feat(转换能力): 完善PDF转换与字体回退

assets/webui/ofdgo.js

@@ -4085,8 +4085,18 @@ async function loadDocumentDetails(openSeq) {
 			const info = await callWASM("ofdgoDocumentInfo", true);
 			if (openSeq !== state.openSeq) return;
 			if (!info.detailsPending) {
+				const knownFonts = new Set((state.doc.fonts || []).map(font => font.id));
+				const missingFonts = info.fonts?.some(font => font.used > 0 && font.status === "missing" && !knownFonts.has(font.id));
 				Object.assign(state.doc, info, { detailsPending: false, detailsError: "" });
 				renderMeta();
+				if (missingFonts && fontManager.permission === "granted" && !state.editorInfo && !document.body.hasAttribute("aria-busy")) {
+					setBusy(true);
+					try {
+						if (await autoLoadDocumentLocalFonts(openSeq) && openSeq === state.openSeq) await applyFontChange();
+					} finally {
+						if (openSeq === state.openSeq) setBusy(false);
+					}
+				}
 				return;
 			}
 		}

go.mod

@@ -9,7 +9,7 @@ require (
 	github.com/tdewolff/canvas v0.0.0-20260923214215-09804640d00c
 	github.com/tdewolff/font v0.0.0-20260913163313-54f98bb59ee6
 	github.com/xiaoqidun/jbig2 v1.1.1
-	github.com/xiaoqidun/pdfgo v0.0.0-20260926152052-3a4cb2e9266a
+	github.com/xiaoqidun/pdfgo v0.0.0-20260927050705-f09ba3f6aa16
 	golang.org/x/crypto v0.57.0
 	golang.org/x/image v0.46.0
 	golang.org/x/text v0.42.0

go.sum

@@ -62,8 +62,8 @@ github.com/tdewolff/test v1.0.12 h1:7F21DqIajswxuche0geHdrUZRCWE4oko4b7bcmkkrxk=
 github.com/tdewolff/test v1.0.12/go.mod h1:XPuWBzvdUzhCuxWO1ojpXsyzsA5bFoS3tO/Q3kFuTG8=
 github.com/xiaoqidun/jbig2 v1.1.1 h1:SjliS9ZO0e9HX5oYUfBuXrfFsXhWricrSz+XY4zORDI=
 github.com/xiaoqidun/jbig2 v1.1.1/go.mod h1:8QonVWtENmh2kc6l+leqeGl7psb79DWlHDkCpdChjfQ=
-github.com/xiaoqidun/pdfgo v0.0.0-20260926152052-3a4cb2e9266a h1:BT4VQisXVY8OlUdZFE6WTOIktGk8fCQOfkWlSxvL+cc=
-github.com/xiaoqidun/pdfgo v0.0.0-20260926152052-3a4cb2e9266a/go.mod h1:4Pf0JO0BEf1uzRY+uZjlMjN/OPn3PYa0YMi6cqPPTLQ=
+github.com/xiaoqidun/pdfgo v0.0.0-20260927050705-f09ba3f6aa16 h1:yzUX5/pLl38Nczw+yQXck/QZ7sPblNvKu5+55cH6ONM=
+github.com/xiaoqidun/pdfgo v0.0.0-20260927050705-f09ba3f6aa16/go.mod h1:4Pf0JO0BEf1uzRY+uZjlMjN/OPn3PYa0YMi6cqPPTLQ=
 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/webui/wasm.go

@@ -921,7 +921,13 @@ func matchFontFiles(args []js.Value) (any, error) {
 	if currentSession == nil {
 		return nil, fmt.Errorf("ofd document is not opened")
 	}
-	return currentSession.Reader.MatchFontFiles(stringsFromJS(args[0]))
+	ids := make([]string, 0, len(currentSession.fontInfos))
+	for _, info := range currentSession.fontInfos {
+		if info.Used > 0 {
+			ids = append(ids, info.ID)
+		}
+	}
+	return currentSession.Reader.MatchFontFiles(stringsFromJS(args[0]), ids...)
 }
 
 // fontFaces 读取上传字体的名称和集合索引

ofdgo_font_fs.go

@@ -182,14 +182,19 @@ func FontFileMatches(files []string, bold, italic bool, names ...string) []strin
 	return fontFileMatchNames(fontFileMatches(fontFileCandidates(files, path.Base), names, bold, italic))
 }
 
