refactor(文件拆分): 考虑到可维护性进行了文件拆分

ofdgo_font_loader.go

@@ -0,0 +1,191 @@
+// 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 ofdgo
+
+import (
+	"io/fs"
+	"path/filepath"
+	"runtime"
+
+	"github.com/tdewolff/canvas"
+)
+
+// loadFont 加载字体
+// 入参: fontID 字体ID
+// 返回: *canvas.FontFamily 字体族
+func (r *Renderer) loadFont(fontID string) *canvas.FontFamily {
+	if ff, ok := r.FontMap[fontID]; ok {
+		return ff
+	}
+	var defaultFont *canvas.FontFamily
+	if r.defaultFontLoaded {
+		defaultFont = r.fontFamily
+	}
+	of, ok := r.Reader.fontCache[fontID]
+	if !ok {
+		return defaultFont
+	}
+	ff := canvas.NewFontFamily(of.FontName)
+	if of.FontFile != "" {
+		if fontData, err := r.Reader.ResData(of.FontFile); err == nil {
+			if cidMap := getCFFCIDRuneMap(fontData); len(cidMap) > 0 {
+				if r.FontCIDMap == nil {
+					r.FontCIDMap = make(map[string]map[uint16]rune)
+				}
+				r.FontCIDMap[fontID] = cidMap
+			}
+			if _, fixedData, mapping, _, err := FixFontDataAggressive(fontData, true, true); err == nil {
+				fontData = fixedData
+				if mapping != nil {
+					if r.FontGIDMap == nil {
+						r.FontGIDMap = make(map[string]map[uint16]rune)
+					}
+					inv := make(map[uint16]rune)
+					for k, v := range mapping {
+						if k == packedGlyphRune(v) {
+							inv[v] = k
+						}
+					}
+					for k, v := range mapping {
+						if _, ok := inv[v]; !ok {
+							inv[v] = k
+						}
+					}
+					r.FontGIDMap[fontID] = inv
+				}
+			}
+			var fontStyle canvas.FontStyle
+			if of.Bold {
+				fontStyle |= canvas.FontBold
+			}
+			if of.Italic {
+				fontStyle |= canvas.FontItalic
+			}
+			if err := ff.LoadFont(fontData, 0, fontStyle); err == nil {
+				r.FontMap[fontID] = ff
+				return ff
+			}
+			return nil
+		}
+		return nil
+	}
+	var fontStyle canvas.FontStyle
+	if of.Bold {
+		fontStyle |= canvas.FontBold
+	}
+	if of.Italic {
+		fontStyle |= canvas.FontItalic
+	}
+	boldStyle := fontStyle&canvas.FontBold != 0
+	italicStyle := fontStyle&canvas.FontItalic != 0
+	patterns := fontFilePatterns(of.FontName, of.FamilyName)
+	for _, dir := range r.fontDirs {
+		for _, m := range r.matchFontFiles(dir, patterns, boldStyle, italicStyle) {
+			if err := ff.LoadFontFile(m, fontStyle); err == nil {
+				r.FontMap[fontID] = ff
+				return ff
+			}
+		}
+	}
+	for _, fsys := range r.fontFS {
+		for _, m := range fontFSMatchesStyle(fsys, patterns, boldStyle, italicStyle) {
+			resData, err := fs.ReadFile(fsys, m)
+			if err == nil {
+				if err := ff.LoadFont(resData, 0, fontStyle); err == nil {
+					r.FontMap[fontID] = ff
+					return ff
+				}
+			}
+		}
+	}
+	if !canLoadSystemFonts() {
+		for _, fsys := range r.fontFS {
+			if matches, err := fs.Glob(fsys, "*"); err == nil {
+				for _, m := range matches {
+					resData, err := fs.ReadFile(fsys, m)
+					if err == nil {
+						if err := ff.LoadFont(resData, 0, fontStyle); err == nil {
+							r.FontMap[fontID] = ff
+							return ff
+						}
+					}
+				}
+			}
+		}
+		r.FontMap[fontID] = defaultFont
+		return defaultFont
+	}
+	names := []string{of.FamilyName, of.FontName}
+	for _, name := range names {
+		if name == "" {
+			continue
+		}
+		for _, targetName := range fontSystemNames(name) {
+			for _, m := range r.matchFontFiles(systemFontDir(), fontFilePatterns(targetName), boldStyle, italicStyle) {
+				if err := ff.LoadFontFile(m, fontStyle); err == nil {
+					r.FontMap[fontID] = ff
+					return ff
+				}
+			}
+			if err := ff.LoadSystemFont(targetName, fontStyle); err == nil {
+				r.FontMap[fontID] = ff
+				return ff
+			}
+		}
+		for _, m := range r.matchFontFiles(systemFontDir(), fontFilePatterns(name), boldStyle, italicStyle) {
+			if err := ff.LoadFontFile(m, fontStyle); err == nil {
+				r.FontMap[fontID] = ff
+				return ff
+			}
+		}
+	}
+	r.FontMap[fontID] = defaultFont
+	return defaultFont
+}
+
+// matchFontFiles 查找字体文件
+// 入参: dir 目录, patterns 模式列表, bold 是否粗体, italic 是否斜体
+// 返回: []string 文件列表
+func (r *Renderer) matchFontFiles(dir string, patterns []string, bold, italic bool) []string {
+	var matches []fontFileMatch
+	index := make(map[string]int)
+	add := func(pattern, name string, rank int) {
+		if !isFontFileName(name) {
+			return
+		}
+		appendFontFileMatch(&matches, index, pattern, name, rank, bold, italic)
+	}
+	files, _ := filepath.Glob(filepath.Join(dir, "*"))
+	for _, pattern := range patterns {
+		for _, name := range files {
+			add(pattern, name, matchFontPatternRank(pattern, filepath.Base(name)))
+		}
+	}
+	sortFontFileMatches(matches, bold, italic)
+	return fontFileMatchNames(matches)
+}
+
+// systemFontDir 获取系统字体目录
+// 返回: string 字体目录
+func systemFontDir() string {
+	switch runtime.GOOS {
+	case "linux":
+		return `/usr/share/fonts`
+	case "darwin":
+		return `/Library/Fonts`
+	default:
+		return `C:\Windows\Fonts`
+	}
+}