feat(正式发布): 实现了OFD渲染和导出为PDF、图片、矢量图等

ofdgo.go

@@ -0,0 +1,116 @@
+// Copyright 2025 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 ofdgo 首款原生、全平台兼容的纯 Go 语言 OFD 渲染库
+package ofdgo
+
+import (
+	"archive/zip"
+	"io"
+	"io/fs"
+
+	"github.com/tdewolff/canvas"
+)
+
+// Open 打开OFD文件
+// 入参: path 文件路径
+// 返回: *Reader 阅读器实例, error 错误信息
+func Open(path string) (*Reader, error) {
+	r, err := zip.OpenReader(path)
+	if err != nil {
+		return nil, err
+	}
+	reader := &Reader{
+		Path:   path,
+		Zip:    &r.Reader,
+		Closer: r,
+	}
+	if err := reader.initRoot(); err != nil {
+		reader.Close()
+		return nil, err
+	}
+	return reader, nil
+}
+
+// NewReader 从流创建一个 OFD 阅读器
+// 入参: r IO读取器, size 数据大小
+// 返回: *Reader 阅读器实例, error 错误信息
+func NewReader(r io.ReaderAt, size int64) (*Reader, error) {
+	zr, err := zip.NewReader(r, size)
+	if err != nil {
+		return nil, err
+	}
+	reader := &Reader{
+		Zip: zr,
+	}
+	if err := reader.initRoot(); err != nil {
+		return nil, err
+	}
+	return reader, nil
+}
+
+// NewRenderer 创建渲染器
+// 入参: reader 阅读器, opts 渲染选项
+// 返回: *Renderer 渲染器实例
+func NewRenderer(reader *Reader, opts ...RendererOption) *Renderer {
+	r := &Renderer{
+		Reader:     reader,
+		DPI:        300.0,
+		DrawParams: reader.drawParamCache,
+		FontMap:    make(map[string]*canvas.FontFamily),
+	}
+	for _, opt := range opts {
+		opt(r)
+	}
+	r.initCommon()
+	return r
+}
+
+// WithDPI 设置渲染DPI
+// 入参: dpi DPI值
+// 返回: RendererOption 渲染选项
+func WithDPI(dpi float64) RendererOption {
+	return func(r *Renderer) {
+		r.DPI = dpi
+	}
+}
+
+// WithFontDirs 设置外部字体查找目录
+// 入参: dirs 字体目录列表
+// 返回: RendererOption 渲染选项
+func WithFontDirs(dirs ...string) RendererOption {
+	return func(r *Renderer) {
+		r.fontDirs = append(r.fontDirs, dirs...)
+	}
+}
+
+// WithFontFS 设置外部字体文件系统
+// 入参: fs 字体文件系统
+// 返回: RendererOption 渲染选项
+func WithFontFS(fs ...fs.FS) RendererOption {
+	return func(r *Renderer) {
+		r.fontFS = append(r.fontFS, fs...)
+	}
+}
+
+// PageCount 获取文档总页数
+// 入参: reader 阅读器
+// 返回: int 页数
+func PageCount(reader *Reader) int {
+	doc, _ := reader.Doc()
+	if doc == nil {
+		return 0
+	}
+	return len(doc.Pages.Page)
+}