-// MatchFontFiles 按文档字体名称和样式选择首选文件，跳过内嵌字体
-// 入参: files 可用字体文件名
+// MatchFontFiles 按文档字体名称和样式选择首选文件，未声明的使用编号按默认规则回退
+// 入参: files 可用字体文件名, ids 已发现的使用编号，省略时仅匹配声明字体
 // 返回: []string 所需字体文件名, error 错误信息
-func (r *Reader) MatchFontFiles(files []string) ([]string, error) {
+func (r *Reader) MatchFontFiles(files []string, ids ...string) ([]string, error) {
 	fonts, err := r.Fonts()
 	if err != nil {
 		return nil, err
 	}
+	for _, id := range ids {
+		if r.fontCache[id] == nil {
+			fonts = append(fonts, Font{ID: id})
+		}
+	}
 	candidates := fontFileCandidates(files, path.Base)
 	names := make([]string, 0, len(fonts))
 	seen := make(map[string]bool)

ofdgo_font_info.go

@@ -262,13 +262,13 @@ func (r *Renderer) fontInfos(usage map[string]int) ([]FontInfo, error) {
 		if seen[id] {
 			continue
 		}
-		infos = append(infos, FontInfo{
-			ID:       id,
-			FontName: id,
-			Status:   FontStatusMissing,
-			Detail:   "字体资源未被声明",
-			Used:     used,
-		})
+		info := r.fontInfo(Font{ID: id})
+		info.FontName, info.Used = id, used
+		info.Detail = "字体资源未被声明"
+		if info.Status == FontStatusFallback {
+			info.Detail += "，使用外部字体回退"
+		}
+		infos = append(infos, info)
 	}
 	sort.SliceStable(infos, func(i, j int) bool {
 		if infos[i].Used == 0 && infos[j].Used > 0 {

ofdgo_font_source.go

@@ -152,28 +152,29 @@ func (r *Renderer) resolveFontSource(backend FontBackend, id string, exact bool)
 		}
 		definition = r.Reader.fontCache[id]
 	}
-	if definition != nil {
-		if definition.FontFile != "" {
-			data, err := r.Reader.FontData(id)
-			if err != nil {
-				return ResolvedFont{}, err
-			}
-			face, err := r.Reader.embeddedFontFace(*definition)
-			if err != nil {
-				return ResolvedFont{}, err
-			}
-			return ResolvedFont{Data: data, Source: path.Base(definition.FontFile), Face: face, Exact: true}, nil
+	if definition == nil {
+		definition = &Font{ID: id}
+	}
+	if definition.FontFile != "" {
+		data, err := r.Reader.FontData(id)
+		if err != nil {
+			return ResolvedFont{}, err
 		}
-		if source, metrics := r.fontSourceMatch(backend, id, definition, exact); metrics != nil {
-			data := metrics.Write()
-			faces, err := (FontFile{Data: data}).Faces()
-			if err != nil {
-				return ResolvedFont{}, err
-			}
-			face := faces[0]
-			face.Index = source.face
-			return ResolvedFont{Data: data, Source: source.name, Face: &face, Exact: source.exact}, nil
+		face, err := r.Reader.embeddedFontFace(*definition)
+		if err != nil {
+			return ResolvedFont{}, err
 		}
+		return ResolvedFont{Data: data, Source: path.Base(definition.FontFile), Face: face, Exact: true}, nil
+	}
+	if source, metrics := r.fontSourceMatch(backend, id, definition, exact); metrics != nil {
+		data := metrics.Write()
+		faces, err := (FontFile{Data: data}).Faces()
+		if err != nil {
+			return ResolvedFont{}, err
+		}
+		face := faces[0]
+		face.Index = source.face
+		return ResolvedFont{Data: data, Source: source.name, Face: &face, Exact: source.exact}, nil
 	}
 	if exact {
 		return ResolvedFont{}, fmt.Errorf("font %q is unavailable", id)
@@ -238,6 +239,11 @@ func (r *Renderer) fontSources(fontID string, font *Font) []fontSource {
 		}
 	}
 	sortFontSources(sources[systemStart:])
+	for _, dir := range r.fontDirs {
+		for _, match := range r.matchFontFiles(dir, nil, bold, italic) {
+			sources = appendFontSource(sources, seen, fontSource{kind: fontSourceFile, name: match.name, face: match.face})
+		}
+	}
 	for index := range r.fontFS {
 		for _, match := range r.matchFontFS(index, nil, bold, italic) {
 			sources = appendFontSource(sources, seen, fontSource{kind: fontSourceFS, index: index, name: match.name, face: match.face})

