crunchy-rocks/draw2d
2
0
Fork 0
Code Issues Pull requests Releases Wiki Activity

Implemented a proper GlyphCache interface

Browse source
This commit is contained in:
redstarcoder 2016-12-17 15:44:51 -05:00
parent 1286d3b203
commit df6b7d6902
1 changed files with 47 additions and 13 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

60
draw2dbase/text.go
View file

@ -2,25 +2,48 @@ package draw2dbase
import "github.com/llgcode/draw2d"
var glyphCache map[string]map[rune]*Glyph
var (
glyphCacheDefault = &defaultGlyphCache{make(map[string]map[rune]*Glyph)}
glyphCache GlyphCache = glyphCacheDefault
)
func init() {
glyphCache = make(map[string]map[rune]*Glyph)
// Types implementing this interface can be passed to SetGlyphCache to change the
// 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
func FetchGlyph(gc draw2d.GraphicContext, fontName string, chr rune) *Glyph {
if glyphCache[fontName] == nil {
glyphCache[fontName] = make(map[rune]*Glyph, 60)
// Changes the glyph cache backend used by the package.
// To restore the default glyph cache, call this function passing nil as argument.
func SetGlyphCache(cache GlyphCache) {
if cache == nil {
glyphCache = glyphCacheDefault
} else {
glyphCache = cache
}
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
func renderGlyph(gc draw2d.GraphicContext, fontName string, chr rune) *Glyph {
type defaultGlyphCache struct {
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()
@ -32,6 +55,16 @@ func renderGlyph(gc draw2d.GraphicContext, fontName string, chr rune) *Glyph {
}
}
// 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 {
return glyphCache.Fetch(gc, fontName, chr)
}
// renderGlyph renders a glyph then caches and returns it
func renderGlyph(gc draw2d.GraphicContext, fontName string, chr rune) *Glyph {
return glyphCache.Render(gc, fontName, chr)
}
// 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)
@ -40,6 +73,7 @@ type Glyph struct {
Width float64
}
// Copy copys the Glyph, and returns the copy
func (g *Glyph) Copy() *Glyph {
return &Glyph{
path: g.path.Copy(),