feat(优化性能): 继续提升性能

ofdgo.go

@@ -72,6 +72,7 @@ func NewRenderer(reader *Reader, opts ...RendererOption) *Renderer {
 		CompositeGraphicUnits: reader.compositeGraphicUnitCache,
 		FontMap:               make(map[string]*canvas.FontFamily),
 		fontFSCache:           make(map[fontFSKey]*canvas.FontFamily),
+		textGlyphPathCache:    make(map[textGlyphPathCacheKey]textGlyphPathCacheValue),
 	}
 	for _, opt := range opts {
 		opt(r)

ofdgo_renderer.go

@@ -34,6 +34,7 @@ type Renderer struct {
 	FontGIDMap            map[string]map[uint16]rune
 	FontCIDMap            map[string]map[uint16]rune
 	fontFSCache           map[fontFSKey]*canvas.FontFamily
+	textGlyphPathCache    map[textGlyphPathCacheKey]textGlyphPathCacheValue
 	fontDirs              []string
 	fontFS                []fs.FS
 }

ofdgo_renderer_text.go

@@ -148,7 +148,7 @@ func (r *Renderer) renderText(ctx *canvas.Context, obj TextObject, pageH float64
 			var glyphPath *canvas.Path
 			var glyphWidth float64
 			if drawAsGlyphPath {
-				glyphPath, glyphWidth = textGlyphPath(face, glyph)
+				glyphPath, glyphWidth = r.cachedTextGlyphPath(face, glyph)
 			} else {
 				glyphWidth = textGlyphWidth(face, glyph)
 			}

ofdgo_text.go

@@ -20,6 +20,7 @@ import (
 	"strings"
 
 	"github.com/tdewolff/canvas"
+	canvastext "github.com/tdewolff/canvas/text"
 	"github.com/tdewolff/font"
 )
 
@@ -29,6 +30,26 @@ type textGlyph struct {
 	GlyphID int
 }
 
+// textGlyphPathCacheKey 字形路径缓存键
+type textGlyphPathCacheKey struct {
+	font       *canvas.Font
+	size       float64
+	fauxBold   float64
+	fauxItalic float64
+	xOffset    int32
+	yOffset    int32
+	language   string
+	script     canvastext.Script
+	direction  canvastext.Direction
+	glyph      textGlyph
+}
+
+// textGlyphPathCacheValue 字形路径缓存值
+type textGlyphPathCacheValue struct {
+	path  *canvas.Path
+	width float64
+}
+
 // textGlyphTransform 字符到字形变换
 type textGlyphTransform struct {
 	CodeCount int
@@ -161,6 +182,30 @@ func textGlyphPath(face *canvas.FontFace, glyph textGlyph) (*canvas.Path, float6
 	return p, face.MmPerEm * float64(face.Font.GlyphAdvance(glyphID))
 }
 
+// cachedTextGlyphPath 获取缓存的字形路径
+// 入参: face 字体, glyph 绘制字形
+// 返回: *canvas.Path 字形路径, float64 字形宽度
+func (r *Renderer) cachedTextGlyphPath(face *canvas.FontFace, glyph textGlyph) (*canvas.Path, float64) {
+	key := textGlyphPathCacheKey{
+		font:       face.Font,
+		size:       face.Size,
+		fauxBold:   face.FauxBold,
+		fauxItalic: face.FauxItalic,
+		xOffset:    face.XOffset,
+		yOffset:    face.YOffset,
+		language:   face.Language,
+		script:     face.Script,
+		direction:  face.Direction,
+		glyph:      glyph,
+	}
+	if cached, ok := r.textGlyphPathCache[key]; ok {
+		return cached.path, cached.width
+	}
+	path, width := textGlyphPath(face, glyph)
+	r.textGlyphPathCache[key] = textGlyphPathCacheValue{path: path, width: width}
+	return path, width
+}
+
 // hasTextMatrix 判断文本是否需要应用字形变换
 // 入参: ctm 变换矩阵
 // 返回: bool 是否需要变换