSnapshot");
+				const active = this.active();
+				const interactive = task.worker.primary && this.owner(task.worker, task.data)?.foreground === true && !task.data.preload && !task.data.background;
+				const foregroundActive = [...this.workers].some(worker => [...worker.operations.values()].some(data => data.name !== "ofdgoSaveSnapshot" && worker.primary && this.owner(worker, data)?.foreground === true && !data.preload && !data.background));
+				const continuing = task.worker.primary && [...task.worker.operations.values()].some(data => data.engineID === task.data.engineID);
+				const available = continuing || active < this.limit || interactive && !foregroundActive && active < this.limit + 1;
+				if (busy || snapshot || !available || !task.worker.primary && active && this.memory + (64 << 20) > this.budget) { i++; continue; }
+				this.queue.splice(i, 1);
+				this.send(task);
+			}
+		} finally { this.draining = false; }
+	}
+
+	cancel(worker, data) {
+		const index = this.queue.findIndex(task => task.worker === worker && requestKey(worker, task.data) === requestKey(worker, data));
+		if (index < 0) return false;
+		const task = this.queue.splice(index, 1)[0];
+		worker.receive({data:{engineID:task.data.engineID, id:data.id, ok:false, canceled:true, error:"操作已取消"}});
+		this.drain();
+		return true;
+	}
+
+	pause(worker, engineID) {
+		const paused = this.queue.filter(task => task.worker === worker && task.data.engineID === engineID && task.data.preload);
+		this.queue = this.queue.filter(task => !paused.includes(task));
+		for (const task of paused) worker.receive({data:{engineID, id:task.data.id, ok:false, canceled:true, error:"预加载已暂停"}});
+	}
+
+	remove(worker) {
+		this.workers.delete(worker);
+		this.queue = this.queue.filter(task => task.worker !== worker);
+		worker.requests.clear();
+		worker.operations.clear();
+		this.drain();
+	}
+}
+
+class BrowserWorker {
+	constructor(options) {
+		engineScheduler ||= new BrowserScheduler();
+		this.primary = !!options.primary;
+		this.shared = !!options.shared;
+		this.engineID = this.shared ? null : `engine-${++engineSequence}`;
+		this.sessions = new Map();
+		this.closingSessions = new Set();
+		this.batch = !options.primary && !options.page;
+		this.requests = new Map();
+		this.operations = new Map();
+		this.foreground = !this.batch;
+		this.pagesPaused = false;
+		this.memory = 64 << 20;
+		this.reservation = 0;
+		this.closed = false;
+		this.url = String(options.url || "./ofdgo_wasm.js");
+		this.worker = new Worker(this.url);
+		engineScheduler.workers.add(this);
+		this.worker.onmessage = event => {
+			if (this.closed || event.data.type === "module") return;
+			engineScheduler.complete(this, event.data);
+			if (event.data.type === "exit" && (!this.shared || !event.data.engineID)) this.terminate();
+			try { this.receive(event); }
+			finally { engineScheduler.drain(); }
+		};
+		this.worker.onerror = event => { this.terminate(); this.fail("onerror", event); };
+		this.worker.onmessageerror = event => { this.terminate(); this.fail("onmessageerror", event); };
+		this.worker.addEventListener("message", event => {
+			if (event.data.type !== "module") return;
+			event.stopImmediatePropagation();
+			engineModule ||= WebAssembly.compileStreaming(fetch("./ofdgo.wasm")).catch(error => { engineModule = null; throw error; });
+			engineModule.then(module => { if (!this.closed) this.worker.postMessage({ type:"module", module }); }, error => { if (!this.closed) this.worker.postMessage({ type:"module", error:error.message }); });
+		});
+		if (!this.shared) this.worker.postMessage({type:"open", engineID:this.engineID});
+	}
+
+	receive(event) {
+		if (!event.data.engineID && !["progress", "exit"].includes(event.data.type)) return;
+		if (!this.shared) {
+			if (event.data.engineID && event.data.engineID !== this.engineID) return;
+			this.onmessage?.(event);
+			return;
+		}
+		if (event.data.type === "closed") {
+			if (!this.closingSessions.delete(event.data.engineID)) return;
+			for (const [key, data] of this.operations) if (data.engineID === event.data.engineID) {
+				this.requests.delete(key);
+				this.operations.delete(key);
+			}
+			if (!this.sessions.size && !this.closingSessions.size) this.terminate();
+			return;
+		}
+		const targets = event.data.engineID ? [this.sessions.get(event.data.engineID)] : [...this.sessions.values()];
+		for (const session of targets) session?.receive(event);
+	}
+
+	fail(name, event) {
+		if (!this.shared) { this[name]?.(event); return; }
+		for (const session of [...this.sessions.values()]) {
+			session.terminate();
+			session[name]?.(event);
+		}
+	}
+
+	postMessage(data, transfer) {
+		if (this.closed) throw new DOMException("引擎已关闭", "AbortError");
+		if (!this.shared) data = {...data, engineID:this.engineID};
+		if (data.type) {
+			if (data.type === "cancel" && engineScheduler.cancel(this, data)) return;
+			this.worker.postMessage(data, transfer);
+		} else engineScheduler.submit(this, data, transfer);
+	}
+
+	setForeground(foreground) {
+		this.foreground = !!foreground;
+		this.pausePages(!this.foreground);
+	}
+
+	pausePages(paused = true) {
+		this.pagesPaused = !!paused;
+		if (this.pagesPaused) engineScheduler.pause(this, this.engineID);
+		engineScheduler.drain();
+	}
+
+	terminate() {
+		if (this.closed) return;
+		this.closed = true;
+		if (engineRuntimes.get(this.url) === this) engineRuntimes.delete(this.url);
+		this.closingSessions.clear();
+		this.worker.terminate();
+		engineScheduler.remove(this);
+	}
+}
+
+class BrowserSession {
+	constructor(options) {
+		const url = String(options.url || "./ofdgo_wasm.js");
+		let runtime = engineRuntimes.get(url);
+		if (!runtime || runtime.closed) {
+			runtime = new BrowserWorker({primary:true, shared:true, url});
+			engineRuntimes.set(url, runtime);
+		}
+		this.runtime = runtime;
+		this.engineID = `engine-${++engineSequence}`;
+		this.requests = new Set();
+		this.foreground = true;
+		this.pagesPaused = false;
+		this.closed = false;
+		runtime.sessions.set(this.engineID, this);
+		runtime.postMessage({type:"open", engineID:this.engineID});
+	}
+
+	receive(event) {
+		if (this.closed) return;
+		if (event.data.id != null && !event.data.type) this.requests.delete(event.data.id);
+		if (event.data.type === "exit") this.terminate();
+		this.onmessage?.(event);
+	}
+
+	postMessage(data, transfer) {
+		if (this.closed) throw new DOMException("引擎已关闭", "AbortError");
+		if (!data.type) this.requests.add(data.id);
+		this.runtime.postMessage({...data, engineID:this.engineID}, transfer);
+	}
+
+	setForeground(foreground) {
+		this.foreground = !!foreground;
+		this.pausePages(!this.foreground);
+	}
+
+	pausePages(paused = true) {
+		this.pagesPaused = !!paused;
+		if (this.pagesPaused) engineScheduler.pause(this.runtime, this.engineID);
+		engineScheduler.drain();
+	}
+
+	terminate() {
+		if (this.closed) return;
+		this.closed = true;
+		this.runtime.sessions.delete(this.engineID);
+		engineScheduler.queue = engineScheduler.queue.filter(task => task.worker !== this.runtime || task.data.engineID !== this.engineID);
+		this.requests.clear();
+		if (!this.runtime.closed) {
+			this.runtime.closingSessions.add(this.engineID);
+			this.runtime.postMessage({type:"close", engineID:this.engineID});
+		}
+		engineScheduler.drain();
+	}
+}
+
+export function createEngineWorker(options = {}) {
+	if (nativeHost) return nativeHost.worker();
+	if (options.page || options.batch) return new BrowserWorker(options);
+	if (options.primary) return new BrowserSession(options);
+	return new BrowserEngine(options);
+}
+
+export async function documentBytes(file) {
+	if (file?.nativeFile) return file;
+	if (file instanceof Blob) return new Response(file.stream()).blob();
+	return new Uint8Array(await file.arrayBuffer());
+}
+
+class BrowserEngine {
+	constructor(options) {
+		this.primary = createEngineWorker({primary:true, url:options.url});
+		this.engineID = this.primary.engineID;
+		this.workerURL = options.url;
+		this.primary.onmessage = event => {
+			const data = event.data;
+			if (data.memory) this.memory = data.memory;
+			if (this.source) this.parallelism = engineScheduler.limit;
+			const rendered = data.id != null && !data.type && this.requests.delete(data.id);
+			this.onmessage?.(event);
+			if (rendered && data.ok) this.dispatchPages();
+		};
+		this.primary.onerror = event => this.onerror?.(event);
+		this.primary.onmessageerror = event => this.onmessageerror?.(event);
+		this.requests = new Map();
+		this.fontRequests = new Map();
+		this.primaryPages = new Set();
+		this.slots = new Set();
+		this.sequence = 0;
+		this.revision = 0;
+		this.memory = 0;
+		this.parallelism = 1;
+		this.budget = engineScheduler.budget;
+		this.closed = false;
+		this.source = null;
+		this.pageSource = null;
+		this.foreground = true;
+		this.pagesPaused = false;
+	}
+
+	configurePages(source) {
+		const current = this.pageSource;
+		const fonts = (source?.fonts || []).map(font => font?.data !== undefined ? {name:font.name, data:font.data} : font);
+		const sameNames = JSON.stringify(source?.fontNames || []) === JSON.stringify(current?.fontNames || []);
+		const sameFonts = current && fonts.length === current.fonts.length && fonts.every((font, index) => font === current.fonts[index] || font?.data !== undefined && font.name === current.fonts[index]?.name && font.data === current.fonts[index]?.data);
+		if (source && current && source.file === current.file && !!source.pdf === !!current.pdf && (source.document || 0) === current.document && (source.version || "") === current.version && source.annotations === current.annotations && source.revision === current.revision && sameFonts && sameNames) return;
+		this.invalidatePages();
+		if (!source || this.closed) return;
+		this.pageSource = {...source, fonts, document:source.document || 0, version:source.version || ""};
+		this.source = {...source, file: source.file instanceof Blob ? source.file : new Blob([source.file])};
+		this.parallelism = engineScheduler.limit;
+	}
+
+	setForeground(foreground) {
+		this.foreground = !!foreground;
+		this.primary.setForeground(this.foreground);
+		for (const slot of this.slots) slot.worker.setForeground(this.foreground);
+		this.pausePages(!this.foreground);
+	}
+
+	pausePages(paused = true) {
+		this.pagesPaused = !!paused;
+		this.primary.pausePages(this.pagesPaused);
+		for (const slot of this.slots) slot.worker.pausePages(this.pagesPaused);
+	}
+
+	invalidatePages() {
+		this.revision++;
+		this.primaryPages.clear();
+		this.source = null;
+		this.pageSource = null;
+		this.parallelism = 1;
+		this.startupTime = 0;
+		this.primary.pageTime = 0;
+		for (const slot of this.slots) this.closeSlot(slot);
+	}
+
+	closeSlot(slot, error = new DOMException("页面加载已取消", "AbortError")) {
+		if (!this.slots.delete(slot)) return;
+		slot.worker.terminate();
+		for (const [id, request] of this.fontRequests) if (request.worker === slot.worker) this.fontRequests.delete(id);
+		slot.rejectReady(error);
+		for (const pending of slot.pending.values()) pending.reject(error);
+		slot.pending.clear();
+	}
+
+	createSlot(source) {
+		const started = performance.now();
+		const worker = createEngineWorker({page:true, url:this.workerURL});
+		worker.setForeground(this.foreground);
+		worker.pausePages(this.pagesPaused);
+		const slot = {worker, pending: new Map(), busy: false, memory: Math.max(128 << 20, this.memory), pages:new Set(), lastPage:0};
+		worker.reservation = slot.memory;
+		worker.reclaim = () => { if (!slot.busy) this.closeSlot(slot); };
+		const ready = new Promise((resolve, reject) => {
+			slot.rejectReady = reject;
+			worker.onmessage = ({data}) => {
+				if (data.memory) slot.memory = data.memory;
+				if (this.source) this.parallelism = engineScheduler.limit;
+				if (data.type === "ready") { resolve(); return; }
+				if (data.type === "exit") { this.closeSlot(slot, new Error("页面加载失败")); return; }
+				if (data.type === "font") {
+					const request = `${slot.worker.engineID}:${data.request}`;
+					this.fontRequests.set(request, {worker:slot.worker, request:data.request});
+					this.onmessage?.({data:{...data, id:slot.requestID, request}});
+					return;
+				}
+				if (data.type) return;
+				const request = slot.pending.get(data.id);
+				if (!request) return;
+				slot.pending.delete(data.id);
+				if (data.ok) request.resolve(data);
+				else request.reject(Object.assign(new Error(data.error), {code:data.code, name:data.canceled ? "AbortError" : "Error"}));
+			};
+			worker.onerror = worker.onmessageerror = () => this.closeSlot(slot, new Error("页面加载失败"));
+		});
+		this.slots.add(slot);
+		slot.ready = ready.then(async () => {
+			let opened = source.pdf
+				? await this.callSlot(slot, "ofdgoOpenPDF", [source.file, source.fonts, null, source.annotations, source.fontNames])
+				: await this.callSlot(slot, "ofdgoOpen", [source.file, source.fonts, source.annotations]);
+			if ((source.document || 0) !== (opened.data.documentIndex || 0)) opened = await this.callSlot(slot, "ofdgoSelectDocument", [source.document]);
+			if ((source.version || "") !== (opened.data.documentVersion || "")) await this.callSlot(slot, "ofdgoSelectVersion", [source.version || ""]);
+			if (this.slots.has(slot)) this.startupTime = performance.now() - started;
+		});
+		slot.ready.catch(() => {});
+		return slot;
+	}
+
+	callSlot(slot, name, args, preload = false) {
+		return new Promise((resolve, reject) => {
+			if (!this.slots.has(slot)) { reject(new DOMException("页面加载已取消", "AbortError")); return; }
+			const id = --this.sequence;
+			slot.pending.set(id, {resolve, reject});
+			try { slot.worker.postMessage({id, name, args, preload}); }
+			catch (error) { slot.pending.delete(id); reject(error); }
+		});
+	}
+
+	pageSlot(data) {
+		if (this.primaryPages.has(data.args[0])) return null;
+		const preferred = [...this.slots].find(slot => !slot.busy && slot.pages.has(data.args[0]));
+		const pending = [...this.requests.values()].filter(slot => slot === null).length - Number(this.requests.has(data.id));
+		if (!preferred && pending <= 0) return null;
+		let slot = preferred || [...this.slots].filter(slot => !slot.busy).sort((a,b) => Math.abs(a.lastPage-data.args[0])-Math.abs(b.lastPage-data.args[0]))[0];
+		const worthwhile = (this.primary.pageTime || 0) * pending >= Math.max(50, this.startupTime || this.primary.openTime || 0);
+		if (!slot && worthwhile && this.foreground && !this.pagesPaused && this.slots.size < this.parallelism - 1
+			&& engineScheduler.memory + Math.max(128 << 20, this.memory) <= this.budget) slot = this.createSlot(this.source);
+		return slot;
+	}
+
+	dispatchPages() {
+		if (this.closed || !this.source || !this.foreground || this.pagesPaused) return;
+		const draining = engineScheduler.draining;
+		engineScheduler.draining = true;
+		try {
+			const queued = engineScheduler.queue.filter(task => task.worker === this.primary.runtime && task.data.engineID === this.engineID).sort((a,b) => a.order-b.order);
+			for (const task of queued) {
+				if (task.data.name !== "ofdgoRenderPage") break;
+				if (this.requests.get(task.data.id) !== null) continue;
+				let slot;
+				try { slot = this.pageSlot(task.data); } catch { break; }
+				if (!slot) break;
+				engineScheduler.queue.splice(engineScheduler.queue.indexOf(task), 1);
+				this.primary.requests.delete(task.data.id);
+				this.renderSlot(slot, task.data, task.transfer);
+			}
+		} finally { engineScheduler.draining = draining; }
+	}
+
+	postMessage(data, transfer) {
+		if (this.closed) return;
+		if (data.type === "font" && typeof data.request === "string") {
+			const request = this.fontRequests.get(data.request);
+			if (request) {
+				this.fontRequests.delete(data.request);
+				request.worker.postMessage({...data, request:request.request}, transfer);
+			}
+			return;
+		}
+		if (!data.type && data.preload && this.pagesPaused) {
+			this.onmessage?.({data:{engineID:this.engineID, id:data.id, ok:false, canceled:true, error:"预加载已暂停"}});
+			return;
+		}
+		if (data.type === "cancel") {
+			const slot = this.requests.get(data.id);
+			if (slot && slot !== this.primary) this.closeSlot(slot);
+			else this.primary.postMessage(data);
+			return;
+		}
+		if (!data.type && data.name !== "ofdgoRenderPage" && ![
+			"ofdgoLoadPDF", "ofdgoDocumentInfo", "ofdgoDocumentVersions", "ofdgoDocumentNavigation", "ofdgoOpenLinks", "ofdgoOutlineLinks", "ofdgoRenderBackends", "ofdgoSVGFontData",
+			"ofdgoSearchPage", "ofdgoPageTextString", "ofdgoResources", "ofdgoResourceReferences", "ofdgoResourceTargets",
+			"ofdgoResourceLocations", "ofdgoFontPreview", "ofdgoFontFaces", "ofdgoFontFace", "ofdgoMatchFontFiles",
+			"ofdgoImages", "ofdgoStructureTargets", "ofdgoStructureObjects", "ofdgoPackageDocuments", "ofdgoVerifySignatures",
+			"ofdgoAnnotationInfos", "ofdgoInvoices", "ofdgoInvoice", "ofdgoExportInvoice", "ofdgoValidateInvoice",
+			"ofdgoActionList", "ofdgoPageSettings", "ofdgoReadAnnotation", "ofdgoPreviewSignatureSeal",
+			"ofdgoExportFormats", "ofdgoOutputFormats", "ofdgoParsePageRange", "ofdgoExportPage", "ofdgoExportDocument",
+			"ofdgoPreparePrint", "ofdgoLayoutPrint", "ofdgoPrintSide", "ofdgoPrintPDF", "ofdgoDiscardPrint",
+			"ofdgoExportAttachment", "ofdgoExportResource", "ofdgoExportMedia", "ofdgoExportVersion"
+		].includes(data.name)) this.invalidatePages();
+		const slot = data.name === "ofdgoRenderPage" && this.source ? this.pageSlot(data) : null;
+		if (!slot) {
+			if (data.name === "ofdgoRenderPage") this.requests.set(data.id, null);
+			this.primary.postMessage(data, transfer);
+			return;
+		}
+		this.renderSlot(slot, data, transfer);
+	}
+
+	renderSlot(slot, data, transfer) {
+		slot.busy = true;
+		slot.requestID = data.id;
+		this.requests.set(data.id, slot);
+		const revision = this.revision;
+		let fallback = false;
+		slot.ready.then(() => this.callSlot(slot, data.name, data.args, !!data.preload)).then(result => {
+			if (revision !== this.revision) throw new DOMException("页面加载已取消", "AbortError");
+			if (this.source.pdf && ((JSON.parse(result.data.annotations || "null") || []).length || result.data.links?.length)) {
+				this.primaryPages.add(data.args[0]);
+				this.requests.set(data.id, this.primary);
+				fallback = true;
+				this.primary.postMessage(data, transfer);
+				return;
+			}
+			slot.lastPage = data.args[0];
+			slot.pages.delete(slot.lastPage);
+			slot.pages.add(slot.lastPage);
+			if (slot.pages.size > 16) slot.pages.delete(slot.pages.values().next().value);
+			if (!this.closed) this.onmessage?.({data: {...result, engineID:this.engineID, id: data.id}});
+		}).catch(error => {
+			if (!this.closed && revision === this.revision && error.name !== "AbortError") {
+				this.closeSlot(slot, error);
+				this.parallelism = Math.max(1, this.slots.size + 1);
+				this.requests.set(data.id, this.primary);
+				fallback = true;
+				this.primary.postMessage(data, transfer);
+				return;
+			}
+			if (!this.closed) this.onmessage?.({data: {engineID:this.engineID, id: data.id, ok: false, error: error.message, canceled: error.name === "AbortError"}});
+		}).finally(() => {
+			if (!fallback) this.requests.delete(data.id);
+			slot.busy = false;
+			slot.worker.reservation = 0;
+			const memory = engineScheduler.memory;
+			if (memory > this.budget) { this.closeSlot(slot); this.parallelism = Math.max(1, this.slots.size + 1); }
+			this.dispatchPages();
+			engineScheduler.drain();
+		});
+	}
+
+	terminate() {
+		if (this.closed) return;
+		this.closed = true;
+		this.invalidatePages();
+		this.primary.terminate();
+		this.requests.clear();
+	}
+}
+
+export function saveFilePicker(options) {
+	return nativeHost ? nativeHost.savePicker(options) : window.showSaveFilePicker ? window.showSaveFilePicker(options) : null;
+}
+
+export function directoryPicker() {
+	return nativeHost ? nativeHost.directoryPicker() : window.showDirectoryPicker({mode:"readwrite"});
+}
+
+class NativeFile {
+	constructor(value) {
+		Object.assign(this, value);
+		if (value.handle) this.handle = new NativeHandle(nativeHost, value.handle);
+		this.byteLength = this.size;
+		this.type ||= "application/octet-stream";
+		if (value.temporary) nativeHost?.resources?.register(this, value.nativeFile);
+	}
+
+	async arrayBuffer(signal) {
+		const response = await fetch(this.url, {signal});
+		if (!response.ok) throw new Error("读取文件失败");
+		return response.arrayBuffer();
+	}
+
+	toJSON() {
+		return {nativeFile:this.nativeFile, size:this.size, name:this.name};
+	}
+
+	async text() {
+		return new TextDecoder().decode(await this.arrayBuffer());
+	}
+}
+
+class NativeHandle {
+	constructor(host, value) {
+		this.host = host;
+		Object.assign(this, value);
+	}
+
+	toJSON() {
+		return {nativeHandle:this.nativeHandle, name:this.name, kind:this.kind};
+	}
+
+	async getFile() {
+		return new NativeFile(await this.host.call("file", {handle:this.nativeHandle}));
+	}
+
+	async getFileHandle(name, options = {}) {
+		return new NativeHandle(this.host, await this.host.call("child", {handle:this.nativeHandle, name, create:!!options.create, directory:false}));
+	}
+
+	async getDirectoryHandle(name, options = {}) {
+		return new NativeHandle(this.host, await this.host.call("child", {handle:this.nativeHandle, name, create:!!options.create, directory:true}));
+	}
+
+	removeEntry(name, options = {}) {
+		return this.host.call("remove", {handle:this.nativeHandle, name, recursive:!!options.recursive});
+	}
+
+	async createWritable() {
+		const {writer} = await this.host.call("write.begin", {handle:this.nativeHandle});
+		return {
+			write: data => this.host.call("write.data", {writer, data}),
+			close: () => this.host.call("write.commit", {writer}),
+			abort: () => this.host.call("write.abort", {writer}),
+		};
+	}
+}
+
+class NativeHost {
+	constructor(bridge) {
+		this.bridge = bridge;
+		this.parallelism = 1;
+		this.cacheBytes = 32 * 1024 * 1024;
+		this.reading = 0;
+		this.readQueue = [];
+		this.resources = typeof FinalizationRegistry === "function" ? new FinalizationRegistry(file => {
+			this.call("release", {file}).catch(() => {});
+		}) : null;
+	}
+
+	call(name, value, signal) {
+		return this.bridge.call(`ofdgo.host.${name}`, value, {signal});
+	}
+
+	async readResource(file, signal) {
+		if (this.reading >= this.parallelism) await new Promise(resolve => this.readQueue.push(resolve));
+		else this.reading++;
+		try {
+			signal?.throwIfAborted();
+			return await file.arrayBuffer(signal);
+		} finally {
+			try { await this.call("release", {file:file.nativeFile}); }
+			finally {
+				const next = this.readQueue.shift();
+				if (next) next();
+				else this.reading--;
+			}
+		}
+	}
+
+	async decode(value, signal) {
+		const reads = [];
+		const visit = (item, field, replace) => {
+			if (!item || typeof item !== "object" || item instanceof Blob || item instanceof ArrayBuffer || ArrayBuffer.isView(item)) return;
+			if (item.nativeFile) {
+				const file = new NativeFile(item);
+				if (field === "file") replace(file);
+				else reads.push(this.readResource(file, signal).then(bytes => replace(field === "blob" ? new Blob([bytes], {type:item.type}) : new Uint8Array(bytes))));
+				return;
+			}
+			for (const [child, content] of Object.entries(item)) {
+				if (content && typeof content === "object") visit(content, Array.isArray(item) ? "" : child, result => item[child] = result);
+			}
+		};
+		visit(value, "", result => value = result);
+		const results = await Promise.allSettled(reads);
+		const failed = results.find(result => result.status === "rejected");
+		if (failed) throw failed.reason;
+		return value;
+	}
+
+	async release(value) {
+		if (value instanceof Blob || value instanceof ArrayBuffer || ArrayBuffer.isView(value)) return;
+		if (value?.nativeFile && value.temporary) {
+			await this.call("release", {file:value.nativeFile}).catch(() => {});
+			return;
+		}
+		if (value && typeof value === "object") {
+			for (const item of Object.values(value)) await this.release(item);
+		}
+	}
+
+	worker() {
+		const host = this;
+		let closed = false;
+		let unsubscribe;
+		let pending = Promise.resolve();
+		let termination = null;
+		const readers = new Set();
+		const inputs = new Set();
+		const requests = new Map();
+		const completions = new Map();
+		const emit = data => {
+			if (data.type === "result") { completions.get(data.id)?.(data.result); return; }
+			if (!closed) worker.onmessage?.({data:{...data, engineID:worker.engineID}});
+		};
+		const ready = host.call("engine.open", {}).then(({engine, parallelism, cacheBytes}) => {
+			worker.engineID = engine;
+			if (closed) return engine;
+			host.parallelism = Math.max(1, parallelism || 1);
+			host.cacheBytes = cacheBytes || host.cacheBytes;
+			unsubscribe = host.bridge.on(`ofdgo.engine.${engine}`, emit);
+			emit({type:"ready"});
+			return engine;
+		}).catch(error => { if (!closed) worker.onerror?.({message:error.message}); throw error; });
+		const worker = {
+			engineID:null,
+			foreground:true,
+			pagesPaused:false,
+			onmessage:null,
+			onerror:null,
+			configurePages() {},
+			setForeground(foreground) {
+				worker.foreground = !!foreground;
+				worker.pausePages(!worker.foreground);
+			},
+			pausePages(paused = true) {
+				worker.pagesPaused = !!paused;
+			},
+			postMessage(data) {
+				if (closed) return;
+				if (data.type === "cancel") {
+					requests.get(data.id)?.abort();
+					return;
+				}
+				if (data.type === "font") return;
+				if (["ofdgoDetectFormat", "ofdgoOpen", "ofdgoOpenPDF"].includes(data.name)) {
+					const input = data.args?.[0];
+					if (input?.nativeFile && !input.temporary) inputs.add(input.nativeFile);
+				}
+				const controller = new AbortController();
+				requests.set(data.id, controller);
+				const parallel = data.name === "ofdgoRenderPage";
+				const barrier = parallel ? pending : Promise.all([pending, ...readers]);
+				const operation = barrier.then(async () => {
+					const engine = await ready;
+					if (closed) return;
+					if (data.preload && worker.pagesPaused) throw new DOMException("预加载已暂停", "AbortError");
+					controller.signal.throwIfAborted();
+					const args = {engine, id:data.id, name:data.name, args:data.args};
+					let result;
+					if (data.name === "ofdgoConvertFile" || data.name === "ofdgoPackFiles") {
+						const completed = new Promise(resolve => completions.set(data.id, resolve));
+						const cancel = () => host.call("engine.cancel", {engine, id:data.id}).catch(() => {});
+						controller.signal.addEventListener("abort", cancel, {once:true});
+						try {
+							await host.call("engine.start", args);
+							if (controller.signal.aborted) cancel();
+							result = await completed;
+							await host.call("engine.finish", {engine, id:data.id});
+						} finally {
+							controller.signal.removeEventListener("abort", cancel);
+							completions.delete(data.id);
+						}
+					} else result = await host.call("engine.call", args, controller.signal);
+					if (closed) { await host.release(result); return; }
+					let decoded;
+					try {
+						controller.signal.throwIfAborted();
+						decoded = await host.decode(result, controller.signal);
+						controller.signal.throwIfAborted();
+					}
+					catch (error) { await host.release(result); throw error; }
+					if (closed) { await host.release(result); return; }
+					emit({id:data.id, ...decoded});
+				}).catch(error => emit({id:data.id, ok:false, error:error.message, code:error.code, canceled:error.name === "AbortError"})).finally(() => requests.delete(data.id));
+				if (parallel) {
+					readers.add(operation);
+					operation.finally(() => readers.delete(operation));
+				} else if (data.name !== "ofdgoSaveSnapshot") pending = operation;
+			},
+			terminate() {
+				if (closed) return termination;
+				closed = true;
+				for (const controller of requests.values()) controller.abort();
+				termination = ready.then(engine => host.call("engine.close", {engine})).catch(() => {}).finally(async () => {
+					unsubscribe?.();
+					for (const resolve of completions.values()) resolve({ok:false, canceled:true, error:"会话已关闭"});
+					completions.clear();
+					await Promise.all([...inputs].map(file => host.call("release", {file}).catch(() => {})));
+					inputs.clear();
+				});
+				return termination;
+			},
+		};
+		ready.catch(() => {});
+		return worker;
+	}
+
+	async savePicker(options) {
+		return new NativeHandle(this, await this.call("save", options));
+	}
+
+	async directoryPicker() {
+		return new NativeHandle(this, await this.call("directory", {}));
+	}
+
+	async fonts() {
+		return (await this.call("fonts", {})).map(({file, ...font}) => ({...font, nativeFile:new NativeFile(file)}));
+	}
+
+	async start(onFiles, onError) {
+		let launching = Promise.resolve();
+		this.bridge.on("ofdgo.launch", values => {
+			launching = launching.then(async () => {
+				try { await onFiles(values.map(value => new NativeFile(value)), true); }
+				finally { await this.call("launch.done", {}); }
+			}).catch(onError);
+		});
+		this.bridge.on("ofdgo.files", async values => {
+			try { await onFiles(values.map(value => new NativeFile(value))); }
+			catch (error) { onError(error); }
+		});
+		this.bridge.on("ofdgo.error", message => onError(new Error(message)));
+		const title = document.querySelector("title");
+		if (title) new MutationObserver(() => this.call("title", {title:document.title}).catch(onError)).observe(title, {childList:true});
+		await this.call("ready", {});
+	}
+
+	async discardFiles(files) {
+		await Promise.all(files.filter(file => file.drop && file.nativeFile).map(file => this.call("drop.release", {file:file.nativeFile})));
+	}
+
+	installFileInputs(onError) {
+		document.addEventListener("click", async event => {
+			const input = event.target;
+			if (!(input instanceof HTMLInputElement) || input.type !== "file" || input.disabled) return;
+			event.preventDefault();
+			try {
+				const files = (await this.call("open", {multiple:input.multiple, directory:input.webkitdirectory, accept:input.accept})).map(value => new NativeFile(value));
+				if (!files.length) return;
+				const transfer = new DataTransfer();
+				for (const file of files) transfer.items.add(new File([], file.name, {type:file.type}));
+				delete input.files;
+				input.files = transfer.files;
+				Object.defineProperty(input, "files", {configurable:true, get:() => input.value ? files : []});
+				input.dispatchEvent(new Event("input", {bubbles:true}));
+				input.dispatchEvent(new Event("change", {bubbles:true}));
+			} catch (error) { if (error.name !== "AbortError") onError(error); }
+		}, true);
+	}
+
+	async download(data, mime, name) {
+		const handle = await this.savePicker({suggestedName:name});
+		const writer = await handle.createWritable();
+		try { await writer.write(data); await writer.close(); }
+		catch (error) { await writer.abort().catch(() => {}); throw error; }
+	}
+}
+
+export const nativeHost = globalThis.guigo ? new NativeHost(globalThis.guigo) : null;

assets/webui/ofdgo_print.js

@@ -0,0 +1,493 @@
+let printQueue = Promise.resolve();
+
+export class PrintDialog {
+	constructor(options) {
+		Object.assign(this, options);
+		const panel = this.panel || document.querySelector("#printPanel");
+		this.el = Object.fromEntries(["Panel", "Form", "Settings", "Printer", "Properties", "Copies", "Collation", "Duplex", "BackReverse", "BackRotate", "Contents", "Scope", "Range", "Parity", "Reverse", "Mode", "Paper", "Width", "Height", "Orientation", "Scaling", "Scale", "MarginTop", "MarginRight", "MarginBottom", "MarginLeft", "Grid", "PageOrder", "Gap", "Binding", "BookletSheets", "SheetFrom", "SheetTo", "Overlap", "Sides", "Rotate", "Grayscale", "Borders", "CropMarks", "Raster", "DPI", "DPIValue", "TileOnlyLarge", "Labels", "Preview", "Previous", "Next", "PreviewNumber", "PageControl", "PageCount", "Status", "Spinner", "ProgressTrack", "ProgressBar", "Cancel", "Submit"].map(name => [name, name === "Panel" ? panel : panel.querySelector(`#print${name}`)]));
+		this.printerOptions = this.el.Printer.innerHTML;
+		this.paperOptions = this.el.Paper.innerHTML;
+		this.settings = new WeakMap();
+		this.queue = Promise.resolve();
+		this.sequence = 0;
+		this.urls = [];
+		this.el.Settings.addEventListener("input", event => { if (event.target === this.el.Printer) this.choosePrinter(); else this.schedule(); });
+		this.el.Properties.addEventListener("click", () => this.properties());
+		this.el.Form.addEventListener("submit", event => { event.preventDefault(); this.print(); });
+		this.el.Cancel.addEventListener("click", () => this.el.Panel.close());
+		this.el.Panel.addEventListener("close", () => this.close());
+		this.el.Panel.addEventListener("cancel", event => { if (this.waiting) event.preventDefault(); });
+		this.el.Previous.addEventListener("click", () => this.preview(this.side - 1));
+		this.el.Next.addEventListener("click", () => this.preview(this.side + 1));
+		this.el.PreviewNumber.addEventListener("change", () => this.preview(Number(this.el.PreviewNumber.value) - 1));
+		this.el.PreviewNumber.addEventListener("keydown", event => {
+			if (event.key !== "Enter") return;
+			event.preventDefault();
+			if (!event.repeat) this.el.PreviewNumber.dispatchEvent(new Event("change"));
+		});
+		this.observer = new ResizeObserver(([entry]) => { this.previewSize = entry.contentRect; this.resize(); });
+		this.observer.observe(this.el.Preview);
+		this.afterPrint = () => { if (this.waiting === "browser") this.finishPrint("打印窗口已关闭"); };
+		this.beforePrint = () => {
+			if (!this.context || !this.el.Panel.open) return;
+			const root = document.querySelector("#ofdgoPrintDocument");
+			if (!root?.children.length) {
+				this.root = root || this.createRoot();
+				this.root.textContent = "请先在OFDGo中打开打印预览，准备完整文档后打印。";
+			}
+		};
+		window.addEventListener("afterprint", this.afterPrint);
+		window.addEventListener("beforeprint", this.beforePrint);
+	}
+
+	open(context) {
+		if (this.context) return;
+		const saved = this.settings.get(context.tab)?.get(context.document);
+		this.context = context;
+		this.restoring = true;
+		this.prepared = false;
+		this.layout = null;
+		this.job = this.profile = null;
+		this.side = 0;
+		this.sequence++;
+		this.el.Printer.innerHTML = this.printerOptions;
+		this.el.Paper.innerHTML = this.paperOptions;
+		this.el.Form.reset();
+		this.orientation = saved?.orientation ?? this.el.Orientation.value;
+		this.duplexBeforeBooklet = saved?.duplex ?? this.el.Duplex.value;
+		this.scalingBeforeBooklet = saved?.scaling ?? this.el.Scaling.value;
+		this.restore(saved);
+		this.mode = this.el.Mode.value;
+		if (!saved) this.el.Scope.value = context.selection.length ? "selected" : "all";
+		this.el.Scope.querySelector('option[value="selected"]').disabled = !context.selection.length;
+		this.el.Sides.value = this.manual() ? "front" : "all";
+		if (!saved) this.el.Contents.value = context.annotations ? "documentAndAnnotations" : "document";
+		this.status();
+		this.el.Preview.replaceChildren();
+		this.show(this.el.Panel);
+		this.loadDevices(saved);
+	}
+
+	isDevice() { return this.el.Printer.value.startsWith("device:"); }
+	manual() { return this.el.Duplex.value.startsWith("manual"); }
+
+	async loadDevices(saved) {
+		const sequence = ++this.sequence;
+		const selected = saved?.values.Printer;
+		this.loading = true;
+		this.controls();
+		const browser = this.el.Printer.querySelector('option[value="browser"]');
+		browser.disabled = !!this.nativeHost || typeof window.print !== "function";
+		if (browser.disabled) this.el.Printer.value = "pdf";
+		try {
+			if (this.nativeHost) {
+				this.status("正在读取设备", true);
+				const capabilities = await this.nativeHost.call("print.capabilities", {});
+				if (!this.current(sequence)) return;
+				this.capabilities = capabilities;
+				browser.disabled = !capabilities.systemDialog;
+				const printers = capabilities.direct ? await this.nativeHost.call("print.printers", {}) : [];
+				if (!this.current(sequence)) return;
+				for (const printer of printers) this.el.Printer.add(new Option(printer.name, `device:${printer.name}`));
+				const printer = printers.find(printer => printer.default) || printers[0];
+				this.el.Printer.value = printer ? `device:${printer.name}` : "pdf";
+			}
+		} catch (error) { if (this.current(sequence)) this.status(error.message); }
+		finally {
+			if (this.current(sequence)) {
+				this.loading = false;
+				if ([...this.el.Printer.options].some(option => option.value === selected && !option.disabled)) this.el.Printer.value = selected;
+				await this.choosePrinter(this.el.Printer.value === selected ? saved : null);
+			}
+		}
+	}
+
+	async choosePrinter(saved) {
+		const sequence = ++this.sequence;
+		const paper = this.el.Paper.value;
+		this.layout = this.job = this.profile = null;
+		this.loading = true;
+		this.status();
+		this.controls();
+		if (!this.isDevice()) {
+			this.el.Paper.innerHTML = this.paperOptions;
+			this.el.Paper.value = paper;
+			if (!this.el.Paper.value) {
+				const [width, height] = paper.split(",").map(Number);
+				if (width > 0 && height > 0 && Number.isFinite(width) && Number.isFinite(height)) {
+					this.el.Paper.value = "custom";
+					this.el.Width.value = width;
+					this.el.Height.value = height;
+				} else this.el.Paper.value = "210,297";
+			}
+		}
+		this.el.Properties.hidden = true;
+		try {
+			if (this.isDevice()) {
+				this.status("正在读取纸张", true);
+				const profile = await this.nativeHost.call("print.query", {printer:this.el.Printer.value.slice(7), copies:1, duplex:"simplex"});
+				if (!this.current(sequence)) return;
+				this.profile = profile;
+				this.el.Paper.replaceChildren(...profile.papers.map(paper => new Option(paper.name, `${paper.width},${paper.height}`)));
+				if (profile.customPaper) this.el.Paper.add(new Option("自定义", "custom"));
+				this.el.Paper.value = `${profile.options.width},${profile.options.height}`;
+				if (!this.el.Paper.value && profile.customPaper) { this.el.Paper.value = "custom"; this.el.Width.value = profile.options.width; this.el.Height.value = profile.options.height; }
+				if (!this.el.Paper.value) throw new Error("设备默认纸张不在支持列表中");
+				this.el.Orientation.value = profile.options.orientation;
+				this.el.Copies.max = Math.min(999, profile.maxCopies || 999);
+				this.el.Copies.value = 1;
+				this.el.Grayscale.checked = profile.options.color === "grayscale";
+				this.el.Grayscale.disabled = !profile.color;
+				this.el.Properties.hidden = !profile.properties;
+			} else this.el.Grayscale.disabled = false;
+		} catch (error) { if (this.current(sequence)) { this.status(error.message); return; } }
+		finally { if (this.current(sequence)) { this.loading = false; this.controls(); } }
+		if (this.current(sequence)) {
+			this.restore(saved);
+			if (this.el.Scope.value === "selected" && !this.context.selection.length) this.el.Scope.value = "all";
+			this.restoring = false;
+			this.schedule();
+		}
+	}
+
+	async properties() {
+		if (!this.isDevice() || this.running || this.loading) return;
+		const sequence = this.sequence;
+		this.loading = true;
+		this.status("正在打开属性", true);
+		this.controls();
+		try { await this.nativeHost.call("print.properties", {printer:this.el.Printer.value.slice(7)}); }
+		catch (error) { if (this.current(sequence)) this.status(error.message); }
+		finally { if (this.current(sequence)) { this.loading = false; await this.choosePrinter(); } }
+	}
+
+	deviceOptions() {
+		const [width, height] = this.el.Paper.value === "custom" ? [Number(this.el.Width.value), Number(this.el.Height.value)] : this.el.Paper.value.split(",").map(Number);
+		const manual = this.manual(), partial = this.el.Sides.value !== "all";
+		return {printer:this.el.Printer.value.slice(7), width, height, orientation:this.el.Orientation.value,
+			copies:Number(this.el.Copies.value), collation:this.el.Collation.checked ? "collated" : "uncollated",
+			duplex:manual || partial ? "simplex" : this.el.Duplex.value, color:this.el.Grayscale.checked ? "grayscale" : "color",
+			scale:1, pagesPerSide:1, margins:{top:0,right:0,bottom:0,left:0},
+			...(this.capabilities?.backgrounds ? {backgrounds:true} : {}), ...(this.capabilities?.headersFooters ? {headersFooters:false} : {})};
+	}
+
+	options(profile) {
+		const el = this.el;
+		const number = name => {
+			const value = Number(el[name].value);
+			if (!el[name].value.trim() || !Number.isFinite(value)) throw new Error("请输入有效数值");
+			return value;
+		};
+		let [paperWidth, paperHeight] = el.Paper.value === "source" ? [0, 0] : el.Paper.value === "custom" ? [number("Width"), number("Height")] : el.Paper.value.split(",").map(Number);
+		if (el.Orientation.value === "landscape") [paperWidth, paperHeight] = [paperHeight, paperWidth];
+		if (profile) [paperWidth, paperHeight] = [profile.width, profile.height];
+		const scope = el.Scope.value;
+		const [rows, columns] = el.Grid.value.split(",").map(Number);
+		if (scope === "selected" && !this.context.selection.length) throw new Error("未选择页面");
+		if (scope === "range" && !el.Range.value.trim()) throw new Error("请输入页码范围");
+		const manual = this.manual(), duplex = el.Duplex.value.replace("manualL", "l").replace("manualS", "s");
+		if (manual && this.isDevice() && number("Copies") !== 1) throw new Error("手动双面每次仅支持1份");
+		return {
+			...(scope === "current" ? {pages:[this.context.page]} : scope === "selected" ? {pages:this.context.selection} : scope === "range" ? {pageRange:el.Range.value.trim()} : {}),
+			mode:el.Mode.value, scaling:el.Scaling.value, paperWidth, paperHeight,
+			margins:{top:number("MarginTop"), right:number("MarginRight"), bottom:number("MarginBottom"), left:number("MarginLeft")},
+			...(profile ? {printableArea:{x:profile.printableArea.x, y:profile.printableArea.y, w:profile.printableArea.width, h:profile.printableArea.height}} : {}),
+			copies:this.isDevice() ? number("Copies") : 1, collate:el.Collation.checked, duplex,
+			scale:el.Scale.disabled ? 1 : number("Scale") / 100, rotate:el.Rotate.checked, reverse:el.Reverse.checked !== (manual && el.Sides.value === "back" && el.BackReverse.checked), parity:el.Parity.value, sides:el.Sides.value,
+			backRotate:manual && el.BackRotate.checked,
+			rows, columns, pageOrder:el.PageOrder.value, gap:el.Gap.disabled ? 0 : number("Gap"), binding:el.Binding.value, bookletSheets:!el.BookletSheets.disabled && el.BookletSheets.value ? number("BookletSheets") : 0, overlap:el.Overlap.disabled ? 0 : number("Overlap"),
+			...(el.Mode.value === "booklet" ? {sheetFrom:el.SheetFrom.value ? number("SheetFrom") : 0, sheetTo:el.SheetTo.value ? number("SheetTo") : 0} : {}),
+			contents:el.Contents.value, grayscale:el.Grayscale.checked, borders:el.Borders.checked, cropMarks:el.CropMarks.checked, raster:el.Raster.checked, dpi:number("DPI"), tileOnlyLarge:el.TileOnlyLarge.checked, labels:el.Labels.checked
+		};
+	}
+
+	schedule() {
+		const el = this.el, mode = el.Mode.value;
+		const source = el.Paper.querySelector('option[value="source"]');
+		if (source) source.disabled = mode !== "single";
+		if (mode !== "single" && el.Paper.value === "source") el.Paper.value = "210,297";
+		if (mode === "booklet" && this.mode !== "booklet") {
+			this.orientation = el.Orientation.value;
+			this.duplexBeforeBooklet = el.Duplex.value;
+			this.scalingBeforeBooklet = el.Scaling.value;
+			el.Scaling.value = "shrink";
+			el.Duplex.value = this.isDevice() && !this.profile?.duplex ? "manualShortEdge" : "shortEdge";
+		} else if (mode !== "booklet" && this.mode === "booklet") {
+			el.Orientation.value = this.orientation;
+			el.Duplex.value = this.duplexBeforeBooklet;
+			el.Scaling.value = this.scalingBeforeBooklet;
+		}
+		if (mode === "booklet") el.Orientation.value = "landscape";
+		this.mode = mode;
+		if (this.isDevice() && !this.profile?.duplex && ["longEdge", "shortEdge"].includes(el.Duplex.value)) el.Duplex.value = el.Duplex.value === "longEdge" ? "manualLongEdge" : "manualShortEdge";
+		if (mode === "booklet" && el.Duplex.value === "simplex") el.Duplex.value = this.isDevice() && !this.profile?.duplex ? "manualShortEdge" : "shortEdge";
+		if (el.Duplex.value === "simplex") el.Sides.value = "all";
+		const isManual = this.manual();
+		el.Sides.querySelector('option[value="all"]').disabled = isManual;
+		if (isManual && el.Sides.value === "all") el.Sides.value = "front";
+		for (const option of el.Duplex.options) option.disabled = this.isDevice() && !this.profile?.duplex && ["longEdge", "shortEdge"].includes(option.value) || mode === "booklet" && ["simplex", "longEdge", "manualLongEdge"].includes(option.value);
+		el.Orientation.disabled = mode === "booklet" || el.Paper.value === "source";
+		const rows = {device:this.isDevice(), sides:el.Duplex.value !== "simplex", manual:isManual, range:el.Scope.value === "range", paper:el.Paper.value === "custom", scale:el.Scaling.value === "custom" || mode === "poster", multiple:mode === "multiple", gap:mode === "multiple" || mode === "booklet", booklet:mode === "booklet", poster:mode === "poster"};
+		for (const row of el.Panel.querySelectorAll("[data-print-row]")) {
+			row.hidden = !rows[row.dataset.printRow];
+			for (const input of row.querySelectorAll("input, select")) input.disabled = row.hidden;
+		}
+		el.Scaling.disabled = mode === "poster" || mode === "booklet";
+		el.DPI.disabled = !el.Raster.checked && !el.Grayscale.checked;
+		const sequence = ++this.sequence;
+		this.layout = null;
+		this.job = null;
+		this.status();
+		this.controls();
+		clearTimeout(this.timer);
+		this.timer = setTimeout(() => {
+			this.queue = this.queue.catch(() => {}).then(() => this.refresh(sequence));
+		}, 160);
+	}
+
+	async refresh(sequence) {
+		if (!this.current(sequence)) return;
+		const context = this.context;
+		try {
+			if (!this.el.Form.checkValidity()) {
+				if (this.el.Panel.open) this.el.Form.reportValidity();
+				else this.status("请检查打印设置");
+				return;
+			}
+			this.status("正在准备预览", true);
+			const deviceOptions = this.isDevice() ? this.deviceOptions() : null;
+			const profile = deviceOptions ? await this.nativeHost.call("print.query", deviceOptions) : null;
+			if (!this.current(sequence)) return;
+			this.profile = profile;
+			const options = this.options(profile);
+			const layout = await context.call(this.prepared ? "ofdgoLayoutPrint" : "ofdgoPreparePrint", options);
+			if (!this.current(sequence)) return;
+			this.prepared = true;
+			this.layout = layout;
+			if (this.isDevice()) this.el.Copies.max = Math.min(999, this.profile.maxCopies || 999, layout.copiesLimit > 0 ? layout.copiesLimit : 999);
+			await this.preview(Math.min(this.side, layout.sides.length - 1));
+			if (!this.current(sequence) || this.layout !== layout) return;
+			this.job = {deviceOptions, fingerprint:profile?.fingerprint, manual:this.manual(), sides:options.sides, backContent:layout.backContent};
+			this.status();
+			if (layout.sides.some(side => side.placements.some(placement => placement.clipped))) this.status("内容超出可打印区域");
+			if (this.manual() && options.sides === "back" && !layout.backContent) this.status("背面为空白");
+		} catch (error) {
+			if (this.current(sequence)) this.status(error.code === "printDenied" ? "文档禁止打印" : error.message);
+		} finally {
+			if (this.current(sequence)) this.controls();
+		}
+	}
+
+	current(sequence = this.sequence) { return sequence === this.sequence && this.context && !this.context.tab.closed; }
+
+	async preview(index) {
+		if (!this.layout || this.running) return;
+		if (!Number.isInteger(index) || index < 0 || index >= this.layout.sides.length) { this.controls(); return; }
+		const sequence = this.sequence, preview = this.previewSequence = (this.previewSequence || 0) + 1;
+		this.side = index;
+		this.controls();
+		try {
+			let {svg} = await this.context.call("ofdgoPrintSide", index);
+			if (!this.current(sequence) || preview !== this.previewSequence) return;
+			if (this.profile) {
+				const area = this.profile.printableArea;
+				svg = svg.replace("</svg>", `<rect x="${area.x}" y="${area.y}" width="${area.width}" height="${area.height}" fill="none" stroke="#88949e" stroke-width="0.2" stroke-dasharray="1 1"/></svg>`);
+			}
+			const url = URL.createObjectURL(new Blob([svg], {type:"image/svg+xml"}));
+			const img = new Image();
+			img.src = url;
+			try { await img.decode(); } catch (error) { URL.revokeObjectURL(url); throw error; }
+			if (!this.current(sequence) || preview !== this.previewSequence) { URL.revokeObjectURL(url); return; }
+			if (this.previewURL) URL.revokeObjectURL(this.previewURL);
+			this.previewURL = url;
+			this.el.Preview.replaceChildren(img);
+			this.resize();
+		} catch (error) { if (this.current(sequence) && preview === this.previewSequence) { this.status(error.message); this.layout = null; this.controls(); } }
+	}
+
+	resize() {
+		const img = this.el.Preview.querySelector("img"), side = this.layout?.sides[this.side];
+		if (!img || !side || !this.previewSize) return;
+		const factor = Math.min(this.previewSize.width / side.width, this.previewSize.height / side.height);
+		img.style.width = `${Math.max(1, side.width * factor)}px`;
+		img.style.height = `${Math.max(1, side.height * factor)}px`;
+	}
+
+	status(text = "", busy = false, completed = 0, total = 0) {
+		this.el.Status.textContent = total ? `${text} · ${completed} / ${total}` : text;
+		this.el.Spinner.hidden = !busy;
+		this.el.ProgressTrack.hidden = !busy || !total;
+		this.el.ProgressBar.style.width = `${total ? completed / total * 100 : 0}%`;
+	}
+
+	controls() {
+		const count = this.layout?.sides.length || 0, busy = !!this.running || !!this.loading;
+		this.el.DPIValue.textContent = this.el.DPI.value;
+		this.el.Settings.disabled = busy;
+		this.el.Submit.disabled = !count || !this.job || busy;
+		if (this.el.Printer.value !== "pdf" && this.manual() && this.el.Sides.value === "back" && !this.layout?.backContent) this.el.Submit.disabled = true;
+		this.el.Previous.disabled = busy || !count || this.side === 0;
+		this.el.Next.disabled = busy || !count || this.side + 1 === count;
+		this.el.PreviewNumber.disabled = busy || !count;
+		this.el.PreviewNumber.max = count || 1;
+		this.el.PreviewNumber.value = count ? this.side + 1 : 1;
+		this.el.PageCount.textContent = String(count);
+		this.el.PageControl.style.setProperty("--page-width", `${String(count || 1).length + 0.5}ch`);
+		this.el.Cancel.textContent = busy && !this.waiting ? "取消" : "关闭";
+		this.el.Cancel.disabled = !!this.waiting;
+	}
+
+	restore(saved) {
+		for (const [name, value] of Object.entries(saved?.values || {})) {
+			if (name === "Printer") continue;
+			const node = this.el[name];
+			if (node.type === "checkbox") node.checked = value;
+			else if (!node.options || [...node.options].some(option => option.value === value)) node.value = value;
+		}
+	}
+
+	remember() {
+		const context = this.context;
+		if (!context || this.restoring) return;
+		let settings = this.settings.get(context.tab);
+		if (!settings) this.settings.set(context.tab, settings = new Map());
+		const values = {};
+		for (const [name, node] of Object.entries(this.el)) if (node.closest("#printSettings") && name !== "Sides" && node.matches("input, select")) values[name] = node.type === "checkbox" ? node.checked : node.value;
+		settings.set(context.document, {values, orientation:this.orientation, duplex:this.duplexBeforeBooklet, scaling:this.scalingBeforeBooklet});
+	}
+
+	createRoot() {
+		const root = document.createElement("div");
+		root.id = "ofdgoPrintDocument";
+		document.body.append(root);
+		return root;
+	}
+
+	async print() {
+		if (!this.layout || !this.job || this.running) return;
+		this.previewSequence++;
+		if (this.el.Printer.value === "pdf") return this.pdf();
+		const sequence = this.sequence, context = this.context;
+		const job = this.job;
+		this.running = true;
+		this.controls();
+		this.status("正在等待打印", true);
+		const previous = printQueue;
+		let release;
+		printQueue = new Promise(resolve => { release = resolve; });
+		await previous;
+		if (!this.current(sequence)) { release(); return; }
+		this.releasePrint = release;
+		try {
+			this.root = document.querySelector("#ofdgoPrintDocument") || this.createRoot();
+			this.root.replaceChildren();
+			const style = document.createElement("style");
+			style.textContent = this.layout.sides.map((side, i) => `@page ofdgoPrint${i}{size:${side.width}mm ${side.height}mm;margin:0}`).join("");
+			this.root.append(style);
+			this.status("正在准备纸面", true, 0, this.layout.sides.length);
+			for (let i = 0; i < this.layout.sides.length; i++) {
+				if (!this.current(sequence)) throw new DOMException("打印已取消", "AbortError");
+				const {svg} = await context.call("ofdgoPrintSide", i);
+				if (!this.current(sequence)) throw new DOMException("打印已取消", "AbortError");
+				const url = URL.createObjectURL(new Blob([svg], {type:"image/svg+xml"}));
+				this.urls.push(url);
+				const img = new Image(), section = document.createElement("section"), side = this.layout.sides[i];
+				img.src = url;
+				section.append(img);
+				section.style.cssText = `page:ofdgoPrint${i};width:${side.width}mm;height:${side.height}mm`;
+				this.root.append(section);
+				await img.decode();
+				if (this.current(sequence)) this.status("正在准备纸面", true, i + 1, this.layout.sides.length);
+			}
+			await document.fonts.ready;
+			if (!this.current(sequence)) throw new DOMException("打印已取消", "AbortError");
+			if (this.el.Panel.open) {
+				this.previousTitle = document.title;
+				document.title = this.printTitle = context.name;
+			}
+			this.waiting = this.nativeHost ? "native" : "browser";
+			this.controls();
+			this.status(job.deviceOptions ? "正在提交打印" : "正在打开打印", true);
+			if (job.deviceOptions) {
+				const result = await this.nativeHost.call("print", {...job.deviceOptions, fingerprint:job.fingerprint});
+				this.finishPrint(result?.submitted ? "打印已提交" : "打印作业未被接受");
+				if (this.current(sequence) && result?.submitted && job.manual && job.sides === "front") {
+					if (job.backContent) { this.el.Sides.value = "back"; this.schedule(); }
+					else this.status("背面为空白");
+				}
+			} else if (this.nativeHost) {
+				const capabilities = await this.nativeHost.call("print.capabilities", {});
+				if (!this.current(sequence)) throw new DOMException("打印已取消", "AbortError");
+				if (!capabilities.systemDialog) throw new Error("当前运行时不支持系统打印");
+				if (!capabilities.dialogCompletion) this.waiting = "browser";
+				await this.nativeHost.call("print.dialog", {kind:"system"});
+				if (capabilities.dialogCompletion) this.finishPrint("打印窗口已关闭");
+			} else if (typeof window.print === "function") window.print();
+			else throw new Error("当前浏览器不支持打印");
+		} catch (error) {
+			if (this.releasePrint === release) this.finishPrint();
+			if (this.current(sequence)) {
+				this.status(error.name === "AbortError" ? "打印已取消" : error.message);
+			}
+		} finally {
+			if (this.current(sequence)) {
+				if (!this.waiting) this.running = false;
+				this.controls();
+			}
+		}
+	}
+
+	finishPrint(message = "") {
+		if (this.previousTitle !== undefined) {
+			if (document.title === this.printTitle) document.title = this.previousTitle;
+			delete this.previousTitle;
+		}
+		if (this.releasePrint) this.root?.replaceChildren();
+		for (const url of this.urls) URL.revokeObjectURL(url);
+		this.urls = [];
+		this.releasePrint?.();
+		this.releasePrint = null;
+		this.status(message);
+		this.waiting = this.running = false;
+		this.controls();
+		if (this.destroyed) window.removeEventListener("afterprint", this.afterPrint);
+	}
+
+	async pdf() {
+		if (!this.layout || this.running) return;
+		const sequence = this.sequence, context = this.context;
+		this.running = true;
+		this.controls();
+		this.status("正在生成文件", true);
+		try {
+			const result = await context.call("ofdgoPrintPDF");
+			if (this.current(sequence)) {
+				await this.download(result.bytes, "application/pdf", `${context.name.replace(/\.[^.]+$/, "")}-打印.pdf`);
+				if (this.current(sequence)) this.status("文件已生成");
+			}
+		} catch (error) { if (this.current(sequence)) this.status(error.message); }
+		finally { if (this.current(sequence)) { this.running = false; this.controls(); } }
+	}
+
+	close() {
+		const context = this.context;
+		this.remember();
+		this.sequence++;
+		clearTimeout(this.timer);
+		if (context) this.cancel(context.tab);
+		if (!this.waiting) this.finishPrint();
+		if (this.previewURL) URL.revokeObjectURL(this.previewURL);
+		this.previewURL = null;
+		this.el.Preview.replaceChildren();
+		this.context = null;
+		this.queue = this.queue.catch(() => {}).then(() => context?.call("ofdgoDiscardPrint").catch(() => {}));
+	}
+
+	destroy() {
+		this.destroyed = true;
+		this.close();
+		this.observer.disconnect();
+		window.removeEventListener("beforeprint", this.beforePrint);
+		if (!this.waiting) window.removeEventListener("afterprint", this.afterPrint);
+	}
+}

assets/webui/ofdgo_theme.js

@@ -0,0 +1,42 @@
+(() => {
+	const root = document.documentElement;
+	const preference = matchMedia("(prefers-color-scheme: dark)");
+	const key = "ofdgo.theme";
+	let mode = root.dataset.themeMode || "system";
+	let host = null, report = null, pending = Promise.resolve();
+	if (!root.dataset.themeMode) {
+		try { mode = localStorage.getItem(key) || "system"; } catch {}
+	}
+	if (!["system", "light", "dark"].includes(mode)) mode = "system";
+	function apply() {
+		root.dataset.themeMode = mode;
+		root.dataset.theme = mode === "system" ? preference.matches ? "dark" : "light" : mode;
+		document.querySelector('meta[name="theme-color"]').content = root.dataset.theme === "dark" ? "#272e33" : "#fafbfc";
+		for (const button of document.querySelectorAll("[data-theme-choice]")) button.dataset.pressed = String(button.dataset.themeChoice === mode);
+	}
+	function sync() {
+		if (!host) return;
+		const value = {mode, dark: root.dataset.theme === "dark"};
+		pending = pending.then(() => host.call("appearance", value)).catch(error => report(error));
+	}
+	function set(value) {
+		mode = value;
+		apply();
+		if (!host) {
+			try { localStorage.setItem(key, mode); } catch {}
+		}
+		sync();
+	}
+	preference.addEventListener("change", () => {
+		if (mode !== "system") return;
+		apply();
+		sync();
+	});
+	window.addEventListener("storage", event => {
+		if (host || event.key !== key && event.key !== null) return;
+		mode = ["light", "dark"].includes(event.newValue) ? event.newValue : "system";
+		apply();
+	});
+	window.ofdgoTheme = {set, connect(value, onError) { host = value; report = onError; apply(); sync(); }};
+	apply();
+})();

assets/webui/ofdgo_util.js

@@ -0,0 +1,550 @@
+export class DocumentDialogs {
+	constructor({ document: root = document, targets = [], titlebar = null } = {}) {
+		Object.assign(this, { document: root, targets, titlebar, owner: null, records: new Map(), tabs: new Map(), released: new WeakSet(), inert: new Map(), styles: new Map() });
+		this.backdrop = root.createElement("div");
+		this.backdrop.className = "document-dialog-backdrop";
+		this.backdrop.hidden = true;
+		Object.assign(this.backdrop.style, { position: "fixed", inset: "0", background: "var(--backdrop)", zIndex: "1000" });
+		root.body.append(this.backdrop);
+		root.addEventListener("keydown", event => {
+			if (event.defaultPrevented || this.applicationOpen()) return;
+			const panel = this.current()?.stack.at(-1);
+			if (!panel) return;
+			if (event.key === "Tab" && !event.ctrlKey && !event.altKey && !event.metaKey) {
+				const selector = "button, input, select, textarea, a[href], [tabindex], [contenteditable=true]";
+				const elements = [this.titlebar, panel].filter(Boolean).flatMap(root => [...root.querySelectorAll(selector)])
+					.filter(node => node.tabIndex >= 0 && !node.disabled && !node.closest("[inert]") && node.getClientRects().length);
+				const index = elements.indexOf(root.activeElement), direction = event.shiftKey ? -1 : 1;
+				const target = index < 0 ? event.shiftKey ? elements.at(-1) : elements[0] : elements[(index + direction + elements.length) % elements.length];
+				event.preventDefault();
+				if (target) target.focus();
+				else panel.focus();
+				return;
+			}
+			if (event.key !== "Escape") return;
+			event.preventDefault();
+			event.stopPropagation();
+			this.cancel(panel);
+		}, true);
+		this.backdrop.addEventListener("pointerdown", event => { event.preventDefault(); this.focus(); });
+		root.defaultView.addEventListener("resize", () => this.paint());
+	}
+
+	register(panel, { shared = true, persistent = false } = {}) {
+		if (this.records.has(panel)) return panel;
+		const record = { show: panel.show.bind(panel), showModal: panel.showModal.bind(panel), close: panel.close.bind(panel), owner: null, application: false, shared, clicks: new WeakMap(), initial: shared && !persistent ? this.snapshot(panel) : null };
+		this.records.set(panel, record);
+		panel.showModal = panel.show = () => this.openFor(this.owner, panel);
+		panel.close = value => {
+			if (record.application) record.close(value);
+			else this.closeFor(this.owner, panel, value);
+		};
+		panel.requestClose = value => {
+			if (record.application) {
+				const event = new this.document.defaultView.Event("cancel", { cancelable: true });
+				if (panel.dispatchEvent(event)) record.close(value);
+			} else this.cancel(panel, value);
+		};
+		panel.addEventListener("close", () => {
+			if (record.application) { record.application = false; this.paint(); }
+		});
+		panel.addEventListener("click", event => { record.clicks.set(event, this.owner); }, true);
+		panel.addEventListener("click", event => {
+			if (!record.application && (record.clicks.get(event) !== this.owner || !this.current()?.stack.includes(panel))) event.preventDefault();
+		});
+		panel.addEventListener("submit", event => {
+			if (record.application || event.defaultPrevented) return;
+			const method = event.submitter?.getAttribute("formmethod") || event.target.getAttribute("method");
+			if (method?.toLowerCase() !== "dialog") return;
+			event.preventDefault();
+			this.closeFor(this.owner, panel, event.submitter?.value || "");
+		});
+		return panel;
+	}
+
+	current(tab = this.owner) {
+		return tab ? this.tabs.get(tab) : null;
+	}
+
+	entry(tab, panel) {
+		if (!tab || this.released.has(tab)) throw new Error("Document dialog owner is unavailable");
+		this.register(panel);
+		if (!this.tabs.has(tab)) this.tabs.set(tab, { entries: new Map(), stack: [] });
+		const entries = this.tabs.get(tab).entries;
+		if (!entries.has(panel)) entries.set(panel, { snapshot: this.records.get(panel).initial, setup: [], updates: [], resolve: null, promise: null });
+		return entries.get(panel);
+	}
+
+	setOwner(tab) {
+		if (this.owner === tab) return;
+		if (this.owner) this.suspend(this.owner);
+		if (tab) this.restore(tab);
+	}
+
+	openFor(tab, panel, setup) {
+		const entry = this.entry(tab, panel);
+		if (setup) entry.setup.push(setup);
+		const state = this.tabs.get(tab);
+		state.stack = state.stack.filter(value => value !== panel);
+		state.stack.push(panel);
+		if (tab !== this.owner) return panel;
+		this.unpaint();
+		this.records.get(panel).owner = tab;
+		this.prepare(entry, panel);
+		if (!this.records.get(panel).shared) this.document.body.append(panel);
+		if (!panel.open) this.records.get(panel).show();
+		this.paint();
+		this.focus();
+		return panel;
+	}
+
+	request(panel, tab = this.owner, setup) {
+		if (!tab || this.released.has(tab)) return Promise.resolve(null);
+		const entry = this.entry(tab, panel);
+		if (entry.promise) return entry.promise;
+		entry.promise = new Promise(resolve => { entry.resolve = resolve; });
+		const promise = entry.promise;
+		this.openFor(tab, panel, setup);
+		return promise;
+	}
+
+	updateFor(tab, panel, setup) {
+		if (!tab || this.released.has(tab)) return false;
+		const entry = this.current(tab)?.entries.get(panel);
+		if (!entry) return false;
+		if (tab === this.owner && this.records.get(panel).owner === tab) setup(panel);
+		else entry.updates.push(setup);
+		return true;
+	}
+
+	closeFor(tab, panel, value) {
+		const state = this.current(tab), entry = state?.entries.get(panel);
+		if (!state?.stack.includes(panel)) return;
+		const visible = tab === this.owner;
+		if (visible) {
+			this.unpaint();
+			if (value !== undefined) panel.returnValue = String(value);
+			panel.removeAttribute("open");
+			if (this.records.get(panel).initial) entry.snapshot = this.snapshot(panel);
+		}
+		const result = value === undefined ? visible ? panel.returnValue : entry.snapshot?.returnValue ?? panel.returnValue : String(value);
+		state.stack = state.stack.filter(value => value !== panel);
+		const resolve = entry.resolve;
+		entry.resolve = entry.promise = null;
+		entry.setup = [];
+		if (visible) {
+			this.paint();
+			panel.dispatchEvent(new this.document.defaultView.Event("close"));
+			this.focus();
+		}
+		resolve?.(result);
+	}
+
+	cancel(panel, value) {
+		const event = new this.document.defaultView.Event("cancel", { cancelable: true });
+		if (panel.dispatchEvent(event)) this.closeFor(this.owner, panel, value);
+	}
+
+	suspend(tab) {
+		if (tab !== this.owner) return;
+		this.unpaint();
+		for (const [panel, entry] of this.current(tab)?.entries || []) {
+			const record = this.records.get(panel);
+			if (record.application || record.owner !== tab) continue;
+			if (record.initial) entry.snapshot = this.snapshot(panel);
+			else if (!record.shared) {
+				entry.focus = panel.contains(this.document.activeElement) ? this.document.activeElement : null;
+				panel.remove();
+			}
+			panel.removeAttribute("open");
+		}
+		this.owner = null;
+		this.paint();
+	}
+
+	restore(tab) {
+		if (!tab || this.released.has(tab)) return false;
+		if (this.owner === tab) return true;
+		if (this.owner) this.suspend(this.owner);
+		if (!this.tabs.has(tab)) this.tabs.set(tab, { entries: new Map(), stack: [] });
+		this.owner = tab;
+		const state = this.current(tab);
+		for (const [panel, entry] of state.entries) {
+			const record = this.records.get(panel);
+			if (record.application) continue;
+			if (record.initial) this.applySnapshot(entry.snapshot, panel);
+			else if (!record.shared) this.document.body.append(panel);
+			record.owner = tab;
+		}
+		for (const [panel, entry] of state.entries) {
+			if (this.records.get(panel).application) continue;
+			for (const update of entry.updates.splice(0)) update(panel);
+		}
+		for (const panel of state.stack) {
+			this.prepare(state.entries.get(panel), panel);
+			if (!panel.open) this.records.get(panel).show();
+		}
+		this.paint();
+		this.focus(true);
+		return true;
+	}
+
+	release(tab) {
+		if (!tab || this.released.has(tab)) return;
+		const visible = this.owner === tab;
+		if (visible) this.suspend(tab);
+		const state = this.current(tab);
+		this.tabs.delete(tab);
+		this.released.add(tab);
+		for (const entry of state?.entries.values() || []) entry.resolve?.(null);
+		for (const [panel] of state?.entries || []) {
+			const record = this.records.get(panel);
+			if (!record.shared) {
+				panel.remove();
+				this.records.delete(panel);
+				continue;
+			}
+			if (record.application || record.owner !== tab) continue;
+			if (record.initial) this.applySnapshot(record.initial, panel);
+			record.owner = null;
+		}
+		state?.entries.clear();
+		if (state) state.stack.length = 0;
+	}
+
+	showApplication(panel) {
+		this.register(panel);
+		if ([...this.tabs.values()].some(state => state.stack.includes(panel))) throw new Error("Document dialog is already in use");
+		const record = this.records.get(panel);
+		record.application = true;
+		try { record.showModal(); }
+		catch (error) { record.application = false; throw error; }
+	}
+
+	applicationOpen() {
+		return [...this.records.values()].some(record => record.application);
+	}
+
+	prepare(entry, panel) {
+		for (const setup of entry.setup.splice(0)) setup(panel);
+	}
+
+	snapshot(panel) {
+		const nodes = [panel, ...panel.querySelectorAll("*")].map(node => ({ node,
+			children: [...node.childNodes], attributes: [...node.attributes].filter(attribute => node !== panel || attribute.name !== "open").map(attribute => [attribute.name, attribute.value]),
+			value: "value" in node && node.type !== "file" ? node.value : undefined,
+			checked: node.checked, indeterminate: node.indeterminate, selected: node.selected,
+			files: node.type === "file" ? [...node.files] : undefined, scrollTop: node.scrollTop, scrollLeft: node.scrollLeft,
+			selectionStart: node.selectionStart, selectionEnd: node.selectionEnd, selectionDirection: node.selectionDirection,
+			text: [...node.childNodes].filter(child => child.nodeType === 3).map(child => [child, child.data]) }));
+		const focus = panel.contains(this.document.activeElement) ? this.document.activeElement : null;
+		const range = this.document.getSelection();
+		const selection = !focus?.matches("input, textarea") && range?.anchorNode && panel.contains(range.anchorNode) && panel.contains(range.focusNode)
+			? { anchor: range.anchorNode, start: range.anchorOffset, focus: range.focusNode, end: range.focusOffset } : null;
+		return { nodes, focus, selection, returnValue: panel.returnValue };
+	}
+
+	applySnapshot(snapshot, panel) {
+		panel.removeAttribute("open");
+		for (const item of snapshot.nodes) {
+			const { node, children, attributes } = item;
+			if (node.childNodes.length !== children.length || children.some((child, index) => node.childNodes[index] !== child)) node.replaceChildren(...children);
+			for (const attribute of [...node.attributes]) if (!attributes.some(([name]) => name === attribute.name)) node.removeAttribute(attribute.name);
+			for (const [name, value] of attributes) if (node.getAttribute(name) !== value) node.setAttribute(name, value);
+			for (const [text, value] of item.text) text.data = value;
+		}
+		for (const item of snapshot.nodes) {
+			const { node } = item;
+			if (item.value !== undefined && node.tagName !== "SELECT") node.value = item.value;
+			for (const key of ["checked", "indeterminate", "selected"]) if (item[key] !== undefined) node[key] = item[key];
+			if (item.files !== undefined) {
+				const transfer = new this.document.defaultView.DataTransfer();
+				for (const file of item.files) transfer.items.add(file);
+				node.files = transfer.files;
+			}
+			if (item.selectionStart != null && typeof node.setSelectionRange === "function") node.setSelectionRange(item.selectionStart, item.selectionEnd, item.selectionDirection);
+			node.scrollTop = item.scrollTop;
+			node.scrollLeft = item.scrollLeft;
+		}
+		panel.returnValue = snapshot.returnValue;
+	}
+
+	unpaint() {
+		for (const [node, value] of this.inert) node.inert = value;
+		this.inert.clear();
+		for (const [panel, styles] of this.styles) for (const [name, [value, priority]] of styles) {
+			if (value) panel.style.setProperty(name, value, priority);
+			else panel.style.removeProperty(name);
+		}
+		this.styles.clear();
+	}
+
+	paint() {
+		this.unpaint();
+		const stack = this.current()?.stack || [];
+		const top = stack.at(-1);
+		this.backdrop.hidden = !top;
+		if (!top) return;
+		const inset = Math.max(0, this.titlebar?.getBoundingClientRect().bottom || 0);
+		this.backdrop.style.top = `${inset}px`;
+		this.backdrop.style.zIndex = String(1000 + (stack.length - 1) * 2);
+		const disable = node => {
+			if (!node || node === this.titlebar || node === this.backdrop || this.records.has(node)) return;
+			if (node.contains(this.titlebar) || [...this.records.keys()].some(panel => node.contains(panel))) {
+				for (const child of node.children) disable(child);
+				return;
+			}
+			if (!this.inert.has(node)) this.inert.set(node, node.inert);
+			node.inert = true;
+		};
+		for (const target of typeof this.targets === "function" ? this.targets() : this.targets) disable(target);
+		for (const [index, panel] of stack.entries()) {
+			if (panel !== top) { this.inert.set(panel, panel.inert); panel.inert = true; }
+			const values = { position: "fixed", inset: `${inset}px 0 0`, zIndex: String(1001 + index * 2), maxHeight: `calc(100dvh - ${inset + 24}px)`, "--dialog-inset": `${inset}px` };
+			const styles = new Map();
+			for (const [key, value] of Object.entries(values)) {
+				const name = key.replace(/[A-Z]/g, letter => `-${letter.toLowerCase()}`);
+				styles.set(name, [panel.style.getPropertyValue(name), panel.style.getPropertyPriority(name)]);
+				panel.style.setProperty(name, value);
+			}
+			this.styles.set(panel, styles);
+		}
+	}
+
+	focus(restore = false) {
+		const panel = this.current()?.stack.at(-1);
+		if (!panel || this.applicationOpen()) return;
+		const saved = restore ? this.current().entries.get(panel)?.snapshot?.focus || this.current().entries.get(panel)?.focus : null;
+		const target = saved?.isConnected && panel.contains(saved) ? saved : panel.querySelector("[autofocus], button:not(:disabled), input:not(:disabled), select:not(:disabled), textarea:not(:disabled), [tabindex]") || panel;
+		if (restore || !panel.contains(this.document.activeElement)) target.focus({ preventScroll: true });
+		const selection = restore && this.current().entries.get(panel)?.snapshot?.selection;
+		if (selection?.anchor?.isConnected && selection.focus?.isConnected) this.document.getSelection().setBaseAndExtent(selection.anchor, selection.start, selection.focus, selection.end);
+		if (restore) for (const item of this.current().entries.get(panel)?.snapshot?.nodes || []) { item.node.scrollTop = item.scrollTop; item.node.scrollLeft = item.scrollLeft; }
+	}
+}
+
+export function positionDropdown(list, anchor, fit = false) {
+	const rect = anchor.getBoundingClientRect(), viewport = window.visualViewport;
+	const left = viewport?.offsetLeft || 0, top = viewport?.offsetTop || 0;
+	const width = viewport?.width || window.innerWidth, height = viewport?.height || window.innerHeight;
+	if (rect.right <= left || rect.left >= left + width || rect.bottom <= top || rect.top >= top + height) return false;
+	const below = top + height - rect.bottom - 12, above = rect.top - top - 12;
+	const limit = Math.min(280, Math.max(below, above));
+	if (limit < 20) return false;
+	const minimum = Math.min(rect.width, width - 16);
+	Object.assign(list.style, { width: fit ? "max-content" : `${minimum}px`, minWidth: `${minimum}px`, maxWidth: `${width - 16}px`, maxHeight: `${limit}px` });
+	const size = list.getBoundingClientRect();
+	Object.assign(list.style, { left: `${Math.max(left + 8, Math.min(rect.left, left + width - size.width - 8))}px`,
+		top: `${below >= size.height || below >= above ? rect.bottom + 4 : rect.top - size.height - 4}px` });
+	return true;
+}
+
+export function bindDropdownPointer(list, choose) {
+	list.addEventListener("pointerdown", event => {
+		if (event.pointerType !== "touch" && event.target.closest("[data-index]")) event.preventDefault();
+	});
+	list.addEventListener("mousedown", event => { if (event.target.closest("[data-index]")) event.preventDefault(); });
+	list.addEventListener("click", event => {
+		const option = event.target.closest("[data-index]");
+		if (option) choose(Number(option.dataset.index));
+	});
+}
+
+export class SelectPicker {
+	constructor(onOpen) {
+		Object.assign(this, { onOpen, select: null, options: [], active: -1, selected: -1, query: "", queryTime: 0, frame: 0, touchClick: false });
+		this.list = document.createElement("div");
+		this.list.className = "dropdown-list";
+		this.list.setAttribute("popover", "manual");
+		bindDropdownPointer(this.list, index => this.choose(index));
+		window.addEventListener("pointerdown", event => {
+			if (event.button !== 0) return;
+			this.touchClick = false;
+			const select = event.target.closest("select");
+			if (select && !select.matches(":disabled")) event.preventDefault();
+			if (this.select && event.target !== this.select && !this.list.contains(event.target)) this.close();
+		}, true);
+		window.addEventListener("pointerup", event => {
+			const select = event.target.closest("select");
+			if (event.pointerType !== "touch" || !select || select.matches(":disabled")) return;
+			event.preventDefault();
+			if (this.select === select) this.close();
+			else this.show(select);
+			this.touchClick = true;
+		}, true);
+		window.addEventListener("mousedown", event => {
+			if (event.button === 0 && event.target.closest("select")) event.preventDefault();
+		}, true);
+		window.addEventListener("click", event => {
+			const select = event.target.closest("select");
+			if (!select || select.matches(":disabled")) return;
+			event.preventDefault();
+			if (this.touchClick) { this.touchClick = false; return; }
+			if (this.select === select) this.close();
+			else this.show(select);
+		}, true);
+		window.addEventListener("keydown", event => this.keyDown(event), true);
+		window.addEventListener("focusin", event => {
+			if (this.select && event.target !== this.select && !this.list.contains(event.target)) this.close();
+		});
+		window.addEventListener("scroll", event => {
+			if (this.select && !this.list.contains(event.target)) this.position();
+		}, true);
+		window.addEventListener("resize", () => this.close());
+		window.addEventListener("blur", () => this.close());
+		window.addEventListener("pagehide", () => this.close());
+		document.addEventListener("close", event => {
+			if (this.select && event.target.contains(this.select)) this.close();
+		}, true);
+		document.addEventListener("reset", event => {
+			if (this.select?.form === event.target) this.close();
+		}, true);
+		document.addEventListener("change", event => {
+			if (event.target === this.select) this.render();
+		}, true);
+	}
+
+	show(select) {
+		this.close();
+		this.onOpen?.();
+		select.focus({ preventScroll: true });
+		if (!select.isConnected || select.matches(":disabled")) return;
+		this.select = select;
+		(select.closest("dialog") || document.body).append(this.list);
+		this.render();
+		if (!this.select) return;
+		this.list.showPopover();
+		this.position();
+		if (!this.select) return;
+		this.activate(this.active);
+		this.observer = new MutationObserver(() => this.render());
+		this.observer.observe(select, { subtree: true, childList: true, characterData: true, attributes: true });
+		this.watch();
+	}
+
+	render() {
+		const select = this.select;
+		if (!select) return;
+		const previous = this.options[this.active]?.option, changed = this.selected !== select.selectedIndex;
+		this.selected = select.selectedIndex;
+		this.options = [...select.options].filter(option => !option.hidden && !option.parentElement.hidden).map(option => ({
+			option, disabled: option.disabled || option.parentElement.tagName === "OPTGROUP" && option.parentElement.disabled,
+		}));
+		if (!this.options.length) { this.close(); return; }
+		this.list.replaceChildren();
+		let group = null;
+		for (const [index, { option, disabled }] of this.options.entries()) {
+			if (option.parentElement.tagName === "OPTGROUP" && group !== option.parentElement) {
+				group = option.parentElement;
+				const heading = document.createElement("div");
+				heading.className = "dropdown-group";
+				heading.textContent = group.label;
+				this.list.append(heading);
+			}
+			const row = document.createElement("div");
+			row.className = "dropdown-option";
+			row.dataset.index = String(index);
+			row.dataset.disabled = String(disabled);
+			const label = document.createElement("span");
+			label.textContent = option.label;
+			row.append(label);
+			row.title = option.title;
+			this.list.append(row);
+		}
+		const selected = this.options.findIndex(({ option, disabled }) => !disabled && option === (changed ? select.selectedOptions[0] : previous));
+		this.activate(selected < 0 ? this.options.findIndex(({ disabled }) => !disabled) : selected);
+		if (this.list.matches(":popover-open")) this.position();
+	}
+
+	watch() {
+		const select = this.select;
+		if (!select) return;
+		if (!select.isConnected || select.matches(":disabled") || !select.getClientRects().length || select.closest("[hidden], [inert], dialog:not([open])")) {
+			this.close();
+			return;
+		}
+		if (this.selected !== select.selectedIndex) this.render();
+		if (this.select) this.frame = requestAnimationFrame(() => this.watch());
+	}
+
+	position() {
+		if (this.select && !positionDropdown(this.list, this.select, true)) this.close();
+	}
+
+	activate(index) {
+		this.active = index;
+		for (const row of this.list.querySelectorAll(".dropdown-option")) {
+			row.dataset.selected = String(Number(row.dataset.index) === index);
+			if (row.dataset.selected === "true" && this.list.matches(":popover-open")) row.scrollIntoView({ block: "nearest" });
+		}
+	}
+
+	choose(index) {
+		const select = this.select, item = this.options[index];
+		if (!select || select.matches(":disabled") || !item || item.disabled || !select.contains(item.option)) return;
+		const changed = select.selectedIndex !== item.option.index;
+		select.selectedIndex = item.option.index;
+		this.close();
+		if (changed) {
+			select.dispatchEvent(new Event("input", { bubbles: true }));
+			select.dispatchEvent(new Event("change", { bubbles: true }));
+		}
+	}
+
+	close() {
+		if (!this.select) return;
+		this.observer?.disconnect();
+		this.observer = null;
+		cancelAnimationFrame(this.frame);
+		this.frame = 0;
+		this.list.hidePopover();
+		this.list.remove();
+		this.list.replaceChildren();
+		this.select = null;
+		this.options = [];
+		this.active = this.selected = -1;
+		this.query = "";
+		this.queryTime = 0;
+	}
+
+	keyDown(event) {
+		if (event.defaultPrevented || event.isComposing) return;
+		this.touchClick = false;
+		if (event.ctrlKey || event.metaKey || event.key === "Tab") { this.close(); return; }
+		const select = event.target.closest("select");
+		if (!select || select.matches(":disabled") || event.altKey && !["ArrowDown", "ArrowUp"].includes(event.key)) return;
+		const key = event.key, open = this.select === select;
+		if (key === "Escape") {
+			if (!open) return;
+			this.close();
+		} else if (key === "F4" || event.altKey) {
+			if (open) this.close();
+			else this.show(select);
+		} else if (["Enter", " "].includes(key)) {
+			if (open) this.choose(this.active);
+			else this.show(select);
+		} else if (["ArrowDown", "ArrowUp", "Home", "End", "PageDown", "PageUp"].includes(key)) {
+			if (!open) this.show(select);
+			if (this.select && (open || !["ArrowDown", "ArrowUp"].includes(key))) {
+				const available = this.options.flatMap(({ disabled }, index) => disabled ? [] : [index]);
+				const at = available.indexOf(this.active), direction = ["ArrowUp", "PageUp"].includes(key) ? -1 : 1;
+				const step = key.startsWith("Page") ? Math.max(1, Math.floor(this.list.clientHeight / (this.list.querySelector(".dropdown-option")?.offsetHeight || 32)) - 1) : 1;
+				const next = key === "Home" ? 0 : key === "End" ? available.length - 1 : Math.max(0, Math.min(available.length - 1, at + direction * step));
+				this.activate(available[next] ?? -1);
+			}
+		} else if (key.length === 1) {
+			if (!open) this.show(select);
+			const now = performance.now();
+			this.query = (now - this.queryTime < 700 ? this.query : "") + key.toLocaleLowerCase();
+			this.queryTime = now;
+			const repeated = [...this.query].every(value => value === this.query[0]), query = repeated ? this.query[0] : this.query;
+			const start = repeated ? this.active + 1 : Math.max(0, this.active);
+			for (let offset = 0; offset < this.options.length; offset++) {
+				const index = (start + offset) % this.options.length, item = this.options[index];
+				if (!item.disabled && item.option.label.trim().toLocaleLowerCase().startsWith(query)) { this.activate(index); break; }
+			}
+		} else return;
+		event.preventDefault();
+		event.stopImmediatePropagation();
+	}
+}

assets/webui/ofdgo_wasm.js

@@ -1,11 +1,15 @@
 importScripts("./wasm_exec.js");
 
