public Composition(int width, int height, ushort bitsPerPixel)
{
DeviceContext = Gdi32.CreateCompatibleDC(IntPtr.Zero).ThrowWithoutLastErrorAvailableIfInvalid(nameof(Gdi32.CreateCompatibleDC));
bitmap = Gdi32.CreateDIBSection(DeviceContext, new()
{
bmiHeader =
{
biSize = Marshal.SizeOf <Gdi32.BITMAPINFOHEADER>(),
biWidth = width,
biHeight = -height,
biPlanes = 1,
biBitCount = bitsPerPixel,
},
}, Gdi32.DIB.RGB_COLORS, out var compositionPixelDataPointer, hSection: IntPtr.Zero, offset: 0).ThrowLastErrorIfInvalid();
Gdi32.SelectObject(DeviceContext, bitmap).ThrowWithoutLastErrorAvailableIfInvalid(nameof(Gdi32.SelectObject));
unsafe
{
Pixels = new(
(byte *)compositionPixelDataPointer,
(uint)width,
stride : ((((uint)width * 3) + 3) / 4) * 4,
(uint)height);
}
}
// Referenced http://inis.jinr.ru/sl/vol1/CMC/Graphics_Gems_2,ed_J.Arvo.pdf and
// https://github.com/JeremyAnsel/JeremyAnsel.ColorQuant/blob/a025932f7ec361337aaab3057608ed0f71e4e781/JeremyAnsel.ColorQuant/JeremyAnsel.ColorQuant/WuColorQuantizer.cs
// to help figure out what was going on.
public void Quantize(
ColorEnumerable sourceImage,
(byte R, byte G, byte B)[] paletteBuffer,