public static void SplitRgb5A3(
ushort color,
out byte r,
out byte g,
out byte b,
out byte a)
{
var alphaFlag = BitLogic.ExtractFromRight(color, 15, 1);
if (alphaFlag == 1)
{
a = 255;
r = ColorUtil.ExtractScaled(color, 10, 5);
g = ColorUtil.ExtractScaled(color, 5, 5);
b = ColorUtil.ExtractScaled(color, 0, 5);
}
else
{
a = ColorUtil.ExtractScaled(color, 12, 3);
r = ColorUtil.ExtractScaled(color, 8, 4, 17);
g = ColorUtil.ExtractScaled(color, 4, 4, 17);
b = ColorUtil.ExtractScaled(color, 0, 4, 17);
}
}
public static byte ExtractScaled(
ushort col,
int offset,
int count,
double factor)
{
var extracted = BitLogic.ExtractFromRight(col, offset, count) * 1d;
return((byte)Math.Round(extracted * factor));
}
protected override IColor[] DecodeBlock(IList <byte> block, int position)
{
var bl = new IColor[4 * 4];
var s = new VectorReader(block, position, Endianness.Big);
for (var j = 0; j < 4; ++j)
{
for (var i = 0; i < 4; ++i)
{
var pix = s.ReadU16();
var alphaFlag = BitLogic.ExtractFromRight(pix, 15, 1);
byte r, g, b, a;
if (alphaFlag == 1)
{
a = 255;
r = ColorUtil.ExtractScaled(pix, 10, 5);
g = ColorUtil.ExtractScaled(pix, 5, 5);
b = ColorUtil.ExtractScaled(pix, 0, 5);
}
else
{
a = ColorUtil.ExtractScaled(pix, 12, 3);
r = ColorUtil.ExtractScaled(pix, 8, 4, 17);
g = ColorUtil.ExtractScaled(pix, 4, 4, 17);
b = ColorUtil.ExtractScaled(pix, 0, 4, 17);
}
bl[j * 4 + i] = ColorImpl.FromRgbaBytes(r, g, b, a);
}
}
return(bl);
}