move blending functions to separate file, use package const instead of magic number

blendcolor.go

@@ -0,0 +1,35 @@
+package thumbnail
+
+import (
+	"image/color"
+)
+
+func Blend(a, b color.Color) color.Color {
+	switch a.(type) {
+	case color.RGBA:
+		return BlendRGBA(a.(color.RGBA), b.(color.RGBA)) // FIXME there's syntax for this
+
+	case color.YCbCr:
+		return BlendYCbCr(a.(color.YCbCr), b.(color.YCbCr))
+
+	default:
+		return a // ??? unknown color format
+	}
+}
+
+func BlendYCbCr(a, b color.YCbCr) color.YCbCr {
+	return color.YCbCr{
+		Y:  uint8((int(a.Y) + int(b.Y)) / 2),
+		Cb: uint8((int(a.Cb) + int(b.Cb)) / 2),
+		Cr: uint8((int(a.Cr) + int(b.Cr)) / 2),
+	}
+}
+
+func BlendRGBA(a, b color.RGBA) color.RGBA {
+	return color.RGBA{
+		R: uint8((int(a.R) + int(b.R)) / 2),
+		G: uint8((int(a.G) + int(b.G)) / 2),
+		B: uint8((int(a.B) + int(b.B)) / 2),
+		A: uint8((int(a.A) + int(b.A)) / 2),
+	}
+}

image.go

@@ -2,39 +2,10 @@ package thumbnail
 
 import (
 	"image"
-	"image/color"
+
+	"code.ivysaur.me/imagequant"
 )
 
-func Blend(a, b color.Color) color.Color {
-	switch a.(type) {
-	case color.RGBA:
-		return BlendRGBA(a.(color.RGBA), b.(color.RGBA)) // FIXME there's syntax for this
-
-	case color.YCbCr:
-		return BlendYCbCr(a.(color.YCbCr), b.(color.YCbCr))
-
-	default:
-		return a // ??? unknown color format
-	}
-}
-
-func BlendYCbCr(a, b color.YCbCr) color.YCbCr {
-	return color.YCbCr{
-		Y:  uint8((int(a.Y) + int(b.Y)) / 2),
-		Cb: uint8((int(a.Cb) + int(b.Cb)) / 2),
-		Cr: uint8((int(a.Cr) + int(b.Cr)) / 2),
-	}
-}
-
-func BlendRGBA(a, b color.RGBA) color.RGBA {
-	return color.RGBA{
-		R: uint8((int(a.R) + int(b.R)) / 2),
-		G: uint8((int(a.G) + int(b.G)) / 2),
-		B: uint8((int(a.B) + int(b.B)) / 2),
-		A: uint8((int(a.A) + int(b.A)) / 2),
-	}
-}
-
 func (this *Thumbnailer) RenderScaledImage(src image.Image) ([]byte, error) {
 	srcW := src.Bounds().Max.X
 	srcH := src.Bounds().Max.Y
@@ -78,21 +49,5 @@ func (this *Thumbnailer) RenderScaledImage(src image.Image) ([]byte, error) {
 		}
 	}
 
-	/*var b bytes.Buffer*/
+	return crush(dest, imagequant.SPEED_FASTEST)
-
-	return crush(dest, 3)
-
-	/*
-		err := png.Encode(&b, dest)
-		if err != nil {
-			return nil, err
-		}
-	*/
-	/*
-		err := jpeg.Encode(&b, dest, nil)
-		if err != nil {
-			return nil, err
-		}
-
-		return b.Bytes(), nil*/
 }