-let pending = Promise.resolve();
-const operations = new Map();
-const fontRequests = new Map();
+const engines = new Map();
+let resolveRuntime;
+let rejectRuntime;
+const runtimeReady = new Promise((resolve, reject) => { resolveRuntime = resolve; rejectRuntime = reject; });
+runtimeReady.catch(() => {});
 let fontSequence = 0;
+let engineMemory = null;
 
-function requestFont(id, signal, name, done) {
+function requestFont(engine, id, signal, name, done) {
+	const fontRequests = engine.fontRequests;
 	if (signal.aborted) { done(null, "", true); return; }
 	const request = ++fontSequence;
 	const cancel = () => {
@@ -17,22 +21,79 @@ function requestFont(id, signal, name, done) {
 		signal.removeEventListener("abort", cancel);
 		done(result.bytes, result.error || "", signal.aborted);
 	});
-	self.postMessage({ id, type: "font", request, name });
+	self.postMessage({ engineID: engine.id, id, type: "font", request, name });
 }
 self.onmessage = ({ data }) => {
+	if (data.type === "module") {
+		if (data.error) exitWASM(new Error(data.error));
+		else loadWASM(data.module).catch(exitWASM);
+		return;
+	}
+	const engineID = data.engineID;
+	if (typeof engineID !== "string" || !engineID) {
+		self.postMessage({ engineID, id: data.id, ok: false, error: "missing engine ID" });
+		return;
+	}
+	if (data.type === "open") {
+		if (engines.has(engineID)) {
+			self.postMessage({ engineID, type: "exit", error: "engine already exists" });
+			return;
+		}
+		const engine = { id: engineID, operations: new Map(), fontRequests: new Map(), active: new Set(), closed: false };
+		engines.set(engineID, engine);
+		engine.pending = runtimeReady.then(async () => {
+			if (engine.closed) return;
+			const opened = JSON.parse(globalThis.ofdgoEngineOpen(engineID));
+			if (!opened.ok) throw new Error(opened.error);
+			const backends = JSON.parse(await globalThis.ofdgoEngineCall(engineID, "ofdgoRenderBackends", null));
+			if (!backends.ok) throw new Error(backends.error);
+			if (!engine.closed) self.postMessage({ engineID, type: "ready", backends: backends.data, memory: engineMemory.buffer.byteLength });
+		}).catch(error => {
+			engine.closed = true;
+			self.postMessage({ engineID, type: "exit", error: error.message });
+		});
+		return;
+	}
+	const engine = engines.get(engineID);
+	if (!engine && data.type === "close") {
+		self.postMessage({ engineID, type: "closed" });
+		return;
+	}
+	if (!engine || engine.closed && data.type !== "close") {
+		self.postMessage({ engineID, id: data.id, ok: false, error: "unknown or closed engine" });
+		return;
+	}
+	if (data.type === "close") {
+		engine.closed = true;
+		for (const operation of engine.operations.values()) operation.abort();
+		engine.pending.then(async () => {
+			await Promise.all([...engine.active]);
+			await runtimeReady;
+			globalThis.ofdgoEngineClose(engineID);
+			engines.delete(engineID);
+			self.postMessage({ engineID, type: "closed" });
+		}).catch(() => engines.delete(engineID));
+		return;
+	}
 	if (data.type === "font") {
-		fontRequests.get(data.request)?.(data);
-		fontRequests.delete(data.request);
+		engine.fontRequests.get(data.request)?.(data);
+		engine.fontRequests.delete(data.request);
 		return;
 	}
 	if (data.type === "cancel") {
-		operations.get(data.id)?.abort();
+		engine.operations.get(data.id)?.abort();
 		return;
 	}
-	if (data.name === "ofdgoImportImages" || data.name === "ofdgoExportImages" || data.name === "ofdgoConvertFile" || data.name === "ofdgoPackFiles" || data.name === "ofdgoConvertPDF" || data.name === "ofdgoExportPage" || data.name === "ofdgoExportDocument" || data.name === "ofdgoExportAttachment" || data.name === "ofdgoExportMedia" || data.name === "ofdgoSaveDocument" || data.name === "ofdgoSaveSigned" || data.name === "ofdgoImportPages") {
-		operations.set(data.id, new AbortController());
-	}
-	pending = pending.then(() => data.name === "ofdgoConvertFile" || data.name === "ofdgoPackFiles" ? handleBatchMessage(data) : handleMessage(data));
+	engine.operations.set(data.id, new AbortController());
+	engine.pending = engine.pending.then(() => {
+		const operation = (data.name === "ofdgoConvertFile" || data.name === "ofdgoPackFiles" ? handleBatchMessage(engine, data) : handleMessage(engine, data)).catch(error => {
+			engine.operations.delete(data.id);
+			self.postMessage({ engineID, id: data.id, ok: false, error: error.message });
+		});
+		engine.active.add(operation);
+		operation.finally(() => engine.active.delete(operation));
+		if (data.name !== "ofdgoSaveSnapshot") return operation;
+	});
 };
 
 async function availableOutput(directory, base, format) {
@@ -48,7 +109,9 @@ async function availableOutput(directory, base, format) {
 	}
 }
 
-async function handleBatchMessage({ id, name, args }) {
+async function handleBatchMessage(engine, { id, name, args }) {
+	const operations = engine.operations;
+	const postMessage = (data, transfer) => self.postMessage({ ...data, engineID: engine.id }, transfer);
 	const signal = operations.get(id).signal;
 	const channel = new MessageChannel();
 	const finish = (done, err) => {
@@ -78,17 +141,20 @@ async function handleBatchMessage({ id, name, args }) {
 		if (name === "ofdgoConvertFile") {
 			const [file, options, fonts, destination] = args;
 			credentials = options.credentials;
-			const formats = JSON.parse(globalThis.ofdgoOutputFormats()).data;
+			const formats = JSON.parse(await globalThis.ofdgoEngineCall(engine.id, "ofdgoOutputFormats", null)).data;
 			const format = formats.find(item => item.value === options.format);
 			if (!format) throw new Error("不支持此格式");
 			root = destination;
 			const base = options.base.replace(/[<>:"/\\|?*\x00-\x1f]/g, "_").replace(/[. ]+$/g, "") || "document";
-			const target = root ? await availableOutput(root, base, format) : { stem: base, name: format.paged ? base : `${base}.${format.extension}` };
-			if (root && format.paged) {
-				directory = await root.getDirectoryHandle(target.name, { create: true });
+			const target = root ? await navigator.locks.request("ofdgo-convert-output", { signal }, async () => {
+				signal.throwIfAborted();
+				const target = await availableOutput(root, base, format);
+				if (format.paged) directory = await root.getDirectoryHandle(target.name, { create: true });
+				else { await root.getFileHandle(target.name, { create: true }); directory = root; }
 				created = target.name;
-				self.postMessage({ id, type: "output", name: created });
-			} else directory = root;
+				postMessage({ id, type: "output", name: created });
+				return target;
+			}) : { stem: base, name: format.paged ? base : `${base}.${format.extension}` };
 			const boundary = async (action, pageName) => {
 				signal.throwIfAborted();
 				if (action === "open") {
@@ -99,7 +165,7 @@ async function handleBatchMessage({ id, name, args }) {
 						const handle = await directory.getFileHandle(fileName, { create: true });
 						if (!format.paged) {
 							created = fileName;
-							self.postMessage({ id, type: "output", name: created });
+							postMessage({ id, type: "output", name: created });
 						}
 						current.handle = handle;
 						output = await handle.createWritable();
@@ -112,19 +178,19 @@ async function handleBatchMessage({ id, name, args }) {
 					chunks = [];
 				}
 			};
-			payload = await globalThis.ofdgoConvertFile(read(file), file.size, options, write,
+			payload = await globalThis.ofdgoEngineCall(engine.id, "ofdgoConvertFile", done => finish(done), read(file), file.size, options, write,
 				(phase, completed, total, done) => {
-					self.postMessage({ id, type: "conversion", phase, completed, total });
+					postMessage({ id, type: "conversion", phase, completed, total, memory: engineMemory.buffer.byteLength });
 					finish(done);
 				},
 				(action, pageName, done) => boundary(action, pageName).then(() => finish(done), err => finish(done, err)),
-				done => finish(done), fonts, (name, done) => requestFont(id, signal, name, done));
+				done => finish(done), fonts, (name, done) => requestFont(engine, id, signal, name, done));
 		} else {
 			const [entries, handle, compression] = args;
 			if (handle) output = await handle.createWritable();
-			payload = await globalThis.ofdgoPackFiles(entries.map(entry => ({ name: entry.name, size: entry.file.size })),
+			payload = await globalThis.ofdgoEngineCall(engine.id, "ofdgoPackFiles", done => finish(done), entries.map(entry => ({ name: entry.name, size: entry.file.size })),
 				index => read(entries[index].file), write,
-				(completed, total, done) => { self.postMessage({ id, type: "conversion", phase: "pack", completed, total }); finish(done); },
+				(completed, total, done) => { postMessage({ id, type: "conversion", phase: "pack", completed, total, memory: engineMemory.buffer.byteLength }); finish(done); },
 				done => finish(done), compression);
 		}
 		signal.throwIfAborted();
@@ -143,7 +209,7 @@ async function handleBatchMessage({ id, name, args }) {
 		}
 		result.data.size = size;
 		operations.delete(id);
-		self.postMessage({ id, ...result });
+		postMessage({ id, ...result, memory: engineMemory.buffer.byteLength });
 	} catch (err) {
 		await output?.abort().catch(() => {});
 		let message = signal.aborted ? "转换已取消" : err.message;
@@ -151,7 +217,7 @@ async function handleBatchMessage({ id, name, args }) {
 			try { await root.removeEntry(created, { recursive: true }); }
 			catch (cleanupError) { message += `；清理失败：${cleanupError.message}`; }
 		}
-		self.postMessage({ id, ok: false, error: message, code: err.code, canceled: signal.aborted });
+		postMessage({ id, ok: false, error: message, code: err.code, canceled: signal.aborted, memory: engineMemory.buffer.byteLength });
 	} finally {
 		credentials?.password?.fill(0);
 		credentials?.key?.fill(0);
@@ -161,18 +227,32 @@ async function handleBatchMessage({ id, name, args }) {
 		operations.delete(id);
 	}
 }
-async function handleMessage({ id, name, args }) {
+async function handleMessage(engine, { id, name, args }) {
+	const operations = engine.operations;
+	const postMessage = (data, transfer) => self.postMessage({ ...data, engineID: engine.id }, transfer);
 	let output;
+	let saveFile;
+	let saveStamp;
 	let channel;
 	const signal = operations.get(id)?.signal;
-	const importing = name === "ofdgoImportPages" || name === "ofdgoImportImages";
-	const converting = name === "ofdgoConvertPDF";
-	const saving = name === "ofdgoSaveDocument" || name === "ofdgoSaveSigned";
+	const cancellable = ["ofdgoPreparePrint", "ofdgoLayoutPrint", "ofdgoPrintSide", "ofdgoPrintPDF", "ofdgoResources", "ofdgoPrepareSave", "ofdgoSaveSnapshot", "ofdgoImportDocuments", "ofdgoImportImages", "ofdgoExportImages", "ofdgoOpenPDF", "ofdgoExportPage", "ofdgoExportDocument", "ofdgoExportAttachment", "ofdgoExportResource", "ofdgoExportMedia", "ofdgoExportVersion", "ofdgoSaveDocument", "ofdgoSaveSigned", "ofdgoImportPages"].includes(name);
+	const importing = name === "ofdgoImportPages" || name === "ofdgoImportImages" || name === "ofdgoImportDocuments";
+	const converting = name === "ofdgoOpenPDF";
+	const saving = name === "ofdgoSaveDocument" || name === "ofdgoSaveSnapshot" || name === "ofdgoSaveSigned";
+	const resources = ["ofdgoPreparePrint", "ofdgoLayoutPrint", "ofdgoPrintSide", "ofdgoPrintPDF", "ofdgoResources", "ofdgoPrepareSave"].includes(name);
+	if (engine.pdf) {
+		const checked = JSON.parse(await globalThis.ofdgoEngineCall(engine.id, "ofdgoCheckDocument", null, name));
+		if (!checked.ok) { postMessage({id, ...checked}); operations.delete(id); return; }
+	}
 	const key = name === "ofdgoOpen" ? args[3]?.key : name === "ofdgoSaveSigned" || name === "ofdgoLoadImport" ? args[1]?.key : null;
 	const keyPassword = name === "ofdgoOpen" ? args[3]?.keyPassword : name === "ofdgoSaveSigned" || name === "ofdgoLoadImport" ? args[1]?.keyPassword : null;
 	const password = converting ? args[2] : name === "ofdgoSetEncryption" ? args[0]?.password : name === "ofdgoOpen" ? args[3]?.password : name === "ofdgoLoadImport" ? args[1]?.password : null;
 	try {
 		signal?.throwIfAborted();
+		if (["ofdgoOpen", "ofdgoOpenPDF", "ofdgoLoadImport"].includes(name) && args[0] instanceof Blob) {
+			const file = args[0], reader = new FileReaderSync();
+			args[0] = {size: file.size, read: (offset, size) => new Uint8Array(reader.readAsArrayBuffer(file.slice(offset, offset + size)))};
+		}
 		if (name === "ofdgoDetectFormat") {
 			const file = args[0], reader = new FileReaderSync();
 			channel = new MessageChannel();
@@ -188,6 +268,9 @@ async function handleMessage({ id, name, args }) {
 				catch (err) { return { error: err.message }; }
 			};
 		}
+		if (name === "ofdgoChangeResource" && (args[0] === "add" || args[0] === "replace")) {
+			args[4] = new Uint8Array(new FileReaderSync().readAsArrayBuffer(args[4]));
+		}
 		if (name === "ofdgoImportImages") {
 			const files = args[0], reader = new FileReaderSync();
 			args[0] = files.map(file => file.name);
@@ -198,7 +281,7 @@ async function handleMessage({ id, name, args }) {
 		}
 		const chunks = [];
 		let size = 0;
-		if (signal) {
+		if (cancellable) {
 			channel = new MessageChannel();
 			const finish = (done, err, commit = false) => {
 				channel.port1.onmessage = () => {
@@ -207,14 +290,19 @@ async function handleMessage({ id, name, args }) {
 				};
 				channel.port2.postMessage(null);
 			};
-			if (importing || converting) {
+			if (resources) {
+				args.push(done => finish(done));
+			} else if (importing || converting) {
 				args.push((phase, completed, total, done) => {
-					self.postMessage({ id, type: importing ? "import" : "conversion", phase, completed, total });
+					postMessage({ id, type: importing ? "import" : "conversion", phase, completed, total });
 					finish(done, null, importing && phase === "commit");
 				});
-				if (converting) args.push((name, done) => requestFont(id, signal, name, done));
+				if (converting) args.push((name, done) => requestFont(engine, id, signal, name, done));
 			} else {
-				const file = args.pop();
+				const destination = args.pop();
+				const file = destination?.fileHandle || destination;
+				saveFile = file;
+				saveStamp = destination?.saveStamp;
 				const compression = saving && name !== "ofdgoSaveSigned" && args.at(-1)?.mode !== undefined ? args.pop() : null;
 				const indices = saving ? args.shift() : null;
 				if (file) output = await file.createWritable();
@@ -234,28 +322,55 @@ async function handleMessage({ id, name, args }) {
 				});
 				if (name === "ofdgoExportDocument") {
 					args.push((completed, total, done) => {
-						self.postMessage({ id, type: "export", stage: "pages", completed, total });
+						postMessage({ id, type: "export", stage: "pages", completed, total });
 						finish(done);
 					});
+				} else if (name === "ofdgoExportVersion") {
+					args.push((phase, completed, total, done) => {
+						postMessage({ id, type: "export", stage: "prepare", phase, completed, total });
+						finish(done);
+					}, done => finish(done));
 				} else if (saving) {
 					args.push((phase, completed, total, done) => {
-						self.postMessage({ id, type: "export", stage: "prepare", phase, completed, total });
+						postMessage({ id, type: "export", stage: "prepare", phase, completed, total });
 						finish(done);
 					});
-					if (compression) args.push(indices, compression, done => finish(done));
+					if (compression || name === "ofdgoSaveSnapshot") args.push(indices, compression || {mode: 0}, done => finish(done));
 					else if (indices != null) args.push(indices);
 				}
 				if (!saving && args.some(value => value?.mode !== undefined)) args.push(done => finish(done));
 			}
 		}
-		const payload = await globalThis[name](...args);
+		if (engine.pdf && name !== "ofdgoOpenPDF") {
+			channel ||= new MessageChannel();
+			const context = await globalThis.ofdgoEngineCall(engine.id, "ofdgoPDFContext", null, (phase, completed, total, done) => {
+				postMessage({id, type: "conversion", phase, completed, total});
+				channel.port1.onmessage = () => done("", signal.aborted);
+				channel.port2.postMessage(null);
+			}, (name, done) => requestFont(engine, id, signal, name, done));
+			engine.pdf = JSON.parse(context).data === true;
+		}
+		const started = name === "ofdgoOpen" || name === "ofdgoRenderPage" ? performance.now() : null;
+		const payload = await globalThis.ofdgoEngineCall(engine.id, name, done => {
+			channel ||= new MessageChannel();
+			channel.port1.onmessage = () => done("", signal.aborted);
+			channel.port2.postMessage(null);
+		}, ...args);
 		signal?.throwIfAborted();
 		const result = typeof payload === "string" ? JSON.parse(payload) : payload;
-		if (signal && !importing && !converting && result.ok) {
-			operations.delete(id);
+		if (result.ok && name === "ofdgoOpenPDF") engine.pdf = true;
+		if (result.ok && (name === "ofdgoOpen" || name === "ofdgoLoadPDF" && result.data.done)) engine.pdf = false;
+		if (started !== null && result.ok) result.elapsed = performance.now() - started;
+		if (cancellable && !importing && !converting && !resources && result.ok) {
 			result.data.size = size;
-			if (name !== "ofdgoExportMedia") self.postMessage({ id, type: "export", stage: "save" });
+			if (name !== "ofdgoExportMedia") postMessage({ id, type: "export", stage: "save" });
 			if (output) {
+				if (saveStamp) {
+					const current = await saveFile.getFile();
+					if (current.size !== saveStamp.size || current.lastModified !== saveStamp.modified) throw new Error("文件已被修改，请另存");
+				}
+				signal.throwIfAborted();
+				operations.delete(id);
 				await output.close();
 			} else {
 				result.data.blob = new Blob(chunks, { type: result.data.mime });
@@ -264,16 +379,16 @@ async function handleMessage({ id, name, args }) {
 			await output.abort();
 		}
 		output = null;
-		const transfer = result.data?.bytes ? [result.data.bytes.buffer] : (result.data?.images || []).map((image) => image.bytes.buffer);
-		self.postMessage({ id, ...result }, transfer);
+		const transfer = [...new Set([result.data?.bytes, ...(result.data?.images || []).map(image => image.bytes), ...(result.data?.fonts || []).map(font => font.data)].filter(bytes => bytes?.byteLength).map(bytes => bytes.buffer))];
+		postMessage({ id, ...result, memory: engineMemory.buffer.byteLength }, transfer);
 	} catch (err) {
 		await output?.abort().catch(() => {});
-		const result = { id, ok: false, error: err.message };
+		const result = { id, ok: false, error: err.message, errorName: err.name };
 		if (signal?.aborted) {
-			result.error = importing ? "导入已取消" : converting ? "转换已取消" : "导出已取消";
+			result.error = resources ? "查询已取消" : importing ? "导入已取消" : converting ? "转换已取消" : cancellable ? "导出已取消" : "操作已取消";
 			result.canceled = true;
 		}
-		self.postMessage(result);
+		postMessage(result);
 	} finally {
 		password?.fill(0);
 		key?.fill(0);
@@ -285,23 +400,20 @@ async function handleMessage({ id, name, args }) {
 }
 
 function exitWASM(err) {
+	rejectRuntime(err || new Error("引擎运行中断"));
 	self.postMessage({ type: "exit", error: err?.message || "引擎运行中断" });
 	self.close();
 }
 
-async function loadWASM() {
+async function loadWASM(module) {
 	const go = new Go();
-	self.postMessage({ type: "progress", phase: "download", text: "正在下载引擎", percent: 16 });
-	const response = await fetch("./ofdgo.wasm");
-	self.postMessage({ type: "progress", phase: "compile", text: "正在编译引擎", percent: 35 });
-	const { instance } = await WebAssembly.instantiateStreaming(response, go.importObject);
+	const instance = await WebAssembly.instantiate(module, go.importObject);
+	engineMemory = instance.exports.mem;
 	self.postMessage({ type: "progress", phase: "start", text: "正在启动引擎", percent: 58 });
 	go.run(instance).then(exitWASM, exitWASM);
 	if (!go.exited) {
-		const backends = JSON.parse(globalThis.ofdgoRenderBackends());
-		if (!backends.ok) throw new Error(backends.error);
-		self.postMessage({ type: "ready", backends: backends.data });
+		resolveRuntime();
 	}
 }
 
-loadWASM().catch(exitWASM);
+self.postMessage({ type: "module" });

assets/webui/ofdgo_work.js

@@ -1,6 +1,6 @@
 const CACHE_PREFIX = `ofdgo:${self.registration.scope}:app:`;
 const META_CACHE = `${CACHE_PREFIX}meta`;
-const ASSETS = ["./", "ofdgo.css", "ofdgo.js", "ofdgo.json", "ofdgo.svg", "ofdgo.wasm", "ofdgo_edit.js", "ofdgo_font.js", "ofdgo_wasm.js", "ofdgo_work.js", "wasm_exec.js"]
+const ASSETS = ["./", "ofdgo.css", "ofdgo.ico", "ofdgo.js", "ofdgo.json", "ofdgo.png", "ofdgo.svg", "ofdgo.wasm", "ofdgo_edit.js", "ofdgo_font.js", "ofdgo_host.js", "ofdgo_print.js", "ofdgo_theme.js", "ofdgo_util.js", "ofdgo_view.js", "ofdgo_wasm.js", "ofdgo_work.js", "wasm_exec.js"]
 	.map((path) => new URL(path, self.registration.scope).href);
 const CLIENT_PREFIX = new URL("__client/", self.registration.scope).href;
 
@@ -92,6 +92,8 @@ async function readResource(event, navigation) {
 		bundle = await readBundle(meta, CLIENT_PREFIX + event.clientId);
 	}
 	if (!bundle || !await caches.has(bundle.name)) {
+		const client = await self.clients.get(event.clientId);
+		if (client && resourceURL(client.url) !== self.registration.scope) return fetch(event.request);
 		return Response.error();
 	}
 	if (event.resultingClientId) {
@@ -106,8 +108,9 @@ async function readResource(event, navigation) {
 }
 
 async function updateBundle(meta) {
+	const signal = AbortSignal.timeout(120000);
 	const resources = await Promise.all(ASSETS.map(async (url) => {
-		const response = await fetch(new Request(url, { cache: "no-store" }));
+		const response = await fetch(new Request(url, { cache: "no-store", signal }));
 		if (!response.ok || response.redirected) {
 			throw new Error("资源下载失败");
 		}

assets/webui/wasm/assets.go

@@ -0,0 +1,22 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package wasmassets
+
+import "embed"
+
+// FS WebUI嵌入WASM引擎
+//
+//go:embed ofdgo.wasm
+var FS embed.FS

build.bat

@@ -0,0 +1,18 @@
+setlocal
+set Version=
+for /f %%V in ('git show -s --format^=%%ct-%%H HEAD') do set Version=%%V
+
+set GOOS=linux
+set GOARCH=arm64
+set CGO_ENABLED=0
+go build -o releases/ofdgo_linux_arm64 -trimpath -ldflags "-s -w -buildid= -X github.com/xiaoqidun/ofdgo/internal/build.Version=%Version%" ./cmd/webview
+
+set GOOS=linux
+set GOARCH=amd64
+set CGO_ENABLED=0
+go build -o releases/ofdgo_linux_amd64 -trimpath -ldflags "-s -w -buildid= -X github.com/xiaoqidun/ofdgo/internal/build.Version=%Version%" ./cmd/webview
+
+set GOOS=windows
+set GOARCH=amd64
+set CGO_ENABLED=0
+go build -o releases/ofdgo_windows_amd64.exe -trimpath -ldflags "-H windowsgui -s -w -buildid= -X github.com/xiaoqidun/ofdgo/internal/build.Version=%Version%" ./cmd/webview

cmd/webui/webui.go

@@ -18,6 +18,9 @@ package main
 
 import (
 	"bytes"
+	"crypto/sha256"
+	"embed"
+	"encoding/hex"
 	"flag"
 	"fmt"
 	"net/http"
@@ -25,6 +28,8 @@ import (
 	"time"
 
 	"github.com/xiaoqidun/ofdgo/assets/webui"
+	"github.com/xiaoqidun/ofdgo/assets/webui/wasm"
+	"github.com/xiaoqidun/ofdgo/internal/build"
 )
 
 func main() {
@@ -39,12 +44,18 @@ func main() {
 // 返回: http.Handler HTTP处理器
 func serveWebUI() http.Handler {
 	files := http.FileServerFS(webuiassets.FS)
-	checksum := webuiassets.Checksum()
+	wasm := http.FileServerFS(wasmassets.FS)
+	checksum := resourceChecksum()
 	serviceWorker, _ := webuiassets.FS.ReadFile("ofdgo_work.js")
 	serviceWorker = append([]byte(fmt.Sprintf("const BUNDLE_CHECKSUM = %q;\n", checksum)), serviceWorker...)
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Cache-Control", "no-store")
 		w.Header().Set("X-OFDGo-Checksum", checksum)
+		w.Header().Set("X-OFDGo-Build-Version", build.Version)
+		if r.URL.Path == "/ofdgo.wasm" {
+			wasm.ServeHTTP(w, r)
+			return
+		}
 		if r.URL.Path == "/ofdgo_work.js" {
 			http.ServeContent(w, r, "ofdgo_work.js", time.Time{}, bytes.NewReader(serviceWorker))
 			return
@@ -52,3 +63,17 @@ func serveWebUI() http.Handler {
 		files.ServeHTTP(w, r)
 	})
 }
+
+// resourceChecksum 计算WebUI界面与WASM引擎的资源校验值
+// 返回: string SHA-256十六进制校验值
+func resourceChecksum() string {
+	hash := sha256.New()
+	for _, resources := range []embed.FS{webuiassets.FS, wasmassets.FS} {
+		entries, _ := resources.ReadDir(".")
+		for _, entry := range entries {
+			data, _ := resources.ReadFile(entry.Name())
+			hash.Write(data)
+		}
+	}
+	return hex.EncodeToString(hash.Sum(nil))
+}

cmd/webview/webview.go

@@ -0,0 +1,59 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build (windows && amd64) || (linux && (amd64 || arm64))
+
+package main
+
+import (
+	"os"
+	"strings"
+)
+
+// commandLine 读取桌面参数并处理参数错误
+// 返回: []string 文件路径, string 浏览器数据目录
+func commandLine() ([]string, string) {
+	paths, dataDir, ok := parseArguments(os.Args[1:])
+	if !ok {
+		os.Exit(2)
+	}
+	return paths, dataDir
+}
+
+// parseArguments 解析双横线选项及后续文件路径
+// 入参: args 启动参数
+// 返回: []string 文件路径, string 浏览器数据目录, bool 参数是否有效
+func parseArguments(args []string) ([]string, string, bool) {
+	var dataDir string
+	for len(args) > 0 {
+		arg := args[0]
+		switch {
+		case arg == "--":
+			return args[1:], dataDir, true
+		case arg == "--data-dir":
+			if len(args) < 2 || strings.HasPrefix(args[1], "-") {
+				return nil, dataDir, false
+			}
+			dataDir, args = args[1], args[1:]
+		case strings.HasPrefix(arg, "--data-dir="):
+			dataDir = strings.TrimPrefix(arg, "--data-dir=")
+		case strings.HasPrefix(arg, "-"):
+			return nil, dataDir, false
+		default:
+			return args, dataDir, true
+		}
+		args = args[1:]
+	}
+	return nil, dataDir, true
+}

cmd/webview/webview_linux.go

@@ -0,0 +1,33 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build linux && (amd64 || arm64)
+
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"github.com/xiaoqidun/ofdgo/internal/webview"
+)
+
+func main() {
+	paths, dataDir := commandLine()
+	if err := webview.Run(context.Background(), paths, dataDir); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}

cmd/webview/webview_unsupported.go

@@ -0,0 +1,27 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !(windows && amd64) && !(linux && (amd64 || arm64))
+
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+func main() {
+	fmt.Fprintln(os.Stderr, "OFDGo WebView Unsupported")
+	os.Exit(1)
+}

cmd/webview/webview_windows.go

@@ -0,0 +1,38 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build windows && amd64
+
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"syscall"
+	"unsafe"
+
+	"github.com/xiaoqidun/ofdgo/internal/webview"
+)
+
+func main() {
+	paths, dataDir := commandLine()
+	if err := webview.Run(context.Background(), paths, dataDir); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		message, _ := syscall.UTF16PtrFromString(err.Error())
+		title, _ := syscall.UTF16PtrFromString("OFDGo")
+		syscall.NewLazyDLL("user32.dll").NewProc("MessageBoxW").Call(0, uintptr(unsafe.Pointer(message)), uintptr(unsafe.Pointer(title)), 0x10)
+		os.Exit(1)
+	}
+}

go.mod

@@ -3,16 +3,18 @@ module github.com/xiaoqidun/ofdgo
 go 1.26.0
 
 require (
-	github.com/emmansun/gmsm v0.45.0
-	github.com/go-fonts/latin-modern v0.3.3
+	github.com/andybalholm/brotli v1.2.7
+	github.com/emmansun/gmsm v0.45.2
 	github.com/go-text/typesetting v0.3.5
 	github.com/tdewolff/canvas v0.0.0-20260923214215-09804640d00c
-	github.com/tdewolff/font v0.0.0-20260913163313-54f98bb59ee6
-	github.com/xiaoqidun/j2kgo v0.0.0-20261009063910-4865a21ef893
-	github.com/xiaoqidun/jbig2 v1.1.4
-	github.com/xiaoqidun/pdfgo v0.0.0-20261010065159-b32618b0bdd7
+	github.com/tdewolff/font v0.0.0-20261010204837-88a7f6b56918
+	github.com/xiaoqidun/guigo v0.0.0-20261030153939-c39abf593a0f
+	github.com/xiaoqidun/j2kgo v1.0.2
+	github.com/xiaoqidun/jbig2 v1.1.8
+	github.com/xiaoqidun/pdfgo v0.0.0-20261026125713-90454771d5d0
 	golang.org/x/crypto v0.58.0
 	golang.org/x/image v0.47.0
+	golang.org/x/sys v0.49.0
 	golang.org/x/text v0.43.0
 )
 
@@ -23,9 +25,10 @@ require (
 	github.com/BurntSushi/xgb v0.0.0-20210121224620-deaf085860bc // indirect
 	github.com/BurntSushi/xgbutil v0.0.0-20190907113008-ad855c713046 // indirect
 	github.com/ByteArena/poly2tri-go v0.0.0-20170716161910-d102ad91854f // indirect
-	github.com/andybalholm/brotli v1.2.2 // indirect
 	github.com/benoitkugler/textlayout v0.3.2 // indirect
 	github.com/benoitkugler/textprocessing v0.0.6 // indirect
+	github.com/ebitengine/purego v0.11.2 // indirect
+	github.com/go-fonts/latin-modern v0.3.3 // indirect
 	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0 // indirect
 	github.com/srwiley/rasterx v0.0.0-20220730225603-2ab79fcdd4ef // indirect
 	github.com/srwiley/scanx v0.0.0-20190309010443-e94503791388 // indirect
@@ -33,7 +36,6 @@ require (
 	github.com/tdewolff/parse/v2 v2.8.16 // indirect
 	github.com/yuin/goldmark v1.8.5 // indirect
 	golang.org/x/net v0.60.0 // indirect
-	golang.org/x/sys v0.49.0 // indirect
 	modernc.org/knuth v0.6.0 // indirect
 	modernc.org/token v1.1.0 // indirect
 	star-tex.org/x/tex v0.7.1 // indirect

go.sum

@@ -20,16 +20,18 @@ github.com/ByteArena/poly2tri-go v0.0.0-20170716161910-d102ad91854f h1:l7moT9o/v
 github.com/ByteArena/poly2tri-go v0.0.0-20170716161910-d102ad91854f/go.mod h1:vIOkSdX3NDCPwgu8FIuTat2zDF0FPXXQ0RYFRy+oQic=
 github.com/ajstarks/svgo v0.0.0-20211024235047-1546f124cd8b h1:slYM766cy2nI3BwyRiyQj/Ud48djTMtMebDqepE95rw=
 github.com/ajstarks/svgo v0.0.0-20211024235047-1546f124cd8b/go.mod h1:1KcenG0jGWcpt8ov532z81sp/kMMUG485J2InIOyADM=
-github.com/andybalholm/brotli v1.2.2 h1:HzTuoo2ErYQqf5qvcJInB8uvqSVxRttzkFexPWtnceM=
-github.com/andybalholm/brotli v1.2.2/go.mod h1:rzTDkvFWvIrjDXZHkuS16NPggd91W3kUSvPlQ1pLaKY=
+github.com/andybalholm/brotli v1.2.7 h1:UgafRPGMam5ySHfRkhthMqOFA6IFoeF3D7mWIDLjG5A=
+github.com/andybalholm/brotli v1.2.7/go.mod h1:rzTDkvFWvIrjDXZHkuS16NPggd91W3kUSvPlQ1pLaKY=
 github.com/benoitkugler/pstokenizer v1.0.0/go.mod h1:l1G2Voirz0q/jj0TQfabNxVsa8HZXh/VMxFSRALWTiE=
 github.com/benoitkugler/textlayout v0.3.2 h1:Y/LTkwpQ9G0Fia9yhPmZA9IR5AnE8Cq30j3C+Gx5/IE=
 github.com/benoitkugler/textlayout v0.3.2/go.mod h1:o+1hFV+JSHBC9qNLIuwVoLedERU7sBPgEFcuSgfvi/w=
 github.com/benoitkugler/textlayout-testdata v0.1.1/go.mod h1:i/qZl09BbUOtd7Bu/W1CAubRwTWrEXWq6JwMkw8wYxo=
 github.com/benoitkugler/textprocessing v0.0.6 h1:obkMyj62GEPg3xUVYqROlCN22z1OleuZm6ULqX9Om1g=
 github.com/benoitkugler/textprocessing v0.0.6/go.mod h1:Io0gN08/PXEzrSOWFa88xHx2Xv3VjvLMY7H76YoI23A=
-github.com/emmansun/gmsm v0.45.0 h1:PU/6ObyR3g05YN3jn1L5GZDowzyAi8Xhkq4svzYNyiA=
-github.com/emmansun/gmsm v0.45.0/go.mod h1:HgLSvmdePGLo+Fo2PNgdTQU6lqAepSyriSQJRpECY6w=
+github.com/ebitengine/purego v0.11.2 h1:WWiTx8rD8zYdOwSj8O/NiNbsOvSAgJMTlyV1XlbUSeU=
+github.com/ebitengine/purego v0.11.2/go.mod h1:DCHPP08djqhNSoTfImcnHYQRZmd0qhakvrozqaEYhGQ=
+github.com/emmansun/gmsm v0.45.2 h1:GUqMkdHDrEvxqcRtIfhkyqMzgwtiQsnCVYtioOdYlQc=
+github.com/emmansun/gmsm v0.45.2/go.mod h1:RfnfrzyB9XbDi73nF1NHbJeqJj+a6pg/pXr5lrZKMok=
 github.com/go-fonts/latin-modern v0.3.3 h1:g2xNgI8yzdNzIVm+qvbMryB6yGPe0pSMss8QT3QwlJ0=
 github.com/go-fonts/latin-modern v0.3.3/go.mod h1:tHaiWDGze4EPB0Go4cLT5M3QzRY3peya09Z/8KSCrpY=
 github.com/go-text/typesetting v0.3.5 h1:XZPUooClHY0Vf/rFyUyuPRNEkawARaFzLMQcXLSEyPk=
@@ -50,20 +52,22 @@ github.com/srwiley/scanx v0.0.0-20190309010443-e94503791388 h1:ZdkidVdpLW13BQ9a+
 github.com/srwiley/scanx v0.0.0-20190309010443-e94503791388/go.mod h1:C/WY5lmWfMtPFYYBTd3Lzdn4FTLr+RxlIeiBNye+/os=
 github.com/tdewolff/canvas v0.0.0-20260923214215-09804640d00c h1:eXJXpQAo8l0AdVnsjJctG38GlBnHnwHfhLOTLYxZYNE=
 github.com/tdewolff/canvas v0.0.0-20260923214215-09804640d00c/go.mod h1:K9Ux3cwFtyAFRITZ46g7v+ORXgI3ENtQa5rL9yjNz5Y=
-github.com/tdewolff/font v0.0.0-20260913163313-54f98bb59ee6 h1:phNTWRYLLTlPpUgxkd6FDmWLlrOzpEpQAqq1ryLXYS8=
-github.com/tdewolff/font v0.0.0-20260913163313-54f98bb59ee6/go.mod h1:ipESUihcEdgRBhIwTRHmBTOMamccMQrp4iCxfa1aFws=
+github.com/tdewolff/font v0.0.0-20261010204837-88a7f6b56918 h1:z7YAbjYz/bmG0AUx2pqmClRxUI2aCxP0rQMJAMcdmok=
+github.com/tdewolff/font v0.0.0-20261010204837-88a7f6b56918/go.mod h1:ipESUihcEdgRBhIwTRHmBTOMamccMQrp4iCxfa1aFws=
 github.com/tdewolff/minify/v2 v2.24.17 h1:6AbitfVyq0M7aW6i+XL7+49DeTQZwloOMs9O574arBg=
 github.com/tdewolff/minify/v2 v2.24.17/go.mod h1:kVqn9vxXUKtlHexSNrWbYePqioOT5mc4ou/KVSMpfCM=
 github.com/tdewolff/parse/v2 v2.8.16 h1:bLk5svUOQRkW/Y2SJ+DeENSIkZBcTIkq+Atyv5D8feI=
 github.com/tdewolff/parse/v2 v2.8.16/go.mod h1:XdsoSFThlVIRIajAuqz1evNY7bagZS8LBOPA3aVopwQ=
 github.com/tdewolff/test v1.0.12 h1:7F21DqIajswxuche0geHdrUZRCWE4oko4b7bcmkkrxk=
 github.com/tdewolff/test v1.0.12/go.mod h1:XPuWBzvdUzhCuxWO1ojpXsyzsA5bFoS3tO/Q3kFuTG8=
-github.com/xiaoqidun/j2kgo v0.0.0-20261009063910-4865a21ef893 h1:jmQlBO7R+bcimOMs9jjyDWR1FqiPNGtZqA/V1WiYfPA=
-github.com/xiaoqidun/j2kgo v0.0.0-20261009063910-4865a21ef893/go.mod h1:DCwAfuDzCDYqUiAlZ7BDwigTjaXw7o9L1FtEma/D1aA=
-github.com/xiaoqidun/jbig2 v1.1.4 h1:LF6J1si4JY+TszTh9+m4KAg9/ba0JjfXoGtQTQC2S8c=
-github.com/xiaoqidun/jbig2 v1.1.4/go.mod h1:9jromqVwMqlptUDEt6Yip8vqYA5I1YjhG7FgMl/Z2dA=
-github.com/xiaoqidun/pdfgo v0.0.0-20261010065159-b32618b0bdd7 h1:VFrEkWzhLLgoMZ4FNH/uN/Mdfo/TSGKzIPjqCL4m3J4=
-github.com/xiaoqidun/pdfgo v0.0.0-20261010065159-b32618b0bdd7/go.mod h1:fXz1emtF1YCpcIv+fglDZstjkHxjS2l3G4DVMgUzVnk=
+github.com/xiaoqidun/guigo v0.0.0-20261030153939-c39abf593a0f h1:wek1tEiTjf0i5eT6w6ILJLEPwdXP+TaH3qtRBOO1xeI=
+github.com/xiaoqidun/guigo v0.0.0-20261030153939-c39abf593a0f/go.mod h1:bXz+dPMVntPIVwePTTuMXt8Q0z1YoUGuROQSsXyUEfY=
+github.com/xiaoqidun/j2kgo v1.0.2 h1:OAjjEOfaBaQzBNcj9wx+eM68UI5pewR6SzNZa1R1DIw=
+github.com/xiaoqidun/j2kgo v1.0.2/go.mod h1:DCwAfuDzCDYqUiAlZ7BDwigTjaXw7o9L1FtEma/D1aA=
+github.com/xiaoqidun/jbig2 v1.1.8 h1:dERPW7F8gs18a/DOD9gXHR3fP1Vl6KhCNsLnq5l3BIo=
+github.com/xiaoqidun/jbig2 v1.1.8/go.mod h1:9jromqVwMqlptUDEt6Yip8vqYA5I1YjhG7FgMl/Z2dA=
+github.com/xiaoqidun/pdfgo v0.0.0-20261026125713-90454771d5d0 h1:fBOCrYQedZ3ZxAlpI5bXeVs+/kWxWbVrt0iFlmTYMpU=
+github.com/xiaoqidun/pdfgo v0.0.0-20261026125713-90454771d5d0/go.mod h1:AaabzsObZ8Z76AcaWbo6swRROrJsblyIGB7HbieeJA4=
 github.com/xyproto/randomstring v1.0.5 h1:YtlWPoRdgMu3NZtP45drfy1GKoojuR7hmRcnhZqKjWU=
 github.com/xyproto/randomstring v1.0.5/go.mod h1:rgmS5DeNXLivK7YprL0pY+lTuhNQW3iGxZ18UQApw/E=
 github.com/yuin/goldmark v1.8.5 h1:r6N5afV5qj/5S4UTch8agZHJ8UxNCMwX7WjkkJam2NA=

internal/base/file/file.go

@@ -0,0 +1,232 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package file
+
+import (
+	"context"
+	"crypto/rand"
+	"errors"
+	"fmt"
+	"io"
+	"math/big"
+	"os"
+	"path/filepath"
+	"sync"
+)
+
+// ErrChanged 表示目标文件已被其他操作修改
+var ErrChanged = errors.New("file changed since opening")
+
+// ErrBusy 表示目标文件正在写入
+var ErrBusy = errors.New("file save is in progress")
+
+// activeFiles 协调当前进程内的目标写入
+var activeFiles sync.Map
+
+// Target 保存文件路径及最近确认的文件状态，可跨次写入复用
+type Target struct {
+	mu   sync.Mutex
+	name string
+	info os.FileInfo
+}
+
+// Writer 写入同目录临时文件，提交前检查取消及目标冲突
+type Writer struct {
+	mu     sync.Mutex
+	target *Target
+	file   *os.File
+	ctx    context.Context
+	err    error
+	closed bool
+}
+
+// NewTemp 创建私有输入缓存文件，调用方负责关闭和删除
+// 入参: directory 缓存目录，空值使用系统临时目录
+// 返回: *os.File 缓存文件, error 创建错误
+func NewTemp(directory string) (*os.File, error) {
+	if directory == "" {
+		directory = os.TempDir()
+	}
+	for range 100 {
+		n, err := rand.Int(rand.Reader, big.NewInt(10000000))
+		if err != nil {
+			return nil, err
+		}
+		name := filepath.Join(directory, fmt.Sprintf("ofdgo-%07d.tmp", n.Int64()))
+		file, err := os.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0600)
+		if errors.Is(err, os.ErrExist) {
+			continue
+		}
+		return file, err
+	}
+	return nil, os.ErrExist
+}
+
+// NewTarget 记录目标当前状态，允许目标尚不存在
+// 入参: name 目标路径
+// 返回: *Target 保存目标, error 路径或文件错误
+func NewTarget(name string) (*Target, error) {
+	if name == "" {
+		return nil, os.ErrInvalid
+	}
+	name, err := filepath.Abs(name)
+	if err != nil {
+		return nil, err
+	}
+	info, err := os.Lstat(name)
+	if err != nil && !errors.Is(err, os.ErrNotExist) {
+		return nil, err
+	}
+	if info != nil && !info.Mode().IsRegular() {
+		return nil, fmt.Errorf("save target is not a regular file")
+	}
+	return &Target{name: name, info: info}, nil
+}
+
+// check 检查目标是否保持最近确认的状态
+// 返回: error 文件状态错误
+func (t *Target) check() error {
+	info, err := os.Lstat(t.name)
+	if errors.Is(err, os.ErrNotExist) {
+		if t.info == nil {
+			return nil
+		}
+		return ErrChanged
+	}
+	if err != nil {
+		return err
+	}
+	if t.info == nil || !os.SameFile(t.info, info) || t.info.Size() != info.Size() || !t.info.ModTime().Equal(info.ModTime()) {
+		return ErrChanged
+	}
+	if info.Mode().Perm()&0222 == 0 {
+		return os.ErrPermission
+	}
+	return nil
+}
+
+// Begin 创建独占写入事务，调用方必须提交或终止
+// 入参: ctx 取消上下文
+// 返回: *Writer 事务, error 创建错误
+func (t *Target) Begin(ctx context.Context) (*Writer, error) {
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	if _, loaded := activeFiles.LoadOrStore(t.name, true); loaded {
+		return nil, ErrBusy
+	}
+	if err := t.check(); err != nil {
+		activeFiles.Delete(t.name)
+		return nil, err
+	}
+	for range 100 {
+		n, err := rand.Int(rand.Reader, big.NewInt(10000000))
+		if err != nil {
+			activeFiles.Delete(t.name)
+			return nil, err
+		}
+		name := fmt.Sprintf("%s.%07d.tmp", t.name, n.Int64())
+		f, err := os.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0600)
+		if errors.Is(err, os.ErrExist) {
+			continue
+		}
+		if err != nil {
+			activeFiles.Delete(t.name)
+			return nil, err
+		}
+		return &Writer{target: t, file: f, ctx: ctx}, nil
+	}
+	activeFiles.Delete(t.name)
+	return nil, os.ErrExist
+}
+
+// Write 追加数据并记录写入错误
+// 入参: data 数据
+// 返回: int 写入长度, error 写入错误
+func (w *Writer) Write(data []byte) (int, error) {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	if w.closed {
+		return 0, os.ErrClosed
+	}
+	if w.err == nil {
+		w.err = w.ctx.Err()
+	}
+	if w.err != nil {
+		return 0, w.err
+	}
+	n, err := w.file.Write(data)
+	if err == nil && n != len(data) {
+		err = io.ErrShortWrite
+	}
+	w.err = err
+	return n, err
+}
+
+// Commit 完成写入并替换目标，成功后刷新目标状态
+// 返回: error 提交错误
+func (w *Writer) Commit() error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	if w.closed {
+		return os.ErrClosed
+	}
+	w.closed = true
+	defer activeFiles.Delete(w.target.name)
+	defer os.Remove(w.file.Name())
+	w.target.mu.Lock()
+	defer w.target.mu.Unlock()
+	if err := errors.Join(w.err, w.ctx.Err(), w.target.check()); err != nil {
+		return errors.Join(err, w.file.Close())
+	}
+	if w.target.info != nil {
+		if err := w.file.Chmod(w.target.info.Mode().Perm()); err != nil {
+			return errors.Join(err, w.file.Close())
+		}
+	}
+	if err := w.file.Sync(); err != nil {
+		return errors.Join(err, w.file.Close())
+	}
+	info, err := w.file.Stat()
+	if err = errors.Join(err, w.file.Close(), w.ctx.Err()); err != nil {
+		return err
+	}
+	if err := w.target.check(); err != nil {
+		return err
+	}
+	if err := Replace(w.file.Name(), w.target.name); err != nil {
+		return err
+	}
+	w.target.info = info
+	if current, err := os.Stat(w.target.name); err == nil {
+		w.target.info = current
+	}
+	return nil
+}
+
+// Abort 丢弃临时输出，不改变目标
+// 返回: error 清理错误
+func (w *Writer) Abort() error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	if w.closed {
+		return nil
+	}
+	w.closed = true
+	defer activeFiles.Delete(w.target.name)
+	return errors.Join(w.file.Close(), os.Remove(w.file.Name()))
+}

internal/base/file/file_other.go

@@ -0,0 +1,33 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !windows
+
+package file
+
+import "os"
+
+// Open 打开文件，路径替换后已有读取句柄仍有效
+// 入参: name 文件路径
+// 返回: *os.File 文件, error 打开错误
+func Open(name string) (*os.File, error) {
+	return os.Open(name)
+}
+
+// Replace 替换目标路径
+// 入参: source 临时路径, target 目标路径
+// 返回: error 替换错误
+func Replace(source, target string) error {
+	return os.Rename(source, target)
+}

internal/base/file/file_windows.go

@@ -0,0 +1,81 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package file
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"syscall"
+	"unsafe"
+)
+
+// replaceFileProc 保留目标文件属性并替换文件内容
+var replaceFileProc = syscall.NewLazyDLL("kernel32.dll").NewProc("ReplaceFileW")
+
+// Open 保留替换共享权限，路径替换后已有读取句柄仍有效
+// 入参: name 文件路径
+// 返回: *os.File 文件, error 打开错误
+func Open(name string) (*os.File, error) {
+	path, err := nativePath(name)
+	if err != nil {
+		return nil, err
+	}
+	handle, err := syscall.CreateFile(path, syscall.GENERIC_READ, syscall.FILE_SHARE_READ|syscall.FILE_SHARE_WRITE|syscall.FILE_SHARE_DELETE, nil, syscall.OPEN_EXISTING, syscall.FILE_ATTRIBUTE_NORMAL, 0)
+	if err != nil {
+		return nil, &os.PathError{Op: "open", Path: name, Err: err}
+	}
+	return os.NewFile(uintptr(handle), name), nil
+}
+
+// Replace 替换目标，目标不存在时重命名
+// 入参: source 临时路径, target 目标路径
+// 返回: error 替换错误
+func Replace(source, target string) error {
+	from, err := nativePath(source)
+	if err != nil {
+		return err
+	}
+	to, err := nativePath(target)
+	if err != nil {
+		return err
+	}
+	result, _, err := replaceFileProc.Call(uintptr(unsafe.Pointer(to)), uintptr(unsafe.Pointer(from)), 0, 0, 0, 0)
+	if result != 0 {
+		return nil
+	}
+	if err == syscall.ERROR_FILE_NOT_FOUND {
+		return os.Rename(source, target)
+	}
+	return &os.LinkError{Op: "replace", Old: source, New: target, Err: err}
+}
+
+// nativePath 转换绝对长路径
+// 入参: name 路径
+// 返回: *uint16 原生路径, error 转换错误
+func nativePath(name string) (*uint16, error) {
+	path, err := filepath.Abs(name)
+	if err != nil {
+		return nil, err
+	}
+	if !strings.HasPrefix(path, `\\?\`) {
+		if strings.HasPrefix(path, `\\`) {
+			path = `\\?\UNC\` + path[2:]
+		} else {
+			path = `\\?\` + path
+		}
+	}
+	return syscall.UTF16PtrFromString(path)
+}

internal/base/font/cff.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package font
 
 import (
 	"bytes"
@@ -30,16 +30,16 @@ import (
 // cffDict 使用float64存储所有数值，以统一处理整数和实数
 type cffDict map[int][]float64
 
-// wrapCFFToOTF 将CFF裸数据包装为OpenType字体格式
+// WrapCFFToOTF 将CFF裸数据包装为OpenType字体格式
 // 入参: cffData CFF字体数据
 // 返回: []byte OTF字体数据, map[rune]uint16 字符映射, error 错误信息
-func wrapCFFToOTF(cffData []byte) ([]byte, map[rune]uint16, error) {
+func WrapCFFToOTF(cffData []byte) ([]byte, map[rune]uint16, error) {
 	numGlyphs, err := parseCFFAndCountGlyphs(cffData)
 	if err != nil {
 		return nil, nil, err
 	}
 	mapping := getCmapFromCFF(cffData, int(numGlyphs))
-	sanitized, err := sanitizeCFF(cffData)
+	sanitized, err := SanitizeCFF(cffData)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -70,10 +70,10 @@ func wrapCFFToOTF(cffData []byte) ([]byte, map[rune]uint16, error) {
 	tables["maxp"] = buildCFFMaxpTable(uint16(numGlyphs))
 	tables["OS/2"] = buildOS2Table()
 	tables["name"] = buildNameTable()
-	tables["post"] = buildPostTable()
+	tables["post"] = BuildPostTable()
 	tables["hmtx"] = buildHmtxTable(widths)
-	tables["cmap"] = buildCmapTable(uint16(numGlyphs), mapping)
-	data, err := serializeOTF(tables)
+	tables["cmap"] = BuildCmapTable(uint16(numGlyphs), mapping)
+	data, err := SerializeOTF(tables)
 	return data, mapping, err
 }
 
@@ -81,13 +81,13 @@ func wrapCFFToOTF(cffData []byte) ([]byte, map[rune]uint16, error) {
 // 入参: data CFF字体数据
 // 返回: []byte 标准化后的CFF数据, error 错误信息
 func normalizeCFFCharstrings(data []byte) ([]byte, error) {
-	return normalizeCFFCharstringsAt(data, 0)
+	return NormalizeCFFCharstringsAt(data, 0)
 }
 
-// normalizeCFFCharstringsAt 统一CFF设计坐标，现有OpenType字体使用head表的设计单位
+// NormalizeCFFCharstringsAt 统一CFF设计坐标，现有OpenType字体使用head表的设计单位
 // 入参: data CFF字体数据, unitsPerEm 设计单位，0时由字体矩阵确定
 // 返回: []byte 标准化后的CFF数据, error 错误信息
-func normalizeCFFCharstringsAt(data []byte, unitsPerEm uint16) ([]byte, error) {
+func NormalizeCFFCharstringsAt(data []byte, unitsPerEm uint16) ([]byte, error) {
 	if len(data) < 4 || int(data[2]) >= len(data) {
 		return nil, fmt.Errorf("invalid CFF header")
 	}
@@ -131,6 +131,14 @@ func normalizeCFFCharstringsAt(data []byte, unitsPerEm uint16) ([]byte, error) {
 	if err != nil {
 		return nil, err
 	}
+	if _, cid := dict[1230]; !cid {
+		for op := 1231; op <= 1238; op++ {
+			if _, exists := dict[op]; exists {
+				delete(dict, op)
+				changed = true
+			}
+		}
+	}
 	if transform != nil {
 		scale := 1 / float64(unitsPerEm)
 		dict[1207] = []float64{scale, 0, 0, scale, 0, 0}
@@ -214,10 +222,10 @@ func replaceCFFCharstrings(data []byte, dict cffDict, topStart, topSize, charSta
 	return result
 }
 
-// sanitizeCFF 尝试清洗CFF数据，转换CID字体并合并FontMatrix
+// SanitizeCFF 尝试清洗CFF数据，转换CID字体并合并FontMatrix
 // 入参: data 原始CFF数据
 // 返回: []byte 清洗后的CFF数据, error 错误信息
-func sanitizeCFF(data []byte) ([]byte, error) {
+func SanitizeCFF(data []byte) ([]byte, error) {
 	if !isBareCFFData(data) {
 		return nil, fmt.Errorf("invalid CFF header")
 	}
@@ -260,6 +268,21 @@ func sanitizeCFF(data []byte) ([]byte, error) {
 		if kind == 1 {
 			return normalizeCFFType1(data, topDict)
 		}
+		private, err := readType2Private(data, topDict[18], &type2Font{})
+		if err != nil {
+			return nil, err
+		}
+		count := len(private)
+		if err := normalizeCFFPrivate(private); err != nil {
+			return nil, err
+		}
+		if len(private) != count {
+			font, err := readType2Font(data)
+			if err != nil {
+				return nil, err
+			}
+			return rebuildNamedCFF(data, font, font.chars, nil)
+		}
 		return data, nil
 	}
 	fdArrOff, err := cffDictOffset(data, topDict, 1236)
@@ -316,10 +339,9 @@ func sanitizeCFF(data []byte) ([]byte, error) {
 		localSubrData = data[start:end]
 	}
 	charStringsData := data[charStringsOff:charEnd]
-	delete(topDict, 1230)
-	delete(topDict, 1236)
-	delete(topDict, 1237)
-	delete(topDict, 1234)
+	for op := 1230; op <= 1238; op++ {
+		delete(topDict, op)
+	}
 	delete(topDict, 15)
 	delete(topDict, 16)
 	var finalPrivData []byte
@@ -342,17 +364,21 @@ func sanitizeCFF(data []byte) ([]byte, error) {
 	return encodeSanitizedCFF(data[:hdrSize], nameIndexData, topDict, stringIndexData, globalSubrIndexData, charStringsData, finalPrivData, localSubrData), nil
 }
 
-// normalizeCFFPrivate 移除旧版CFF中不生效的缺省字段，拒绝需要额外解释的取值
+// normalizeCFFPrivate 移除废弃的加粗阈值及未加密标记，拒绝加密字形程序
 // 入参: dict 私有字典
 // 返回: error 不支持的旧版行为
 func normalizeCFFPrivate(dict cffDict) error {
-	for op, value := range map[int]float64{1215: 0, 1216: -1} {
-		if values, ok := dict[op]; ok {
-			if len(values) != 1 || values[0] != value {
-				return fmt.Errorf("unsupported legacy CFF private operator %d", op)
-			}
-			delete(dict, op)
+	if values, ok := dict[1215]; ok {
+		if len(values) != 1 || !finite(values[0]) {
+			return fmt.Errorf("invalid legacy CFF bold threshold")
 		}
+		delete(dict, 1215)
+	}
+	if values, ok := dict[1216]; ok {
+		if len(values) != 1 || values[0] != -1 {
+			return fmt.Errorf("unsupported legacy CFF private operator 1216")
+		}
+		delete(dict, 1216)
 	}
 	return nil
 }
@@ -397,9 +423,9 @@ func sanitizeMultiFDCFF(data []byte, hdrSize int, nameIndexData []byte, topDict
 		return nil, fmt.Errorf("invalid CFF FDArray count")
 	}
 	fonts := make([]type2Font, fdCount)
-	var type1Fonts []*type1Program
+	var type1Fonts []*Type1Program
 	if kind == 1 {
-		type1Fonts = make([]*type1Program, fdCount)
+		type1Fonts = make([]*Type1Program, fdCount)
 	}
 	privateDicts := make([]cffDict, fdCount)
 	matrices := make([][6]float64, fdCount)
@@ -475,10 +501,9 @@ func sanitizeMultiFDCFF(data []byte, hdrSize int, nameIndexData []byte, topDict
 		}
 		inlined[gid] = output.Bytes()
 	}
-	delete(topDict, 1230)
-	delete(topDict, 1236)
-	delete(topDict, 1237)
-	delete(topDict, 1234)
+	for op := 1230; op <= 1238; op++ {
+		delete(topDict, op)
+	}
 	delete(topDict, 15)
 	delete(topDict, 16)
 	delete(topDict, 1206)
@@ -602,13 +627,20 @@ func parseCFFDict(data []byte) cffDict {
 // 入参: data 字典数据
 // 返回: cffDict 字典映射, error 编码或操作数错误
 func readCFFDict(data []byte) (cffDict, error) {
+	return readCFFDictionary(data, false)
+}
+
+// readCFFDictionary 读取字体字典，CFF2顶层字典允许变化存储偏移操作符
+// 入参: data 字典数据, cff2 是否为CFF2顶层字典
+// 返回: cffDict 字典映射, error 编码或操作数错误
+func readCFFDictionary(data []byte, cff2 bool) (cffDict, error) {
 	dict := make(cffDict)
 	var operands []float64
 	i := 0
 	for i < len(data) {
 		b := data[i]
 		i++
-		if b <= 21 {
+		if b <= 21 || cff2 && b == 24 {
 			op := int(b)
 			if b == 12 {
 				if i >= len(data) {
@@ -718,7 +750,7 @@ func parseCFFReal(data []byte) (string, int) {
 	return sb.String(), i
 }
 
-// encodeCFFDict 编码CFF字典 (仅使用float64操作数)
+// encodeCFFDict 编码CFF字典，将字体类型标识置于首项
 // 入参: dict CFF字典映射
 // 返回: []byte 编码后的字典数据
 func encodeCFFDict(dict cffDict) []byte {
@@ -728,6 +760,13 @@ func encodeCFFDict(dict cffDict) []byte {
 		keys = append(keys, k)
 	}
 	sort.Ints(keys)
+	for index, op := range keys {
+		if op == 1220 || op == 1230 {
+			copy(keys[1:index+1], keys[:index])
+			keys[0] = op
+			break
+		}
+	}
 	for _, op := range keys {
 		vals := dict[op]
 		if len(vals) == 0 && (op >= 6 && op <= 9 || op == 1212 || op == 1213) {
@@ -812,10 +851,8 @@ func encodeNumberCFF(buf *bytes.Buffer, val float64) {
 // 返回: []byte 编码后的索引数据
 func encodeCFFIndex(items []([]byte)) []byte {
 	count := len(items)
-	buf := new(bytes.Buffer)
-	binary.Write(buf, binary.BigEndian, uint16(count))
 	if count == 0 {
-		return buf.Bytes()
+		return []byte{0, 0}
 	}
 	totalSize := 0
 	for _, item := range items {
@@ -831,25 +868,21 @@ func encodeCFFIndex(items []([]byte)) []byte {
 	if totalSize+1 > 16777215 {
 		offSize = 4
 	}
-	buf.WriteByte(byte(offSize))
+	base := 3 + (count+1)*offSize
+	data := make([]byte, base+totalSize)
+	binary.BigEndian.PutUint16(data, uint16(count))
+	data[2] = byte(offSize)
 	offset := 1
-	putOffset(buf, offset, offSize)
-	for _, item := range items {
-		offset += len(item)
-		putOffset(buf, offset, offSize)
+	for i := 0; i <= count; i++ {
+		for j := 0; j < offSize; j++ {
+			data[3+i*offSize+offSize-1-j] = byte(offset >> (8 * j))
+		}
+		if i < count {
+			copy(data[base+offset-1:], items[i])
+			offset += len(items[i])
+		}
 	}
-	for _, item := range items {
-		buf.Write(item)
-	}
-	return buf.Bytes()
-}
-
-// putOffset 写入指定大小的偏移量
-// 入参: buf 缓冲区, val 偏移值, size 字节大小
-func putOffset(buf *bytes.Buffer, val int, size int) {
-	tmp := make([]byte, 4)
-	binary.BigEndian.PutUint32(tmp, uint32(val))
-	buf.Write(tmp[4-size:])
+	return data
 }
 
 // getCFFIndexCount 读取CFF索引的计数和大小
@@ -1028,6 +1061,9 @@ func getCFFCharsetInfo(data []byte, numGlyphs int) ([]int, string, string, int,
 	if topDictData == nil {
 		return nil, "", "", 0, false
 	}
+	if _, _, _, err := scanCFFIndex(data, stringIndexOff); err != nil {
+		return nil, "", "", 0, false
+	}
 	td := parseCFFDict(topDictData)
 	registry, ordering := getCFFROS(data, stringIndexOff, td)
 	actual, err := parseCFFAndCountGlyphs(data)
@@ -1059,13 +1095,24 @@ func getCmapFromCFF(data []byte, numGlyphs int) map[rune]uint16 {
 	if !ok {
 		return nil
 	}
-	mapping := make(map[rune]uint16)
+	return cffCharsetMapping(data, sids, registry, ordering, stringIndexOff)
+}
+
+// cffCharsetMapping 根据已解析的CFF字符集恢复Unicode映射
+// 入参: data CFF数据, sids 字符标识, registry 注册机构, ordering 字符集, stringIndexOff 字符串索引偏移
+// 返回: map[rune]uint16 恢复的映射表
+func cffCharsetMapping(data []byte, sids []int, registry, ordering string, stringIndexOff int) map[rune]uint16 {
+	capacity := max(0, len(sids)-1)
+	if registry == "" || registry == "Adobe" && ordering == "GB1" {
+		capacity *= 2
+	}
+	mapping := make(map[rune]uint16, capacity)
 	if registry == "Adobe" && ordering == "GB1" {
 		for gid, cid := range sids {
 			if gid == 0 {
 				continue
 			}
-			mapping[packedGlyphRune(uint16(gid))] = uint16(gid)
+			mapping[PackedGlyphRune(uint16(gid))] = uint16(gid)
 			if r, ok := adobeGB1CIDToUnicode(cid); ok {
 				mapping[r] = uint16(gid)
 			}
@@ -1077,7 +1124,7 @@ func getCmapFromCFF(data []byte, numGlyphs int) map[rune]uint16 {
 			if gid == 0 {
 				continue
 			}
-			mapping[packedGlyphRune(uint16(gid))] = uint16(gid)
+			mapping[PackedGlyphRune(uint16(gid))] = uint16(gid)
 		}
 		return mapping
 	}
@@ -1092,25 +1139,25 @@ func getCmapFromCFF(data []byte, numGlyphs int) map[rune]uint16 {
 			}
 		} else {
 			idx := sid - 391
-			name = readStringIndexItem(data, stringIndexOff, idx)
+			name = string(readStringIndexItem(data, stringIndexOff, idx))
 		}
 		r := rune(0)
 		if name != "" {
 			r = getUnicodeFromName(name)
 		}
 		if r == 0 {
-			r = packedGlyphRune(uint16(gid))
+			r = PackedGlyphRune(uint16(gid))
 		}
-		mapping[packedGlyphRune(uint16(gid))] = uint16(gid)
+		mapping[PackedGlyphRune(uint16(gid))] = uint16(gid)
 		mapping[r] = uint16(gid)
 	}
 	return mapping
 }
 
-// getCFFCIDRuneMap 获取CID到包装字体字符的映射
+// GetCFFCIDRuneMap 获取CID到包装字体字符的映射
 // 入参: data CFF或OpenType字体数据
 // 返回: map[uint16]rune CID映射
-func getCFFCIDRuneMap(data []byte) map[uint16]rune {
+func GetCFFCIDRuneMap(data []byte) map[uint16]rune {
 	cffData := getCFFData(data)
 	if cffData == nil {
 		return nil
@@ -1119,17 +1166,17 @@ func getCFFCIDRuneMap(data []byte) map[uint16]rune {
 	if err != nil {
 		return nil
 	}
-	sids, registry, _, _, ok := getCFFCharsetInfo(cffData, numGlyphs)
+	sids, registry, ordering, stringIndexOff, ok := getCFFCharsetInfo(cffData, numGlyphs)
 	if !ok || registry == "" {
 		return nil
 	}
-	mapping := getCmapFromCFF(cffData, numGlyphs)
+	mapping := cffCharsetMapping(cffData, sids, registry, ordering, stringIndexOff)
 	if len(mapping) == 0 {
 		return nil
 	}
 	gidRunes := make(map[uint16]rune)
 	for run, gid := range mapping {
-		if run != packedGlyphRune(gid) {
+		if run != PackedGlyphRune(gid) {
 			gidRunes[gid] = run
 		}
 	}
@@ -1179,7 +1226,7 @@ func getCFFData(data []byte) []byte {
 		}
 		offset := int(binary.BigEndian.Uint32(data[pos+8 : pos+12]))
 		length := int(binary.BigEndian.Uint32(data[pos+12 : pos+16]))
-		if offset < 0 || length < 0 || offset+length > len(data) {
+		if offset < 0 || length < 0 || offset > len(data) || length > len(data)-offset {
 			return nil
 		}
 		return data[offset : offset+length]
@@ -1261,31 +1308,29 @@ func parseCFFCharset(data []byte, offset, count int) ([]int, error) {
 
 // readStringIndexItem 读取CFF字符串索引项
 // 入参: data CFF数据, offset 索引偏移, idx 索引号
-// 返回: string 读取的字符串
-func readStringIndexItem(data []byte, offset int, idx int) string {
-	if offset >= len(data) {
-		return ""
+// 返回: []byte 共享原始数据的只读字符串，索引无效时为nil
+func readStringIndexItem(data []byte, offset int, idx int) []byte {
+	if offset < 0 || offset > len(data)-2 || idx < 0 {
+		return nil
 	}
 	count := int(binary.BigEndian.Uint16(data[offset:]))
+	if idx >= count || offset > len(data)-3 {
+		return nil
+	}
 	offSize := int(data[offset+2])
-	if idx >= count {
-		return ""
+	if offSize < 1 || offSize > 4 || count+1 > (len(data)-offset-3)/offSize {
+		return nil
 	}
 	offArrayStart := offset + 3
 	p1 := offArrayStart + idx*offSize
 	p2 := p1 + offSize
-	if p2+offSize > len(data) {
-		return ""
-	}
 	loc1 := readCFFOffset(data, p1, offSize)
 	loc2 := readCFFOffset(data, p2, offSize)
 	dataStart := offArrayStart + (count+1)*offSize
-	start := dataStart + loc1 - 1
-	length := loc2 - loc1
-	if start < 0 || start+length > len(data) {
-		return ""
+	if loc1 < 1 || loc2 < loc1 || loc2-1 > len(data)-dataStart {
+		return nil
 	}
-	return string(data[start : start+length])
+	return data[dataStart+loc1-1 : dataStart+loc2-1]
 }
 
 // getCFFROS 读取CID字体ROS信息
@@ -1309,7 +1354,7 @@ func getCFFSIDString(data []byte, stringIndexOff int, sid int) string {
 		return cffStandardStrings[sid]
 	}
 	if sid > 390 {
-		return readStringIndexItem(data, stringIndexOff, sid-391)
+		return string(readStringIndexItem(data, stringIndexOff, sid-391))
 	}
 	return ""
 }
@@ -1341,16 +1386,17 @@ func adobeGB1CIDToUnicode(cid int) (rune, bool) {
 	if row < 16 || row > 87 || cell < 1 || cell > 94 {
 		return 0, false
 	}
-	gbk := []byte{byte(row + 0xA0), byte(cell + 0xA0)}
-	decoded, err := simplifiedchinese.GBK.NewDecoder().Bytes(gbk)
-	if err != nil || len(decoded) == 0 {
+	gbk := [2]byte{byte(row + 0xA0), byte(cell + 0xA0)}
+	var decoded [2 * utf8.UTFMax]byte
+	nDst, nSrc, err := simplifiedchinese.GBK.NewDecoder().Transform(decoded[:], gbk[:], true)
+	if err != nil || nDst == 0 || nSrc != len(gbk) {
 		return 0, false
 	}
-	rs := []rune(string(decoded))
-	if len(rs) != 1 {
+	r, size := utf8.DecodeRune(decoded[:nDst])
+	if size != nDst {
 		return 0, false
 	}
-	return rs[0], true
+	return r, true
 }
 
