private Color CreateColor(long value, int redBitMask, int greenBitMask, int redShift)
{
return(Color.FromArgb(
255,
(RedDepth == 0) ? 255 : Convert.ChangeBitDepth((int)(value >> redShift & redBitMask), RedDepth, 8),
(GreenDepth == 0) ? 255 : Convert.ChangeBitDepth((int)(value & greenBitMask), GreenDepth, 8),
255));
}
private Color CreateColor(long value, int alphaBitMask, int lumBitMask, int lumShift)
{
return(Color.FromArgb(
(AlphaDepth == 0) ? 255 : Convert.ChangeBitDepth((int)(value & alphaBitMask), AlphaDepth, 8),
(LuminenceDepth == 0) ? 255 : Convert.ChangeBitDepth((int)(value >> lumShift & lumBitMask), LuminenceDepth, 8),
(LuminenceDepth == 0) ? 255 : Convert.ChangeBitDepth((int)(value >> lumShift & lumBitMask), LuminenceDepth, 8),
(LuminenceDepth == 0) ? 255 : Convert.ChangeBitDepth((int)(value >> lumShift & lumBitMask), LuminenceDepth, 8)));
}
public byte[] Save(IEnumerable <Color> colors)
{
byte nibbleBuffer = 0;
bool writeNibble = false;
var ms = new MemoryStream();
using (var bw = new BinaryWriter(ms, System.Text.Encoding.ASCII, true))
{
foreach (var color in colors)
{
var r = (RedDepth == 0) ? 0 : Convert.ChangeBitDepth(color.R, 8, RedDepth);
var g = (GreenDepth == 0) ? 0 : Convert.ChangeBitDepth(color.G, 8, GreenDepth);
var rShift = GreenDepth;
long value = g;
value |= (uint)(r << rShift);
switch (BitDepth)
{
case 4:
if (writeNibble)
{
nibbleBuffer |= (byte)(value & 0xF);
bw.Write(nibbleBuffer);
}
else
{
nibbleBuffer = (byte)((value & 0xF) << 4);
}
writeNibble = !writeNibble;
break;
case 8:
bw.Write((byte)value);
break;
case 16:
bw.Write(Convert.ToByteArray((ushort)value, 2, ByteOrder));
break;
default:
throw new InvalidOperationException($"BitDepth {BitDepth} not supported!");
}
}
if (writeNibble)
{
bw.Write(nibbleBuffer);
}
}
return(ms.ToArray());
}
/// <inheritdoc cref="IIndexEncoding.Quantize(IEnumerable{Color},QuantizationSettings)"/>
public (IEnumerable <IndexData> indices, IList <Color> palette) Quantize(IEnumerable <Color> colors, QuantizationSettings settings)
{
if (settings.ColorModel == ColorModel.RGBA)
{
settings.ColorModel = ColorModel.RGB;
}
var colorList = colors.ToList();
var(indices, palette) = Kolors.Quantize(colorList, settings);
var alphaIndexData = indices.
Zip(colorList, (x, y) => new { index = x, alpha = y.A }).
Select(x => new AlphaIndexData(Convert.ChangeBitDepth(x.alpha, 8, _alphaDepth), x.index));
return(alphaIndexData, palette);
}
/// <inheritdoc cref="IIndexEncoding.Load(byte[])"/>
public IEnumerable <IndexData> Load(byte[] input)
{
var alphaShift = _indexDepth;
var indexBitMask = (1 << _indexDepth) - 1;
using (var br = new BinaryReader(new MemoryStream(input)))
while (br.BaseStream.Position < br.BaseStream.Length)
{
switch (_bitDepth)
{
case 8:
var value = br.ReadByte();
yield return(new AlphaIndexData(
Convert.ChangeBitDepth(value >> alphaShift, _alphaDepth, 8),
value & indexBitMask));
break;
default:
throw new InvalidOperationException($"IndexDepth {_indexDepth} not supported.");
}
}
}
private static ushort From565To555(ushort value) => (ushort)(value & 0x1F | (Convert.ChangeBitDepth((value >> 5) & 0x3F, 6, 5) << 5) | (((value >> 11) & 0x1F) << 10));