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