// https://en.wikipedia.org/wiki/Floyd%E2%80%93Steinberg_dithering
public static void FloydSteinberg(
Color32[] pixels,
System.Func <Color32, Color32> encode,
int width,
int height)
{
ColorInt e, e7, e5, e3, e1;
e = e7 = e5 = e3 = e1 = new ColorInt();
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
var c0 = pixels[(y * width) + x];
var c1 = encode(c0);
pixels[(y * width) + x] = c1;
e.AddDiff(ref c0, ref c1);
e7.SetMulDiv(ref e, 7, 16);
e5.SetMulDiv(ref e, 5, 16);
e3.SetMulDiv(ref e, 3, 16);
e1.SetMulDiv(ref e, 1, 16);
if ((x + 1) < width)
{
AddColor(ref pixels[(y * width) + (x + 1)], ref e7);
if ((y + 1) < height)
{
AddColor(ref pixels[((y + 1) * width) + (x + 1)], ref e1);
}
}
if ((y + 1) < height)
{
if ((x - 1) >= 0)
{
AddColor(ref pixels[((y + 1) * width) + (x - 1)], ref e3);
}
AddColor(ref pixels[((y + 1) * width) + x], ref e5);
}
e.Sub(ref e7);
e.Sub(ref e5);
e.Sub(ref e3);
e.Sub(ref e1);
}
}
}