 // getUnicodeFromName 根据字形名称获取对应的Unicode字符

internal/base/font/cff2.go

@@ -0,0 +1,205 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package font
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"math"
+
+	"github.com/go-text/typesetting/font/cff"
+	"github.com/go-text/typesetting/font/opentype"
+	"github.com/go-text/typesetting/font/opentype/tables"
+)
+
+// DefaultCFF2Font 将CFF2默认实例转换为静态OpenType字体，保留字形编号和三次轮廓
+// 入参: data 独立字体数据
+// 返回: []byte 字体数据，非CFF2原样返回, error 解析或编码错误
+func DefaultCFF2Font(data []byte) (result []byte, err error) {
+	if len(data) < 12 || string(data[:4]) != "OTTO" {
+		return data, nil
+	}
+	found := false
+	for i, count := 0, int(binary.BigEndian.Uint16(data[4:])); i < count && i < (len(data)-12)/16; i++ {
+		if string(data[12+i*16:16+i*16]) == "CFF2" {
+			found = true
+			break
+		}
+	}
+	if !found {
+		return data, nil
+	}
+	table, err := FileTables(data, 0)
+	if err != nil || table["CFF2"] == nil {
+		return data, err
+	}
+	if table["CFF "] != nil || table["glyf"] != nil || len(table["head"]) < 54 || len(table["maxp"]) < 6 || len(table["hhea"]) < 36 {
+		return nil, fmt.Errorf("invalid CFF2 font tables")
+	}
+	defer func() {
+		if failure := recover(); failure != nil {
+			result, err = nil, fmt.Errorf("invalid CFF2 font: %v", failure)
+		}
+	}()
+	cffData := table["CFF2"]
+	if len(cffData) < 5 || cffData[0] != 2 || cffData[1] != 0 || cffData[2] < 5 || binary.BigEndian.Uint32(table["maxp"]) != 0x5000 {
+		return nil, fmt.Errorf("invalid CFF2 header")
+	}
+	start := int(cffData[2])
+	end := start + int(binary.BigEndian.Uint16(cffData[3:]))
+	if end > len(cffData) {
+		return nil, fmt.Errorf("invalid CFF2 dictionary length")
+	}
+	dict, err := readCFFDictionary(cffData[start:end], true)
+	if err != nil {
+		return nil, err
+	}
+	matrix, err := readCFFMatrix(dict, [6]float64{.001, 0, 0, .001, 0, 0})
+	units := binary.BigEndian.Uint16(table["head"][18:])
+	if err != nil || units < 16 || units > 16384 || matrix[0] != matrix[3] || matrix[1] != 0 || matrix[2] != 0 || matrix[4] != 0 || matrix[5] != 0 || math.Abs(matrix[0]*float64(units)-1) > 1e-6 {
+		return nil, fmt.Errorf("CFF2 FontMatrix does not match design units")
+	}
+	program, err := cff.ParseCFF2(table["CFF2"])
+	if err != nil {
+		return nil, err
+	}
+	if len(dict[24]) != 0 {
+		fvar := table["fvar"]
+		if len(fvar) < 16 || binary.BigEndian.Uint32(fvar) != 0x10000 || int(binary.BigEndian.Uint16(fvar[8:])) != program.VarStore.AxisCount() {
+			return nil, fmt.Errorf("CFF2 variation axis count mismatch")
+		}
+	}
+	count := int(binary.BigEndian.Uint16(table["maxp"][4:]))
+	metrics := int(binary.BigEndian.Uint16(table["hhea"][34:]))
+	if count == 0 || len(program.Charstrings) != count || metrics == 0 || metrics > count || len(table["hmtx"]) < metrics*4+(count-metrics)*2 {
+		return nil, fmt.Errorf("invalid CFF2 glyph metrics")
+	}
+	chars := make([][]byte, count)
+	for gid := range chars {
+		segments, _, err := program.LoadGlyph(tables.GlyphID(gid), nil)
+		if err != nil {
+			return nil, fmt.Errorf("CFF2 glyph %d: %w", gid, err)
+		}
+		width := binary.BigEndian.Uint16(table["hmtx"][min(gid, metrics-1)*4:])
+		chars[gid], err = cffOutlineProgram(segments, width)
+		if err != nil {
+			return nil, fmt.Errorf("CFF2 glyph %d: %w", gid, err)
+		}
+	}
+	table["CFF "], err = staticCIDFont(table, chars)
+	if err != nil {
+		return nil, err
+	}
+	for _, tag := range []string{"CFF2", "fvar", "avar", "STAT", "HVAR", "VVAR", "MVAR", "DSIG"} {
+		delete(table, tag)
+	}
+	return SerializeOTF(table)
+}
+
+// cffOutlineProgram 将默认设计轮廓编码为无子程序的Type2字形
+// 入参: segments 字体设计坐标路径, width 水平字宽
+// 返回: []byte 字形程序, error 坐标超出编码范围
+func cffOutlineProgram(segments []opentype.Segment, width uint16) ([]byte, error) {
+	var output bytes.Buffer
+	if width < 32768 {
+		if err := encodeType2Number(&output, float64(width)); err != nil {
+			return nil, err
+		}
+	} else {
+		for range 2 {
+			if err := encodeType2Number(&output, float64(width)/2); err != nil {
+				return nil, err
+			}
+		}
+		output.Write([]byte{12, 10})
+	}
+	var x, y float64
+	for _, segment := range segments {
+		count, op := 1, byte(21)
+		switch segment.Op {
+		case opentype.SegmentOpMoveTo:
+		case opentype.SegmentOpLineTo:
+			op = 5
+		case opentype.SegmentOpCubeTo:
+			count, op = 3, 8
+		default:
+			return nil, fmt.Errorf("invalid CFF2 path operation")
+		}
+		for _, point := range segment.Args[:count] {
+			nx, ny := float64(point.X), float64(point.Y)
+			if err := encodeType2Number(&output, nx-x); err != nil {
+				return nil, err
+			}
+			if err := encodeType2Number(&output, ny-y); err != nil {
+				return nil, err
+			}
+			x, y = nx, ny
+		}
+		output.WriteByte(op)
+	}
+	output.WriteByte(14)
+	return output.Bytes(), nil
+}
+
+// staticCIDFont 封装独立Type2字形，CID与字形编号一致，不依赖字形名称
+// 入参: table OpenType表, chars 字形程序
+// 返回: []byte CFF字体, error 字体结构错误
+func staticCIDFont(table map[string][]byte, chars [][]byte) ([]byte, error) {
+	if len(chars) == 0 || len(chars) > 65535 || len(table["head"]) < 54 {
+		return nil, fmt.Errorf("invalid static CFF glyph count")
+	}
+	units := binary.BigEndian.Uint16(table["head"][18:])
+	if units < 16 || units > 16384 {
+		return nil, fmt.Errorf("invalid CFF design units")
+	}
+	name := FaceInfo(table["name"], 0).PostScriptName
+	if name == "" {
+		name = "OpenTypeInstance"
+	}
+	names := encodeCFFIndex([][]byte{[]byte(name)})
+	strings := encodeCFFIndex([][]byte{[]byte("Adobe"), []byte("Identity")})
+	cids := make([]int, len(chars))
+	for gid := 1; gid < len(chars); gid++ {
+		cids[gid] = gid
+	}
+	charset := encodeCFFSubsetCharset(cids)
+	selects := []byte{3, 0, 1, 0, 0, 0}
+	selects = binary.BigEndian.AppendUint16(selects, uint16(len(chars)))
+	fonts := encodeCFFIndex([][]byte{encodeCFFDict(cffDict{18: {0, 0}})})
+	charIndex := encodeCFFIndex(chars)
+	scale := 1 / float64(units)
+	dict := cffDict{1230: {391, 392, 0}, 1234: {float64(len(chars))}, 1207: {scale, 0, 0, scale, 0, 0}, 15: {0}, 17: {0}, 1236: {0}, 1237: {0}}
+	for i := 0; i < 4; i++ {
+		dict[5] = append(dict[5], float64(int16(binary.BigEndian.Uint16(table["head"][36+2*i:]))))
+	}
+	var top []byte
+	for range 16 {
+		top = encodeCFFIndex([][]byte{encodeCFFDict(dict)})
+		offset := 4 + len(names) + len(top) + len(strings) + 2
+		if dict[15][0] == float64(offset) {
+			var output bytes.Buffer
+			for _, part := range [][]byte{{1, 0, 4, 4}, names, top, strings, {0, 0}, charset, selects, fonts, charIndex} {
+				output.Write(part)
+			}
+			return output.Bytes(), nil
+		}
+		dict[15][0] = float64(offset)
+		dict[1237][0] = float64(offset + len(charset))
+		dict[1236][0] = float64(offset + len(charset) + len(selects))
+		dict[17][0] = float64(offset + len(charset) + len(selects) + len(fonts))
+	}
+	return nil, fmt.Errorf("CFF offsets did not converge")
+}

internal/base/font/cff_cid_subset.go

@@ -0,0 +1,239 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package font
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"math"
+)
+
+// cidSubsetFont 保存CID字体裁剪所需的字典、映射和执行资源
+type cidSubsetFont struct {
+	prefix  []byte
+	strings [][]byte
+	top     cffDict
+	dicts   []cffDict
+	private []cffDict
+	fonts   []*type2Font
+	selects []int
+	charset []byte
+}
+
+// readCIDSubsetFont 读取CID字体的原始字典及逐字形归属，不合并字体字典
+// 入参: data CFF数据
+// 返回: *cidSubsetFont 裁剪资源, error 结构错误或不支持的字典
+func readCIDSubsetFont(data []byte) (*cidSubsetFont, error) {
+	if !isBareCFFData(data) {
+		return nil, fmt.Errorf("invalid CFF header")
+	}
+	names, end, err := readType2Index(data, int(data[2]))
+	if err != nil || len(names) != 1 {
+		return nil, fmt.Errorf("invalid CFF name index")
+	}
+	tops, end, err := readType2Index(data, end)
+	if err != nil || len(tops) != 1 {
+		return nil, fmt.Errorf("invalid CFF top index")
+	}
+	strings, end, err := readType2Index(data, end)
+	if err != nil {
+		return nil, err
+	}
+	globals, _, err := readType2Index(data, end)
+	if err != nil {
+		return nil, err
+	}
+	top, err := readCFFDict(tops[0])
+	if err != nil {
+		return nil, err
+	}
+	ros := top[1230]
+	if len(ros) != 3 {
+		return nil, fmt.Errorf("invalid CFF ROS")
+	}
+	for index, value := range ros {
+		limit := float64(math.MaxInt32)
+		if index < 2 {
+			limit = float64(min(64999, 390+len(strings)))
+		}
+		if !finite(value) || value < 0 || value > limit || value != math.Trunc(value) {
+			return nil, fmt.Errorf("invalid CFF ROS operand")
+		}
+	}
+	for op := range top {
+		switch op {
+		case 0, 1, 2, 3, 4, 5, 13, 14, 15, 17, 1200, 1201, 1202, 1203, 1204, 1205, 1206, 1207, 1208, 1230, 1231, 1232, 1233, 1234, 1236, 1237:
+		default:
+			return nil, fmt.Errorf("unsupported CID CFF top operator %d", op)
+		}
+	}
+	if value, ok := top[1206]; ok && (len(value) != 1 || value[0] != 2) {
+		return nil, fmt.Errorf("unsupported CFF charstring type")
+	}
+	if _, err := readCFFMatrix(top, [6]float64{.001, 0, 0, .001, 0, 0}); err != nil {
+		return nil, err
+	}
+	charOffset, err := cffDictOffset(data, top, 17)
+	if err != nil {
+		return nil, err
+	}
+	chars, _, err := readType2Index(data, charOffset)
+	if err != nil || len(chars) == 0 {
+		return nil, fmt.Errorf("invalid CFF charstrings")
+	}
+	charsetOffset, err := cffDictOffset(data, top, 15)
+	if err != nil || charsetOffset <= 2 {
+		return nil, fmt.Errorf("invalid CID CFF charset offset")
+	}
+	cids, err := parseCFFCharset(data, charsetOffset, len(chars))
+	if err != nil {
+		return nil, err
+	}
+	fdOffset, err := cffDictOffset(data, top, 1236)
+	if err != nil {
+		return nil, err
+	}
+	fds, _, err := readType2Index(data, fdOffset)
+	if err != nil || len(fds) == 0 || len(fds) > 256 {
+		return nil, fmt.Errorf("invalid CFF font dictionary count")
+	}
+	selectOffset, err := cffDictOffset(data, top, 1237)
+	if err != nil {
+		return nil, err
+	}
+	selects, err := readType2FDSelect(data, selectOffset, len(chars), len(fds))
+	if err != nil {
+		return nil, err
+	}
+	if data[selectOffset] == 3 && binary.BigEndian.Uint16(data[selectOffset+3:]) != 0 {
+		return nil, fmt.Errorf("CFF FDSelect must include glyph zero")
+	}
+	font := &cidSubsetFont{
+		prefix:  append(bytes.Clone(data[:int(data[2])]), encodeCFFIndex(names)...),
+		strings: strings, top: top, selects: selects, charset: encodeCFFSubsetCharset(cids),
+		dicts: make([]cffDict, len(fds)), private: make([]cffDict, len(fds)), fonts: make([]*type2Font, len(fds)),
+	}
+	for index, fd := range fds {
+		dict, err := readCFFDict(fd)
+		if err != nil {
+			return nil, err
+		}
+		for op := range dict {
+			switch op {
+			case 18, 1207, 1238:
+			default:
+				return nil, fmt.Errorf("unsupported CFF font dictionary operator %d", op)
+			}
+		}
+		if _, err := readCFFMatrix(dict, [6]float64{1, 0, 0, 1, 0, 0}); err != nil {
+			return nil, err
+		}
+		if len(dict[18]) != 2 {
+			return nil, fmt.Errorf("missing CFF private dictionary")
+		}
+		resource := &type2Font{data: data, chars: chars, globals: globals, seed: 1, cid: true}
+		private, err := readType2Private(data, dict[18], resource)
+		if err != nil {
+			return nil, err
+		}
+		if _, err := encodeCFFSubsetPrivate(private); err != nil {
+			return nil, err
+		}
+		font.dicts[index], font.private[index], font.fonts[index] = dict, private, resource
+	}
+	return font, nil
+}
+
+// write 重建CID字体偏移，保留CID映射、字体矩阵及各字典的私有参数
+// 入参: chars 裁剪后的字形程序
+// 返回: []byte CFF数据, error 偏移或字典错误
+func (f *cidSubsetFont) write(chars [][]byte) ([]byte, error) {
+	suffix := append(encodeCFFIndex(f.strings), encodeCFFIndex(f.fonts[0].globals)...)
+	selects := encodeCFFSubsetFDSelect(f.selects)
+	programs := encodeCFFIndex(chars)
+	private := make([][]byte, len(f.fonts))
+	locals := make([][]byte, len(f.fonts))
+	fds := make([][]byte, len(f.fonts))
+	for index, font := range f.fonts {
+		var err error
+		private[index], err = encodeCFFSubsetPrivate(f.private[index])
+		if err != nil {
+			return nil, err
+		}
+		if _, ok := f.private[index][19]; ok {
+			locals[index] = encodeCFFIndex(font.locals)
+		}
+		fds[index] = encodeCFFDict(f.dicts[index])
+	}
+	for range 16 {
+		top := encodeCFFIndex([][]byte{encodeCFFDict(f.top)})
+		array := encodeCFFIndex(fds)
+		offset := len(f.prefix) + len(top) + len(suffix)
+		f.top[15] = []float64{float64(offset)}
+		offset += len(f.charset)
+		f.top[1237] = []float64{float64(offset)}
+		offset += len(selects)
+		f.top[17] = []float64{float64(offset)}
+		offset += len(programs)
+		f.top[1236] = []float64{float64(offset)}
+		offset += len(array)
+		for index := range f.fonts {
+			f.dicts[index][18] = []float64{float64(len(private[index])), float64(offset)}
+			fds[index] = encodeCFFDict(f.dicts[index])
+			offset += len(private[index]) + len(locals[index])
+		}
+		updatedTop := encodeCFFIndex([][]byte{encodeCFFDict(f.top)})
+		updatedArray := encodeCFFIndex(fds)
+		if len(updatedTop) != len(top) || len(updatedArray) != len(array) {
+			continue
+		}
+		result := make([]byte, 0, offset)
+		for _, part := range [][]byte{f.prefix, updatedTop, suffix, f.charset, selects, programs, updatedArray} {
+			result = append(result, part...)
+		}
+		for index := range f.fonts {
+			result = append(result, private[index]...)
+			result = append(result, locals[index]...)
+		}
+		return result, nil
+	}
+	return nil, fmt.Errorf("CID CFF offsets did not converge")
+}
+
+// encodeCFFSubsetFDSelect 选择较短的逐字形或分段格式保存字体字典归属
+// 入参: selects 字形所属字典
+// 返回: []byte FDSelect数据
+func encodeCFFSubsetFDSelect(selects []int) []byte {
+	ranges := []byte{3, 0, 0}
+	count := 0
+	for gid, fd := range selects {
+		if gid == 0 || fd != selects[gid-1] {
+			ranges = binary.BigEndian.AppendUint16(ranges, uint16(gid))
+			ranges = append(ranges, byte(fd))
+			count++
+		}
+	}
+	binary.BigEndian.PutUint16(ranges[1:], uint16(count))
+	ranges = binary.BigEndian.AppendUint16(ranges, uint16(len(selects)))
+	if len(ranges) < len(selects)+1 {
+		return ranges
+	}
+	result := make([]byte, len(selects)+1)
+	for gid, fd := range selects {
+		result[gid+1] = byte(fd)
+	}
+	return result
+}

internal/base/font/cff_compact.go

@@ -0,0 +1,339 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package font
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"slices"
+)
+
+// compactCFFGlyphs 重排已裁剪字体的字形，同步字符集、编码和字体字典归属
+// 入参: data 已裁剪的CFF数据, keep 保留的原字形编号
+// 返回: []byte 紧凑CFF数据, []uint16 新编号对应的原编号, error 结构或编码错误
+func compactCFFGlyphs(data []byte, keep map[uint16]bool) ([]byte, []uint16, error) {
+	ids := []uint16{0}
+	for gid, used := range keep {
+		if used && gid != 0 {
+			ids = append(ids, gid)
+		}
+	}
+	slices.Sort(ids)
+	font, err := readType2Font(data)
+	if err == nil {
+		sids, _, _, _, ok := getCFFCharsetInfo(data, len(font.chars))
+		if !ok {
+			return nil, nil, fmt.Errorf("invalid CFF charset")
+		}
+		_, end, _ := readType2Index(data, int(data[2]))
+		tops, _, _ := readType2Index(data, end)
+		dict, _ := readCFFDict(tops[0])
+		encoding, err := cffSubsetEncoding(data, dict)
+		if err != nil {
+			return nil, nil, err
+		}
+		if encoding != nil {
+			codes, err := readCFFSubsetEncoding(encoding, sids)
+			if err != nil {
+				return nil, nil, err
+			}
+			ordered := []uint16{0}
+			seen := map[uint16]bool{0: true}
+			for _, gid := range codes {
+				if keep[gid] && !seen[gid] {
+					ordered = append(ordered, gid)
+					seen[gid] = true
+				}
+			}
+			for _, gid := range ids {
+				if !seen[gid] {
+					ordered = append(ordered, gid)
+				}
+			}
+			ids = ordered
+		}
+		chars := make([][]byte, len(ids))
+		for index, gid := range ids {
+			if int(gid) >= len(font.chars) {
+				return nil, nil, fmt.Errorf("CFF glyph index out of range")
+			}
+			chars[index] = font.chars[gid]
+		}
+		result, err := rebuildNamedCFF(data, font, chars, ids)
+		return result, ids, err
+	}
+	cid, err := readCIDSubsetFont(data)
+	if err != nil {
+		return nil, nil, err
+	}
+	cids, _, _, _, ok := getCFFCharsetInfo(data, len(cid.selects))
+	if !ok {
+		return nil, nil, fmt.Errorf("invalid CID CFF charset")
+	}
+	chars := make([][]byte, len(ids))
+	selected := make([]int, len(ids))
+	selects := make([]int, len(ids))
+	dicts, private, fonts := []cffDict{}, []cffDict{}, []*type2Font{}
+	remap := make(map[int]int)
+	for index, gid := range ids {
+		if int(gid) >= len(cid.selects) {
+			return nil, nil, fmt.Errorf("CFF glyph index out of range")
+		}
+		fd := cid.selects[gid]
+		mapped, exists := remap[fd]
+		if !exists {
+			mapped = len(fonts)
+			remap[fd] = mapped
+			dicts = append(dicts, cid.dicts[fd])
+			private = append(private, cid.private[fd])
+			fonts = append(fonts, cid.fonts[fd])
+		}
+		chars[index], selected[index], selects[index] = cid.fonts[fd].chars[gid], cids[gid], mapped
+	}
+	cid.dicts, cid.private, cid.fonts = dicts, private, fonts
+	cid.charset, cid.selects = encodeCFFSubsetCharset(selected), selects
+	result, err := cid.write(chars)
+	return result, ids, err
+}
+
+// compactCFFTables 重建按字形编号索引的度量和字符映射，不保留旧编号的布局表
+// 入参: font 原字体, cff 紧凑CFF数据, ids 新编号对应的原编号
+// 返回: []byte 独立OpenType字体, error 封装错误
+func compactCFFTables(font *SFNT, cff []byte, ids []uint16) ([]byte, error) {
+	tables := make(map[string][]byte)
+	for _, tag := range []string{"head", "hhea", "maxp", "OS/2", "post", "name", "vhea", "gasp"} {
+		if data := font.Tables[tag]; data != nil {
+			tables[tag] = bytes.Clone(data)
+		}
+	}
+	var hmtx, vmtx []byte
+	mapping := make(map[rune]uint16)
+	for index, gid := range ids {
+		hmtx = binary.BigEndian.AppendUint16(hmtx, font.GlyphAdvance(gid))
+		hmtx = binary.BigEndian.AppendUint16(hmtx, uint16(font.sideBearing(gid, false)))
+		if font.vertical != 0 {
+			vmtx = binary.BigEndian.AppendUint16(vmtx, font.GlyphVerticalAdvance(gid))
+			vmtx = binary.BigEndian.AppendUint16(vmtx, uint16(font.sideBearing(gid, true)))
+		}
+		for _, char := range font.glyphCharacters(gid) {
+			mapping[char] = uint16(index)
+		}
+	}
+	tables["CFF "], tables["hmtx"] = cff, hmtx
+	tables["cmap"] = BuildCmapTable(uint16(len(ids)), mapping)
+	binary.BigEndian.PutUint16(tables["hhea"][34:], uint16(len(ids)))
+	binary.BigEndian.PutUint16(tables["maxp"][4:], uint16(len(ids)))
+	if len(tables["post"]) >= 32 {
+		tables["post"] = tables["post"][:32]
+		binary.BigEndian.PutUint32(tables["post"], 0x30000)
+	}
+	if font.vertical != 0 {
+		tables["vmtx"] = vmtx
+		binary.BigEndian.PutUint16(tables["vhea"][34:], uint16(len(ids)))
+	}
+	if data := font.Tables["VORG"]; data != nil {
+		var err error
+		tables["VORG"], err = compactCFFVerticalOrigins(data, font.NumGlyphs(), ids)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return SerializeOTF(tables)
+}
+
+// compactCFFVerticalOrigins 重排CFF字体的逐字形纵向原点，保留默认原点
+// 入参: data VORG表, count 原字形数, ids 新编号对应的原编号
+// 返回: []byte 重建的VORG表, error 表结构或记录顺序错误
+func compactCFFVerticalOrigins(data []byte, count uint16, ids []uint16) ([]byte, error) {
+	if len(data) < 8 || binary.BigEndian.Uint32(data) != 0x10000 {
+		return nil, fmt.Errorf("invalid CFF vertical origin header")
+	}
+	length := int(binary.BigEndian.Uint16(data[6:]))
+	if length > (len(data)-8)/4 {
+		return nil, fmt.Errorf("truncated CFF vertical origins")
+	}
+	origins := make(map[uint16]uint16, length)
+	previous := -1
+	for index := range length {
+		pos := 8 + index*4
+		gid := binary.BigEndian.Uint16(data[pos:])
+		if gid >= count || int(gid) <= previous {
+			return nil, fmt.Errorf("invalid CFF vertical origin glyph")
+		}
+		origins[gid] = binary.BigEndian.Uint16(data[pos+2:])
+		previous = int(gid)
+	}
+	result := bytes.Clone(data[:8])
+	for index, gid := range ids {
+		if origin, ok := origins[gid]; ok {
+			result = binary.BigEndian.AppendUint16(result, uint16(index))
+			result = binary.BigEndian.AppendUint16(result, origin)
+		}
+	}
+	binary.BigEndian.PutUint16(result[6:], uint16((len(result)-8)/4))
+	return result, nil
+}
+
+// encodeCFFSubsetCharset 选择最短的标准字符集格式，保持SID或CID及字形顺序
+// 入参: ids 按字形编号排列的SID或CID，包含.notdef
+// 返回: []byte 字符集数据
+func encodeCFFSubsetCharset(ids []int) []byte {
+	sizes := [3]int{1 + 2*(len(ids)-1), 1, 1}
+	for first := 1; first < len(ids); {
+		end := first + 1
+		for end < len(ids) && ids[end] == ids[end-1]+1 {
+			end++
+		}
+		sizes[1] += 3 * ((end - first + 255) / 256)
+		sizes[2] += 4
+		first = end
+	}
+	format := 0
+	for index, size := range sizes {
+		if size < sizes[format] {
+			format = index
+		}
+	}
+	result := make([]byte, 1, sizes[format])
+	result[0] = byte(format)
+	for first := 1; first < len(ids); {
+		end := first + 1
+		if format != 0 {
+			limit := len(ids)
+			if format == 1 {
+				limit = min(limit, first+256)
+			}
+			for end < limit && ids[end] == ids[end-1]+1 {
+				end++
+			}
+		}
+		result = binary.BigEndian.AppendUint16(result, uint16(ids[first]))
+		if format == 1 {
+			result = append(result, byte(end-first-1))
+		} else if format == 2 {
+			result = binary.BigEndian.AppendUint16(result, uint16(end-first-1))
+		}
+		first = end
+	}
+	return result
+}
+
+// readCFFSubsetEncoding 解析自定义编码及补充映射，校验重复编码和字形归属
+// 入参: data 编码数据, sids 原字符集
+// 返回: [256]uint16 编码对应的字形编号, error 编码结构错误
+func readCFFSubsetEncoding(data []byte, sids []int) ([256]uint16, error) {
+	var codes [256]uint16
+	if len(data) < 2 {
+		return codes, fmt.Errorf("truncated CFF encoding")
+	}
+	pos, gid := 2, 1
+	for index := 0; index < int(data[1]); index++ {
+		if pos >= len(data) {
+			return codes, fmt.Errorf("truncated CFF encoding")
+		}
+		first, count := int(data[pos]), 1
+		pos++
+		switch data[0] & 0x7f {
+		case 0:
+		case 1:
+			if pos >= len(data) {
+				return codes, fmt.Errorf("truncated CFF encoding range")
+			}
+			count += int(data[pos])
+			pos++
+		default:
+			return codes, fmt.Errorf("invalid CFF encoding format")
+		}
+		if first+count > len(codes) || gid+count > len(sids) {
+			return codes, fmt.Errorf("CFF encoding range out of bounds")
+		}
+		for code := first; code < first+count; code++ {
+			if codes[code] != 0 {
+				return codes, fmt.Errorf("duplicate CFF encoding")
+			}
+			codes[code] = uint16(gid)
+			gid++
+		}
+	}
+	if data[0]&0x80 != 0 {
+		if pos >= len(data) {
+			return codes, fmt.Errorf("truncated CFF encoding supplements")
+		}
+		count := int(data[pos])
+		pos++
+		if count > (len(data)-pos)/3 {
+			return codes, fmt.Errorf("truncated CFF encoding supplements")
+		}
+		for range count {
+			code, sid := data[pos], int(binary.BigEndian.Uint16(data[pos+1:]))
+			pos += 3
+			mapped := slices.Index(sids[:gid], sid)
+			if codes[code] != 0 || mapped <= 0 {
+				return codes, fmt.Errorf("invalid CFF supplemental glyph")
+			}
+			codes[code] = uint16(mapped)
+		}
+	}
+	if data[0]&0x7f > 1 || pos != len(data) {
+		return codes, fmt.Errorf("invalid CFF encoding length or format")
+	}
+	return codes, nil
+}
+
+// encodeCFFSubsetEncoding 按新字形顺序重建主编码及同字形的补充编码
+// 入参: codes 原编码映射, sids 原字符集, ids 新编号对应的原编号
+// 返回: []byte 编码数据, error 字形顺序不满足编码约束
+func encodeCFFSubsetEncoding(codes [256]uint16, sids []int, ids []uint16) ([]byte, error) {
+	var base, supplements []byte
+	encodings := make(map[uint16][]byte)
+	for code, gid := range codes {
+		if gid != 0 {
+			encodings[gid] = append(encodings[gid], byte(code))
+		}
+	}
+	unencoded := false
+	for _, gid := range ids[1:] {
+		values := encodings[gid]
+		if len(values) == 0 {
+			unencoded = true
+		} else if unencoded {
+			return nil, fmt.Errorf("CFF encoded glyph follows unencoded glyph")
+		} else {
+			base = append(base, values[0])
+			for _, code := range values[1:] {
+				supplements = append(supplements, code)
+				supplements = binary.BigEndian.AppendUint16(supplements, uint16(sids[gid]))
+			}
+		}
+	}
+	var result []byte
+	if len(base) == 256 {
+		for index, code := range base {
+			if int(code) != index {
+				return nil, fmt.Errorf("CFF encoding exceeds format zero capacity")
+			}
+		}
+		result = []byte{1, 1, 0, 255}
+	} else {
+		result = append([]byte{0, byte(len(base))}, base...)
+	}
+	if len(supplements) != 0 {
+		result[0] |= 0x80
+		result = append(result, byte(len(supplements)/3))
+		result = append(result, supplements...)
+	}
+	return result, nil
+}

internal/base/font/cff_names.go

@@ -12,9 +12,11 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package font
 
-import "strings"
+import (
+	"strings"
+)
 
 // cffExpertCharset 按CFF规范附录C保存Expert字符集的SID顺序
 var cffExpertCharset = [...]uint16{

internal/base/font/cff_subset.go

@@ -0,0 +1,325 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package font
+
+import (
+	"bytes"
+	"fmt"
+	"maps"
+)
+
+// subsetCFFFont 裁剪CFF字体，保留组合组件和度量，按需重排字形
+// 入参: sfnt 已解析字体, glyphs 使用的字形, preserve 是否保留原字形编号
+// 返回: []byte 字体子集, error 裁剪错误
+func subsetCFFFont(sfnt *SFNT, glyphs []uint16, preserve bool) ([]byte, error) {
+	keep := map[uint16]bool{0: true}
+	for _, gid := range glyphs {
+		if gid >= sfnt.NumGlyphs() {
+			return nil, fmt.Errorf("CFF glyph index out of range")
+		}
+		keep[gid] = true
+	}
+	data, err := subsetCFFCharstrings(sfnt.Tables["CFF "], keep)
+	if err != nil {
+		return bytes.Clone(sfnt.Write()), nil
+	}
+	if !preserve {
+		if compact, ids, err := compactCFFGlyphs(data, keep); err == nil {
+			return compactCFFTables(sfnt, compact, ids)
+		}
+	}
+	tables := maps.Clone(sfnt.Tables)
+	tables["CFF "] = data
+	mapping := make(map[rune]uint16)
+	for gid := range keep {
+		for _, char := range sfnt.glyphCharacters(gid) {
+			mapping[char] = gid
+		}
+	}
+	tables["cmap"] = BuildCmapTable(sfnt.NumGlyphs(), mapping)
+	for _, tag := range []string{"DSIG", "GSUB", "GPOS", "GDEF"} {
+		delete(tables, tag)
+	}
+	return SerializeOTF(tables)
+}
+
+// subsetCFFCharstrings 清空未引用的Type2轮廓及子程序，保留原字宽、提示和编号
+// 入参: data CFF数据, keep 保留的字形，调用后包含组合组件
+// 返回: []byte 重建的CFF数据, error 结构或依赖错误
+func subsetCFFCharstrings(data []byte, keep map[uint16]bool) ([]byte, error) {
+	font, err := readType2Font(data)
+	if err != nil {
+		cid, err := readCIDSubsetFont(data)
+		if err != nil {
+			return nil, err
+		}
+		chars, err := subsetType2Programs(cid.fonts, cid.selects, keep)
+		if err != nil {
+			return nil, err
+		}
+		return cid.write(chars)
+	}
+	chars, err := subsetType2Programs([]*type2Font{font}, nil, keep)
+	if err != nil {
+		return nil, err
+	}
+	return rebuildNamedCFF(data, font, chars, nil)
+}
+
+// subsetType2Programs 按字形所属字典收集子程序依赖并清空未使用的轮廓
+// 入参: fonts 执行资源, selects 字形所属字典，单字典时可为空, keep 保留的字形
+// 返回: [][]byte 字形程序, error 执行或字宽错误
+func subsetType2Programs(fonts []*type2Font, selects []int, keep map[uint16]bool) ([][]byte, error) {
+	keep[0] = true
+	programs := fonts[0].chars
+	locals := make([][]bool, len(fonts))
+	empty := make([]map[float64][]byte, len(fonts))
+	for index, font := range fonts {
+		locals[index] = make([]bool, len(font.locals))
+		empty[index] = make(map[float64][]byte)
+	}
+	globals := make([]bool, len(fonts[0].globals))
+	var stack [48]float64
+	for gid := range keep {
+		if int(gid) >= len(programs) {
+			return nil, fmt.Errorf("CFF glyph index out of range")
+		}
+		fd := 0
+		if selects != nil {
+			fd = selects[gid]
+		}
+		font := fonts[fd]
+		steps := 0
+		state := type2State{font: font, args: stack[:0], width: font.def, seed: font.seed + uint64(gid), steps: &steps, dependencies: keep, localUsage: locals[fd], globalUsage: globals}
+		if _, err := state.run(font.chars[gid], 0); err != nil {
+			return nil, err
+		}
+	}
+	chars := make([][]byte, len(programs))
+	for gid, program := range programs {
+		if keep[uint16(gid)] {
+			chars[gid] = program
+			continue
+		}
+		fd := 0
+		if selects != nil {
+			fd = selects[gid]
+		}
+		font := fonts[fd]
+		steps := 0
+		state := type2State{font: font, args: stack[:0], width: font.def, widthOnly: true, seed: font.seed + uint64(gid), steps: &steps, dependencies: keep}
+		if _, err := state.run(program, 0); err != nil {
+			return nil, err
+		}
+		if encoded, ok := empty[fd][state.width]; ok {
+			chars[gid] = encoded
+			continue
+		}
+		var encoded bytes.Buffer
+		if state.width != font.def {
+			value := state.width - font.nominal
+			divisor := 1
+			if value < -32768 || value >= 32768 {
+				divisor = 2
+			}
+			for range divisor {
+				if err := encodeType2Number(&encoded, value/float64(divisor)); err != nil {
+					return nil, err
+				}
+			}
+			if parseNumberType2(encoded.Bytes(), 0)*float64(divisor) != value {
+				return nil, fmt.Errorf("CFF width cannot be represented exactly")
+			}
+			if divisor == 2 {
+				encoded.Write([]byte{12, 10})
+			}
+		}
+		encoded.WriteByte(14)
+		chars[gid] = encoded.Bytes()
+		empty[fd][state.width] = chars[gid]
+	}
+	globalPrograms := subsetCFFSubroutines(fonts[0].globals, globals)
+	for index, font := range fonts {
+		font.locals = subsetCFFSubroutines(font.locals, locals[index])
+		font.globals = globalPrograms
+	}
+	return chars, nil
+}
+
+// subsetCFFSubroutines 将未引用的子程序替换为空返回，保持调用编号及偏移基数
+// 入参: programs 子程序索引, used 引用标记
+// 返回: [][]byte 裁剪后的子程序索引
+func subsetCFFSubroutines(programs [][]byte, used []bool) [][]byte {
+	result := make([][]byte, len(programs))
+	empty := []byte{11}
+	for index, program := range programs {
+		if used[index] {
+			result[index] = program
+		} else {
+			result[index] = empty
+		}
+	}
+	return result
+}
+
+// rebuildNamedCFF 重建非CID的CFF偏移，保留字符集、编码和私有提示参数
+// 入参: data 原始CFF数据, font 执行资源, chars 替换后的字形程序, ids 字形重排顺序，nil时保留原编号
+// 返回: []byte 重建的CFF数据, error 不支持的结构
+func rebuildNamedCFF(data []byte, font *type2Font, chars [][]byte, ids []uint16) ([]byte, error) {
+	names, end, err := readType2Index(data, int(data[2]))
+	if err != nil {
+		return nil, err
+	}
+	tops, end, err := readType2Index(data, end)
+	if err != nil || len(tops) != 1 {
+		return nil, fmt.Errorf("invalid CFF top dictionary")
+	}
+	strings, _, err := readType2Index(data, end)
+	if err != nil {
+		return nil, err
+	}
+	dict, err := readCFFDict(tops[0])
+	if err != nil {
+		return nil, err
+	}
+	for op := range dict {
+		switch op {
+		case 0, 1, 2, 3, 4, 5, 13, 14, 15, 16, 17, 18, 1200, 1201, 1202, 1203, 1204, 1205, 1206, 1207, 1208, 1222, 1223:
+		default:
+			return nil, fmt.Errorf("unsupported CFF top operator %d", op)
+		}
+	}
+	sids, _, _, _, ok := getCFFCharsetInfo(data, len(font.chars))
+	if !ok {
+		return nil, fmt.Errorf("invalid CFF charset")
+	}
+	encoding, err := cffSubsetEncoding(data, dict)
+	if err != nil {
+		return nil, err
+	}
+	if ids != nil {
+		if encoding != nil {
+			codes, err := readCFFSubsetEncoding(encoding, sids)
+			if err != nil {
+				return nil, err
+			}
+			encoding, err = encodeCFFSubsetEncoding(codes, sids, ids)
+			if err != nil {
+				return nil, err
+			}
+		}
+		selected := make([]int, len(ids))
+		for index, gid := range ids {
+			selected[index] = sids[gid]
+		}
+		sids = selected
+	}
+	charset := encodeCFFSubsetCharset(sids)
+	private, err := readType2Private(data, dict[18], &type2Font{})
+	if err != nil {
+		return nil, err
+	}
+	if err := normalizeCFFPrivate(private); err != nil {
+		return nil, err
+	}
+	privateData, err := encodeCFFSubsetPrivate(private)
+	if err != nil {
+		return nil, err
+	}
+	prefix := bytes.Clone(data[:int(data[2])])
+	prefix = append(prefix, encodeCFFIndex(names)...)
+	suffix := encodeCFFIndex(strings)
+	suffix = append(suffix, encodeCFFIndex(font.globals)...)
+	encodedChars := encodeCFFIndex(chars)
+	var top []byte
+	for attempt := 0; attempt < 16; attempt++ {
+		top = encodeCFFIndex([][]byte{encodeCFFDict(dict)})
+		offset := len(prefix) + len(top) + len(suffix)
+		updated := maps.Clone(dict)
+		updated[15] = []float64{float64(offset)}
+		offset += len(charset)
+		if encoding != nil {
+			updated[16] = []float64{float64(offset)}
+		}
+		offset += len(encoding)
+		updated[17] = []float64{float64(offset)}
+		updated[18] = []float64{float64(len(privateData)), float64(offset + len(encodedChars))}
+		encoded := encodeCFFIndex([][]byte{encodeCFFDict(updated)})
+		if len(encoded) == len(top) {
+			result := prefix
+			for _, part := range [][]byte{encoded, suffix, charset, encoding, encodedChars, privateData, encodeCFFIndex(font.locals)} {
+				result = append(result, part...)
+			}
+			return result, nil
+		}
+		dict = updated
+	}
+	return nil, fmt.Errorf("CFF dictionary offsets did not converge")
+}
+
+// encodeCFFSubsetPrivate 保留私有字典参数，将局部子程序安排在字典之后
+// 入参: private 私有字典
+// 返回: []byte 字典数据, error 不支持的参数或偏移错误
+func encodeCFFSubsetPrivate(private cffDict) ([]byte, error) {
+	for op := range private {
+		switch op {
+		case 6, 7, 8, 9, 10, 11, 19, 20, 21, 1209, 1210, 1211, 1212, 1213, 1214, 1217, 1218, 1219:
+		default:
+			return nil, fmt.Errorf("unsupported CFF private operator %d", op)
+		}
+	}
+	for range 16 {
+		data := encodeCFFDict(private)
+		value, ok := private[19]
+		if !ok || len(value) == 1 && value[0] == float64(len(data)) {
+			return data, nil
+		}
+		private[19] = []float64{float64(len(data))}
+	}
+	return nil, fmt.Errorf("CFF private offset did not converge")
+}
+
+// cffSubsetEncoding 读取自定义CFF编码及补充映射，预定义编码无需复制
+// 入参: data CFF数据, dict 顶层字典
+// 返回: []byte 编码数据, error 编码格式错误
+func cffSubsetEncoding(data []byte, dict cffDict) ([]byte, error) {
+	values := dict[16]
+	if values == nil || len(values) == 1 && (values[0] == 0 || values[0] == 1) {
+		return nil, nil
+	}
+	start, err := cffDictOffset(data, dict, 16)
+	if err != nil || start > len(data)-2 {
+		return nil, fmt.Errorf("invalid CFF encoding offset")
+	}
+	end := start + 2
+	switch data[start] & 0x7f {
+	case 0:
+		end += int(data[start+1])
+	case 1:
+		end += 2 * int(data[start+1])
+	default:
+		return nil, fmt.Errorf("invalid CFF encoding format")
+	}
+	if data[start]&0x80 != 0 {
+		if end >= len(data) {
+			return nil, fmt.Errorf("truncated CFF encoding supplements")
+		}
+		end += 1 + 3*int(data[end])
+	}
+	if end > len(data) {
+		return nil, fmt.Errorf("truncated CFF encoding")
+	}
+	return data[start:end], nil
+}

internal/base/font/cff_type1.go

@@ -12,9 +12,11 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package font
 
-import "fmt"
+import (
+	"fmt"
+)
 
 // cffCharstringType 读取CFF字形程序类型，缺省为Type2
 // 入参: dict 顶层字典
@@ -32,13 +34,13 @@ func cffCharstringType(dict cffDict) (int, error) {
 
 // readCFFType1Program 读取Type1字形及无偏置局部子程序，保留源字形顺序
 // 入参: data CFF字体, chars 字形程序, private 私有字典范围, cid 是否为CID字体
-// 返回: *type1Program 执行资源, error 字符集或私有字典错误
-func readCFFType1Program(data []byte, chars [][]byte, private []float64, cid bool) (*type1Program, error) {
+// 返回: *Type1Program 执行资源, error 字符集或私有字典错误
+func readCFFType1Program(data []byte, chars [][]byte, private []float64, cid bool) (*Type1Program, error) {
 	resources := &type2Font{}
 	if _, err := readType2Private(data, private, resources); err != nil {
 		return nil, err
 	}
-	program := &type1Program{subrs: resources.locals, lenIV: -1}
+	program := &Type1Program{subrs: resources.locals, lenIV: -1}
 	if cid {
 		return program, nil
 	}

internal/base/font/cmap.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package font
 
 import (
 	"bytes"
@@ -31,10 +31,10 @@ type cmapSegment struct {
 	offset     uint16
 }
 
-// normalizeCmap 转换扩展字符子表，保留各编码记录及原字形编号
+// NormalizeCmap 转换扩展字符子表，保留各编码记录及原字形编号
 // 入参: data 字符映射表
 // 返回: []byte 等价字符映射表, error 子表错误
-func normalizeCmap(data []byte) ([]byte, error) {
+func NormalizeCmap(data []byte) ([]byte, error) {
 	if len(data) < 4 {
 		return data, nil
 	}
@@ -76,7 +76,7 @@ func normalizeCmap(data []byte) ([]byte, error) {
 			if err != nil {
 				return nil, err
 			}
-			table := buildCmapTable(0, mapping)
+			table := BuildCmapTable(0, mapping)
 			if language > 65535 {
 				table = buildCmapTableFormat12(0, mapping)
 			}
@@ -255,17 +255,17 @@ func parseCmapFormat2(data []byte) (map[rune]uint16, error) {
 	return mapping, nil
 }
 
-// packedGlyphRune 获取包装字体字符
+// PackedGlyphRune 获取包装字体字符
 // 入参: gid 字形ID
 // 返回: rune 包装字体字符
-func packedGlyphRune(gid uint16) rune {
+func PackedGlyphRune(gid uint16) rune {
 	return 0xF0000 + rune(gid)
 }
 
-// parseCmapMappings 解析cmap字符映射
+// ParseCmapMappings 解析cmap字符映射
 // 入参: data cmap表数据
 // 返回: map[rune]uint16 字符到字形映射
-func parseCmapMappings(data []byte) map[rune]uint16 {
+func ParseCmapMappings(data []byte) map[rune]uint16 {
 	if len(data) < 4 {
 		return nil
 	}
@@ -427,18 +427,18 @@ func parseCmapFormat12(data []byte, result map[rune]uint16) {
 	}
 }
 
-// addPackedGlyphMapping 添加字形ID私有映射
+// AddPackedGlyphMapping 添加字形ID私有映射
 // 入参: mapping 字符映射, numGlyphs 字形数量
-func addPackedGlyphMapping(mapping map[rune]uint16, numGlyphs uint16) {
+func AddPackedGlyphMapping(mapping map[rune]uint16, numGlyphs uint16) {
 	for i := uint16(0); i < numGlyphs; i++ {
-		mapping[packedGlyphRune(i)] = i
+		mapping[PackedGlyphRune(i)] = i
 	}
 }
 
-// buildCmapTable 构建格式4或12字符映射，省略缺字映射
+// BuildCmapTable 构建格式4或12字符映射，省略缺字映射
 // 入参: numGlyphs 字形数量, mapping 字符映射
 // 返回: []byte cmap表数据
-func buildCmapTable(numGlyphs uint16, mapping map[rune]uint16) []byte {
+func BuildCmapTable(numGlyphs uint16, mapping map[rune]uint16) []byte {
 	if shouldBuildCmapFormat12(mapping) {
 		return buildCmapTableFormat12(numGlyphs, mapping)
 	}

internal/base/font/cmap_variation.go

@@ -0,0 +1,234 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package font
+
+import (
+	"encoding/binary"
+	"maps"
+	"slices"
+	"unicode/utf8"
+
+	"github.com/go-text/typesetting/font/opentype/tables"
+)
+
+// subsetCmapVariations 裁剪Unicode变体映射，将非默认变体的字形加入保留集合
+// 入参: data 字符映射表, chars 使用字符, glyphs 保留字形, count 字形总数
+// 返回: []byte 格式14子表，无变体时为空, bool 映射是否有效
+func subsetCmapVariations(data []byte, chars map[rune]bool, glyphs map[uint16]bool, count uint16) ([]byte, bool) {
+	if len(data) < 4 {
+		return nil, false
+	}
+	n := int(binary.BigEndian.Uint16(data[2:]))
+	if n > (len(data)-4)/8 {
+		return nil, false
+	}
+	var source []byte
+	for i := 0; i < n; i++ {
+		record := data[4+i*8:]
+		offset := uint64(binary.BigEndian.Uint32(record[4:]))
+		if offset < uint64(4+n*8) || offset+2 > uint64(len(data)) {
+			return nil, false
+		}
+		if binary.BigEndian.Uint16(data[offset:]) != 14 {
+			continue
+		}
+		if source != nil || binary.BigEndian.Uint16(record) != 0 || binary.BigEndian.Uint16(record[2:]) != 5 || offset+10 > uint64(len(data)) {
+			return nil, false
+		}
+		length := uint64(binary.BigEndian.Uint32(data[offset+2:]))
+		if length < 10 || offset+length > uint64(len(data)) {
+			return nil, false
+		}
+		source = data[offset : offset+length]
+	}
+	if source == nil {
+		return nil, true
+	}
+	return subsetCmapVariationTable(source, chars, glyphs, count)
+}
+
+// subsetCmapVariationTable 按使用字符筛选默认及非默认变体，保持选择符和映射有序
+// 入参: data 格式14子表, chars 使用字符, glyphs 保留字形, count 字形总数
+// 返回: []byte 裁剪后的子表, bool 子表是否有效
+func subsetCmapVariationTable(data []byte, chars map[rune]bool, glyphs map[uint16]bool, count uint16) ([]byte, bool) {
+	n := uint64(binary.BigEndian.Uint32(data[6:]))
+	header := 10 + n*11
+	if header > uint64(len(data)) {
+		return nil, false
+	}
+	used := slices.Sorted(maps.Keys(chars))
+	var records, payload []byte
+	previous := rune(-1)
+	for i := uint64(0); i < n; i++ {
+		raw := data[10+i*11:]
+		for j, size := range []uint64{4, 5} {
+			offset := uint64(binary.BigEndian.Uint32(raw[3+j*4:]))
+			if offset == 0 {
+				continue
+			}
+			if offset < header || offset+4 > uint64(len(data)) {
+				return nil, false
+			}
+			entries := uint64(binary.BigEndian.Uint32(data[offset:]))
+			if offset+4+entries*size > uint64(len(data)) {
+				return nil, false
+			}
+		}
+		record, _, err := tables.ParseVariationSelector(raw, data)
+		selector := cmapVariationRune(record.VarSelector)
+		if err != nil || !utf8.ValidRune(selector) || selector <= previous || !validCmapVariation(record, count) {
+			return nil, false
+		}
+		previous = selector
+		if !chars[selector] {
+			continue
+		}
+		defaults := subsetCmapDefaultVariations(record.DefaultUVS.Ranges, used)
+		var alternatives []byte
+		for _, entry := range record.NonDefaultUVS.Ranges {
+			if chars[cmapVariationRune(entry.UnicodeValue)] {
+				alternatives = append(alternatives, entry.UnicodeValue[:]...)
+				alternatives = binary.BigEndian.AppendUint16(alternatives, uint16(entry.GlyphID))
+				glyphs[uint16(entry.GlyphID)] = true
+			}
+		}
+		if len(defaults)+len(alternatives) == 0 {
+			continue
+		}
+		start := len(records)
+		records = append(records, record.VarSelector[:]...)
+		records = append(records, make([]byte, 8)...)
+		for j, entries := range [][]byte{defaults, alternatives} {
+			if len(entries) == 0 {
+				continue
+			}
+			binary.BigEndian.PutUint32(records[start+3+j*4:], uint32(len(payload)+1))
+			payload = binary.BigEndian.AppendUint32(payload, uint32(len(entries)/(4+j)))
+			payload = append(payload, entries...)
+		}
+	}
+	if len(records) == 0 {
+		return nil, true
+	}
+	if uint64(len(records))+uint64(len(payload))+10 > 1<<32-1 {
+		return nil, false
+	}
+	for i := 0; i < len(records); i += 11 {
+		for _, j := range []int{3, 7} {
+			offset := binary.BigEndian.Uint32(records[i+j:])
+			if offset != 0 {
+				binary.BigEndian.PutUint32(records[i+j:], offset-1+uint32(10+len(records)))
+			}
+		}
+	}
+	out := make([]byte, 10, 10+len(records)+len(payload))
+	binary.BigEndian.PutUint16(out, 14)
+	binary.BigEndian.PutUint32(out[2:], uint32(cap(out)))
+	binary.BigEndian.PutUint32(out[6:], uint32(len(records)/11))
+	out = append(out, records...)
+	return append(out, payload...), true
+}
+
+// validCmapVariation 检查变体映射的字符范围、排序、互斥关系及字形编号
+// 入参: record 选择符记录, count 字形总数
+// 返回: bool 映射是否有效
+func validCmapVariation(record tables.VariationSelector, count uint16) bool {
+	defaults := record.DefaultUVS.Ranges
+	previous := rune(-1)
+	for _, entry := range defaults {
+		first := cmapVariationRune(entry.StartUnicodeValue)
+		last := first + rune(entry.AdditionalCount)
+		if first <= previous || !utf8.ValidRune(first) || !utf8.ValidRune(last) || first < 0xd800 && last >= 0xd800 {
+			return false
+		}
+		previous = last
+	}
+	previous = -1
+	index := 0
+	for _, entry := range record.NonDefaultUVS.Ranges {
+		char := cmapVariationRune(entry.UnicodeValue)
+		if char <= previous || !utf8.ValidRune(char) || uint16(entry.GlyphID) >= count {
+			return false
+		}
+		previous = char
+		for index < len(defaults) && cmapVariationRune(defaults[index].StartUnicodeValue)+rune(defaults[index].AdditionalCount) < char {
+			index++
+		}
+		if index < len(defaults) && cmapVariationRune(defaults[index].StartUnicodeValue) <= char {
+			return false
+		}
+	}
+	return true
+}
+
+// subsetCmapDefaultVariations 筛选默认变体的使用字符，将连续字符合并为格式14范围
+// 入参: ranges 默认变体范围, chars 已排序的使用字符
+// 返回: []byte 范围记录，不含数量字段
+func subsetCmapDefaultVariations(ranges []tables.UnicodeRange, chars []rune) []byte {
+	var out []byte
+	index := 0
+	last := rune(-2)
+	for _, char := range chars {
+		for index < len(ranges) && cmapVariationRune(ranges[index].StartUnicodeValue)+rune(ranges[index].AdditionalCount) < char {
+			index++
+		}
+		if index == len(ranges) {
+			break
+		}
+		if cmapVariationRune(ranges[index].StartUnicodeValue) > char {
+			continue
+		}
+		if char == last+1 && out[len(out)-1] < 255 {
+			out[len(out)-1]++
+		} else {
+			out = append(out, byte(char>>16), byte(char>>8), byte(char), 0)
+		}
+		last = char
+	}
+	return out
+}
+
+// cmapVariationRune 读取变体映射中的24位Unicode码点
+// 入参: value 三字节码点
+// 返回: rune Unicode码点
+func cmapVariationRune(value [3]byte) rune {
+	return rune(value[0])<<16 | rune(value[1])<<8 | rune(value[2])
+}
+
+// buildCmapWithVariations 在生成的Unicode映射中插入格式14记录，保持编码记录有序
+// 入参: count 字形总数, mapping 字符映射, variations 格式14子表
+// 返回: []byte 字符映射表
+func buildCmapWithVariations(count uint16, mapping map[rune]uint16, variations []byte) []byte {
+	base := BuildCmapTable(count, mapping)
+	if len(variations) == 0 {
+		return base
+	}
+	payload := base[binary.BigEndian.Uint32(base[8:]):]
+	out := make([]byte, 28, 28+len(payload)+len(variations))
+	binary.BigEndian.PutUint16(out[2:], 3)
+	encoding := uint16(3)
+	if binary.BigEndian.Uint16(payload) == 12 {
+		encoding = 4
+	}
+	binary.BigEndian.PutUint16(out[6:], encoding)
+	binary.BigEndian.PutUint32(out[8:], 28)
+	binary.BigEndian.PutUint16(out[14:], 5)
+	binary.BigEndian.PutUint32(out[16:], uint32(28+len(payload)))
+	last := 4 + 8*(int(binary.BigEndian.Uint16(base[2:]))-1)
+	copy(out[20:28], base[last:last+8])
+	binary.BigEndian.PutUint32(out[24:], 28)
+	out = append(out, payload...)
+	return append(out, variations...)
+}

internal/base/font/file.go

@@ -0,0 +1,221 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package font
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"encoding/binary"
+	"fmt"
+	"strings"
+	"unicode/utf8"
+)
+
+// Face 字体文件中的字体名称与零起始索引，不依赖文件名
+// Family和Style为排版族，MenuFamily和MenuStyle为兼容四款式的菜单名称
+// FamilyKey区分兼容族、厂商和版本，未知时为空；Bold和Italic表示字体固有样式
+type Face struct {
+	Index          int      `json:"index"`
+	FullName       string   `json:"fullName"`
+	Family         string   `json:"family"`
+	Style          string   `json:"style"`
+	PostScriptName string   `json:"postscriptName"`
+	Names          []string `json:"names"`
+	MenuFamily     string   `json:"menuFamily"`
+	MenuStyle      string   `json:"menuStyle"`
+	FamilyKey      string   `json:"familyKey"`
+	Bold           bool     `json:"bold"`
+	Italic         bool     `json:"italic"`
+}
+
+// FaceInfo 从名称表读取字体信息
+// 入参: data 名称表数据, index 零起始字体索引
+// 返回: Face 字体信息
+func FaceInfo(data []byte, index int) Face {
+	return faceInfoLanguage(data, index, 0xffff, 0xffff)
+}
+
+// faceInfoLanguage 优先读取指定平台和语言的显示名称，保留标识及全部别名
+// 入参: data 名称表数据, index 字体索引, platform 平台标识, language 语言标识
+// 返回: Face 字体信息
+func faceInfoLanguage(data []byte, index int, platform, language uint16) Face {
+	records, values := fontNameValues(data)
+	name := func(ids ...uint16) string {
+		for _, id := range ids {
+			for _, record := range records {
+				if record.Name == id {
+					if value := strings.TrimSpace(values[[4]uint16{record.Platform, record.Encoding, record.Language, id}]); value != "" {
+						return value
+					}
+				}
+			}
+		}
+		return ""
+	}
+	localized := func(ids ...uint16) string {
+		for _, id := range ids {
+			for _, record := range records {
+				if record.Platform == platform && record.Language == language && record.Name == id {
+					if value := strings.TrimSpace(values[[4]uint16{record.Platform, record.Encoding, record.Language, id}]); value != "" {
+						return value
+					}
+				}
+			}
+		}
+		return name(ids...)
+	}
+	key := ""
+	if family, version := name(1), name(5); family != "" && version != "" {
+		key = fmt.Sprintf("%x", sha256.Sum256([]byte(strings.Join([]string{family, version, name(8)}, "\x00"))))
+	}
+	family, style := localized(1), localized(2)
+	if family == "" {
+		family = localized(16, 4, 6)
+	}
+	if style == "" {
+		style = localized(17)
+	}
+	return Face{Index: index, FullName: localized(4, 6, 16, 1), Family: localized(16, 1), Style: localized(17, 2), PostScriptName: name(6), Names: fontNamesFromValues(records, values), MenuFamily: family, MenuStyle: style, FamilyKey: key}
+}
+
+// TableFaceInfo 读取名称及字体固有款式，名称键不随显示语言变化
+// 入参: tables 字体表, index 集合索引, platform 平台标识, language 语言标识
+// 返回: Face 字体信息
+func TableFaceInfo(tables map[string][]byte, index int, platform, language uint16) Face {
+	face := faceInfoLanguage(tables["name"], index, platform, language)
+	key := face.FamilyKey
+	if head := tables["head"]; len(head) >= 46 {
+		key += string(head[4:8])
+		style := binary.BigEndian.Uint16(head[44:])
+		face.Bold, face.Italic = style&1 != 0, style&2 != 0
+	}
+	if os2 := tables["OS/2"]; len(os2) >= 64 {
+		key += string(os2[58:62])
+		style := binary.BigEndian.Uint16(os2[62:])
+		face.Bold, face.Italic = style&32 != 0, style&1 != 0 || style&512 != 0
+	}
+	if face.FamilyKey != "" {
+		face.FamilyKey = fmt.Sprintf("%x", sha256.Sum256([]byte(key)))
+	}
+	return face
+}
+
+// FileCount 校验字体或集合头并读取字体数量
+// 入参: data OpenType数据
+// 返回: int 字体数量, error 格式错误
+func FileCount(data []byte) (int, error) {
+	if len(data) < 12 {
+		return 0, fmt.Errorf("invalid font header")
+	}
+	switch string(data[:4]) {
+	case "\x00\x01\x00\x00", "OTTO", "true":
+		return 1, nil
+	case "ttcf":
+		version := binary.BigEndian.Uint32(data[4:])
+		count := uint64(binary.BigEndian.Uint32(data[8:]))
+		if (version != 0x00010000 && version != 0x00020000) || count == 0 || count > uint64(len(data)-12)/4 {
+			return 0, fmt.Errorf("invalid font collection header")
+		}
+		return int(count), nil
+	default:
+		return 0, fmt.Errorf("invalid OpenType header")
+	}
+}
+
+// ReadFaces 读取已解封装字体或集合的名称信息
+// 入参: data OpenType数据
+// 返回: []Face 字体列表, error 格式或名称表错误
+func ReadFaces(data []byte) ([]Face, error) {
+	return ReadLocalizedFaces(data, 0xffff, 0xffff)
+}
+
+// ReadLocalizedFaces 读取指定平台和语言的字体名称，缺失时沿用名称表顺序
+// 入参: data OpenType数据, platform 名称表平台标识, language 名称表语言标识
+// 返回: []Face 字体列表, error 格式或名称表错误
+func ReadLocalizedFaces(data []byte, platform, language uint16) ([]Face, error) {
+	count, err := FileCount(data)
+	if err != nil {
+		return nil, err
+	}
+	faces := make([]Face, 0, count)
+	for index := 0; index < count; index++ {
+		tables, err := FileTables(data, index)
+		if err != nil {
+			return nil, err
+		}
+		face := TableFaceInfo(tables, index, platform, language)
+		if face.FullName == "" {
+			return nil, fmt.Errorf("font %d has no usable name", index)
+		}
+		faces = append(faces, face)
+	}
+	return faces, nil
+}
+
+// ExtractFace 提取已解封装字体中的集合项，规范字符映射并保留原始表
+// 入参: data OpenType数据, index 零起始字体索引
+// 返回: []byte 独立字体数据, error 格式或索引错误
+func ExtractFace(data []byte, index int) ([]byte, error) {
+	var err error
+	if bytes.HasPrefix(data, []byte("ttcf")) {
+		data, err = ExtractCollectionFont(data, index)
+		if err != nil {
+			return nil, err
+		}
+		index = 0
+	}
+	tables, err := FileTables(data, index)
+	if err != nil {
+		return nil, err
+	}
+	cmap, err := NormalizeCmap(tables["cmap"])
+	if err != nil {
+		return nil, err
+	}
+	if !bytes.Equal(cmap, tables["cmap"]) {
+		tables["cmap"] = cmap
+		return SerializeOTF(tables)
+	}
+	return bytes.Clone(data), nil
+}
+
+// MissingGlyphs 检查独立字体的字符覆盖，忽略段落换行并按首次出现顺序去重
+// 入参: data 独立OpenType数据, text 待检查文字
+// 返回: string 缺失字符, error 字体或文字格式错误
+func MissingGlyphs(data []byte, text string) (string, error) {
+	if !utf8.ValidString(text) {
+		return "", fmt.Errorf("text must be UTF-8")
+	}
+	data, err := DefaultCFF2Font(data)
+	if err != nil {
+		return "", err
+	}
+	sfnt, err := ParseSFNT(data)
+	if err != nil {
+		return "", err
+	}
+	seen := make(map[rune]bool)
+	var missing strings.Builder
+	for _, char := range text {
+		if char == '\r' || char == '\n' || seen[char] {
+			continue
+		}
+		seen[char] = true
+		if sfnt.GlyphIndex(char) == 0 {
+			missing.WriteRune(char)
+		}
+	}
+	return missing.String(), nil
+}

internal/base/font/glyf.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package font
 
 import (
 	"encoding/binary"
@@ -21,12 +21,16 @@ import (
 	"math"
 	"sync"
 
-	"github.com/tdewolff/font"
+	"github.com/go-text/typesetting/font/cff"
+	"github.com/go-text/typesetting/font/opentype"
 )
 
-// sfntOutliner 缓存字体程序并提取独立字形轮廓
-type sfntOutliner struct {
-	font     *font.SFNT
+// Outliner 缓存字体程序并提取独立字形轮廓
+type Outliner struct {
+	Font     *SFNT
+	cffOnce  sync.Once
+	cff      *cff.CFF
+	cffErr   error
 	once     sync.Once
 	program  *ttInterpreter
 	err      error
@@ -42,12 +46,52 @@ type ttGlyph struct {
 	warning error
 }
 
-// path 按TrueType指令和隐含点规则生成闭合轮廓，CFF保留原有解析
+// Path 按字体设计坐标提取闭合轮廓，TrueType保留字形指令处理
 // 入参: path 路径接收器, glyph 字形编号, scale 字体单位缩放
 // 返回: error 字形解析错误
-func (f *sfntOutliner) path(path font.Pather, glyph uint16, scale float64) error {
-	if !f.font.IsTrueType {
-		return f.font.GlyphPath(path, glyph, 0, 0, 0, scale, font.NoHinting)
+func (f *Outliner) Path(path glyphPather, glyph uint16, scale float64) error {
+	type point struct{ X, Y float64 }
+	if !f.Font.IsTrueType {
+		f.cffOnce.Do(func() {
+			data, err := SanitizeCFF(f.Font.Tables["CFF "])
+			if err == nil {
+				data, err = NormalizeCFFCharstringsAt(data, f.Font.UnitsPerEm())
+			}
+			if err != nil {
+				f.cffErr = err
+				return
+			}
+			f.cff, f.cffErr = cff.Parse(data)
+		})
+		if f.cffErr != nil {
+			return f.cffErr
+		}
+		segments, _, err := f.cff.LoadGlyph(glyph)
+		if err != nil {
+			return err
+		}
+		open := false
+		for _, segment := range segments {
+			p := segment.Args
+			switch segment.Op {
+			case opentype.SegmentOpMoveTo:
+				if open {
+					path.Close()
+				}
+				path.MoveTo(float64(p[0].X)*scale, float64(p[0].Y)*scale)
+				open = true
+			case opentype.SegmentOpLineTo:
+				path.LineTo(float64(p[0].X)*scale, float64(p[0].Y)*scale)
+			case opentype.SegmentOpCubeTo:
+				path.CubeTo(float64(p[0].X)*scale, float64(p[0].Y)*scale, float64(p[1].X)*scale, float64(p[1].Y)*scale, float64(p[2].X)*scale, float64(p[2].Y)*scale)
+			default:
+				return fmt.Errorf("invalid CFF curve")
+			}
+		}
+		if open {
+			path.Close()
+		}
+		return nil
 	}
 	contour, err := f.glyph(glyph, make(map[uint16]bool))
 	if err != nil {
@@ -64,23 +108,23 @@ func (f *sfntOutliner) path(path font.Pather, glyph uint16, scale float64) error
 			first = last + 1
 			continue
 		}
-		point := func(i int) Point {
-			return Point{X: float64(points[i].x) * scale / 64, Y: float64(points[i].y) * scale / 64}
+		coordinate := func(i int) point {
+			return point{X: float64(points[i].x) * scale / 64, Y: float64(points[i].y) * scale / 64}
 		}
-		start, end := point(first), point(last)
+		start, end := coordinate(first), coordinate(last)
 		begin, stop := first, last
 		if points[first].on {
 			begin++
 		} else if points[last].on {
 			start, stop = end, last-1
 		} else {
-			start = Point{X: (start.X + end.X) / 2, Y: (start.Y + end.Y) / 2}
+			start = point{X: (start.X + end.X) / 2, Y: (start.Y + end.Y) / 2}
 		}
 		path.MoveTo(start.X, start.Y)
-		var control Point
+		var control point
 		pending := false
 		for i := begin; i <= stop; i++ {
-			p := point(i)
+			p := coordinate(i)
 			if points[i].on {
 				if pending {
 					path.QuadTo(control.X, control.Y, p.X, p.Y)
@@ -107,14 +151,14 @@ func (f *sfntOutliner) path(path font.Pather, glyph uint16, scale float64) error
 // glyph 解码简单或复合字形并执行对应字节码，不改写字体资源
 // 入参: id 字形编号, active 递归访问集合
 // 返回: ttGlyph 字形轮廓, error 字形错误
-func (f *sfntOutliner) glyph(id uint16, active map[uint16]bool) (ttGlyph, error) {
+func (f *Outliner) glyph(id uint16, active map[uint16]bool) (ttGlyph, error) {
 	var result ttGlyph
-	if id >= f.font.NumGlyphs() || active[id] {
+	if id >= f.Font.NumGlyphs() || active[id] {
 		return result, fmt.Errorf("invalid TrueType component reference %d", id)
 	}
 	active[id] = true
 	defer delete(active, id)
-	data, err := trueTypeGlyphData(f.font.Tables, id)
+	data, err := trueTypeGlyphData(f.Font.Tables, id)
 	if err != nil {
 		return result, err
 	}
@@ -146,14 +190,14 @@ func (f *sfntOutliner) glyph(id uint16, active map[uint16]bool) (ttGlyph, error)
 	if len(program) == 0 {
 		return result, nil
 	}
-	outlineOnly, err := ttOutlineOnly(f.font.Tables, program)
+	outlineOnly, err := ttOutlineOnly(f.Font.Tables, program)
 	if err != nil {
 		return result, err
 	}
 	if outlineOnly {
 		return result, nil
 	}
-	f.once.Do(func() { f.program, f.err = newTTInterpreter(f.font.Tables, f.font.UnitsPerEm()) })
+	f.once.Do(func() { f.program, f.err = newTTInterpreter(f.Font.Tables, f.Font.UnitsPerEm()) })
 	if f.err != nil {
 		if ttRecoverableHint(f.err) {
 			result.warning = f.err
@@ -182,16 +226,16 @@ func (f *sfntOutliner) glyph(id uint16, active map[uint16]bool) (ttGlyph, error)
 // phantomPoints 按水平和垂直度量生成字形末尾的四个虚拟点
 // 入参: id 字形编号, data 完整字形头
 // 返回: [4]ttPoint 左右边距与上下原点
-func (f *sfntOutliner) phantomPoints(id uint16, data []byte) [4]ttPoint {
-	left := int32(int16(binary.BigEndian.Uint16(data[2:]))) - int32(f.font.Hmtx.LeftSideBearing(id))
+func (f *Outliner) phantomPoints(id uint16, data []byte) [4]ttPoint {
+	left := int32(int16(binary.BigEndian.Uint16(data[2:]))) - int32(f.Font.sideBearing(id, false))
 	top := int32(int16(binary.BigEndian.Uint16(data[8:])))
-	if f.font.Vmtx != nil {
-		top += int32(f.font.Vmtx.TopSideBearing(id))
+	if f.Font.vertical != 0 {
+		top += int32(f.Font.sideBearing(id, true))
 	}
-	return [4]ttPoint{{x: left * 64, ox: left * 64}, {x: (left + int32(f.font.GlyphAdvance(id))) * 64, ox: (left + int32(f.font.GlyphAdvance(id))) * 64}, {y: top * 64, oy: top * 64}, {y: (top - int32(f.font.GlyphVerticalAdvance(id))) * 64, oy: (top - int32(f.font.GlyphVerticalAdvance(id))) * 64}}
+	return [4]ttPoint{{x: left * 64, ox: left * 64}, {x: (left + int32(f.Font.GlyphAdvance(id))) * 64, ox: (left + int32(f.Font.GlyphAdvance(id))) * 64}, {y: top * 64, oy: top * 64}, {y: (top - int32(f.Font.GlyphVerticalAdvance(id))) * 64, oy: (top - int32(f.Font.GlyphVerticalAdvance(id))) * 64}}
 }
 
-// ttRecoverableHint 判断栈参数、指令引用或控制流错误是否允许保留执行前轮廓
+// ttRecoverableHint 判断栈参数、区点轮廓及函数引用或控制流错误是否允许保留执行前轮廓
 // 入参: err 指令错误
 // 返回: bool 是否可恢复
 func ttRecoverableHint(err error) bool {
@@ -231,7 +275,7 @@ func trueTypeGlyphData(tables map[string][]byte, id uint16) ([]byte, error) {
 
 // recordGlyphWarning 记录字形恢复提示，允许并发提取轮廓
 // 入参: id 字形编号, warning 恢复原因
-func (f *sfntOutliner) recordGlyphWarning(id uint16, warning error) {
+func (f *Outliner) recordGlyphWarning(id uint16, warning error) {
 	f.mu.Lock()
 	defer f.mu.Unlock()
 	if f.warnings == nil {
@@ -240,10 +284,10 @@ func (f *sfntOutliner) recordGlyphWarning(id uint16, warning error) {
 	f.warnings[id] = warning
 }
 
-// glyphWarning 返回字形恢复为执行前轮廓的原因
+// GlyphWarning 返回字形恢复为执行前轮廓的原因
 // 入参: id 字形编号
 // 返回: error 恢复原因，无恢复时为空
-func (f *sfntOutliner) glyphWarning(id uint16) error {
+func (f *Outliner) GlyphWarning(id uint16) error {
 	f.mu.Lock()
 	defer f.mu.Unlock()
 	return f.warnings[id]
@@ -339,7 +383,7 @@ func readTTSimple(data []byte, count int) (ttGlyph, []byte, error) {
 // composite 合成分量变换和点匹配，保留分量顺序及父级字节码
 // 入参: glyph 父字形编号, data 复合字形数据, phantoms 父字形虚拟点, active 递归访问集合
 // 返回: ttGlyph 字形轮廓, []byte 字节码, error 数据错误
-func (f *sfntOutliner) composite(glyph uint16, data []byte, phantoms [4]ttPoint, active map[uint16]bool) (ttGlyph, []byte, error) {
+func (f *Outliner) composite(glyph uint16, data []byte, phantoms [4]ttPoint, active map[uint16]bool) (ttGlyph, []byte, error) {
 	var result ttGlyph
 	pos := 10
 	total := -1
@@ -432,7 +476,7 @@ func (f *sfntOutliner) composite(glyph uint16, data []byte, phantoms [4]ttPoint,
 			} else {
 				if total < 0 {
 					var err error
-					total, err = trueTypePointCount(f.font.Tables, glyph, map[uint16]int{}, map[uint16]bool{})
+					total, err = trueTypePointCount(f.Font.Tables, glyph, map[uint16]int{}, map[uint16]bool{})
 					if err != nil {
 						return result, nil, err
 					}

internal/base/font/hint.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package font
 
 import (
 	"encoding/binary"
@@ -25,7 +25,7 @@ import (
 // errTTStackUnderflow 表示字形程序缺少必需的栈参数
 var errTTStackUnderflow = errors.New("TrueType instruction stack underflow")
 
-// errTTInvalidReference 表示字形指令引用不存在的点或函数
+// errTTInvalidReference 表示字形指令引用不存在的区、点、轮廓或函数
 var errTTInvalidReference = errors.New("invalid TrueType instruction reference")
 
 // errTTInvalidControlFlow 表示条件分支未闭合或跳转超出字节码范围
@@ -380,7 +380,8 @@ func (v *ttInterpreter) execute(code []byte, depth int) error {
 			case op >= 0x13 && op <= 0x16:
 				z := v.pop()
 				if z < 0 || z > 1 {
-					return fmt.Errorf("invalid TrueType zone")
+					v.err = fmt.Errorf("%w: zone %d", errTTInvalidReference, z)
+					break
 				}
 				if op == 0x16 {
 					g.zone = [3]int32{z, z, z}
@@ -854,7 +855,7 @@ func (v *ttInterpreter) shift(op byte) {
 	if op <= 0x35 {
 		contour := v.pop()
 		if contour < 0 || int64(contour) >= int64(len(v.ends)) {
-			v.err = fmt.Errorf("invalid TrueType contour reference")
+			v.err = fmt.Errorf("%w: contour %d", errTTInvalidReference, contour)
 			return
 		}
 		if contour > 0 {
@@ -864,7 +865,7 @@ func (v *ttInterpreter) shift(op byte) {
 	} else {
 		target = v.pop()
 		if target < 0 || target > 1 {
-			v.err = fmt.Errorf("invalid TrueType zone")
+			v.err = fmt.Errorf("%w: zone %d", errTTInvalidReference, target)
 			return
 		}
 		to = len(v.zones[target])

internal/base/font/loca.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package font
 
 import (
 	"bytes"
@@ -22,19 +22,19 @@ import (
 	"slices"
 )
 
-// errTTInvalidLocations 表示字形索引不满足递增偏移要求
-var errTTInvalidLocations = errors.New("invalid TrueType glyph locations")
+// ErrTTInvalidLocations 表示字形索引不满足递增偏移要求
+var ErrTTInvalidLocations = errors.New("invalid TrueType glyph locations")
 
