aw/go-resize
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Extract method "resizeSlice" to reduce duplicate code.

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This commit is contained in:
jst 2014-01-17 19:05:30 +01:00
parent f8ec710330
commit 7c5018c82b
1 changed files with 30 additions and 48 deletions
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78
resize.go
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@ -59,31 +59,9 @@ func Resize(width, height uint, img image.Image, interp InterpolationFunction) i
n := numJobs(b.Dy())
c := make(chan int, n)
for i := 0; i < n; i++ {
go func(b image.Rectangle, c chan int) {
filter := interp(img, float32(clampFactor(scaleX)))
var u float32
var color color.RGBA64
for y := b.Min.Y; y < b.Max.Y; y++ {
for x := b.Min.X; x < b.Max.X; x++ {
u = scaleX*(float32(y)+adjust) + float32(oldBounds.Min.X)
color = filter.Interpolate(u, x)
i := tempImg.PixOffset(x, y)
tempImg.Pix[i+0] = uint8(color.R >> 8)
tempImg.Pix[i+1] = uint8(color.R)
tempImg.Pix[i+2] = uint8(color.G >> 8)
tempImg.Pix[i+3] = uint8(color.G)
tempImg.Pix[i+4] = uint8(color.B >> 8)
tempImg.Pix[i+5] = uint8(color.B)
tempImg.Pix[i+6] = uint8(color.A >> 8)
tempImg.Pix[i+7] = uint8(color.A)
}
}
c <- 1
}(image.Rect(b.Min.X, b.Min.Y+i*(b.Dy())/n, b.Max.X, b.Min.Y+(i+1)*(b.Dy())/n), c)
slice := image.Rect(b.Min.X, b.Min.Y+i*(b.Dy())/n, b.Max.X, b.Min.Y+(i+1)*(b.Dy())/n)
go resizeSlice(img, tempImg, interp, scaleX, adjust, float32(oldBounds.Min.X), slice, c)
}
for i := 0; i < n; i++ {
<-c
}
@ -93,31 +71,9 @@ func Resize(width, height uint, img image.Image, interp InterpolationFunction) i
adjust = 0.5 * ((oldHeight-1.0)/scaleY - float32(b.Dy()-1))
for i := 0; i < n; i++ {
go func(b image.Rectangle, c chan int) {
filter := interp(tempImg, float32(clampFactor(scaleY)))
var u float32
var color color.RGBA64
for y := b.Min.Y; y < b.Max.Y; y++ {
for x := b.Min.X; x < b.Max.X; x++ {
u = scaleY*(float32(y)+adjust) + float32(oldBounds.Min.Y)
color = filter.Interpolate(u, x)
i := resultImg.PixOffset(x, y)
resultImg.Pix[i+0] = uint8(color.R >> 8)
resultImg.Pix[i+1] = uint8(color.R)
resultImg.Pix[i+2] = uint8(color.G >> 8)
resultImg.Pix[i+3] = uint8(color.G)
resultImg.Pix[i+4] = uint8(color.B >> 8)
resultImg.Pix[i+5] = uint8(color.B)
resultImg.Pix[i+6] = uint8(color.A >> 8)
resultImg.Pix[i+7] = uint8(color.A)
}
}
c <- 1
}(image.Rect(b.Min.X, b.Min.Y+i*(b.Dy())/n, b.Max.X, b.Min.Y+(i+1)*(b.Dy())/n), c)
slice := image.Rect(b.Min.X, b.Min.Y+i*(b.Dy())/n, b.Max.X, b.Min.Y+(i+1)*(b.Dy())/n)
go resizeSlice(tempImg, resultImg, interp, scaleY, adjust, float32(oldBounds.Min.Y), slice, c)
}
for i := 0; i < n; i++ {
<-c
}
@ -125,6 +81,32 @@ func Resize(width, height uint, img image.Image, interp InterpolationFunction) i
return resultImg
}
// Resize a rectangle image slice
func resizeSlice(input image.Image, output *image.RGBA64, interp InterpolationFunction, scale, adjust, offset float32, slice image.Rectangle, c chan int) {
filter := interp(input, float32(clampFactor(scale)))
var u float32
var color color.RGBA64
for y := slice.Min.Y; y < slice.Max.Y; y++ {
for x := slice.Min.X; x < slice.Max.X; x++ {
u = scale*(float32(y)+adjust) + offset
color = filter.Interpolate(u, x)
i := output.PixOffset(x, y)
output.Pix[i+0] = uint8(color.R >> 8)
output.Pix[i+1] = uint8(color.R)
output.Pix[i+2] = uint8(color.G >> 8)
output.Pix[i+3] = uint8(color.G)
output.Pix[i+4] = uint8(color.B >> 8)
output.Pix[i+5] = uint8(color.B)
output.Pix[i+6] = uint8(color.A >> 8)
output.Pix[i+7] = uint8(color.A)
}
}
c <- 1
}
// Calculate scaling factors using old and new image dimensions.
func calcFactors(width, height uint, oldWidth, oldHeight float32) (scaleX, scaleY float32) {
if width == 0 {