ofdgo_pdf_object.go

@@ -21,7 +21,9 @@ import (
 	"image"
 	"image/color"
 	"image/png"
+	"maps"
 	"math"
+	"slices"
 	"strconv"
 	"unicode/utf16"
 	"unicode/utf8"
@@ -409,6 +411,7 @@ func (p *pdfImporter) text(mark pdfgo.TextMark) error {
 }
 
 // pdfFontProgram 为PDF子集字体补齐封装表，保留字形轮廓和编号
+// 复合字体的重复映射区段按PDF字符映射重建，不改变CID对应的字形
 // 入参: source PDF字体, type1 已解析的Type1程序，nil时按需解析
 // 返回: []byte 封装后的字体数据, uint16 缺失度量前的完整字形数, error 错误信息
 func pdfFontProgram(source *pdfgo.Font, type1 *type1Program) ([]byte, uint16, error) {
@@ -470,9 +473,9 @@ func pdfFontProgram(source *pdfgo.Font, type1 *type1Program) ([]byte, uint16, er
 		tables["hmtx"] = tables["hmtx"][:metricLength]
 		changed = true
 	}
-	if len(tables["cmap"]) == 0 {
+	if len(tables["cmap"]) == 0 || source.Subtype == "Type0" && pdfCmapOverlaps(tables["cmap"]) {
 		mapping := map[rune]uint16{}
-		for code := range source.Unicode {
+		for _, code := range slices.Sorted(maps.Keys(source.Unicode)) {
 			glyphs, err := source.Decode([]byte(code))
 			if err != nil {
 				return nil, 0, err
@@ -536,6 +539,42 @@ func pdfFontProgram(source *pdfgo.Font, type1 *type1Program) ([]byte, uint16, er
 	return result, repairedLimit, err
 }
 
+// pdfCmapOverlaps 检查格式4字符映射是否包含交叠区段
+// 入参: data cmap表数据
+// 返回: bool 是否存在交叠
+func pdfCmapOverlaps(data []byte) bool {
+	if len(data) < 4 {
+		return false
+	}
+	count := int(binary.BigEndian.Uint16(data[2:]))
+	if count > (len(data)-4)/8 {
+		return false
+	}
+	for index := range count {
+		offset := uint64(binary.BigEndian.Uint32(data[8+8*index:]))
+		if offset > uint64(len(data)) || uint64(len(data))-offset < 16 {
+			continue
+		}
+		sub := data[int(offset):]
+		if binary.BigEndian.Uint16(sub) != 4 {
+			continue
+		}
+		length := int(binary.BigEndian.Uint16(sub[2:]))
+		segments := int(binary.BigEndian.Uint16(sub[6:])) / 2
+		if length > len(sub) || 16+8*segments > length {
+			continue
+		}
+		for i := 1; i < segments; i++ {
+			previous := binary.BigEndian.Uint16(sub[14+2*(i-1):])
+			start := binary.BigEndian.Uint16(sub[16+2*segments+2*i:])
+			if start <= previous {
+				return true
+			}
+		}
+	}
+	return false
+}
+
 // pdfSFNTMissingPadding 判断字体表目录是否引用了未写入的末尾对齐字节
 // 入参: program OpenType字体数据
 // 返回: bool 是否需要重新封装

ofdgo_renderer_font_loader_canvas.go

@@ -44,7 +44,7 @@ func (r *Renderer) loadFont(fontID string) *canvas.FontFamily {
 		return nil
 	}
 	if of == nil {
-		of = &Font{ID: fontID, FontName: "default"}
+		of = &Font{ID: fontID, FontName: "OFDGoFallback"}
 	}
 	fontData := resolved.Data
 	fontStyle := canvasFontStyle(of)