-// normalizeTrueTypeLocations 验证物理字形边界后按原编号重排，不改变空字形和分量引用
+// NormalizeTrueTypeLocations 验证物理字形边界后按原编号重排，不改变空字形和分量引用
 // 入参: tables 独占字体表目录，表内容只读
 // 返回: bool 是否重建索引, error 无法可靠恢复的索引或轮廓错误
-func normalizeTrueTypeLocations(tables map[string][]byte) (bool, error) {
+func NormalizeTrueTypeLocations(tables map[string][]byte) (bool, error) {
 	if _, ok := tables["glyf"]; !ok {
 		return false, nil
 	}
 	head, maxp, loca, glyf := tables["head"], tables["maxp"], tables["loca"], tables["glyf"]
 	if len(head) < 54 || len(maxp) < 6 {
-		return false, fmt.Errorf("%w: missing header", errTTInvalidLocations)
+		return false, fmt.Errorf("%w: missing header", ErrTTInvalidLocations)
 	}
 	count := int(binary.BigEndian.Uint16(maxp[4:]))
 	width := 2
@@ -43,10 +43,10 @@ func normalizeTrueTypeLocations(tables map[string][]byte) (bool, error) {
 	case 1:
 		width = 4
 	default:
-		return false, fmt.Errorf("%w: format", errTTInvalidLocations)
+		return false, fmt.Errorf("%w: format", ErrTTInvalidLocations)
 	}
 	if count == 0 || len(loca) < (count+1)*width {
-		return false, fmt.Errorf("%w: truncated index", errTTInvalidLocations)
+		return false, fmt.Errorf("%w: truncated index", ErrTTInvalidLocations)
 	}
 	location := func(i int) uint64 {
 		if width == 2 {
@@ -58,7 +58,7 @@ func normalizeTrueTypeLocations(tables map[string][]byte) (bool, error) {
 	for i := range count + 1 {
 		offset := location(i)
 		if offset > uint64(len(glyf)) {
-			return false, fmt.Errorf("%w: offset %d outside table", errTTInvalidLocations, i)
+			return false, fmt.Errorf("%w: offset %d outside table", ErrTTInvalidLocations, i)
 		}
 		ordered = ordered && previous <= offset
 		previous = offset
@@ -83,31 +83,31 @@ func normalizeTrueTypeLocations(tables map[string][]byte) (bool, error) {
 			continue
 		}
 		if _, duplicate := bodies[start]; duplicate {
-			return false, fmt.Errorf("%w: ambiguous shared offset %d", errTTInvalidLocations, start)
+			return false, fmt.Errorf("%w: ambiguous shared offset %d", ErrTTInvalidLocations, start)
 		}
 		index, _ := slices.BinarySearch(physical, start)
 		if index+1 >= len(physical) {
-			return false, fmt.Errorf("%w: missing glyph %d body", errTTInvalidLocations, id)
+			return false, fmt.Errorf("%w: missing glyph %d body", ErrTTInvalidLocations, id)
 		}
 		data := glyf[start:physical[index+1]]
 		size, refs, err := trueTypeGlyphSize(data, count)
 		if err != nil {
-			return false, fmt.Errorf("%w: glyph %d: %w", errTTInvalidLocations, id, err)
+			return false, fmt.Errorf("%w: glyph %d: %w", ErrTTInvalidLocations, id, err)
 		}
 		if len(data)-size > 3 || len(bytes.Trim(data[size:], "\x00")) != 0 {
-			return false, fmt.Errorf("%w: ambiguous glyph %d padding", errTTInvalidLocations, id)
+			return false, fmt.Errorf("%w: ambiguous glyph %d padding", ErrTTInvalidLocations, id)
 		}
 		bodies[start], components[id] = data[:size], refs
 		total += (uint64(size) + 3) &^ 3
 		if total > uint64(^uint(0)>>1) || total > uint64(^uint32(0)) {
-			return false, fmt.Errorf("%w: rebuilt table exceeds capacity", errTTInvalidLocations)
+			return false, fmt.Errorf("%w: rebuilt table exceeds capacity", ErrTTInvalidLocations)
 		}
 	}
 	state := make([]uint8, count)
 	var visit func(int) error
 	visit = func(id int) error {
 		if state[id] == 1 {
-			return fmt.Errorf("%w: cyclic component %d", errTTInvalidLocations, id)
+			return fmt.Errorf("%w: cyclic component %d", ErrTTInvalidLocations, id)
 		}
 		if state[id] == 2 {
 			return nil

internal/base/font/match.go

@@ -0,0 +1,806 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package font
+
+import (
+	"bytes"
+	"path"
+	"slices"
+	"sort"
+	"strings"
+)
+
+// 字体匹配按精确、部分和模糊匹配排列，零值表示未匹配
+const (
+	MatchNone = iota
+	MatchExact
+	MatchPartial
+	MatchFuzzy
+)
+
+// matchRules 保存常用字体的名称、文件名及系统字体匹配规则
+var matchRules = normalizeMatchRules([]matchRule{
+	{
+		Keys:            []string{"小标宋", "方正小标宋", "xiaobiaosong", "fzxiaobiaosong", "fzxbs"},
+		Names:           []string{"小标宋体", "方正小标宋简体", "FZXiaoBiaoSong-B05", "FZXiaoBiaoSong-B05S"},
+		Files:           []string{"FZXBSJW.TTF", "fzxbs*.ttf", "fzxiaobiaosong*.ttf", "xiaobiaosong*.ttf"},
+		System:          "FZXiaoBiaoSong-B05S",
+		NoSyntheticBold: true,
+	},
+	{
+		Keys:   []string{"宋体", "新宋体", "simsun", "nsimsun", "simsunextb", "song", "songti", "stsong", "书宋", "方正书宋"},
+		Names:  []string{"宋体", "新宋体", "SimSun", "NSimSun", "SongTi", "STSong"},
+		Files:  []string{"simsun.ttc", "simsun.ttf", "nsimsun.ttf", "STSONG.TTF"},
+		System: "SimSun",
+	},
+	{
+		Keys:   []string{"黑体", "hei", "simhei", "heiti", "sthei", "方正黑体"},
+		Names:  []string{"黑体", "SimHei", "HeiTi", "STHeiti", "方正黑体简体"},
+		Files:  []string{"simhei.ttf", "STXIHEI.TTF", "FZHT_GB18030.TTF", "fzht*.ttf"},
+		System: "SimHei",
+	},
+	{
+		Keys:   []string{"楷体", "kai", "kaiti", "simkai", "stkaiti", "方正楷体"},
+		Names:  []string{"楷体", "KaiTi", "SimKai", "STKaiti", "方正楷体简体"},
+		Files:  []string{"simkai.ttf", "kaiti.ttf", "STKAITI.TTF", "FZKTJ.TTF", "fzkai*.ttf", "fzkt*.ttf"},
+		System: "KaiTi",
+	},
+	{
+		Keys:   []string{"仿宋", "fang", "fangsong", "simfang", "stfangsong", "方正仿宋"},
+		Names:  []string{"仿宋", "FangSong", "SimFang", "STFangsong", "方正仿宋简体"},
+		Files:  []string{"simfang.ttf", "fangsong.ttf", "STFANGSO.TTF", "FZFSJ.TTF", "fzfs*.ttf"},
+		System: "FangSong",
+	},
+	{
+		Keys:   []string{"微软雅黑", "microsoftyahei", "yahei", "msyh"},
+		Names:  []string{"微软雅黑", "Microsoft YaHei", "YaHei", "MSYH"},
+		Files:  []string{"msyh.ttc", "msyh.ttf"},
+		System: "Microsoft YaHei",
+	},
+	{
+		Keys:   []string{"arialblack"},
+		Names:  []string{"Arial Black", "ArialBlack"},
+		Files:  []string{"ariblk.ttf", "arial black*.ttf", "arialblack*.ttf"},
+		System: "Arial Black",
+	},
+	{
+		Keys:   []string{"arial"},
+		Names:  []string{"Arial"},
+		Files:  []string{"arial.ttf", "arial*.ttf"},
+		System: "Arial",
+	},
+	{
+		Keys:   []string{"helvetica"},
+		Names:  []string{"Helvetica", "Arial"},
+		Files:  []string{"arial.ttf", "arial*.ttf"},
+		System: "Arial",
+	},
+	{
+		Keys:   []string{"couriernew", "courier"},
+		Names:  []string{"Courier New", "CourierNew", "Courier"},
+		Files:  []string{"cour.ttf", "courier new*.ttf", "courier*.ttf"},
+		System: "Courier New",
+	},
+	{
+		Keys:   []string{"segoeui"},
+		Names:  []string{"Segoe UI", "SegoeUI"},
+		Files:  []string{"segoeui.ttf", "segoe*.ttf"},
+		System: "Segoe UI",
+	},
+	{
+		Keys:   []string{"timesnewroman", "times"},
+		Names:  []string{"Times New Roman", "TimesNewRoman"},
+		Files:  []string{"times.ttf", "times new roman*.ttf", "times*.ttf"},
+		System: "Times New Roman",
+	},
+})
+
+// fontNameReplacer 移除字体名称匹配时忽略的分隔符
+var fontNameReplacer = strings.NewReplacer(" ", "", "-", "", "_", "", "(", "", ")", "", "（", "", "）", "")
+
+// matchRule 字体匹配规则
+type matchRule struct {
+	Keys            []string
+	Names           []string
+	Files           []string
+	System          string
+	NoSyntheticBold bool
+}
+
+// FileCandidate 字体文件候选
+type FileCandidate struct {
+	Name       string
+	Face       int
+	base       string
+	lowerBase  string
+	filename   string
+	normalized string
+	names      []string
+	fold       string
+}
+
+// patternMatcher 字体文件匹配器
+type patternMatcher struct {
+	pattern      string
+	lowerPattern string
+	stem         string
+	aliases      []string
+	priority     int
+}
+
+// FileMatch 字体文件匹配结果
+type FileMatch struct {
+	Name      string
+	Face      int
+	Priority  int
+	Rank      int
+	styleRank int
+	sortName  string
+}
+
+// fileKey 字体文件与集合索引的去重键
+type fileKey struct {
+	Name string
+	Face int
+}
+
+// NormalizeName 规范化字体名称
+// 入参: name 字体名称
+// 返回: string 规范化后的字体名称
+func NormalizeName(name string) string {
+	name = strings.ReplaceAll(name, "\\", "/")
+	name = path.Base(strings.TrimSpace(name))
+	if IsFontFileName(name) {
+		name = strings.TrimSuffix(name, path.Ext(name))
+	}
+	name = strings.ToLower(strings.TrimSpace(name))
+	return fontNameReplacer.Replace(name)
+}
+
+// IsFontFileName 判断是否为字体文件名
+// 入参: name 文件名
+// 返回: bool 是否为字体文件
+func IsFontFileName(name string) bool {
+	switch strings.ToLower(path.Ext(name)) {
+	case ".ttf", ".otf", ".ttc", ".otc":
+		return true
+	default:
+		return false
+	}
+}
+
+// AppendFontName 追加字体名称
+// 入参: names 字体名称列表, seen 去重映射, name 字体名称
+// 返回: []string 字体名称列表
+func AppendFontName(names []string, seen map[string]bool, name string) []string {
+	name = strings.TrimSpace(name)
+	if name == "" {
+		return names
+	}
+	key := NormalizeName(name)
+	if key == "" || seen[key] {
+		return names
+	}
+	seen[key] = true
+	return append(names, name)
+}
+
+// normalizeMatchRules 预处理固定字体规则的匹配名称，保留候选名称及顺序
+// 入参: rules 字体匹配规则
+// 返回: []matchRule 预处理后的规则
+func normalizeMatchRules(rules []matchRule) []matchRule {
+	for i := range rules {
+		rule := &rules[i]
+		keys := append(append(rule.Keys, rule.Names...), rule.System)
+		rule.Keys = nil
+		for _, key := range keys {
+			key = NormalizeName(key)
+			if key != "" && !slices.Contains(rule.Keys, key) {
+				rule.Keys = append(rule.Keys, key)
+			}
+		}
+	}
+	return rules
+}
+
+// CandidateNames 获取字体候选名称
+// 入参: names 字体名称列表
+// 返回: []string 字体候选名称
+func CandidateNames(names ...string) []string {
+	return candidateNamesByLevel(MatchFuzzy, names...)
+}
+
+// ExactCandidateNames 获取精确字体候选名称
+// 入参: names 字体名称列表
+// 返回: []string 精确字体候选名称
+func ExactCandidateNames(names ...string) []string {
+	return candidateNamesByLevel(MatchExact, names...)
+}
+
+// qualifiedNames 获取保留名称后缀的字体候选
+// 入参: name 字体名称
+// 返回: []string 保留后缀的候选名称
+func qualifiedNames(name string) []string {
+	name = NormalizeName(name)
+	key := NormalizeName(name)
+	var names []string
+	seen := make(map[string]bool)
+	for _, rule := range matchRules {
+		if ruleMatchLevel(rule, key) != MatchPartial {
+			continue
+		}
+		prefix := ""
+		for _, alias := range rule.Keys {
+			if len(alias) > len(prefix) && strings.HasPrefix(name, alias) {
+				prefix = alias
+			}
+		}
+		suffix := strings.TrimPrefix(name, prefix)
+		for _, alias := range append([]string{rule.System}, rule.Names...) {
+			names = AppendFontName(names, seen, NormalizeName(alias)+suffix)
+		}
+	}
+	return names
+}
+
+// candidateNamesByLevel 获取指定等级内的字体候选名称
+// 入参: maxLevel 最大匹配等级, names 字体名称列表
+// 返回: []string 字体候选名称
+func candidateNamesByLevel(maxLevel int, names ...string) []string {
+	var result []string
+	seen := make(map[string]bool)
+	var bases []string
+	for _, name := range names {
+		name = strings.TrimSpace(name)
+		if name == "" {
+			continue
+		}
+		result = AppendFontName(result, seen, name)
+		bases = append(bases, name)
+	}
+	levels := matchLevels(bases)
+	for level := MatchExact; level <= maxLevel; level++ {
+		for i := range bases {
+			for j, rule := range matchRules {
+				if levels[i*len(matchRules)+j] == level {
+					result = AppendFontName(result, seen, rule.System)
+					for _, item := range rule.Names {
+						result = AppendFontName(result, seen, item)
+					}
+				}
+			}
+		}
+	}
+	return result
+}
+
+// patternStem 获取字体匹配模式主干
+// 入参: pattern 字体文件匹配模式
+// 返回: string 字体匹配模式主干
+func patternStem(pattern string) string {
+	stem := strings.TrimSuffix(pattern, "*")
+	if IsFontFileName(stem) {
+		stem = strings.TrimSuffix(stem, path.Ext(stem))
+	}
+	if index := strings.IndexAny(stem, "*?["); index >= 0 {
+		stem = stem[:index]
+	}
+	return NormalizeName(stem)
+}
+
+// FilePatterns 获取字体文件匹配模式
+// 入参: names 字体名称列表
+// 返回: []string 字体文件匹配模式
+func FilePatterns(names ...string) []string {
+	var result []string
+	seen := make(map[string]bool)
+	levels := matchLevels(names)
+	for level := MatchExact; level <= MatchFuzzy; level++ {
+		for _, name := range candidateNamesAtLevel(level, names, levels) {
+			result = appendPattern(result, seen, name+"*")
+		}
+		for i := range names {
+			for j, rule := range matchRules {
+				if levels[i*len(matchRules)+j] == level {
+					for _, item := range rule.Files {
+						result = appendPattern(result, seen, item)
+					}
+				}
+			}
+		}
+	}
+	return result
+}
+
+// SystemNames 获取系统字体名称
+// 入参: names 字体名称列表
+// 返回: []string 系统字体名称
+func SystemNames(names ...string) []string {
+	var result []string
+	seen := make(map[string]bool)
+	for _, name := range names {
+		for _, item := range candidateNamesByLevel(MatchPartial, name) {
+			result = AppendFontName(result, seen, item)
+		}
+	}
+	return result
+}
+
+// candidateNamesAtLevel 获取指定等级的字体候选名称
+// 入参: level 匹配等级, names 字体名称列表, levels 名称与规则的匹配等级
+// 返回: []string 字体候选名称
+func candidateNamesAtLevel(level int, names []string, levels []int) []string {
+	var result []string
+	seen := make(map[string]bool)
+	for i, name := range names {
+		name = strings.TrimSpace(name)
+		if name == "" {
+			continue
+		}
+		if level == MatchExact {
+			result = AppendFontName(result, seen, name)
+		}
+		for j, rule := range matchRules {
+			if levels[i*len(matchRules)+j] == level {
+				result = AppendFontName(result, seen, rule.System)
+				for _, item := range rule.Names {
+					result = AppendFontName(result, seen, item)
+				}
+			}
+		}
+	}
+	return result
+}
+
+// DefaultSystemNames 获取默认系统字体名称
+// 返回: []string 默认系统字体名称
+func DefaultSystemNames() []string {
+	return []string{
+		"SimSun", "Microsoft YaHei", "SimHei", "KaiTi", "FangSong",
+		"Noto Sans CJK SC", "Source Han Sans SC", "Arial", "Segoe UI", "Times New Roman",
+	}
+}
+
+// NoSyntheticBold 判断字体是否禁用合成粗体
+// 入参: names 字体名称列表
+// 返回: bool 是否禁用合成粗体
+func NoSyntheticBold(names ...string) bool {
+	for _, name := range names {
+		name = NormalizeName(name)
+		for _, rule := range matchRules {
+			if !rule.NoSyntheticBold {
+				continue
+			}
+			level := ruleMatchLevel(rule, name)
+			if level >= MatchExact && level <= MatchPartial {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// matchLevels 按名称和规则顺序计算匹配等级
+// 入参: names 字体名称列表
+// 返回: []int 名称与规则的匹配等级
+func matchLevels(names []string) []int {
+	levels := make([]int, len(names)*len(matchRules))
+	for i, name := range names {
+		name = NormalizeName(name)
+		for j, rule := range matchRules {
+			levels[i*len(matchRules)+j] = ruleMatchLevel(rule, name)
+		}
+	}
+	return levels
+}
+
+// ruleMatchLevel 获取字体规则匹配等级
+// 入参: rule 字体匹配规则, name 规范化后的字体名称
+// 返回: int 匹配等级
+func ruleMatchLevel(rule matchRule, name string) int {
+	if name == "" {
+		return MatchNone
+	}
+	level := MatchNone
+	for _, item := range rule.Keys {
+		if name == item {
+			return MatchExact
+		}
+		if strings.HasPrefix(name, item) {
+			level = MatchPartial
+		} else if level == MatchNone && strings.Contains(name, item) {
+			level = MatchFuzzy
+		}
+	}
+	return level
+}
+
+// appendPattern 追加字体文件匹配模式
+// 入参: patterns 匹配模式列表, seen 去重映射, pattern 匹配模式
+// 返回: []string 匹配模式列表
+func appendPattern(patterns []string, seen map[string]bool, pattern string) []string {
+	pattern = strings.TrimSpace(pattern)
+	if pattern == "" {
+		return patterns
+	}
+	key := strings.ToLower(pattern)
+	if seen[key] {
+		return patterns
+	}
+	seen[key] = true
+	return append(patterns, pattern)
+}
+
+// AppendFileNames 建立各字体的内部名称与文件别名匹配候选
+// 入参: candidates 字体候选, index 文件候选索引, faces 各字体内部名称
+// 返回: []FileCandidate 字体候选列表
+func AppendFileNames(candidates []FileCandidate, index int, faces [][]string) []FileCandidate {
+	file := candidates[index]
+	replaced := false
+	for face, names := range faces {
+		file.Face = face
+		file.names = make([]string, len(names))
+		for i, name := range names {
+			file.names[i] = NormalizeName(name)
+		}
+		for _, name := range file.names {
+			file.normalized = name
+			if !replaced {
+				candidates[index] = file
+				replaced = true
+			} else {
+				candidates = append(candidates, file)
+			}
+		}
+	}
+	return candidates
+}
+
+// CollectionIndex 按内部名称与样式选择集合项，未匹配时保留首项
+// 入参: data 集合数据, names 字体名称, bold 是否粗体, italic 是否斜体
+// 返回: int 零起始字体索引
+func CollectionIndex(data []byte, names []string, bold, italic bool) int {
+	return NameIndex(FileNames(bytes.NewReader(data)), names, bold, italic)
+}
+
+// NameIndex 按名称与样式选择字体索引，未匹配时保留首项
+// 入参: faces 各字体名称, names 目标名称, bold 是否粗体, italic 是否斜体
+// 返回: int 零起始字体索引
+func NameIndex(faces [][]string, names []string, bold, italic bool) int {
+	candidates := AppendFileNames([]FileCandidate{{}}, 0, faces)
+	if matches := FileMatches(candidates, names, bold, italic); len(matches) > 0 {
+		return matches[0].Face
+	}
+	return 0
+}
+
+// FileMatches 匹配字体文件候选
+// 入参: candidates 字体候选, names 字体名称, bold 是否粗体, italic 是否斜体
+// 返回: []FileMatch 按优先级排列的字体匹配
+func FileMatches(candidates []FileCandidate, names []string, bold, italic bool) []FileMatch {
+	matches := make([]FileMatch, 0, len(candidates))
+	seen := make(map[fileKey]int, len(candidates))
+	if len(names) == 0 {
+		for _, name := range DefaultSystemNames() {
+			matches = append(matches, FileMatches(candidates, []string{name}, bold, italic)...)
+		}
+		sort.SliceStable(matches, func(i, j int) bool {
+			return matches[i].Rank < matches[j].Rank
+		})
+		unique := matches[:0]
+		for _, match := range matches {
+			key := fileKey{strings.ToLower(match.Name), match.Face}
+			if _, ok := seen[key]; !ok {
+				seen[key] = len(unique)
+				unique = append(unique, match)
+			}
+		}
+		return unique
+	}
+	for i, name := range names {
+		if name == "" {
+			continue
+		}
+		for j, alias := range append([]string{name}, qualifiedNames(name)...) {
+			matcher := patternMatcher{stem: NormalizeName(alias), priority: (i-len(names))*2 + min(j, 1)}
+			if matcher.stem == "" {
+				continue
+			}
+			for _, file := range candidates {
+				if rank := matcher.rankCandidate(file); rank == MatchExact {
+					appendFileMatch(&matches, seen, matcher, file, rank, bold, italic)
+				}
+			}
+		}
+	}
+	for _, matcher := range newPatternMatchers(FilePatterns(names...)) {
+		for _, file := range candidates {
+			rank := matcher.rankCandidate(file)
+			appendFileMatch(&matches, seen, matcher, file, rank, bold, italic)
+		}
+	}
+	sortFileMatches(matches)
+	return matches
+}
+
+// FileCandidates 筛选字体文件候选
+// 入参: names 文件名列表, base 文件名提取函数
+// 返回: []FileCandidate 字体文件候选列表
+func FileCandidates(names []string, base func(string) string) []FileCandidate {
+	files := make([]FileCandidate, 0, len(names))
+	for _, name := range names {
+		if IsFontFileName(name) {
+			baseName := base(name)
+			normalized := NormalizeName(strings.TrimSuffix(baseName, path.Ext(baseName)))
+			files = append(files, FileCandidate{
+				Name:       name,
+				base:       baseName,
+				lowerBase:  strings.ToLower(baseName),
+				filename:   normalized,
+				normalized: normalized,
+				fold:       strings.ToLower(name),
+			})
+		}
+	}
+	return files
+}
+
+// newPatternMatcher 创建字体文件匹配器
+// 入参: pattern 匹配模式
+// 返回: patternMatcher 字体文件匹配器
+func newPatternMatcher(pattern string) patternMatcher {
+	matcher := patternMatcher{
+		pattern:      pattern,
+		lowerPattern: strings.ToLower(pattern),
+		stem:         patternStem(pattern),
+	}
+	if matcher.stem != "" {
+		for _, alias := range ExactCandidateNames(matcher.stem) {
+			alias = NormalizeName(alias)
+			if alias != "" {
+				matcher.aliases = append(matcher.aliases, alias)
+			}
+		}
+	}
+	return matcher
+}
+
+// newPatternMatchers 创建字体文件匹配器列表
+// 入参: patterns 匹配模式列表
+// 返回: []patternMatcher 字体文件匹配器列表
+func newPatternMatchers(patterns []string) []patternMatcher {
+	matchers := make([]patternMatcher, 0, len(patterns))
+	for priority, pattern := range patterns {
+		matcher := newPatternMatcher(pattern)
+		matcher.priority = priority
+		matchers = append(matchers, matcher)
+	}
+	return matchers
+}
+
+// rankCandidate 获取字体文件候选匹配等级
+// 入参: file 字体文件候选
+// 返回: int 匹配等级
+func (m patternMatcher) rankCandidate(file FileCandidate) int {
+	exactPath, _ := path.Match(m.pattern, file.base)
+	lowerPath, _ := path.Match(m.lowerPattern, file.lowerBase)
+	if m.stem == "" {
+		if exactPath || lowerPath {
+			return MatchFuzzy
+		}
+		return MatchNone
+	}
+	name := m.candidateName(file)
+	if name == m.stem {
+		return MatchExact
+	}
+	for _, alias := range m.aliases {
+		if name == alias {
+			return MatchExact
+		}
+	}
+	if fileKnownStyleSuffix(m.styleSuffixNormalized(name)) {
+		return MatchExact
+	}
+	if strings.HasPrefix(name, m.stem) {
+		return MatchPartial
+	}
+	for _, alias := range m.aliases {
+		if strings.HasPrefix(name, alias) {
+			return MatchPartial
+		}
+	}
+	if exactPath || lowerPath || strings.Contains(name, m.stem) {
+		return MatchFuzzy
+	}
+	for _, alias := range m.aliases {
+		if strings.Contains(name, alias) {
+			return MatchFuzzy
+		}
+	}
+	return MatchNone
+}
+
+// candidateName 保留同族内部名称的区分，只有无关联时使用调用方文件别名
+// 入参: file 字体文件候选
+// 返回: string 用于统一匹配名称与样式的规范名称
+func (m patternMatcher) candidateName(file FileCandidate) string {
+	if len(file.names) == 0 || file.base == "" || m.stem == "" {
+		return file.normalized
+	}
+	for _, name := range file.names {
+		if strings.HasPrefix(name, m.stem) {
+			return file.normalized
+		}
+		for _, alias := range m.aliases {
+			if strings.HasPrefix(name, alias) {
+				return file.normalized
+			}
+		}
+	}
+	return file.filename
+}
+
+// styleSuffixNormalized 获取规范字体名称的样式后缀
+// 入参: name 规范字体名称
+// 返回: string 样式后缀
+func (m patternMatcher) styleSuffixNormalized(name string) string {
+	if m.stem == "" || name == "" {
+		return ""
+	}
+	if strings.HasPrefix(name, m.stem) {
+		return strings.TrimPrefix(name, m.stem)
+	}
+	for _, alias := range m.aliases {
+		if strings.HasPrefix(name, alias) {
+			return strings.TrimPrefix(name, alias)
+		}
+	}
+	return ""
+}
+
+// appendFileMatch 追加字体文件匹配结果
+// 入参: matches 匹配结果, seen 已匹配文件, matcher 匹配器, file 字体文件候选, rank 匹配等级, bold 是否粗体, italic 是否斜体
+func appendFileMatch(matches *[]FileMatch, seen map[fileKey]int, matcher patternMatcher, file FileCandidate, rank int, bold, italic bool) {
+	if rank == MatchNone {
+		return
+	}
+	suffix := matcher.styleSuffixNormalized(matcher.candidateName(file))
+	if rank == MatchFuzzy {
+		suffix = matcher.styleSuffixNormalized(NormalizeName(file.base))
+	}
+	next := FileMatch{
+		Name:      file.Name,
+		Face:      file.Face,
+		Priority:  matcher.priority,
+		Rank:      rank,
+		styleRank: fileStyleRank(suffix, bold, italic),
+		sortName:  file.lowerBase,
+	}
+	key := fileKey{file.fold, file.Face}
+	if index, ok := seen[key]; ok {
+		if fileMatchLess(next, (*matches)[index]) {
+			(*matches)[index] = next
+		}
+		return
+	}
+	seen[key] = len(*matches)
+	*matches = append(*matches, next)
+}
+
+// sortFileMatches 排序字体文件匹配结果
+// 入参: matches 匹配结果
+func sortFileMatches(matches []FileMatch) {
+	sort.SliceStable(matches, func(i, j int) bool {
+		return fileMatchLess(matches[i], matches[j])
+	})
+}
+
+// fileMatchLess 判断字体文件匹配结果优先级
+// 入参: left 左侧匹配结果, right 右侧匹配结果
+// 返回: bool 左侧是否优先
+func fileMatchLess(left, right FileMatch) bool {
+	if left.Priority != right.Priority {
+		return left.Priority < right.Priority
+	}
+	if left.Rank != right.Rank {
+		return left.Rank < right.Rank
+	}
+	if left.styleRank != right.styleRank {
+		return left.styleRank < right.styleRank
+	}
+	return left.sortName < right.sortName
+}
+
+// FileMatchNames 获取字体文件匹配名称
+// 入参: matches 匹配结果
+// 返回: []string 字体文件列表
+func FileMatchNames(matches []FileMatch) []string {
+	names := make([]string, 0, len(matches))
+	seen := make(map[string]bool, len(matches))
+	for _, match := range matches {
+		key := strings.ToLower(match.Name)
+		if !seen[key] {
+			seen[key] = true
+			names = append(names, match.Name)
+		}
+	}
+	return names
+}
+
+// fileStyleRank 获取字体文件样式匹配等级
+// 入参: suffix 样式后缀, bold 是否粗体, italic 是否斜体
+// 返回: int 样式匹配等级
+func fileStyleRank(suffix string, bold, italic bool) int {
+	fileBold, fileItalic := fileStyleFromSuffix(suffix)
+	rank := 0
+	if fileBold != bold {
+		rank += 2
+	}
+	if fileItalic != italic {
+		rank += 2
+	}
+	if !bold && !italic && !fileBold && !fileItalic && suffix != "" && !fileRegularSuffix(suffix) {
+		rank++
+	}
+	return rank
+}
+
+// fileStyleFromSuffix 获取样式后缀对应的字体样式
+// 入参: suffix 样式后缀
+// 返回: bool 是否粗体, bool 是否斜体
+func fileStyleFromSuffix(suffix string) (bool, bool) {
+	bold := suffix == "b" ||
+		suffix == "bd" ||
+		suffix == "bold" ||
+		suffix == "bi" ||
+		suffix == "bolditalic" ||
+		suffix == "boldoblique"
+	italic := suffix == "i" ||
+		suffix == "it" ||
+		suffix == "italic" ||
+		suffix == "oblique" ||
+		suffix == "bi" ||
+		suffix == "bolditalic" ||
+		suffix == "boldoblique"
+	return bold, italic
+}
+
+// fileRegularSuffix 判断是否为常规样式后缀
+// 入参: suffix 样式后缀
+// 返回: bool 是否为常规样式后缀
+func fileRegularSuffix(suffix string) bool {
+	switch suffix {
+	case "r", "regular", "normal", "常规":
+		return true
+	default:
+		return false
+	}
+}
+
+// fileKnownStyleSuffix 判断是否为已知样式后缀
+// 入参: suffix 样式后缀
+// 返回: bool 是否为已知样式后缀
+func fileKnownStyleSuffix(suffix string) bool {
+	switch suffix {
+	case "r", "regular", "normal", "常规",
+		"b", "bd", "bold",
+		"i", "it", "italic", "oblique",
+		"bi", "bolditalic", "boldoblique":
+		return true
+	default:
+		return false
+	}
+}

internal/base/font/metrics.go

@@ -0,0 +1,24 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package font
+
+// glyphPather 接收字体设计坐标中的轮廓指令
+type glyphPather interface {
+	MoveTo(float64, float64)
+	LineTo(float64, float64)
+	QuadTo(float64, float64, float64, float64)
+	CubeTo(float64, float64, float64, float64, float64, float64)
+	Close()
+}

internal/base/font/name.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package font
 
 import (
 	"bytes"
@@ -33,35 +33,10 @@ type fontNameRecord struct {
 	Offset   uint16
 }
 
-// appendFontFileNames 建立各字体的内部名称与文件别名匹配候选
-// 入参: candidates 字体候选, index 文件候选索引, faces 各字体内部名称
-// 返回: []fontFileCandidate 字体候选列表
-func appendFontFileNames(candidates []fontFileCandidate, index int, faces [][]string) []fontFileCandidate {
-	file := candidates[index]
-	replaced := false
-	for face, names := range faces {
-		file.face = face
-		file.names = make([]string, len(names))
-		for i, name := range names {
-			file.names[i] = fontNormalizeName(name)
-		}
-		for _, name := range file.names {
-			file.normalized = name
-			if !replaced {
-				candidates[index] = file
-				replaced = true
-			} else {
-				candidates = append(candidates, file)
-			}
-		}
-	}
-	return candidates
-}
-
-// fontFileNames 按字体索引读取字体或集合中各项的名称
+// FileNames 按字体索引读取字体或集合中各项的名称
 // 入参: file 字体数据
 // 返回: [][]string 各字体名称及带样式的字体族名称
-func fontFileNames(file io.ReaderAt) [][]string {
+func FileNames(file io.ReaderAt) [][]string {
 	var header [12]byte
 	if _, err := file.ReadAt(header[:], 0); err != nil {
 		return nil
@@ -84,24 +59,6 @@ func fontFileNames(file io.ReaderAt) [][]string {
 	return faces
 }
 
-// fontCollectionIndex 按内部名称与样式选择集合项，未匹配时保留首项
-// 入参: data 集合数据, names 字体名称, bold 是否粗体, italic 是否斜体
-// 返回: int 零起始字体索引
-func fontCollectionIndex(data []byte, names []string, bold, italic bool) int {
-	return fontNameIndex(fontFileNames(bytes.NewReader(data)), names, bold, italic)
-}
-
-// fontNameIndex 按名称与样式选择字体索引，未匹配时保留首项
-// 入参: faces 各字体名称, names 目标名称, bold 是否粗体, italic 是否斜体
-// 返回: int 零起始字体索引
-func fontNameIndex(faces [][]string, names []string, bold, italic bool) int {
-	candidates := appendFontFileNames([]fontFileCandidate{{}}, 0, faces)
-	if matches := fontFileMatches(candidates, names, bold, italic); len(matches) > 0 {
-		return matches[0].face
-	}
-	return 0
-}
-
 // fontFaceNames 读取指定字体表目录中的名称
 // 入参: file 字体数据, offset 字体表目录偏移
 // 返回: []string 字体名称及带样式的字体族名称
@@ -129,16 +86,23 @@ func fontFaceNames(file io.ReaderAt, offset int64) []string {
 		if err != nil {
 			return nil
 		}
-		return fontNamesFromTable(data)
+		return NamesFromTable(data)
 	}
 	return nil
 }
 
-// fontNamesFromTable 解析字体名称表
+// NamesFromTable 解析字体名称表
 // 入参: data 名称表数据
 // 返回: []string 字体名称列表
-func fontNamesFromTable(data []byte) []string {
+func NamesFromTable(data []byte) []string {
 	records, values := fontNameValues(data)
+	return fontNamesFromValues(records, values)
+}
+
+// fontNamesFromValues 从已解码记录生成去重名称，保留原有顺序及样式匹配
+// 入参: records 名称记录, values 已解码的名称文本
+// 返回: []string 字体名称列表
+func fontNamesFromValues(records []fontNameRecord, values map[[4]uint16]string) []string {
 	var names []string
 	seen := make(map[string]bool)
 	for _, record := range records {
@@ -154,7 +118,7 @@ func fontNamesFromTable(data []byte) []string {
 		default:
 			continue
 		}
-		names = appendFontName(names, seen, name)
+		names = AppendFontName(names, seen, name)
 	}
 	return names
 }
@@ -178,7 +142,7 @@ func fontNameValues(data []byte) ([]fontNameRecord, map[[4]uint16]string) {
 	values := make(map[[4]uint16]string)
 	for _, record := range records {
 		switch record.Name {
-		case 1, 2, 4, 6, 16, 17:
+		case 1, 2, 4, 5, 6, 8, 16, 17:
 		default:
 			continue
 		}

internal/base/font/repair.go

@@ -0,0 +1,73 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package font
+
+import (
+	"encoding/binary"
+)
+
+// FixDataAggressive 激进修复字体数据
+// 尝试修复缺失表(OS/2, cmap等)的TrueType字体或包装CFF裸数据
+// 对显式字形映射补充私有字符cmap，便于按glyph id渲染
+// 入参: data 原始字体数据, fixCmap 是否修复cmap, fixName 是否修复name
+// 返回: bool 是否修复, []byte 修复后数据, map[rune]uint16 字符映射, bool 是否缺失cmap, error 错误信息
+func FixDataAggressive(data []byte, fixCmap, fixName bool) (bool, []byte, map[rune]uint16, bool, error) {
+	if len(data) < 4 {
+		return false, data, nil, false, nil
+	}
+	tag := string(data[0:4])
+	u32Tag := binary.BigEndian.Uint32(data[0:4])
+	isTrueType := u32Tag == 0x00010000 || tag == "true"
+	isOpenType := tag == "OTTO"
+	isTTC := tag == "ttcf"
+	if isTTC {
+		return false, data, nil, false, nil
+	}
+	if isBareCFFData(data) {
+		otf, mapping, err := WrapCFFToOTF(data)
+		if err != nil {
+			return false, data, nil, false, err
+		}
+		return true, otf, mapping, false, nil
+	}
+	if !isTrueType && !isOpenType {
+		return false, data, nil, false, nil
+	}
+	fixed, newData, mapping, mc, err := fixTrueType(data, fixCmap, fixName)
+	return fixed, newData, mapping, mc, err
+}
+
+// SFNTData 保留字体原始表数据和时间，重新计算目录与校验和
+// 入参: tables 原始字体表
+// 返回: []byte 独立SFNT数据
+func SFNTData(tables map[string][]byte) []byte {
+	data, _ := SerializeOTF(tables)
+	return data
+}
+
+// isBareCFFData 检查是否为CFF裸字体数据
+// 入参: data 字体数据
+// 返回: bool 是否为CFF裸数据
+func isBareCFFData(data []byte) bool {
+	if len(data) < 4 {
+		return false
+	}
+	if data[0] != 1 || data[1] != 0 {
+		return false
+	}
+	hdrSize := int(data[2])
+	offSize := int(data[3])
+	return 4 <= hdrSize && hdrSize <= len(data) && 1 <= offSize && offSize <= 4
+}

internal/base/font/sfnt.go

@@ -0,0 +1,460 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package font
+
+import (
+	"encoding/binary"
+	"fmt"
+	"iter"
+	"maps"
+	"slices"
+	"sync"
+	"unicode/utf8"
+
+	"github.com/go-text/typesetting/font/opentype/tables"
+)
+
+// SFNT 保存独立字体表和基础度量，不包含绘图库对象
+type SFNT struct {
+	Tables                             map[string][]byte
+	IsTrueType, IsCFF                  bool
+	cmaps                              []sfntCmap
+	units, count, horizontal, vertical uint16
+	reverseOnce                        sync.Once
+	reverse                            map[uint16][]rune
+}
+
+// sfntCmap 保存编码记录及字符映射，连续区间与共享子表不重复展开
+type sfntCmap struct {
+	platform, encoding, format uint16
+	mapping                    map[rune]uint16
+	groups                     []byte
+	entries                    uint64
+	duplicate                  bool
+}
+
+// ParseSFNT 校验独立字体的必需表、度量范围及字符映射
+// 入参: data 独立SFNT数据
+// 返回: *SFNT 字体, error 格式错误
+func ParseSFNT(data []byte) (*SFNT, error) {
+	table, err := FileTables(data, 0)
+	if err != nil {
+		return nil, err
+	}
+	return ParseSFNTTables(table)
+}
+
+// ParseSFNTTables 校验字体表并解析度量和字符映射，借用表数据且不修改其内容
+// 入参: table 字体表
+// 返回: *SFNT 字体, error 格式错误
+func ParseSFNTTables(table map[string][]byte) (*SFNT, error) {
+	head, maxp, hhea := table["head"], table["maxp"], table["hhea"]
+	if len(head) != 54 || len(maxp) < 6 || len(hhea) < 36 {
+		return nil, fmt.Errorf("missing or truncated font metrics")
+	}
+	f := &SFNT{Tables: maps.Clone(table), IsTrueType: table["glyf"] != nil, IsCFF: table["CFF "] != nil}
+	f.units, f.count = binary.BigEndian.Uint16(head[18:]), binary.BigEndian.Uint16(maxp[4:])
+	f.horizontal = binary.BigEndian.Uint16(hhea[34:])
+	if f.units < 16 || f.units > 16384 || f.count == 0 || f.IsTrueType == f.IsCFF || !validSFNTMetrics(table["hmtx"], f.count, f.horizontal) {
+		return nil, fmt.Errorf("invalid font outlines or horizontal metrics")
+	}
+	if vhea := table["vhea"]; vhea != nil {
+		if len(vhea) < 36 {
+			return nil, fmt.Errorf("truncated vertical metrics header")
+		}
+		f.vertical = binary.BigEndian.Uint16(vhea[34:])
+		if !validSFNTMetrics(table["vmtx"], f.count, f.vertical) {
+			return nil, fmt.Errorf("invalid vertical metrics")
+		}
+	}
+	if f.IsTrueType {
+		format := binary.BigEndian.Uint16(head[50:])
+		if format > 1 || len(table["loca"]) < (int(f.count)+1)*(2+2*int(format)) {
+			return nil, fmt.Errorf("invalid glyph location table")
+		}
+	}
+	cmaps, err := readSFNTCmaps(table["cmap"])
+	if err != nil {
+		return nil, err
+	}
+	f.cmaps = cmaps
+	for _, cmap := range f.cmaps {
+		if cmap.duplicate {
+			continue
+		}
+		for _, glyph := range cmap.pairs() {
+			if glyph >= f.count {
+				return nil, fmt.Errorf("cmap glyph index out of range")
+			}
+		}
+	}
+	return f, nil
+}
+
+// validSFNTMetrics 校验完整度量记录和末尾边距数组的范围
+// 入参: data 度量表, count 字形数, metrics 完整度量记录数
+// 返回: bool 是否有效
+func validSFNTMetrics(data []byte, count, metrics uint16) bool {
+	return metrics != 0 && metrics <= count && len(data) >= int(metrics)*4+int(count-metrics)*2
+}
+
+// readSFNTCmaps 校验各编码子表并保留原顺序，共享子表只解析一次
+// 入参: data cmap表
+// 返回: []sfntCmap 编码记录, error 表结构错误
+func readSFNTCmaps(data []byte) ([]sfntCmap, error) {
+	data, err := NormalizeCmap(data)
+	if err != nil {
+		return nil, err
+	}
+	if _, _, err := tables.ParseCmap(data); err != nil {
+		return nil, err
+	}
+	count := int(binary.BigEndian.Uint16(data[2:]))
+	result := make([]sfntCmap, 0, count)
+	parsed := make(map[uint32]sfntCmap)
+	for i := range count {
+		record := data[4+8*i:]
+		offset := binary.BigEndian.Uint32(record[4:])
+		if uint64(offset)+2 > uint64(len(data)) {
+			return nil, fmt.Errorf("invalid cmap offset")
+		}
+		sub := data[offset:]
+		format := binary.BigEndian.Uint16(sub)
+		cmap, found := parsed[offset]
+		if !found {
+			cmap.mapping = make(map[rune]uint16)
+			var err error
+			switch format {
+			case 0:
+				parseCmapFormat0(sub, cmap.mapping)
+			case 4:
+				parseCmapFormat4(sub, cmap.mapping)
+			case 6:
+				parseCmapFormat6(sub, cmap.mapping)
+			case 12:
+				if len(sub) >= 16 {
+					length := uint64(binary.BigEndian.Uint32(sub[4:]))
+					count := uint64(binary.BigEndian.Uint32(sub[12:]))
+					if length >= 16 && length <= uint64(len(sub)) && count <= (length-16)/12 {
+						cmap.groups = sub[16 : 16+12*count]
+						for offset := 0; offset < len(cmap.groups); offset += 12 {
+							first := binary.BigEndian.Uint32(cmap.groups[offset:])
+							last := binary.BigEndian.Uint32(cmap.groups[offset+4:])
+							if first > last || offset != 0 && first <= binary.BigEndian.Uint32(cmap.groups[offset-8:]) {
+								cmap.groups = nil
+								parseCmapFormat12(sub, cmap.mapping)
+								break
+							}
+						}
+						if cmap.groups != nil {
+							cmap.mapping = nil
+							for range cmap.pairs() {
+								cmap.entries++
+							}
+						}
+					}
+				}
+			case 2:
+				cmap.mapping, err = parseCmapFormat2(sub)
+			case 8, 10, 13:
+				cmap.mapping, err = parseCmapExtended(sub)
+			case 14:
+			default:
+				return nil, fmt.Errorf("unsupported cmap format %d", format)
+			}
+			if err != nil {
+				return nil, err
+			}
+			parsed[offset] = cmap
+		}
+		cmap.platform, cmap.encoding, cmap.format, cmap.duplicate = binary.BigEndian.Uint16(record), binary.BigEndian.Uint16(record[2:]), format, found
+		result = append(result, cmap)
+	}
+	return result, nil
+}
+
+// pairs 按原映射返回字符与字形，连续编码段不展开存储
+// 返回: iter.Seq2[rune, uint16] 非零有效字符映射
+func (c sfntCmap) pairs() iter.Seq2[rune, uint16] {
+	return func(yield func(rune, uint16) bool) {
+		for char, glyph := range c.mapping {
+			if !yield(char, glyph) {
+				return
+			}
+		}
+		for offset := 0; offset+12 <= len(c.groups); offset += 12 {
+			group := c.groups[offset:]
+			first, last, glyph := binary.BigEndian.Uint32(group), binary.BigEndian.Uint32(group[4:]), binary.BigEndian.Uint32(group[8:])
+			if first > last || first > utf8.MaxRune || glyph > 65535 {
+				continue
+			}
+			end := min(uint64(last), uint64(first)+65535-uint64(glyph), uint64(utf8.MaxRune))
+			for char := uint64(first); char <= end; char++ {
+				id := uint16(uint64(glyph) + char - uint64(first))
+				if id != 0 && utf8.ValidRune(rune(char)) && !yield(rune(char), id) {
+					return
+				}
+			}
+		}
+	}
+}
+
+// lookup 查找原字符映射，连续编码段使用有序区间查询
+// 入参: char 字符
+// 返回: uint16 字形编号, bool 是否存在映射
+func (c sfntCmap) lookup(char rune) (uint16, bool) {
+	if glyph, ok := c.mapping[char]; ok {
+		return glyph, true
+	}
+	if !utf8.ValidRune(char) {
+		return 0, false
+	}
+	low, high := 0, len(c.groups)/12
+	for low < high {
+		middle := low + (high-low)/2
+		group := c.groups[middle*12:]
+		first, last := binary.BigEndian.Uint32(group), binary.BigEndian.Uint32(group[4:])
+		if uint32(char) < first {
+			high = middle
+		} else if uint32(char) > last {
+			low = middle + 1
+		} else {
+			glyph := uint64(binary.BigEndian.Uint32(group[8:])) + uint64(uint32(char)-first)
+			return uint16(glyph), glyph > 0 && glyph <= 65535
+		}
+	}
+	return 0, false
+}
+
+// UnitsPerEm 返回字体设计单位
+// 返回: uint16 每em单位数
+func (f *SFNT) UnitsPerEm() uint16 { return f.units }
+
+// NumGlyphs 返回字形总数
+// 返回: uint16 字形数
+func (f *SFNT) NumGlyphs() uint16 { return f.count }
+
+// CmapEntries 返回各编码记录的映射项总数，共享子表按记录分别计数
+// 返回: uint64 用于缓存预算的映射项数量
+func (f *SFNT) CmapEntries() uint64 {
+	var count uint64
+	for _, cmap := range f.cmaps {
+		count += uint64(len(cmap.mapping)) + cmap.entries
+	}
+	return count
+}
+
+// GlyphIndex 按编码表顺序查找字符，不替换缺失字形
+// 入参: char 字符
+// 返回: uint16 字形编号
+func (f *SFNT) GlyphIndex(char rune) uint16 {
+	for _, cmap := range f.cmaps {
+		if cmap.duplicate {
+			continue
+		}
+		if gid, ok := cmap.lookup(char); ok && gid != 0 {
+			return gid
+		}
+	}
+	return 0
+}
+
+// glyphCharacters 返回指向指定字形的全部字符，连续区间按需反查
+// 入参: gid 字形编号
+// 返回: []rune 排序后的字符
+func (f *SFNT) glyphCharacters(gid uint16) []rune {
+	f.reverseOnce.Do(func() {
+		f.reverse = make(map[uint16][]rune)
+		seen := make(map[rune]bool)
+		for _, cmap := range f.cmaps {
+			if cmap.duplicate {
+				continue
+			}
+			for char, glyph := range cmap.mapping {
+				if glyph != 0 && !seen[char] && f.GlyphIndex(char) == glyph {
+					f.reverse[glyph] = append(f.reverse[glyph], char)
+					seen[char] = true
+				}
+			}
+		}
+		for _, chars := range f.reverse {
+			slices.Sort(chars)
+		}
+	})
+	if gid == 0 {
+		return nil
+	}
+	chars := slices.Clone(f.reverse[gid])
+	for _, cmap := range f.cmaps {
+		if cmap.duplicate {
+			continue
+		}
+		for offset := 0; offset+12 <= len(cmap.groups); offset += 12 {
+			group := cmap.groups[offset:]
+			first, last, glyph := binary.BigEndian.Uint32(group), binary.BigEndian.Uint32(group[4:]), binary.BigEndian.Uint32(group[8:])
+			if first > last || uint32(gid) < glyph {
+				continue
+			}
+			char := uint64(first) + uint64(uint32(gid)-glyph)
+			if char <= uint64(last) && char <= utf8.MaxRune && utf8.ValidRune(rune(char)) && f.GlyphIndex(rune(char)) == gid {
+				chars = append(chars, rune(char))
+			}
+		}
+	}
+	slices.Sort(chars)
+	return slices.Compact(chars)
+}
+
+// GlyphAdvance 返回水平字宽
+// 入参: gid 字形编号
+// 返回: uint16 字宽
+func (f *SFNT) GlyphAdvance(gid uint16) uint16 {
+	if gid >= f.count {
+		return 0
+	}
+	return binary.BigEndian.Uint16(f.Tables["hmtx"][int(min(gid, f.horizontal-1))*4:])
+}
+
+// GlyphVerticalAdvance 返回纵向字距，无垂直度量时使用em高度
+// 入参: gid 字形编号
+// 返回: uint16 纵向字距
+func (f *SFNT) GlyphVerticalAdvance(gid uint16) uint16 {
+	if f.vertical == 0 {
+		return f.units
+	}
+	if gid >= f.count {
+		return 0
+	}
+	return binary.BigEndian.Uint16(f.Tables["vmtx"][int(min(gid, f.vertical-1))*4:])
+}
+
+// sideBearing 返回指定方向的字形边距
+// 入参: gid 字形编号, vertical 是否读取顶部边距
+// 返回: int16 边距
+func (f *SFNT) sideBearing(gid uint16, vertical bool) int16 {
+	data, count := f.Tables["hmtx"], f.horizontal
+	if vertical {
+		data, count = f.Tables["vmtx"], f.vertical
+	}
+	if count == 0 || gid >= f.count {
+		return 0
+	}
+	offset := int(gid)*4 + 2
+	if gid >= count {
+		offset = int(count)*4 + int(gid-count)*2
+	}
+	return int16(binary.BigEndian.Uint16(data[offset:]))
+}
+
+// VerticalMetrics 依据OS/2排版标志选择行度量，缺失时使用hhea
+// 返回: uint16 上升高度, uint16 下降高度, uint16 行间隙
+func (f *SFNT) VerticalMetrics() (uint16, uint16, uint16) {
+	hhea, os2 := f.Tables["hhea"], f.Tables["OS/2"]
+	a, d, gap := int(int16(binary.BigEndian.Uint16(hhea[4:]))), int(int16(binary.BigEndian.Uint16(hhea[6:]))), int(int16(binary.BigEndian.Uint16(hhea[8:])))
+	if len(os2) >= 78 {
+		if binary.BigEndian.Uint16(os2[62:])&0x80 != 0 {
+			ta, td := int(int16(binary.BigEndian.Uint16(os2[68:]))), int(int16(binary.BigEndian.Uint16(os2[70:])))
+			if ta > 0 && td < 0 {
+				a, d, gap = ta, td, int(int16(binary.BigEndian.Uint16(os2[72:])))
+			}
+		} else {
+			wa, wd := int(binary.BigEndian.Uint16(os2[74:])), int(binary.BigEndian.Uint16(os2[76:]))
+			if wa != 0 && wd != 0 {
+				gap, a, d = a-d+gap-wa-wd, wa, -wd
+			}
+		}
+	}
+	return uint16(max(0, a)), uint16(max(0, -d)), uint16(min(65535, max(0, gap)))
+}
+
+// Write 保留原始表数据并重新计算字体校验和
+// 返回: []byte 独立字体
+func (f *SFNT) Write() []byte { data, _ := SerializeOTF(f.Tables); return data }
+
+// glyphDependencies 批量收集复合字形依赖，校验引用、记录长度和嵌套深度
+// 入参: glyphs 字形编号
+// 返回: []uint16 依赖字形, error 字形错误
+func (f *SFNT) glyphDependencies(glyphs ...uint16) ([]uint16, error) {
+	heights, active := make(map[uint16]int), make(map[uint16]bool)
+	var result []uint16
+	var visit func(uint16) error
+	visit = func(id uint16) error {
+		if id >= f.count || active[id] || len(active) > 64 {
+			return fmt.Errorf("invalid composite glyph reference")
+		}
+		if height := heights[id]; height != 0 {
+			if len(active)+height > 65 {
+				return fmt.Errorf("invalid composite glyph reference")
+			}
+			return nil
+		}
+		heights[id], active[id] = 1, true
+		defer delete(active, id)
+		data, err := trueTypeGlyphData(f.Tables, id)
+		if err != nil {
+			return err
+		}
+		if len(data) == 0 {
+			return nil
+		}
+		if len(data) < 10 {
+			return fmt.Errorf("truncated glyph header")
+		}
+		if int16(binary.BigEndian.Uint16(data)) >= 0 {
+			return nil
+		}
+		for pos := 10; ; {
+			if len(data)-pos < 4 {
+				return fmt.Errorf("truncated composite glyph")
+			}
+			flags, child := binary.BigEndian.Uint16(data[pos:]), binary.BigEndian.Uint16(data[pos+2:])
+			pos += 6
+			if flags&1 != 0 {
+				pos += 2
+			}
+			switch flags & 0xc8 {
+			case 8:
+				pos += 2
+			case 0x40:
+				pos += 4
+			case 0x80:
+				pos += 8
+			case 0:
+			default:
+				return fmt.Errorf("invalid composite transform")
+			}
+			if pos > len(data) {
+				return fmt.Errorf("truncated composite transform")
+			}
+			if heights[child] == 0 {
+				result = append(result, child)
+			}
+			if err := visit(child); err != nil {
+				return err
+			}
+			heights[id] = max(heights[id], heights[child]+1)
+			if flags&0x20 == 0 {
+				break
+			}
+		}
+		return nil
+	}
+	for _, id := range glyphs {
+		if err := visit(id); err != nil {
+			return nil, err
+		}
+	}
+	return result, nil
+}

internal/base/font/subset.go

@@ -0,0 +1,460 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package font
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"maps"
+	"slices"
+
+	"github.com/go-text/typesetting/font/opentype/tables"
+)
+
+// Subsettable 判断默认资源后端能否无损裁剪该字体
+// 入参: sfnt 已解析字体
+// 返回: bool 是否支持裁剪
+func Subsettable(sfnt *SFNT) bool {
+	if fontEmbeddingFlags(sfnt)&0x0100 != 0 || slices.ContainsFunc([]string{"COLR", "CBDT", "sbix", "SVG "}, func(tag string) bool { return sfnt.Tables[tag] != nil }) {
+		return false
+	}
+	if sfnt.IsCFF {
+		if sfnt.Tables["fvar"] != nil {
+			return false
+		}
+		font, err := readType2Font(sfnt.Tables["CFF "])
+		if err == nil {
+			return len(font.chars) == int(sfnt.NumGlyphs())
+		}
+		cid, err := readCIDSubsetFont(sfnt.Tables["CFF "])
+		return err == nil && len(cid.fonts[0].chars) == int(sfnt.NumGlyphs())
+	}
+	return sfnt.IsTrueType && (sfnt.Tables["fvar"] == nil || variableSFNTSubsettable(sfnt))
+}
+
+// fontEmbeddingFlags 读取OpenType的嵌入标志，未提供OS/2表时返回零
+// 入参: sfnt 已解析字体
+// 返回: uint16 嵌入标志
+func fontEmbeddingFlags(sfnt *SFNT) uint16 {
+	if table := sfnt.Tables["OS/2"]; len(table) >= 10 {
+		return binary.BigEndian.Uint16(table[8:10])
+	}
+	return 0
+}
+
+// ValidateEmbedding 校验字体是否允许作为可编辑轮廓字体嵌入
+// 入参: data 独立OpenType字体
+// 返回: error 字体解析或嵌入限制
+func ValidateEmbedding(data []byte) error {
+	sfnt, err := ParseSFNT(data)
+	if err != nil {
+		return err
+	}
+	flags := fontEmbeddingFlags(sfnt)
+	if flags&0x0200 != 0 || flags&0x000e != 0 && flags&0x0008 == 0 {
+		return fmt.Errorf("font does not permit editable embedding")
+	}
+	return nil
+}
+
+// SFNTName 获取字体中的名称
+// 入参: sfnt 字体, names 名称类型，按顺序查找
+// 返回: string 字体名称
+func SFNTName(sfnt *SFNT, names ...uint16) string {
+	records, values := fontNameValues(sfnt.Tables["name"])
+	for _, name := range names {
+		for _, record := range records {
+			if record.Name != name {
+				continue
+			}
+			if value := values[[4]uint16{record.Platform, record.Encoding, record.Language, name}]; value != "" {
+				return value
+			}
+		}
+	}
+	return ""
+}
+
+// SubsetSFNT 按实际用字裁剪字体，保留字符映射、名称及度量
+// 入参: data 字体数据, glyphs 已排序的字形编号，包含0, mapped 是否保留显式字形编号
+// 返回: []byte 字体子集, error 错误信息
+func SubsetSFNT(data []byte, glyphs []uint16, mapped bool) ([]byte, error) {
+	data, err := DefaultCFF2Font(data)
+	if err != nil {
+		return nil, err
+	}
+	sfnt, err := ParseSFNT(data)
+	if err != nil {
+		return nil, err
+	}
+	if fontEmbeddingFlags(sfnt)&0x0100 != 0 {
+		return bytes.Clone(data), nil
+	}
+	if sfnt.IsCFF {
+		count, err := parseCFFAndCountGlyphs(sfnt.Tables["CFF "])
+		if err != nil {
+			return nil, err
+		}
+		if count != int(sfnt.NumGlyphs()) {
+			return nil, fmt.Errorf("CFF glyph count does not match maxp")
+		}
+		return subsetCFFFont(sfnt, glyphs, mapped)
+	}
+	if sfnt.Tables["fvar"] != nil {
+		return subsetVariableSFNTFont(sfnt, glyphs)
+	}
+	if mapped {
+		usage := newUsage()
+		for _, id := range glyphs {
+			usage.Glyphs[id] = true
+			for _, char := range sfnt.glyphCharacters(id) {
+				usage.Characters[char] = true
+			}
+		}
+		tables := make(map[string][]byte)
+		for _, tag := range []string{"cmap", "head", "hhea", "hmtx", "vhea", "vmtx", "maxp", "OS/2", "post", "name", "glyf", "loca", "cvt ", "fpgm", "prep", "gasp"} {
+			if table := sfnt.Tables[tag]; table != nil {
+				tables[tag] = table
+			}
+		}
+		fixed, err := SerializeOTF(tables)
+		if err != nil {
+			return nil, err
+		}
+		sfnt.Tables = tables
+		if subset := subsetSourceSFNT(sfnt, usage, len(fixed)); subset != nil {
+			return subset, nil
+		}
+		return fixed, nil
+	}
+	return subsetCompactSFNTFont(sfnt, glyphs)
+}
+
+// SubsetSourceSFNT 裁剪静态TrueType或CFF原有字体，保留字形编号、组合依赖、度量和提示指令
+// 字形替换结果一并保留，集合、可变、彩色和未知表保持原样
+// 入参: data 字体数据, usage 全包用字记录
+// 返回: []byte 更小的字体子集，无确定收益时为空
+func SubsetSourceSFNT(data []byte, usage *Usage) []byte {
+	if usage == nil || usage.Unsafe || len(usage.Characters)+len(usage.Glyphs) == 0 || bytes.HasPrefix(data, []byte("ttcf")) {
+		return nil
+	}
+	fontTables, err := FileTables(data, 0)
+	if err != nil {
+		return nil
+	}
+	for tag := range fontTables {
+		switch tag {
+		case "cmap", "head", "hhea", "hmtx", "maxp", "OS/2", "post", "name", "glyf", "loca", "CFF ", "cvt ", "fpgm", "prep", "gasp", "kern", "vhea", "vmtx", "VORG", "hdmx", "LTSH", "VDMX", "GDEF", "GPOS", "GSUB", "meta", "DSIG", "FFTM", "PCLT":
+		default:
+			return nil
+		}
+	}
+	sfnt, err := ParseSFNTTables(fontTables)
+	if err != nil {
+		return nil
+	}
+	return subsetSourceSFNT(sfnt, usage, len(data))
+}
+
+// subsetSourceSFNT 复用已校验的字体表裁剪字形，仅返回小于原编码的结果
+// 入参: sfnt 已解析字体, usage 用字记录, size 原编码长度
+// 返回: []byte 更小的字体子集，无确定收益时为空
+func subsetSourceSFNT(sfnt *SFNT, usage *Usage, size int) []byte {
+	if usage == nil || usage.Unsafe || len(usage.Characters)+len(usage.Glyphs) == 0 || !sfnt.IsTrueType && !sfnt.IsCFF || fontEmbeddingFlags(sfnt)&0x0100 != 0 {
+		return nil
+	}
+	var unicodeTables []sfntCmap
+	for _, record := range sfnt.cmaps {
+		if record.format == 14 {
+			continue
+		}
+		if record.platform == 0 || record.platform == 3 && (record.encoding == 1 || record.encoding == 10) {
+			unicodeTables = append(unicodeTables, record)
+		}
+	}
+	if len(unicodeTables) == 0 {
+		return nil
+	}
+	glyphs := maps.Clone(usage.Glyphs)
+	if glyphs == nil {
+		glyphs = make(map[uint16]bool)
+	}
+	glyphs[0] = true
+	mapping := make(map[rune]uint16, len(usage.Characters))
+	for char := range usage.Characters {
+		id := sfnt.GlyphIndex(char)
+		for _, cmap := range unicodeTables {
+			if alternate, ok := cmap.lookup(char); ok && alternate != id {
+				return nil
+			}
+		}
+		glyphs[id] = true
+		if id != 0 {
+			mapping[char] = id
+		}
+	}
+	variations, ok := subsetCmapVariations(sfnt.Tables["cmap"], usage.Characters, glyphs, sfnt.NumGlyphs())
+	if !ok || !retainSFNTSubstitutions(sfnt.Tables["GSUB"], glyphs, sfnt.NumGlyphs()) {
+		return nil
+	}
+	if sfnt.IsCFF {
+		count, err := parseCFFAndCountGlyphs(sfnt.Tables["CFF "])
+		if err != nil || count != int(sfnt.NumGlyphs()) {
+			return nil
+		}
+		cff, err := subsetCFFCharstrings(sfnt.Tables["CFF "], glyphs)
+		if err != nil {
+			return nil
+		}
+		tables := maps.Clone(sfnt.Tables)
+		tables["CFF "] = cff
+		tables["cmap"] = buildCmapWithVariations(sfnt.NumGlyphs(), mapping, variations)
+		delete(tables, "DSIG")
+		result, err := SerializeOTF(tables)
+		if err != nil || len(result) >= size {
+			return nil
+		}
+		return result
+	}
+	for id := 0; id < int(sfnt.NumGlyphs()); id++ {
+		if _, err := trueTypeGlyphData(sfnt.Tables, uint16(id)); err != nil {
+			return nil
+		}
+	}
+	dependencies, err := sfnt.glyphDependencies(slices.Collect(maps.Keys(glyphs))...)
+	if err != nil {
+		return nil
+	}
+	for _, dependency := range dependencies {
+		glyphs[dependency] = true
+	}
+	glyfSize := 0
+	for id, retained := range glyphs {
+		if retained {
+			data, _ := trueTypeGlyphData(sfnt.Tables, id)
+			glyfSize += len(data) + len(data)%2
+		}
+	}
+	locaFormat := binary.BigEndian.Uint16(sfnt.Tables["head"][50:])
+	glyf := make([]byte, 0, glyfSize)
+	loca := make([]byte, 0, (int(sfnt.NumGlyphs())+1)*(2+2*int(locaFormat)))
+	for id := 0; id <= int(sfnt.NumGlyphs()); id++ {
+		if locaFormat == 0 {
+			loca = binary.BigEndian.AppendUint16(loca, uint16(len(glyf)/2))
+		} else {
+			loca = binary.BigEndian.AppendUint32(loca, uint32(len(glyf)))
+		}
+		if id < int(sfnt.NumGlyphs()) && glyphs[uint16(id)] {
+			data, _ := trueTypeGlyphData(sfnt.Tables, uint16(id))
+			glyf = append(glyf, data...)
+			if len(glyf)%2 != 0 {
+				glyf = append(glyf, 0)
+			}
+		}
+	}
+	tables := maps.Clone(sfnt.Tables)
+	tables["glyf"], tables["loca"] = glyf, loca
+	tables["cmap"] = buildCmapWithVariations(sfnt.NumGlyphs(), mapping, variations)
+	tables["head"] = bytes.Clone(tables["head"])
+	clear(tables["head"][8:12])
+	delete(tables, "DSIG")
+	result, err := SerializeOTF(tables)
+	if err != nil || len(result) >= size {
+		return nil
+	}
+	return result
+}
+
+// retainSFNTSubstitutions 保留全部替换结果，使原字形替换表在裁剪后仍可使用
+// 入参: data 替换表, glyphs 待保留字形, count 字形总数
+// 返回: bool 替换表及结果编号是否有效
+func retainSFNTSubstitutions(data []byte, glyphs map[uint16]bool, count uint16) bool {
+	if len(data) == 0 {
+		return true
+	}
+	if len(data) < 10 || binary.BigEndian.Uint16(data) != 1 || binary.BigEndian.Uint16(data[2:]) > 1 {
+		return false
+	}
+	if binary.BigEndian.Uint16(data[2:]) == 1 && (len(data) < 14 || binary.BigEndian.Uint32(data[10:]) != 0) {
+		return false
+	}
+	layout, _, err := tables.ParseLayout(data)
+	if err != nil {
+		return false
+	}
+	for _, lookup := range layout.LookupList.Lookups {
+		subtables, err := lookup.AsGSUBLookups()
+		if err != nil {
+			return false
+		}
+		for _, subtable := range subtables {
+			if extension, ok := subtable.(tables.ExtensionSubs); ok {
+				if extension.ExtensionOffset < 8 || uint64(extension.ExtensionOffset) > uint64(len(extension.RawData)) {
+					return false
+				}
+				subtable, err = extension.Resolve()
+				if err != nil {
+					return false
+				}
+			}
+			if !retainSFNTSubstitution(subtable, glyphs, count) {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// retainSFNTSubstitution 收集替换子表的输出字形，上下文替换的结果由被引用的查找表提供
+// 入参: subtable 替换子表, glyphs 待保留字形, count 字形总数
+// 返回: bool 子表类型及输出字形是否有效
+func retainSFNTSubstitution(subtable tables.GSUBLookup, glyphs map[uint16]bool, count uint16) bool {
+	var outputs []tables.GlyphID
+	switch subtable := subtable.(type) {
+	case tables.SingleSubs:
+		switch data := subtable.Data.(type) {
+		case tables.SingleSubstData1:
+			for id := uint16(0); id < count; id++ {
+				if _, ok := data.Coverage.Index(tables.GlyphID(id)); ok {
+					outputs = append(outputs, tables.GlyphID(id+uint16(data.DeltaGlyphID)))
+				}
+			}
+		case tables.SingleSubstData2:
+			outputs = data.SubstituteGlyphIDs
+		default:
+			return false
+		}
+	case tables.MultipleSubs:
+		for _, sequence := range subtable.Sequences {
+			outputs = append(outputs, sequence.SubstituteGlyphIDs...)
+		}
+	case tables.AlternateSubs:
+		for _, set := range subtable.AlternateSets {
+			outputs = append(outputs, set.AlternateGlyphIDs...)
+		}
+	case tables.LigatureSubs:
+		for _, set := range subtable.LigatureSets {
+			for _, ligature := range set.Ligatures {
+				outputs = append(outputs, ligature.LigatureGlyph)
+			}
+		}
+	case tables.ReverseChainSingleSubs:
+		outputs = subtable.SubstituteGlyphIDs
+	case tables.ContextualSubs, tables.ChainedContextualSubs:
+	default:
+		return false
+	}
+	for _, id := range outputs {
+		if uint16(id) >= count {
+			return false
+		}
+		glyphs[uint16(id)] = true
+	}
+	return true
+}
+
+// subsetCompactSFNTFont 重排新建静态字体的字形，同步复合引用、字符映射和度量
+// 入参: sfnt 字体, glyphs 使用字形
+// 返回: []byte 紧凑字体子集, error 字形数据错误
+func subsetCompactSFNTFont(sfnt *SFNT, glyphs []uint16) ([]byte, error) {
+	ids := []uint16{0}
+	remap := map[uint16]uint16{0: 0}
+	for _, id := range glyphs {
+		if id >= sfnt.NumGlyphs() {
+			return nil, fmt.Errorf("font glyph index out of range")
+		}
+		if _, ok := remap[id]; !ok {
+			remap[id] = uint16(len(ids))
+			ids = append(ids, id)
+		}
+	}
+	dependencies, err := sfnt.glyphDependencies(ids...)
+	if err != nil {
+		return nil, err
+	}
+	for _, id := range dependencies {
+		if _, ok := remap[id]; !ok {
+			remap[id] = uint16(len(ids))
+			ids = append(ids, id)
+		}
+	}
+	table := make(map[string][]byte)
+	for _, tag := range []string{"head", "hhea", "maxp", "OS/2", "post", "name", "cvt ", "fpgm", "prep", "gasp", "vhea"} {
+		if data := sfnt.Tables[tag]; data != nil {
+			table[tag] = bytes.Clone(data)
+		}
+	}
+	var glyf, loca, hmtx, vmtx []byte
+	mapping := make(map[rune]uint16)
+	for _, id := range ids {
+		loca = binary.BigEndian.AppendUint32(loca, uint32(len(glyf)))
+		data, err := trueTypeGlyphData(sfnt.Tables, id)
+		if err != nil {
+			return nil, err
+		}
+		data = bytes.Clone(data)
+		if len(data) >= 10 && int16(binary.BigEndian.Uint16(data)) < 0 {
+			for pos := 10; ; {
+				flags := binary.BigEndian.Uint16(data[pos:])
+				child := binary.BigEndian.Uint16(data[pos+2:])
+				binary.BigEndian.PutUint16(data[pos+2:], remap[child])
+				pos += 6
+				if flags&1 != 0 {
+					pos += 2
+				}
+				switch flags & 0xc8 {
+				case 8:
+					pos += 2
+				case 0x40:
+					pos += 4
+				case 0x80:
+					pos += 8
+				}
+				if flags&0x20 == 0 {
+					break
+				}
+			}
+		}
+		glyf = append(glyf, data...)
+		for len(glyf)%4 != 0 {
+			glyf = append(glyf, 0)
+		}
+		hmtx = binary.BigEndian.AppendUint16(hmtx, sfnt.GlyphAdvance(id))
+		hmtx = binary.BigEndian.AppendUint16(hmtx, uint16(sfnt.sideBearing(id, false)))
+		if sfnt.vertical != 0 {
+			vmtx = binary.BigEndian.AppendUint16(vmtx, sfnt.GlyphVerticalAdvance(id))
+			vmtx = binary.BigEndian.AppendUint16(vmtx, uint16(sfnt.sideBearing(id, true)))
+		}
+		for _, char := range sfnt.glyphCharacters(id) {
+			mapping[char] = remap[id]
+		}
+	}
+	loca = binary.BigEndian.AppendUint32(loca, uint32(len(glyf)))
+	table["glyf"], table["loca"], table["hmtx"] = glyf, loca, hmtx
+	table["cmap"] = BuildCmapTable(uint16(len(ids)), mapping)
+	binary.BigEndian.PutUint16(table["head"][50:], 1)
+	binary.BigEndian.PutUint16(table["hhea"][34:], uint16(len(ids)))
+	binary.BigEndian.PutUint16(table["maxp"][4:], uint16(len(ids)))
+	if len(table["post"]) >= 32 {
+		table["post"] = table["post"][:32]
+		binary.BigEndian.PutUint32(table["post"], 0x30000)
+	}
+	if sfnt.vertical != 0 {
+		table["vmtx"] = vmtx
+		binary.BigEndian.PutUint16(table["vhea"][34:], uint16(len(ids)))
+	}
+	return SerializeOTF(table)
+}

internal/base/font/symbol.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package font
 
 import (
 	"context"
@@ -23,14 +23,14 @@ import (
 	"github.com/xiaoqidun/pdfgo"
 )
 
-// symbolFontProgram 为标准符号字体补齐Unicode映射，保留字形编号和轮廓
+// SymbolProgram 为标准符号字体补齐Unicode映射，保留字形编号和轮廓
 // 入参: ctx 取消上下文, data 独立字体数据, name 标准字体名，为空时从字体名称表识别
 // 返回: []byte 字体数据, map[string]uint16 标准字形编号，不适用时为空, error 映射或取消错误
-func symbolFontProgram(ctx context.Context, data []byte, name string) ([]byte, map[string]uint16, error) {
+func SymbolProgram(ctx context.Context, data []byte, name string) ([]byte, map[string]uint16, error) {
 	if err := ctx.Err(); err != nil {
 		return nil, nil, err
 	}
-	tables, err := fontFileTables(data, 0)
+	tables, err := FileTables(data, 0)
 	if err != nil {
 		return data, nil, nil
 	}
@@ -57,7 +57,7 @@ func symbolFontProgram(ctx context.Context, data []byte, name string) ([]byte, m
 	if err != nil {
 		return nil, nil, err
 	}
-	original := parseCmapMappings(tables["cmap"])
+	original := ParseCmapMappings(tables["cmap"])
 	mapping := make(map[rune]uint16)
 	names := make(map[string]uint16)
 	for _, glyph := range glyphs {
@@ -90,8 +90,8 @@ func symbolFontProgram(ctx context.Context, data []byte, name string) ([]byte, m
 	if !legacy || len(mapping) == 0 {
 		return data, names, nil
 	}
-	tables["cmap"] = buildCmapTable(0, mapping)
-	program, err := serializeOTF(tables)
+	tables["cmap"] = BuildCmapTable(0, mapping)
+	program, err := SerializeOTF(tables)
 	return program, names, err
 }
 
@@ -99,8 +99,8 @@ func symbolFontProgram(ctx context.Context, data []byte, name string) ([]byte, m
 // 入参: data 名称表数据
 // 返回: string 标准字体名，无法识别时为空
 func symbolFontName(data []byte) string {
-	for _, name := range fontNamesFromTable(data) {
-		switch fontNormalizeName(name) {
+	for _, name := range NamesFromTable(data) {
+		switch NormalizeName(name) {
 		case "symbol", "symbolmt", "symbolregular":
 			return "Symbol"
 		case "zapfdingbats", "zapfdingbatsregular", "itczapfdingbats":

internal/base/font/ttf.go

@@ -12,17 +12,53 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package font
 
 import (
 	"bytes"
 	"encoding/binary"
 )
 
+// NormalizeOS2 去除已知版本OS/2表的冗余零尾部，保留所有标准字段
+// 入参: data 原始表数据
+// 返回: []byte 规范化表数据，未知版本、截断或非零尾部保持原样
+func NormalizeOS2(data []byte) []byte {
+	if len(data) < 2 {
+		return data
+	}
+	var size int
+	switch binary.BigEndian.Uint16(data) {
+	case 0:
+		size = 78
+	case 1:
+		size = 86
+	case 2, 3, 4:
+		size = 96
+	case 5:
+		size = 100
+	default:
+		return data
+	}
+	if len(data) <= size {
+		return data
+	}
+	for _, value := range data[size:] {
+		if value != 0 {
+			return data
+		}
+	}
+	return data[:size]
+}
+
 // fixTrueType 尝试修复TrueType/OpenType字体数据
 // 入参: data 原始字体数据, fixCmap 是否修复cmap, fixName 是否修复name
 // 返回: bool 是否修复, []byte 修复后数据, map[rune]uint16 字符映射, bool 是否缺失cmap, error 错误信息
 func fixTrueType(data []byte, fixCmap, fixName bool) (bool, []byte, map[rune]uint16, bool, error) {
+	original := data
+	data, err := DefaultCFF2Font(data)
+	if err != nil {
+		return false, original, nil, false, err
+	}
 	if len(data) < 12 {
 		return false, data, nil, false, nil
 	}
@@ -30,7 +66,7 @@ func fixTrueType(data []byte, fixCmap, fixName bool) (bool, []byte, map[rune]uin
 	isCFFSfnt := sfntTag == "OTTO"
 	numTables := binary.BigEndian.Uint16(data[4:6])
 	existingTables := make(map[string][]byte)
-	malformedDirectory := false
+	malformedDirectory := !bytes.Equal(original, data)
 	pos := 12
 	for i := 0; i < int(numTables); i++ {
 		if len(data) < pos+16 {
@@ -53,7 +89,7 @@ func fixTrueType(data []byte, fixCmap, fixName bool) (bool, []byte, map[rune]uin
 	}
 	if existingTables["CFF "] != nil {
 		isCFFSfnt = true
-		sanitized, err := sanitizeCFF(existingTables["CFF "])
+		sanitized, err := SanitizeCFF(existingTables["CFF "])
 		if err != nil {
 			return false, data, nil, false, err
 		}
@@ -61,7 +97,7 @@ func fixTrueType(data []byte, fixCmap, fixName bool) (bool, []byte, map[rune]uin
 		if head := existingTables["head"]; len(head) >= 20 {
 			units = binary.BigEndian.Uint16(head[18:20])
 		}
-		normalized, err := normalizeCFFCharstringsAt(sanitized, units)
+		normalized, err := NormalizeCFFCharstringsAt(sanitized, units)
 		if err != nil {
 			return false, data, nil, false, err
 		}
@@ -70,7 +106,7 @@ func fixTrueType(data []byte, fixCmap, fixName bool) (bool, []byte, map[rune]uin
 			malformedDirectory = true
 		}
 	}
-	cmap, err := normalizeCmap(existingTables["cmap"])
+	cmap, err := NormalizeCmap(existingTables["cmap"])
 	if err != nil {
 		return false, data, nil, false, err
 	}
@@ -78,6 +114,10 @@ func fixTrueType(data []byte, fixCmap, fixName bool) (bool, []byte, map[rune]uin
 		existingTables["cmap"] = cmap
 		malformedDirectory = true
 	}
+	if os2 := NormalizeOS2(existingTables["OS/2"]); len(os2) != len(existingTables["OS/2"]) {
+		existingTables["OS/2"] = os2
+		malformedDirectory = true
+	}
 	missingHead := existingTables["head"] == nil
 	if !missingHead {
 		head := existingTables["head"]
@@ -188,12 +228,12 @@ func fixTrueType(data []byte, fixCmap, fixName bool) (bool, []byte, map[rune]uin
 		descender = int16(binary.BigEndian.Uint16(hhea[6:8]))
 	}
 	if missingOS2 {
-		newTables["OS/2"] = buildOS2TableWithMetrics(ascender, descender)
+		newTables["OS/2"] = BuildOS2TableWithMetrics(ascender, descender)
 	}
 	var mapping map[rune]uint16
 	if fixCmap {
 		if !missingCmap {
-			mapping = parseCmapMappings(newTables["cmap"])
+			mapping = ParseCmapMappings(newTables["cmap"])
 		}
 		if len(mapping) == 0 && isCFFSfnt {
 			mapping = getCmapFromCFF(newTables["CFF "], int(numGlyphs))
@@ -201,16 +241,16 @@ func fixTrueType(data []byte, fixCmap, fixName bool) (bool, []byte, map[rune]uin
 		if len(mapping) == 0 {
 			mapping = make(map[rune]uint16)
 		}
-		addPackedGlyphMapping(mapping, numGlyphs)
-		newTables["cmap"] = buildCmapTable(numGlyphs, mapping)
+		AddPackedGlyphMapping(mapping, numGlyphs)
+		newTables["cmap"] = BuildCmapTable(numGlyphs, mapping)
 	}
 	if missingName && fixName {
 		newTables["name"] = buildNameTable()
 	}
 	if missingPost {
-		newTables["post"] = buildPostTable()
+		newTables["post"] = BuildPostTable()
 	}
-	finalData, err := serializeOTF(newTables)
+	finalData, err := SerializeOTF(newTables)
 	if err != nil {
 		return false, data, nil, missingCmap, err
 	}

internal/base/font/type1.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package font
 
 import (
 	"bytes"
@@ -41,8 +41,8 @@ var type1StandardNames = func() [256]string {
 	return names
 }()
 
-// type1Program 保存解密后的Type1字形与子程序
-type type1Program struct {
+// Type1Program 保存解密后的Type1字形与子程序
+type Type1Program struct {
 	glyphs []type1Glyph
 	subrs  [][]byte
 	lenIV  int
@@ -63,7 +63,7 @@ type type1Scanner struct {
 
 // type1Outline 保存字形指令的操作数栈及轮廓位置
 type type1Outline struct {
-	program    *type1Program
+	program    *Type1Program
 	steps      *int
 	active     map[string]bool
 	args       []float64
@@ -84,24 +84,24 @@ type type1Outline struct {
 	path       bytes.Buffer
 }
 
-// parseType1Program 读取Type1字体的字形程序及子程序
+// ParseType1Program 读取Type1字体的字形程序及子程序
 // 入参: data PFA或PFB字体数据
-// 返回: type1Program 字形和子程序, error 错误信息
-func parseType1Program(data []byte) (type1Program, error) {
+// 返回: Type1Program 字形和子程序, error 错误信息
+func ParseType1Program(data []byte) (Type1Program, error) {
 	var err error
 	data, err = flattenType1(data)
 	if err != nil {
-		return type1Program{}, err
+		return Type1Program{}, err
 	}
 	matrix, start, err := readType1Header(data)
 	if err != nil {
-		return type1Program{}, err
+		return Type1Program{}, err
 	}
 	for start < len(data) && type1Space(data[start]) {
 		start++
 	}
 	if start == len(data) {
-		return type1Program{}, fmt.Errorf("empty Type1 eexec data")
+		return Type1Program{}, fmt.Errorf("empty Type1 eexec data")
 	}
 	encrypted := data[start:]
 	if type1HexEncoded(encrypted) {
@@ -121,15 +121,15 @@ func parseType1Program(data []byte) (type1Program, error) {
 		}
 		encrypted = make([]byte, hex.DecodedLen(len(digits)))
 		if _, err := hex.Decode(encrypted, digits); err != nil {
-			return type1Program{}, fmt.Errorf("invalid Type1 eexec encoding: %w", err)
+			return Type1Program{}, fmt.Errorf("invalid Type1 eexec encoding: %w", err)
 		}
 	}
 	if len(encrypted) < 4 {
-		return type1Program{}, fmt.Errorf("invalid Type1 eexec data")
+		return Type1Program{}, fmt.Errorf("invalid Type1 eexec data")
 	}
 	decrypted := type1Decrypt(encrypted, 55665)[4:]
 	scanner := type1Scanner{data: decrypted}
-	program := type1Program{lenIV: 4, matrix: matrix}
+	program := Type1Program{lenIV: 4, matrix: matrix}
 	section := ""
 	for {
 		token := scanner.next()
@@ -140,7 +140,7 @@ func parseType1Program(data []byte) (type1Program, error) {
 		case "/lenIV":
 			value, err := strconv.Atoi(scanner.next())
 			if err != nil || value < -1 {
-				return type1Program{}, fmt.Errorf("invalid Type1 lenIV")
+				return Type1Program{}, fmt.Errorf("invalid Type1 lenIV")
 			}
 			program.lenIV = value
 		case "/Subrs":
@@ -157,18 +157,18 @@ func parseType1Program(data []byte) (type1Program, error) {
 			}
 			index, err := strconv.Atoi(scanner.next())
 			if err != nil || index < 0 || index > len(decrypted) {
-				return type1Program{}, fmt.Errorf("invalid Type1 subroutine index")
+				return Type1Program{}, fmt.Errorf("invalid Type1 subroutine index")
 			}
 			length, err := strconv.Atoi(scanner.next())
 			if err != nil {
-				return type1Program{}, fmt.Errorf("invalid Type1 subroutine length")
+				return Type1Program{}, fmt.Errorf("invalid Type1 subroutine length")
 			}
 			if !type1BinaryStart(scanner.next()) {
-				return type1Program{}, fmt.Errorf("missing Type1 subroutine data")
+				return Type1Program{}, fmt.Errorf("missing Type1 subroutine data")
 			}
 			raw, err := scanner.binary(length)
 			if err != nil {
-				return type1Program{}, err
+				return Type1Program{}, err
 			}
 			for len(program.subrs) <= index {
 				program.subrs = append(program.subrs, nil)
@@ -185,33 +185,91 @@ func parseType1Program(data []byte) (type1Program, error) {
 				continue
 			}
 			if !type1BinaryStart(scanner.next()) {
-				return type1Program{}, fmt.Errorf("missing Type1 glyph data")
+				return Type1Program{}, fmt.Errorf("missing Type1 glyph data")
 			}
 			raw, err := scanner.binary(length)
 			if err != nil {
-				return type1Program{}, err
+				return Type1Program{}, err
 			}
 			program.glyphs = append(program.glyphs, type1Glyph{name: name, data: raw})
 		}
 	}
 	if len(program.glyphs) == 0 {
-		return type1Program{}, fmt.Errorf("Type1 font has no glyphs")
+		return Type1Program{}, fmt.Errorf("Type1 font has no glyphs")
 	}
 	for index := range program.subrs {
+		if program.subrs[index] == nil {
+			continue
+		}
 		program.subrs[index], err = type1CharString(program.subrs[index], program.lenIV)
 		if err != nil {
-			return type1Program{}, err
+			return Type1Program{}, err
 		}
 	}
 	for index := range program.glyphs {
 		program.glyphs[index].data, err = type1CharString(program.glyphs[index].data, program.lenIV)
 		if err != nil {
-			return type1Program{}, fmt.Errorf("Type1 glyph %s: %w", program.glyphs[index].name, err)
+			return Type1Program{}, fmt.Errorf("Type1 glyph %s: %w", program.glyphs[index].name, err)
 		}
 	}
 	return program, nil
 }
 
+// NormalizePDFType1 修复完整加密分段之后的PFB明文尾部，不补齐加密或字形数据
+// 入参: data 原始PFB程序
+// 返回: []byte 原程序或独立修复容器, bool 是否修复, error 容器或程序错误
+func NormalizePDFType1(data []byte) ([]byte, bool, error) {
+	if len(data) < 6 || data[0] != 0x80 {
+		return data, false, nil
+	}
+	binarySeen := false
+	for offset := 0; offset+2 <= len(data) && data[offset] == 0x80; {
+		kind := data[offset+1]
+		if kind == 3 {
+			return data, false, nil
+		}
+		if offset+6 > len(data) || kind != 1 && kind != 2 {
+			return data, false, fmt.Errorf("incomplete PFB segment header")
+		}
+		length := uint64(binary.LittleEndian.Uint32(data[offset+2:]))
+		remaining := len(data) - offset - 6
+		if binarySeen && kind == 1 && remaining == 0 {
+			result := append(bytes.Clone(data[:offset]), 0x80, 3)
+			if _, err := ParseType1Program(result); err != nil {
+				return nil, false, err
+			}
+			return result, true, nil
+		}
+		if length > uint64(remaining) {
+			return nil, false, fmt.Errorf("incomplete PFB encrypted or text segment")
+		}
+		if binarySeen && kind == 1 && length == 0 {
+			tail := data[offset+6:]
+			if len(tail) < 2 || !bytes.Equal(tail[len(tail)-2:], []byte{0x80, 3}) {
+				return data, false, fmt.Errorf("unbounded PFB text trailer")
+			}
+			text := bytes.TrimSpace(tail[:len(tail)-2])
+			if !bytes.HasSuffix(text, []byte("cleartomark")) {
+				return data, false, fmt.Errorf("PFB trailer lacks cleartomark")
+			}
+			for _, b := range bytes.TrimSuffix(text, []byte("cleartomark")) {
+				if b != '0' && !type1Space(b) {
+					return data, false, fmt.Errorf("unexpected PFB text trailer")
+				}
+			}
+			result := bytes.Clone(data)
+			binary.LittleEndian.PutUint32(result[offset+2:], uint32(len(tail)-2))
+			if _, err := ParseType1Program(result); err != nil {
+				return nil, false, err
+			}
+			return result, true, nil
+		}
+		binarySeen = binarySeen || kind == 2
+		offset += 6 + int(length)
+	}
+	return data, false, nil
+}
+
 // readType1Header 读取明文字体矩阵及加密数据起点
 // 入参: data Type1程序
 // 返回: []float64 字体矩阵, int 加密起点, error 头部错误
@@ -426,7 +484,7 @@ func type1BinaryStart(token string) bool {
 // outline 将Type1字形指令转换为保留三次曲线的Type2程序
 // 入参: glyph 字形数据
 // 返回: []byte Type2字形程序, error 错误信息
-func (p *type1Program) outline(glyph type1Glyph) ([]byte, error) {
+func (p *Type1Program) outline(glyph type1Glyph) ([]byte, error) {
 	state := type1Outline{program: p, active: map[string]bool{glyph.name: true}}
 	ended, err := state.run(glyph.data, 0)
 	if err != nil {
@@ -840,10 +898,10 @@ func encodeType2Number(target *bytes.Buffer, value float64) error {
 	return nil
 }
 
-// toCFF 将Type1字形转换为保持三次轮廓的CFF字体
+// ToCFF 将Type1字形转换为保持三次轮廓的CFF字体
 // 入参: name 字体名称
 // 返回: []byte CFF数据, error 错误信息
-func (p *type1Program) toCFF(name string) ([]byte, error) {
+func (p *Type1Program) ToCFF(name string) ([]byte, error) {
 	if len(p.glyphs) > math.MaxUint16 || name == "" {
 		return nil, fmt.Errorf("invalid Type1 font identity")
 	}
@@ -907,9 +965,9 @@ func (p *type1Program) toCFF(name string) ([]byte, error) {
 	return data, nil
 }
 
-// glyphIDs 返回Type1名称到转换后字形编号的对应关系
+// GlyphIDs 返回Type1名称到转换后字形编号的对应关系
 // 返回: map[string]uint16 字形编号
-func (p *type1Program) glyphIDs() map[string]uint16 {
+func (p *Type1Program) GlyphIDs() map[string]uint16 {
 	ids := map[string]uint16{".notdef": 0}
 	next := uint16(1)
 	for _, glyph := range p.glyphs {

internal/base/font/type2.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package font
 
 import (
 	"bytes"
@@ -30,6 +30,7 @@ type type2Font struct {
 	names        map[string]int
 	nominal, def float64
 	seed         uint64
+	cid          bool
 }
 
 // type2State 按Type2规范保存跨子程序共享的执行状态
@@ -54,6 +55,9 @@ type type2State struct {
 	output           *bytes.Buffer
 	seed             uint64
 	steps            *int
+	dependencies     map[uint16]bool
+	localUsage       []bool
+	globalUsage      []bool
 }
 
 // readType2Index 读取并校验CFF索引的全部偏移，不复制程序字节
@@ -335,13 +339,18 @@ func (s *type2State) run(data []byte, depth int) (bool, error) {
 			value := s.args[len(s.args)-1]
 			s.args = s.args[:len(s.args)-1]
 			subrs := s.font.locals
+			usage := s.localUsage
 			if op == 29 {
 				subrs = s.font.globals
+				usage = s.globalUsage
 			}
 			value += float64(cffSubrBias(len(subrs)))
 			if value < 0 || value >= float64(len(subrs)) || value != math.Trunc(value) {
 				return false, fmt.Errorf("invalid Type2 subroutine number")
 			}
+			if usage != nil {
+				usage[int(value)] = true
+			}
 			ended, err := s.run(subrs[int(value)], depth+1)
 			if ended || err != nil {
 				return ended, err
@@ -481,6 +490,9 @@ func (s *type2State) run(data []byte, depth int) (bool, error) {
 // 入参: code 标准字符码, x 横向偏移, y 纵向偏移
 // 返回: error 组件或指令错误
 func (s *type2State) appendComponent(code, x, y float64) error {
+	if s.font.cid {
+		return fmt.Errorf("CID CFF cannot use StandardEncoding components")
+	}
 	if code < 0 || code > 255 || code != math.Trunc(code) || type1StandardNames[int(code)] == "" {
 		return fmt.Errorf("invalid Type2 component code")
 	}
@@ -499,7 +511,10 @@ func (s *type2State) appendComponent(code, x, y float64) error {
 	if !ok {
 		return fmt.Errorf("missing Type2 component %s", name)
 	}
-	child := type2State{font: s.font, matrix: s.matrix, width: s.font.def, component: true, output: s.output, originX: x, originY: y, outX: s.outX, outY: s.outY, seed: s.font.seed + uint64(gid), steps: s.steps, stripHints: s.stripHints}
+	if s.dependencies != nil {
+		s.dependencies[uint16(gid)] = true
+	}
+	child := type2State{font: s.font, matrix: s.matrix, width: s.font.def, component: true, output: s.output, originX: x, originY: y, outX: s.outX, outY: s.outY, seed: s.font.seed + uint64(gid), steps: s.steps, stripHints: s.stripHints, dependencies: s.dependencies, localUsage: s.localUsage, globalUsage: s.globalUsage}
 	_, err := child.run(s.font.chars[gid], 0)
 	if err != nil {
 		return fmt.Errorf("invalid Type2 component %s: %w", name, err)

internal/base/font/type2_fd.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package font
 
 import (
 	"encoding/binary"

internal/base/font/type2_matrix.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package font
 
 import (
 	"fmt"

internal/base/font/type2_stack.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package font
 
 import (
 	"fmt"
@@ -27,6 +27,9 @@ func (s *type2State) calculate(op int) error {
 	count := 0
 	switch op {
 	case 1223:
+		if s.dependencies != nil {
+			return fmt.Errorf("random Type2 program cannot be subset safely")
+		}
 		s.seed = uint64(uint32(s.seed*1664525 + 1013904223))
 		return s.push(float64(s.seed+1) / 4294967296)
 	case 1205, 1209, 1214, 1218, 1221, 1226, 1227, 1229:

internal/base/font/usage.go

@@ -0,0 +1,28 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package font
+
+// Usage 指定子集需要保留的字符、字形及引用是否存在不确定性
+type Usage struct {
+	Characters map[rune]bool
+	Glyphs     map[uint16]bool
+	Unsafe     bool
+}
+
+// newUsage 创建具有可写字符和字形集合的子集输入
+// 返回: *Usage 用字信息
+func newUsage() *Usage {
+	return &Usage{Characters: make(map[rune]bool), Glyphs: make(map[uint16]bool)}
+}

internal/base/font/util.go

@@ -12,46 +12,42 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package font
 
 import (
 	"bytes"
 	"encoding/binary"
 	"fmt"
+	"math"
 	"sort"
 )
 
