Refactoring

resize.go

@@ -30,16 +30,6 @@ import (
 	"runtime"
 )
 
-// Trans2 is a 2-dimensional linear transformation.
-type Trans2 [6]float32
-
-// Apply the transformation to a point (x,y).
-func (t *Trans2) Eval(x, y float32) (u, v float32) {
-	u = t[0]*x + t[1]*y + t[2]
-	v = t[3]*x + t[4]*y + t[5]
-	return
-}
-
 // Filter can interpolate at points (x,y)
 type Filter interface {
 	Interpolate(u float32, y int) color.RGBA64
@@ -60,15 +50,11 @@ func Resize(width, height uint, img image.Image, interp InterpolationFunction) i
 	oldBounds := img.Bounds()
 	oldWidth := float32(oldBounds.Dx())
 	oldHeight := float32(oldBounds.Dy())
-
 	scaleX, scaleY := calcFactors(width, height, oldWidth, oldHeight)
-	t := Trans2{scaleX, 0, float32(oldBounds.Min.X), 0, scaleY, float32(oldBounds.Min.Y)}
 
-	//resizedImg := image.NewRGBA64(image.Rect(0, 0, int(0.7+oldWidth/scaleX), int(0.7+oldHeight/scaleY)))
-	resizedImg := image.NewRGBA64(image.Rect(0, 0, oldBounds.Dy(), int(0.7+oldWidth/scaleX)))
-	b := resizedImg.Bounds()
-	adjustX := 0.5 * ((oldWidth-1.0)/scaleX - float32(b.Dy()-1))
-	//adjustY := 0.5 * ((oldHeight-1.0)/scaleY - float32(b.Dy()-1))
+	tempImg := image.NewRGBA64(image.Rect(0, 0, oldBounds.Dy(), int(0.7+oldWidth/scaleX)))
+	b := tempImg.Bounds()
+	adjust := 0.5 * ((oldWidth-1.0)/scaleX - float32(b.Dy()-1))
 
 	n := numJobs(b.Dy())
 	c := make(chan int, n)
@@ -79,19 +65,19 @@ func Resize(width, height uint, img image.Image, interp InterpolationFunction) i
 			var color color.RGBA64
 			for y := b.Min.X; y < b.Max.X; y++ {
 				for x := b.Min.Y; x < b.Max.Y; x++ {
-					u = t[0]*(float32(x)+adjustX) + t[2]
+					u = scaleX*(float32(x)+adjust) + float32(oldBounds.Min.X)
 
 					color = filter.Interpolate(u, y)
 
-					i := resizedImg.PixOffset(y, x)
-					resizedImg.Pix[i+0] = uint8(color.R >> 8)
-					resizedImg.Pix[i+1] = uint8(color.R)
-					resizedImg.Pix[i+2] = uint8(color.G >> 8)
-					resizedImg.Pix[i+3] = uint8(color.G)
-					resizedImg.Pix[i+4] = uint8(color.B >> 8)
-					resizedImg.Pix[i+5] = uint8(color.B)
-					resizedImg.Pix[i+6] = uint8(color.A >> 8)
-					resizedImg.Pix[i+7] = uint8(color.A)
+					i := tempImg.PixOffset(y, x)
+					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
@@ -104,16 +90,16 @@ func Resize(width, height uint, img image.Image, interp InterpolationFunction) i
 
 	resultImg := image.NewRGBA64(image.Rect(0, 0, int(0.7+oldWidth/scaleX), int(0.7+oldHeight/scaleY)))
 	b = resultImg.Bounds()
-	adjustX = 0.5 * ((oldWidth-1.0)/scaleX - float32(b.Dx()-1))
+	adjust = 0.5 * ((oldWidth-1.0)/scaleY - float32(b.Dx()-1))
 
 	for i := 0; i < n; i++ {
 		go func(b image.Rectangle, c chan int) {
-			filter := interp(resizedImg, float32(clampFactor(scaleY)))
+			filter := interp(tempImg, float32(clampFactor(scaleY)))
 			var u float32
 			var color color.RGBA64
 			for y := b.Min.X; y < b.Max.X; y++ {
 				for x := b.Min.Y; x < b.Max.Y; x++ {
-					u = t[4]*(float32(x)+adjustX) + t[5]
+					u = scaleY*(float32(x)+adjust) + float32(oldBounds.Min.Y)
 
 					color = filter.Interpolate(u, y)
 
@@ -130,7 +116,6 @@ func Resize(width, height uint, img image.Image, interp InterpolationFunction) i
 			}
 			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)
-
 	}
 
 	for i := 0; i < n; i++ {