Merge c01ed99433 into 4cdcb11e52

draw2dbase/text.go

@@ -2,67 +2,85 @@ package draw2dbase
 
 import "github.com/llgcode/draw2d"
 
-var glyphCache map[string]map[rune]*Glyph
+var (
+	DefaultGlyphCache = &defaultGlyphCache{make(map[string]map[rune]*Glyph)}
+)
 
-func init() {
+// Types implementing this interface can be passed to gc.SetGlyphCache to change the
-	glyphCache = make(map[string]map[rune]*Glyph)
+// way glyphs are being stored and retrieved.
+type GlyphCache interface {
+	// Fetch fetches a glyph from the cache, storing with Render first if it doesn't already exist
+	Fetch(gc draw2d.GraphicContext, fontName string, chr rune) *Glyph
+
+	// Render renders a glyph then returns it
+	Render(gc draw2d.GraphicContext, fontName string, chr rune) *Glyph
 }
 
-// FetchGlyph fetches a glyph from the cache, calling renderGlyph first if it doesn't already exist
+// NewGlyphCache creates and returns a new GlyphCache
-func FetchGlyph(gc draw2d.GraphicContext, fontName string, chr rune) *Glyph {
+func NewGlyphCache() GlyphCache {
-	if glyphCache[fontName] == nil {
+	return &defaultGlyphCache{make(map[string]map[rune]*Glyph)}
-		glyphCache[fontName] = make(map[rune]*Glyph, 60)
-	}
-	if glyphCache[fontName][chr] == nil {
-		glyphCache[fontName][chr] = renderGlyph(gc, fontName, chr)
-	}
-	return glyphCache[fontName][chr].Copy()
 }
 
-// renderGlyph renders a glyph then caches and returns it
+type defaultGlyphCache struct {
-func renderGlyph(gc draw2d.GraphicContext, fontName string, chr rune) *Glyph {
+	glyphMap map[string]map[rune]*Glyph
+}
+
+// Fetch fetches a glyph from the cache, storing with Render first if it doesn't already exist
+func (cache *defaultGlyphCache) Fetch(gc draw2d.GraphicContext, fontName string, chr rune) *Glyph {
+	if cache.glyphMap[fontName] == nil {
+		cache.glyphMap[fontName] = make(map[rune]*Glyph, 60)
+	}
+	if cache.glyphMap[fontName][chr] == nil {
+		cache.glyphMap[fontName][chr] = cache.Render(gc, fontName, chr)
+	}
+	return cache.glyphMap[fontName][chr].Copy()
+}
+
+// Render renders a glyph then returns it
+func (cache *defaultGlyphCache) Render(gc draw2d.GraphicContext, fontName string, chr rune) *Glyph {
 	gc.Save()
 	defer gc.Restore()
 	gc.BeginPath()
 	width := gc.CreateStringPath(string(chr), 0, 0)
 	path := gc.GetPath()
 	return &Glyph{
-		path:  &path,
+		Path:  &path,
 		Width: width,
 	}
 }
 
 // Glyph represents a rune which has been converted to a Path and width
 type Glyph struct {
-	// path represents a glyph, it is always at (0, 0)
+	// Path represents a glyph, it is always at (0, 0)
-	path *draw2d.Path
+	Path *draw2d.Path
 	// Width of the glyph
 	Width float64
 }
 
+// Copy copys the Glyph, and returns the copy
 func (g *Glyph) Copy() *Glyph {
 	return &Glyph{
-		path:  g.path.Copy(),
+		Path:  g.Path.Copy(),
 		Width: g.Width,
 	}
 }
 
-// Fill copies a glyph from the cache, and fills it
+// Fill fills a Glyph in the specified coordinates
 func (g *Glyph) Fill(gc draw2d.GraphicContext, x, y float64) float64 {
 	gc.Save()
 	gc.BeginPath()
 	gc.Translate(x, y)
-	gc.Fill(g.path)
+	gc.Fill(g.Path)
 	gc.Restore()
 	return g.Width
 }
 
-// Stroke fetches a glyph from the cache, and strokes it
+// Stroke strokes a Glyph in the specified coordinates
 func (g *Glyph) Stroke(gc draw2d.GraphicContext, x, y float64) float64 {
 	gc.Save()
 	gc.BeginPath()
 	gc.Translate(x, y)
-	gc.Stroke(g.path)
+	gc.Stroke(g.Path)
 	gc.Restore()
 	return g.Width
 }

draw2dgl/gc.go

@@ -126,7 +126,8 @@ type GraphicContext struct {
 	fillRasterizer   *raster.Rasterizer
 	strokeRasterizer *raster.Rasterizer
 	glyphBuf         *truetype.GlyphBuf
-	DPI		int
+	glyphCache       draw2dbase.GlyphCache
+	DPI              int
 }
 
