}

func BenchmarkGlyphOver(b *testing.B) {
	bench(b, color.RGBAModel, nil, color.AlphaModel, Over)
}

func BenchmarkRGBAMaskOver(b *testing.B) {
	bench(b, color.RGBAModel, color.RGBAModel, color.AlphaModel, Over)
}

func BenchmarkGrayMaskOver(b *testing.B) {
	bench(b, color.RGBAModel, color.GrayModel, color.AlphaModel, Over)
}

func BenchmarkRGBA64ImageMaskOver(b *testing.B) {

var (
	RGBAModel    Model = ModelFunc(rgbaModel)
	RGBA64Model  Model = ModelFunc(rgba64Model)
	NRGBAModel   Model = ModelFunc(nrgbaModel)
	NRGBA64Model Model = ModelFunc(nrgba64Model)
	AlphaModel   Model = ModelFunc(alphaModel)
	Alpha16Model Model = ModelFunc(alpha16Model)
	GrayModel    Model = ModelFunc(grayModel)
	Gray16Model  Model = ModelFunc(gray16Model)
)

func rgbaModel(c Color) Color {