Use bytes for r, g and b

box.go

@@ -15,7 +15,7 @@ import (
 type Box struct {
 	x, y       int
 	w, h       int
-	r, g, b, a int
+	r, g, b, a byte
 }
 
 // CreateRandomBox randomly searches for a place for a 1x1 size box.
@@ -24,7 +24,8 @@ type Box struct {
 func (pi *PixelImage) CreateRandomBox(checkIfPossible bool) *Box {
 	w := 1
 	h := 1
-	var x, y, r, g, b, a int
+	var x, y int
+	var r, g, b, a byte
 	for !checkIfPossible || !pi.Done(0, 0) {
 		// Find a random placement for (x,y), for a box of size (1,1)
 		x = rand.Intn(pi.w)
@@ -155,16 +156,16 @@ func (pi *PixelImage) Expand(bo *Box) (expanded bool) {
 
 // singleHex returns a single digit hex number, as a string
 // the numbers are not rounded, just floored
-func singleHex(x int) string {
+func singleHex(x byte) string {
 	hex := strconv.FormatInt(int64(x), 16)
-	if len(hex) == 1 {
-		return "0"
+	if len(hex) < 2 {
+		return "0" + hex // Prepend "0" if the hex representation is a single digit
 	}
-	return string(hex[0])
+	return hex
 }
 
 // shortColorString returns a string representing a color on the short form "#000"
-func shortColorString(r, g, b int) string {
+func shortColorString(r, g, b byte) string {
 	return "#" + singleHex(r) + singleHex(g) + singleHex(b)
 }
 
@@ -186,7 +187,7 @@ func (pi *PixelImage) CoverBox(bo *Box, pink bool, optimizeColors bool) {
 	} else if optimizeColors {
 		colorString = shortColorString(bo.r, bo.g, bo.b)
 	} else {
-		colorString = string(tinysvg.ColorBytes(bo.r, bo.g, bo.b))
+		colorString = string(tinysvg.ColorBytes(int(bo.r), int(bo.g), int(bo.b)))
 	}
 
 	// Set the fill color

pixelimage.go

@@ -19,10 +19,10 @@ import (
 type Pixel struct {
 	x       int
 	y       int
-	r       int
-	g       int
-	b       int
-	a       int
+	r       byte
+	g       byte
+	b       byte
+	a       byte
 	covered bool
 }
 
@@ -107,10 +107,10 @@ func NewPixelImage(img image.Image, verbose bool) *PixelImage {
 
 		for x := img.Bounds().Min.X; x < img.Bounds().Max.X; x++ {
 			c = color.NRGBAModel.Convert(img.At(x, y)).(color.NRGBA)
-			alpha := int(c.A)
+			alpha := byte(c.A)
 			// Mark transparent pixels as already being "covered"
 			covered := alpha == 0
-			pixels[i] = &Pixel{x, y, int(c.R), int(c.G), int(c.B), alpha, covered}
+			pixels[i] = &Pixel{x, y, byte(c.R), byte(c.G), byte(c.B), alpha, covered}
 			i++
 		}
 	}
@@ -143,7 +143,7 @@ func (pi *PixelImage) Done(startx, starty int) bool {
 }
 
 // At returns the RGB color at the given coordinate
-func (pi *PixelImage) At(x, y int) (r, g, b int) {
+func (pi *PixelImage) At(x, y int) (r, g, b byte) {
 	i := y*pi.w + x
 	//if i >= len(pi.pixels) {
 	//	panic("At out of bounds, too large coordinate")
@@ -153,7 +153,7 @@ func (pi *PixelImage) At(x, y int) (r, g, b int) {
 }
 
 // At2 returns the RGBA color at the given coordinate
-func (pi *PixelImage) At2(x, y int) (r, g, b, a int) {
+func (pi *PixelImage) At2(x, y int) (r, g, b, a byte) {
 	i := y*pi.w + x
 	//if i >= len(pi.pixels) {
 	//	panic("At out of bounds, too large coordinate")
@@ -175,7 +175,7 @@ func (pi *PixelImage) CoverAllPixels() {
 	coverCount := 0
 	for _, p := range pi.pixels {
 		if !(*p).covered {
-			pi.svgTag.Pixel((*p).x, (*p).y, (*p).r, (*p).g, (*p).b)
+			pi.svgTag.Pixel((*p).x, (*p).y, int((*p).r), int((*p).g), int((*p).b))
 			(*p).covered = true
 			coverCount++
 		}
@@ -194,7 +194,7 @@ func (pi *PixelImage) CoverAllPixelsCallback(callbackFunc func(int, int), Nth in
 	callbackFunc(0, l)
 	for i, p := range pi.pixels {
 		if !(*p).covered {
-			pi.svgTag.Pixel((*p).x, (*p).y, (*p).r, (*p).g, (*p).b)
+			pi.svgTag.Pixel((*p).x, (*p).y, int((*p).r), int((*p).g), int((*p).b))
 			(*p).covered = true
 			coverCount++
 		}