canvas/backend/software/fill.go
2019-05-12 13:06:23 +02:00

80 lines
1.6 KiB
Go

package softwarebackend
import (
"image"
"image/color"
"github.com/tfriedel6/canvas/backend/backendbase"
)
func (b *SoftwareBackend) Clear(pts [4][2]float64) {
iterateTriangles(pts[:], func(tri [][2]float64) {
b.fillTriangle(tri, func(x, y int) {
if b.clip.AlphaAt(x, y).A == 0 {
return
}
b.Image.SetRGBA(x, y, color.RGBA{})
})
})
}
func (b *SoftwareBackend) Fill(style *backendbase.FillStyle, pts [][2]float64) {
p2 := b.mask.Pix
for i := range p2 {
p2[i] = 0
}
iterateTriangles(pts[:], func(tri [][2]float64) {
b.fillTriangle(tri, func(x, y int) {
if b.clip.AlphaAt(x, y).A == 0 {
return
}
if b.mask.AlphaAt(x, y).A > 0 {
return
}
b.mask.SetAlpha(x, y, color.Alpha{A: 255})
b.Image.SetRGBA(x, y, mix(style.Color, b.Image.RGBAAt(x, y)))
})
})
}
func (b *SoftwareBackend) FillImageMask(style *backendbase.FillStyle, mask *image.Alpha, pts [4][2]float64) {
mw := float64(mask.Bounds().Dx())
mh := float64(mask.Bounds().Dy())
b.fillQuad(pts, func(x, y int, sx2, sy2 float64) {
sxi := int(mw * sx2)
syi := int(mh * sy2)
a := mask.AlphaAt(sxi, syi)
if a.A == 0 {
return
}
b.Image.SetRGBA(x, y, alphaColor(style.Color, a))
})
}
func (b *SoftwareBackend) ClearClip() {
p := b.clip.Pix
for i := range p {
p[i] = 255
}
}
func (b *SoftwareBackend) Clip(pts [][2]float64) {
p2 := b.mask.Pix
for i := range p2 {
p2[i] = 0
}
iterateTriangles(pts[:], func(tri [][2]float64) {
b.fillTriangle(tri, func(x, y int) {
b.mask.SetAlpha(x, y, color.Alpha{A: 255})
})
})
p := b.clip.Pix
for i := range p {
if p2[i] == 0 {
p[i] = 0
}
}
}