-// otfTableRecord OTF表记录结构
-// 字段: tag 标签, checksum 校验和, offset 偏移, length 长度, data 数据
-type otfTableRecord struct {
-	tag      string
-	checksum uint32
-	offset   int
-	length   int
-	data     []byte
+// finite 判断数值是否有限
+// 入参: value 数值
+// 返回: bool 是否有限
+func finite(value float64) bool {
+	return !math.IsNaN(value) && !math.IsInf(value, 0)
 }
 
-// extractCollectionFont 提取集合中的单个OpenType字体，保留表内容并重新计算校验和
+// ExtractCollectionFont 提取集合中的单个OpenType字体，保留表内容并重新计算校验和
 // 入参: data 集合数据, index 字体索引
 // 返回: []byte 单字体数据, error 错误信息
-func extractCollectionFont(data []byte, index int) ([]byte, error) {
-	tables, err := fontFileTables(data, index)
+func ExtractCollectionFont(data []byte, index int) ([]byte, error) {
+	tables, err := FileTables(data, index)
 	if err != nil {
 		return nil, err
 	}
 	if len(tables["head"]) < 12 {
 		return nil, fmt.Errorf("invalid head font table")
 	}
-	tables["head"] = bytes.Clone(tables["head"])
-	clear(tables["head"][8:12])
-	return serializeOTF(tables)
+	return SerializeOTF(tables)
 }
 
-// fontFileTables 读取单字体或集合指定项的表目录，不复制表数据
+// FileTables 读取单字体或集合指定项的表目录，不复制表数据
 // 入参: data 字体数据, index 字体索引
 // 返回: map[string][]byte 字体表, error 错误信息
-func fontFileTables(data []byte, index int) (map[string][]byte, error) {
-	count, err := fontFileCount(data)
+func FileTables(data []byte, index int) (map[string][]byte, error) {
+	count, err := FileCount(data)
 	if err != nil {
 		return nil, err
 	}
@@ -91,23 +87,127 @@ func fontFileTables(data []byte, index int) (map[string][]byte, error) {
 	return tables, nil
 }
 
+// NormalizePDFProgram 修复可确定的PDF内嵌SFNT封装，不补造TrueType轮廓或字形编号
+// 入参: data 原始字体程序
+// 返回: []byte 原程序或独立修复程序, bool 是否修复, error 无法确认的目录或度量错误
+func NormalizePDFProgram(data []byte) ([]byte, bool, error) {
+	if len(data) < 12 || string(data[:4]) != "OTTO" && string(data[:4]) != "\x00\x01\x00\x00" && string(data[:4]) != "true" {
+		return data, false, nil
+	}
+	count := int(binary.BigEndian.Uint16(data[4:6]))
+	if count == 0 || count > (len(data)-12)/16 {
+		return nil, false, fmt.Errorf("unrecoverable PDF font directory size")
+	}
+	first := len(data)
+	for n := 0; n < count; n++ {
+		record := data[12+n*16:]
+		start, size := uint64(binary.BigEndian.Uint32(record[8:])), uint64(binary.BigEndian.Uint32(record[12:]))
+		if size != 0 && start >= 12 && start+size <= uint64(len(data)) {
+			first = min(first, int(start))
+		}
+	}
+	changed := false
+	if first < 12+count*16 {
+		if (first-12)%16 != 0 {
+			return nil, false, fmt.Errorf("ambiguous PDF font directory overlap")
+		}
+		actual := (first - 12) / 16
+		for n := 0; n < count; n++ {
+			record := data[12+n*16:]
+			printable := true
+			for _, b := range record[:4] {
+				printable = printable && b >= 32 && b <= 126
+			}
+			if printable != (n < actual) {
+				return nil, false, fmt.Errorf("ambiguous PDF font table count")
+			}
+			if n < actual {
+				start, size := uint64(binary.BigEndian.Uint32(record[8:])), uint64(binary.BigEndian.Uint32(record[12:]))
+				if size != 0 && (start < uint64(first) || start+size > uint64(len(data))) {
+					return nil, false, fmt.Errorf("incomplete PDF font table")
+				}
+			}
+		}
+		data = bytes.Clone(data)
+		binary.BigEndian.PutUint16(data[4:6], uint16(actual))
+		changed = true
+	}
+	tables, err := FileTables(data, 0)
+	if err != nil {
+		return nil, false, err
+	}
+	if head := tables["head"]; len(head) > 54 && len(head) <= 57 {
+		tables["head"] = head[:54]
+		changed = true
+	}
+	if hhea := tables["hhea"]; len(hhea) > 36 && len(hhea) <= 39 && binary.BigEndian.Uint32(hhea) == 0x00010000 {
+		tables["hhea"] = hhea[:36]
+		changed = true
+	}
+	if maxp := tables["maxp"]; tables["glyf"] != nil && len(maxp) > 32 && len(maxp) <= 35 && binary.BigEndian.Uint32(maxp) == 0x00010000 {
+		tables["maxp"] = maxp[:32]
+		changed = true
+	}
+	if post := tables["post"]; len(post) > 32 && binary.BigEndian.Uint32(post) == 0x00030000 {
+		tables["post"] = post[:32]
+		changed = true
+	}
+	if cvt := tables["cvt "]; len(cvt)%2 != 0 && cvt[len(cvt)-1] == 0 {
+		tables["cvt "] = cvt[:len(cvt)-1]
+		changed = true
+	}
+	if len(tables["CFF "]) != 0 && len(tables["head"]) == 0 && len(tables["maxp"]) == 0 && len(tables["hhea"]) == 0 && len(tables["hmtx"]) == 0 {
+		program, _, err := WrapCFFToOTF(tables["CFF "])
+		return program, true, err
+	}
+	if maxp := tables["maxp"]; len(tables["CFF "]) != 0 && tables["glyf"] == nil && len(maxp) >= 6 && (binary.BigEndian.Uint32(maxp) == 0x00010000 || binary.BigEndian.Uint32(maxp) == 0x00005000 && len(maxp) != 6) {
+		count, err := parseCFFAndCountGlyphs(tables["CFF "])
+		if err != nil {
+			return nil, false, err
+		}
+		if count != int(binary.BigEndian.Uint16(maxp[4:6])) {
+			program, _, err := WrapCFFToOTF(tables["CFF "])
+			if err != nil {
+				return nil, false, err
+			}
+			rebuilt, err := FileTables(program, 0)
+			if err != nil {
+				return nil, false, err
+			}
+			if len(tables["head"]) < 20 || !bytes.Equal(tables["head"][18:20], rebuilt["head"][18:20]) {
+				return nil, false, fmt.Errorf("CFF and SFNT design units differ")
+			}
+			return program, true, nil
+		}
+		tables["maxp"] = buildCFFMaxpTable(uint16(count))
+		changed = true
+	}
+	if !changed {
+		return data, false, nil
+	}
+	program, err := SerializeOTF(tables)
+	return program, true, err
+}
+
 // calcTableChecksum 计算字体表校验和
 // 入参: data 表数据
 // 返回: uint32 校验和
 func calcTableChecksum(data []byte) uint32 {
-	var sum uint32
-	length := len(data)
-	for i := 0; i < length; i += 4 {
-		if i+4 <= length {
-			sum += binary.BigEndian.Uint32(data[i : i+4])
-		} else {
-			var val uint32
-			rem := data[i:]
-			for j, b := range rem {
-				val |= uint32(b) << (24 - 8*j)
-			}
-			sum += val
-		}
+	var a, b, c, d uint32
+	for len(data) >= 16 {
+		a += binary.BigEndian.Uint32(data[:4])
+		b += binary.BigEndian.Uint32(data[4:8])
+		c += binary.BigEndian.Uint32(data[8:12])
+		d += binary.BigEndian.Uint32(data[12:16])
+		data = data[16:]
+	}
+	sum := a + b + c + d
+	for len(data) >= 4 {
+		sum += binary.BigEndian.Uint32(data[:4])
+		data = data[4:]
+	}
+	for i, value := range data {
+		sum += uint32(value) << (24 - 8*i)
 	}
 	return sum
 }
@@ -190,13 +290,13 @@ func buildTrueTypeMaxpTable(numGlyphs uint16) []byte {
 // buildOS2Table 构建OS/2表 (使用默认Metrics)
 // 返回: []byte OS/2表数据
 func buildOS2Table() []byte {
-	return buildOS2TableWithMetrics(800, -200)
+	return BuildOS2TableWithMetrics(800, -200)
 }
 
-// buildOS2TableWithMetrics 构建OS/2表
+// BuildOS2TableWithMetrics 构建OS/2表
 // 入参: ascender 上升部, descender 下降部
 // 返回: []byte OS/2表数据
-func buildOS2TableWithMetrics(ascender, descender int16) []byte {
+func BuildOS2TableWithMetrics(ascender, descender int16) []byte {
 	os2 := new(bytes.Buffer)
 	binary.Write(os2, binary.BigEndian, uint16(3))
 	binary.Write(os2, binary.BigEndian, int16(500))
@@ -252,9 +352,9 @@ func buildNameTable() []byte {
 	return buf.Bytes()
 }
 
-// buildPostTable 构建post表 (版本3.0, 无字形名称)
+// BuildPostTable 构建post表 (版本3.0, 无字形名称)
 // 返回: []byte post表数据
-func buildPostTable() []byte {
+func BuildPostTable() []byte {
 	buf := new(bytes.Buffer)
 	binary.Write(buf, binary.BigEndian, uint32(0x00030000))
 	binary.Write(buf, binary.BigEndian, uint32(0))
@@ -280,68 +380,70 @@ func buildHmtxTable(widths []uint16) []byte {
 	return buf.Bytes()
 }
 
-// serializeOTF 序列化OpenType字体结构
+// SerializeOTF 序列化OpenType字体结构，一次分配输出，不修改输入表数据
+// 复用各表校验和计算整份字体的调整值，不重复扫描表数据
 // 入参: tables 表数据映射
 // 返回: []byte 完整字体数据, error 错误信息
-func serializeOTF(tables map[string][]byte) ([]byte, error) {
-	numTables := uint16(len(tables))
+func SerializeOTF(tables map[string][]byte) ([]byte, error) {
+	if len(tables) > math.MaxUint16/16 {
+		return nil, fmt.Errorf("too many font tables")
+	}
+	headerSize := 12 + 16*len(tables)
+	size := uint64(headerSize)
+	tags := make([]string, 0, len(tables))
+	for tag, data := range tables {
+		if len(tag) != 4 {
+			return nil, fmt.Errorf("invalid font table tag %q", tag)
+		}
+		if tag == "head" && len(data) < 12 {
+			return nil, fmt.Errorf("invalid head font table")
+		}
+		size += (uint64(len(data)) + 3) &^ 3
+		if size > math.MaxUint32 || size > uint64(math.MaxInt) {
+			return nil, fmt.Errorf("font table data too large")
+		}
+		tags = append(tags, tag)
+	}
+	sort.Strings(tags)
+	data := make([]byte, int(size))
+	numTables := len(tables)
 	entrySelector := 0
-	for 1<<(entrySelector+1) <= int(numTables) {
+	for 1<<(entrySelector+1) <= numTables {
 		entrySelector++
 	}
 	searchRange := 1 << (entrySelector + 4)
-	rangeShift := int(numTables)*16 - searchRange
-	buf := new(bytes.Buffer)
-	if _, ok := tables["CFF "]; ok {
-		buf.WriteString("OTTO")
+	rangeShift := numTables*16 - searchRange
+	if tables["CFF "] != nil || tables["CFF2"] != nil {
+		copy(data, "OTTO")
 	} else {
-		binary.Write(buf, binary.BigEndian, uint32(0x00010000))
+		binary.BigEndian.PutUint32(data, 0x00010000)
 	}
-	binary.Write(buf, binary.BigEndian, numTables)
-	binary.Write(buf, binary.BigEndian, uint16(searchRange))
-	binary.Write(buf, binary.BigEndian, uint16(entrySelector))
-	binary.Write(buf, binary.BigEndian, uint16(rangeShift))
-	var tags []string
-	for t := range tables {
-		tags = append(tags, t)
-	}
-	sort.Strings(tags)
-	headerSize := 12 + 16*int(numTables)
-	offset := headerSize
-	var records []otfTableRecord
-	for _, tag := range tags {
-		data := tables[tag]
-		pad := (4 - (len(data) % 4)) % 4
-		padded := make([]byte, len(data)+pad)
-		copy(padded, data)
-		if tag == "head" && len(data) >= 12 {
+	binary.BigEndian.PutUint16(data[4:], uint16(numTables))
+	binary.BigEndian.PutUint16(data[6:], uint16(searchRange))
+	binary.BigEndian.PutUint16(data[8:], uint16(entrySelector))
+	binary.BigEndian.PutUint16(data[10:], uint16(rangeShift))
+	offset, adjustment := headerSize, 0
+	var checksum uint32
+	for i, tag := range tags {
+		table := tables[tag]
+		length := (len(table) + 3) &^ 3
+		padded := data[offset : offset+length]
+		copy(padded, table)
+		if tag == "head" {
 			clear(padded[8:12])
+			adjustment = offset + 8
 		}
-		cs := calcTableChecksum(padded)
-		records = append(records, otfTableRecord{tag, cs, offset, len(data), padded})
-		offset += len(padded)
+		record := data[12+i*16 : 28+i*16]
+		copy(record, tag)
+		tableChecksum := calcTableChecksum(padded)
+		checksum += tableChecksum
+		binary.BigEndian.PutUint32(record[4:], tableChecksum)
+		binary.BigEndian.PutUint32(record[8:], uint32(offset))
+		binary.BigEndian.PutUint32(record[12:], uint32(len(table)))
+		offset += length
 	}
-	for _, r := range records {
-		buf.WriteString(r.tag)
-		binary.Write(buf, binary.BigEndian, r.checksum)
-		binary.Write(buf, binary.BigEndian, uint32(r.offset))
-		binary.Write(buf, binary.BigEndian, uint32(r.length))
+	if adjustment != 0 {
+		binary.BigEndian.PutUint32(data[adjustment:], 0xB1B0AFBA-checksum-calcTableChecksum(data[:headerSize]))
 	}
-	for _, r := range records {
-		buf.Write(r.data)
-	}
-	fullData := buf.Bytes()
-	for _, r := range records {
-		if r.tag == "head" {
-			adjOffset := r.offset + 8
-			if adjOffset+4 <= len(fullData) {
-				binary.BigEndian.PutUint32(fullData[adjOffset:], 0)
-				cs := calcTableChecksum(fullData)
-				checksumAdj := 0xB1B0AFBA - cs
-				binary.BigEndian.PutUint32(fullData[adjOffset:], checksumAdj)
-			}
-			break
-		}
-	}
-	return fullData, nil
+	return data, nil
 }

internal/base/font/variable.go

@@ -0,0 +1,146 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package font
+
+import (
+	"encoding/binary"
+	"fmt"
+	"maps"
+	"slices"
+)
+
+// variableSFNTSubsettable 核对TrueType可变轴与字形变化表的基本结构
+// 入参: sfnt 已解析字体
+// 返回: bool 是否具备可裁剪的变化数据
+func variableSFNTSubsettable(sfnt *SFNT) bool {
+	fvar, gvar := sfnt.Tables["fvar"], sfnt.Tables["gvar"]
+	if len(fvar) < 16 || len(gvar) < 20 || binary.BigEndian.Uint32(fvar) != 0x10000 || binary.BigEndian.Uint32(gvar) != 0x10000 {
+		return false
+	}
+	axes := int(binary.BigEndian.Uint16(fvar[8:]))
+	offset, size := int(binary.BigEndian.Uint16(fvar[4:])), int(binary.BigEndian.Uint16(fvar[10:]))
+	return axes > 0 && size >= 20 && offset >= 16 && offset <= len(fvar) && axes <= (len(fvar)-offset)/size &&
+		int(binary.BigEndian.Uint16(gvar[4:])) == axes && binary.BigEndian.Uint16(gvar[12:]) == sfnt.NumGlyphs()
+}
+
+// subsetVariableSFNTFont 保留字形编号及可变轴，仅裁剪未使用的轮廓和字形变化数据
+// 入参: sfnt 已解析字体, glyphs 使用的字形
+// 返回: []byte 字体子集, error 字形或变化表错误
+func subsetVariableSFNTFont(sfnt *SFNT, glyphs []uint16) ([]byte, error) {
+	if !variableSFNTSubsettable(sfnt) {
+		return nil, fmt.Errorf("invalid TrueType variation tables")
+	}
+	usage := newUsage()
+	usage.Glyphs[0] = true
+	for _, gid := range glyphs {
+		if gid >= sfnt.NumGlyphs() {
+			return nil, fmt.Errorf("variable font glyph index out of range")
+		}
+		usage.Glyphs[gid] = true
+		for _, char := range sfnt.glyphCharacters(gid) {
+			usage.Characters[char] = true
+		}
+	}
+	dependencies, err := sfnt.glyphDependencies(slices.Collect(maps.Keys(usage.Glyphs))...)
+	if err != nil {
+		return nil, err
+	}
+	for _, dependency := range dependencies {
+		usage.Glyphs[dependency] = true
+	}
+	mapping := make(map[rune]uint16, len(usage.Characters))
+	for char := range usage.Characters {
+		mapping[char] = sfnt.GlyphIndex(char)
+	}
+	table := make(map[string][]byte)
+	for _, tag := range []string{"head", "hhea", "hmtx", "maxp", "OS/2", "post", "name", "glyf", "loca", "cvt ", "fpgm", "prep", "gasp", "vhea", "vmtx"} {
+		if data := sfnt.Tables[tag]; data != nil {
+			table[tag] = data
+		}
+	}
+	table["cmap"] = BuildCmapTable(sfnt.NumGlyphs(), mapping)
+	static, err := SerializeOTF(table)
+	if err != nil {
+		return nil, err
+	}
+	if subset := SubsetSourceSFNT(static, usage); subset != nil {
+		table, err = FileTables(subset, 0)
+		if err != nil {
+			return nil, err
+		}
+	}
+	table["gvar"], err = subsetGlyphVariations(sfnt.Tables["gvar"], usage.Glyphs)
+	if err != nil {
+		return nil, err
+	}
+	for _, tag := range []string{"fvar", "avar", "cvar", "HVAR", "VVAR", "MVAR", "STAT"} {
+		if data := sfnt.Tables[tag]; data != nil {
+			table[tag] = data
+		}
+	}
+	return SerializeOTF(table)
+}
+
+// subsetGlyphVariations 按原字形编号重建gvar偏移表，保留共享元组及使用字形的完整变化数据
+// 入参: data gvar表, glyphs 保留字形集合
+// 返回: []byte 裁剪后的gvar表, error 表结构错误
+func subsetGlyphVariations(data []byte, glyphs map[uint16]bool) ([]byte, error) {
+	if len(data) < 20 || binary.BigEndian.Uint32(data) != 0x10000 {
+		return nil, fmt.Errorf("invalid gvar header")
+	}
+	axes := uint64(binary.BigEndian.Uint16(data[4:]))
+	tuples := uint64(binary.BigEndian.Uint16(data[6:]))
+	shared := uint64(binary.BigEndian.Uint32(data[8:]))
+	count := int(binary.BigEndian.Uint16(data[12:]))
+	flags := binary.BigEndian.Uint16(data[14:])
+	start := uint64(binary.BigEndian.Uint32(data[16:]))
+	width := 2
+	if flags&1 != 0 {
+		width = 4
+	}
+	sharedSize := axes * tuples * 2
+	headerEnd := uint64(20 + (count+1)*width)
+	if flags > 1 || headerEnd > uint64(len(data)) || start < headerEnd || start > uint64(len(data)) || shared > uint64(len(data)) || sharedSize > uint64(len(data))-shared || sharedSize != 0 && shared < headerEnd {
+		return nil, fmt.Errorf("invalid gvar offsets")
+	}
+	readOffset := func(index int) uint64 {
+		if width == 2 {
+			return uint64(binary.BigEndian.Uint16(data[20+index*2:])) * 2
+		}
+		return uint64(binary.BigEndian.Uint32(data[20+index*4:]))
+	}
+	output := make([]byte, 20+(count+1)*4)
+	copy(output, data[:20])
+	binary.BigEndian.PutUint16(output[14:], 1)
+	binary.BigEndian.PutUint32(output[8:], uint32(len(output)))
+	output = append(output, data[shared:shared+sharedSize]...)
+	base := len(output)
+	binary.BigEndian.PutUint32(output[16:], uint32(base))
+	for gid := range count {
+		first, last := readOffset(gid), readOffset(gid+1)
+		if last < first || last > uint64(len(data))-start {
+			return nil, fmt.Errorf("invalid gvar glyph offsets")
+		}
+		if last > first && sharedSize != 0 && start+first < shared+sharedSize && shared < start+last {
+			return nil, fmt.Errorf("overlapping gvar glyph and shared tuple data")
+		}
+		binary.BigEndian.PutUint32(output[20+gid*4:], uint32(len(output)-base))
+		if glyphs[uint16(gid)] {
+			output = append(output, data[start+first:start+last]...)
+		}
+	}
+	binary.BigEndian.PutUint32(output[20+count*4:], uint32(len(output)-base))
+	return output, nil
+}

internal/base/font/woff.go

@@ -0,0 +1,248 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package font
+
+import (
+	"bytes"
+	"compress/zlib"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"sort"
+
+	"github.com/andybalholm/brotli"
+)
+
+// fontContainerLimit 限制压缩字体展开后的表数据总量
+const fontContainerLimit = 256 << 20
+
+// woff2Tags 保存WOFF2表目录的标准标签顺序
+var woff2Tags = [...]string{
+	"cmap", "head", "hhea", "hmtx", "maxp", "name", "OS/2", "post",
+	"cvt ", "fpgm", "glyf", "loca", "prep", "CFF ", "VORG", "EBDT",
+	"EBLC", "gasp", "hdmx", "kern", "LTSH", "PCLT", "VDMX", "vhea",
+	"vmtx", "BASE", "GDEF", "GPOS", "GSUB", "EBSC", "JSTF", "MATH",
+	"CBDT", "CBLC", "COLR", "CPAL", "SVG ", "sbix", "acnt", "avar",
+	"bdat", "bloc", "bsln", "cvar", "fdsc", "feat", "fmtx", "fvar",
+	"gvar", "hsty", "just", "lcar", "mort", "morx", "opbd", "prop",
+	"trak", "Zapf", "Silf", "Glat", "Gloc", "Feat", "Sill",
+}
+
+// DecodeWOFF2 展开未变换的WOFF2表，字体集合及字形变换交由绘图适配器处理
+// 入参: data WOFF2文件
+// 返回: []byte OpenType数据, bool 是否已处理, error 封装错误
+func DecodeWOFF2(data []byte) ([]byte, bool, error) {
+	if len(data) < 48 || string(data[:4]) != "wOF2" || uint64(binary.BigEndian.Uint32(data[8:])) != uint64(len(data)) {
+		return nil, true, fmt.Errorf("invalid WOFF2 header")
+	}
+	if string(data[4:8]) == "ttcf" {
+		return nil, false, nil
+	}
+	count := int(binary.BigEndian.Uint16(data[12:]))
+	if count == 0 || count > (len(data)-48)/2 {
+		return nil, true, fmt.Errorf("invalid WOFF2 table count")
+	}
+	tags := make([]string, 0, count)
+	sizes := make([]uint32, 0, count)
+	table := make(map[string][]byte, count)
+	pos, total, transformed := 48, uint64(0), false
+	for range count {
+		if pos >= len(data) {
+			return nil, true, fmt.Errorf("truncated WOFF2 directory")
+		}
+		flags := data[pos]
+		pos++
+		var tag string
+		if index := flags & 63; index == 63 {
+			if len(data)-pos < 4 {
+				return nil, true, fmt.Errorf("truncated WOFF2 tag")
+			}
+			tag = string(data[pos : pos+4])
+			pos += 4
+		} else {
+			tag = woff2Tags[index]
+		}
+		if _, exists := table[tag]; exists {
+			return nil, true, fmt.Errorf("duplicate WOFF2 table %q", tag)
+		}
+		table[tag] = nil
+		size, err := readWOFF2Base128(data, &pos)
+		if err != nil {
+			return nil, true, err
+		}
+		version := flags >> 6
+		changed := version != 0
+		if tag == "glyf" || tag == "loca" {
+			if version != 0 && version != 3 {
+				return nil, true, fmt.Errorf("invalid WOFF2 glyph transform")
+			}
+			changed = version == 0
+		} else if version != 0 && (tag != "hmtx" || version != 1) {
+			return nil, true, fmt.Errorf("invalid WOFF2 table transform %q", tag)
+		}
+		if changed {
+			transformed = true
+			size, err = readWOFF2Base128(data, &pos)
+			if err != nil {
+				return nil, true, err
+			}
+			if tag == "loca" && size != 0 {
+				return nil, true, fmt.Errorf("invalid WOFF2 loca length")
+			}
+		}
+		total += uint64(size)
+		if total+uint64(12+19*count) > fontContainerLimit {
+			return nil, true, fmt.Errorf("WOFF2 font exceeds size limit")
+		}
+		tags = append(tags, tag)
+		sizes = append(sizes, size)
+	}
+	end := uint64(pos) + uint64(binary.BigEndian.Uint32(data[20:]))
+	if end > uint64(len(data)) {
+		return nil, true, fmt.Errorf("invalid WOFF2 compressed length")
+	}
+	if err := validateWOFFBlocks(data, end, 28); err != nil {
+		return nil, true, err
+	}
+	if transformed {
+		return nil, false, nil
+	}
+	reader := brotli.NewReader(bytes.NewReader(data[pos:end]))
+	body, err := io.ReadAll(io.LimitReader(reader, int64(total)+1))
+	if err != nil {
+		return nil, true, fmt.Errorf("decode WOFF2 data: %w", err)
+	}
+	if uint64(len(body)) != total {
+		return nil, true, fmt.Errorf("invalid WOFF2 expanded length")
+	}
+	for i, tag := range tags {
+		size := int(sizes[i])
+		table[tag], body = body[:size], body[size:]
+	}
+	decoded, err := SerializeOTF(table)
+	return decoded, true, err
+}
+
+// readWOFF2Base128 读取WOFF2无符号变长整数，拒绝溢出和前导零
+// 入参: data 编码数据, pos 当前读取位置
+// 返回: uint32 整数值, error 编码错误
+func readWOFF2Base128(data []byte, pos *int) (uint32, error) {
+	var value uint32
+	for i := range 5 {
+		if *pos >= len(data) {
+			return 0, fmt.Errorf("truncated WOFF2 integer")
+		}
+		b := data[*pos]
+		*pos++
+		if i == 0 && b == 0x80 || value > 0x1ffffff {
+			return 0, fmt.Errorf("invalid WOFF2 integer")
+		}
+		value = value<<7 | uint32(b&127)
+		if b&128 == 0 {
+			return value, nil
+		}
+	}
+	return 0, fmt.Errorf("invalid WOFF2 integer")
+}
+
+// DecodeWOFF 展开WOFF表数据，不解析或更改字体轮廓
+// 入参: data WOFF文件
+// 返回: []byte OpenType数据, error 封装错误
+func DecodeWOFF(data []byte) ([]byte, error) {
+	if len(data) < 44 || uint64(binary.BigEndian.Uint32(data[8:])) != uint64(len(data)) || binary.BigEndian.Uint16(data[14:]) != 0 {
+		return nil, fmt.Errorf("invalid WOFF header")
+	}
+	count := int(binary.BigEndian.Uint16(data[12:]))
+	if count == 0 || count > (len(data)-44)/20 {
+		return nil, fmt.Errorf("invalid WOFF table count")
+	}
+	table := make(map[string][]byte, count)
+	ranges := make([][2]uint64, 0, count)
+	total := uint64(12 + 16*count)
+	for i := range count {
+		record := data[44+i*20:]
+		tag := string(record[:4])
+		offset, packed, size := uint64(binary.BigEndian.Uint32(record[4:])), uint64(binary.BigEndian.Uint32(record[8:])), uint64(binary.BigEndian.Uint32(record[12:]))
+		total += (size + 3) &^ 3
+		if _, exists := table[tag]; exists || offset < uint64(44+20*count) || offset%4 != 0 || packed > size || offset+packed > uint64(len(data)) || total > fontContainerLimit {
+			return nil, fmt.Errorf("invalid WOFF table %q", tag)
+		}
+		body := data[offset : offset+packed]
+		if packed < size {
+			reader, err := zlib.NewReader(bytes.NewReader(body))
+			if err != nil {
+				return nil, err
+			}
+			body, err = io.ReadAll(io.LimitReader(reader, int64(size)+1))
+			reader.Close()
+			if err != nil {
+				return nil, err
+			}
+			if uint64(len(body)) != size {
+				return nil, fmt.Errorf("invalid WOFF expanded length")
+			}
+		}
+		table[tag] = body
+		ranges = append(ranges, [2]uint64{offset, offset + packed})
+	}
+	if total != uint64(binary.BigEndian.Uint32(data[16:])) {
+		return nil, fmt.Errorf("invalid WOFF SFNT size")
+	}
+	sort.Slice(ranges, func(i, j int) bool { return ranges[i][0] < ranges[j][0] })
+	end := uint64(44 + 20*count)
+	for _, interval := range ranges {
+		if interval[0] != (end+3)&^3 {
+			return nil, fmt.Errorf("invalid WOFF table ranges")
+		}
+		end = interval[1]
+	}
+	if err := validateWOFFBlocks(data, end, 24); err != nil {
+		return nil, err
+	}
+	return SerializeOTF(table)
+}
+
+// validateWOFFBlocks 校验附加数据块的边界及对齐，字体元数据不写入输出
+// 入参: data 字体文件, end 字体数据结束位置, fields 元数据偏移字段位置
+// 返回: error 附加块错误
+func validateWOFFBlocks(data []byte, end uint64, fields int) error {
+	for _, pos := range []int{fields, fields + 12} {
+		offset, length := uint64(binary.BigEndian.Uint32(data[pos:])), uint64(binary.BigEndian.Uint32(data[pos+4:]))
+		if offset == 0 {
+			if length != 0 || pos == fields && binary.BigEndian.Uint32(data[pos+8:]) != 0 {
+				return fmt.Errorf("invalid WOFF optional block")
+			}
+			continue
+		}
+		if length == 0 || offset != (end+3)&^3 || offset+length > uint64(len(data)) {
+			return fmt.Errorf("invalid WOFF block range")
+		}
+		for _, b := range data[end:offset] {
+			if b != 0 {
+				return fmt.Errorf("invalid WOFF padding")
+			}
+		}
+		end = offset + length
+	}
+	if end > uint64(len(data)) || uint64(len(data)) > (end+3)&^3 {
+		return fmt.Errorf("invalid WOFF trailing data")
+	}
+	for _, b := range data[end:] {
+		if b != 0 {
+			return fmt.Errorf("invalid WOFF padding")
+		}
+	}
+	return nil
+}

internal/base/geom/arc.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package geom
 
 import (
 	"fmt"
@@ -27,33 +27,33 @@ type geometryArc struct {
 
 // Curves 按毫米误差上限将端点式椭圆弧转换为三次贝塞尔曲线，其他指令保持原样
 // 入参: tolerance 正有限误差上限
-// 返回: GeometryPath 独立路径, error 参数错误
-func (p GeometryPath) Curves(tolerance float64) (GeometryPath, error) {
-	if err := p.validate(); err != nil {
+// 返回: Path 独立路径, error 参数错误
+func (p Path) Curves(tolerance float64) (Path, error) {
+	if err := p.Validate(); err != nil {
 		return nil, err
 	}
-	if !rasterPositive(tolerance) {
+	if !positive(tolerance) {
 		return nil, fmt.Errorf("invalid curve tolerance")
 	}
-	result := make(GeometryPath, 0, len(p))
+	result := make(Path, 0, len(p))
 	var current, start Point
 	for _, s := range p {
 		switch s.Verb {
-		case GeometryMove:
+		case Move:
 			start = s.End
-		case GeometryArc:
-			curves, err := arcCurves(current, s, tolerance)
+		case Arc:
+			curves, err := ArcCurves(current, s, tolerance)
 			if err != nil {
 				return nil, err
 			}
 			result = append(result, curves...)
 			current = s.End
 			continue
-		case GeometryClose:
+		case ClosePath:
 			result = append(result, s)
 			current = start
 			continue
-		case GeometryLine, GeometryQuad, GeometryCubic:
+		case Line, Quad, Cubic:
 		default:
 			return nil, fmt.Errorf("unsupported geometry command %d", s.Verb)
 		}
@@ -63,10 +63,10 @@ func (p GeometryPath) Curves(tolerance float64) (GeometryPath, error) {
 	return result, nil
 }
 
-// arcCurves 按标准端点参数求椭圆中心，只在绘制边界近似弧线
+// ArcCurves 按标准端点参数求椭圆中心，只在绘制边界近似弧线
 // 入参: start 起点, arc 弧线, tolerance 毫米误差上限
-// 返回: GeometryPath 贝塞尔片段, error 无效弧线
-func arcCurves(start Point, arc GeometrySegment, tolerance float64) (GeometryPath, error) {
+// 返回: Path 贝塞尔片段, error 无效弧线
+func ArcCurves(start Point, arc Segment, tolerance float64) (Path, error) {
 	a, err := centerArc(start, arc)
 	if err != nil {
 		return nil, err
@@ -75,7 +75,7 @@ func arcCurves(start Point, arc GeometrySegment, tolerance float64) (GeometryPat
 		return nil, nil
 	}
 	if arc.RadiusX == 0 || arc.RadiusY == 0 {
-		return GeometryPath{{Verb: GeometryLine, End: arc.End}}, nil
+		return Path{{Verb: Line, End: arc.End}}, nil
 	}
 	radius := math.Max(math.Hypot(a.u.X, a.u.Y), math.Hypot(a.v.X, a.v.Y))
 	step := math.Min(math.Pi/2, math.Pow(tolerance/radius*40000, 1.0/6))
@@ -88,12 +88,12 @@ func arcCurves(start Point, arc GeometrySegment, tolerance float64) (GeometryPat
 	point := func(x, y float64) Point {
 		return Point{a.center.X + a.u.X*x + a.v.X*y, a.center.Y + a.u.Y*x + a.v.Y*y}
 	}
-	result := make(GeometryPath, 0, count)
+	result := make(Path, 0, count)
 	for i := 0; i < count; i++ {
 		sa, ca := math.Sincos(a.theta + float64(i)*step)
 		sb, cb := math.Sincos(a.theta + float64(i+1)*step)
 		k := 4.0 / 3 * math.Tan(step/4)
-		result = append(result, GeometrySegment{Verb: GeometryCubic, Control1: point(ca-k*sa, sa+k*ca), Control2: point(cb+k*sb, sb-k*cb), End: point(cb, sb)})
+		result = append(result, Segment{Verb: Cubic, Control1: point(ca-k*sa, sa+k*ca), Control2: point(cb+k*sb, sb-k*cb), End: point(cb, sb)})
 	}
 	result[len(result)-1].End = arc.End
 	return result, nil
@@ -102,7 +102,7 @@ func arcCurves(start Point, arc GeometrySegment, tolerance float64) (GeometryPat
 // centerArc 将端点式圆弧解析为中心式，统一半径修正和方向语义
 // 入参: start 起点, arc 弧线
 // 返回: geometryArc 中心式参数, error 无效参数或数值溢出
-func centerArc(start Point, arc GeometrySegment) (geometryArc, error) {
+func centerArc(start Point, arc Segment) (geometryArc, error) {
 	rx, ry := arc.RadiusX, arc.RadiusY
 	if !finite(rx) || !finite(ry) || rx < 0 || ry < 0 || !finite(arc.Rotation) ||
 		!finite(start.X) || !finite(start.Y) || !finite(arc.End.X) || !finite(arc.End.Y) {
@@ -116,7 +116,7 @@ func centerArc(start Point, arc GeometrySegment) (geometryArc, error) {
 	}
 	angle := math.Mod(arc.Rotation, 360) * math.Pi / 180
 	sine, cosine := math.Sincos(angle)
-	dx, dy := (start.X-arc.End.X)/2, (start.Y-arc.End.Y)/2
+	dx, dy := arcCoordinateMean(start.X, -arc.End.X), arcCoordinateMean(start.Y, -arc.End.Y)
 	x, y := cosine*dx+sine*dy, -sine*dx+cosine*dy
 	scale := math.Hypot(x/rx, y/ry)
 	if scale > 1 {
@@ -139,13 +139,24 @@ func centerArc(start Point, arc GeometrySegment) (geometryArc, error) {
 	if !arc.Sweep && delta > 0 {
 		delta -= 2 * math.Pi
 	}
-	center := Point{cosine*cx - sine*cy + (start.X+arc.End.X)/2, sine*cx + cosine*cy + (start.Y+arc.End.Y)/2}
+	center := Point{cosine*cx - sine*cy + arcCoordinateMean(start.X, arc.End.X), sine*cx + cosine*cy + arcCoordinateMean(start.Y, arc.End.Y)}
 	if !finite(center.X) || !finite(center.Y) || !finite(rx) || !finite(ry) || !finite(delta) || !finite(theta) || delta == 0 {
 		return geometryArc{}, fmt.Errorf("invalid arc extent")
 	}
 	return geometryArc{center, Point{rx * cosine, rx * sine}, Point{-ry * sine, ry * cosine}, theta, delta}, nil
 }
 
+// arcCoordinateMean 计算有限坐标均值，仅在求和溢出时先减半，避免微小坐标提前下溢
+// 入参: a 第一个坐标, b 第二个坐标
+// 返回: float64 坐标均值
+func arcCoordinateMean(a, b float64) float64 {
+	value := (a + b) / 2
+	if math.IsInf(value, 0) {
+		return a/2 + b/2
+	}
+	return value
+}
+
 // point 计算椭圆参数对应的坐标
 // 入参: angle 参数角
 // 返回: Point 椭圆上的点

internal/base/geom/bounds.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package geom
 
 import (
 	"fmt"
@@ -22,8 +22,8 @@ import (
 // Bounds 通过解析极值计算直线、贝塞尔和椭圆弧的轴对齐边界
 // 不进行曲线展开且不使用Tolerance，结果受float64舍入误差影响，不保证向外舍入
 // 返回: Box 浮点路径范围, error 无效路径、弧线或数值溢出
-func (p GeometryPath) Bounds() (Box, error) {
-	if err := p.validate(); err != nil {
+func (p Path) Bounds() (Box, error) {
+	if err := p.Validate(); err != nil {
 		return Box{}, err
 	}
 	left, top, right, bottom := math.Inf(1), math.Inf(1), math.Inf(-1), math.Inf(-1)
@@ -34,11 +34,11 @@ func (p GeometryPath) Bounds() (Box, error) {
 	var current, start Point
 	for _, s := range p {
 		switch s.Verb {
-		case GeometryMove:
+		case Move:
 			start = s.End
-		case GeometryClose:
+		case ClosePath:
 			s.End = start
-		case GeometryArc:
+		case Arc:
 			a, err := centerArc(current, s)
 			if err != nil {
 				return Box{}, err
@@ -52,9 +52,9 @@ func (p GeometryPath) Bounds() (Box, error) {
 					}
 				}
 			}
-		case GeometryQuad, GeometryCubic:
+		case Quad, Cubic:
 			for _, axis := range [][4]float64{{current.X, s.Control1.X, s.Control2.X, s.End.X}, {current.Y, s.Control1.Y, s.Control2.Y, s.End.Y}} {
-				if s.Verb == GeometryQuad {
+				if s.Verb == Quad {
 					axis[2] = 0
 				}
 				scale := math.Max(math.Abs(axis[0]), math.Max(math.Abs(axis[1]), math.Max(math.Abs(axis[2]), math.Abs(axis[3]))))
@@ -64,19 +64,19 @@ func (p GeometryPath) Bounds() (Box, error) {
 					}
 				}
 				var roots []float64
-				if s.Verb == GeometryQuad {
+				if s.Verb == Quad {
 					roots = geometryRoots(0, axis[0]-2*axis[1]+axis[3], axis[1]-axis[0])
 				} else {
 					roots = geometryRoots(-axis[0]+3*axis[1]-3*axis[2]+axis[3], 2*(axis[0]-2*axis[1]+axis[2]), axis[1]-axis[0])
 				}
 				for _, t := range roots {
 					if t > 0 && t < 1 {
-						q := geometryLerp(current, s.Control1, t)
-						if s.Verb == GeometryQuad {
-							q = geometryLerp(q, geometryLerp(s.Control1, s.End, t), t)
+						q := Lerp(current, s.Control1, t)
+						if s.Verb == Quad {
+							q = Lerp(q, Lerp(s.Control1, s.End, t), t)
 						} else {
-							r := geometryLerp(s.Control1, s.Control2, t)
-							q = geometryLerp(geometryLerp(q, r, t), geometryLerp(r, geometryLerp(s.Control2, s.End, t), t), t)
+							r := Lerp(s.Control1, s.Control2, t)
+							q = Lerp(Lerp(q, r, t), Lerp(r, Lerp(s.Control2, s.End, t), t), t)
 						}
 						add(q)
 					}
@@ -121,9 +121,9 @@ func geometryRoots(a, b, c float64) []float64 {
 	return []float64{q / a, c / q}
 }
 
-// geometryLerp 线性插值坐标
+// Lerp 线性插值坐标
 // 入参: a 起点, b 终点, t 插值比例
 // 返回: Point 插值坐标
-func geometryLerp(a, b Point, t float64) Point {
+func Lerp(a, b Point, t float64) Point {
 	return Point{(1-t)*a.X + t*b.X, (1-t)*a.Y + t*b.Y}
 }

internal/base/geom/clip.go

@@ -0,0 +1,129 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package geom
+
+import "math"
+
+// polygonPoint 允许同结构的后端顶点直接参与裁剪，避免整片坐标转换
+type polygonPoint interface {
+	~struct{ X, Y float64 }
+}
+
+// ClipPolygon 按非退化凸窗口逐边裁剪多边形，保留原顶点绕向，不修改输入
+// 入参: a 绘制顶点, b 已通过ConvexPolygon检查的裁剪顶点，均不含重复闭合点
+// 返回: []P 交集顶点，少于三个顶点时不构成区域, bool 是否满足数值精度
+func ClipPolygon[P polygonPoint](a, b []P) ([]P, bool) {
+	for i, start := range b {
+		origin, end := Point(start), Point(b[(i+1)%len(b)])
+		dx, dy := end.X-origin.X, end.Y-origin.Y
+		length := math.Hypot(dx, dy)
+		if length == 0 {
+			continue
+		}
+		dx, dy = dx/length, dy/length
+		distance := func(p P) float64 { return convexDistance(origin, Point(p), dx, dy) }
+		sign := 1.0
+		for _, p := range b {
+			if d := distance(p); d != 0 {
+				sign = math.Copysign(1, d)
+				break
+			}
+		}
+		if len(a) == 0 {
+			break
+		}
+		var clipped []P
+		appendPoint := func(p P) {
+			if len(clipped) == 0 || p != clipped[len(clipped)-1] {
+				clipped = append(clipped, p)
+			}
+		}
+		previous := a[len(a)-1]
+		previousDistance := sign * distance(previous)
+		if !finite(previousDistance) {
+			return nil, false
+		}
+		for _, p := range a {
+			d := sign * distance(p)
+			if !finite(d) {
+				return nil, false
+			}
+			if (d >= 0) != (previousDistance >= 0) {
+				scale := math.Max(math.Abs(d), math.Abs(previousDistance))
+				fraction := (previousDistance / scale) / (previousDistance/scale - d/scale)
+				intersection := Lerp(Point(previous), Point(p), fraction)
+				if dx == 0 {
+					intersection.X = origin.X
+				}
+				if dy == 0 {
+					intersection.Y = origin.Y
+				}
+				appendPoint(P(intersection))
+			}
+			if d >= 0 {
+				appendPoint(p)
+			}
+			previous, previousDistance = p, d
+		}
+		if len(clipped) > 1 && clipped[0] == clipped[len(clipped)-1] {
+			clipped = clipped[:len(clipped)-1]
+		}
+		a = clipped
+	}
+	return a, true
+}
+
+// ConvexPolygon 检查所有顶点位于各边的同一侧，不修改输入
+// 入参: points 不含重复闭合点的独立顶点
+// 返回: []P 原顶点，非有限距离或异侧顶点返回nil, bool 是否为非退化凸多边形
+func ConvexPolygon[P polygonPoint](points []P) ([]P, bool) {
+	positive := false
+	for i, start := range points {
+		origin, end := Point(start), Point(points[(i+1)%len(points)])
+		dx, dy := end.X-origin.X, end.Y-origin.Y
+		length := math.Hypot(dx, dy)
+		if !finite(length) {
+			return nil, false
+		}
+		if length == 0 {
+			continue
+		}
+		dx, dy = dx/length, dy/length
+		sign := 0.0
+		for _, p := range points {
+			d := convexDistance(origin, Point(p), dx, dy)
+			if !finite(d) || sign*d < 0 {
+				return nil, false
+			}
+			if d != 0 {
+				sign, positive = math.Copysign(1, d), true
+			}
+		}
+	}
+	return points, positive
+}
+
+// convexDistance 按浮点乘法误差界识别共线点，不使用固定坐标容差
+// 入参: start 边起点, point 待测顶点, dx 横向单位分量, dy 纵向单位分量
+// 返回: float64 顶点到边的有向距离
+func convexDistance(start, point Point, dx, dy float64) float64 {
+	x, y := point.X-start.X, point.Y-start.Y
+	distance := math.FMA(dx, y, -dy*x)
+	errorBound := (math.Abs(dx*y) + math.Abs(dy*x)) * 0x1p-49
+	if finite(errorBound) && math.Abs(distance) <= errorBound {
+		return 0
+	}
+	return distance
+}

internal/base/geom/contain.go

@@ -12,14 +12,16 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package geom
 
-import "math"
+import (
+	"math"
+)
 
-// geometryConvexContains 判断单个非退化凸直线区域是否包含另一闭合直线区域
+// ConvexContains 判断单个非退化凸直线区域是否包含另一闭合直线区域
 // 入参: outer 外部区域, inner 内部区域
 // 返回: bool 是否完全包含，曲线及多轮廓返回false
-func geometryConvexContains(outer, inner GeometryPath) bool {
+func ConvexContains(outer, inner Path) bool {
 	a, b := geometryPolygonPoints(outer), geometryPolygonPoints(inner)
 	if len(a) < 3 || len(b) < 3 {
 		return false
@@ -68,12 +70,12 @@ func geometryConvexContains(outer, inner GeometryPath) bool {
 // geometryPolygonPoints 读取单个显式闭合直线轮廓的顶点，不修改原路径
 // 入参: path 直线轮廓
 // 返回: []Point 独立顶点，其他路径返回nil
-func geometryPolygonPoints(path GeometryPath) []Point {
-	if len(path) < 4 || path[0].Verb != GeometryMove || path[len(path)-1].Verb != GeometryClose {
+func geometryPolygonPoints(path Path) []Point {
+	if len(path) < 4 || path[0].Verb != Move || path[len(path)-1].Verb != ClosePath {
 		return nil
 	}
 	for i, segment := range path[:len(path)-1] {
-		if i > 0 && segment.Verb != GeometryLine || !finite(segment.End.X) || !finite(segment.End.Y) {
+		if i > 0 && segment.Verb != Line || !finite(segment.End.X) || !finite(segment.End.Y) {
 			return nil
 		}
 	}

internal/base/geom/matrix.go

@@ -0,0 +1,197 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package geom
+
+import (
+	"math"
+)
+
+// IdentityMatrix 单位矩阵
+var IdentityMatrix = Matrix{1, 0, 0, 1, 0, 0}
+
+// Box 矩形区域
+type Box struct {
+	X, Y, W, H float64
+}
+
+// Point 平面坐标点
+type Point struct {
+	X, Y float64
+}
+
+// Matrix 2D仿射变换矩阵
+type Matrix struct {
+	a, b, c, d, e, f float64
+}
+
+// MatrixFromValues 从a、b、c、d、e、f构造矩阵，不经过文本格式化
+// 入参: values 矩阵分量
+// 返回: Matrix 变换矩阵
+func MatrixFromValues(values [6]float64) Matrix {
+	return Matrix{a: values[0], b: values[1], c: values[2], d: values[3], e: values[4], f: values[5]}
+}
+
+// Values 返回a、b、c、d、e、f的独立副本，保留原始浮点精度
+// 返回: [6]float64 矩阵分量
+func (m Matrix) Values() [6]float64 {
+	return [6]float64{m.a, m.b, m.c, m.d, m.e, m.f}
+}
+
+// Multiply 矩阵乘法 (m * o)
+// 入参: o 右侧矩阵
+// 返回: Matrix 结果矩阵
+func (m Matrix) Multiply(o Matrix) Matrix {
+	return Matrix{
+		a: m.a*o.a + m.c*o.b,
+		b: m.b*o.a + m.d*o.b,
+		c: m.a*o.c + m.c*o.d,
+		d: m.b*o.c + m.d*o.d,
+		e: m.a*o.e + m.c*o.f + m.e,
+		f: m.b*o.e + m.d*o.f + m.f,
+	}
+}
+
+// Transform 应用变换矩阵
+// 入参: x X坐标, y Y坐标
+// 返回: float64 变换后X, float64 变换后Y
+func (m Matrix) Transform(x, y float64) (float64, float64) {
+	nx := m.a*x + m.c*y + m.e
+	ny := m.b*x + m.d*y + m.f
+	return nx, ny
+}
+
+// TransformBox 获取矩形经仿射变换后的轴对齐边界
+// 入参: box 原始矩形范围
+// 返回: Box 变换后的轴对齐边界
+func (m Matrix) TransformBox(box Box) Box {
+	x, y := m.Transform(box.X, box.Y)
+	left, top, right, bottom := x, y, x, y
+	for _, point := range [][2]float64{{box.X + box.W, box.Y}, {box.X, box.Y + box.H}, {box.X + box.W, box.Y + box.H}} {
+		x, y := m.Transform(point[0], point[1])
+		left, top, right, bottom = math.Min(left, x), math.Min(top, y), math.Max(right, x), math.Max(bottom, y)
+	}
+	return Box{X: left, Y: top, W: right - left, H: bottom - top}
+}
+
+// Invert 求仿射矩阵的逆变换
+// 返回: Matrix 逆矩阵，失败时返回单位矩阵, bool 是否存在有限逆矩阵
+func (m Matrix) Invert() (Matrix, bool) {
+	for _, value := range m.Values() {
+		if !finite(value) {
+			return IdentityMatrix, false
+		}
+	}
+	det, ds := matrixProductDifference(m.a, m.d, m.b, m.c)
+	x, xs := matrixProductDifference(m.c, m.f, m.d, m.e)
+	y, ys := matrixProductDifference(m.b, m.e, m.a, m.f)
+	if det != 0 && ds && xs && ys {
+		n := Matrix{a: m.d / det, b: -m.b / det, c: -m.c / det, d: m.a / det, e: x / det, f: y / det}
+		valid := true
+		for _, value := range n.Values() {
+			valid = valid && finite(value)
+		}
+		if valid {
+			return n, true
+		}
+	}
+	determinant, exponent := matrixProductSum(m.a, m.d, -m.b, m.c)
+	if determinant == 0 {
+		return IdentityMatrix, false
+	}
+	divide := func(value float64, power int) float64 {
+		mantissa, shift := math.Frexp(value)
+		return math.Ldexp(mantissa/determinant, power+shift-exponent)
+	}
+	x, xe := matrixProductSum(m.c, m.f, -m.d, m.e)
+	y, ye := matrixProductSum(m.b, m.e, -m.a, m.f)
+	n := Matrix{a: divide(m.d, 0), b: divide(-m.b, 0), c: divide(-m.c, 0), d: divide(m.a, 0), e: divide(x, xe), f: divide(y, ye)}
+	for _, value := range n.Values() {
+		if !finite(value) {
+			return IdentityMatrix, false
+		}
+	}
+	return n, true
+}
+
+// matrixProductDifference 补偿乘积相减的舍入残差，检查溢出、下溢及严重相消
+// 入参: a 第一个乘数, b 第二个乘数, c 第三个乘数, d 第四个乘数
+// 返回: float64 乘积之差, bool 是否可直接用于求逆
+func matrixProductDifference(a, b, c, d float64) (float64, bool) {
+	x, y := a*b, c*d
+	value := x - y
+	if !finite(value) || x == 0 && a != 0 && b != 0 || y == 0 && c != 0 && d != 0 {
+		return value, false
+	}
+	if x != 0 && y != 0 {
+		value = math.FMA(a, b, -y) + math.FMA(-c, d, y)
+	}
+	return value, x == 0 && y == 0 || math.Abs(value) >= 0x1p-1022 && math.Abs(value) >= 0x1p-48*math.Max(math.Abs(x), math.Abs(y))
+}
+
+// matrixProductSum 以尾数及指数累加两个乘积，保留乘法舍入残差
+// 入参: a 第一个乘数, b 第二个乘数, c 第三个乘数, d 第四个乘数
+// 返回: float64 结果尾数, int 二进制指数
+func matrixProductSum(a, b, c, d float64) (float64, int) {
+	a, ae := math.Frexp(a)
+	b, be := math.Frexp(b)
+	c, ce := math.Frexp(c)
+	d, de := math.Frexp(d)
+	x, y := a*b, c*d
+	xe, ye := ae+be, ce+de
+	power := max(xe, ye)
+	if x == 0 {
+		power = ye
+	} else if y == 0 {
+		power = xe
+	}
+	value := math.Ldexp(x, xe-power) + math.Ldexp(y, ye-power)
+	value += math.Ldexp(math.FMA(a, b, -x), xe-power) + math.Ldexp(math.FMA(c, d, -y), ye-power)
+	value, shift := math.Frexp(value)
+	return value, power + shift
+}
+
+// TranslationMatrix 构造平移矩阵
+// 入参: x X轴偏移, y Y轴偏移
+// 返回: Matrix 平移矩阵
+func TranslationMatrix(x, y float64) Matrix {
+	return Matrix{a: 1, d: 1, e: x, f: y}
+}
+
+// YScale 获取Y轴缩放比例
+// 返回: float64 缩放比例
+func (m Matrix) YScale() float64 {
+	return math.Hypot(m.c, m.d)
+}
+
+// Equal 比较毫米坐标，使用固定绝对误差，不受绘图库全局精度影响
+// 入参: a 第一个坐标, b 第二个坐标
+// 返回: bool 是否在容差内相等
+func Equal(a, b float64) bool {
+	return math.Abs(a-b) <= 1e-10
+}
+
+// AxisAligned 判断变换是否保持坐标轴平行，含直角旋转与镜像
+// 入参: m 仿射变换矩阵
+// 返回: bool 是否为非退化的轴对齐变换
+func AxisAligned(m Matrix) bool {
+	return m.b == 0 && m.c == 0 && m.a != 0 && m.d != 0 || m.a == 0 && m.d == 0 && m.b != 0 && m.c != 0
+}
+
+// Vector 变换位移，不包含平移分量
+// 入参: m 仿射变换矩阵, x 原始横向位移, y 原始纵向位移
+// 返回: float64 变换后的X位移, float64 变换后的Y位移
+func Vector(m Matrix, x, y float64) (float64, float64) {
+	return m.a*x + m.c*y, m.b*x + m.d*y
+}

internal/base/geom/number.go

@@ -0,0 +1,31 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package geom
+
+import (
+	"math"
+)
+
+// finite 判断数值是否有限
+// 入参: value 数值
+// 返回: bool 是否有限
+func finite(value float64) bool {
+	return !math.IsNaN(value) && !math.IsInf(value, 0)
+}
+
+// positive 判断正有限数
+// 入参: v 待检查数值
+// 返回: bool 是否为正有限数
+func positive(v float64) bool { return v > 0 && !math.IsInf(v, 0) && !math.IsNaN(v) }

internal/base/geom/path.go

@@ -0,0 +1,160 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package geom
+
+import (
+	"fmt"
+	"math"
+)
+
+// 几何路径指令，包括直线、曲线、椭圆弧和闭合
+const (
+	Move Verb = iota
+	Line
+	Quad
+	Cubic
+	Arc
+	ClosePath
+)
+
+// Path 保存独立于绘图库的几何路径，不扁平化曲线或舍入坐标
+// 坐标以左上角为原点，单位为毫米，子路径从Move开始，Close回到当前子路径起点
+type Path []Segment
+
+// Verb 表示几何路径指令
+type Verb uint8
+
+// Segment 保存路径端点、贝塞尔控制点或端点式椭圆弧参数
+// 弧线Rotation单位为度，Sweep为true表示顺时针，Large表示大弧
+type Segment struct {
+	Verb               Verb
+	End                Point
+	Control1, Control2 Point
+	RadiusX, RadiusY   float64
+	Rotation           float64
+	Large, Sweep       bool
+}
+
+// StrokeOptions 描述描边参数，长度与路径坐标采用相同单位
+// Width须为正有限数；Cap和Join使用标准线帽和连接样式名称，空值分别采用Butt和Miter
+// MiterLimit为尖角长度与半线宽的比值上限，由调用方设置默认值
+// MiterLimitSet供调用方区分显式零值与默认值，不参与几何计算
+// DashOffset为虚线起始偏移，允许负值；Dashes交替指定实线段和间隔长度，奇数项按重复一遍处理
+// Tolerance为曲线展开的误差目标，0采用0.001
+type StrokeOptions struct {
+	Width         float64
+	Cap, Join     string
+	MiterLimit    float64
+	MiterLimitSet bool
+	DashOffset    float64
+	Tolerance     float64
+	Dashes        []float64
+}
+
+// Close 为填充轮廓补齐隐式闭合边，不改变源路径
+// 入参: path 填充路径
+// 返回: Path 显式闭合路径
+func Close(path Path) Path {
+	open, missing := false, false
+	for _, segment := range path {
+		if segment.Verb == Move && open {
+			missing = true
+			break
+		}
+		open = segment.Verb != ClosePath
+	}
+	if !missing && !open {
+		return path
+	}
+	result := make(Path, 0, len(path)+1)
+	open = false
+	for _, segment := range path {
+		if segment.Verb == Move && open {
+			result = append(result, Segment{Verb: ClosePath})
+		}
+		result = append(result, segment)
+		open = segment.Verb != ClosePath
+	}
+	if open {
+		result = append(result, Segment{Verb: ClosePath})
+	}
+	return result
+}
+
+// ValidateStroke 校验各后端共用的描边参数
+// 入参: options 描边样式
+// 返回: error 无效样式
+func ValidateStroke(options StrokeOptions) error {
+	if !finite(options.Width) || options.Width <= 0 || !finite(options.Tolerance) || options.Tolerance < 0 || !finite(options.DashOffset) || !finite(options.MiterLimit) || options.MiterLimit < 0 {
+		return fmt.Errorf("invalid stroke width or tolerance")
+	}
+	if options.Cap != "" && options.Cap != "Butt" && options.Cap != "Round" && options.Cap != "Square" {
+		return fmt.Errorf("invalid stroke cap %q", options.Cap)
+	}
+	if options.Join != "" && options.Join != "Miter" && options.Join != "Round" && options.Join != "Bevel" {
+		return fmt.Errorf("invalid stroke join %q", options.Join)
+	}
+	for _, dash := range options.Dashes {
+		if !finite(dash) || dash < 0 {
+			return fmt.Errorf("invalid stroke dash")
+		}
+	}
+	return nil
+}
+
+// Rectangle 构建页面坐标矩形，保留输入精度
+// 入参: box 矩形范围
+// 返回: Path 闭合路径
+func Rectangle(box Box) Path {
+	return Path{
+		{Verb: Move, End: Point{X: box.X, Y: box.Y}},
+		{Verb: Line, End: Point{X: box.X + box.W, Y: box.Y}},
+		{Verb: Line, End: Point{X: box.X + box.W, Y: box.Y + box.H}},
+		{Verb: Line, End: Point{X: box.X, Y: box.Y + box.H}},
+		{Verb: ClosePath, End: Point{X: box.X, Y: box.Y}},
+	}
+}
+
+// RectangleBounds 识别单个轴对齐矩形，不用包围盒代替实际路径
+// 入参: path 填充路径
+// 返回: Box 矩形范围, bool 是否为非退化矩形
+func RectangleBounds(path Path) (Box, bool) {
+	if len(path) > 0 && path[len(path)-1].Verb == ClosePath {
+		path = path[:len(path)-1]
+	}
+	if len(path) == 5 && path[4].Verb == Line && path[4].End == path[0].End {
+		path = path[:4]
+	}
+	if len(path) != 4 || path[0].Verb != Move || path[1].Verb != Line || path[2].Verb != Line || path[3].Verb != Line {
+		return Box{}, false
+	}
+	a, b, c, d := path[0].End, path[1].End, path[2].End, path[3].End
+	for _, point := range [...]Point{a, b, c, d} {
+		if !finite(point.X) || !finite(point.Y) {
+			return Box{}, false
+		}
+	}
+	if a.X == c.X || a.Y == c.Y {
+		return Box{}, false
+	}
+	if !(a.X == b.X && b.Y == c.Y && c.X == d.X && d.Y == a.Y || a.Y == b.Y && b.X == c.X && c.Y == d.Y && d.X == a.X) {
+		return Box{}, false
+	}
+	width, height := math.Abs(c.X-a.X), math.Abs(c.Y-a.Y)
+	if !finite(width) || !finite(height) {
+		return Box{}, false
+	}
+	return Box{X: min(a.X, c.X), Y: min(a.Y, c.Y), W: width, H: height}, true
+}

internal/base/geom/stroke.go

@@ -12,13 +12,17 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package geom
 
 import (
 	"fmt"
 	"math"
+	"slices"
 )
 
+// UnsupportedError 表示当前几何实现无法展开的描边形态
+type UnsupportedError string
+
 // geometryPolyline 保存展开后的子路径，独立记录闭合状态
 type geometryPolyline struct {
 	points    []Point
@@ -26,16 +30,22 @@ type geometryPolyline struct {
 	direction Point
 }
 
-// Stroke 将曲线、虚线及线帽连接转换为非零填充轮廓
+// Error 返回不支持的描边原因
+// 返回: string 错误信息
+func (err UnsupportedError) Error() string {
+	return string(err)
+}
+
+// Stroke 按端点和转角样式将曲线、虚线转换为非零填充轮廓
 // 曲线按Tolerance展开，默认误差为0.001毫米，重叠轮廓保持同向绕数
 // 结果未做布尔整理，按非零规则填充，区域运算需能处理重叠子路径的后端
 // 入参: options 描边样式
-// 返回: GeometryPath 描边轮廓, error 无效参数或精度限制
-func (p GeometryPath) Stroke(options StrokeOptions) (GeometryPath, error) {
-	if err := validateStroke(options); err != nil {
+// 返回: Path 描边轮廓, error 无效参数或精度限制
+func (p Path) Stroke(options StrokeOptions) (Path, error) {
+	if err := ValidateStroke(options); err != nil {
 		return nil, err
 	}
-	if err := p.validate(); err != nil {
+	if err := p.Validate(); err != nil {
 		return nil, err
 	}
 	if options.Width/2 == 0 {
@@ -68,7 +78,7 @@ func (p GeometryPath) Stroke(options StrokeOptions) (GeometryPath, error) {
 	if err != nil {
 		return nil, err
 	}
-	var result GeometryPath
+	var result Path
 	for _, line := range lines {
 		parts := []geometryPolyline{line}
 		if len(dashes) != 0 {
@@ -87,7 +97,7 @@ func (p GeometryPath) Stroke(options StrokeOptions) (GeometryPath, error) {
 			}
 		}
 	}
-	if err := result.validate(); err != nil {
+	if err := result.Validate(); err != nil {
 		return nil, err
 	}
 	return result, nil
@@ -96,7 +106,7 @@ func (p GeometryPath) Stroke(options StrokeOptions) (GeometryPath, error) {
 // strokePolylines 自适应展开贝塞尔，弦长亏损同时约束虚线累计长度误差
 // 入参: tolerance 展开误差
 // 返回: []geometryPolyline 子路径, error 展开限制
-func (p GeometryPath) strokePolylines(tolerance float64) ([]geometryPolyline, error) {
+func (p Path) strokePolylines(tolerance float64) ([]geometryPolyline, error) {
 	curves, err := p.Curves(tolerance / 2)
 	if err != nil {
 		return nil, err
@@ -144,26 +154,26 @@ func (p GeometryPath) strokePolylines(tolerance float64) ([]geometryPolyline, er
 		if depth == 24 {
 			return fmt.Errorf("stroke curve tolerance cannot be met")
 		}
-		work := append([]Point(nil), points...)
-		left, right := make([]Point, len(points)), make([]Point, len(points))
+		var work, left, right [4]Point
+		copy(work[:], points)
 		for n := len(points); n > 0; n-- {
 			left[len(points)-n], right[n-1] = work[0], work[n-1]
 			for i := 0; i < n-1; i++ {
-				work[i] = geometryLerp(work[i], work[i+1], .5)
+				work[i] = Lerp(work[i], work[i+1], .5)
 			}
 		}
-		if err := flatten(left, budget/2, depth+1); err != nil {
+		if err := flatten(left[:len(points)], budget/2, depth+1); err != nil {
 			return err
 		}
-		return flatten(right, budget/2, depth+1)
+		return flatten(right[:len(points)], budget/2, depth+1)
 	}
 	for _, s := range curves {
 		switch s.Verb {
-		case GeometryMove:
+		case Move:
 			flush()
 			current, start = s.End, s.End
 			line.points = []Point{current}
-		case GeometryClose:
+		case ClosePath:
 			if drawn {
 				if current != start {
 					line.points = append(line.points, start)
@@ -175,11 +185,12 @@ func (p GeometryPath) strokePolylines(tolerance float64) ([]geometryPolyline, er
 			line.points = []Point{current}
 		default:
 			drawn = true
-			points := []Point{current}
-			if s.Verb == GeometryQuad || s.Verb == GeometryCubic {
+			var buffer [4]Point
+			points := append(buffer[:0], current)
+			if s.Verb == Quad || s.Verb == Cubic {
 				points = append(points, s.Control1)
 			}
-			if s.Verb == GeometryCubic {
+			if s.Verb == Cubic {
 				points = append(points, s.Control2)
 			}
 			points = append(points, s.End)
@@ -236,7 +247,7 @@ func (line geometryPolyline) dash(pattern []float64, total, offset float64) ([]g
 					return nil, fmt.Errorf("stroke dash subdivision limit exceeded")
 				}
 				if pattern[index] == 0 && index%2 == 0 && len(run) == 0 {
-					result = append(result, geometryPolyline{points: []Point{geometryLerp(a, b, at/length)}, direction: Point{(b.X - a.X) / length, (b.Y - a.Y) / length}})
+					result = append(result, geometryPolyline{points: []Point{Lerp(a, b, at/length)}, direction: Point{(b.X - a.X) / length, (b.Y - a.Y) / length}})
 				}
 				index = (index + 1) % len(pattern)
 				remaining = pattern[index]
@@ -254,10 +265,10 @@ func (line geometryPolyline) dash(pattern []float64, total, offset float64) ([]g
 			steps++
 			if index%2 == 0 {
 				if len(run) == 0 {
-					run = append(run, geometryLerp(a, b, at/length))
+					run = append(run, Lerp(a, b, at/length))
 					direction = Point{(b.X - a.X) / length, (b.Y - a.Y) / length}
 				}
-				end := geometryLerp(a, b, (at+step)/length)
+				end := Lerp(a, b, (at+step)/length)
 				if end != run[len(run)-1] {
 					run = append(run, end)
 				}
@@ -283,8 +294,8 @@ func (line geometryPolyline) dash(pattern []float64, total, offset float64) ([]g
 
 // stroke 追加同向矩形、连接楔形及圆盘组成的非零填充区域
 // 入参: result 已有轮廓, options 描边样式
-// 返回: GeometryPath 填充轮廓, error 不支持的退化方形线帽
-func (line geometryPolyline) stroke(result GeometryPath, options StrokeOptions) (GeometryPath, error) {
+// 返回: Path 填充轮廓, error 不支持的退化方头端点
+func (line geometryPolyline) stroke(result Path, options StrokeOptions) (Path, error) {
 	half := options.Width / 2
 	polygon := func(points ...Point) {
 		scale := 0.0
@@ -307,29 +318,29 @@ func (line geometryPolyline) stroke(result GeometryPath, options StrokeOptions)
 				points[i], points[j] = points[j], points[i]
 			}
 		}
-		result = append(result, GeometrySegment{Verb: GeometryMove, End: points[0]})
+		result = append(result, Segment{Verb: Move, End: points[0]})
 		for _, p := range points[1:] {
-			result = append(result, GeometrySegment{Verb: GeometryLine, End: p})
+			result = append(result, Segment{Verb: Line, End: p})
 		}
-		result = append(result, GeometrySegment{Verb: GeometryClose})
+		result = append(result, Segment{Verb: ClosePath})
 	}
 	disk := func(p Point) {
-		result = append(result, GeometrySegment{Verb: GeometryMove, End: Point{p.X + half, p.Y}},
-			GeometrySegment{Verb: GeometryArc, RadiusX: half, RadiusY: half, Sweep: true, End: Point{p.X - half, p.Y}},
-			GeometrySegment{Verb: GeometryArc, RadiusX: half, RadiusY: half, Sweep: true, End: Point{p.X + half, p.Y}},
-			GeometrySegment{Verb: GeometryClose})
+		result = append(result, Segment{Verb: Move, End: Point{p.X + half, p.Y}},
+			Segment{Verb: Arc, RadiusX: half, RadiusY: half, Sweep: true, End: Point{p.X - half, p.Y}},
+			Segment{Verb: Arc, RadiusX: half, RadiusY: half, Sweep: true, End: Point{p.X + half, p.Y}},
+			Segment{Verb: ClosePath})
 	}
 	points := line.points
 	if len(points) == 1 {
 		if line.closed {
-			return nil, fmt.Errorf("directionless closed stroke: %w", ErrBackendUnavailable)
+			return nil, UnsupportedError("directionless closed stroke")
 		}
 		if options.Cap == "Round" {
 			disk(points[0])
 		} else if options.Cap == "Square" {
 			d := line.direction
 			if d == (Point{}) {
-				return nil, fmt.Errorf("directionless square stroke cap: %w", ErrBackendUnavailable)
+				return nil, UnsupportedError("directionless square stroke cap")
 			}
 			p := points[0]
 			u, v := Point{d.X * half, d.Y * half}, Point{-d.Y * half, d.X * half}
@@ -337,7 +348,22 @@ func (line geometryPolyline) stroke(result GeometryPath, options StrokeOptions)
 		}
 		return result, nil
 	}
-	directions := make([]Point, len(points)-1)
+	segments := len(points) - 1
+	joins := segments - 1
+	caps := 0
+	if line.closed {
+		joins++
+	} else if options.Cap == "Round" {
+		caps = 8
+	} else if options.Cap == "Square" {
+		caps = 10
+	}
+	joinSize := 4
+	if options.Join == "" || options.Join == "Miter" {
+		joinSize = 5
+	}
+	result = slices.Grow(result, min(segments*5+joins*joinSize+caps, 1<<20-len(result)))
+	directions := make([]Point, segments)
 	for i := range directions {
 		a, b := points[i], points[i+1]
 		length := math.Hypot(b.X-a.X, b.Y-a.Y)
@@ -364,16 +390,13 @@ func (line geometryPolyline) stroke(result GeometryPath, options StrokeOptions)
 			if cross < 0 {
 				x, y = y, x
 			}
-			result = append(result, GeometrySegment{Verb: GeometryMove, End: p},
-				GeometrySegment{Verb: GeometryLine, End: x},
-				GeometrySegment{Verb: GeometryArc, RadiusX: half, RadiusY: half, Sweep: true, End: y},
-				GeometrySegment{Verb: GeometryClose})
+			result = append(result, Segment{Verb: Move, End: p},
+				Segment{Verb: Line, End: x},
+				Segment{Verb: Arc, RadiusX: half, RadiusY: half, Sweep: true, End: y},
+				Segment{Verb: ClosePath})
 			return
 		}
 		limit := options.MiterLimit
-		if limit == 0 {
-			limit = defaultMiterLimit
-		}
 		if options.Join == "" || options.Join == "Miter" {
 			t := ((y.X-x.X)*b.Y - (y.Y-x.Y)*b.X) / cross
 			m := Point{x.X + t*a.X, x.Y + t*a.Y}

internal/base/geom/transform.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package geom
 
 import (
 	"fmt"
@@ -22,9 +22,9 @@ import (
 
 // Transform 精确变换控制点和椭圆轴，退化弧沿投影极值分段保留折返
 // 入参: matrix 仿射变换
-// 返回: GeometryPath 独立路径, error 无效路径或数值溢出
-func (p GeometryPath) Transform(matrix Matrix) (GeometryPath, error) {
-	if err := p.validate(); err != nil {
+// 返回: Path 独立路径, error 无效路径或数值溢出
+func (p Path) Transform(matrix Matrix) (Path, error) {
+	if err := p.Validate(); err != nil {
 		return nil, err
 	}
 	for _, value := range matrix.Values() {
@@ -33,17 +33,14 @@ func (p GeometryPath) Transform(matrix Matrix) (GeometryPath, error) {
 		}
 	}
 	matrixScale := math.Max(math.Max(math.Abs(matrix.a), math.Abs(matrix.b)), math.Max(math.Abs(matrix.c), math.Abs(matrix.d)))
-	determinant := 0.0
-	if matrixScale != 0 {
-		determinant = (matrix.a/matrixScale)*(matrix.d/matrixScale) - (matrix.b/matrixScale)*(matrix.c/matrixScale)
-	}
+	determinant, _ := matrixProductSum(matrix.a, matrix.d, -matrix.b, matrix.c)
 	transform := func(p Point) Point {
 		x, y := matrix.Transform(p.X, p.Y)
 		return Point{x, y}
 	}
-	var result GeometryPath
+	var result Path
 	if len(p) > 0 {
-		result = make(GeometryPath, 0, len(p))
+		result = make(Path, 0, len(p))
 	}
 	var current, start Point
 	for _, s := range p {
@@ -51,15 +48,15 @@ func (p GeometryPath) Transform(matrix Matrix) (GeometryPath, error) {
 		original := s.End
 		s.End = transform(s.End)
 		switch s.Verb {
-		case GeometryMove:
+		case Move:
 			start = original
-		case GeometryQuad:
+		case Quad:
 			s.Control1 = transform(s.Control1)
-		case GeometryCubic:
+		case Cubic:
 			s.Control1, s.Control2 = transform(s.Control1), transform(s.Control2)
-		case GeometryClose:
+		case ClosePath:
 			original, s.End = start, transform(start)
-		case GeometryArc:
+		case Arc:
 			a, err := centerArc(current, originalSegment)
 			if err != nil {
 				return nil, err
@@ -69,11 +66,11 @@ func (p GeometryPath) Transform(matrix Matrix) (GeometryPath, error) {
 				continue
 			}
 			if s.RadiusX == 0 || s.RadiusY == 0 {
-				s = GeometrySegment{Verb: GeometryLine, End: s.End}
+				s = Segment{Verb: Line, End: s.End}
 			} else {
 				a.center = transform(a.center)
-				a.u.X, a.u.Y = matrixVector(matrix, a.u.X, a.u.Y)
-				a.v.X, a.v.Y = matrixVector(matrix, a.v.X, a.v.Y)
+				a.u.X, a.u.Y = Vector(matrix, a.u.X, a.u.Y)
+				a.v.X, a.v.Y = Vector(matrix, a.v.X, a.v.Y)
 				scale := math.Max(math.Hypot(a.u.X, a.u.Y), math.Hypot(a.v.X, a.v.Y))
 				if !finite(scale) {
 					return nil, fmt.Errorf("arc transform overflow")
@@ -82,7 +79,7 @@ func (p GeometryPath) Transform(matrix Matrix) (GeometryPath, error) {
 					if matrixScale != 0 {
 						return nil, fmt.Errorf("arc transform precision exhausted")
 					}
-					s = GeometrySegment{Verb: GeometryLine, End: s.End}
+					s = Segment{Verb: Line, End: s.End}
 				} else {
 					ux, uy, vx, vy := a.u.X/scale, a.u.Y/scale, a.v.X/scale, a.v.Y/scale
 					det := ux*vy - uy*vx
@@ -100,9 +97,9 @@ func (p GeometryPath) Transform(matrix Matrix) (GeometryPath, error) {
 						}
 						slices.Sort(fractions)
 						for _, f := range slices.Compact(fractions) {
-							result = append(result, GeometrySegment{Verb: GeometryLine, End: a.point(a.theta + f*a.delta)})
+							result = append(result, Segment{Verb: Line, End: a.point(a.theta + f*a.delta)})
 						}
-						s = GeometrySegment{Verb: GeometryLine, End: s.End}
+						s = Segment{Verb: Line, End: s.End}
 					} else {
 						xx, yy, xy := ux*ux+vx*vx, uy*uy+vy*vy, ux*uy+vx*vy
 						radius := math.Sqrt((xx + yy + math.Hypot(xx-yy, 2*xy)) / 2)
@@ -121,32 +118,32 @@ func (p GeometryPath) Transform(matrix Matrix) (GeometryPath, error) {
 		result = append(result, s)
 		current = original
 	}
-	if err := result.validate(); err != nil {
+	if err := result.Validate(); err != nil {
 		return nil, err
 	}
 	return result, nil
 }
 
