Move RLE decoding into a separate package

internal/conv/object.go

@@ -10,6 +10,8 @@ import (
 	"ur.gs/ordoor/internal/data"
 )
 
+var transparent = color.RGBA{0, 0, 0, 0}
+
 // Important conversions:
 //
 //   * Width & height now stored using int
@@ -46,57 +48,18 @@ func ConvertObject(rawObj *data.Object, name string) *Object {
 	return out
 }
 
-var transparent = color.RGBA{0, 0, 0, 0}
-
-// WIP. Try to convert the pixeldata into a picture.
 func spriteToPic(name string, idx int, sprite *data.Sprite) *pixel.PictureData {
 	pic := pixel.MakePictureData(pixel.R(float64(0), float64(0), float64(sprite.Width), float64(sprite.Height)))
+	width := int(sprite.Width)
+	height := int(sprite.Height)
 
-	log.Printf("%v %v: width=%v height=%v", name, idx, sprite.Width, sprite.Height)
+	log.Printf("%v %v: width=%v height=%v", name, idx, width, height)
 
-	for y := 0; y < int(sprite.Height); y++ {
-		encoded := sprite.Rows[y]
-		decoded := make([]byte, 0, int(sprite.Width))
+	for y := 0; y < height; y++ {
+		for x := 0; x < width; x++ {
+			b := sprite.Data[y*width+x]
 
-		// Start with all bytes transparent
-		for x := 0; x < int(sprite.Width); x++ {
-			pic.Pix[pic.Index(pixel.V(float64(x), float64(y)))] = transparent
-		}
-
-		for i := 0; i < len(encoded); i++ {
-			b := encoded[i]
-
-			// This appears to be a kind of RLE
-			if b == 0 {
-				continue // finished
-			} else if b < 0x80 {
-				// repeat the next byte this many times
-				for j := 0; j < int(b); j++ {
-					decoded = append(decoded, encoded[i+1])
-				}
-
-				i++ // skip the repeat byte
-			} else if b == 0x80 {
-				// transparent value, skip forward *x+1 rows
-				skip := int(encoded[i+1])
-				for i := 0; i < skip; i++ {
-					decoded = append(decoded, byte(0x00))
-				}
-
-				i++ // skip the count byte
-			} else {
-				// take the next b-0x80 bytes literally
-				literals := int(b) - 0x80
-				for j := i + 1; j <= i+literals; j++ {
-					decoded = append(decoded, encoded[j])
-				}
-
-				i = i + literals
-			}
-		}
-
-		// Update the picture
-		for x, b := range decoded {
+			// Update the picture
 			if err := setPaletteColor(pic, x, y, b); err != nil {
 				log.Printf("%s %d: %d,%d: %v", name, idx, x, y, err)
 			}