// Draw implements the Drawer interface from the standard library's image/draw
// package.
//
// The vector paths previously added via the XxxTo calls become the mask for
// drawing src onto dst.
func (z *Rasterizer) Draw(dst draw.Image, r image.Rectangle, src image.Image, sp image.Point) {
// TODO: adjust r and sp (and mp?) if src.Bounds() doesn't contain
// r.Add(sp.Sub(r.Min)).
if src, ok := src.(*image.Uniform); ok {
srcR, srcG, srcB, srcA := src.RGBA()
switch dst := dst.(type) {
case *image.Alpha:
// Fast path for glyph rendering.
if srcA == 0xffff {
if z.DrawOp == draw.Over {
z.rasterizeDstAlphaSrcOpaqueOpOver(dst, r)
} else {
z.rasterizeDstAlphaSrcOpaqueOpSrc(dst, r)
}
return
}
case *image.RGBA:
if z.DrawOp == draw.Over {
z.rasterizeDstRGBASrcUniformOpOver(dst, r, srcR, srcG, srcB, srcA)
} else {
z.rasterizeDstRGBASrcUniformOpSrc(dst, r, srcR, srcG, srcB, srcA)
}
return
}
}
if z.DrawOp == draw.Over {
z.rasterizeOpOver(dst, r, src, sp)
} else {
z.rasterizeOpSrc(dst, r, src, sp)
}
}
// Draw implements the Drawer interface from the standard library's image/draw
// package.
//
// The vector paths previously added via the XxxTo calls become the mask for
// drawing src onto dst.
func (z *Rasterizer) Draw(dst draw.Image, r image.Rectangle, src image.Image, sp image.Point) {
if src, ok := src.(*image.Uniform); ok {
_, _, _, srcA := src.RGBA()
switch dst := dst.(type) {
case *image.Alpha:
// Fast path for glyph rendering.
if srcA == 0xffff && z.DrawOp == draw.Src {
z.rasterizeDstAlphaSrcOpaqueOpSrc(dst, r)
return
}
}
}
println("TODO: the general case")
}
// NewPainter returns a Painter that will draw from src onto
// dst using the Porter-Duff composition operator op.
func NewPainter(dst draw.Image, src image.Image, op draw.Op) (p raster.Painter) {
defer func() { fmt.Printf("newpainter %T\n", p) }()
if src, ok := src.(*image.Uniform); ok {
switch dst := dst.(type) {
case *image.Alpha:
if _, _, _, a := src.RGBA(); a == 0xffff {
switch op {
case draw.Src:
return &raster.AlphaSrcPainter{dst}
case draw.Over:
return &raster.AlphaOverPainter{dst}
}
}
case *image.RGBA:
p := raster.NewRGBAPainter(dst)
p.SetColor(src)
p.Op = op
return p
}
}
return &genericImagePainter{dst, src, op}
}