static public Rgba32 FromHsl(Hsla32 source)
{
var result = new Rgba32(source.Width, source.Height);
var rgb = result.Data;
var hsl = source.Data;
for (int i = 0; i < hsl.Length; i += 4)
{
rgb[i + Alpha] = (byte)(hsl[i + Hsla32.Alpha] * byte.MaxValue);
var hue = hsl[i + Hsla32.Hue];
var saturation = hsl[i + Hsla32.Saturation];
var lightness = hsl[i + Hsla32.Lightness];
if (Math.Abs(saturation) < 1e-4F)
{
// gray scale
rgb[i + Red] = rgb[i + Green] = rgb[i + Blue] = (byte)(lightness * byte.MaxValue);
}
else
{
var var2 = lightness < 0.5
? lightness * (1.0F + saturation)
: (lightness + saturation) - (saturation * lightness);
var var1 = 2 * lightness - var2;
rgb[i + Red] = (byte)(byte.MaxValue * hue2Rgb(var1, var2, hue + 1F / 3));
rgb[i + Green] = (byte)(byte.MaxValue * hue2Rgb(var1, var2, hue));
rgb[i + Blue] = (byte)(byte.MaxValue * hue2Rgb(var1, var2, hue - 1F / 3));
}
}
return(result);
}
static public Hsla32 FromPbra32(byte[] data, int width)
{
Debug.Assert(data.Length % width == 0);
const int red = Rgba32.Red, green = Rgba32.Green, blue = Rgba32.Blue;
var height = data.Length / width / Rgba32.Dpp;
var result = new Hsla32(width, height);
var hsl = result.Data;
Debug.Assert(hsl.Length == data.Length);
for (int pixel = 0; pixel < data.Length; pixel += Dpp)
{
var realRed = (float)data[pixel + red] / byte.MaxValue;
var realGreen = (float)data[pixel + green] / byte.MaxValue;
var realBlue = (float)data[pixel + blue] / byte.MaxValue;
var minColorness = Math.Min(Math.Min(realRed, realGreen), realBlue);
var maxColorness = Math.Max(Math.Max(realRed, realGreen), realBlue);
var diffColorness = maxColorness - minColorness;
hsl[pixel + Alpha] = (float)data[pixel + Rgba32.Alpha] / byte.MaxValue;
var light = (maxColorness + minColorness) / 2;
hsl[pixel + Lightness] = light;
if (Math.Abs(diffColorness) < 1e-4F)
{
//This is a gray, no chroma...
hsl[pixel + Hue] = hsl[pixel + Saturation] = 0;
}
else
{
//Chromatic data...
hsl[pixel + Saturation] = (light < 0.5)? diffColorness / (maxColorness + minColorness) : diffColorness / (2 - maxColorness - minColorness);
var del_R = (((maxColorness - realRed) / 6) + (diffColorness / 2)) / diffColorness;
var del_G = (((maxColorness - realGreen) / 6) + (diffColorness / 2)) / diffColorness;
var del_B = (((maxColorness - realBlue) / 6) + (diffColorness / 2)) / diffColorness;
if (realRed == maxColorness)
{
hsl[pixel + Hue] = del_B - del_G;
}
else if (realGreen == maxColorness)
{
hsl[pixel + Hue] = 1.0F / 3 + del_R - del_B;
}
else if (realBlue == maxColorness)
{
hsl[pixel + Hue] = 2.0F / 3 + del_G - del_R;
}
if (hsl[pixel + Hue] < 0)
{
hsl[pixel + Hue] += 1.0F;
}
if (hsl[pixel + Hue] > 1)
{
hsl[pixel + Hue] -= 1.0F;
}
}
}
return(result);
}
