71 lines
1.8 KiB
Go
71 lines
1.8 KiB
Go
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package draw2dbase
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import "github.com/llgcode/draw2d"
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var glyphCache map[string]map[rune]*glyph
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func init() {
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glyphCache = make(map[string]map[rune]*glyph)
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}
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// FillGlyph copies a glyph from the cache, copies it to the gc, and fills it
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func FillGlyph(gc draw2d.GraphicContext, x, y float64, fontName string, chr rune) float64 {
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g := fetchGlyph(gc, fontName, chr)
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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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// StrokeGlyph fetches a glyph from the cache, copies it to the gc, and strokes it
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func StrokeGlyph(gc draw2d.GraphicContext, x, y float64, fontName string, chr rune) float64 {
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g := fetchGlyph(gc, fontName, chr)
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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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// fetchGlyph fetches a glyph from the cache, calling renderGlyph first if it doesn't already exist
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func fetchGlyph(gc draw2d.GraphicContext, fontName string, chr rune) *glyph {
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if glyphCache[fontName] == nil {
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glyphCache[fontName] = make(map[rune]*glyph, 60)
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}
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if glyphCache[fontName][chr] == nil {
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glyphCache[fontName][chr] = renderGlyph(gc, fontName, chr)
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}
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return glyphCache[fontName][chr].Copy()
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}
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// renderGlyph renders a Glyph then caches and returns it
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func renderGlyph(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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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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