feat(字体渲染): 优化字体渲染

ofdgo_font_match.go

@@ -24,9 +24,17 @@ type fontMatchRule struct {
 	Names           []string
 	Files           []string
 	System          string
+	NoSyntheticBold bool
 }
 
 var fontMatchRules = []fontMatchRule{
+	{
+		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", "xiaobiaosong*.ttf"},
+		System:          "FZXiaoBiaoSong-B05S",
+		NoSyntheticBold: true,
+	},
 	{
 		Keys:   []string{"宋体", "新宋体", "simsun", "nsimsun", "songti", "书宋", "方正书宋"},
 		Names:  []string{"宋体", "新宋体", "SimSun", "NSimSun", "SongTi"},
@@ -169,6 +177,20 @@ func fontDefaultSystemNames() []string {
 	}
 }
 
+// fontNoSyntheticBold 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 fontNoSyntheticBold(names ...string) bool {
+	for _, name := range names {
+		for _, rule := range fontMatchRules {
+			if rule.NoSyntheticBold && fontRuleMatch(rule, name) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
 // fontRuleMatch 判断字体规则是否匹配
 // 入参: rule 字体匹配规则, name 字体名称
 // 返回: bool 是否匹配

ofdgo_renderer.go

@@ -835,9 +835,7 @@ func (r *Renderer) renderText(ctx *canvas.Context, obj TextObject, pageH float64
 	if weight == 0 && dp != nil && dp.Weight > 0 {
 		weight = dp.Weight
 	}
-	if weight >= 700 {
+	syntheticBold := weight >= 700
-		fontStyle |= canvas.FontBold
-	}
 	italic := obj.Italic
 	if !italic && dp != nil && dp.Italic {
 		italic = true
@@ -849,6 +847,9 @@ func (r *Renderer) renderText(ctx *canvas.Context, obj TextObject, pageH float64
 	embeddedFont := false
 	if of, ok := r.Reader.fontCache[fontID]; ok {
 		embeddedFont = of.FontFile != ""
+		if !embeddedFont && fontNoSyntheticBold(of.FontName, of.FamilyName) {
+			syntheticBold = false
+		}
 		if of.Bold {
 			fontStyle |= canvas.FontBold
 		}
@@ -856,6 +857,9 @@ func (r *Renderer) renderText(ctx *canvas.Context, obj TextObject, pageH float64
 			fontStyle |= canvas.FontItalic
 		}
 	}
+	if syntheticBold {
+		fontStyle |= canvas.FontBold
+	}
 	ff := r.loadFont(fontID)
 	if ff == nil {
 		return