-// validate 校验公共路径指令、子路径起点和有限坐标
+// Validate 校验公共路径指令、子路径起点和有限坐标
 // 返回: error 无效路径
-func (p GeometryPath) validate() error {
+func (p Path) Validate() error {
 	started := false
 	for _, s := range p {
 		points := [3]Point{s.End, s.Control1, s.Control2}
 		count := 1
 		switch s.Verb {
-		case GeometryMove:
+		case Move:
 			started = true
-		case GeometryLine:
-		case GeometryQuad:
+		case Line:
+		case Quad:
 			count = 2
-		case GeometryCubic:
+		case Cubic:
 			count = 3
-		case GeometryArc:
+		case Arc:
 			if !finite(s.RadiusX) || !finite(s.RadiusY) || !finite(s.Rotation) || s.RadiusX < 0 || s.RadiusY < 0 {
 				return fmt.Errorf("invalid arc parameters")
 			}
-		case GeometryClose:
+		case ClosePath:
 			count = 0
 		default:
 			return fmt.Errorf("unsupported geometry command %d", s.Verb)

internal/base/image/bmp.go

@@ -0,0 +1,125 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package image
+
+import (
+	"bufio"
+	"encoding/binary"
+	"fmt"
+	"image"
+	"io"
+	"math/bits"
+)
+
+// bmpColorMask 保存一个BMP颜色分量的位域位置和取值范围
+type bmpColorMask struct {
+	mask  uint32
+	shift uint
+	Max   uint32
+}
+
+// DecodeConfig 读取图片尺寸，BMP和TIFF只读取布局信息，不解码像素
+// 入参: input 图片输入流
+// 返回: image.Config 图片配置, string 图片格式, error 头部错误
+func DecodeConfig(input io.Reader) (image.Config, string, error) {
+	buffer := bufio.NewReader(input)
+	prefix, _ := buffer.Peek(34)
+	if IsTIFF(prefix) {
+		layout, err := readTIFFLayout(buffer)
+		if err != nil {
+			return image.Config{}, "tiff", err
+		}
+		size := layout.DisplaySize()
+		return image.Config{Width: size.X, Height: size.Y}, "tiff", nil
+	}
+	if len(prefix) == 34 && string(prefix[:2]) == "BM" {
+		header := binary.LittleEndian.Uint32(prefix[14:18])
+		bpp := binary.LittleEndian.Uint16(prefix[28:30])
+		compression := binary.LittleEndian.Uint32(prefix[30:34])
+		if (bpp == 16 || bpp == 32 && compression == 3) && (header == 40 || header == 52 || header == 56 || header == 108 || header == 124) {
+			size := int(header) + 14
+			if header == 40 && compression == 3 {
+				size += 12
+			}
+			data := make([]byte, size)
+			if _, err := io.ReadFull(buffer, data); err != nil {
+				return image.Config{}, "bmp", err
+			}
+			config, err := decodeBMPConfig(data)
+			return config, "bmp", err
+		}
+	}
+	return image.DecodeConfig(buffer)
+}
+
+// sample 将位域采样值映射到八位通道，缺省透明度为不透明
+// 入参: value 编码像素
+// 返回: uint8 通道值
+func (m bmpColorMask) sample(value uint32) uint8 {
+	if m.mask == 0 {
+		return 255
+	}
+	return uint8(uint64((value&m.mask)>>m.shift) * 255 / uint64(m.Max))
+}
+
+// BMPColorMasks 读取BMP真彩色通道布局，校验位域连续性、重叠及像素范围
+// 入参: data 已校验头部的BMP数据, offset 像素偏移, bpp 像素位数, compression 编码方式
+// 返回: [4]bmpColorMask 红绿蓝和透明度通道, error 格式错误
+func BMPColorMasks(data []byte, offset int, bpp uint16, compression uint32) ([4]bmpColorMask, error) {
+	var result [4]bmpColorMask
+	if bpp != 16 && bpp != 24 && bpp != 32 {
+		return result, fmt.Errorf("unsupported bmp depth")
+	}
+	masks := [4]uint32{0xff0000, 0xff00, 0xff}
+	if bpp == 16 {
+		masks = [4]uint32{0x7c00, 0x3e0, 0x1f}
+	}
+	switch compression {
+	case 0:
+	case 3:
+		if bpp == 24 {
+			return result, fmt.Errorf("invalid bmp bitfield depth")
+		}
+		header := binary.LittleEndian.Uint32(data[14:18])
+		if offset < 66 || len(data) < 66 || header != 40 && header < 52 {
+			return result, fmt.Errorf("truncated bmp color masks")
+		}
+		for i := range 3 {
+			masks[i] = binary.LittleEndian.Uint32(data[54+i*4:])
+		}
+		if header >= 56 {
+			masks[3] = binary.LittleEndian.Uint32(data[66:70])
+		}
+	default:
+		return result, fmt.Errorf("unsupported bmp compression")
+	}
+	var used uint32
+	for i, mask := range masks {
+		if mask == 0 {
+			if i < 3 {
+				return result, fmt.Errorf("empty bmp color mask")
+			}
+			continue
+		}
+		shift := uint(bits.TrailingZeros32(mask))
+		maximum := mask >> shift
+		if mask&used != 0 || maximum&(maximum+1) != 0 || uint64(mask)>>bpp != 0 {
+			return result, fmt.Errorf("invalid bmp color mask")
+		}
+		result[i] = bmpColorMask{mask: mask, shift: shift, Max: maximum}
+		used |= mask
+	}
+	return result, nil
+}

internal/base/image/color.go

@@ -0,0 +1,340 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package image
+
+import (
+	"bytes"
+	"compress/zlib"
+	"context"
+	"encoding/binary"
+	"fmt"
+	"hash/crc32"
+	"image"
+	"image/color"
+	"io"
+	"math"
+
+	"github.com/xiaoqidun/pdfgo"
+)
+
+// colorImage 保留源采样及独立的十六位显示像素
+type colorImage struct {
+	*image.NRGBA64
+	source image.Image
+}
+
+// pngColor 保存PNG校准空间及缺省sRGB传递函数
+type pngColor struct {
+	space      *pdfgo.ColorSpace
+	linearSRGB bool
+}
+
+// pngColorProfile 读取PNG颜色元数据，ICC优先于sRGB及独立校准参数
+// 入参: ctx 取消上下文, data 原始编码
+// 返回: []byte ICC编码, *pngColor 校准参数, error 格式或配置错误
+func pngColorProfile(ctx context.Context, data []byte) ([]byte, *pngColor, error) {
+	const profileLimit = 16 << 20
+	chunks := make(map[string][]byte)
+	for at := 8; at < len(data); {
+		if err := ctx.Err(); err != nil {
+			return nil, nil, err
+		}
+		if len(data)-at < 8 {
+			return nil, nil, fmt.Errorf("truncated PNG chunk")
+		}
+		kind := string(data[at+4 : at+8])
+		if kind == "IDAT" || kind == "PLTE" {
+			break
+		}
+		if len(data)-at < 12 {
+			return nil, nil, fmt.Errorf("truncated PNG chunk")
+		}
+		size := uint64(binary.BigEndian.Uint32(data[at:]))
+		if size > uint64(len(data)-at-12) {
+			return nil, nil, fmt.Errorf("invalid PNG chunk length")
+		}
+		end := at + 8 + int(size)
+		switch kind {
+		case "iCCP", "sRGB", "gAMA", "cHRM":
+			if _, ok := chunks[kind]; ok {
+				return nil, nil, fmt.Errorf("invalid PNG %s chunk order", kind)
+			}
+			if crc32.ChecksumIEEE(data[at+4:end]) != binary.BigEndian.Uint32(data[end:]) {
+				return nil, nil, fmt.Errorf("invalid PNG %s checksum", kind)
+			}
+			chunks[kind] = data[at+8 : end]
+		}
+		at = end + 4
+		if kind == "IEND" {
+			break
+		}
+	}
+	if chunk, ok := chunks["iCCP"]; ok {
+		name := bytes.IndexByte(chunk, 0)
+		if name < 1 || name > 79 || len(chunk) < name+3 || chunk[name+1] != 0 {
+			return nil, nil, fmt.Errorf("invalid PNG ICC header")
+		}
+		for i, c := range chunk[:name] {
+			if c < 32 || c > 126 && c < 161 || c == 32 && (i == 0 || i == name-1 || chunk[i-1] == 32) {
+				return nil, nil, fmt.Errorf("invalid PNG ICC name")
+			}
+		}
+		input := bytes.NewReader(chunk[name+2:])
+		reader, err := zlib.NewReader(input)
+		if err != nil {
+			return nil, nil, err
+		}
+		profile, err := io.ReadAll(io.LimitReader(contextInput{ReadCloser: reader, ctx: ctx}, profileLimit+1))
+		closeErr := reader.Close()
+		if err != nil {
+			return nil, nil, err
+		}
+		if closeErr != nil {
+			return nil, nil, closeErr
+		}
+		if len(profile) > profileLimit {
+			return nil, nil, fmt.Errorf("PNG ICC profile exceeds size limit")
+		}
+		if input.Len() != 0 {
+			return nil, nil, fmt.Errorf("trailing PNG ICC data")
+		}
+		kind := "RGB "
+		if len(data) > 25 && (data[25] == 0 || data[25] == 4) {
+			kind = "GRAY"
+		}
+		if len(profile) < 132 || string(profile[16:20]) != kind {
+			return nil, nil, fmt.Errorf("ICC source model does not match PNG color space %q", kind)
+		}
+		return profile, nil, nil
+	}
+	if chunk, ok := chunks["sRGB"]; ok {
+		if len(chunk) != 1 || chunk[0] > 3 {
+			return nil, nil, fmt.Errorf("invalid PNG sRGB intent")
+		}
+		return nil, nil, nil
+	}
+	if len(chunks) == 0 {
+		return nil, nil, nil
+	}
+	coordinates := [8]float64{0.3127, 0.3290, 0.6400, 0.3300, 0.3000, 0.6000, 0.1500, 0.0600}
+	if chunk, ok := chunks["cHRM"]; ok {
+		if len(chunk) != 32 {
+			return nil, nil, fmt.Errorf("invalid PNG chromaticities")
+		}
+		for i := range coordinates {
+			coordinates[i] = float64(binary.BigEndian.Uint32(chunk[i*4:])) / 100000
+		}
+	}
+	var xyz [4][3]float64
+	for i := range xyz {
+		x, y := coordinates[2*i], coordinates[2*i+1]
+		if y <= 0 || x < 0 || x+y > 1 {
+			return nil, nil, fmt.Errorf("invalid PNG chromaticities")
+		}
+		xyz[i] = [3]float64{x / y, 1, (1 - x - y) / y}
+	}
+	white := xyz[0]
+	det := func(a, b, c [3]float64) float64 {
+		return a[0]*(b[1]*c[2]-b[2]*c[1]) - b[0]*(a[1]*c[2]-a[2]*c[1]) + c[0]*(a[1]*b[2]-a[2]*b[1])
+	}
+	d := det(xyz[1], xyz[2], xyz[3])
+	if math.Abs(d) < 1e-12 {
+		return nil, nil, fmt.Errorf("degenerate PNG chromaticities")
+	}
+	scale := [3]float64{det(white, xyz[2], xyz[3]) / d, det(xyz[1], white, xyz[3]) / d, det(xyz[1], xyz[2], white) / d}
+	var matrix [9]float64
+	for i := range 3 {
+		for j := range 3 {
+			matrix[3*i+j] = xyz[i+1][j] * scale[i]
+		}
+	}
+	gamma := [3]float64{1, 1, 1}
+	linear := true
+	if chunk, ok := chunks["gAMA"]; ok {
+		if len(chunk) != 4 || binary.BigEndian.Uint32(chunk) == 0 {
+			return nil, nil, fmt.Errorf("invalid PNG gamma")
+		}
+		g := 100000 / float64(binary.BigEndian.Uint32(chunk))
+		gamma = [3]float64{g, g, g}
+		linear = false
+	}
+	space, err := pdfgo.NewCalRGBColorSpace(white, [3]float64{}, gamma, matrix)
+	if err != nil {
+		return nil, nil, err
+	}
+	return nil, &pngColor{space: space, linearSRGB: linear}, nil
+}
+
+// jpegColorProfile 读取JPEG分段ICC配置，拒绝缺段、重复及模型不匹配
+// 入参: ctx 取消上下文, data JPEG编码, model 源颜色模型
+// 返回: []byte 独立配置编码，未声明时为nil, error 配置或取消错误
+func jpegColorProfile(ctx context.Context, data []byte, model color.Model) ([]byte, error) {
+	var parts [255][]byte
+	count, found, total := 0, 0, 0
+	for at := 2; at < len(data); {
+		if err := ctx.Err(); err != nil {
+			return nil, err
+		}
+		if data[at] != 0xff {
+			return nil, fmt.Errorf("invalid JPEG marker")
+		}
+		for at < len(data) && data[at] == 0xff {
+			at++
+		}
+		if at == len(data) {
+			return nil, fmt.Errorf("truncated JPEG marker")
+		}
+		marker := data[at]
+		at++
+		if marker == 0xda || marker == 0xd9 {
+			break
+		}
+		if marker == 0x01 || marker >= 0xd0 && marker <= 0xd7 {
+			continue
+		}
+		if len(data)-at < 2 {
+			return nil, fmt.Errorf("truncated JPEG segment")
+		}
+		size := int(binary.BigEndian.Uint16(data[at:]))
+		if size < 2 || size > len(data)-at {
+			return nil, fmt.Errorf("invalid JPEG segment length")
+		}
+		segment := data[at+2 : at+size]
+		at += size
+		if marker != 0xe2 || !bytes.HasPrefix(segment, []byte("ICC_PROFILE\x00")) {
+			continue
+		}
+		if len(segment) <= 14 {
+			return nil, fmt.Errorf("truncated JPEG color profile")
+		}
+		index, n := int(segment[12]), int(segment[13])
+		if index == 0 || index > n || count != 0 && count != n || parts[index-1] != nil {
+			return nil, fmt.Errorf("invalid JPEG color profile sequence")
+		}
+		count, found = n, found+1
+		parts[index-1] = segment[14:]
+		total += len(segment) - 14
+	}
+	if found == 0 {
+		return nil, nil
+	}
+	if found != count {
+		return nil, fmt.Errorf("incomplete JPEG color profile")
+	}
+	profile := make([]byte, 0, total)
+	for _, part := range parts[:count] {
+		profile = append(profile, part...)
+	}
+	kind := "RGB "
+	if model == color.CMYKModel {
+		kind = "CMYK"
+	} else if model == color.GrayModel {
+		kind = "GRAY"
+	}
+	if len(profile) < 132 || string(profile[16:20]) != kind {
+		return nil, fmt.Errorf("ICC source model does not match JPEG color space %q", kind)
+	}
+	return profile, nil
+}
+
+// jpegDisplayImage 统一JPEG显示变换，保留源分量并精确复用相邻同色的ICC结果
+// 入参: ctx 取消上下文, source 源像素, profile 颜色配置，可为nil
+// 返回: image.Image 显示像素, error 变换或取消错误
+func jpegDisplayImage(ctx context.Context, source image.Image, profile *pdfgo.ColorSpace) (image.Image, error) {
+	cmyk, ok := source.(*image.CMYK)
+	if !ok {
+		if profile != nil {
+			return applyTIFFColorProfile(ctx, source, profile)
+		}
+		return source, nil
+	}
+	bounds := cmyk.Bounds()
+	if bounds.Dx() <= 0 || bounds.Dy() <= 0 || bounds.Dx() > math.MaxInt/8/bounds.Dy() {
+		return nil, fmt.Errorf("JPEG color image dimensions exceed capacity")
+	}
+	pixels := image.NewNRGBA64(bounds)
+	var intent pdfgo.Name
+	if profile != nil {
+		intent = profile.DefaultIntent()
+	}
+	var previous color.CMYK
+	var previousPixel color.NRGBA64
+	for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
+		for x := bounds.Min.X; x < bounds.Max.X; x++ {
+			if (x-bounds.Min.X)&255 == 0 {
+				if err := ctx.Err(); err != nil {
+					return nil, err
+				}
+			}
+			ink := cmyk.CMYKAt(x, y)
+			if profile == nil {
+				white := 255 - int(ink.K)
+				pixels.SetNRGBA64(x, y, color.NRGBA64{
+					R: uint16(max(0, white-int(ink.C))) * 257,
+					G: uint16(max(0, white-int(ink.M))) * 257,
+					B: uint16(max(0, white-int(ink.Y))) * 257,
+					A: 65535,
+				})
+				continue
+			}
+			if previousPixel.A != 0 && ink == previous {
+				pixels.SetNRGBA64(x, y, previousPixel)
+				continue
+			}
+			values := [4]float64{float64(ink.C) / 255, float64(ink.M) / 255, float64(ink.Y) / 255, float64(ink.K) / 255}
+			rgb, err := profile.SRGB(values[:], intent)
+			if err != nil {
+				return nil, err
+			}
+			previous = ink
+			previousPixel = color.NRGBA64{R: colorWord(rgb[0]), G: colorWord(rgb[1]), B: colorWord(rgb[2]), A: 65535}
+			pixels.SetNRGBA64(x, y, previousPixel)
+		}
+	}
+	return &colorImage{NRGBA64: pixels, source: source}, nil
+}
+
+// colorWord 将归一化颜色舍入为十六位分量
+// 入参: value 颜色分量
+// 返回: uint16 十六位分量
+func colorWord(value float64) uint16 {
+	return uint16(math.Round(max(0, min(1, value)) * 65535))
+}
+
+// cmykGrayAt 从原始四色采样计算蒙版灰度，不应用显示配置
+// 入参: x 横坐标, y 纵坐标
+// 返回: color.Gray 蒙版灰度
+func (p *planarTIFFImage) cmykGrayAt(x, y int) color.Gray {
+	if !image.Pt(x, y).In(p.bounds) {
+		return color.Gray{}
+	}
+	ink := p.inksAt(x, y)
+	maximum := uint32(65535)
+	if p.alpha == 1 {
+		maximum = uint32(ink[4])
+		if maximum == 0 {
+			return color.Gray{}
+		}
+	}
+	black := maximum - min(uint32(ink[3]), maximum)
+	var rgb [3]uint32
+	for i := range rgb {
+		rgb[i] = (maximum - min(uint32(ink[i]), maximum)) * black / maximum
+		if p.alpha != 1 {
+			rgb[i] = rgb[i] * uint32(ink[4]) / 65535
+		}
+	}
+	return color.Gray{Y: uint8((19595*rgb[0] + 38470*rgb[1] + 7471*rgb[2] + 1<<15) >> 24)}
+}

internal/base/image/encoded.go

@@ -0,0 +1,211 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package image
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"image"
+	"image/color"
+	_ "image/jpeg"
+	_ "image/png"
+	"io"
+	"sync"
+	"sync/atomic"
+
+	"github.com/xiaoqidun/pdfgo"
+)
+
+// EncodedImage 保留PNG或JPEG原始编码，首次读取像素时解码
+// Bytes返回只读数据，Image返回共享只读像素，解码错误由Image返回
+type EncodedImage struct {
+	data     []byte
+	format   string
+	config   image.Config
+	profile  []byte
+	pngColor *pngColor
+	result   atomic.Pointer[encodedImageResult]
+	mu       sync.Mutex
+	pending  chan struct{}
+}
+
+// encodedImageResult 保存已完成的像素解码结果，不保存取消或超时错误
+type encodedImageResult struct {
+	image image.Image
+	err   error
+}
+
+// NewEncodedImage 校验PNG或JPEG头信息后复制输入，不解码像素
+// 入参: data 原始编码
+// 返回: *EncodedImage 惰性图片, error 头信息或格式错误
+func NewEncodedImage(data []byte) (*EncodedImage, error) {
+	img, err := newEncodedImage(data)
+	if err != nil {
+		return nil, err
+	}
+	img.data = bytes.Clone(data)
+	return img, nil
+}
+
+// Bytes 返回只读原始编码，调用方不得修改
+// 返回: []byte 原始编码
+func (img *EncodedImage) Bytes() []byte { return img.data }
+
+// MIME 返回图片媒体类型
+// 返回: string 媒体类型
+func (img *EncodedImage) MIME() string { return "image/" + img.format }
+
+// ColorModel 返回显示像素的颜色模型，不解码像素
+// 返回: color.Model 颜色模型
+func (img *EncodedImage) ColorModel() color.Model {
+	if img.profile != nil || img.pngColor != nil || img.config.ColorModel == color.CMYKModel {
+		return color.NRGBA64Model
+	}
+	return img.config.ColorModel
+}
+
+// Bounds 返回图片范围，不解码像素
+// 返回: image.Rectangle 图片范围
+func (img *EncodedImage) Bounds() image.Rectangle {
+	return image.Rect(0, 0, img.config.Width, img.config.Height)
+}
+
+// Image 首次解码图片并缓存结果或错误，支持并发读取
+// 返回: image.Image 只读像素, error 解码错误
+func (img *EncodedImage) Image() (image.Image, error) {
+	if result := img.result.Load(); result != nil {
+		return result.image, result.err
+	}
+	return img.ImageContext(context.Background())
+}
+
+// ImageContext 解码并共享只读像素，取消或超时后可重试，nil使用后台上下文
+// 并发调用等待正在进行的解码，等待方取消不影响其他调用
+// 入参: ctx 取消上下文
+// 返回: image.Image 只读像素, error 解码或取消错误
+func (img *EncodedImage) ImageContext(ctx context.Context) (image.Image, error) {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	for {
+		if err := ctx.Err(); err != nil {
+			return nil, err
+		}
+		if result := img.result.Load(); result != nil {
+			return result.image, result.err
+		}
+		img.mu.Lock()
+		if img.result.Load() != nil {
+			img.mu.Unlock()
+			continue
+		}
+		pending := img.pending
+		if pending == nil {
+			pending = make(chan struct{})
+			img.pending = pending
+			img.mu.Unlock()
+			return img.decodeContext(ctx, pending)
+		}
+		img.mu.Unlock()
+		select {
+		case <-ctx.Done():
+			return nil, ctx.Err()
+		case <-pending:
+		}
+	}
+}
+
+// decodeContext 执行本次解码，退出时唤醒等待方，只缓存完整结果及稳定错误
+// 入参: ctx 取消上下文, pending 本次解码的完成通知
+// 返回: image.Image 只读像素, error 解码或取消错误
+func (img *EncodedImage) decodeContext(ctx context.Context, pending chan struct{}) (image.Image, error) {
+	defer func() {
+		img.mu.Lock()
+		img.pending = nil
+		close(pending)
+		img.mu.Unlock()
+	}()
+	pixels, _, err := image.Decode(contextInput{ReadCloser: io.NopCloser(bytes.NewReader(img.data)), ctx: ctx})
+	if err == nil && (img.format == "jpeg" || img.profile != nil) {
+		var profile *pdfgo.ColorSpace
+		if img.profile != nil {
+			profile, err = pdfgo.NewICCColorSpace(img.profile)
+		}
+		if err == nil {
+			pixels, err = jpegDisplayImage(ctx, pixels, profile)
+		}
+	}
+	if err == nil && img.pngColor != nil {
+		pixels, err = applyImageColorProfile(ctx, pixels, img.pngColor.space, img.pngColor.linearSRGB)
+	}
+	if cancelErr := ctx.Err(); cancelErr != nil {
+		return nil, cancelErr
+	}
+	if errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
+		return nil, err
+	}
+	img.result.Store(&encodedImageResult{image: pixels, err: err})
+	return pixels, err
+}
+
+// At 返回像素颜色，解码失败时返回透明色，绘制前应通过Image检查错误
+// 入参: x 横坐标, y 纵坐标
+// 返回: color.Color 像素颜色
+func (img *EncodedImage) At(x, y int) color.Color {
+	decoded, err := img.Image()
+	if err != nil {
+		return color.Transparent
+	}
+	return decoded.At(x, y)
+}
+
+// newEncodedImage 接管编码数据并读取头信息
+// 入参: data 原始编码
+// 返回: *EncodedImage 惰性图片, error 头信息或格式错误
+func newEncodedImage(data []byte) (*EncodedImage, error) {
+	return newEncodedImageContext(context.Background(), data)
+}
+
+// newEncodedImageContext 读取PNG或JPEG头信息，元数据扫描期间响应取消，不复制输入或解码像素
+// 入参: ctx 取消上下文, data 只读图片编码
+// 返回: *EncodedImage 惰性图片, error 头信息、格式或取消错误
+func newEncodedImageContext(ctx context.Context, data []byte) (*EncodedImage, error) {
+	config, format, err := image.DecodeConfig(contextInput{ReadCloser: io.NopCloser(bytes.NewReader(data)), ctx: ctx})
+	if cancelErr := ctx.Err(); cancelErr != nil {
+		return nil, cancelErr
+	}
+	if err != nil {
+		return nil, err
+	}
+	if format != "jpeg" && format != "png" {
+		return nil, fmt.Errorf("unsupported encoded image %q", format)
+	}
+	img := &EncodedImage{data: data, format: format, config: config}
+	if format == "jpeg" {
+		img.profile, err = jpegColorProfile(ctx, data, config.ColorModel)
+		if err != nil {
+			return nil, err
+		}
+	}
+	if format == "png" {
+		img.profile, img.pngColor, err = pngColorProfile(ctx, data)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return img, nil
+}

internal/base/image/format.go

@@ -0,0 +1,31 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package image
+
+// NormalizeFormat 标准化印章媒体类型
+// 入参: s 原始媒体类型
+// 返回: string 标准媒体类型
+func NormalizeFormat(s string) string {
+	switch s {
+	case "jpg":
+		return "jpeg"
+	case "bmp":
+		return "bmp"
+	case "jb2", "gbig2":
+		return "jbig2"
+	default:
+		return s
+	}
+}

internal/base/image/image.go

@@ -0,0 +1,827 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package image
+
+import (
+	"bytes"
+	"context"
+	"encoding/binary"
+	"fmt"
+	"image"
+	"image/color"
+	_ "image/gif"
+	"io"
+
+	_ "github.com/xiaoqidun/j2kgo"
+	_ "github.com/xiaoqidun/jbig2"
+	_ "golang.org/x/image/bmp"
+	"golang.org/x/image/tiff"
+)
+
+// transparentEdgeImage 共享只读像素并按需计算透明边缘和采样边距
+type transparentEdgeImage struct {
+	source image.Image
+	rect   image.Rectangle
+}
+
+// transparentEdgeImage64 按需补齐十六位像素边缘，保留原始只读图像
+type transparentEdgeImage64 struct {
+	source image.Image
+	rect   image.Rectangle
+}
+
+// Bounds 返回含采样边距的图像边界
+// 返回: image.Rectangle 图像边界
+func (s *transparentEdgeImage) Bounds() image.Rectangle { return s.rect }
+
+// ColorModel 返回非预乘颜色模型
+// 返回: color.Model 颜色模型
+func (s *transparentEdgeImage) ColorModel() color.Model { return color.NRGBAModel }
+
+// NRGBAAt 读取原始像素或按邻域补齐透明边缘，边界外透明
+// 入参: x 横向坐标, y 纵向坐标
+// 返回: color.NRGBA 非预乘颜色
+func (s *transparentEdgeImage) NRGBAAt(x, y int) color.NRGBA {
+	if !image.Pt(x, y).In(s.rect) {
+		return color.NRGBA{}
+	}
+	b := s.source.Bounds()
+	sx, sy := b.Min.X+min(max(x-1, 0), b.Dx()-1), b.Min.Y+min(max(y-1, 0), b.Dy()-1)
+	c := NRGBAAt(s.source, sx, sy)
+	if c.A == 0 {
+		if edge, ok := transparentEdgeColor(s.source, sx, sy); ok {
+			c = edge
+		}
+	}
+	if x == 0 || y == 0 || x == s.rect.Max.X-1 || y == s.rect.Max.Y-1 {
+		c = transparentPaddingColor(c)
+	}
+	return c
+}
+
+// At 返回非预乘像素颜色
+// 入参: x 横向坐标, y 纵向坐标
+// 返回: color.Color 像素颜色
+func (s *transparentEdgeImage) At(x, y int) color.Color { return s.NRGBAAt(x, y) }
+
+// RGBA64At 返回预乘十六位像素，供采样器无装箱读取
+// 入参: x 横向坐标, y 纵向坐标
+// 返回: color.RGBA64 预乘颜色
+func (s *transparentEdgeImage) RGBA64At(x, y int) color.RGBA64 {
+	r, g, b, a := s.NRGBAAt(x, y).RGBA()
+	return color.RGBA64{R: uint16(r), G: uint16(g), B: uint16(b), A: uint16(a)}
+}
+
+// Bounds 返回含采样边距的图像边界
+// 返回: image.Rectangle 图像边界
+func (s *transparentEdgeImage64) Bounds() image.Rectangle { return s.rect }
+
+// ColorModel 返回十六位非预乘颜色模型
+// 返回: color.Model 颜色模型
+func (s *transparentEdgeImage64) ColorModel() color.Model { return color.NRGBA64Model }
+
+// NRGBA64At 读取十六位原始颜色，透明邻域使用最小非零透明度保留边缘颜色
+// 入参: x 横向坐标, y 纵向坐标
+// 返回: color.NRGBA64 非预乘颜色
+func (s *transparentEdgeImage64) NRGBA64At(x, y int) color.NRGBA64 {
+	if !image.Pt(x, y).In(s.rect) {
+		return color.NRGBA64{}
+	}
+	b := s.source.Bounds()
+	sx, sy := b.Min.X+min(max(x-1, 0), b.Dx()-1), b.Min.Y+min(max(y-1, 0), b.Dy()-1)
+	c := NRGBA64At(s.source, sx, sy)
+	if c.A == 0 {
+		var best color.NRGBA64
+		for ny := max(sy-1, b.Min.Y); ny < min(sy+2, b.Max.Y); ny++ {
+			for nx := max(sx-1, b.Min.X); nx < min(sx+2, b.Max.X); nx++ {
+				v := NRGBA64At(s.source, nx, ny)
+				if v.A > best.A {
+					best = v
+				}
+			}
+		}
+		if best.A != 0 {
+			best.A = 1
+			c = best
+		}
+	}
+	if x == 0 || y == 0 || x == s.rect.Max.X-1 || y == s.rect.Max.Y-1 {
+		c.A = 1
+	}
+	return c
+}
+
+// At 返回非预乘十六位像素颜色
+// 入参: x 横向坐标, y 纵向坐标
+// 返回: color.Color 像素颜色
+func (s *transparentEdgeImage64) At(x, y int) color.Color { return s.NRGBA64At(x, y) }
+
+// RGBA64At 返回保留原采样精度的预乘颜色
+// 入参: x 横向坐标, y 纵向坐标
+// 返回: color.RGBA64 预乘颜色
+func (s *transparentEdgeImage64) RGBA64At(x, y int) color.RGBA64 {
+	r, g, b, a := s.NRGBA64At(x, y).RGBA()
+	return color.RGBA64{R: uint16(r), G: uint16(g), B: uint16(b), A: uint16(a)}
+}
+
+// Decode 解码图片数据
+// 入参: data 图片数据
+// 返回: image.Image 图片对象, string 图片格式, error 错误信息
+func Decode(data []byte) (image.Image, string, error) {
+	return DecodeContext(context.Background(), data)
+}
+
+// DecodeContext 解码图片并传递取消状态，PNG和JPEG仍保留惰性像素解码
+// 入参: ctx 取消上下文, data 只读图片编码
+// 返回: image.Image 图片对象, string 图片格式, error 解码或取消错误
+func DecodeContext(ctx context.Context, data []byte) (img image.Image, format string, err error) {
+	if err := ctx.Err(); err != nil {
+		return nil, "", err
+	}
+	defer func() {
+		if cancelErr := ctx.Err(); cancelErr != nil {
+			img, err = nil, cancelErr
+		}
+	}()
+	if IsJPEG(data) || IsPNG(data) {
+		img, err := newEncodedImageContext(ctx, data)
+		if err != nil {
+			return nil, "", err
+		}
+		return img, img.format, nil
+	}
+	if IsTIFF(data) {
+		layout, err := ReadTIFFLayoutContext(ctx, bytes.NewReader(data))
+		if err != nil {
+			return nil, "tiff", err
+		}
+		img, err := DecodeTIFF(ctx, data, layout)
+		return img, "tiff", err
+	}
+	img, format, err = image.Decode(contextInput{ReadCloser: io.NopCloser(bytes.NewReader(data)), ctx: ctx})
+	if err == nil {
+		return img, NormalizeFormat(format), nil
+	}
+	if ctx.Err() != nil {
+		return nil, "", ctx.Err()
+	}
+	if img, err := DecodeBMPContext(ctx, data); err == nil {
+		return img, "bmp", nil
+	}
+	return nil, "", err
+}
+
+// DecodePixelsContext 完整解码图片，确保像素可读取并传递取消状态
+// 入参: ctx 取消上下文, data 图片编码数据
+// 返回: image.Image 解码像素, string 图片格式, error 解码或取消错误
+func DecodePixelsContext(ctx context.Context, data []byte) (image.Image, string, error) {
+	img, format, err := DecodeContext(ctx, data)
+	if err != nil {
+		return nil, format, err
+	}
+	pixels, err := PixelDataContext(ctx, img)
+	return pixels, format, err
+}
+
+// IsJPEG 判断是否为JPEG图片数据
+// 入参: data 图片数据
+// 返回: bool 是否为JPEG图片数据
+func IsJPEG(data []byte) bool {
+	return len(data) >= 2 && data[0] == 0xFF && data[1] == 0xD8
+}
+
+// IsPNG 判断是否为PNG图片数据
+// 入参: data 图片数据
+// 返回: bool 是否为PNG图片数据
+func IsPNG(data []byte) bool {
+	return bytes.HasPrefix(data, []byte("\x89PNG\r\n\x1a\n"))
+}
+
+// DecodeConfigData 解码图片尺寸
+// 入参: data 图片数据
+// 返回: image.Config 图片尺寸, string 图片格式, error 错误信息
+func DecodeConfigData(data []byte) (image.Config, string, error) {
+	return DecodeConfigDataContext(context.Background(), data)
+}
+
+// DecodeConfigDataContext 读取图片尺寸和颜色模型，传递布局解析中的取消状态
+// 入参: ctx 取消上下文, data 图片数据
+// 返回: image.Config 图片配置, string 图片格式, error 读取或取消错误
+func DecodeConfigDataContext(ctx context.Context, data []byte) (config image.Config, format string, err error) {
+	if err := ctx.Err(); err != nil {
+		return image.Config{}, "", err
+	}
+	defer func() {
+		if cancelErr := ctx.Err(); cancelErr != nil {
+			config, err = image.Config{}, cancelErr
+		}
+	}()
+	if IsTIFF(data) {
+		layout, err := ReadTIFFLayoutContext(ctx, bytes.NewReader(data))
+		if err != nil {
+			return image.Config{}, "tiff", err
+		}
+		profile, err := readTIFFColorProfile(ctx, data, layout)
+		if err != nil {
+			return image.Config{}, "tiff", err
+		}
+		var cfg image.Config
+		if layout.needsSampleView() {
+			img, _, err := tiffPlaneDirectories(ctx, data, layout)
+			if err != nil {
+				return image.Config{}, "tiff", err
+			}
+			cfg.ColorModel = img.ColorModel()
+		} else {
+			input := newTIFFDirectoryInput(data, layout.Offset)
+			input.ctx = ctx
+			cfg, err = tiff.DecodeConfig(input)
+			if err != nil {
+				return image.Config{}, "tiff", err
+			}
+		}
+		if profile != nil || layout.Transparency != nil {
+			cfg.ColorModel = color.NRGBA64Model
+		}
+		if layout.Transparency != nil {
+			if _, err := readTIFFColorProfile(ctx, data, *layout.Transparency); err != nil {
+				return image.Config{}, "tiff", err
+			}
+			if _, _, err := tiffPlaneDirectories(ctx, data, *layout.Transparency); err != nil {
+				return image.Config{}, "tiff", err
+			}
+		}
+		size := layout.DisplaySize()
+		cfg.Width, cfg.Height = size.X, size.Y
+		return cfg, "tiff", nil
+	}
+	cfg, format, err := image.DecodeConfig(contextInput{ReadCloser: io.NopCloser(bytes.NewReader(data)), ctx: ctx})
+	if err == nil {
+		return cfg, NormalizeFormat(format), nil
+	}
+	if cfg, err := decodeBMPConfig(data); err == nil {
+		return cfg, "bmp", nil
+	}
+	return image.Config{}, "", err
+}
+
+// decodeBMPConfig 解码BMP尺寸
+// 入参: data 图片数据
+// 返回: image.Config 图片尺寸, error 错误信息
+func decodeBMPConfig(data []byte) (image.Config, error) {
+	offset, width, height, bpp, compression, err := ParseBMPHeader(data)
+	if err != nil {
+		return image.Config{}, err
+	}
+	if offset <= 0 || width <= 0 || height == 0 {
+		return image.Config{}, fmt.Errorf("unsupported bmp")
+	}
+	if _, err := BMPColorMasks(data, offset, bpp, compression); err != nil {
+		return image.Config{}, err
+	}
+	if height < 0 {
+		height = -height
+	}
+	return image.Config{ColorModel: color.NRGBAModel, Width: width, Height: height}, nil
+}
+
+// decodeBMPImage 解码BMP图片
+// 入参: data 图片数据
+// 返回: image.Image 图片对象, error 错误信息
+func decodeBMPImage(data []byte) (image.Image, error) {
+	return DecodeBMPContext(context.Background(), data)
+}
+
+// DecodeBMPContext 解码BMP真彩色像素，逐行检查取消
+// 入参: ctx 取消上下文, data 图片数据
+// 返回: image.Image 图片对象, error 格式或取消错误
+func DecodeBMPContext(ctx context.Context, data []byte) (image.Image, error) {
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	offset, width, height, bpp, compression, err := ParseBMPHeader(data)
+	if err != nil {
+		return nil, err
+	}
+	if offset > len(data) {
+		return nil, fmt.Errorf("invalid bmp pixel offset")
+	}
+	masks, err := BMPColorMasks(data, offset, bpp, compression)
+	if err != nil {
+		return nil, err
+	}
+	topDown := height < 0
+	if topDown {
+		height = -height
+	}
+	if width <= 0 || height <= 0 {
+		return nil, fmt.Errorf("invalid bmp size")
+	}
+	stride := ((int64(width)*int64(bpp) + 31) / 32) * 4
+	if stride > int64(len(data)-offset)/int64(height) {
+		return nil, fmt.Errorf("truncated bmp")
+	}
+	if width > int(^uint(0)>>1)/4/height {
+		return nil, fmt.Errorf("bmp dimensions exceed image capacity")
+	}
+	rowStride := int(stride)
+	img := image.NewNRGBA(image.Rect(0, 0, width, height))
+	for y := 0; y < height; y++ {
+		if err := ctx.Err(); err != nil {
+			return nil, err
+		}
+		srcY := y
+		if !topDown {
+			srcY = height - 1 - y
+		}
+		row := data[offset+srcY*rowStride:]
+		for x := 0; x < width; x++ {
+			switch bpp {
+			case 16, 32:
+				var value uint32
+				if bpp == 16 {
+					value = uint32(binary.LittleEndian.Uint16(row[x*2:]))
+				} else {
+					value = binary.LittleEndian.Uint32(row[x*4:])
+				}
+				p := y*img.Stride + x*4
+				for i, mask := range masks {
+					img.Pix[p+i] = mask.sample(value)
+				}
+			case 24:
+				p := x * 3
+				img.SetNRGBA(x, y, color.NRGBA{R: row[p+2], G: row[p+1], B: row[p], A: 255})
+			}
+		}
+	}
+	return img, nil
+}
+
+// ParseBMPHeader 解析BMP文件头
+// 入参: data 图片数据
+// 返回: int 像素偏移, int 宽度, int 高度, uint16 位数, uint32 压缩方式, error 错误信息
+func ParseBMPHeader(data []byte) (int, int, int, uint16, uint32, error) {
+	if len(data) < 54 || string(data[:2]) != "BM" {
+		return 0, 0, 0, 0, 0, fmt.Errorf("not bmp")
+	}
+	offset := int(binary.LittleEndian.Uint32(data[10:14]))
+	dibSize := binary.LittleEndian.Uint32(data[14:18])
+	if dibSize < 40 {
+		return 0, 0, 0, 0, 0, fmt.Errorf("unsupported bmp")
+	}
+	if uint64(dibSize)+14 > uint64(len(data)) || offset < 0 || uint64(offset) < uint64(dibSize)+14 {
+		return 0, 0, 0, 0, 0, fmt.Errorf("invalid bmp pixel offset")
+	}
+	width := int(int32(binary.LittleEndian.Uint32(data[18:22])))
+	height := int(int32(binary.LittleEndian.Uint32(data[22:26])))
+	planes := binary.LittleEndian.Uint16(data[26:28])
+	bpp := binary.LittleEndian.Uint16(data[28:30])
+	compression := binary.LittleEndian.Uint32(data[30:34])
+	if planes != 1 || width <= 0 || height == 0 || int64(height) == -int64(^uint(0)>>1)-1 {
+		return 0, 0, 0, 0, 0, fmt.Errorf("invalid bmp")
+	}
+	return offset, width, height, bpp, compression, nil
+}
+
+// PixelSource 获取图片像素源
+// 入参: img 图片对象
+// 返回: image.Image 图片像素源
+func PixelSource(img image.Image) image.Image {
+	if decoded, err := PixelData(img); err == nil {
+		return decoded
+	}
+	return img
+}
+
+// PixelData 获取像素并保留惰性解码错误，供绘制和像素处理入口校验
+// 入参: img 图片对象
+// 返回: image.Image 解码像素, error 解码错误
+func PixelData(img image.Image) (image.Image, error) {
+	if src, ok := img.(interface{ Image() (image.Image, error) }); ok {
+		return src.Image()
+	}
+	return img, nil
+}
+
+// PixelDataContext 获取像素并传递取消状态，兼容不接收上下文的图像实现
+// 入参: ctx 取消上下文，nil使用后台上下文, img 图片对象
+// 返回: image.Image 解码像素, error 解码或取消错误
+func PixelDataContext(ctx context.Context, img image.Image) (image.Image, error) {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	if src, ok := img.(interface {
+		ImageContext(context.Context) (image.Image, error)
+	}); ok {
+		return src.ImageContext(ctx)
+	}
+	pixels, err := PixelData(img)
+	if cancelErr := ctx.Err(); cancelErr != nil {
+		return nil, cancelErr
+	}
+	return pixels, err
+}
+
+// GrayAt 获取图片灰度像素
+// 入参: img 图片对象, x X坐标, y Y坐标
+// 返回: color.Gray 灰度像素
+func GrayAt(img image.Image, x, y int) color.Gray {
+	switch src := img.(type) {
+	case *EncodedImage:
+		pixels, err := src.Image()
+		if err != nil {
+			return color.Gray{}
+		}
+		return GrayAt(pixels, x, y)
+	case *colorImage:
+		return GrayAt(src.source, x, y)
+	case *maskedTIFFImage:
+		if src.alphaAt(x, y) == 0 {
+			return color.Gray{}
+		}
+		point := src.samplePoint(src.source.Bounds(), x, y)
+		return GrayAt(src.source, point.X, point.Y)
+	case *transparentEdgeImage:
+		if x <= src.rect.Min.X || y <= src.rect.Min.Y || x >= src.rect.Max.X-1 || y >= src.rect.Max.Y-1 {
+			return color.Gray{}
+		}
+		bounds := src.source.Bounds()
+		return GrayAt(src.source, bounds.Min.X+x-1, bounds.Min.Y+y-1)
+	case *transparentEdgeImage64:
+		if x <= src.rect.Min.X || y <= src.rect.Min.Y || x >= src.rect.Max.X-1 || y >= src.rect.Max.Y-1 {
+			return color.Gray{}
+		}
+		bounds := src.source.Bounds()
+		return GrayAt(src.source, bounds.Min.X+x-1, bounds.Min.Y+y-1)
+	case *orientedTIFFImage:
+		point, ok := src.sourcePoint(x, y)
+		if !ok {
+			return color.Gray{}
+		}
+		return GrayAt(src.source, point.X, point.Y)
+	case *planarTIFFImage:
+		if src.cmyk {
+			return src.cmykGrayAt(x, y)
+		}
+	}
+	if src, ok := img.(*image.Gray); ok {
+		return src.GrayAt(x, y)
+	}
+	if src, ok := img.(*image.Paletted); ok {
+		return color.GrayModel.Convert(src.At(x, y)).(color.Gray)
+	}
+	if src, ok := img.(image.RGBA64Image); ok {
+		r, g, b, _ := src.RGBA64At(x, y).RGBA()
+		return color.Gray{Y: uint8((19595*r + 38470*g + 7471*b + 1<<15) >> 24)}
+	}
+	return color.GrayModel.Convert(img.At(x, y)).(color.Gray)
+}
+
+// NRGBAAt 读取八位非预乘像素，缩减位深时保留原始颜色分量
+// 入参: img 图片对象, x X坐标, y Y坐标
+// 返回: color.NRGBA NRGBA像素
+func NRGBAAt(img image.Image, x, y int) color.NRGBA {
+	switch src := img.(type) {
+	case *image.NRGBA:
+		return src.NRGBAAt(x, y)
+	case *image.NRGBA64:
+		c := src.NRGBA64At(x, y)
+		return color.NRGBA{R: uint8(c.R >> 8), G: uint8(c.G >> 8), B: uint8(c.B >> 8), A: uint8(c.A >> 8)}
+	case interface{ NRGBAAt(int, int) color.NRGBA }:
+		return src.NRGBAAt(x, y)
+	case interface{ NRGBA64At(int, int) color.NRGBA64 }:
+		c := src.NRGBA64At(x, y)
+		return color.NRGBA{R: uint8(c.R >> 8), G: uint8(c.G >> 8), B: uint8(c.B >> 8), A: uint8(c.A >> 8)}
+	case *image.RGBA, *image.RGBA64, *image.Gray, *image.Gray16, *image.Alpha, *image.Alpha16, *image.CMYK, *image.YCbCr, *image.NYCbCrA:
+		c := src.(image.RGBA64Image).RGBA64At(x, y)
+		if c.A == 0 {
+			return color.NRGBA{}
+		}
+		r, g, b, a := uint32(c.R), uint32(c.G), uint32(c.B), uint32(c.A)
+		if a != 0xffff {
+			r = r * 0xffff / a
+			g = g * 0xffff / a
+			b = b * 0xffff / a
+		}
+		return color.NRGBA{R: uint8(r >> 8), G: uint8(g >> 8), B: uint8(b >> 8), A: uint8(a >> 8)}
+	}
+	value := img.At(x, y)
+	if c, ok := value.(color.NRGBA64); ok {
+		return color.NRGBA{R: uint8(c.R >> 8), G: uint8(c.G >> 8), B: uint8(c.B >> 8), A: uint8(c.A >> 8)}
+	}
+	return color.NRGBAModel.Convert(value).(color.NRGBA)
+}
+
+// AlphaAt 读取十六位透明度，原生图像避免颜色装箱
+// 入参: img 图像, x 横坐标, y 纵坐标
+// 返回: uint32 十六位透明度
+func AlphaAt(img image.Image, x, y int) uint32 {
+	switch source := img.(type) {
+	case *maskedTIFFImage:
+		return source.alphaAt(x, y)
+	case *image.YCbCr, *image.CMYK, *image.Gray, *image.Gray16:
+		return 65535
+	case *image.NYCbCrA:
+		if !image.Pt(x, y).In(source.Rect) {
+			return 0
+		}
+		return uint32(source.A[source.AOffset(x, y)]) * 257
+	case *orientedTIFFImage:
+		point, ok := source.sourcePoint(x, y)
+		if !ok {
+			return 0
+		}
+		return AlphaAt(source.source, point.X, point.Y)
+	case *planarTIFFImage:
+		if !image.Pt(x, y).In(source.bounds) {
+			return 0
+		}
+		if source.alpha != 0 {
+			index := 3
+			if source.cmyk {
+				index = 4
+			} else if source.gray || len(source.palette) != 0 {
+				index = 1
+			}
+			return uint32(source.sampleAt(index, x, y))
+		}
+		if len(source.palette) != 0 {
+			index := uint32(source.sampleAt(0, x, y)) * uint32(len(source.palette)-1) / 65535
+			return uint32(source.palette[index].A)
+		}
+		return 65535
+	case *image.RGBA:
+		if !(image.Point{X: x, Y: y}).In(source.Rect) {
+			return 0
+		}
+		return uint32(source.Pix[source.PixOffset(x, y)+3]) * 257
+	case *image.RGBA64:
+		if !(image.Point{X: x, Y: y}).In(source.Rect) {
+			return 0
+		}
+		i := source.PixOffset(x, y) + 6
+		return uint32(source.Pix[i])<<8 | uint32(source.Pix[i+1])
+	case *image.NRGBA:
+		return uint32(source.NRGBAAt(x, y).A) * 257
+	case *image.NRGBA64:
+		return uint32(source.NRGBA64At(x, y).A)
+	case *image.Alpha:
+		return uint32(source.AlphaAt(x, y).A) * 257
+	case *image.Alpha16:
+		return uint32(source.Alpha16At(x, y).A)
+	}
+	if source, ok := img.(image.RGBA64Image); ok {
+		return uint32(source.RGBA64At(x, y).A)
+	}
+	_, _, _, alpha := img.At(x, y).RGBA()
+	return alpha
+}
+
+// HighPrecision 判断颜色模型及调色板是否需要保留十六位采样
+// 入参: img 图片对象
+// 返回: bool 是否使用十六位颜色或透明度
+func HighPrecision(img image.Image) bool {
+	model := img.ColorModel()
+	if palette, ok := model.(color.Palette); ok {
+		for _, value := range palette {
+			switch value.(type) {
+			case color.RGBA, color.NRGBA, color.Gray, color.Alpha, color.CMYK, color.YCbCr, color.NYCbCrA:
+			default:
+				pixel := color.NRGBA64Model.Convert(value).(color.NRGBA64)
+				if pixel.R%257 != 0 || pixel.G%257 != 0 || pixel.B%257 != 0 || pixel.A%257 != 0 {
+					return true
+				}
+			}
+		}
+		return false
+	}
+	return model == color.NRGBA64Model || model == color.RGBA64Model || model == color.Gray16Model || model == color.Alpha16Model
+}
+
+// NRGBA64At 读取十六位非预乘像素，保留透明像素颜色，原生图像避免颜色装箱
+// 入参: img 图片对象, x X坐标, y Y坐标
+// 返回: color.NRGBA64 NRGBA64像素
+func NRGBA64At(img image.Image, x, y int) color.NRGBA64 {
+	switch src := img.(type) {
+	case interface{ NRGBA64At(int, int) color.NRGBA64 }:
+		return src.NRGBA64At(x, y)
+	case *image.NRGBA:
+		c := src.NRGBAAt(x, y)
+		return color.NRGBA64{R: uint16(c.R) * 257, G: uint16(c.G) * 257, B: uint16(c.B) * 257, A: uint16(c.A) * 257}
+	case *image.Gray:
+		v := uint16(src.GrayAt(x, y).Y) * 257
+		return color.NRGBA64{R: v, G: v, B: v, A: 0xffff}
+	case *image.Gray16:
+		c := src.Gray16At(x, y)
+		return color.NRGBA64{R: c.Y, G: c.Y, B: c.Y, A: 0xffff}
+	case *image.Alpha, *image.Alpha16:
+		c := src.(image.RGBA64Image).RGBA64At(x, y)
+		if c.A == 0 {
+			return color.NRGBA64{}
+		}
+		return color.NRGBA64{R: 0xffff, G: 0xffff, B: 0xffff, A: c.A}
+	case *image.RGBA, *image.RGBA64, *image.CMYK, *image.YCbCr, *image.NYCbCrA:
+		c := src.(image.RGBA64Image).RGBA64At(x, y)
+		if c.A == 0 {
+			return color.NRGBA64{}
+		}
+		r, g, b, a := uint32(c.R), uint32(c.G), uint32(c.B), uint32(c.A)
+		if a != 0xffff {
+			r = r * 0xffff / a
+			g = g * 0xffff / a
+			b = b * 0xffff / a
+		}
+		return color.NRGBA64{R: uint16(r), G: uint16(g), B: uint16(b), A: c.A}
+	}
+	value := img.At(x, y)
+	if c, ok := value.(color.NRGBA); ok {
+		return color.NRGBA64{R: uint16(c.R) * 257, G: uint16(c.G) * 257, B: uint16(c.B) * 257, A: uint16(c.A) * 257}
+	}
+	return color.NRGBA64Model.Convert(value).(color.NRGBA64)
+}
+
+// transparentEdgeColor 获取透明像素相邻的可见颜色
+// 入参: source 图片对象, x X坐标, y Y坐标
+// 返回: color.NRGBA 颜色, bool 是否存在
+func transparentEdgeColor(source image.Image, x, y int) (color.NRGBA, bool) {
+	img, ok := source.(*image.NRGBA)
+	if !ok {
+		bounds := source.Bounds()
+		var best color.NRGBA
+		for ny := max(y-1, bounds.Min.Y); ny < min(y+2, bounds.Max.Y); ny++ {
+			for nx := max(x-1, bounds.Min.X); nx < min(x+2, bounds.Max.X); nx++ {
+				if nx == x && ny == y {
+					continue
+				}
+				pixel := NRGBAAt(source, nx, ny)
+				if pixel.A > best.A {
+					best = pixel
+					if best.A == 255 {
+						best.A = 1
+						return best, true
+					}
+				}
+			}
+		}
+		if best.A == 0 {
+			return color.NRGBA{}, false
+		}
+		best.A = 1
+		return best, true
+	}
+	bounds := img.Bounds()
+	best, alpha := 0, uint8(0)
+	left, right := max(x-1, bounds.Min.X), min(x+2, bounds.Max.X)
+scan:
+	for ny := max(y-1, bounds.Min.Y); ny < min(y+2, bounds.Max.Y); ny++ {
+		offset := img.PixOffset(left, ny)
+		for nx := left; nx < right; nx++ {
+			if (nx != x || ny != y) && img.Pix[offset+3] > alpha {
+				best, alpha = offset, img.Pix[offset+3]
+				if alpha == 255 {
+					break scan
+				}
+			}
+			offset += 4
+		}
+	}
+	if alpha == 0 {
+		return color.NRGBA{}, false
+	}
+	return color.NRGBA{R: img.Pix[best], G: img.Pix[best+1], B: img.Pix[best+2], A: 1}, true
+}
+
+// transparentPaddingColor 获取透明补齐颜色
+// 入参: c 边缘颜色
+// 返回: color.NRGBA 补齐颜色
+func transparentPaddingColor(c color.NRGBA) color.NRGBA {
+	c.A = 1
+	return c
+}
+
+// WithTransparentEdge 扫描透明边缘并共享只读像素，保留原图采样精度
+// 入参: ctx 取消上下文，nil使用后台上下文, img 图片对象
+// 返回: image.Image 补边图像, int 补边像素数, error 解码或取消错误
+func WithTransparentEdge(ctx context.Context, img image.Image) (image.Image, int, error) {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, 0, err
+	}
+	if img == nil {
+		return img, 0, nil
+	}
+	bounds := img.Bounds()
+	w, h := bounds.Dx(), bounds.Dy()
+	if w == 0 || h == 0 {
+		return img, 0, nil
+	}
+	if src, ok := img.(*EncodedImage); ok && src.MIME() == "image/jpeg" {
+		if src.profile != nil || src.config.ColorModel == color.CMYKModel {
+			pixels, err := src.ImageContext(ctx)
+			return pixels, 0, err
+		}
+		return img, 0, nil
+	}
+	source, err := PixelDataContext(ctx, img)
+	if err != nil {
+		return nil, 0, err
+	}
+	if encoded, ok := img.(*EncodedImage); ok && (encoded.profile != nil || encoded.pngColor != nil) {
+		img = source
+	}
+	switch source.(type) {
+	case *image.Gray, *image.Gray16, *image.YCbCr, *image.CMYK:
+		return img, 0, nil
+	}
+	hasZero, hasVisible := false, false
+	var pixels []byte
+	var stride, step int
+	wideAlpha := false
+	switch src := source.(type) {
+	case *image.NRGBA:
+		pixels, stride, step = src.Pix, src.Stride, 4
+	case *image.RGBA:
+		pixels, stride, step = src.Pix, src.Stride, 4
+	case *image.Alpha:
+		pixels, stride, step = src.Pix, src.Stride, 1
+	case *image.NRGBA64:
+		pixels, stride, step, wideAlpha = src.Pix, src.Stride, 8, true
+	case *image.RGBA64:
+		pixels, stride, step, wideAlpha = src.Pix, src.Stride, 8, true
+	case *image.Alpha16:
+		pixels, stride, step, wideAlpha = src.Pix, src.Stride, 2, true
+	case *colorImage:
+		pixels, stride, step, wideAlpha = src.Pix, src.Stride, 8, true
+	}
+	if pixels != nil {
+		hasZero = pixels[step-1] == 0 && (!wideAlpha || pixels[step-2] == 0)
+		hasVisible = !hasZero
+	scan:
+		for y := 0; y < h; y++ {
+			if err := ctx.Err(); err != nil {
+				return nil, 0, err
+			}
+			offset := y*stride + step - 1
+			for x := 0; x < w; x++ {
+				if x&255 == 0 {
+					if err := ctx.Err(); err != nil {
+						return nil, 0, err
+					}
+				}
+				if (pixels[offset] == 0 && (!wideAlpha || pixels[offset-1] == 0)) != hasZero {
+					hasZero, hasVisible = true, true
+					break scan
+				}
+				offset += step
+			}
+		}
+	} else {
+		for y := bounds.Min.Y; y < bounds.Max.Y && !(hasZero && hasVisible); y++ {
+			if err := ctx.Err(); err != nil {
+				return nil, 0, err
+			}
+			for x := bounds.Min.X; x < bounds.Max.X; x++ {
+				if (x-bounds.Min.X)&255 == 0 {
+					if err := ctx.Err(); err != nil {
+						return nil, 0, err
+					}
+				}
+				if AlphaAt(source, x, y) == 0 {
+					hasZero = true
+				} else {
+					hasVisible = true
+				}
+				if hasZero && hasVisible {
+					break
+				}
+			}
+		}
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, 0, err
+	}
+	if !hasZero || !hasVisible {
+		return img, 0, nil
+	}
+	if HighPrecision(source) {
+		return &transparentEdgeImage64{source: source, rect: image.Rect(0, 0, w+2, h+2)}, 1, nil
+	}
+	return &transparentEdgeImage{source: source, rect: image.Rect(0, 0, w+2, h+2)}, 1, nil
+}

internal/base/image/input.go

@@ -0,0 +1,36 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package image
+
+import (
+	"context"
+	"io"
+)
+
+// contextInput 在读取图像编码时检查调用方取消状态
+type contextInput struct {
+	io.ReadCloser
+	ctx context.Context
+}
+
+// Read 检查取消状态后读取原始数据
+// 入参: data 数据缓冲区
+// 返回: int 读取字节数, error 读取或取消错误
+func (r contextInput) Read(data []byte) (int, error) {
+	if err := r.ctx.Err(); err != nil {
+		return 0, err
+	}
+	return r.ReadCloser.Read(data)
+}

internal/base/image/metadata.go

@@ -0,0 +1,422 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package image
+
+import (
+	"bytes"
+	"context"
+	"encoding/binary"
+	"fmt"
+	"hash/crc32"
+	"image"
+	"math"
+	"math/big"
+)
+
+// PNGDensityChunkSize 为PNG像素密度块占用的字节数
+const PNGDensityChunkSize = 21
+
+// Density 保存横纵像素密度，Unit为0表示比例、1表示每米像素数
+type Density struct {
+	X, Y float64
+	Unit byte
+}
+
+// PageInfo 图片方向与像素密度，不改变原始编码
+type PageInfo struct {
+	Orientation int
+	XDPI, YDPI  float64
+}
+
+// PageMetadataContext 读取图片方向与密度，扫描目录或数据段时响应取消
+// TIFF方向由解码器处理，JPEG的EXIF密度优先于JFIF
+// 入参: ctx 取消上下文, data 图片数据, format 图像格式, dpi 缺少物理密度时使用的DPI
+// 返回: PageInfo 方向与横纵DPI, error 元数据或取消错误
+func PageMetadataContext(ctx context.Context, data []byte, format string, dpi float64) (PageInfo, error) {
+	info := PageInfo{Orientation: 1, XDPI: dpi, YDPI: dpi}
+	if err := ctx.Err(); err != nil {
+		return info, err
+	}
+	var exif []byte
+	var directory uint32
+	scaleX, scaleY := 1.0, 1.0
+	if format == "tiff" {
+		layout, err := ReadTIFFLayoutContext(ctx, bytes.NewReader(data))
+		if err != nil {
+			return info, err
+		}
+		directory = layout.Offset
+		exif = data
+		original, display := layout.size(), layout.DisplaySize()
+		scaleX, scaleY = float64(display.X)/float64(original.X), float64(display.Y)/float64(original.Y)
+	}
+	if format == "bmp" && len(data) >= 54 && binary.LittleEndian.Uint32(data[14:18]) >= 40 {
+		x := int32(binary.LittleEndian.Uint32(data[38:42]))
+		y := int32(binary.LittleEndian.Uint32(data[42:46]))
+		if x > 0 && y > 0 {
+			info.XDPI, info.YDPI = float64(x)*0.0254, float64(y)*0.0254
+		}
+	}
+	if format == "png" {
+		for offset := 8; offset+12 <= len(data); {
+			if err := ctx.Err(); err != nil {
+				return info, err
+			}
+			n := uint64(binary.BigEndian.Uint32(data[offset:]))
+			if n > uint64(len(data)-offset-12) {
+				return info, fmt.Errorf("truncated PNG chunk")
+			}
+			end := offset + 8 + int(n)
+			kind, payload := string(data[offset+4:offset+8]), data[offset+8:end]
+			if kind == "pHYs" || kind == "eXIf" {
+				if crc32.ChecksumIEEE(data[offset+4:end]) != binary.BigEndian.Uint32(data[end:]) {
+					return info, fmt.Errorf("invalid PNG %s checksum", kind)
+				}
+			}
+			if kind == "pHYs" && len(payload) == 9 {
+				x, y := float64(binary.BigEndian.Uint32(payload)), float64(binary.BigEndian.Uint32(payload[4:]))
+				if x > 0 && y > 0 {
+					if payload[8] == 1 {
+						info.XDPI, info.YDPI = x*0.0254, y*0.0254
+					} else if payload[8] == 0 {
+						info.YDPI = dpi * y / x
+					}
+				}
+			} else if kind == "eXIf" {
+				exif = payload
+			}
+			offset = end + 4
+			if kind == "IEND" {
+				break
+			}
+		}
+	} else if format == "jpeg" {
+		for offset := 2; offset < len(data); {
+			if err := ctx.Err(); err != nil {
+				return info, err
+			}
+			if data[offset] != 0xff {
+				return info, fmt.Errorf("invalid JPEG marker")
+			}
+			for offset < len(data) && data[offset] == 0xff {
+				offset++
+			}
+			if offset >= len(data) {
+				break
+			}
+			marker := data[offset]
+			offset++
+			if marker == 0xda || marker == 0xd9 {
+				break
+			}
+			if marker == 0x01 || marker >= 0xd0 && marker <= 0xd7 {
+				continue
+			}
+			if offset+2 > len(data) {
+				return info, fmt.Errorf("truncated JPEG marker")
+			}
+			n := int(binary.BigEndian.Uint16(data[offset:]))
+			if n < 2 || n > len(data)-offset {
+				return info, fmt.Errorf("truncated JPEG segment")
+			}
+			payload := data[offset+2 : offset+n]
+			if marker == 0xe0 && len(payload) >= 14 && bytes.Equal(payload[:5], []byte("JFIF\x00")) {
+				x, y := float64(binary.BigEndian.Uint16(payload[8:])), float64(binary.BigEndian.Uint16(payload[10:]))
+				if x > 0 && y > 0 {
+					switch payload[7] {
+					case 0:
+						info.YDPI = dpi * y / x
+					case 1:
+						info.XDPI, info.YDPI = x, y
+					case 2:
+						info.XDPI, info.YDPI = x*2.54, y*2.54
+					}
+				}
+			} else if marker == 0xe1 && bytes.HasPrefix(payload, []byte("Exif\x00\x00")) {
+				exif = payload[6:]
+			}
+			offset += n
+		}
+	}
+	if len(exif) != 0 {
+		orientation, x, y, err := imageExifMetadata(exif, dpi, directory)
+		if err != nil {
+			return info, err
+		}
+		info.Orientation = orientation
+		if (format == "jpeg" || format == "tiff") && x > 0 && y > 0 {
+			info.XDPI, info.YDPI = x, y
+		}
+		if format == "tiff" {
+			if orientation >= 5 {
+				info.XDPI, info.YDPI = info.YDPI, info.XDPI
+			}
+			info.Orientation = 1
+		}
+	}
+	info.XDPI, info.YDPI = info.XDPI*scaleX, info.YDPI*scaleY
+	return info, ctx.Err()
+}
+
+// imageExifMetadata 只读取主图IFD中的方向和密度，不跟随缩略图与其他目录
+// 入参: data TIFF或EXIF数据, dpi 无绝对密度单位时的横向DPI，零值不换算, directory 目录偏移，零值使用首目录
+// 返回: int EXIF方向值，未声明时为1, float64 横向DPI, float64 纵向DPI, error 元数据错误
+func imageExifMetadata(data []byte, dpi float64, directory uint32) (int, float64, float64, error) {
+	invalid := fmt.Errorf("invalid EXIF image metadata")
+	if len(data) < 8 {
+		return 0, 0, 0, invalid
+	}
+	var order binary.ByteOrder
+	switch string(data[:2]) {
+	case "II":
+		order = binary.LittleEndian
+	case "MM":
+		order = binary.BigEndian
+	default:
+		return 0, 0, 0, invalid
+	}
+	if order.Uint16(data[2:]) != 42 {
+		return 0, 0, 0, invalid
+	}
+	offset := uint64(order.Uint32(data[4:]))
+	if directory != 0 {
+		offset = uint64(directory)
+	}
+	if offset < 8 || offset+2 > uint64(len(data)) {
+		return 0, 0, 0, invalid
+	}
+	count := uint64(order.Uint16(data[offset:]))
+	if count*12+offset+6 > uint64(len(data)) {
+		return 0, 0, 0, invalid
+	}
+	orientation, unit := 1, 2
+	var x, y float64
+	for i := uint64(0); i < count; i++ {
+		entry := data[offset+2+i*12 : offset+14+i*12]
+		tag, kind, count := order.Uint16(entry), order.Uint16(entry[2:]), order.Uint32(entry[4:])
+		switch tag {
+		case 0x112, 0x128:
+			if kind != 3 || count != 1 {
+				return 0, 0, 0, invalid
+			}
+			value := int(order.Uint16(entry[8:]))
+			if tag == 0x112 {
+				if value < 1 || value > 8 {
+					return 0, 0, 0, invalid
+				}
+				orientation = value
+			} else {
+				unit = value
+			}
+		case 0x11a, 0x11b:
+			at := uint64(order.Uint32(entry[8:]))
+			if kind != 5 || count != 1 || at+8 > uint64(len(data)) {
+				return 0, 0, 0, invalid
+			}
+			n, d := order.Uint32(data[at:]), order.Uint32(data[at+4:])
+			if n > 0 && d > 0 {
+				if tag == 0x11a {
+					x = float64(n) / float64(d)
+				} else {
+					y = float64(n) / float64(d)
+				}
+			}
+		}
+	}
+	if unit == 3 {
+		x, y = x*2.54, y*2.54
+	} else if unit == 1 && dpi > 0 && x > 0 && y > 0 {
+		x, y = dpi, dpi*y/x
+	} else if unit != 2 {
+		x, y = 0, 0
+	}
+	return orientation, x, y, nil
+}
+
+// BMPDensity 提取已校验BMP头中的每米像素数
+// 入参: data 含至少40字节信息头的BMP编码
+// 返回: Density 像素密度, bool 密度是否可保留
+func BMPDensity(data []byte) (Density, bool) {
+	xdpi, ydpi := int32(binary.LittleEndian.Uint32(data[38:42])), int32(binary.LittleEndian.Uint32(data[42:46]))
+	if xdpi < 0 || ydpi < 0 {
+		return Density{}, false
+	}
+	return Density{X: float64(xdpi), Y: float64(ydpi), Unit: 1}, true
+}
+
+// TIFFConversionDensity 校验可转换的TIFF字段并提取规范化后的像素密度
+// 色彩配置、预乘透明度、扩展字段及其他目录需保留原始编码
+// 入参: data TIFF编码, layout 已校验的主图布局
+// 返回: Density PNG像素密度, bool 是否可完整转换
+func TIFFConversionDensity(data []byte, layout TIFFLayout) (Density, bool) {
+	var density Density
+	var order binary.ByteOrder = binary.LittleEndian
+	if data[0] == 'M' {
+		order = binary.BigEndian
+	}
+	if layout.Next != 0 || layout.Offset != order.Uint32(data[4:]) || layout.Reduced {
+		return density, false
+	}
+	offset := int(layout.Offset)
+	count := int(order.Uint16(data[offset:]))
+	unit := uint32(2)
+	var resolutions [2][2]uint32
+	for i := range count {
+		entry := data[offset+2+i*12 : offset+14+i*12]
+		tag, kind, number := order.Uint16(entry), order.Uint16(entry[2:]), order.Uint32(entry[4:])
+		value := order.Uint32(entry[8:])
+		if kind == 3 && number == 1 {
+			value = uint32(order.Uint16(entry[8:]))
+		}
+		switch tag {
+		case 256, 257, 258, 259, 273, 274, 277, 278, 279, 320, 322, 323, 324, 325:
+		case 262:
+			if value == 5 {
+				return density, false
+			}
+		case 254:
+			if value != 0 {
+				return density, false
+			}
+		case 255:
+			if value != 1 {
+				return density, false
+			}
+		case 266:
+			if kind != 3 || number != 1 || value != 1 && value != 2 {
+				return density, false
+			}
+		case 284:
+			if kind != 3 || number != 1 || value != 1 && value != 2 {
+				return density, false
+			}
+		case 292, 293:
+			mask := uint32(7)
+			if tag == 293 {
+				mask = 2
+			}
+			if kind != 4 || number != 1 || value & ^mask != 0 {
+				return density, false
+			}
+		case 317:
+			if kind != 3 || number != 1 || value != 1 && value != 2 {
+				return density, false
+			}
+		case 338:
+			if kind != 3 || number != 1 || value != 2 {
+				return density, false
+			}
+		case 339:
+			if kind != 3 || number == 0 || number > 4 {
+				return density, false
+			}
+			values := entry[8:]
+			if number > 2 {
+				if uint64(value)+uint64(number)*2 > uint64(len(data)) {
+					return density, false
+				}
+				values = data[value:]
+			}
+			for j := uint32(0); j < number; j++ {
+				if order.Uint16(values[j*2:]) != 1 {
+					return density, false
+				}
+			}
+		case 282, 283:
+			if kind != 5 || number != 1 || uint64(value)+8 > uint64(len(data)) {
+				return density, false
+			}
+			resolutions[tag-282] = [2]uint32{order.Uint32(data[value:]), order.Uint32(data[value+4:])}
+		case 296:
+			if kind != 3 || number != 1 || value < 1 || value > 3 {
+				return density, false
+			}
+			unit = value
+		default:
+			return density, false
+		}
+	}
+	if resolutions == [2][2]uint32{} {
+		return density, true
+	}
+	x, y := resolutions[0], resolutions[1]
+	if x[0] == 0 || x[1] == 0 || y[0] == 0 || y[1] == 0 {
+		return density, false
+	}
+	if unit == 1 {
+		a, b := uint64(x[0])*uint64(y[1]), uint64(y[0])*uint64(x[1])
+		divisor, next := a, b
+		for next != 0 {
+			divisor, next = next, divisor%next
+		}
+		density.X, density.Y = float64(a/divisor), float64(b/divisor)
+	} else {
+		factor := 1 / 0.0254
+		if unit == 3 {
+			factor = 100
+		}
+		density = Density{X: float64(x[0]) / float64(x[1]) * factor, Y: float64(y[0]) / float64(y[1]) * factor, Unit: 1}
+	}
+	if math.Round(density.X) < 1 || math.Round(density.Y) < 1 || math.Round(density.X) > math.MaxInt32 || math.Round(density.Y) > math.MaxInt32 {
+		return density, false
+	}
+	if layout.Orientation >= 5 {
+		density.X, density.Y = density.Y, density.X
+	}
+	return density, true
+}
+
+// Scale 按最终像素尺寸保留绝对密度或精确相对比例
+// 入参: before 原始像素尺寸, after 最终像素尺寸
+// 返回: Density 缩放后密度, bool 相对比例是否可完整保留
+func (density Density) Scale(before, after image.Point) (Density, bool) {
+	hasDensity := density.X != 0 || density.Y != 0
+	if hasDensity && before != after {
+		if density.Unit == 0 {
+			ratio := new(big.Rat).SetFrac64(int64(density.X)*int64(after.X), int64(density.Y)*int64(after.Y))
+			ratio.Mul(ratio, new(big.Rat).SetFrac64(int64(before.Y), int64(before.X)))
+			if ratio.Num().BitLen() > 31 || ratio.Denom().BitLen() > 31 {
+				return density, false
+			}
+			density.X, density.Y = float64(ratio.Num().Int64()), float64(ratio.Denom().Int64())
+		} else {
+			density.X *= float64(after.X) / float64(before.X)
+			density.Y *= float64(after.Y) / float64(before.Y)
+		}
+	}
+	return density, true
+}
+
+// WithPNGDensity 在无密度块的PNG头后插入pHYs，保留源编码不变
+// 入参: data 完整PNG编码, density 像素密度
+// 返回: []byte 带密度的编码, bool 密度是否可完整保留
+func WithPNGDensity(data []byte, density Density) ([]byte, bool) {
+	x, y := math.Round(density.X), math.Round(density.Y)
+	if x > math.MaxInt32 || y > math.MaxInt32 || density.X > 0 && x < 1 || density.Y > 0 && y < 1 {
+		return nil, false
+	}
+	chunk := make([]byte, 21)
+	binary.BigEndian.PutUint32(chunk, 9)
+	copy(chunk[4:], "pHYs")
+	binary.BigEndian.PutUint32(chunk[8:], uint32(x))
+	binary.BigEndian.PutUint32(chunk[12:], uint32(y))
+	chunk[16] = density.Unit
+	binary.BigEndian.PutUint32(chunk[17:], crc32.ChecksumIEEE(chunk[4:17]))
+	output := make([]byte, 0, len(data)+PNGDensityChunkSize)
+	output = append(output, data[:33]...)
+	output = append(output, chunk...)
+	output = append(output, data[33:]...)
+	return output, true
+}