 // NewGraphicContext creates a new Graphic context from an image.
@@ -137,6 +138,7 @@ func NewGraphicContext(width, height int) *GraphicContext {
 		raster.NewRasterizer(width, height),
 		raster.NewRasterizer(width, height),
 		&truetype.GlyphBuf{},
+		draw2dbase.DefaultGlyphCache,
 		92,
 	}
 	return gc
@@ -217,7 +219,7 @@ func (gc *GraphicContext) FillStringAt(text string, x, y float64) (width float64
 		if hasPrev {
 			x += fUnitsToFloat64(f.Kern(fixed.Int26_6(gc.Current.Scale), prev, index))
 		}
-		glyph := draw2dbase.FetchGlyph(gc, fontName, r)
+		glyph := gc.glyphCache.Fetch(gc, fontName, r)
 		x += glyph.Fill(gc, x, y)
 		prev, hasPrev = index, true
 	}
@@ -283,7 +285,7 @@ func (gc *GraphicContext) StrokeStringAt(text string, x, y float64) (width float
 		if hasPrev {
 			x += fUnitsToFloat64(f.Kern(fixed.Int26_6(gc.Current.Scale), prev, index))
 		}
-		glyph := draw2dbase.FetchGlyph(gc, fontName, r)
+		glyph := gc.glyphCache.Fetch(gc, fontName, r)
 		x += glyph.Stroke(gc, x, y)
 		prev, hasPrev = index, true
 	}
@@ -312,6 +314,16 @@ func (gc *GraphicContext) SetFontSize(fontSize float64) {
 	gc.recalc()
 }
 
+// Changes the glyph cache backend used by the GraphicContext.
+// To restore the default glyph cache, call this function passing nil as argument.
+func (gc *GraphicContext) SetGlyphCache(cache draw2dbase.GlyphCache) {
+	if cache == nil {
+		gc.glyphCache = draw2dbase.DefaultGlyphCache
+	} else {
+		gc.glyphCache = cache
+	}
+}
+
 func (gc *GraphicContext) GetDPI() int {
 	return gc.DPI
 }

draw2dimg/ftgc.go

@@ -36,6 +36,7 @@ type GraphicContext struct {
 	fillRasterizer   *raster.Rasterizer
 	strokeRasterizer *raster.Rasterizer
 	glyphBuf         *truetype.GlyphBuf
+	glyphCache       draw2dbase.GlyphCache
 	DPI              int
 }
 
@@ -75,6 +76,7 @@ func NewGraphicContextWithPainter(img draw.Image, painter Painter) *GraphicConte
 		raster.NewRasterizer(width, height),
 		raster.NewRasterizer(width, height),
 		&truetype.GlyphBuf{},
+		draw2dbase.DefaultGlyphCache,
 		dpi,
 	}
 	return gc
@@ -136,7 +138,7 @@ func (gc *GraphicContext) FillStringAt(text string, x, y float64) (width float64
 		if hasPrev {
 			x += fUnitsToFloat64(f.Kern(fixed.Int26_6(gc.Current.Scale), prev, index))
 		}
-		glyph := draw2dbase.FetchGlyph(gc, fontName, r)
+		glyph := gc.glyphCache.Fetch(gc, fontName, r)
 		x += glyph.Fill(gc, x, y)
 		prev, hasPrev = index, true
 	}
@@ -163,7 +165,7 @@ func (gc *GraphicContext) StrokeStringAt(text string, x, y float64) (width float
 		if hasPrev {
 			x += fUnitsToFloat64(f.Kern(fixed.Int26_6(gc.Current.Scale), prev, index))
 		}
-		glyph := draw2dbase.FetchGlyph(gc, fontName, r)
+		glyph := gc.glyphCache.Fetch(gc, fontName, r)
 		x += glyph.Stroke(gc, x, y)
 		prev, hasPrev = index, true
 	}
@@ -291,6 +293,16 @@ func (gc *GraphicContext) SetFontSize(fontSize float64) {
 	gc.recalc()
 }
 
+// Changes the glyph cache backend used by the GraphicContext.
+// To restore the default glyph cache, call this function passing nil as argument.
+func (gc *GraphicContext) SetGlyphCache(cache draw2dbase.GlyphCache) {
+	if cache == nil {
+		gc.glyphCache = draw2dbase.DefaultGlyphCache
+	} else {
+		gc.glyphCache = cache
+	}
+}
+
 func (gc *GraphicContext) paint(rasterizer *raster.Rasterizer, color color.Color) {
 	gc.painter.SetColor(color)
 	rasterizer.Rasterize(gc.painter)