forked from disintegration/imaging
/
transform.go
145 lines (109 loc) · 3.23 KB
/
transform.go
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package imaging
import (
"image"
)
// Rotate90 rotates the image 90 degrees counterclockwise and returns the transformed image.
func Rotate90(img image.Image) *image.NRGBA {
src := toNRGBA(img)
srcW := src.Bounds().Max.X
srcH := src.Bounds().Max.Y
dstW := srcH
dstH := srcW
dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
parallel(dstH, func(partStart, partEnd int) {
for dstY := partStart; dstY < partEnd; dstY++ {
for dstX := 0; dstX < dstW; dstX++ {
srcX := dstH - dstY - 1
srcY := dstX
srcOff := srcY*src.Stride + srcX*4
dstOff := dstY*dst.Stride + dstX*4
copy(dst.Pix[dstOff:dstOff+4], src.Pix[srcOff:srcOff+4])
}
}
})
return dst
}
// Rotate180 rotates the image 180 degrees counterclockwise and returns the transformed image.
func Rotate180(img image.Image) *image.NRGBA {
src := toNRGBA(img)
srcW := src.Bounds().Max.X
srcH := src.Bounds().Max.Y
dstW := srcW
dstH := srcH
dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
parallel(dstH, func(partStart, partEnd int) {
for dstY := partStart; dstY < partEnd; dstY++ {
for dstX := 0; dstX < dstW; dstX++ {
srcX := dstW - dstX - 1
srcY := dstH - dstY - 1
srcOff := srcY*src.Stride + srcX*4
dstOff := dstY*dst.Stride + dstX*4
copy(dst.Pix[dstOff:dstOff+4], src.Pix[srcOff:srcOff+4])
}
}
})
return dst
}
// Rotate270 rotates the image 270 degrees counterclockwise and returns the transformed image.
func Rotate270(img image.Image) *image.NRGBA {
src := toNRGBA(img)
srcW := src.Bounds().Max.X
srcH := src.Bounds().Max.Y
dstW := srcH
dstH := srcW
dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
parallel(dstH, func(partStart, partEnd int) {
for dstY := partStart; dstY < partEnd; dstY++ {
for dstX := 0; dstX < dstW; dstX++ {
srcX := dstY
srcY := dstW - dstX - 1
srcOff := srcY*src.Stride + srcX*4
dstOff := dstY*dst.Stride + dstX*4
copy(dst.Pix[dstOff:dstOff+4], src.Pix[srcOff:srcOff+4])
}
}
})
return dst
}
// FlipH flips the image horizontally (from left to right) and returns the transformed image.
func FlipH(img image.Image) *image.NRGBA {
src := toNRGBA(img)
srcW := src.Bounds().Max.X
srcH := src.Bounds().Max.Y
dstW := srcW
dstH := srcH
dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
parallel(dstH, func(partStart, partEnd int) {
for dstY := partStart; dstY < partEnd; dstY++ {
for dstX := 0; dstX < dstW; dstX++ {
srcX := dstW - dstX - 1
srcY := dstY
srcOff := srcY*src.Stride + srcX*4
dstOff := dstY*dst.Stride + dstX*4
copy(dst.Pix[dstOff:dstOff+4], src.Pix[srcOff:srcOff+4])
}
}
})
return dst
}
// FlipV flips the image vertically (from top to bottom) and returns the transformed image.
func FlipV(img image.Image) *image.NRGBA {
src := toNRGBA(img)
srcW := src.Bounds().Max.X
srcH := src.Bounds().Max.Y
dstW := srcW
dstH := srcH
dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
parallel(dstH, func(partStart, partEnd int) {
for dstY := partStart; dstY < partEnd; dstY++ {
for dstX := 0; dstX < dstW; dstX++ {
srcX := dstX
srcY := dstH - dstY - 1
srcOff := srcY*src.Stride + srcX*4
dstOff := dstY*dst.Stride + dstX*4
copy(dst.Pix[dstOff:dstOff+4], src.Pix[srcOff:srcOff+4])
}
}
})
return dst
}