fix #131

draw2dbase/text.go

@@ -2,21 +2,29 @@ package draw2dbase
 
 import "github.com/llgcode/draw2d"
 
-var glyphCache map[string]map[rune]*Glyph
+// GlyphCache manage a map of glyphs
+type GlyphCache struct {
+	glyphs map[string]map[rune]*Glyph
+}
 
-func init() {
-	glyphCache = make(map[string]map[rune]*Glyph)
+
+// NewGlyphCache initializes a GlyphCache
+func NewGlyphCache() *GlyphCache {
+	glyphs := make(map[string]map[rune]*Glyph)
+	return &GlyphCache {
+		glyphs: glyphs,
+	}
 }
 
 // FetchGlyph fetches a glyph from the cache, calling renderGlyph first if it doesn't already exist
-func FetchGlyph(gc draw2d.GraphicContext, fontName string, chr rune) *Glyph {
-	if glyphCache[fontName] == nil {
-		glyphCache[fontName] = make(map[rune]*Glyph, 60)
+func (glyphCache *GlyphCache) FetchGlyph(gc draw2d.GraphicContext, fontName string, chr rune) *Glyph {
+	if glyphCache.glyphs[fontName] == nil {
+		glyphCache.glyphs[fontName] = make(map[rune]*Glyph, 60)
 	}
-	if glyphCache[fontName][chr] == nil {
-		glyphCache[fontName][chr] = renderGlyph(gc, fontName, chr)
+	if glyphCache.glyphs[fontName][chr] == nil {
+		glyphCache.glyphs[fontName][chr] = renderGlyph(gc, fontName, chr)
 	}
-	return glyphCache[fontName][chr].Copy()
+	return glyphCache.glyphs[fontName][chr].Copy()
 }
 
 // renderGlyph renders a glyph then caches and returns it
@@ -40,6 +48,7 @@ type Glyph struct {
 	Width float64
 }
 
+// Returns a copy of a Glyph
 func (g *Glyph) Copy() *Glyph {
 	return &Glyph{
 		path:  g.path.Copy(),

draw2dimg/ftgc.go

@@ -4,7 +4,6 @@
 package draw2dimg
 
 import (
-	"errors"
 	"image"
 	"image/color"
 	"log"
@@ -35,6 +34,8 @@ type GraphicContext struct {
 	painter          Painter
 	fillRasterizer   *raster.Rasterizer
 	strokeRasterizer *raster.Rasterizer
+	FontCache		 draw2d.FontCache
+	glyphCache       *draw2dbase.GlyphCache
 	glyphBuf         *truetype.GlyphBuf
 	DPI              int
 }
@@ -74,6 +75,8 @@ func NewGraphicContextWithPainter(img draw.Image, painter Painter) *GraphicConte
 		painter,
 		raster.NewRasterizer(width, height),
 		raster.NewRasterizer(width, height),
+		draw2d.GetGlobalFontCache(),
+		draw2dbase.NewGlyphCache(),
 		&truetype.GlyphBuf{},
 		dpi,
 	}
@@ -136,7 +139,7 @@ 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.FetchGlyph(gc, fontName, r)
 		x += glyph.Fill(gc, x, y)
 		prev, hasPrev = index, true
 	}
@@ -163,7 +166,7 @@ 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.FetchGlyph(gc, fontName, r)
 		x += glyph.Stroke(gc, x, y)
 		prev, hasPrev = index, true
 	}
@@ -171,16 +174,15 @@ func (gc *GraphicContext) StrokeStringAt(text string, x, y float64) (width float
 }
 
 func (gc *GraphicContext) loadCurrentFont() (*truetype.Font, error) {
-	font := draw2d.GetFont(gc.Current.FontData)
-	if font == nil {
-		font = draw2d.GetFont(draw2dbase.DefaultFontData)
+	font, err := gc.FontCache.Load(gc.Current.FontData)
+	if err != nil {
+		font, err = gc.FontCache.Load(draw2dbase.DefaultFontData)
 	}
-	if font == nil {
-		return nil, errors.New("No font set, and no default font available.")
+	if font != nil {
+		gc.SetFont(font)
+		gc.SetFontSize(gc.Current.FontSize)
 	}
-	gc.SetFont(font)
-	gc.SetFontSize(gc.Current.FontSize)
-	return font, nil
+	return font, err
 }
 
 // p is a truetype.Point measured in FUnits and positive Y going upwards.

font.go

@@ -79,6 +79,10 @@ func GetFontFolder() string {
 	return defaultFonts.folder
 }
 
+func GetGlobalFontCache() FontCache {
+	return defaultFonts
+}
+
 func SetFontFolder(folder string) {
 	defaultFonts.folder = filepath.Clean(folder)
 }
@@ -113,13 +117,24 @@ func SetFontCache(cache FontCache) {
 	}
 }
 
-type defaultFontCache struct {
+// FolderFontCache can Load font from folder
+type FolderFontCache struct {
 	fonts  map[string]*truetype.Font
 	folder string
 	namer  FontFileNamer
 }
 
-func (cache *defaultFontCache) Load(fontData FontData) (font *truetype.Font, err error) {
+// NewFolderFontCache creates FolderFontCache 
+func NewFolderFontCache(folder string) *FolderFontCache {
+	return &FolderFontCache{
+		fonts:  make(map[string]*truetype.Font),
+		folder: folder,
+		namer:  FontFileName,
+	}
+}
+
+// Load a font from cache if exists otherwise it will load the font from file
+func (cache *FolderFontCache) Load(fontData FontData) (font *truetype.Font, err error) {
 	if font = cache.fonts[cache.namer(fontData)]; font != nil {
 		return font, nil
 	}
@@ -139,16 +154,13 @@ func (cache *defaultFontCache) Load(fontData FontData) (font *truetype.Font, err
 	return
 }
 
-func (cache *defaultFontCache) Store(fontData FontData, font *truetype.Font) {
+// Store a font to this cache
+func (cache *FolderFontCache) Store(fontData FontData, font *truetype.Font) {
 	cache.fonts[cache.namer(fontData)] = font
 }
 
 var (
-	defaultFonts = &defaultFontCache{
-		fonts:  make(map[string]*truetype.Font),
-		folder: "../resource/font",
-		namer:  FontFileName,
-	}
+	defaultFonts = NewFolderFontCache("../resource/font")
 
 	fontCache FontCache = defaultFonts
 )

sync_test.go

@@ -2,6 +2,7 @@
 
 package draw2d_test
 
+
 import (
 	"fmt"
 	"github.com/llgcode/draw2d"
@@ -25,10 +26,10 @@ func TestSync(t *testing.T) {
 }
 
 func Draw(i int, ch chan<- int) {
-	draw2d.SetFontFolder("./resource/font")
 	// Draw a rounded rectangle using default colors
 	dest := image.NewRGBA(image.Rect(0, 0, 297, 210.0))
 	gc := draw2dimg.NewGraphicContext(dest)
+	gc.FontCache = draw2d.NewFolderFontCache("./resource/font")
 
 	draw2dkit.RoundedRectangle(gc, 5, 5, 135, 95, 10, 10)
 	gc.FillStroke()