internal/base/image/scale.go

@@ -0,0 +1,487 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package image
+
+import (
+	"image"
+	"image/color"
+	"math"
+	"slices"
+
+	"golang.org/x/image/draw"
+	"golang.org/x/image/math/f64"
+)
+
+// rasterScaleBufferLimit 限制整像素缩放器的浮点中间缓冲，超出时使用逐行采样
+const rasterScaleBufferLimit = 8 << 20
+
+// rasterAxisSample 保存目标像素及其归一化源采样权重
+type rasterAxisSample struct {
+	pixel   int
+	first   int
+	weights []float64
+}
+
+// rasterImagePixel 保存未取整或裁切的预乘颜色累积值
+type rasterImagePixel struct {
+	r, g, b, a float64
+}
+
+// rasterImageRow 保存正在累积的目标行
+type rasterImageRow struct {
+	sample rasterAxisSample
+	values []rasterImagePixel
+}
+
+// rasterImageSource 为通用图片提供预乘十六位采样
+type rasterImageSource struct{ image.Image }
+
+// RGBA64At 读取通用颜色的原始预乘分量
+// 入参: x 横向坐标, y 纵向坐标
+// 返回: color.RGBA64 预乘颜色
+func (s rasterImageSource) RGBA64At(x, y int) color.RGBA64 {
+	r, g, b, a := s.At(x, y).RGBA()
+	return color.RGBA64{R: uint16(r), G: uint16(g), B: uint16(b), A: uint16(a)}
+}
+
+// drawRasterAxisImage 轴向缩放复用逐行采样，细轴按面积覆盖并保留镜像与小数坐标
+// 入参: dst 目标图像, src 源图像, m 像素变换, op 合成操作
+// 返回: bool 是否使用轴向采样
+func drawRasterAxisImage(dst draw.Image, src image.Image, m [6]float64, op draw.Op) bool {
+	sx, sy := math.Abs(m[0]), math.Abs(m[3])
+	if m[1] != 0 || m[2] != 0 || sx == 0 || sy == 0 {
+		return false
+	}
+	for _, v := range m {
+		if math.IsNaN(v) || math.IsInf(v, 0) {
+			return false
+		}
+	}
+	b := src.Bounds()
+	if b.Empty() {
+		return true
+	}
+	r := TransformBounds(b, m, dst.Bounds())
+	if r.Empty() {
+		return true
+	}
+	if float64(r.Dx())*math.Min(float64(r.Dy()), math.Ceil(4*math.Max(1, sy))+2) > rasterScaleBufferLimit/32 {
+		if sx*float64(b.Dx()) < 1 || sy*float64(b.Dy()) < 1 {
+			return drawRasterFootprintImage(dst, src, m, op, r)
+		}
+		return false
+	}
+	if !rasterFootprintWeightsFit(b, r, m) {
+		return drawRasterFootprintImage(dst, src, m, op, r)
+	}
+	xs := rasterImageAxis(r.Min.X, r.Max.X, b.Min.X, b.Max.X, m[0], m[4])
+	ys := rasterImageAxis(r.Min.Y, r.Max.Y, b.Min.Y, b.Max.Y, m[3], m[5])
+	if len(xs) == 0 || len(ys) == 0 {
+		return true
+	}
+	if m[3] < 0 {
+		slices.Reverse(ys)
+	}
+	pixels, ok := src.(image.RGBA64Image)
+	if !ok {
+		pixels = rasterImageSource{src}
+	}
+	width := len(xs)
+	horizontal := make([]rasterImagePixel, width)
+	output := image.NewRGBA64(image.Rect(0, 0, width, 1))
+	var active []rasterImageRow
+	var free [][]rasterImagePixel
+	next := 0
+	for y := ys[0].first; next < len(ys) || len(active) != 0; y++ {
+		if len(active) == 0 && y < ys[next].first {
+			y = ys[next].first
+		}
+		for next < len(ys) && ys[next].first == y {
+			var row []rasterImagePixel
+			if n := len(free); n != 0 {
+				row, free = free[n-1], free[:n-1]
+				clear(row)
+			} else {
+				row = make([]rasterImagePixel, width)
+			}
+			active = append(active, rasterImageRow{sample: ys[next], values: row})
+			next++
+		}
+		rasterImageHorizontal(horizontal, pixels, xs, y)
+		n := 0
+		for _, row := range active {
+			weight := row.sample.weights[y-row.sample.first]
+			if weight != 0 {
+				for x, value := range horizontal {
+					p := &row.values[x]
+					p.r += value.r * weight
+					p.g += value.g * weight
+					p.b += value.b * weight
+					p.a += value.a * weight
+				}
+			}
+			if y+1 == row.sample.first+len(row.sample.weights) {
+				rasterImageWriteRow(dst, output, row.values, xs[0].pixel, row.sample.pixel, op)
+				free = append(free, row.values)
+			} else {
+				active[n] = row
+				n++
+			}
+		}
+		active = active[:n]
+	}
+	return true
+}
+
+// rasterImageAxis 按连续源坐标生成CatmullRom权重，亚像素细轴使用面积覆盖权重
+// 入参: first 目标起点, end 目标终点, source 源起点, limit 源终点, scale 缩放比例, offset 平移距离
+// 返回: []rasterAxisSample 轴向采样表
+func rasterImageAxis(first, end, source, limit int, scale, offset float64) []rasterAxisSample {
+	if math.Abs(scale)*float64(limit-source) < 1 {
+		return rasterImageFootprintAxis(first, end, source, limit, scale, offset)
+	}
+	result := make([]rasterAxisSample, 0, end-first)
+	argument := math.Min(1, math.Abs(scale))
+	support := draw.CatmullRom.Support / argument
+	count := 0
+	for pixel := first; pixel < end; pixel++ {
+		center := (float64(pixel) + .5 - offset) / scale
+		if center < float64(source) || center >= float64(limit) {
+			continue
+		}
+		center -= .5
+		start := int(max(float64(source), math.Floor(center-support)))
+		stop := int(min(float64(limit), math.Ceil(center+support)))
+		count += stop - start
+		result = append(result, rasterAxisSample{pixel: pixel, first: start})
+	}
+	buffer := make([]float64, count)
+	for index := range result {
+		sample := &result[index]
+		center := (float64(sample.pixel)+.5-offset)/scale - .5
+		start := sample.first
+		stop := int(min(float64(limit), math.Ceil(center+support)))
+		n := stop - start
+		weights := buffer[:n:n]
+		buffer = buffer[n:]
+		total := 0.0
+		for i := range weights {
+			distance := math.Abs((float64(start+i) - center) * argument)
+			if distance < draw.CatmullRom.Support {
+				weights[i] = draw.CatmullRom.At(distance)
+				total += weights[i]
+			}
+		}
+		for i := range weights {
+			weights[i] /= total
+		}
+		sample.weights = weights
+	}
+	return result
+}
+
+// rasterFootprintWeightsFit 检查细轴权重表的合计预算，乘法前排除溢出
+// 入参: source 源边界, target 目标范围, m 像素变换
+// 返回: bool 权重表是否符合预算
+func rasterFootprintWeightsFit(source, target image.Rectangle, m [6]float64) bool {
+	budget := rasterScaleBufferLimit / 8
+	for _, axis := range [...]struct {
+		source, target int
+		scale          float64
+	}{{source.Dx(), target.Dx(), m[0]}, {source.Dy(), target.Dy(), m[3]}} {
+		if math.Abs(axis.scale)*float64(axis.source) < 1 && axis.target > 0 {
+			n, samples := axis.source, min(2, axis.target)
+			if n > budget/samples {
+				return false
+			}
+			budget -= n * samples
+		}
+	}
+	return true
+}
+
+// rasterImageWeightSpan 提供单个目标像素的源范围和权重，不分配整轴权重表
+// 入参: pixel 目标像素, source 源起点, limit 源终点, scale 缩放比例, offset 平移距离
+// 返回: int 源起点, int 源终点, func(int)float64 源权重
+func rasterImageWeightSpan(pixel, source, limit int, scale, offset float64) (int, int, func(int) float64) {
+	if math.Abs(scale)*float64(limit-source) < 1 {
+		left, right := (float64(pixel)-offset)/scale, (float64(pixel+1)-offset)/scale
+		if right < left {
+			left, right = right, left
+		}
+		if right <= float64(source) || left >= float64(limit) {
+			return 0, 0, nil
+		}
+		return source, limit, func(x int) float64 {
+			return math.Max(0, math.Min(float64(x)+1, right)-math.Max(float64(x), left)) * math.Abs(scale)
+		}
+	}
+	center := (float64(pixel) + .5 - offset) / scale
+	if center < float64(source) || center >= float64(limit) {
+		return 0, 0, nil
+	}
+	center -= .5
+	argument := math.Min(1, math.Abs(scale))
+	support := draw.CatmullRom.Support / argument
+	start := int(max(float64(source), math.Floor(center-support)))
+	stop := int(min(float64(limit), math.Ceil(center+support)))
+	weight := func(x int) float64 {
+		distance := math.Abs((float64(x) - center) * argument)
+		if distance < draw.CatmullRom.Support {
+			return draw.CatmullRom.At(distance)
+		}
+		return 0
+	}
+	var total float64
+	for x := start; x < stop; x++ {
+		total += weight(x)
+	}
+	return start, stop, func(x int) float64 { return weight(x) / total }
+}
+
+// drawRasterFootprintImage 在细轴权重超预算时按原累加顺序逐点绘制
+// 入参: dst 目标图像, src 源图像, m 像素变换, op 合成操作, target 目标范围
+// 返回: bool 是否完成绘制
+func drawRasterFootprintImage(dst draw.Image, src image.Image, m [6]float64, op draw.Op, target image.Rectangle) bool {
+	pixels, ok := src.(image.RGBA64Image)
+	if !ok {
+		pixels = rasterImageSource{src}
+	}
+	b := src.Bounds()
+	output := image.NewRGBA64(image.Rect(0, 0, 1, 1))
+	var value [1]rasterImagePixel
+	for y := target.Min.Y; y < target.Max.Y; y++ {
+		firstY, endY, wy := rasterImageWeightSpan(y, b.Min.Y, b.Max.Y, m[3], m[5])
+		if firstY == endY {
+			continue
+		}
+		for x := target.Min.X; x < target.Max.X; x++ {
+			firstX, endX, wx := rasterImageWeightSpan(x, b.Min.X, b.Max.X, m[0], m[4])
+			if firstX == endX {
+				continue
+			}
+			value[0] = rasterImagePixel{}
+			for sy := firstY; sy < endY; sy++ {
+				var row rasterImagePixel
+				for sx := firstX; sx < endX; sx++ {
+					p, weight := pixels.RGBA64At(sx, sy), wx(sx)
+					if weight != 0 {
+						row.r += float64(p.R) * weight
+						row.g += float64(p.G) * weight
+						row.b += float64(p.B) * weight
+						row.a += float64(p.A) * weight
+					}
+				}
+				if weight := wy(sy); weight != 0 {
+					value[0].r += row.r * weight
+					value[0].g += row.g * weight
+					value[0].b += row.b * weight
+					value[0].a += row.a * weight
+				}
+			}
+			rasterImageWriteRow(dst, output, value[:], x, y, op)
+		}
+	}
+	return true
+}
+
+// rasterImageFootprintAxis 对不足一个目标像素的整轴保留真实交叠面积及预乘透明度
+// 入参: first 目标起点, end 目标终点, source 源起点, limit 源终点, scale 缩放比例, offset 平移距离
+// 返回: []rasterAxisSample 轴向覆盖权重
+func rasterImageFootprintAxis(first, end, source, limit int, scale, offset float64) []rasterAxisSample {
+	lo, hi := float64(source)*scale+offset, float64(limit)*scale+offset
+	if hi < lo {
+		lo, hi = hi, lo
+	}
+	result := make([]rasterAxisSample, 0, min(2, end-first))
+	for pixel := first; pixel < end; pixel++ {
+		if math.Min(float64(pixel+1), hi) > math.Max(float64(pixel), lo) {
+			result = append(result, rasterAxisSample{pixel: pixel, first: source})
+		}
+	}
+	buffer := make([]float64, len(result)*(limit-source))
+	for index := range result {
+		sample := &result[index]
+		left, right := (float64(sample.pixel)-offset)/scale, (float64(sample.pixel+1)-offset)/scale
+		if right < left {
+			left, right = right, left
+		}
+		n := limit - source
+		sample.weights, buffer = buffer[:n:n], buffer[n:]
+		for i := range sample.weights {
+			x := float64(source + i)
+			sample.weights[i] = math.Max(0, math.Min(x+1, right)-math.Max(x, left)) * math.Abs(scale)
+		}
+	}
+	return result
+}
+
+// rasterImageHorizontal 按源列复用像素，保留各目标像素的权重累加顺序与中间精度
+// 入参: row 横向缓冲, src 源像素, samples 采样表, y 源行坐标
+func rasterImageHorizontal(row []rasterImagePixel, src image.RGBA64Image, samples []rasterAxisSample, y int) {
+	clear(row)
+	first, last := samples[0], samples[len(samples)-1]
+	reversed := first.first > last.first || first.first == last.first && len(first.weights) > len(last.weights)
+	start := min(first.first, last.first)
+	end := max(first.first+len(first.weights), last.first+len(last.weights))
+	active, next := 0, 0
+	for x := start; x < end; x++ {
+		for next < len(samples) {
+			index := next
+			if reversed {
+				index = len(samples) - next - 1
+			}
+			if samples[index].first > x {
+				break
+			}
+			next++
+		}
+		for active < next {
+			index := active
+			if reversed {
+				index = len(samples) - active - 1
+			}
+			if x < samples[index].first+len(samples[index].weights) {
+				break
+			}
+			active++
+		}
+		p := src.RGBA64At(x, y)
+		r, g, b, a := float64(p.R), float64(p.G), float64(p.B), float64(p.A)
+		for column := active; column < next; column++ {
+			index := column
+			if reversed {
+				index = len(samples) - column - 1
+			}
+			sample := samples[index]
+			weight := sample.weights[x-sample.first]
+			if weight != 0 {
+				value := &row[index]
+				value.r += r * weight
+				value.g += g * weight
+				value.b += b * weight
+				value.a += a * weight
+			}
+		}
+	}
+}
+
+// rasterImageWriteRow 在两轴采样完成后取整并使用标准预乘合成
+// 入参: dst 目标图像, output 行像素缓冲, values 累积颜色, x 横向起点, y 目标行坐标, op 合成操作
+func rasterImageWriteRow(dst draw.Image, output *image.RGBA64, values []rasterImagePixel, x, y int, op draw.Op) {
+	for i, value := range values {
+		r := rasterImageComponent(value.r, value.a)
+		g := rasterImageComponent(value.g, value.a)
+		b := rasterImageComponent(value.b, value.a)
+		a := rasterImageComponent(value.a, value.a)
+		pixel := output.Pix[i*8 : i*8+8 : i*8+8]
+		pixel[0], pixel[1] = uint8(r>>8), uint8(r)
+		pixel[2], pixel[3] = uint8(g>>8), uint8(g)
+		pixel[4], pixel[5] = uint8(b>>8), uint8(b)
+		pixel[6], pixel[7] = uint8(a>>8), uint8(a)
+	}
+	draw.Draw(dst, image.Rect(x, y, x+len(values), y+1), output, image.Point{}, op)
+}
+
+// rasterImageComponent 按预乘透明度裁切并取整十六位分量
+// 入参: value 采样分量, alpha 采样透明度
+// 返回: uint16 输出分量
+func rasterImageComponent(value, alpha float64) uint16 {
+	if value > alpha || math.IsNaN(alpha) {
+		value = alpha
+	}
+	value += .5
+	if value <= 0 {
+		return 0
+	}
+	if value >= 65535 {
+		return 65535
+	}
+	return uint16(value)
+}
+
+// DrawPixels 对轴向缩放使用可分离采样，其余变换保留通用路径
+// 入参: dst 目标图像, src 源图像, m 按a、b、c、d、e、f排列的像素变换, op 合成操作
+func DrawPixels(dst draw.Image, src image.Image, m [6]float64, op draw.Op) {
+	b := src.Bounds()
+	if dr, ok := rasterScaleBounds(b, m); ok {
+		if dr.Intersect(dst.Bounds()).Empty() {
+			return
+		}
+		draw.CatmullRom.Scale(dst, dr, src, b, op, nil)
+		return
+	}
+	if drawRasterAxisImage(dst, src, m, op) {
+		return
+	}
+	src = rasterTransformSource(src, TransformBounds(b, m, dst.Bounds()))
+	draw.CatmullRom.Transform(dst, f64.Aff3{m[0], m[2], m[4], m[1], m[3], m[5]}, src, b, op, nil)
+}
+
+// rasterTransformSource 为放大的通用图像缓存十六位预乘像素，限制临时缓冲大小
+// 入参: src 源图像, affected 目标采样区域
+// 返回: image.Image 等值采样图像
+func rasterTransformSource(src image.Image, affected image.Rectangle) image.Image {
+	switch src.(type) {
+	case *image.RGBA, *image.RGBA64:
+		return src
+	}
+	b := src.Bounds()
+	if b.Empty() || affected.Empty() || b.Dx() > rasterScaleBufferLimit/8/b.Dy() || float64(affected.Dx())*float64(affected.Dy()) < float64(b.Dx())*float64(b.Dy()) {
+		return src
+	}
+	pixels := image.NewRGBA64(b)
+	draw.Draw(pixels, b, src, b.Min, draw.Src)
+	return pixels
+}
+
+// rasterScaleBounds 检查变换是否可无几何取整地使用缩放器，并限制其中间缓冲
+// 入参: b 源边界, m 像素变换
+// 返回: image.Rectangle 缩放边界, bool 是否适用
+func rasterScaleBounds(b image.Rectangle, m [6]float64) (image.Rectangle, bool) {
+	if b.Empty() || m[1] != 0 || m[2] != 0 || m[0] <= 0 || m[0] > 1 || m[3] <= 0 || m[3] > 1 || m[0] == 1 && m[3] == 1 {
+		return image.Rectangle{}, false
+	}
+	x0, y0 := float64(m[0]*float64(b.Min.X))+m[4], float64(m[3]*float64(b.Min.Y))+m[5]
+	x1, y1 := float64(m[0]*float64(b.Max.X))+m[4], float64(m[3]*float64(b.Max.Y))+m[5]
+	for _, v := range [4]float64{x0, y0, x1, y1} {
+		if v != math.Floor(v) || v < math.MinInt32 || v > math.MaxInt32 {
+			return image.Rectangle{}, false
+		}
+	}
+	if x1 <= x0 || y1 <= y0 || b.Dx() > math.MaxInt32 || b.Dy() > math.MaxInt32 || (x1-x0)*float64(b.Dy()) > rasterScaleBufferLimit/32 {
+		return image.Rectangle{}, false
+	}
+	return image.Rect(int(x0), int(y0), int(x1), int(y1)), true
+}
+
+// TransformBounds 计算采样器可能写入的像素范围，并在整数转换前裁至目标边界
+// 入参: source 原始像素边界, m 像素变换, target 目标边界
+// 返回: image.Rectangle 受影响的目标像素区域
+func TransformBounds(source image.Rectangle, m [6]float64, target image.Rectangle) image.Rectangle {
+	minX, minY, maxX, maxY := math.Inf(1), math.Inf(1), math.Inf(-1), math.Inf(-1)
+	for _, p := range [4]image.Point{source.Min, {X: source.Max.X, Y: source.Min.Y}, {X: source.Min.X, Y: source.Max.Y}, source.Max} {
+		x := math.Floor(float64(m[0]*float64(p.X)) + float64(m[2]*float64(p.Y)) + m[4])
+		y := math.Floor(float64(m[1]*float64(p.X)) + float64(m[3]*float64(p.Y)) + m[5])
+		minX, minY = math.Min(minX, x), math.Min(minY, y)
+		maxX, maxY = math.Max(maxX, x+1), math.Max(maxY, y+1)
+	}
+	minX, minY = math.Max(minX, float64(target.Min.X)), math.Max(minY, float64(target.Min.Y))
+	maxX, maxY = math.Min(maxX, float64(target.Max.X)), math.Min(maxY, float64(target.Max.Y))
+	if minX >= maxX || minY >= maxY {
+		return image.Rectangle{}
+	}
+	return image.Rect(int(minX), int(minY), int(maxX), int(maxY))
+}

internal/base/image/storage.go

@@ -0,0 +1,148 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package image
+
+import (
+	"image"
+	"image/color"
+)
+
+// StorageCost 预留十六位像素空间，并计入编码、调色板与底层像素缓冲容量
+// 包装图像可实现BackingImage() image.Image，使底层共享缓冲计入预算
+// 入参: img 图片资源, limit 缓存预算
+// 返回: int 估算字节数或超预算标记
+func StorageCost(img image.Image, limit int) int {
+	cost := 256
+	w, h := img.Bounds().Dx(), img.Bounds().Dy()
+	if limit < cost || w <= 0 || h <= 0 || w > (limit-cost)/8/h {
+		return limit + 1
+	}
+	pixels := w * h * 8
+	if encoded, ok := img.(*EncodedImage); ok {
+		if encoded.pngColor != nil {
+			if limit-cost < 512 {
+				return limit + 1
+			}
+			cost += 512
+		}
+		if cap(encoded.profile) > limit-cost {
+			return limit + 1
+		}
+		cost += cap(encoded.profile)
+		if encoded.profile != nil || encoded.pngColor != nil || encoded.config.ColorModel == color.CMYKModel {
+			pixelSize := 12
+			if encoded.config.ColorModel == color.RGBA64Model || encoded.config.ColorModel == color.NRGBA64Model {
+				pixelSize = 16
+			}
+			if w > (limit-cost)/pixelSize/h {
+				return limit + 1
+			}
+			pixels = w * h * pixelSize
+		}
+		if result := encoded.result.Load(); result != nil && result.image != nil {
+			pixels = max(pixels, StorageCost(result.image, limit-cost))
+		}
+		if cap(encoded.data) > limit-cost-pixels {
+			return limit + 1
+		}
+		return cost + pixels + cap(encoded.data)
+	}
+	var buffers [5]int
+	switch source := img.(type) {
+	case *colorImage:
+		buffers[0] = cap(source.Pix)
+		buffers[1] = StorageCost(source.source, limit-cost)
+	case *image.RGBA:
+		buffers[0] = cap(source.Pix)
+	case *image.RGBA64:
+		buffers[0] = cap(source.Pix)
+	case *image.NRGBA:
+		buffers[0] = cap(source.Pix)
+	case *image.NRGBA64:
+		buffers[0] = cap(source.Pix)
+	case *image.Gray:
+		buffers[0] = cap(source.Pix)
+	case *image.Gray16:
+		buffers[0] = cap(source.Pix)
+	case *image.Alpha:
+		buffers[0] = cap(source.Pix)
+	case *image.Alpha16:
+		buffers[0] = cap(source.Pix)
+	case *image.CMYK:
+		buffers[0] = cap(source.Pix)
+	case *image.Paletted:
+		if cap(source.Palette) > (limit-cost)/16 {
+			return limit + 1
+		}
+		buffers[0], buffers[1] = cap(source.Pix), cap(source.Palette)*16
+	case *image.YCbCr:
+		buffers = [5]int{cap(source.Y), cap(source.Cb), cap(source.Cr)}
+	case *image.NYCbCrA:
+		buffers = [5]int{cap(source.Y), cap(source.Cb), cap(source.Cr), cap(source.A)}
+	case *planarTIFFImage:
+		if cap(source.palette) > (limit-cost)/8 {
+			return limit + 1
+		}
+		cost += cap(source.palette) * 8
+		if cap(source.planes) > (limit-cost)/16 || len(source.planes) > len(buffers) {
+			return limit + 1
+		}
+		cost += cap(source.planes) * 16
+		for i, plane := range source.planes {
+			switch plane := plane.(type) {
+			case *image.Gray:
+				buffers[i] = cap(plane.Pix)
+			case *image.Gray16:
+				buffers[i] = cap(plane.Pix)
+			default:
+				buffers[i] = StorageCost(plane, limit-cost)
+			}
+		}
+	case *tiffFaxImage:
+		if cap(source.blocks) > (limit-cost)/16 {
+			return limit + 1
+		}
+		cost += cap(source.blocks) * 16
+		for _, block := range source.blocks {
+			size := StorageCost(block, limit-cost)
+			if size > limit-cost {
+				return limit + 1
+			}
+			cost += size
+		}
+	case *orientedTIFFImage:
+		buffers[0] = StorageCost(source.source, limit-cost)
+	case *maskedTIFFImage:
+		buffers[0] = StorageCost(source.source, limit-cost)
+		buffers[1] = StorageCost(source.mask, limit-cost)
+	case *transparentEdgeImage:
+		buffers[0] = StorageCost(source.source, limit-cost)
+	case *transparentEdgeImage64:
+		buffers[0] = StorageCost(source.source, limit-cost)
+	case interface{ BackingImage() image.Image }:
+		buffers[0] = StorageCost(source.BackingImage(), limit-cost)
+	}
+	storage := 0
+	for _, size := range buffers {
+		if size > limit-cost-storage {
+			return limit + 1
+		}
+		storage += size
+	}
+	if pixels > limit-cost {
+		return limit + 1
+	}
+	return cost + max(pixels, storage)
+}

internal/base/image/tiff.go

@@ -0,0 +1,433 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package image
+
+import (
+	"bytes"
+	"context"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"image"
+	"image/color"
+	"io"
+)
+
+// ErrTIFFRandomAccess 表示目录链需要回读，仅流式输入需重新打开资源
+var ErrTIFFRandomAccess = errors.New("TIFF directory requires random access")
+
+// TIFFLayout 保存TIFF目录的图像布局及关联透明蒙版
+type TIFFLayout struct {
+	Width, Height int
+	TileWidth     int
+	TileHeight    int
+	Orientation   int
+	Offset, Next  uint32
+	Reduced, mask bool
+	Planar        bool
+	auxiliary     bool
+	Samples       uint32
+	depth         uint32
+	fillOrder     uint32
+	compression   uint32
+	predictor     uint32
+	photometric   uint32
+	profileOffset uint32
+	profileSize   uint32
+	t4, t6        uint32
+	Transparency  *TIFFLayout
+}
+
+// tiffDirectoryInput 只替换解码视图中的首目录偏移，不复制或改写原始资源
+type tiffDirectoryInput struct {
+	reader    *bytes.Reader
+	directory [4]byte
+	ctx       context.Context
+}
+
+// orientedTIFFImage 按方向映射像素坐标，复用原图数据与颜色精度
+type orientedTIFFImage struct {
+	source image.Image
+	TIFFLayout
+}
+
+// IsTIFF 识别标准TIFF字节序与版本标识
+// 入参: data 文件头或完整编码
+// 返回: bool 是否为TIFF 6.0编码
+func IsTIFF(data []byte) bool {
+	return len(data) >= 4 && (string(data[:4]) == "II\x2a\x00" || string(data[:4]) == "MM\x00\x2a")
+}
+
+// readTIFFLayout 选择主图及其蒙版，允许缩略图并拒绝循环和多个主图
+// 入参: input 从文件头开始的输入流
+// 返回: TIFFLayout 存储尺寸与方向, error 文件结构或方向错误
+func readTIFFLayout(input io.Reader) (TIFFLayout, error) {
+	return ReadTIFFLayoutContext(context.Background(), input)
+}
+
+// ReadTIFFLayoutContext 扫描目录链并选择主图，读取期间响应取消
+// 入参: ctx 取消上下文, input 从文件头开始的输入流
+// 返回: TIFFLayout 存储尺寸与方向, error 结构、读取或取消错误
+func ReadTIFFLayoutContext(ctx context.Context, input io.Reader) (TIFFLayout, error) {
+	var result TIFFLayout
+	if err := ctx.Err(); err != nil {
+		return result, err
+	}
+	var header [8]byte
+	if _, err := io.ReadFull(input, header[:]); err != nil {
+		return result, err
+	}
+	if !IsTIFF(header[:]) {
+		return result, fmt.Errorf("invalid TIFF header")
+	}
+	var order binary.ByteOrder = binary.LittleEndian
+	if header[0] == 'M' {
+		order = binary.BigEndian
+	}
+	offset := int64(order.Uint32(header[4:]))
+	position := int64(8)
+	var seen map[uint32]bool
+	var transparency *TIFFLayout
+	for offset != 0 {
+		if seen != nil && seen[uint32(offset)] {
+			return result, fmt.Errorf("cyclic TIFF directory chain")
+		}
+		layout, end, err := readTIFFDirectory(ctx, input, order, offset, position)
+		if err != nil {
+			return result, err
+		}
+		if layout.mask {
+			if !layout.Reduced {
+				if transparency != nil {
+					return result, fmt.Errorf("multiple TIFF transparency masks")
+				}
+				transparency = &layout
+			}
+		} else if !layout.Reduced || layout.Next == 0 && seen == nil {
+			if result.Offset != 0 {
+				return result, fmt.Errorf("multiple TIFF pages are not supported in OFD resources")
+			}
+			result = layout
+		}
+		if layout.Next != 0 {
+			if seen == nil {
+				seen = make(map[uint32]bool)
+			}
+			seen[uint32(offset)] = true
+		}
+		offset, position = int64(layout.Next), end
+	}
+	if err := ctx.Err(); err != nil {
+		return TIFFLayout{}, err
+	}
+	if result.Offset == 0 {
+		return result, fmt.Errorf("missing TIFF main image")
+	}
+	result.Transparency = transparency
+	if transparency != nil {
+		size := result.DisplaySize()
+		if size.X > int(^uint(0)>>1)/8/size.Y {
+			return TIFFLayout{}, fmt.Errorf("TIFF mask image dimensions exceed capacity")
+		}
+	}
+	return result, nil
+}
+
+// readTIFFDirectory 读取目录中的图像布局和子文件类型，不读取像素
+// 入参: ctx 取消上下文, input 输入流, order 字节序, offset 目录偏移, position 当前流位置
+// 返回: TIFFLayout 目录布局, int64 读取后的流位置, error 结构、读取或取消错误
+func readTIFFDirectory(ctx context.Context, input io.Reader, order binary.ByteOrder, offset, position int64) (TIFFLayout, int64, error) {
+	var result TIFFLayout
+	if err := ctx.Err(); err != nil {
+		return result, position, err
+	}
+	var header [4]byte
+	if offset < 8 {
+		return result, position, fmt.Errorf("invalid TIFF directory offset")
+	}
+	if seeker, ok := input.(io.Seeker); ok {
+		if _, err := seeker.Seek(offset, io.SeekStart); err != nil {
+			return result, position, err
+		}
+	} else {
+		if offset < position {
+			return result, position, ErrTIFFRandomAccess
+		}
+		reader := contextInput{ReadCloser: io.NopCloser(input), ctx: ctx}
+		if _, err := io.CopyN(io.Discard, reader, offset-position); err != nil {
+			return result, position, err
+		}
+	}
+	if _, err := io.ReadFull(input, header[:2]); err != nil {
+		return result, position, err
+	}
+	count := int(order.Uint16(header[:2]))
+	result.Orientation, result.Offset, result.Samples, result.fillOrder = 1, uint32(offset), 1, 1
+	result.depth = 1
+	result.compression = 1
+	result.predictor = 1
+	var entry [12]byte
+	var previous uint16
+	var subfile, legacy uint32
+	var hasSubfile bool
+	var invalidMaskDepth bool
+	for i := range count {
+		if err := ctx.Err(); err != nil {
+			return result, position, err
+		}
+		if _, err := io.ReadFull(input, entry[:]); err != nil {
+			return result, position, err
+		}
+		tag, kind, number := order.Uint16(entry[:2]), order.Uint16(entry[2:4]), order.Uint32(entry[4:8])
+		if i > 0 && tag <= previous {
+			return result, position, fmt.Errorf("invalid TIFF directory order")
+		}
+		previous = tag
+		if tag == 338 {
+			result.auxiliary = kind != 3 || number != 1 || order.Uint16(entry[8:]) == 0
+		}
+		if tag == 34675 {
+			if kind != 7 || number < 132 {
+				return result, position, fmt.Errorf("invalid TIFF color profile")
+			}
+			result.profileOffset, result.profileSize = order.Uint32(entry[8:]), number
+			continue
+		}
+		if tag == 258 {
+			invalidMaskDepth = kind != 3 || number != 1
+			if !invalidMaskDepth {
+				result.depth = uint32(order.Uint16(entry[8:10]))
+			}
+		}
+		if tag != 254 && tag != 255 && tag != 256 && tag != 257 && tag != 259 && tag != 262 && tag != 266 && tag != 274 && tag != 277 && tag != 284 && tag != 292 && tag != 293 && tag != 317 && tag != 322 && tag != 323 {
+			continue
+		}
+		if number != 1 || kind != 3 && kind != 4 || (tag == 255 || tag == 259 || tag == 262 || tag == 266 || tag == 274 || tag == 277 || tag == 284 || tag == 317) && kind != 3 || (tag == 254 || tag == 292 || tag == 293) && kind != 4 {
+			return result, position, fmt.Errorf("invalid TIFF image layout")
+		}
+		value := uint64(order.Uint32(entry[8:12]))
+		if kind == 3 {
+			value = uint64(order.Uint16(entry[8:10]))
+		}
+		if (tag == 256 || tag == 257 || tag == 322 || tag == 323) && (value == 0 || value > uint64(int(^uint(0)>>1))) {
+			return result, position, fmt.Errorf("invalid TIFF dimensions")
+		}
+		switch tag {
+		case 254:
+			subfile, hasSubfile = uint32(value), true
+		case 255:
+			legacy = uint32(value)
+		case 256:
+			result.Width = int(value)
+		case 257:
+			result.Height = int(value)
+		case 259:
+			result.compression = uint32(value)
+		case 262:
+			result.photometric = uint32(value)
+			result.mask = value == 4
+		case 266:
+			if value != 1 && value != 2 {
+				return result, position, fmt.Errorf("invalid TIFF fill order")
+			}
+			result.fillOrder = uint32(value)
+		case 274:
+			if value < 1 || value > 8 {
+				return result, position, fmt.Errorf("invalid TIFF orientation")
+			}
+			result.Orientation = int(value)
+		case 277:
+			if value == 0 {
+				return result, position, fmt.Errorf("invalid TIFF sample count")
+			}
+			result.Samples = uint32(value)
+		case 284:
+			if value != 1 && value != 2 {
+				return result, position, fmt.Errorf("invalid TIFF planar configuration")
+			}
+			result.Planar = value == 2
+		case 292:
+			result.t4 = uint32(value)
+		case 293:
+			result.t6 = uint32(value)
+		case 317:
+			result.predictor = uint32(value)
+		case 322:
+			result.TileWidth = int(value)
+		case 323:
+			result.TileHeight = int(value)
+		}
+	}
+	if _, err := io.ReadFull(input, header[:4]); err != nil {
+		return result, position, err
+	}
+	result.Next = order.Uint32(header[:4])
+	if hasSubfile {
+		result.Reduced, result.mask = subfile&1 != 0, result.mask || subfile&4 != 0
+	} else {
+		result.Reduced = legacy == 2
+	}
+	if result.Width == 0 || result.Height == 0 {
+		return result, position, fmt.Errorf("missing TIFF dimensions")
+	}
+	if (result.TileWidth == 0) != (result.TileHeight == 0) || result.TileWidth%16 != 0 || result.TileHeight%16 != 0 {
+		return result, position, fmt.Errorf("invalid TIFF tile dimensions")
+	}
+	if result.mask && (invalidMaskDepth || result.photometric != 4 || result.Samples != 1 || result.depth != 1) {
+		return result, position, fmt.Errorf("invalid TIFF transparency mask")
+	}
+	return result, offset + 6 + int64(count)*12, nil
+}
+
+// newTIFFDirectoryInput 创建以指定目录作为主图的只读解码视图
+// 入参: data 已校验的TIFF编码, offset 主图目录偏移
+// 返回: *tiffDirectoryInput 随机访问输入
+func newTIFFDirectoryInput(data []byte, offset uint32) *tiffDirectoryInput {
+	input := &tiffDirectoryInput{reader: bytes.NewReader(data)}
+	var order binary.ByteOrder = binary.LittleEndian
+	if data[0] == 'M' {
+		order = binary.BigEndian
+	}
+	order.PutUint32(input.directory[:], offset)
+	return input
+}
+
+// patch 替换读取片段中与首目录指针重叠的部分
+// 入参: data 读取结果, offset 文件偏移
+func (r *tiffDirectoryInput) patch(data []byte, offset int64) {
+	for i := range r.directory {
+		at := int64(4+i) - offset
+		if at >= 0 && at < int64(len(data)) {
+			data[at] = r.directory[i]
+		}
+	}
+}
+
+// Read 读取图像编码并覆盖首目录指针
+// 入参: data 接收缓冲
+// 返回: int 读取字节数, error 读取错误
+func (r *tiffDirectoryInput) Read(data []byte) (int, error) {
+	if r.ctx != nil {
+		if err := r.ctx.Err(); err != nil {
+			return 0, err
+		}
+	}
+	offset := r.reader.Size() - int64(r.reader.Len())
+	n, err := r.reader.Read(data)
+	r.patch(data[:n], offset)
+	return n, err
+}
+
+// ReadAt 随机读取图像编码并覆盖首目录指针
+// 入参: data 接收缓冲, offset 文件偏移
+// 返回: int 读取字节数, error 读取错误
+func (r *tiffDirectoryInput) ReadAt(data []byte, offset int64) (int, error) {
+	if r.ctx != nil {
+		if err := r.ctx.Err(); err != nil {
+			return 0, err
+		}
+	}
+	n, err := r.reader.ReadAt(data, offset)
+	r.patch(data[:n], offset)
+	return n, err
+}
+
+// size 返回应用方向后的显示尺寸
+// 返回: image.Point 像素宽高
+func (l TIFFLayout) size() image.Point {
+	if l.Orientation >= 5 {
+		return image.Pt(l.Height, l.Width)
+	}
+	return image.Pt(l.Width, l.Height)
+}
+
+// DisplaySize 返回同时保留主图和透明蒙版分辨率的显示尺寸
+// 返回: image.Point 保留高分辨率蒙版边缘的像素宽高
+func (l TIFFLayout) DisplaySize() image.Point {
+	size := l.size()
+	if l.Transparency != nil {
+		mask := l.Transparency.size()
+		size.X, size.Y = max(size.X, mask.X), max(size.Y, mask.Y)
+	}
+	return size
+}
+
+// Bounds 返回从零开始的显示区域
+// 返回: image.Rectangle 显示区域
+func (s *orientedTIFFImage) Bounds() image.Rectangle {
+	return image.Rectangle{Max: s.size()}
+}
+
+// ColorModel 返回原始颜色模型
+// 返回: color.Model 颜色模型
+func (s *orientedTIFFImage) ColorModel() color.Model { return s.source.ColorModel() }
+
+// sourcePoint 将显示坐标映射为存储坐标
+// 入参: x 横向显示坐标, y 纵向显示坐标
+// 返回: image.Point 原始坐标, bool 是否位于显示区域内
+func (s *orientedTIFFImage) sourcePoint(x, y int) (image.Point, bool) {
+	if !image.Pt(x, y).In(s.Bounds()) {
+		return image.Point{}, false
+	}
+	w, h := s.Width, s.Height
+	switch s.Orientation {
+	case 2:
+		x = w - 1 - x
+	case 3:
+		x, y = w-1-x, h-1-y
+	case 4:
+		y = h - 1 - y
+	case 5:
+		x, y = y, x
+	case 6:
+		x, y = y, h-1-x
+	case 7:
+		x, y = w-1-y, h-1-x
+	case 8:
+		x, y = w-1-y, x
+	}
+	b := s.source.Bounds()
+	return image.Pt(b.Min.X+x, b.Min.Y+y), true
+}
+
+// At 返回原图颜色，不重新采样或量化
+// 入参: x 横向显示坐标, y 纵向显示坐标
+// 返回: color.Color 像素颜色，区域外透明
+func (s *orientedTIFFImage) At(x, y int) color.Color {
+	p, ok := s.sourcePoint(x, y)
+	if !ok {
+		return color.NRGBA64{}
+	}
+	return s.source.At(p.X, p.Y)
+}
+
+// NRGBA64At 读取非预乘十六位颜色，保留透明像素中的原始颜色
+// 入参: x 横向显示坐标, y 纵向显示坐标
+// 返回: color.NRGBA64 像素颜色
+func (s *orientedTIFFImage) NRGBA64At(x, y int) color.NRGBA64 {
+	p, ok := s.sourcePoint(x, y)
+	if !ok {
+		return color.NRGBA64{}
+	}
+	return NRGBA64At(s.source, p.X, p.Y)
+}
+
+// RGBA64At 返回预乘十六位像素，保留原始颜色精度
+// 入参: x 横向显示坐标, y 纵向显示坐标
+// 返回: color.RGBA64 像素颜色
+func (s *orientedTIFFImage) RGBA64At(x, y int) color.RGBA64 {
+	r, g, b, a := s.At(x, y).RGBA()
+	return color.RGBA64{R: uint16(r), G: uint16(g), B: uint16(b), A: uint16(a)}
+}

internal/base/image/tiff_bits.go

@@ -0,0 +1,189 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package image
+
+import (
+	"cmp"
+	"context"
+	"encoding/binary"
+	"fmt"
+	"image"
+	"io"
+	"math/bits"
+	"slices"
+	"sort"
+
+	"golang.org/x/image/tiff"
+)
+
+// tiffBitOrderInput 仅在读取像素块时反转字节内位序，保留目录和原始数据
+type tiffBitOrderInput struct {
+	source   io.ReaderAt
+	ranges   [][2]int64
+	position int64
+}
+
+// tiffBitOrderRanges 收集低位优先的未压缩一位图像块，压缩传真位序由解码器处理
+// 入参: ctx 取消上下文，可为nil, data TIFF编码, layout 已校验的主图布局
+// 返回: [][2]int64 按偏移排序且不重叠的字节区间, error 字段或布局错误
+func tiffBitOrderRanges(ctx context.Context, data []byte, layout TIFFLayout) ([][2]int64, error) {
+	if layout.fillOrder != 2 {
+		return nil, nil
+	}
+	var order binary.ByteOrder = binary.LittleEndian
+	if data[0] == 'M' {
+		order = binary.BigEndian
+	}
+	offset := int(layout.Offset)
+	count := int(order.Uint16(data[offset:]))
+	entries := make(map[uint16][]byte, count)
+	for i := range count {
+		entry := data[offset+2+i*12 : offset+14+i*12]
+		entries[order.Uint16(entry)] = entry
+	}
+	compression := entries[259]
+	method := uint16(1)
+	if compression != nil {
+		if order.Uint16(compression[2:]) != 3 || order.Uint32(compression[4:]) != 1 {
+			return nil, fmt.Errorf("invalid TIFF compression field")
+		}
+		method = order.Uint16(compression[8:])
+	}
+	if method == 3 || method == 4 {
+		return nil, nil
+	}
+	if method != 1 {
+		return nil, fmt.Errorf("unsupported TIFF fill order for compression %d", method)
+	}
+	if entry := entries[258]; entry != nil {
+		if order.Uint16(entry[2:]) != 3 || order.Uint32(entry[4:]) != layout.Samples {
+			return nil, fmt.Errorf("invalid TIFF sample depths")
+		}
+		for i := uint32(0); i < layout.Samples; i++ {
+			depth, err := tiffPlaneValue(data, order, entry, i)
+			if err != nil || depth != 1 {
+				return nil, fmt.Errorf("unsupported TIFF fill order for sample depth")
+			}
+		}
+	}
+	locations, lengths := entries[273], entries[279]
+	value := func(tag uint16, fallback uint32) (uint32, error) {
+		entry := entries[tag]
+		if entry == nil {
+			return fallback, nil
+		}
+		if order.Uint32(entry[4:]) != 1 {
+			return 0, fmt.Errorf("invalid TIFF scalar field %d", tag)
+		}
+		return tiffPlaneValue(data, order, entry, 0)
+	}
+	rows, err := value(278, ^uint32(0))
+	if err != nil || rows == 0 {
+		return nil, fmt.Errorf("invalid TIFF rows per strip")
+	}
+	expected := (uint64(layout.Height)-1)/uint64(rows) + 1
+	if entries[322] != nil {
+		locations, lengths = entries[324], entries[325]
+		width, err := value(322, 0)
+		if err != nil || width == 0 || width%16 != 0 {
+			return nil, fmt.Errorf("invalid TIFF tile width")
+		}
+		height, err := value(323, 0)
+		if err != nil || height == 0 || height%16 != 0 {
+			return nil, fmt.Errorf("invalid TIFF tile height")
+		}
+		expected = ((uint64(layout.Width)-1)/uint64(width) + 1) * ((uint64(layout.Height)-1)/uint64(height) + 1)
+		if locations != nil && order.Uint16(locations[2:]) != 4 {
+			return nil, fmt.Errorf("invalid TIFF tile offsets")
+		}
+	}
+	if layout.Planar {
+		if expected > uint64(^uint32(0))/uint64(layout.Samples) {
+			return nil, fmt.Errorf("too many TIFF image blocks")
+		}
+		expected *= uint64(layout.Samples)
+	}
+	if locations == nil || lengths == nil {
+		return nil, fmt.Errorf("missing TIFF block arrays")
+	}
+	blocks := order.Uint32(locations[4:])
+	if blocks == 0 || uint64(blocks) != expected || order.Uint32(lengths[4:]) != blocks {
+		return nil, fmt.Errorf("invalid TIFF block count")
+	}
+	var ranges [][2]int64
+	for i := uint32(0); i < blocks; i++ {
+		if ctx != nil {
+			if err := ctx.Err(); err != nil {
+				return nil, err
+			}
+		}
+		at, err := tiffPlaneValue(data, order, locations, i)
+		if err != nil {
+			return nil, err
+		}
+		size, err := tiffPlaneValue(data, order, lengths, i)
+		if err != nil || size == 0 || uint64(at)+uint64(size) > uint64(len(data)) {
+			return nil, fmt.Errorf("truncated TIFF image block")
+		}
+		ranges = append(ranges, [2]int64{int64(at), int64(at) + int64(size)})
+	}
+	slices.SortFunc(ranges, func(a, b [2]int64) int { return cmp.Compare(a[0], b[0]) })
+	merged := ranges[:0]
+	for _, span := range ranges {
+		if len(merged) != 0 && span[0] <= merged[len(merged)-1][1] {
+			merged[len(merged)-1][1] = max(merged[len(merged)-1][1], span[1])
+		} else {
+			merged = append(merged, span)
+		}
+	}
+	return merged, nil
+}
+
+// decodeTIFFBitOrder 使用只读视图校正位序，不分配整幅编码的副本
+// 入参: input 原始解码视图, ranges 需要反转位序的像素区间
+// 返回: image.Image 解码图像, error 解码错误
+func decodeTIFFBitOrder(input interface {
+	io.Reader
+	io.ReaderAt
+}, ranges [][2]int64) (image.Image, error) {
+	if len(ranges) == 0 {
+		return tiff.Decode(input)
+	}
+	return tiff.Decode(&tiffBitOrderInput{source: input, ranges: ranges})
+}
+
+// Read 顺序读取并校正像素字节的位序
+// 入参: data 接收缓冲
+// 返回: int 读取字节数, error 读取错误
+func (r *tiffBitOrderInput) Read(data []byte) (int, error) {
+	n, err := r.ReadAt(data, r.position)
+	r.position += int64(n)
+	return n, err
+}
+
+// ReadAt 按文件偏移读取，只反转实际读取到的像素字节
+// 入参: data 接收缓冲, offset 文件偏移
+// 返回: int 读取字节数, error 读取错误
+func (r *tiffBitOrderInput) ReadAt(data []byte, offset int64) (int, error) {
+	n, err := r.source.ReadAt(data, offset)
+	index := sort.Search(len(r.ranges), func(i int) bool { return r.ranges[i][1] > offset })
+	for ; index < len(r.ranges) && r.ranges[index][0] < offset+int64(n); index++ {
+		span := r.ranges[index]
+		for i := max(int64(0), span[0]-offset); i < min(int64(n), span[1]-offset); i++ {
+			data[i] = bits.Reverse8(data[i])
+		}
+	}
+	return n, err
+}

internal/base/image/tiff_fax.go

@@ -0,0 +1,185 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package image
+
+import (
+	"context"
+	"encoding/binary"
+	"fmt"
+	"image"
+	"image/color"
+	"math/bits"
+
+	"github.com/xiaoqidun/pdfgo"
+)
+
+// tiffFaxImage 组合独立解码的传真条带或瓦片，保留紧凑的一位像素存储
+type tiffFaxImage struct {
+	blocks []image.Image
+	bounds image.Rectangle
+	width  int
+	height int
+	across int
+}
+
+// decodeTIFFFax 按TIFF传真选项解码各图像块，复用PDFGo的T.4与T.6解码器
+// 入参: ctx 取消上下文，可为nil, data TIFF编码, layout 已校验的主图布局
+// 返回: image.Image 图像, error 字段、解码或取消错误
+func decodeTIFFFax(ctx context.Context, data []byte, layout TIFFLayout) (image.Image, error) {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	if layout.Samples != 1 || layout.compression == 3 && layout.t4 & ^uint32(7) != 0 || layout.compression == 4 && layout.t6 & ^uint32(2) != 0 {
+		return nil, fmt.Errorf("invalid TIFF fax options")
+	}
+	var order binary.ByteOrder = binary.LittleEndian
+	if data[0] == 'M' {
+		order = binary.BigEndian
+	}
+	offset := int(layout.Offset)
+	count := int(order.Uint16(data[offset:]))
+	entries := make(map[uint16][]byte, count)
+	for i := range count {
+		entry := data[offset+2+i*12 : offset+14+i*12]
+		entries[order.Uint16(entry)] = entry
+	}
+	value := func(tag uint16, fallback uint32) (uint32, error) {
+		entry := entries[tag]
+		if entry == nil {
+			return fallback, nil
+		}
+		if order.Uint32(entry[4:]) != 1 {
+			return 0, fmt.Errorf("invalid TIFF scalar field %d", tag)
+		}
+		return tiffPlaneValue(data, order, entry, 0)
+	}
+	for _, tag := range []uint16{258, 317, 339} {
+		v, err := value(tag, 1)
+		if err != nil || v != 1 || entries[tag] != nil && order.Uint16(entries[tag][2:]) != 3 {
+			return nil, fmt.Errorf("invalid TIFF fax sample field %d", tag)
+		}
+	}
+	photo, err := value(262, 2)
+	if err != nil || photo > 1 && photo != 4 || entries[338] != nil {
+		return nil, fmt.Errorf("invalid TIFF fax color model")
+	}
+	width := uint32(layout.Width)
+	height, err := value(278, ^uint32(0))
+	if err != nil || height == 0 {
+		return nil, fmt.Errorf("invalid TIFF rows per strip")
+	}
+	height = min(height, uint32(layout.Height))
+	locations, lengths := entries[273], entries[279]
+	tiled := entries[322] != nil
+	if tiled {
+		width, err = value(322, 0)
+		if err != nil || width == 0 || width%16 != 0 {
+			return nil, fmt.Errorf("invalid TIFF tile width")
+		}
+		height, err = value(323, 0)
+		if err != nil || height == 0 || height%16 != 0 {
+			return nil, fmt.Errorf("invalid TIFF tile height")
+		}
+		locations, lengths = entries[324], entries[325]
+		if locations != nil && order.Uint16(locations[2:]) != 4 {
+			return nil, fmt.Errorf("invalid TIFF tile offsets")
+		}
+	}
+	if uint64(width) > uint64(int(^uint(0)>>1)) || uint64(height) > uint64(int(^uint(0)>>1)) || locations == nil || lengths == nil {
+		return nil, fmt.Errorf("invalid TIFF fax blocks")
+	}
+	across := (uint64(layout.Width)-1)/uint64(width) + 1
+	down := (uint64(layout.Height)-1)/uint64(height) + 1
+	blocks := across * down
+	if blocks != uint64(order.Uint32(locations[4:])) || blocks != uint64(order.Uint32(lengths[4:])) {
+		return nil, fmt.Errorf("invalid TIFF fax block count")
+	}
+	result := &tiffFaxImage{bounds: image.Rect(0, 0, layout.Width, layout.Height), width: int(width), height: int(height), across: int(across)}
+	for i := uint64(0); i < blocks; i++ {
+		if err := ctx.Err(); err != nil {
+			return nil, err
+		}
+		at, err := tiffPlaneValue(data, order, locations, uint32(i))
+		if err != nil {
+			return nil, err
+		}
+		size, err := tiffPlaneValue(data, order, lengths, uint32(i))
+		if err != nil || size == 0 || uint64(at)+uint64(size) > uint64(len(data)) {
+			return nil, fmt.Errorf("truncated TIFF fax block")
+		}
+		encoded := data[uint64(at) : uint64(at)+uint64(size)]
+		if layout.fillOrder == 2 {
+			reversed := make([]byte, len(encoded))
+			for start := 0; start < len(encoded); {
+				if err := ctx.Err(); err != nil {
+					return nil, err
+				}
+				end := start + min(32768, len(encoded)-start)
+				for j := start; j < end; j++ {
+					reversed[j] = bits.Reverse8(encoded[j])
+				}
+				start = end
+			}
+			encoded = reversed
+		}
+		rows := height
+		if !tiled {
+			rows = min(height, uint32(uint64(layout.Height)-i*uint64(height)))
+		}
+		k := pdfgo.Integer(0)
+		if layout.compression == 4 {
+			k = -1
+		} else if layout.compression == 3 && layout.t4&1 != 0 {
+			k = 1
+		}
+		params := pdfgo.Dictionary{
+			"K": k, "Columns": pdfgo.Integer(width), "Rows": pdfgo.Integer(rows),
+			"EndOfBlock": pdfgo.Boolean(false), "EndOfLine": pdfgo.Boolean(layout.compression == 3),
+			"EncodedByteAlign": pdfgo.Boolean(layout.compression == 2), "BlackIs1": pdfgo.Boolean(photo == 1 || photo == 4),
+		}
+		object := &pdfgo.Image{Width: int(width), Height: int(rows), BitsPerComponent: 1, ColorSpace: pdfgo.Name("DeviceGray"), Stream: &pdfgo.Stream{Dictionary: pdfgo.Dictionary{"Filter": pdfgo.Name("CCITTFaxDecode"), "DecodeParms": params}, Data: encoded}}
+		pixels, err := object.DecodeSamplesContext(ctx)
+		if err != nil {
+			return nil, fmt.Errorf("TIFF fax block %d: %w", i, err)
+		}
+		result.blocks = append(result.blocks, pixels)
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	return result, nil
+}
+
+// Bounds 返回主图显示区域，不包含边缘瓦片的填充像素
+// 返回: image.Rectangle 图像区域
+func (s *tiffFaxImage) Bounds() image.Rectangle { return s.bounds }
+
+// ColorModel 返回二值图像使用的灰度颜色模型
+// 返回: color.Model 灰度模型
+func (s *tiffFaxImage) ColorModel() color.Model { return color.GrayModel }
+
+// At 读取所属条带或瓦片中的像素，区域外返回黑色
+// 入参: x 横向像素坐标, y 纵向像素坐标
+// 返回: color.Color 像素颜色
+func (s *tiffFaxImage) At(x, y int) color.Color {
+	if !image.Pt(x, y).In(s.bounds) {
+		return color.Gray{}
+	}
+	block := s.blocks[(y/s.height)*s.across+x/s.width]
+	return block.At(x%s.width, y%s.height)
+}

internal/base/image/tiff_mask.go

@@ -0,0 +1,109 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package image
+
+import (
+	"context"
+	"image"
+	"image/color"
+)
+
+// maskedTIFFImage 将独立透明蒙版叠加到主图，复用两个目录的只读像素
+type maskedTIFFImage struct {
+	source, mask image.Image
+	bounds       image.Rectangle
+}
+
+// DecodeTIFF 解码主图及透明蒙版，保留颜色精度与高分辨率蒙版
+// 入参: ctx 取消上下文，可为nil, data TIFF编码, layout 主图布局
+// 返回: image.Image 图像, error 解码或取消错误
+func DecodeTIFF(ctx context.Context, data []byte, layout TIFFLayout) (image.Image, error) {
+	source, err := decodeTIFFPixels(ctx, data, layout)
+	if err != nil || layout.Transparency == nil {
+		return source, err
+	}
+	mask, err := decodeTIFFPixels(ctx, data, *layout.Transparency)
+	if err != nil {
+		return nil, err
+	}
+	return &maskedTIFFImage{source: source, mask: mask, bounds: image.Rectangle{Max: layout.DisplaySize()}}, nil
+}
+
+// Bounds 返回主图和蒙版共同覆盖的像素区域
+// 返回: image.Rectangle 显示区域
+func (s *maskedTIFFImage) Bounds() image.Rectangle { return s.bounds }
+
+// ColorModel 返回保留原图采样精度的非预乘颜色模型
+// 返回: color.Model 颜色模型
+func (s *maskedTIFFImage) ColorModel() color.Model { return color.NRGBA64Model }
+
+// samplePoint 将显示坐标映射到主图或蒙版的像素中心
+// 入参: bounds 采样图像范围, x 横坐标, y 纵坐标
+// 返回: image.Point 采样坐标
+func (s *maskedTIFFImage) samplePoint(bounds image.Rectangle, x, y int) image.Point {
+	size := s.bounds.Size()
+	x, y = x-s.bounds.Min.X, y-s.bounds.Min.Y
+	if bounds.Size() == size {
+		return bounds.Min.Add(image.Pt(x, y))
+	}
+	return image.Pt(
+		bounds.Min.X+int((uint64(x)*uint64(bounds.Dx())+uint64(bounds.Dx()/2))/uint64(size.X)),
+		bounds.Min.Y+int((uint64(y)*uint64(bounds.Dy())+uint64(bounds.Dy()/2))/uint64(size.Y)),
+	)
+}
+
+// alphaAt 读取蒙版与主图透明度，不解算主图颜色
+// 入参: x 横坐标, y 纵坐标
+// 返回: uint32 十六位透明度
+func (s *maskedTIFFImage) alphaAt(x, y int) uint32 {
+	if !image.Pt(x, y).In(s.bounds) {
+		return 0
+	}
+	mask := s.samplePoint(s.mask.Bounds(), x, y)
+	if NRGBA64At(s.mask, mask.X, mask.Y).R == 0 {
+		return 0
+	}
+	source := s.samplePoint(s.source.Bounds(), x, y)
+	return AlphaAt(s.source, source.X, source.Y)
+}
+
+// NRGBA64At 按像素中心读取主图及蒙版，零位隐藏原图并保留隐藏颜色
+// 入参: x 横坐标, y 纵坐标
+// 返回: color.NRGBA64 非预乘十六位颜色
+func (s *maskedTIFFImage) NRGBA64At(x, y int) color.NRGBA64 {
+	if !image.Pt(x, y).In(s.bounds) {
+		return color.NRGBA64{}
+	}
+	source := s.samplePoint(s.source.Bounds(), x, y)
+	pixel := NRGBA64At(s.source, source.X, source.Y)
+	mask := s.samplePoint(s.mask.Bounds(), x, y)
+	if NRGBA64At(s.mask, mask.X, mask.Y).R == 0 {
+		pixel.A = 0
+	}
+	return pixel
+}
+
+// At 返回非预乘颜色，区域外透明
+// 入参: x 横坐标, y 纵坐标
+// 返回: color.Color 像素颜色
+func (s *maskedTIFFImage) At(x, y int) color.Color { return s.NRGBA64At(x, y) }
+
+// RGBA64At 返回预乘十六位颜色，供采样器直接读取
+// 入参: x 横坐标, y 纵坐标
+// 返回: color.RGBA64 预乘颜色
+func (s *maskedTIFFImage) RGBA64At(x, y int) color.RGBA64 {
+	r, g, b, a := s.NRGBA64At(x, y).RGBA()
+	return color.RGBA64{R: uint16(r), G: uint16(g), B: uint16(b), A: uint16(a)}
+}

internal/base/image/tiff_planar.go

@@ -0,0 +1,807 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package image
+
+import (
+	"bytes"
+	"context"
+	"encoding/binary"
+	"fmt"
+	"image"
+	"image/color"
+	"io"
+	"math"
+
+	"github.com/xiaoqidun/pdfgo"
+)
+
+// tiffPlaneInput 将单分量目录附加到只读视图，像素仍从原始编码读取
+type tiffPlaneInput struct {
+	source, directory []byte
+	position          int64
+	order             binary.ByteOrder
+	ctx               context.Context
+}
+
+// planarTIFFImage 组合颜色与Alpha分量，保留交错步长并按需映射调色板
+type planarTIFFImage struct {
+	planes         []image.Image
+	bounds         image.Rectangle
+	depth          uint32
+	packed         [5]uint32
+	offsets        [5]int
+	alpha          uint32
+	gray           bool
+	cmyk           bool
+	dotRange       [4][2]uint16
+	palette        []color.NRGBA64
+	stride         int
+	invert         bool
+	predictorWidth int
+}
+
+// needsSampleView 判断是否需通过分量视图处理存储布局，供尺寸读取和像素解码共用
+// 返回: bool 是否需要分量视图
+func (layout TIFFLayout) needsSampleView() bool {
+	return layout.mask || layout.auxiliary || layout.photometric == 5 || layout.Planar && layout.Samples > 1 || layout.Samples == 2 || layout.depth < 8 && (layout.Samples > 1 || layout.depth > 1 || layout.predictor == 2)
+}
+
+// DecodedPixelBytes 估算每像素解码缓冲，低位深分量按逐位展开后的字节数计量
+// 返回: uint64 每像素预算字节数
+func (layout TIFFLayout) DecodedPixelBytes() uint64 {
+	samples := uint64(layout.Samples)
+	profile := uint64(0)
+	if layout.profileSize != 0 {
+		profile = 8
+	}
+	if layout.Planar {
+		if layout.photometric == 5 && samples > 4 {
+			return 20 + profile
+		}
+		return 16 + profile
+	}
+	if !layout.needsSampleView() {
+		return 8 + profile
+	}
+	bytes := uint64(1)
+	if layout.depth == 2 || layout.depth == 4 {
+		bytes = uint64(layout.depth)
+	} else if layout.depth > 8 {
+		bytes = 2
+	}
+	return max(uint64(8), samples*bytes) + profile
+}
+
+// decodeTIFFPixels 按存储方式解码指定目录并统一颜色和显示方向
+// 入参: ctx 取消上下文，可为nil, data TIFF编码, layout 目录布局
+// 返回: image.Image 图像, error 解码或取消错误
+func decodeTIFFPixels(ctx context.Context, data []byte, layout TIFFLayout) (image.Image, error) {
+	profile, err := readTIFFColorProfile(ctx, data, layout)
+	if err != nil {
+		return nil, err
+	}
+	var ranges [][2]int64
+	if layout.compression < 2 || layout.compression > 4 {
+		ranges, err = tiffBitOrderRanges(ctx, data, layout)
+		if err != nil {
+			return nil, err
+		}
+	}
+	var pixels image.Image
+	if layout.compression >= 2 && layout.compression <= 4 {
+		pixels, err = decodeTIFFFax(ctx, data, layout)
+		if err != nil {
+			return nil, err
+		}
+	} else if layout.needsSampleView() {
+		result, directories, err := tiffPlaneDirectories(ctx, data, layout)
+		if err != nil {
+			return nil, err
+		}
+		for _, directory := range directories {
+			input := &tiffPlaneInput{source: data, directory: directory, order: binary.LittleEndian, ctx: ctx}
+			if data[0] == 'M' {
+				input.order = binary.BigEndian
+			}
+			plane, err := decodeTIFFBitOrder(input, ranges)
+			if err != nil {
+				return nil, err
+			}
+			if result.predictorWidth != 0 && (result.stride > 1 || result.packed[len(result.planes)] != 0) {
+				if err := restoreTIFFPrediction(ctx, plane, max(result.stride, 1), result.predictorWidth, result.packed[len(result.planes)]); err != nil {
+					return nil, err
+				}
+			}
+			result.planes = append(result.planes, plane)
+		}
+		pixels = result
+	} else {
+		input := newTIFFDirectoryInput(data, layout.Offset)
+		input.ctx = ctx
+		var err error
+		pixels, err = decodeTIFFBitOrder(input, ranges)
+		if err != nil {
+			return nil, err
+		}
+	}
+	if profile != nil {
+		pixels, err = applyTIFFColorProfile(ctx, pixels, profile)
+		if err != nil {
+			return nil, err
+		}
+	}
+	if ctx != nil {
+		if err := ctx.Err(); err != nil {
+			return nil, err
+		}
+	}
+	if layout.Orientation != 1 {
+		pixels = &orientedTIFFImage{source: pixels, TIFFLayout: layout}
+	}
+	return pixels, nil
+}
+
+// tiffPlaneDirectories 为颜色、Alpha或调色板索引构建单通道目录，跳过无显示用途的独立平面
+// 入参: ctx 取消上下文，可为nil, data TIFF编码, layout 已校验的主图布局
+// 返回: *planarTIFFImage 像素布局, [][]byte 各分量目录, error 字段或布局错误
+func tiffPlaneDirectories(ctx context.Context, data []byte, layout TIFFLayout) (*planarTIFFImage, [][]byte, error) {
+	if ctx != nil {
+		if err := ctx.Err(); err != nil {
+			return nil, nil, err
+		}
+	}
+	if uint64(len(data))+65536*12+8 > math.MaxUint32 {
+		return nil, nil, fmt.Errorf("TIFF plane directory offset exceeds format limit")
+	}
+	var order binary.ByteOrder = binary.LittleEndian
+	if data[0] == 'M' {
+		order = binary.BigEndian
+	}
+	offset := int(layout.Offset)
+	count := int(order.Uint16(data[offset:]))
+	entries := make(map[uint16][]byte, count)
+	for i := range count {
+		entry := data[offset+2+i*12 : offset+14+i*12]
+		entries[order.Uint16(entry)] = entry
+	}
+	value := func(tag uint16, fallback uint32) (uint32, error) {
+		entry := entries[tag]
+		if entry == nil {
+			return fallback, nil
+		}
+		if order.Uint32(entry[4:]) != 1 {
+			return 0, fmt.Errorf("invalid TIFF scalar field %d", tag)
+		}
+		return tiffPlaneValue(data, order, entry, 0)
+	}
+	samples, err := value(277, 1)
+	if err != nil || samples < 1 || samples > math.MaxUint16 {
+		return nil, nil, fmt.Errorf("invalid TIFF plane count")
+	}
+	photo, err := value(262, math.MaxUint32)
+	if err != nil || photo > 5 {
+		return nil, nil, fmt.Errorf("unsupported TIFF planar color model")
+	}
+	compression, err := value(259, 1)
+	if err != nil {
+		return nil, nil, err
+	}
+	fill, err := value(266, 1)
+	if err != nil || fill != 1 && (fill != 2 || compression != 1 && (compression < 2 || compression > 4)) {
+		return nil, nil, fmt.Errorf("unsupported TIFF plane fill order")
+	}
+	predictor, err := value(317, 1)
+	if err != nil || predictor != 1 && predictor != 2 {
+		return nil, nil, fmt.Errorf("unsupported TIFF plane predictor")
+	}
+	result := &planarTIFFImage{bounds: image.Rect(0, 0, layout.Width, layout.Height), gray: photo < 2 || photo == 4, invert: photo == 0, cmyk: photo == 5}
+	if result.cmyk {
+		for _, tag := range []uint16{332, 334} {
+			want := uint32(1)
+			if tag == 334 {
+				want = 4
+			}
+			got, err := value(tag, want)
+			if err != nil || got != want || entries[tag] != nil && order.Uint16(entries[tag][2:]) != 3 {
+				return nil, nil, fmt.Errorf("unsupported TIFF ink configuration")
+			}
+		}
+	}
+	planes := samples
+	if !layout.Planar && samples > 1 {
+		result.stride = int(samples)
+		planes = 1
+	}
+	colors := uint32(3)
+	if result.cmyk {
+		colors = 4
+	} else if photo != 2 {
+		colors = 1
+	}
+	if samples != colors {
+		entry := entries[338]
+		if samples < colors || entry == nil || order.Uint16(entry[2:]) != 3 || order.Uint32(entry[4:]) != samples-colors {
+			return nil, nil, fmt.Errorf("invalid TIFF extra samples")
+		}
+		for i := uint32(0); i < samples-colors; i++ {
+			if ctx != nil {
+				if err := ctx.Err(); err != nil {
+					return nil, nil, err
+				}
+			}
+			alpha, err := tiffPlaneValue(data, order, entry, i)
+			if err != nil || alpha > 2 || alpha != 0 && result.alpha != 0 {
+				return nil, nil, fmt.Errorf("unsupported TIFF extra samples")
+			}
+			if alpha != 0 {
+				result.alpha, result.offsets[colors] = alpha, int(i)
+			}
+		}
+	} else if entries[338] != nil {
+		return nil, nil, fmt.Errorf("unexpected TIFF extra samples")
+	}
+	width, err := value(322, 0)
+	if err != nil {
+		return nil, nil, err
+	}
+	blocks := uint64(0)
+	locations, lengths := uint16(273), uint16(279)
+	if width != 0 {
+		height, err := value(323, 0)
+		if err != nil || height == 0 || width%16 != 0 || height%16 != 0 {
+			return nil, nil, fmt.Errorf("invalid TIFF tile dimensions")
+		}
+		blocks = ((uint64(layout.Width)-1)/uint64(width) + 1) * ((uint64(layout.Height)-1)/uint64(height) + 1)
+		locations, lengths = 324, 325
+	} else {
+		rows, err := value(278, math.MaxUint32)
+		if err != nil || rows == 0 {
+			return nil, nil, fmt.Errorf("invalid TIFF rows per strip")
+		}
+		blocks = (uint64(layout.Height)-1)/uint64(rows) + 1
+	}
+	if blocks > math.MaxUint32/uint64(planes) {
+		return nil, nil, fmt.Errorf("too many TIFF plane blocks")
+	}
+	for _, tag := range []uint16{locations, lengths} {
+		entry := entries[tag]
+		if entry == nil || uint64(order.Uint32(entry[4:])) != blocks*uint64(planes) || tag == 324 && order.Uint16(entry[2:]) != 4 {
+			return nil, nil, fmt.Errorf("invalid TIFF plane block count")
+		}
+	}
+	for i := uint32(0); i < uint32(blocks)*planes; i++ {
+		if ctx != nil {
+			if err := ctx.Err(); err != nil {
+				return nil, nil, err
+			}
+		}
+		at, err := tiffPlaneValue(data, order, entries[locations], i)
+		if err != nil {
+			return nil, nil, err
+		}
+		size, err := tiffPlaneValue(data, order, entries[lengths], i)
+		if err != nil || size == 0 || uint64(at)+uint64(size) > uint64(len(data)) {
+			return nil, nil, fmt.Errorf("truncated TIFF plane block")
+		}
+	}
+	for _, tag := range []uint16{258, 339} {
+		if entry := entries[tag]; entry != nil && (order.Uint16(entry[2:]) != 3 || order.Uint32(entry[4:]) != samples) {
+			return nil, nil, fmt.Errorf("invalid TIFF sample array")
+		}
+	}
+	var directories [][]byte
+	var firstDepth uint32
+	for plane := uint32(0); plane < samples; plane++ {
+		if ctx != nil {
+			if err := ctx.Err(); err != nil {
+				return nil, nil, err
+			}
+		}
+		slot := plane
+		visible := plane < colors || result.alpha != 0 && plane == colors+uint32(result.offsets[colors])
+		if !visible && result.stride == 0 {
+			continue
+		}
+		if plane >= colors {
+			slot = colors
+		}
+		depth := uint32(1)
+		if entry := entries[258]; entry != nil {
+			depth, err = tiffPlaneValue(data, order, entry, plane)
+		}
+		if err != nil || depth != 1 && depth != 2 && depth != 4 && depth != 8 && depth != 16 {
+			return nil, nil, fmt.Errorf("unsupported TIFF plane depth")
+		}
+		if plane == 0 {
+			firstDepth = depth
+		} else if result.stride > 1 && depth != firstDepth {
+			return nil, nil, fmt.Errorf("unsupported TIFF mixed interleaved sample depths")
+		}
+		if !visible {
+			continue
+		}
+		result.depth = max(result.depth, depth)
+		if result.cmyk && plane < 4 {
+			low, high := uint32(0), uint32(1<<depth-1)
+			if entry := entries[336]; entry != nil {
+				n := order.Uint32(entry[4:])
+				if kind := order.Uint16(entry[2:]); kind != 1 && kind != 3 || n != 2 && n != 2*samples {
+					return nil, nil, fmt.Errorf("invalid TIFF dot range")
+				}
+				i := plane * 2
+				if n == 2 {
+					i = 0
+				}
+				if order.Uint16(entry[2:]) == 1 {
+					values := entry[8:]
+					if n > 4 {
+						at := uint64(order.Uint32(values))
+						if at+uint64(n) > uint64(len(data)) {
+							return nil, nil, fmt.Errorf("truncated TIFF dot range")
+						}
+						values = data[at : at+uint64(n)]
+					}
+					low, high = uint32(values[i]), uint32(values[i+1])
+				} else {
+					low, err = tiffPlaneValue(data, order, entry, i)
+					if err != nil {
+						return nil, nil, err
+					}
+					high, err = tiffPlaneValue(data, order, entry, i+1)
+				}
+				if err != nil || low == high || low > 1<<depth-1 || high > 1<<depth-1 {
+					return nil, nil, fmt.Errorf("invalid TIFF dot range")
+				}
+			}
+			result.dotRange[plane] = [2]uint16{uint16(low * 65535 / (1<<depth - 1)), uint16(high * 65535 / (1<<depth - 1))}
+		}
+		factor := uint64(max(result.stride, 1))
+		if depth == 1 && predictor == 2 {
+			result.packed[slot] = 1
+		}
+		if depth == 2 || depth == 4 {
+			result.packed[slot] = depth
+			factor *= uint64(depth)
+			if compression == 2 || compression == 3 || compression == 4 {
+				return nil, nil, fmt.Errorf("unsupported TIFF packed plane compression")
+			}
+		}
+		pixelBytes := factor
+		if depth > 8 {
+			pixelBytes *= 2
+		}
+		if uint64(layout.Width)*pixelBytes > uint64(math.MaxInt)/uint64(layout.Height) || uint64(layout.Width)*factor > math.MaxUint32 || uint64(width)*factor > math.MaxUint32 {
+			return nil, nil, fmt.Errorf("TIFF plane dimensions exceed format limit")
+		}
+		if predictor == 2 && (result.stride > 1 || depth < 8) {
+			result.predictorWidth = layout.Width
+			if width != 0 {
+				result.predictorWidth = int(width)
+			}
+		}
+		if entry := entries[339]; entry != nil {
+			format, err := tiffPlaneValue(data, order, entry, plane)
+			if err != nil || format != 1 {
+				return nil, nil, fmt.Errorf("unsupported TIFF sample format")
+			}
+		}
+		if photo == 3 && plane == 0 {
+			entry := entries[320]
+			if depth > 8 || entry == nil || order.Uint16(entry[2:]) != 3 || order.Uint32(entry[4:]) != 3<<depth {
+				return nil, nil, fmt.Errorf("invalid TIFF color map")
+			}
+			n := uint32(1) << depth
+			result.palette = make([]color.NRGBA64, n)
+			for i := range n {
+				var components [3]uint16
+				for c := range components {
+					v, err := tiffPlaneValue(data, order, entry, uint32(c)*n+i)
+					if err != nil {
+						return nil, nil, err
+					}
+					components[c] = uint16(v)
+					if v%257 != 0 {
+						result.depth = 16
+					}
+				}
+				result.palette[i] = color.NRGBA64{R: components[0], G: components[1], B: components[2], A: 65535}
+			}
+		}
+		if result.stride > 1 && plane != 0 {
+			continue
+		}
+		directory := make([]byte, 2, 6+count*12)
+		for i := range count {
+			if ctx != nil {
+				if err := ctx.Err(); err != nil {
+					return nil, nil, err
+				}
+			}
+			entry := bytes.Clone(data[offset+2+i*12 : offset+14+i*12])
+			tag := order.Uint16(entry)
+			if tag == 338 || tag == 320 || tag >= 332 && tag <= 337 || tag == 34675 {
+				continue
+			}
+			scalar := uint32(0)
+			switch tag {
+			case 258:
+				scalar = depth
+				if result.packed[slot] != 0 {
+					scalar = 1
+				}
+			case 256, 322:
+				if factor != 1 {
+					original, err := tiffPlaneValue(data, order, entry, 0)
+					if err != nil {
+						return nil, nil, err
+					}
+					order.PutUint16(entry[2:], 4)
+					order.PutUint32(entry[4:], 1)
+					order.PutUint32(entry[8:], original*uint32(factor))
+				}
+			case 262:
+				scalar = 1
+			case 277, 284, 339:
+				scalar = 1
+			case 317:
+				if predictor == 2 && (result.stride > 1 || depth < 8) {
+					order.PutUint16(entry[8:], 1)
+				}
+			case locations, lengths:
+				entry, err = tiffPlaneArray(data, order, entry, uint32(blocks)*plane, uint32(blocks))
+				if err != nil {
+					return nil, nil, err
+				}
+			}
+			if tag == 258 || tag == 262 || tag == 277 || tag == 284 || tag == 339 {
+				order.PutUint16(entry[2:], 3)
+				order.PutUint32(entry[4:], 1)
+				clear(entry[8:])
+				order.PutUint16(entry[8:], uint16(scalar))
+			}
+			directory = append(directory, entry...)
+		}
+		order.PutUint16(directory, uint16((len(directory)-2)/12))
+		directories = append(directories, append(directory, 0, 0, 0, 0))
+	}
+	return result, directories, nil
+}
+
+// restoreTIFFPrediction 在解码缓冲内恢复水平差分，各行及瓦片独立计算
+// 入参: ctx 取消上下文，可为nil, pixels 单通道解码视图, stride 每像素分量数, width 原始条带或瓦片宽度, packed 展开为一位采样的原位深，零表示未展开
+// 返回: error 图像类型或取消错误
+func restoreTIFFPrediction(ctx context.Context, pixels image.Image, stride, width int, packed uint32) error {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	var data []byte
+	var pitch, step int
+	switch pixels := pixels.(type) {
+	case *image.Gray:
+		data, pitch, step = pixels.Pix, pixels.Stride, max(int(packed), 1)
+	case *image.Gray16:
+		data, pitch, step = pixels.Pix, pixels.Stride, 2
+	default:
+		return fmt.Errorf("unsupported TIFF predictor image")
+	}
+	bounds := pixels.Bounds()
+	columns := bounds.Dx() / max(int(packed), 1)
+	block := width * stride
+	for y := range bounds.Dy() {
+		if err := ctx.Err(); err != nil {
+			return err
+		}
+		row := data[y*pitch : y*pitch+columns*step]
+		for start := 0; start < columns; {
+			end := start + min(block, columns-start)
+			for x := start + stride; x < end; {
+				if err := ctx.Err(); err != nil {
+					return err
+				}
+				limit := x + min(4096, end-x)
+				for ; x < limit; x++ {
+					at, previous := x*step, (x-stride)*step
+					if packed != 0 {
+						var current, prior uint16
+						for bit := range step {
+							current = current<<1 | uint16(row[at+bit]>>7)
+							prior = prior<<1 | uint16(row[previous+bit]>>7)
+						}
+						value := current + prior
+						for bit := range step {
+							row[at+bit] = byte(value>>uint(step-1-bit)&1) * 255
+						}
+					} else if step == 2 {
+						value := binary.BigEndian.Uint16(row[at:]) + binary.BigEndian.Uint16(row[previous:])
+						binary.BigEndian.PutUint16(row[at:], value)
+					} else {
+						row[at] += row[previous]
+					}
+				}
+			}
+			start = end
+		}
+	}
+	return ctx.Err()
+}
+
+// tiffPlaneValue 读取SHORT或LONG数组中的一项，校验完整数组范围
+// 入参: data 原编码, order 字节序, entry 目录项, index 元素序号
+// 返回: uint32 元素值, error 类型或越界错误
+func tiffPlaneValue(data []byte, order binary.ByteOrder, entry []byte, index uint32) (uint32, error) {
+	kind, count := order.Uint16(entry[2:]), order.Uint32(entry[4:])
+	if kind != 3 && kind != 4 || index >= count {
+		return 0, fmt.Errorf("invalid TIFF plane array")
+	}
+	size := uint64(2)
+	if kind == 4 {
+		size = 4
+	}
+	values := entry[8:]
+	if size*uint64(count) > 4 {
+		at := uint64(order.Uint32(values))
+		if at+size*uint64(count) > uint64(len(data)) {
+			return 0, fmt.Errorf("truncated TIFF plane array")
+		}
+		values = data[at:]
+	}
+	if size == 2 {
+		return uint32(order.Uint16(values[uint64(index)*size:])), nil
+	}
+	return order.Uint32(values[uint64(index)*size:]), nil
+}
+
+// tiffPlaneArray 将块索引缩减为指定分量的范围，较长数组继续借用原编码
+// 入参: data 原编码, order 字节序, entry 目录项副本, first 起始序号, count 元素数
+// 返回: []byte 修改后的目录项, error 类型或越界错误
+func tiffPlaneArray(data []byte, order binary.ByteOrder, entry []byte, first, count uint32) ([]byte, error) {
+	if _, err := tiffPlaneValue(data, order, entry, first+count-1); err != nil {
+		return nil, err
+	}
+	size := uint32(2)
+	if order.Uint16(entry[2:]) == 4 {
+		size = 4
+	}
+	if uint64(count)*uint64(size) <= 4 {
+		var values [4]byte
+		for i := uint32(0); i < count; i++ {
+			value, _ := tiffPlaneValue(data, order, entry, first+i)
+			if size == 2 {
+				order.PutUint16(values[i*size:], uint16(value))
+			} else {
+				order.PutUint32(values[i*size:], value)
+			}
+		}
+		copy(entry[8:], values[:])
+	} else {
+		order.PutUint32(entry[8:], order.Uint32(entry[8:])+first*size)
+	}
+	order.PutUint32(entry[4:], count)
+	return entry, nil
+}
+
+// Read 从组合视图顺序读取
+// 入参: data 接收缓冲
+// 返回: int 字节数, error 读取或取消错误
+func (r *tiffPlaneInput) Read(data []byte) (int, error) {
+	n, err := r.ReadAt(data, r.position)
+	r.position += int64(n)
+	return n, err
+}
+
+// ReadAt 从原始编码或附加目录读取并替换首目录指针
+// 入参: data 接收缓冲, offset 文件偏移
+// 返回: int 字节数, error 读取或取消错误
+func (r *tiffPlaneInput) ReadAt(data []byte, offset int64) (int, error) {
+	if r.ctx != nil {
+		if err := r.ctx.Err(); err != nil {
+			return 0, err
+		}
+	}
+	if offset < 0 {
+		return 0, fmt.Errorf("negative TIFF read offset")
+	}
+	start := int64(len(r.source))
+	directory := start + start%2
+	written := 0
+	if offset < start {
+		written = copy(data, r.source[offset:])
+	}
+	if offset+int64(written) == start && start != directory && written < len(data) {
+		data[written] = 0
+		written++
+	}
+	if at := offset + int64(written) - directory; at >= 0 && at < int64(len(r.directory)) {
+		written += copy(data[written:], r.directory[at:])
+	}
+	var pointer [4]byte
+	r.order.PutUint32(pointer[:], uint32(directory))
+	for i, value := range pointer {
+		if at := int64(4+i) - offset; at >= 0 && at < int64(written) {
+			data[at] = value
+		}
+	}
+	if written != len(data) {
+		return written, io.EOF
+	}
+	return written, nil
+}
+
+// Bounds 返回存储坐标范围
+// 返回: image.Rectangle 图像范围
+func (p *planarTIFFImage) Bounds() image.Rectangle { return p.bounds }
+
+// ColorModel 按透明度类型和最高分量精度返回颜色模型
+// 返回: color.Model 颜色模型
+func (p *planarTIFFImage) ColorModel() color.Model {
+	if p.gray && p.alpha == 0 {
+		if p.depth > 8 {
+			return color.Gray16Model
+		}
+		return color.GrayModel
+	}
+	if p.alpha == 1 {
+		if p.depth > 8 || p.cmyk {
+			return color.RGBA64Model
+		}
+		return color.RGBAModel
+	}
+	if p.depth > 8 || p.cmyk {
+		return color.NRGBA64Model
+	}
+	return color.NRGBAModel
+}
+
+// components 直接读取灰度分量，保留原始透明度语义
+// 入参: x 横坐标, y 纵坐标
+// 返回: [4]uint16 红、绿、蓝和透明度分量
+func (p *planarTIFFImage) components(x, y int) [4]uint16 {
+	if !image.Pt(x, y).In(p.bounds) {
+		return [4]uint16{}
+	}
+	if p.cmyk {
+		ink := p.inksAt(x, y)
+		maximum := uint32(65535)
+		if p.alpha == 1 {
+			maximum = uint32(ink[4])
+			if maximum == 0 {
+				return [4]uint16{}
+			}
+		}
+		var components [4]float64
+		for i := range components {
+			components[i] = float64(min(uint32(ink[i]), maximum)) / float64(maximum)
+		}
+		rgb, _ := (&pdfgo.ColorSpace{Model: "DeviceCMYK"}).SRGB(components[:], "")
+		var values [4]uint16
+		for i := range 3 {
+			values[i] = uint16(math.Round(rgb[i] * float64(maximum)))
+		}
+		values[3] = ink[4]
+		return values
+	}
+	values := [4]uint16{0, 0, 0, 65535}
+	count := 3
+	if p.gray || len(p.palette) != 0 {
+		count = 1
+	}
+	if p.alpha != 0 {
+		count++
+	}
+	for i := range count {
+		value := p.sampleAt(i, x, y)
+		if i == 0 && p.invert {
+			value = 65535 - value
+		}
+		if len(p.palette) != 0 && i == 0 {
+			c := p.palette[uint32(value)*uint32(len(p.palette)-1)/65535]
+			values = [4]uint16{c.R, c.G, c.B, c.A}
+		} else if p.gray && i == 0 {
+			values[0], values[1], values[2] = value, value, value
+		} else if p.gray || len(p.palette) != 0 {
+			values[3] = value
+		} else {
+			values[i] = value
+		}
+	}
+	if p.alpha == 1 && values[3] == 0 {
+		return [4]uint16{}
+	}
+	return values
+}
+
+// sampleAt 读取一个分量并扩展为十六位，交错布局复用同一像素缓冲
+// 入参: i 分量序号, x 横坐标, y 纵坐标
+// 返回: uint16 归一化采样值
+func (p *planarTIFFImage) sampleAt(i, x, y int) uint16 {
+	plane, sx := p.planes[0], x
+	if p.stride > 1 {
+		sx = x*p.stride + i + p.offsets[i]
+	} else {
+		plane = p.planes[i]
+	}
+	switch plane := plane.(type) {
+	case *image.Gray:
+		if bits := p.packed[i]; bits != 0 {
+			var value uint16
+			for bit := range int(bits) {
+				value = value<<1 | uint16(plane.GrayAt(sx*int(bits)+bit, y).Y>>7)
+			}
+			return value * (65535 / uint16(1<<bits-1))
+		}
+		return uint16(plane.GrayAt(sx, y).Y) * 257
+	case *image.Gray16:
+		return plane.Gray16At(sx, y).Y
+	default:
+		v, _, _, _ := plane.At(sx, y).RGBA()
+		return uint16(v)
+	}
+}
+
+// inksAt 按网点范围读取CMYK覆盖量，范围外采样按端点截断，透明度独立归一化
+// 入参: x 横坐标, y 纵坐标
+// 返回: [5]uint16 青、品红、黄、黑及透明度
+func (p *planarTIFFImage) inksAt(x, y int) [5]uint16 {
+	values := [5]uint16{0, 0, 0, 0, 65535}
+	for i := range 4 {
+		value := int64(p.sampleAt(i, x, y))
+		low, high := int64(p.dotRange[i][0]), int64(p.dotRange[i][1])
+		values[i] = uint16(max(0, min(65535, (value-low)*65535/(high-low))))
+	}
+	if p.alpha != 0 {
+		values[4] = p.sampleAt(4, x, y)
+	}
+	return values
+}
+
+// At 返回组合后的颜色，关联透明度保留预乘语义
+// 入参: x 横坐标, y 纵坐标
+// 返回: color.Color 像素颜色
+func (p *planarTIFFImage) At(x, y int) color.Color {
+	values := p.components(x, y)
+	if p.alpha == 1 {
+		return color.RGBA64{R: values[0], G: values[1], B: values[2], A: values[3]}
+	}
+	return color.NRGBA64{R: values[0], G: values[1], B: values[2], A: values[3]}
+}
+
+// NRGBA64At 读取独立透明度颜色，保留非预乘分量中的隐藏颜色
+// 入参: x 横坐标, y 纵坐标
+// 返回: color.NRGBA64 像素颜色
+func (p *planarTIFFImage) NRGBA64At(x, y int) color.NRGBA64 {
+	values := p.components(x, y)
+	if p.alpha == 1 && values[3] != 65535 {
+		if values[3] == 0 {
+			return color.NRGBA64{}
+		}
+		for i := range 3 {
+			values[i] = uint16(uint32(values[i]) * 65535 / uint32(values[3]))
+		}
+	}
+	return color.NRGBA64{R: values[0], G: values[1], B: values[2], A: values[3]}
+}
+
+// RGBA64At 返回预乘十六位颜色，不分配临时颜色对象
+// 入参: x 横坐标, y 纵坐标
+// 返回: color.RGBA64 像素颜色
+func (p *planarTIFFImage) RGBA64At(x, y int) color.RGBA64 {
+	values := p.components(x, y)
+	if p.alpha != 1 && values[3] != 65535 {
+		for i := range 3 {
+			values[i] = uint16(uint32(values[i]) * uint32(values[3]) / 65535)
+		}
+	}
+	return color.RGBA64{R: values[0], G: values[1], B: values[2], A: values[3]}
+}

