package aseprite

import (

"encoding/binary"

"image"

"image/color"

"image/draw"

)

func expandSliceKey(slice *Slice, lenFrames int, frameIndices []int) {

if len(slice.Frames) == lenFrames {

return

}

expandedKeys := make([]SliceFrame, lenFrames)

keyIdx := 0

var current SliceFrame

if len(slice.Frames) > 0 {

current = slice.Frames[0]

}

for frameIdx := range expandedKeys {

if keyIdx < len(slice.Frames) && frameIndices[keyIdx] == frameIdx {

current = slice.Frames[keyIdx]

keyIdx++

}

expandedKeys[frameIdx] = current

}

slice.Frames = expandedKeys

}

func skipString(raw []byte) []byte {

n := binary.LittleEndian.Uint16(raw)

return raw[2+n:]

}

func parseString(raw []byte) string {

n := binary.LittleEndian.Uint16(raw)

return string(raw[2 : 2+n])

}

func parseColor(raw []byte) color.NRGBA {

return color.NRGBA{

R: raw[0],

G: raw[1],

B: raw[2],

A: raw[3],

}

}

func drawTile(dst draw.Image, src image.Image, x, y int, flags FlipBitMask) {

bounds := src.Bounds()

w, h := bounds.Dx(), bounds.Dy()

for dy := range h {

for dx := range w {

sx, sy := dx, dy

if flags.IsFlipX() {

sx = w - 1 - sx

}

if flags.IsFlipY() {

sy = h - 1 - sy

}

if flags.IsFlipD() {

sx, sy = sy, sx

}

c := src.At(bounds.Min.X+sx, bounds.Min.Y+sy)

dst.Set(x+dx, y+dy, c)

}

}

}