internal/base/image/tiff_profile.go

@@ -0,0 +1,248 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package image
+
+import (
+	"context"
+	"fmt"
+	"image"
+	"image/color"
+	"math"
+	"strings"
+
+	"github.com/xiaoqidun/pdfgo"
+)
+
+// parseTIFFColorProfile 校验ICC源模型，保留原有模型错误并复用浮点颜色变换
+// 入参: kind 源颜色模型, data ICC编码
+// 返回: *pdfgo.ColorSpace 颜色变换, error 模型或配置错误
+func parseTIFFColorProfile(kind string, data []byte) (*pdfgo.ColorSpace, error) {
+	model := map[string]string{"GRAY": "GRAY", "RGB": "RGB ", "CMYK": "CMYK"}[strings.ToUpper(kind)]
+	if len(data) < 132 || model == "" || string(data[16:20]) != model {
+		return nil, fmt.Errorf("ICC source model does not match image color space %q", kind)
+	}
+	return pdfgo.NewICCColorSpace(data)
+}
+
+// readTIFFColorProfile 读取主图的ICC配置，校验颜色模型和数据范围
+// 入参: ctx 取消上下文，可为nil, data TIFF编码, layout 主图布局
+// 返回: *pdfgo.ColorSpace 颜色配置，未声明时为nil, error 配置或取消错误
+func readTIFFColorProfile(ctx context.Context, data []byte, layout TIFFLayout) (*pdfgo.ColorSpace, error) {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	if layout.profileSize == 0 {
+		return nil, nil
+	}
+	at, size := uint64(layout.profileOffset), uint64(layout.profileSize)
+	if at+size > uint64(len(data)) {
+		return nil, fmt.Errorf("truncated TIFF color profile")
+	}
+	kind := ""
+	switch layout.photometric {
+	case 0, 1:
+		kind = "GRAY"
+	case 2, 3:
+		kind = "RGB"
+	case 5:
+		kind = "CMYK"
+	default:
+		return nil, fmt.Errorf("unsupported TIFF profile color model")
+	}
+	profile, err := parseTIFFColorProfile(kind, data[at:at+size])
+	if cancelErr := ctx.Err(); cancelErr != nil {
+		return nil, cancelErr
+	}
+	return profile, err
+}
+
+// applyTIFFColorProfile 将源颜色转换为十六位sRGB，保留独立透明度和隐藏颜色
+// 入参: ctx 取消上下文，可为nil, source 解码图像, profile 已校验的颜色配置
+// 返回: image.Image 独立透明度图像, error 颜色变换或取消错误
+func applyTIFFColorProfile(ctx context.Context, source image.Image, profile *pdfgo.ColorSpace) (image.Image, error) {
+	return applyImageColorProfile(ctx, source, profile, false)
+}
+
+// applyImageColorProfile 按源配置转换显示像素，精确复用连续同色结果
+// 入参: ctx 取消上下文, source 源像素, profile 颜色空间, linearSRGB 是否先解码sRGB传递函数
+// 返回: image.Image 十六位显示图像, error 变换或取消错误
+func applyImageColorProfile(ctx context.Context, source image.Image, profile *pdfgo.ColorSpace, linearSRGB bool) (image.Image, error) {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	bounds := source.Bounds()
+	if bounds.Dx() <= 0 || bounds.Dy() <= 0 || bounds.Dx() > math.MaxInt/8/bounds.Dy() {
+		return nil, fmt.Errorf("TIFF profile image dimensions exceed capacity")
+	}
+	cmyk, _ := source.(*planarTIFFImage)
+	if cmyk != nil && !cmyk.cmyk {
+		cmyk = nil
+	}
+	model := source.ColorModel()
+	premultiplied := model == color.RGBAModel || model == color.RGBA64Model
+	table := newTIFFProfileTable(source)
+	components, intent := profile.Components(), profile.DefaultIntent()
+	result := image.NewNRGBA64(bounds)
+	var previous [4]float64
+	var previousPixel color.NRGBA64
+	for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
+		for x := bounds.Min.X; x < bounds.Max.X; x++ {
+			if (x-bounds.Min.X)&255 == 0 {
+				if err := ctx.Err(); err != nil {
+					return nil, err
+				}
+			}
+			slot := -1
+			if len(table) != 0 {
+				index, alpha := tiffProfileSample(source, x, y, len(table))
+				slot = index
+				if pixel := table[index]; pixel.A != 0 {
+					pixel.A = alpha
+					result.SetNRGBA64(x, y, pixel)
+					continue
+				}
+			}
+			var values [4]float64
+			var alpha uint16
+			if cmyk != nil {
+				ink := cmyk.inksAt(x, y)
+				alpha = ink[4]
+				if cmyk.alpha == 1 && alpha == 0 {
+					continue
+				}
+				maximum := float64(65535)
+				if cmyk.alpha == 1 {
+					maximum = float64(alpha)
+				}
+				for i := range values {
+					values[i] = min(1, float64(ink[i])/maximum)
+				}
+			} else if premultiplied {
+				var pixel color.RGBA64
+				if native, ok := source.(image.RGBA64Image); ok {
+					pixel = native.RGBA64At(x, y)
+				} else {
+					pixel = color.RGBA64Model.Convert(source.At(x, y)).(color.RGBA64)
+				}
+				alpha = pixel.A
+				if alpha == 0 {
+					continue
+				}
+				for i, value := range [3]uint16{pixel.R, pixel.G, pixel.B} {
+					values[i] = min(1, float64(value)/float64(alpha))
+				}
+			} else {
+				pixel := NRGBA64At(source, x, y)
+				alpha = pixel.A
+				values = [4]float64{float64(pixel.R) / 65535, float64(pixel.G) / 65535, float64(pixel.B) / 65535}
+			}
+			if previousPixel.A != 0 && values == previous {
+				pixel := previousPixel
+				pixel.A = alpha
+				result.SetNRGBA64(x, y, pixel)
+				continue
+			}
+			previous = values
+			if linearSRGB {
+				for i := range 3 {
+					if values[i] <= 0.04045 {
+						values[i] /= 12.92
+					} else {
+						values[i] = math.Pow((values[i]+0.055)/1.055, 2.4)
+					}
+				}
+			}
+			rgb, err := profile.SRGB(values[:components], intent)
+			if err != nil {
+				return nil, err
+			}
+			var channels [3]uint16
+			for i, value := range rgb {
+				channels[i] = uint16(math.Round(max(0, min(1, value)) * 65535))
+			}
+			previousPixel = color.NRGBA64{R: channels[0], G: channels[1], B: channels[2], A: 65535}
+			if slot >= 0 {
+				table[slot] = color.NRGBA64{R: channels[0], G: channels[1], B: channels[2], A: 65535}
+			}
+			result.SetNRGBA64(x, y, color.NRGBA64{R: channels[0], G: channels[1], B: channels[2], A: alpha})
+		}
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	return &colorImage{NRGBA64: result, source: source}, nil
+}
+
+// newTIFFProfileTable 为离散颜色分配查找表，预乘颜色及小图保持逐像素变换
+// 入参: source 已解码且尺寸有效的图像
+// 返回: []color.NRGBA64 颜色表，Alpha非零表示已有结果，不适用时为nil
+func newTIFFProfileTable(source image.Image) []color.NRGBA64 {
+	count := 0
+	switch source := source.(type) {
+	case *image.Gray:
+		count = 256
+	case *image.Gray16:
+		count = 65536
+	case *image.Paletted:
+		count = len(source.Palette)
+	case *planarTIFFImage:
+		if source.alpha != 1 {
+			if len(source.palette) != 0 {
+				count = len(source.palette)
+			} else if source.gray {
+				count = 256
+				if source.packed[0] != 0 {
+					count = 1 << source.packed[0]
+				} else if _, ok := source.planes[0].(*image.Gray16); ok {
+					count = 65536
+				}
+			}
+		}
+	}
+	if count == 0 || count >= source.Bounds().Dx()*source.Bounds().Dy() {
+		return nil
+	}
+	return make([]color.NRGBA64, count)
+}
+
+// tiffProfileSample 读取查找表索引与独立透明度，颜色键不包含透明度
+// 入参: source 适用查找表的图像, x 横坐标, y 纵坐标, count 颜色表长度
+// 返回: int 颜色索引, uint16 透明度
+func tiffProfileSample(source image.Image, x, y, count int) (int, uint16) {
+	switch source := source.(type) {
+	case *image.Gray:
+		return int(source.GrayAt(x, y).Y), 65535
+	case *image.Gray16:
+		return int(source.Gray16At(x, y).Y), 65535
+	case *image.Paletted:
+		index := source.ColorIndexAt(x, y)
+		_, _, _, alpha := source.Palette[index].RGBA()
+		return int(index), uint16(alpha)
+	case *planarTIFFImage:
+		index := int(uint32(source.sampleAt(0, x, y)) * uint32(count-1) / 65535)
+		alpha := uint16(65535)
+		if source.alpha != 0 {
+			alpha = source.sampleAt(1, x, y)
+		}
+		return index, alpha
+	}
+	return 0, 0
+}

internal/base/threed/u3d.go

@@ -0,0 +1,680 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package threed
+
+import (
+	"bytes"
+	"context"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"math"
+)
+
+// DefaultBytes 限制默认解码数据规模，不包括调用方已有输入及运行时开销
+const DefaultBytes = 256 << 20
+
+// U3DOptions 控制U3D解码规模，MaxDecodedBytes为0时采用256MiB上限
+type U3DOptions struct {
+	MaxDecodedBytes int64
+}
+
+// U3DModel 保存独立于PDF的U3D场景及动作数据，不执行动作或读取外部文件
+type U3DModel struct {
+	Major, Minor int16
+	DefinedUnits bool
+	Units        float64
+	Meshes       []U3DMesh
+	Nodes        []U3DNode
+	Materials    []U3DMaterial
+	Shaders      []U3DShader
+	Lights       []U3DLight
+	Views        []U3DViewResource
+	Textures     []U3DTexture
+	Motions      []U3DMotion
+	Metadata     []U3DMetadata
+}
+
+// U3DMetadata 保留块所属名称与原始元数据，数据不与输入共享存储
+type U3DMetadata struct {
+	Block uint32
+	Name  string
+	Data  []byte
+}
+
+// U3DNode 保存组、模型、光源或视图节点，父节点矩阵按列存储
+type U3DNode struct {
+	Name, Kind, Resource string
+	Parents              []U3DParent
+	Visibility           uint32
+	Shaders              [][]string
+	LineShaders          [][]string
+	PointShaders         [][]string
+	View                 *U3DView
+	BoneWeights          []U3DBoneWeights
+	Animations           []U3DAnimation
+}
+
+// U3DParent 保存父节点名称及局部到父节点的变换，空名称引用默认节点
+type U3DParent struct {
+	Name      string
+	Transform [16]float32
+}
+
+// U3DMaterial 保存材质参数，Attributes各位决定相应参数是否生效
+type U3DMaterial struct {
+	Name                                 string
+	Attributes                           uint32
+	Ambient, Diffuse, Specular, Emissive [3]float32
+	Reflectivity, Opacity                float32
+}
+
+// U3DShader 保存材质与八个纹理通道，Textures中的空项表示未启用
+type U3DShader struct {
+	Name, Material                   string
+	Attributes, AlphaFunction, Blend uint32
+	RenderPass                       uint32
+	AlphaReference                   float32
+	Textures                         [8]*U3DTextureLayer
+}
+
+// U3DLight 保存环境、方向、点或聚光资源，Kind依次为0至3
+type U3DLight struct {
+	Name                 string
+	Attributes           uint32
+	Kind                 byte
+	Color, Attenuation   [3]float32
+	SpotAngle, Intensity float32
+}
+
+// u3dBlock 保存校验后的块边界，数据切片仅在解码期间引用输入
+type u3dBlock struct {
+	kind       uint32
+	data, meta []byte
+}
+
+// u3dDecoder 保存单次解码预算及场景索引，不跨调用缓存输入
+type u3dDecoder struct {
+	ctx       context.Context
+	model     U3DModel
+	remaining uint64
+	plain     bool
+	meshes    map[string]*u3dMeshDeclaration
+	meshOrder []string
+	nodes     map[string]int
+	palettes  map[uint32]map[string]bool
+	textures  map[string]int
+}
+
+// DecodeU3D 按ECMA-363解码静态几何、骨架、场景节点及材质、纹理图像等资源
+// 保留动作轨道和动画修饰器，不在解码时求值；绘制能力由RenderU3D另行校验
+// 渐进网格尚未支持
+// 点集球面预测暂限不超过两个非对跖方向，不推测多方向合并次序
+// 入参: ctx 取消上下文, data U3D数据, options 解码限制
+// 返回: *U3DModel 独立场景数据, error 格式、能力、预算或取消错误
+func DecodeU3D(ctx context.Context, data []byte, options U3DOptions) (*U3DModel, error) {
+	if ctx == nil || options.MaxDecodedBytes < 0 {
+		return nil, fmt.Errorf("invalid U3D decode options")
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	limit := options.MaxDecodedBytes
+	if limit == 0 {
+		limit = DefaultBytes
+	}
+	d := u3dDecoder{ctx: ctx, remaining: uint64(limit), meshes: make(map[string]*u3dMeshDeclaration), nodes: make(map[string]int), palettes: make(map[uint32]map[string]bool)}
+	header, next, err := u3dReadBlock(data, 0)
+	if err != nil {
+		return nil, err
+	}
+	if header.kind != 0x00443355 {
+		return nil, fmt.Errorf("invalid U3D file header")
+	}
+	r := u3dValues{data: header.data}
+	version, profile := r.u32(), r.u32()
+	d.model.Major, d.model.Minor = int16(version), int16(version>>16)
+	if d.model.Major > 0 || profile & ^uint32(14) != 0 {
+		return nil, fmt.Errorf("unsupported U3D version or profile")
+	}
+	declarationEnd := uint64(r.u32())
+	fileSize := uint64(r.u32())
+	fileSize |= uint64(r.u32()) << 32
+	if r.u32() != 106 {
+		return nil, fmt.Errorf("unsupported U3D character encoding")
+	}
+	d.plain = profile&4 != 0
+	d.model.DefinedUnits, d.model.Units = profile&8 != 0, 1
+	if d.model.DefinedUnits {
+		unitBytes := r.take(8)
+		if r.err == nil {
+			d.model.Units = math.Float64frombits(binary.LittleEndian.Uint64(unitBytes))
+			if !finite(d.model.Units) || d.model.Units <= 0 {
+				return nil, fmt.Errorf("invalid U3D units")
+			}
+		}
+	}
+	if err := r.done(); err != nil {
+		return nil, err
+	}
+	if fileSize != uint64(len(data)) || declarationEnd < uint64(next) || declarationEnd > fileSize || declarationEnd%4 != 0 {
+		return nil, fmt.Errorf("invalid U3D file size")
+	}
+	if err := d.metadata(header, ""); err != nil {
+		return nil, err
+	}
+	priority := uint32(0)
+	for offset := next; offset < len(data); {
+		if err := ctx.Err(); err != nil {
+			return nil, err
+		}
+		block, end, err := u3dReadBlock(data, offset)
+		if err != nil {
+			return nil, fmt.Errorf("U3D block at %d: %w", offset, err)
+		}
+		continuation := block.kind == 0xffffff15 || block.kind == 0xffffff3b || block.kind == 0xffffff3c || block.kind == 0xffffff3e || block.kind == 0xffffff3f || block.kind == 0xffffff5c
+		if uint64(offset) < declarationEnd && (uint64(end) > declarationEnd || continuation) || uint64(offset) >= declarationEnd && !continuation {
+			return nil, fmt.Errorf("invalid U3D declaration boundary at %d", offset)
+		}
+		if block.kind == 0xffffff15 {
+			r := u3dValues{data: block.data}
+			value := r.u32()
+			if err := r.done(); err != nil {
+				return nil, err
+			}
+			if value == 0 || value < priority || value > 0x7fffffff {
+				return nil, fmt.Errorf("invalid U3D block priority")
+			}
+			priority = value
+			err = d.metadata(block, "")
+		} else if block.kind == 0xffffff14 {
+			err = d.chain(block)
+		} else {
+			_, err = d.block(block, "", -1, 0)
+		}
+		if err != nil {
+			return nil, fmt.Errorf("U3D block %#x at %d: %w", block.kind, offset, err)
+		}
+		offset = end
+	}
+	for _, name := range d.meshOrder {
+		mesh := d.meshes[name]
+		if !mesh.decoded && mesh.counts[1] != 0 {
+			return nil, fmt.Errorf("missing U3D base mesh %q", name)
+		}
+		d.model.Meshes = append(d.model.Meshes, mesh.mesh)
+	}
+	if err := d.checkTextures(); err != nil {
+		return nil, err
+	}
+	if err := d.checkParents(); err != nil {
+		return nil, err
+	}
+	if err := d.checkBoneWeights(); err != nil {
+		return nil, err
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	return &d.model, nil
+}
+
+// u3dReadBlock 按64位长度计算校验块数据与零填充，避免长度溢出
+// 入参: data 块序列, offset 块起点
+// 返回: u3dBlock 块, int 下一块起点, error 边界或填充错误
+func u3dReadBlock(data []byte, offset int) (u3dBlock, int, error) {
+	if offset < 0 || offset > len(data) || len(data)-offset < 12 {
+		return u3dBlock{}, 0, io.ErrUnexpectedEOF
+	}
+	header := data[offset : offset+12]
+	size, meta := uint64(binary.LittleEndian.Uint32(header[4:])), uint64(binary.LittleEndian.Uint32(header[8:]))
+	start := uint64(offset) + 12
+	metaStart := start + ((size + 3) &^ 3)
+	end := metaStart + ((meta + 3) &^ 3)
+	if end > uint64(len(data)) {
+		return u3dBlock{}, 0, io.ErrUnexpectedEOF
+	}
+	for _, padding := range [][]byte{data[start+size : metaStart], data[metaStart+meta : end]} {
+		for _, value := range padding {
+			if value != 0 {
+				return u3dBlock{}, 0, fmt.Errorf("invalid U3D padding")
+			}
+		}
+	}
+	return u3dBlock{binary.LittleEndian.Uint32(header), data[start : start+size], data[metaStart : metaStart+meta]}, int(end), nil
+}
+
+// reserve 在分配解码数组前检查总预算及取消状态
+// 入参: count 元素数量, size 元素规模上界
+// 返回: error 预算或取消错误
+func (d *u3dDecoder) reserve(count, size uint64) error {
+	if err := d.ctx.Err(); err != nil {
+		return err
+	}
+	if size == 0 || count > d.remaining/size || count > uint64(^uint(0)>>1)/size {
+		return fmt.Errorf("U3D decoded data exceeds limit")
+	}
+	d.remaining -= count * size
+	return nil
+}
+
+// metadata 校验元数据结构并保留原始数据，不解释或执行其中的动作
+// 入参: block 数据块, name 所属资源名
+// 返回: error 结构、预算或取消错误
+func (d *u3dDecoder) metadata(block u3dBlock, name string) error {
+	if len(block.meta) == 0 {
+		return nil
+	}
+	if err := d.reserve(uint64(len(block.meta))+128, 1); err != nil {
+		return err
+	}
+	r := u3dValues{data: block.meta}
+	count := r.u32()
+	if uint64(count) > uint64(len(block.meta))/8 {
+		return fmt.Errorf("invalid U3D metadata count")
+	}
+	for range count {
+		if err := d.ctx.Err(); err != nil {
+			return err
+		}
+		flags := r.u32()
+		r.text()
+		if flags&1 != 0 {
+			size := r.u32()
+			if uint64(size) > uint64(len(r.data)-r.pos) {
+				return io.ErrUnexpectedEOF
+			}
+			r.take(int(size))
+		} else {
+			r.text()
+		}
+		if r.err != nil {
+			return r.err
+		}
+	}
+	if err := r.done(); err != nil {
+		return err
+	}
+	d.model.Metadata = append(d.model.Metadata, U3DMetadata{block.kind, name, bytes.Clone(block.meta)})
+	return nil
+}
+
+// chain 解析单层修饰链并校验名称、链类型与修饰顺序
+// 入参: block 修饰链块
+// 返回: error 结构、能力或资源错误
+func (d *u3dDecoder) chain(block u3dBlock) error {
+	if err := d.reserve(256, 1); err != nil {
+		return err
+	}
+	r := u3dValues{data: block.data}
+	name, kind, flags := r.text(), r.u32(), r.u32()
+	if r.err != nil {
+		return r.err
+	}
+	if name == "" {
+		return fmt.Errorf("cannot redefine U3D default resource")
+	}
+	if kind > 2 || flags & ^uint32(3) != 0 {
+		return fmt.Errorf("invalid U3D modifier chain")
+	}
+	if flags&1 != 0 {
+		for range 4 {
+			r.f32()
+		}
+	}
+	if flags&2 != 0 {
+		for range 6 {
+			r.f32()
+		}
+	}
+	for r.pos%4 != 0 && r.err == nil {
+		if r.u8() != 0 {
+			return fmt.Errorf("invalid U3D chain padding")
+		}
+	}
+	count := r.u32()
+	if r.err != nil {
+		return r.err
+	}
+	if uint64(count) > uint64(len(r.data)-r.pos)/12 {
+		return fmt.Errorf("invalid U3D modifier count")
+	}
+	for index := uint32(0); index < count; index++ {
+		if err := d.ctx.Err(); err != nil {
+			return err
+		}
+		nested, next, err := u3dReadBlock(r.data, r.pos)
+		if err != nil {
+			return err
+		}
+		actual, err := d.block(nested, name, int(kind), index)
+		if err != nil {
+			return err
+		}
+		if actual != name {
+			return fmt.Errorf("U3D modifier name mismatch")
+		}
+		r.pos = next
+	}
+	if err := r.done(); err != nil {
+		return err
+	}
+	return d.metadata(block, name)
+}
+
+// block 解析支持的静态场景块，不丢弃未实现的修饰器或几何
+// 入参: block 数据块, owner 所属链名, chain 链类别，负值表示独立块, index 修饰位置
+// 返回: string 资源名, error 格式、能力或资源错误
+func (d *u3dDecoder) block(block u3dBlock, owner string, chain int, index uint32) (string, error) {
+	if err := d.ctx.Err(); err != nil {
+		return "", err
+	}
+	if err := d.reserve(uint64(len(block.data))+256, 1); err != nil {
+		return "", err
+	}
+	r := u3dValues{data: block.data}
+	name := r.text()
+	if r.err != nil {
+		return "", r.err
+	}
+	if name == "" {
+		return "", fmt.Errorf("cannot redefine U3D default resource")
+	}
+	var err error
+	switch block.kind {
+	case 0xffffff21, 0xffffff22, 0xffffff23, 0xffffff24:
+		if chain >= 0 && (chain != 0 || index != 0) {
+			return name, fmt.Errorf("invalid U3D node chain")
+		}
+		err = d.node(&r, block.kind, name)
+	case 0xffffff31:
+		if chain >= 0 && (chain != 1 || index != 0) {
+			return name, fmt.Errorf("invalid U3D mesh chain")
+		}
+		err = d.meshDeclaration(&r, name)
+	case 0xffffff3b:
+		if chain >= 0 {
+			return name, fmt.Errorf("invalid U3D mesh continuation location")
+		}
+		err = d.baseMesh(&r, name)
+	case 0xffffff36, 0xffffff37:
+		if chain >= 0 && (chain != 1 || index != 0) {
+			return name, fmt.Errorf("invalid U3D primitive chain")
+		}
+		err = d.primitiveDeclaration(&r, name, block.kind == 0xffffff36)
+	case 0xffffff3e, 0xffffff3f:
+		if chain >= 0 {
+			return name, fmt.Errorf("invalid U3D primitive continuation location")
+		}
+		err = d.primitiveContinuation(&r, name, block.kind == 0xffffff3e)
+	case 0xffffff43, 0xffffff44:
+		if (chain != 0 && chain != 1) || index == 0 || owner != name || r.u32() != index {
+			return name, fmt.Errorf("invalid U3D animation or bone weight modifier chain")
+		}
+		if _, exists := d.nodes[name]; chain == 0 && !exists || chain == 1 && d.meshes[name] == nil {
+			return name, fmt.Errorf("missing U3D animation or bone weight modifier target")
+		}
+		if block.kind == 0xffffff43 {
+			err = d.animation(&r, name, chain, index)
+		} else {
+			err = d.boneWeights(&r, name, chain, index)
+		}
+	case 0xffffff45:
+		if chain != 0 || index == 0 || owner != name || r.u32() != index {
+			return name, fmt.Errorf("invalid U3D shading modifier chain")
+		}
+		err = d.shading(&r, name)
+	case 0xffffff51, 0xffffff52, 0xffffff53, 0xffffff54, 0xffffff56:
+		if chain >= 0 {
+			return name, fmt.Errorf("invalid U3D palette resource location")
+		}
+		err = d.resource(&r, block.kind, name)
+	case 0xffffff55:
+		if chain >= 0 && (chain != 2 || index != 0) {
+			return name, fmt.Errorf("invalid U3D texture chain")
+		}
+		err = d.textureDeclaration(&r, name)
+	case 0xffffff5c:
+		if chain >= 0 {
+			return name, fmt.Errorf("invalid U3D texture continuation location")
+		}
+		err = d.textureContinuation(&r, name)
+	default:
+		return name, fmt.Errorf("unsupported U3D block %#x", block.kind)
+	}
+	if err != nil {
+		return name, err
+	}
+	if err := r.done(); err != nil {
+		return name, err
+	}
+	return name, d.metadata(block, name)
+}
+
+// node 读取节点与父变换，允许引用后续声明的父节点
+// 入参: r 字段读取器, kind 节点类型, name 节点名
+// 返回: error 结构或预算错误
+func (d *u3dDecoder) node(r *u3dValues, kind uint32, name string) error {
+	if _, exists := d.nodes[name]; exists {
+		return fmt.Errorf("duplicate U3D node %q", name)
+	}
+	node := U3DNode{Name: name, Kind: "Group"}
+	count := r.u32()
+	if uint64(count) > uint64(len(r.data)-r.pos)/66 {
+		return io.ErrUnexpectedEOF
+	}
+	if err := d.reserve(uint64(count), 96); err != nil {
+		return err
+	}
+	node.Parents = make([]U3DParent, int(count))
+	for index := range node.Parents {
+		if index%256 == 0 {
+			if err := d.ctx.Err(); err != nil {
+				return err
+			}
+		}
+		node.Parents[index].Name = r.text()
+		for element := range node.Parents[index].Transform {
+			node.Parents[index].Transform[element] = r.f32()
+		}
+	}
+	if kind == 0xffffff22 {
+		node.Kind, node.Resource, node.Visibility = "Model", r.text(), r.u32()
+		if node.Visibility > 3 {
+			return fmt.Errorf("invalid U3D model visibility")
+		}
+	} else if kind == 0xffffff23 {
+		node.Kind, node.Resource = "Light", r.text()
+	} else if kind == 0xffffff24 {
+		node.Kind, node.Resource = "View", r.text()
+		var err error
+		node.View, err = d.view(r)
+		if err != nil {
+			return err
+		}
+	}
+	d.nodes[name] = len(d.model.Nodes)
+	d.model.Nodes = append(d.model.Nodes, node)
+	return r.err
+}
+
+// shading 分别读取网格、线集和点集着色列表，保留列表内各着色器的先后次序
+// 入参: r 字段读取器, name 目标节点名
+// 返回: error 结构、能力或预算错误
+func (d *u3dDecoder) shading(r *u3dValues, name string) error {
+	index, exists := d.nodes[name]
+	if !exists || d.model.Nodes[index].Kind != "Model" {
+		return fmt.Errorf("missing U3D shading target")
+	}
+	flags := r.u32()
+	if flags & ^uint32(7) != 0 {
+		return fmt.Errorf("unsupported U3D shading modifier target")
+	}
+	count := r.u32()
+	if uint64(count) > uint64(len(r.data)-r.pos)/4 {
+		return io.ErrUnexpectedEOF
+	}
+	if err := d.reserve(uint64(count), 24); err != nil {
+		return err
+	}
+	lists := make([][]string, int(count))
+	for index := range lists {
+		n := r.u32()
+		if uint64(n) > uint64(len(r.data)-r.pos)/2 {
+			return io.ErrUnexpectedEOF
+		}
+		if err := d.reserve(uint64(n), 16); err != nil {
+			return err
+		}
+		lists[index] = make([]string, int(n))
+		for j := range lists[index] {
+			if j%256 == 0 {
+				if err := d.ctx.Err(); err != nil {
+					return err
+				}
+			}
+			lists[index][j] = r.text()
+		}
+	}
+	if flags&1 != 0 {
+		d.model.Nodes[index].Shaders = lists
+	}
+	if flags&2 != 0 {
+		d.model.Nodes[index].LineShaders = lists
+	}
+	if flags&4 != 0 {
+		d.model.Nodes[index].PointShaders = lists
+	}
+	return r.err
+}
+
+// resource 读取独立材质、着色器、光源、视图和动作资源
+// 入参: r 字段读取器, kind 资源类型, name 资源名
+// 返回: error 结构或能力错误
+func (d *u3dDecoder) resource(r *u3dValues, kind uint32, name string) error {
+	palette := d.palettes[kind]
+	if palette == nil {
+		palette = make(map[string]bool)
+		d.palettes[kind] = palette
+	}
+	if palette[name] {
+		return fmt.Errorf("duplicate U3D resource %q", name)
+	}
+	palette[name] = true
+	switch kind {
+	case 0xffffff56:
+		return d.motion(r, name)
+	case 0xffffff52:
+		return d.viewResource(r, name)
+	case 0xffffff54:
+		material := U3DMaterial{Name: name, Attributes: r.u32()}
+		if material.Attributes & ^uint32(63) != 0 {
+			return fmt.Errorf("invalid U3D material attributes")
+		}
+		for _, color := range []*[3]float32{&material.Ambient, &material.Diffuse, &material.Specular, &material.Emissive} {
+			for index := range color {
+				color[index] = r.f32()
+			}
+		}
+		material.Reflectivity, material.Opacity = r.f32(), r.f32()
+		d.model.Materials = append(d.model.Materials, material)
+	case 0xffffff53:
+		shader := U3DShader{Name: name, Attributes: r.u32(), AlphaReference: r.f32(), AlphaFunction: r.u32(), Blend: r.u32(), RenderPass: r.u32()}
+		channels, alpha := r.u32(), r.u32()
+		shader.Material = r.text()
+		if shader.Attributes & ^uint32(7) != 0 || shader.AlphaFunction < 0x610 || shader.AlphaFunction > 0x617 || shader.Blend < 0x604 || shader.Blend > 0x607 || channels & ^uint32(255) != 0 || alpha & ^channels != 0 {
+			return fmt.Errorf("invalid U3D shader parameters")
+		}
+		for channel := range shader.Textures {
+			if channels&(1<<channel) == 0 {
+				continue
+			}
+			if err := d.reserve(1, 192); err != nil {
+				return err
+			}
+			layer := &U3DTextureLayer{Texture: r.text(), Intensity: r.f32(), Blend: r.u8(), BlendSource: r.u8(), BlendConstant: r.f32(), Mode: r.u8(), Alpha: alpha&(1<<channel) != 0}
+			for i := range layer.Transform {
+				layer.Transform[i] = r.f32()
+			}
+			for i := range layer.WrapTransform {
+				layer.WrapTransform[i] = r.f32()
+			}
+			layer.Repeat = r.u8()
+			if r.err != nil {
+				return r.err
+			}
+			if layer.Blend > 3 || layer.BlendSource > 1 || layer.Mode > 4 || layer.Repeat > 3 {
+				return fmt.Errorf("invalid U3D texture layer")
+			}
+			shader.Textures[channel] = layer
+		}
+		d.model.Shaders = append(d.model.Shaders, shader)
+	case 0xffffff51:
+		light := U3DLight{Name: name, Attributes: r.u32(), Kind: r.u8()}
+		if light.Attributes & ^uint32(7) != 0 || light.Kind > 3 {
+			return fmt.Errorf("invalid U3D light parameters")
+		}
+		for index := range light.Color {
+			light.Color[index] = r.f32()
+		}
+		if r.f32() != 1 {
+			return fmt.Errorf("invalid U3D light reserved parameter")
+		}
+		for index := range light.Attenuation {
+			light.Attenuation[index] = r.f32()
+		}
+		light.SpotAngle, light.Intensity = r.f32(), r.f32()
+		d.model.Lights = append(d.model.Lights, light)
+	}
+	return r.err
+}
+
+// checkParents 迭代检查场景父子环路，不递归展开多父节点的实例组合
+// 返回: error 环路或取消错误
+func (d *u3dDecoder) checkParents() error {
+	state := make([]byte, len(d.model.Nodes))
+	type frame struct{ node, parent int }
+	var stack []frame
+	for index := range d.model.Nodes {
+		if state[index] != 0 {
+			continue
+		}
+		stack = append(stack[:0], frame{node: index})
+		state[index] = 1
+		for len(stack) != 0 {
+			if err := d.ctx.Err(); err != nil {
+				return err
+			}
+			current := &stack[len(stack)-1]
+			parents := d.model.Nodes[current.node].Parents
+			if current.parent == len(parents) {
+				state[current.node] = 2
+				stack = stack[:len(stack)-1]
+				continue
+			}
+			parent, exists := d.nodes[parents[current.parent].Name]
+			current.parent++
+			if !exists || state[parent] == 2 {
+				continue
+			}
+			if state[parent] == 1 {
+				return fmt.Errorf("cyclic U3D node parents")
+			}
+			state[parent] = 1
+			stack = append(stack, frame{node: parent})
+		}
+	}
+	return nil
+}

internal/base/threed/u3d_animation.go

@@ -0,0 +1,176 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package threed
+
+import (
+	"context"
+	"fmt"
+	"io"
+)
+
+// U3DAnimation 保存ECMA-363第9.7.3节的动画修饰器，Index为链内位置
+// Attributes的1、2、4、8分别表示启动、锁定根骨骼、单轨播放和动作间平滑过渡
+// TimeScale为整体时间倍率，BlendTime以毫秒计；Motions为空时使用无轨道的默认动作
+type U3DAnimation struct {
+	Index, Attributes    uint32
+	TimeScale, BlendTime float32
+	Motions              []U3DAnimationMotion
+}
+
+// U3DAnimationMotion 保存动画中的动作引用，空名称引用默认动作
+// Attributes的1、2分别表示循环和同步结束，TimeOffset以毫秒计，TimeScale为动作时间倍率
+type U3DAnimationMotion struct {
+	Name                  string
+	Attributes            uint32
+	TimeOffset, TimeScale float32
+}
+
+// animation 读取动画参数及有序动作引用，不在解码时调度或求值
+// 入参: r 字段读取器, name 所属链名, chain 链类型, index 链内位置
+// 返回: error 结构、参数、预算或取消错误
+func (d *u3dDecoder) animation(r *u3dValues, name string, chain int, index uint32) error {
+	animation := U3DAnimation{Index: index, Attributes: r.u32(), TimeScale: r.f32()}
+	count := r.u32()
+	if r.err != nil {
+		return r.err
+	}
+	if len(r.data)-r.pos < 4 || uint64(count) > uint64(len(r.data)-r.pos-4)/14 {
+		return io.ErrUnexpectedEOF
+	}
+	if err := d.reserve(uint64(count), 32); err != nil {
+		return err
+	}
+	if count != 0 {
+		animation.Motions = make([]U3DAnimationMotion, int(count))
+	}
+	for i := range animation.Motions {
+		if i%256 == 0 {
+			if err := d.ctx.Err(); err != nil {
+				return err
+			}
+		}
+		motion := &animation.Motions[i]
+		motion.Name, motion.Attributes = r.text(), r.u32()
+		motion.TimeOffset, motion.TimeScale = r.f32(), r.f32()
+		if r.err != nil {
+			return r.err
+		}
+	}
+	animation.BlendTime = r.f32()
+	if err := r.done(); err != nil {
+		return err
+	}
+	if err := animation.validate(d.ctx); err != nil {
+		return err
+	}
+	if chain == 1 {
+		mesh := &d.meshes[name].mesh
+		mesh.Animations = append(mesh.Animations, animation)
+	} else {
+		node := &d.model.Nodes[d.nodes[name]]
+		node.Animations = append(node.Animations, animation)
+	}
+	return nil
+}
+
+// validate 校验动画属性及有限数值，保留零倍率与反向播放倍率
+// 入参: ctx 取消上下文
+// 返回: error 参数或取消错误
+func (animation U3DAnimation) validate(ctx context.Context) error {
+	if err := ctx.Err(); err != nil {
+		return err
+	}
+	if animation.Index == 0 || animation.Attributes & ^uint32(15) != 0 || !finite(float64(animation.TimeScale)) || !finite(float64(animation.BlendTime)) || animation.BlendTime < 0 {
+		return fmt.Errorf("invalid U3D animation parameters")
+	}
+	for i, motion := range animation.Motions {
+		if i%256 == 0 {
+			if err := ctx.Err(); err != nil {
+				return err
+			}
+		}
+		if motion.Attributes & ^uint32(3) != 0 || !finite(float64(motion.TimeOffset)) || !finite(float64(motion.TimeScale)) {
+			return fmt.Errorf("invalid U3D animation motion parameters")
+		}
+	}
+	return nil
+}
+
+// checkAnimations 校验全部动作引用，仅对接入场景的修饰器检查求值能力
+// 返回: error 引用、能力或取消错误
+func (r *Renderer) checkAnimations() error {
+	check := func(animations []U3DAnimation, evaluate bool) error {
+		for _, animation := range animations {
+			if err := animation.validate(r.ctx); err != nil {
+				return err
+			}
+			for i, motion := range animation.Motions {
+				if i%256 == 0 {
+					if err := r.ctx.Err(); err != nil {
+						return err
+					}
+				}
+				if motion.Name == "" {
+					continue
+				}
+				index, exists := r.motionIndex[motion.Name]
+				if !exists {
+					return fmt.Errorf("missing U3D animation motion %q", motion.Name)
+				}
+				if evaluate && len(animation.Motions) > 1 && len(r.model.Motions[index].Tracks) != 0 {
+					return fmt.Errorf("unsupported U3D animation evaluation for motion %q", motion.Name)
+				}
+			}
+		}
+		return nil
+	}
+	var active []bool
+	if r.connected != nil {
+		if err := r.Reserve(uint64(len(r.model.Meshes)), 1); err != nil {
+			return err
+		}
+		defer func() { r.remaining += uint64(len(active)) }()
+		active = make([]bool, len(r.model.Meshes))
+		for i, node := range r.model.Nodes {
+			if i%256 == 0 {
+				if err := r.ctx.Err(); err != nil {
+					return err
+				}
+			}
+			if r.connected[i] && node.Kind == "Model" {
+				if mesh, exists := r.meshes[node.Resource]; exists {
+					active[mesh] = true
+				}
+			}
+		}
+	}
+	for i := range r.model.Meshes {
+		if err := r.ctx.Err(); err != nil {
+			return err
+		}
+		if err := check(r.model.Meshes[i].Animations, active == nil || active[i]); err != nil {
+			return err
+		}
+	}
+	for i := range r.model.Nodes {
+		if err := r.ctx.Err(); err != nil {
+			return err
+		}
+		if err := check(r.model.Nodes[i].Animations, r.connected == nil || r.connected[i]); err != nil {
+			return err
+		}
+	}
+	return r.ctx.Err()
+}

internal/base/threed/u3d_bits.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package threed
 
 import (
 	"encoding/binary"
@@ -46,6 +46,27 @@ type u3dHistogram struct {
 	total  uint32
 }
 
+// finish 校验压缩块的冲刷字段及结束位置
+// 返回: error 截断、冲刷或多余数据错误
+func (r *u3dBits) finish() error {
+	if r.err != nil {
+		return r.err
+	}
+	if r.pos > uint64(len(r.data))*8 {
+		return io.ErrUnexpectedEOF
+	}
+	if r.u32() != 0 {
+		return fmt.Errorf("invalid U3D compression flush")
+	}
+	if r.err != nil {
+		return r.err
+	}
+	if (r.pos-16+7)/8 != uint64(len(r.data)) {
+		return fmt.Errorf("unexpected U3D compressed block data")
+	}
+	return nil
+}
+
 // take 读取定长字段，失败后不继续推进位置
 // 入参: size 字节数
 // 返回: []byte 字段数据，失败时为空

internal/base/threed/u3d_depth.go

@@ -0,0 +1,75 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package threed
+
+import (
+	"fmt"
+	"math"
+)
+
+// DepthRange 计算可见模型几何的相机深度范围，不为自动裁剪复制顶点
+// 返回: float64 最近深度, float64 最远深度, bool 是否含几何, error 几何或取消错误
+func (r *Renderer) DepthRange() (float64, float64, bool, error) {
+	minimum, maximum := math.Inf(1), math.Inf(-1)
+	for i, instance := range r.scene {
+		if i%256 == 0 {
+			if err := r.ctx.Err(); err != nil {
+				return 0, 0, false, err
+			}
+		}
+		node := r.model.Nodes[instance.node]
+		index, ok := r.meshes[node.Resource]
+		if node.Kind != "Model" || instance.modelVisibility(&node) == 0 || instance.opacity == 0 || !ok {
+			continue
+		}
+		mesh := &r.model.Meshes[index]
+		matrix := r.toCamera.multiply(instance.world)
+		for j := range len(mesh.Faces) + len(mesh.Lines) + len(mesh.Points) {
+			_, corners := mesh.primitive(j)
+			if j%256 == 0 {
+				if err := r.ctx.Err(); err != nil {
+					return 0, 0, false, err
+				}
+			}
+			for _, corner := range corners {
+				if uint64(corner.Position) >= uint64(len(mesh.Positions)) {
+					return 0, 0, false, fmt.Errorf("invalid U3D position index")
+				}
+				p := mesh.Positions[corner.Position]
+				z := matrix[2]*float64(p[0]) + matrix[6]*float64(p[1]) + matrix[10]*float64(p[2]) + matrix[14]
+				if !finite(z) {
+					return 0, 0, false, fmt.Errorf("invalid U3D camera depth")
+				}
+				minimum, maximum = min(minimum, z), max(maximum, z)
+			}
+		}
+	}
+	for i, section := range r.sections {
+		if i%256 == 0 {
+			if err := r.ctx.Err(); err != nil {
+				return 0, 0, false, err
+			}
+		}
+		if section.opacity > 0 {
+			for _, corner := range section.corners {
+				minimum, maximum = min(minimum, corner.point[2]), max(maximum, corner.point[2])
+			}
+		}
+	}
+	if math.IsInf(minimum, 1) {
+		return 0, 0, false, nil
+	}
+	return minimum, maximum, true, nil
+}

internal/base/threed/u3d_finite.go

@@ -0,0 +1,26 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package threed
+
+import (
+	"math"
+)
+
+// finite 判断数值是否有限
+// 入参: value 数值
+// 返回: bool 是否有限
+func finite(value float64) bool {
+	return !math.IsNaN(value) && !math.IsInf(value, 0)
+}

internal/base/threed/u3d_light.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package threed
 
 import (
 	"fmt"
@@ -47,7 +47,7 @@ type u3dRenderStyle struct {
 
 // collectLights 收集本轮根节点下启用的光源实例
 // 返回: error 参数、预算或取消错误
-func (r *u3dRender) collectLights() error {
+func (r *Renderer) collectLights() error {
 	if r.lighting != nil {
 		return nil
 	}
@@ -63,10 +63,13 @@ func (r *u3dRender) collectLights() error {
 			continue
 		}
 		j, ok := r.lightIndex[node.Resource]
-		if !ok {
+		if !ok && node.Resource != "" {
 			continue
 		}
-		light := r.model.Lights[j]
+		light := U3DLight{Attributes: 1, Color: [3]float32{.75, .75, .75}}
+		if ok {
+			light = r.model.Lights[j]
+		}
 		if light.Attributes&1 == 0 {
 			continue
 		}
@@ -98,7 +101,7 @@ func (r *u3dRender) collectLights() error {
 		}
 		if len(r.lights) == cap(r.lights) {
 			capacity := max(8, cap(r.lights)*2)
-			if err := r.reserve(uint64(capacity), 128); err != nil {
+			if err := r.Reserve(uint64(capacity), 128); err != nil {
 				return err
 			}
 			values := make([]u3dRenderLight, len(r.lights), capacity)
@@ -114,7 +117,7 @@ func (r *u3dRender) collectLights() error {
 // overrideLighting 校验并建立替代光源，不依赖模型光源节点
 // 入参: lighting 灯光覆盖，空值保留模型灯光
 // 返回: error 参数、预算或取消错误
-func (r *u3dRender) overrideLighting(lighting *U3DLighting) error {
+func (r *Renderer) overrideLighting(lighting *U3DLighting) error {
 	if lighting == nil {
 		return nil
 	}
@@ -123,7 +126,7 @@ func (r *u3dRender) overrideLighting(lighting *U3DLighting) error {
 			return fmt.Errorf("invalid U3D diffuse offset")
 		}
 	}
-	if err := r.reserve(uint64(len(lighting.Lights)), 128); err != nil {
+	if err := r.Reserve(uint64(len(lighting.Lights)), 128); err != nil {
 		return err
 	}
 	r.lights = make([]u3dRenderLight, len(lighting.Lights))
@@ -152,11 +155,21 @@ func (r *u3dRender) overrideLighting(lighting *U3DLighting) error {
 	return nil
 }
 
-// style 解析着色器与材质，未启用的材质项使用固定默认值
+// shaderPass 返回着色器的绘制轮次位图，默认着色器仅参与第一轮
+// 入参: name 着色器名
+// 返回: uint32 绘制轮次位图
+func (r *Renderer) shaderPass(name string) uint32 {
+	if index, exists := r.shaders[name]; exists {
+		return r.model.Shaders[index].RenderPass
+	}
+	return 1
+}
+
+// style 解析着色器与材质，缺失资源采用ECMA-363第8.4节的默认资源
 // 入参: name 着色器名
 // 返回: u3dRenderStyle 有效绘制参数, error 参数错误
-func (r *u3dRender) style(name string) (u3dRenderStyle, error) {
-	style := u3dRenderStyle{shader: U3DShader{Blend: 0x606, AlphaFunction: 0x617, RenderPass: math.MaxUint32}, ambient: [3]float64{.2, .2, .2}, diffuse: [3]float64{.8, .8, .8}, opacity: 1}
+func (r *Renderer) style(name string) (u3dRenderStyle, error) {
+	style := u3dRenderStyle{shader: U3DShader{Attributes: 1, Blend: 0x606, AlphaFunction: 0x617, RenderPass: 1}, ambient: [3]float64{.75, .75, .75}, opacity: 1}
 	if index, ok := r.shaders[name]; ok {
 		style.shader = r.model.Shaders[index]
 	}
@@ -166,6 +179,7 @@ func (r *u3dRender) style(name string) (u3dRenderStyle, error) {
 	}
 	if index, ok := r.materials[shader.Material]; ok {
 		material := r.model.Materials[index]
+		style.ambient, style.diffuse = [3]float64{.2, .2, .2}, [3]float64{.8, .8, .8}
 		if material.Attributes > 63 {
 			return style, fmt.Errorf("invalid U3D render material")
 		}
@@ -201,7 +215,7 @@ func (r *u3dRender) style(name string) (u3dRenderStyle, error) {
 // shade 按世界坐标计算逐顶点漫反射、镜面与环境光
 // 入参: position 顶点, normal 法线, style 材质, diffuse 顶点漫反射, specular 顶点镜面颜色
 // 返回: [4]float64 直通RGBA, error 参数或取消错误
-func (r *u3dRender) shade(position, normal u3dVector, style u3dRenderStyle, diffuse, specular *[4]float32) ([4]float64, error) {
+func (r *Renderer) shade(position, normal u3dVector, style u3dRenderStyle, diffuse, specular *[4]float32) ([4]float64, error) {
 	color := [4]float64{style.diffuse[0], style.diffuse[1], style.diffuse[2], style.opacity}
 	if style.shader.Attributes&4 != 0 {
 		if diffuse != nil {

internal/base/threed/u3d_line.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package threed
 
 import (
 	"fmt"
@@ -22,7 +22,7 @@ import (
 // drawPrimitives 绘制作者点集及线集，独立着色且不参与面的背向剔除
 // 入参: instance 场景实例, node 模型节点, mesh 属性数组, positions 世界位置, normals 世界法线, pass 绘制轮次, passIndex 轮次索引
 // 返回: error 几何、资源或取消错误
-func (r *u3dRender) drawPrimitives(instance u3dInstance, node *U3DNode, mesh *U3DMesh, positions, normals []u3dVector, pass U3DViewPass, passIndex int) error {
+func (r *Renderer) drawPrimitives(instance u3dInstance, node *U3DNode, mesh *U3DMesh, positions, normals []u3dVector, pass U3DViewPass, passIndex int) error {
 	if r.depthOnly {
 		return nil
 	}
@@ -68,15 +68,13 @@ func (r *u3dRender) drawPrimitives(instance u3dInstance, node *U3DNode, mesh *U3
 			if err := r.ctx.Err(); err != nil {
 				return err
 			}
-			style := u3dRenderStyle{shader: U3DShader{Blend: 0x606, RenderPass: math.MaxUint32}}
+			style := u3dRenderStyle{shader: U3DShader{Blend: 0x606, RenderPass: r.shaderPass(name)}}
 			var err error
 			if shaded {
 				style, err = r.style(name)
 				if err != nil {
 					return err
 				}
-			} else if index, ok := r.shaders[name]; ok {
-				style.shader.RenderPass = r.model.Shaders[index].RenderPass
 			}
 			if style.shader.RenderPass&(1<<passIndex) == 0 {
 				continue
@@ -84,15 +82,22 @@ func (r *u3dRender) drawPrimitives(instance u3dInstance, node *U3DNode, mesh *U3
 			if instance.opacity >= 0 || r.opacity >= 0 {
 				style.shader.Blend = 0x606
 			}
+			textures, err := r.shaderTextures(style.shader)
+			if err != nil {
+				return err
+			}
 			for i, corner := range corners {
+				var normal u3dVector
+				if shaded && !mesh.ExcludeNormals {
+					normal = normals[corner.Normal]
+				}
+				if err := textures.coordinates(&vertices[i], mesh, shading, corner, normal); err != nil {
+					return err
+				}
 				vertices[i].color = [4]float64{r.auxiliaryColor[0], r.auxiliaryColor[1], r.auxiliaryColor[2], 1}
 				if !shaded {
 					continue
 				}
-				var normal u3dVector
-				if !mesh.ExcludeNormals {
-					normal = normals[corner.Normal]
-				}
 				var diffuse, specular *[4]float32
 				if shading.Attributes&1 != 0 {
 					diffuse = &mesh.Diffuse[corner.Diffuse]
@@ -106,8 +111,9 @@ func (r *u3dRender) drawPrimitives(instance u3dInstance, node *U3DNode, mesh *U3
 				}
 				if instance.opacity >= 0 {
 					vertices[i].color[3] = instance.opacity
+					vertices[i].opacityOverride = true
 				}
-				if r.opacity >= 0 {
+				if r.opacity >= 0 && textures == nil {
 					vertices[i].color[3] *= r.opacity
 				}
 			}
@@ -152,7 +158,7 @@ func (r *u3dRender) drawPrimitives(instance u3dInstance, node *U3DNode, mesh *U3
 // lineIntersection 绘制作者线段与剖切面的交点，不绘制共面线段
 // 入参: line 相机空间线段, index 剖切面索引
 // 返回: error 数值、资源或取消错误
-func (r *u3dRender) lineIntersection(line [2]u3dVertex, index int) error {
+func (r *Renderer) lineIntersection(line [2]u3dVertex, index int) error {
 	section := r.sections[index]
 	a, b := u3dPlaneDistance(section.plane, line[0].point), u3dPlaneDistance(section.plane, line[1].point)
 	if !finite(a) || !finite(b) {
@@ -195,7 +201,7 @@ func (r *u3dRender) lineIntersection(line [2]u3dVertex, index int) error {
 
 // frustumPlanes 返回保留正侧的六个相机视锥面
 // 返回: [6][4]float64 近、远、左右及上下平面
-func (r *u3dRender) frustumPlanes() [6][4]float64 {
+func (r *Renderer) frustumPlanes() [6][4]float64 {
 	w, h := r.viewport[2]/2, r.viewport[3]/2
 	planes := [6][4]float64{{0, 0, 1, -r.camera.Near}, {0, 0, -1, r.camera.Far}, {r.camera.ScaleX, 0, 0, w + r.camera.ShiftX}, {-r.camera.ScaleX, 0, 0, w - r.camera.ShiftX}, {0, r.camera.ScaleY, 0, h - r.camera.ShiftY}, {0, -r.camera.ScaleY, 0, h + r.camera.ShiftY}}
 	if r.camera.Perspective {
@@ -226,7 +232,7 @@ func u3dClipFraction(a, b float64) float64 {
 	return a / (a + b)
 }
 
-// u3dInterpolate 在相机空间插值坐标与未预乘颜色
+// u3dInterpolate 在相机空间插值位置、颜色与纹理输入
 // 入参: a 起点, b 终点, t 比例
 // 返回: u3dVertex 插值顶点
 func u3dInterpolate(a, b u3dVertex, t float64) u3dVertex {
@@ -237,13 +243,25 @@ func u3dInterpolate(a, b u3dVertex, t float64) u3dVertex {
 	for i := range result.color {
 		result.color[i] = a.color[i]*(1-t) + b.color[i]*t
 	}
+	result.textureMask = a.textureMask | b.textureMask
+	result.opacityOverride = a.opacityOverride
+	if result.textureMask != 0 {
+		for layer := range result.texture {
+			if result.textureMask&(1<<layer) == 0 {
+				continue
+			}
+			for c := range result.texture[layer] {
+				result.texture[layer][c] = a.texture[layer][c]*(1-t) + b.texture[layer][c]*t
+			}
+		}
+	}
 	return result
 }
 
 // sectionIntersection 绘制原三角面与指定剖切面的交线，其他剖切面仍参与裁剪
 // 入参: triangle 原三角面, index 剖切面索引
 // 返回: error 数值、资源或取消错误
-func (r *u3dRender) sectionIntersection(triangle [3]u3dVertex, index int) error {
+func (r *Renderer) sectionIntersection(triangle [3]u3dVertex, index int) error {
 	if err := r.ctx.Err(); err != nil {
 		return err
 	}
@@ -334,7 +352,7 @@ func u3dClipLine(a, b *u3dVertex, plane [4]float64) (bool, error) {
 // rasterSectionLine 绘制单像素不透明交线，透视深度使用倒数插值
 // 入参: a 已裁剪起点, b 已裁剪终点, rgb 交线颜色, normal 原面法线, origin 原面上一点
 // 返回: error 数值、资源或取消错误
-func (r *u3dRender) rasterSectionLine(a, b u3dVertex, rgb [3]float64, normal, origin u3dVector) error {
+func (r *Renderer) rasterSectionLine(a, b u3dVertex, rgb [3]float64, normal, origin u3dVector) error {
 	a.color = [4]float64{rgb[0], rgb[1], rgb[2], 1}
 	b.color = a.color
 	return r.rasterLine(a, b, normal, origin, U3DShader{Blend: 0x606}, U3DViewPass{})
@@ -343,7 +361,11 @@ func (r *u3dRender) rasterSectionLine(a, b u3dVertex, rgb [3]float64, normal, or
 // rasterLine 绘制单像素线段，颜色与深度按透视插值，面深度偏移防止自身遮挡
 // 入参: a 已裁剪起点, b 已裁剪终点, normal 面法线, origin 面上点, shader 着色器, pass 绘制轮次
 // 返回: error 数值、资源或取消错误
-func (r *u3dRender) rasterLine(a, b u3dVertex, normal, origin u3dVector, shader U3DShader, pass U3DViewPass) error {
+func (r *Renderer) rasterLine(a, b u3dVertex, normal, origin u3dVector, shader U3DShader, pass U3DViewPass) error {
+	textures, err := r.shaderTextures(shader)
+	if err != nil {
+		return err
+	}
 	cx := r.viewport[0] + r.viewport[2]/2 + r.camera.ShiftX
 	cy := r.viewport[1] + r.viewport[3]/2 + r.camera.ShiftY
 	planes := [4][4]float64{{r.camera.ScaleX, 0, 0, cx}, {-r.camera.ScaleX, 0, 0, float64(r.output.Rect.Dx()) - cx}, {0, -r.camera.ScaleY, 0, cy}, {0, r.camera.ScaleY, 0, float64(r.output.Rect.Dy()) - cy}}
@@ -413,6 +435,9 @@ func (r *u3dRender) rasterLine(a, b u3dVertex, normal, origin u3dVector, shader
 		depth -= 8 * math.Abs(depth-math.Nextafter(depth, math.Inf(-1)))
 		if depth <= r.frame[pixel].depth {
 			vertex := u3dInterpolate(a, b, weight)
+			if err := r.textureColor(textures, &vertex.color, &vertex.texture, vertex.point, vertex.opacityOverride); err != nil {
+				return err
+			}
 			visible, err := u3dFragmentColor(&vertex.color, vertex.point, &shader, &pass)
 			if err != nil {
 				return err

internal/base/threed/u3d_lineset.go

@@ -12,11 +12,10 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package threed
 
 import (
 	"fmt"
-	"io"
 )
 
 // U3D线集增量编码的算术编码上下文
@@ -94,9 +93,11 @@ func (d *u3dDecoder) primitiveDeclaration(r *u3dValues, name string, points bool
 			return fmt.Errorf("invalid U3D reserved primitive parameter")
 		}
 	}
-	if r.u32() != 0 {
-		return fmt.Errorf("unsupported U3D skeletal primitive set")
+	bones, err := d.skeleton(r)
+	if err != nil {
+		return err
 	}
+	decl.mesh.Bones = bones
 	if err := r.done(); err != nil {
 		return err
 	}
@@ -210,11 +211,11 @@ func (s *u3dLineState) accumulateCorners(mesh *U3DMesh, shadingIndex uint32, cor
 }
 
 // value 按指定上下文和位宽读取点集或线集字段
-// 入参: context 压缩上下文, small 是否为8位字段
+// 入参: ctx 压缩上下文, small 是否为8位字段
 // 返回: uint32 字段值
-func (r *u3dLineReader) value(context int, small bool) uint32 {
+func (r *u3dLineReader) value(ctx int, small bool) uint32 {
 	if r.bits != nil {
-		return r.bits.dynamicValue(&r.hist[context], small)
+		return r.bits.dynamicValue(&r.hist[ctx], small)
 	}
 	if small {
 		return uint32(r.values.u8())
@@ -444,17 +445,8 @@ func (d *u3dDecoder) primitiveContinuation(r *u3dValues, name string, points boo
 		}
 	}
 	if b := reader.bits; b != nil {
-		if b.pos > uint64(len(b.data))*8 {
-			return io.ErrUnexpectedEOF
-		}
-		if b.u32() != 0 {
-			return fmt.Errorf("invalid U3D primitive compression flush")
-		}
-		if b.err != nil {
-			return b.err
-		}
-		if (b.pos-16+7)/8 != uint64(len(b.data)) {
-			return fmt.Errorf("unexpected U3D primitive compressed data")
+		if err := b.finish(); err != nil {
+			return err
 		}
 		r.pos = len(r.data)
 	}

internal/base/threed/u3d_mapping.go

@@ -0,0 +1,141 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package threed
+
+import (
+	"fmt"
+	"math"
+)
+
+// u3dTextureInverse 计算包裹变换的逆矩阵，保留非仿射齐次分量
+// 入参: matrix 按列排列的包裹变换
+// 返回: [16]float64 逆矩阵, error 奇异矩阵或非有限结果
+func u3dTextureInverse(matrix [16]float32) ([16]float64, error) {
+	var rows [4][8]float64
+	for row := range 4 {
+		for col := range 4 {
+			rows[row][col] = float64(matrix[col*4+row])
+			if !finite(rows[row][col]) {
+				return [16]float64{}, fmt.Errorf("invalid U3D texture wrap transform")
+			}
+		}
+		rows[row][row+4] = 1
+	}
+	for col := range 4 {
+		pivot := col
+		for row := col + 1; row < 4; row++ {
+			if math.Abs(rows[row][col]) > math.Abs(rows[pivot][col]) {
+				pivot = row
+			}
+		}
+		if rows[pivot][col] == 0 {
+			return [16]float64{}, fmt.Errorf("singular U3D texture wrap transform")
+		}
+		rows[col], rows[pivot] = rows[pivot], rows[col]
+		divisor := rows[col][col]
+		for i := range 8 {
+			rows[col][i] /= divisor
+		}
+		for row := range 4 {
+			if row == col {
+				continue
+			}
+			factor := rows[row][col]
+			for i := range 8 {
+				rows[row][i] -= factor * rows[col][i]
+			}
+		}
+	}
+	var result [16]float64
+	for row := range 4 {
+		for col := range 4 {
+			value := rows[row][col+4]
+			if !finite(value) {
+				return [16]float64{}, fmt.Errorf("invalid U3D inverse texture wrap transform")
+			}
+			result[col*4+row] = value
+		}
+	}
+	return result, nil
+}
+
+// generated 将插值后的位置或法线映射到纹理，再应用纹理变换
+// 经线未定义时取0，球心纬度取1/2，反射方向奇点取图像中心
+// 入参: channel 通道索引, input 模型位置或相机法线, position 相机空间位置
+// 返回: [3]float64 齐次纹理坐标, error 非有限值或无效投影
+func (s *u3dTextureSet) generated(channel int, input [3]float64, position u3dVector) ([3]float64, error) {
+	layer := s.layers[channel]
+	for _, value := range input {
+		if !finite(value) {
+			return [3]float64{}, fmt.Errorf("invalid U3D texture mapping input")
+		}
+	}
+	uv := [4]float64{0, 0, 0, 1}
+	if layer.Mode == 4 {
+		incident := u3dVector{0, 0, 1}
+		if s.perspective {
+			incident = position.unit()
+		}
+		normal := u3dVector(input).unit()
+		factor := 2 * normal.dot(incident)
+		reflected := incident.sub(u3dVector{factor * normal[0], factor * normal[1], factor * normal[2]})
+		denominator := 2 * math.Hypot(math.Hypot(reflected[0], reflected[1]), 1-reflected[2])
+		uv[0], uv[1] = .5, .5
+		if denominator != 0 {
+			uv[0] += reflected[0] / denominator
+			uv[1] -= reflected[1] / denominator
+		}
+	} else {
+		var point [4]float64
+		for row := range 4 {
+			point[row] = s.wrap[channel][12+row]
+			for col, value := range input {
+				point[row] += s.wrap[channel][col*4+row] * value
+			}
+		}
+		for i := range 3 {
+			point[i] /= point[3]
+			if !finite(point[i]) {
+				return [3]float64{}, fmt.Errorf("invalid U3D texture wrap projection")
+			}
+		}
+		switch layer.Mode {
+		case 1:
+			uv[0], uv[1] = point[0], point[1]
+		case 2, 3:
+			if point[0] != 0 || point[1] != 0 {
+				uv[0] = math.Atan2(point[1], point[0]) / (2 * math.Pi)
+				if uv[0] < 0 {
+					uv[0]++
+				}
+			}
+			uv[1] = point[2]
+			if layer.Mode == 3 {
+				direction := (u3dVector{point[0], point[1], point[2]}).unit()
+				uv[1] = math.Acos(min(1, max(-1, direction[2]))) / math.Pi
+			}
+		}
+	}
+	var result [3]float64
+	for component, row := range [3]int{0, 1, 3} {
+		for col, value := range uv {
+			result[component] += float64(layer.Transform[col*4+row]) * value
+		}
+		if !finite(result[component]) {
+			return [3]float64{}, fmt.Errorf("invalid U3D generated texture coordinate")
+		}
+	}
+	return result, nil
+}

internal/base/threed/u3d_mesh.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package threed
 
 import (
 	"fmt"
@@ -29,6 +29,9 @@ type U3DMesh struct {
 	Faces                                       []U3DFace
 	Lines                                       []U3DLine
 	Points                                      []U3DPoint
+	Bones                                       []U3DBone
+	BoneWeights                                 []U3DBoneWeights
+	Animations                                  []U3DAnimation
 	Quality                                     [3]uint32
 	InverseQuantization                         [5]float32
 	NormalCrease, NormalUpdate, NormalTolerance float32
@@ -76,7 +79,7 @@ type u3dMeshDeclaration struct {
 
 // primitive 访问三角面、线段或点的着色编号和角点，不复制属性数组
 // 入参: index 图元下标，依次为三角面、线段和点
-// 返回: uint32 着色编号, []U3DCorner 只读角点
+// 返回: uint32 着色编号, []U3DCorner 原数组中的角点切片
 func (m *U3DMesh) primitive(index int) (uint32, []U3DCorner) {
 	if index < len(m.Faces) {
 		return m.Faces[index].Shading, m.Faces[index].Corners[:]
@@ -116,16 +119,20 @@ func (d *u3dDecoder) meshDeclaration(r *u3dValues, name string) error {
 		decl.mesh.InverseQuantization[index] = r.f32()
 	}
 	decl.mesh.NormalCrease, decl.mesh.NormalUpdate, decl.mesh.NormalTolerance = r.f32(), r.f32(), r.f32()
-	bones := r.u32()
 	if r.err != nil {
 		return r.err
 	}
 	if minimum > maximum || maximum != decl.counts[1] {
 		return fmt.Errorf("invalid U3D mesh resolution")
 	}
-	if minimum != maximum || bones != 0 {
-		return fmt.Errorf("unsupported U3D progressive or skeletal mesh")
+	if minimum != maximum {
+		return fmt.Errorf("unsupported U3D progressive mesh")
 	}
+	bones, err := d.skeleton(r)
+	if err != nil {
+		return err
+	}
+	decl.mesh.Bones = bones
 	if minimum == 0 {
 		for _, count := range decl.counts[:6] {
 			if count != 0 {
@@ -247,10 +254,16 @@ func (d *u3dDecoder) baseMesh(r *u3dValues, name string) error {
 	var histogram u3dHistogram
 	var compressed *u3dBits
 	if !d.plain && counts[0] != 0 {
-		if err := d.reserve(1, 1<<20); err != nil {
-			return err
-		}
 		compressed = newU3DBits(r.data[r.pos:])
+		var charged uint64
+		compressed.reserve = func(count, size uint64) error {
+			if err := d.reserve(count, size); err != nil {
+				return err
+			}
+			charged += count * size
+			return nil
+		}
+		defer func() { d.remaining += charged }()
 	}
 	readIndex := func(count uint32) (uint32, error) {
 		var value uint32
@@ -321,17 +334,8 @@ func (d *u3dDecoder) baseMesh(r *u3dValues, name string) error {
 		}
 	}
 	if compressed != nil {
-		if compressed.pos > uint64(len(compressed.data))*8 {
-			return io.ErrUnexpectedEOF
-		}
-		if compressed.u32() != 0 {
-			return fmt.Errorf("invalid U3D compression flush")
-		}
-		if compressed.err != nil {
-			return compressed.err
-		}
-		if (compressed.pos-16+7)/8 != uint64(len(compressed.data)) {
-			return fmt.Errorf("unexpected U3D compressed block data: decoded %d bits, stored %d bytes", compressed.pos-16, len(compressed.data))
+		if err := compressed.finish(); err != nil {
+			return err
 		}
 		r.pos = len(r.data)
 	}

internal/base/threed/u3d_mode.go

@@ -12,16 +12,13 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package threed
 
 import (
 	"fmt"
 	"math"
 )
 
-// U3DRenderMode 定义静态几何的呈现方式，边线和顶点使用单像素覆盖
-type U3DRenderMode uint8
-
 const (
 	U3DRenderSolid              U3DRenderMode = iota // 实体
 	U3DRenderSolidWireframe                          // 实体线框
@@ -38,18 +35,29 @@ const (
 	U3DRenderShadedIllustration                      // 着色插图
 )
 
+// U3DRenderMode 定义静态几何的呈现方式，边线和顶点使用单像素覆盖
+type U3DRenderMode uint8
+
 // u3dPrimitiveKey 区分共享点线的颜色及混合状态，避免透明边点重复叠加
 type u3dPrimitiveKey struct {
-	a, b      u3dVertex
+	a, b      [7]float64
 	blend     uint32
 	function  uint32
 	reference float32
 }
 
+// u3dTexturedPrimitiveKey 额外区分纹理坐标及纹理层，不扩大普通边点缓存
+type u3dTexturedPrimitiveKey struct {
+	base            u3dPrimitiveKey
+	coordinates     [2][8][3]float64
+	layers          [8]*U3DTextureLayer
+	opacityOverride bool
+}
+
 // uniquePrimitive 在当前网格内去重着色边点，缓存按条目计入绘制预算
 // 入参: a 起点或顶点, b 终点或相同顶点, shader 着色器
 // 返回: bool 是否首次绘制, error 预算或取消错误
-func (r *u3dRender) uniquePrimitive(a, b u3dVertex, shader U3DShader) (bool, error) {
+func (r *Renderer) uniquePrimitive(a, b u3dVertex, shader U3DShader) (bool, error) {
 	if r.primitives == nil {
 		return true, nil
 	}
@@ -59,18 +67,33 @@ func (r *u3dRender) uniquePrimitive(a, b u3dVertex, shader U3DShader) (bool, err
 		if left[i] != right[i] {
 			if left[i] > right[i] {
 				a, b = b, a
+				left, right = right, left
 			}
 			break
 		}
 	}
-	key := u3dPrimitiveKey{a: a, b: b, blend: shader.Blend}
+	key := u3dPrimitiveKey{a: left, b: right, blend: shader.Blend}
 	if shader.Attributes&2 != 0 {
 		key.function, key.reference = shader.AlphaFunction, shader.AlphaReference
 	}
+	if shader.Textures != ([8]*U3DTextureLayer{}) {
+		textured := u3dTexturedPrimitiveKey{base: key, coordinates: [2][8][3]float64{a.texture, b.texture}, layers: shader.Textures, opacityOverride: a.opacityOverride}
+		if _, ok := r.texturedPrimitives[textured]; ok {
+			return false, nil
+		}
+		if err := r.Reserve(1, 1024); err != nil {
+			return false, err
+		}
+		if r.texturedPrimitives == nil {
+			r.texturedPrimitives = make(map[u3dTexturedPrimitiveKey]struct{})
+		}
+		r.texturedPrimitives[textured] = struct{}{}
+		return true, nil
+	}
 	if _, ok := r.primitives[key]; ok {
 		return false, nil
 	}
-	if err := r.reserve(1, 512); err != nil {
+	if err := r.Reserve(1, 512); err != nil {
 		return false, err
 	}
 	r.primitives[key] = struct{}{}
@@ -92,7 +115,7 @@ func (mode U3DRenderMode) silhouette() bool {
 // modeTriangle 根据当前模式绘制原三角面、原始边或顶点，不为裁剪边界生成网格边
 // 入参: triangle 相机空间顶点, shader 着色器, pass 绘制轮次
 // 返回: error 数值、资源或取消错误
-func (r *u3dRender) modeTriangle(triangle [3]u3dVertex, shader U3DShader, pass U3DViewPass) error {
+func (r *Renderer) modeTriangle(triangle [3]u3dVertex, shader U3DShader, pass U3DViewPass) error {
 	if r.depthOnly || r.mode == U3DRenderSolid || r.mode.silhouette() {
 		return r.sectionTriangle(triangle, shader, pass)
 	}
@@ -148,7 +171,7 @@ func (r *u3dRender) modeTriangle(triangle [3]u3dVertex, shader U3DShader, pass U
 // modeLine 对原始网格边应用剖切与视锥裁剪，再按像素深度绘制
 // 入参: a 起点, b 终点, normal 面法线, origin 面上点, shader 着色器, pass 绘制轮次
 // 返回: error 数值、资源或取消错误
-func (r *u3dRender) modeLine(a, b u3dVertex, normal, origin u3dVector, shader U3DShader, pass U3DViewPass) error {
+func (r *Renderer) modeLine(a, b u3dVertex, normal, origin u3dVector, shader U3DShader, pass U3DViewPass) error {
 	for i, section := range r.sections {
 		if i%256 == 0 {
 			if err := r.ctx.Err(); err != nil {
@@ -175,7 +198,7 @@ func (r *u3dRender) modeLine(a, b u3dVertex, normal, origin u3dVector, shader U3
 // modePoint 绘制原始顶点，不在裁剪边界补充顶点
 // 入参: vertex 顶点, shader 着色器, pass 绘制轮次
 // 返回: error 数值、资源或取消错误
-func (r *u3dRender) modePoint(vertex u3dVertex, shader U3DShader, pass U3DViewPass) error {
+func (r *Renderer) modePoint(vertex u3dVertex, shader U3DShader, pass U3DViewPass) error {
 	if err := r.ctx.Err(); err != nil {
 		return err
 	}
@@ -221,6 +244,13 @@ func (r *u3dRender) modePoint(vertex u3dVertex, shader U3DShader, pass U3DViewPa
 	if vertex.point[2] > r.frame[pixel].depth {
 		return nil
 	}
+	textures, err := r.shaderTextures(shader)
+	if err != nil {
+		return err
+	}
+	if err := r.textureColor(textures, &vertex.color, &vertex.texture, vertex.point, vertex.opacityOverride); err != nil {
+		return err
+	}
 	visible, err := u3dFragmentColor(&vertex.color, vertex.point, &shader, &pass)
 	if err != nil || !visible {
 		return err
@@ -232,7 +262,7 @@ func (r *u3dRender) modePoint(vertex u3dVertex, shader U3DShader, pass U3DViewPa
 // drawBounds 在模型局部空间计算包围盒，再应用实例变换，不以世界坐标轴重建包围盒
 // 入参: instance 场景实例, node 模型节点, mesh 网格, pass 绘制轮次, passIndex 轮次索引
 // 返回: error 几何、数值、预算或取消错误
-func (r *u3dRender) drawBounds(instance u3dInstance, node *U3DNode, mesh *U3DMesh, pass U3DViewPass, passIndex int) error {
+func (r *Renderer) drawBounds(instance u3dInstance, node *U3DNode, mesh *U3DMesh, pass U3DViewPass, passIndex int) error {
 	minimum := u3dVector{math.Inf(1), math.Inf(1), math.Inf(1)}
 	maximum := u3dVector{math.Inf(-1), math.Inf(-1), math.Inf(-1)}
 	visible := false
@@ -251,11 +281,10 @@ func (r *u3dRender) drawBounds(instance u3dInstance, node *U3DNode, mesh *U3DMes
 			}
 		}
 		if uint64(shading) >= uint64(len(shaders)) {
-			visible = true
+			visible = visible || passIndex == 0
 		} else if !visible {
 			for _, name := range shaders[shading] {
-				index, ok := r.shaders[name]
-				if !ok || r.model.Shaders[index].RenderPass&(1<<passIndex) != 0 {
+				if r.shaderPass(name)&(1<<passIndex) != 0 {
 					visible = true
 					break
 				}

internal/base/threed/u3d_motion.go

@@ -0,0 +1,188 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package threed
+
+import (
+	"fmt"
+	"math"
+)
+
+// U3DMotion 保存骨骼或节点动作轨道，解码不执行动画
+type U3DMotion struct {
+	Name                                                 string
+	TimeInverseQuantization, RotationInverseQuantization float32
+	Tracks                                               []U3DMotionTrack
+}
+
+// U3DMotionTrack 保存命名轨道及其关键帧，保持文件中的时间与帧次序
+type U3DMotionTrack struct {
+	Name                                                      string
+	DisplacementInverseQuantization, ScaleInverseQuantization float32
+	Frames                                                    []U3DKeyFrame
+}
+
+// U3DKeyFrame 保存关键帧时间及相对父项的变换，Rotation按W、X、Y、Z排列
+type U3DKeyFrame struct {
+	Time                float32
+	Displacement, Scale [3]float32
+	Rotation            [4]float32
+}
+
+// motion 读取ECMA-363第9.8.6节的动作资源，首尾帧保留未量化数值
+// 入参: values 字段读取器, name 资源名
+// 返回: error 结构、数值、预算或取消错误
+func (d *u3dDecoder) motion(values *u3dValues, name string) error {
+	r := u3dResourceReader{values: values, decoder: d}
+	defer r.release()
+	count := r.u32()
+	motion := U3DMotion{Name: name, TimeInverseQuantization: r.f32(), RotationInverseQuantization: r.f32()}
+	if err := r.err(); err != nil {
+		return err
+	}
+	if motion.TimeInverseQuantization < 0 || motion.RotationInverseQuantization < 0 {
+		return fmt.Errorf("invalid U3D motion quantization")
+	}
+	if err := d.reserve(uint64(count), 48); err != nil {
+		return err
+	}
+	motion.Tracks = make([]U3DMotionTrack, int(count))
+	for index := range motion.Tracks {
+		if err := d.ctx.Err(); err != nil {
+			return err
+		}
+		track := &motion.Tracks[index]
+		track.Name = r.text()
+		frames := r.u32()
+		track.DisplacementInverseQuantization, track.ScaleInverseQuantization = r.f32(), r.f32()
+		if err := r.err(); err != nil {
+			return err
+		}
+		if track.DisplacementInverseQuantization < 0 || track.ScaleInverseQuantization < 0 {
+			return fmt.Errorf("invalid U3D motion track quantization")
+		}
+		if err := d.reserve(uint64(frames), 44); err != nil {
+			return err
+		}
+		track.Frames = make([]U3DKeyFrame, int(frames))
+		for i := range track.Frames {
+			if i%256 == 0 {
+				if err := d.ctx.Err(); err != nil {
+					return err
+				}
+			}
+			frame := &track.Frames[i]
+			if i == 0 || i == len(track.Frames)-1 {
+				frame.Time = r.f32()
+				for component := range frame.Displacement {
+					frame.Displacement[component] = r.f32()
+				}
+				for component := range frame.Rotation {
+					frame.Rotation[component] = r.f32()
+				}
+				for component := range frame.Scale {
+					frame.Scale[component] = r.f32()
+				}
+			} else if err := r.motionFrame(frame, track.Frames[i-1], &motion, track); err != nil {
+				return err
+			}
+			if err := r.err(); err != nil {
+				return err
+			}
+		}
+	}
+	if err := r.done(); err != nil {
+		return err
+	}
+	d.model.Motions = append(d.model.Motions, motion)
+	return nil
+}
+
+// motionFrame 按前一帧预测时间、位移和缩放，并右乘旋转差分四元数
+// 入参: frame 目标帧, previous 前一帧, motion 动作量化参数, track 轨道量化参数
+// 返回: error 符号、数值或读取错误
+func (r *u3dResourceReader) motionFrame(frame *U3DKeyFrame, previous U3DKeyFrame, motion *U3DMotion, track *U3DMotionTrack) error {
+	time, err := r.motionDifference([]float32{previous.Time}, motion.TimeInverseQuantization, 0)
+	if err != nil {
+		return err
+	}
+	frame.Time = time[0]
+	position, err := r.motionDifference(previous.Displacement[:], track.DisplacementInverseQuantization, 2)
+	if err != nil {
+		return err
+	}
+	copy(frame.Displacement[:], position[:])
+	signs := r.value(4, true)
+	if signs > 15 {
+		return fmt.Errorf("invalid U3D motion rotation signs")
+	}
+	var difference [4]float64
+	var squared float64
+	for component := 1; component < 4; component++ {
+		value := float64(r.value(5, false)) * float64(motion.RotationInverseQuantization)
+		if signs&(1<<component) != 0 {
+			value = -value
+		}
+		difference[component] = value
+		squared += value * value
+	}
+	if err := r.err(); err != nil {
+		return err
+	}
+	if squared > 1 {
+		return fmt.Errorf("invalid U3D motion rotation difference")
+	}
+	difference[0] = math.Sqrt(1 - squared)
+	if signs&1 != 0 {
+		difference[0] = -difference[0]
+	}
+	p := previous.Rotation
+	w, x, y, z := float64(p[0]), float64(p[1]), float64(p[2]), float64(p[3])
+	a, b, c, e := difference[0], difference[1], difference[2], difference[3]
+	frame.Rotation = [4]float32{
+		float32(w*a - x*b - y*c - z*e),
+		float32(w*b + x*a + y*e - z*c),
+		float32(w*c - x*e + y*a + z*b),
+		float32(w*e + x*c - y*b + z*a),
+	}
+	for _, value := range frame.Rotation {
+		if !finite(float64(value)) {
+			return fmt.Errorf("invalid U3D reconstructed rotation")
+		}
+	}
+	scale, err := r.motionDifference(previous.Scale[:], track.ScaleInverseQuantization, 6)
+	copy(frame.Scale[:], scale[:])
+	return err
+}
+
+// motionDifference 用共享幅值上下文恢复一至三个差分分量
+// 入参: previous 前一帧分量, scale 逆量化系数, ctx 符号上下文，下一项为幅值上下文
+// 返回: [3]float32 重建分量, error 符号、数值或读取错误
+func (r *u3dResourceReader) motionDifference(previous []float32, scale float32, ctx int) (values [3]float32, err error) {
+	signs := r.value(ctx, true)
+	if signs >= 1<<len(previous) {
+		return values, fmt.Errorf("invalid U3D motion difference signs")
+	}
+	for index, prior := range previous {
+		difference := float64(r.value(ctx+1, false)) * float64(scale)
+		if signs&(1<<index) != 0 {
+			difference = -difference
+		}
+		values[index] = float32(float64(prior) + difference)
+		if !finite(float64(values[index])) {
+			return values, fmt.Errorf("invalid U3D reconstructed motion value")
+		}
+	}
+	return values, r.err()
+}

internal/base/threed/u3d_outline.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package ofdgo
+package threed
 
 import (
 	"fmt"
@@ -39,7 +39,7 @@ type u3dOutlineEdge struct {
 // outlineFace 收集当前绘制轮次中的原始网格边，正面法线在同一半圆内取角度极值
 // 入参: outline 共享边索引, world 世界坐标, vertices 相机顶点, front 是否正面, visible 是否绘制面, shaders 着色列表, passIndex 轮次
 // 返回: error 数值、预算或取消错误
-func (r *u3dRender) outlineFace(outline *u3dOutline, world [3]u3dVector, vertices [3]u3dVertex, front, visible bool, shaders []string, passIndex int) error {
+func (r *Renderer) outlineFace(outline *u3dOutline, world [3]u3dVector, vertices [3]u3dVertex, front, visible bool, shaders []string, passIndex int) error {
 	active := false
 	for i, name := range shaders {
 		if i%128 == 0 {
@@ -47,8 +47,7 @@ func (r *u3dRender) outlineFace(outline *u3dOutline, world [3]u3dVector, vertice
 				return err
 			}
 		}
-		index, ok := r.shaders[name]
-		if !ok || r.model.Shaders[index].RenderPass&(1<<passIndex) != 0 {
+		if r.shaderPass(name)&(1<<passIndex) != 0 {
 			active = true
 			break
 		}
@@ -76,7 +75,7 @@ func (r *u3dRender) outlineFace(outline *u3dOutline, world [3]u3dVector, vertice
 		key := [2]u3dVector{a, b}
 		index, exists := outline.index[key]
 		if !exists {
-			if err := r.reserve(1, 1024); err != nil {
+			if err := r.Reserve(1, 1024); err != nil {
 				return err
 			}
 			index = len(outline.edges)
@@ -117,7 +116,7 @@ func (r *u3dRender) outlineFace(outline *u3dOutline, world [3]u3dVector, vertice
 // drawOutline 绘制外缘、正背面交界和达到夹角的共享边，沿用像素深度去除遮挡
 // 入参: outline 共享边索引, pass 绘制轮次
 // 返回: error 数值、资源或取消错误
-func (r *u3dRender) drawOutline(outline *u3dOutline, pass U3DViewPass) error {
+func (r *Renderer) drawOutline(outline *u3dOutline, pass U3DViewPass) error {
 	shader := U3DShader{Blend: 0x606}
 	color := [4]float64{r.auxiliaryColor[0], r.auxiliaryColor[1], r.auxiliaryColor[2], 1}
 	for i, edge := range outline.edges {