public static Hsl FromRgb(Rgb rgb)
{
const float MaxDivisor = 255.0f;
var hsl = new Hsl();
float red = rgb.Red / MaxDivisor;
float green = rgb.Green / MaxDivisor;
float blue = rgb.Blue / MaxDivisor;
float min = Math.Min(Math.Min(red, green), blue);
float max = Math.Max(Math.Max(red, green), blue);
float diff = max - min;
hsl.Luminance = (max + min) / 2;
if (!diff.Equals(0))
{
hsl.Saturation = (hsl.Luminance <= 0.5) ? (diff / (max + min)) : (diff / (2 - max - min));
float hue;
if (red.Equals(max))
{
hue = ((green - blue) / 6) / diff;
}
else if (green.Equals(max))
{
hue = (1.0f / 3) + ((blue - red) / 6) / diff;
}
else
{
hue = (2.0f / 3) + ((red - green) / 6) / diff;
}
if (hue < 0)
{
hue += 1;
}
if (hue > 1)
{
hue -= 1;
}
hsl.Hue = (int)(hue * 360);
}
return hsl;
}
public static Hsl FromRgb(Rgb rgb)
{
const float MaxDivisor = 255.0f;
var hsl = new Hsl();
float red = rgb.Red / MaxDivisor;
float green = rgb.Green / MaxDivisor;
float blue = rgb.Blue / MaxDivisor;
float min = Math.Min(Math.Min(red, green), blue);
float max = Math.Max(Math.Max(red, green), blue);
float diff = max - min;
hsl.Luminance = (max + min) / 2;
if (!diff.Equals(0))
{
hsl.Saturation = (hsl.Luminance <= 0.5) ? (diff / (max + min)) : (diff / (2 - max - min));
float hue;
if (red.Equals(max))
{
hue = ((green - blue) / 6) / diff;
}
else if (green.Equals(max))
{
hue = (1.0f / 3) + ((blue - red) / 6) / diff;
}
else
{
hue = (2.0f / 3) + ((red - green) / 6) / diff;
}
if (hue < 0)
{
hue += 1;
}
if (hue > 1)
{
hue -= 1;
}
hsl.Hue = (int)(hue * 360);
}
return(hsl);
}
public static Rgb ToRgb(Hsl hsl)
{
var rgb = new Rgb();
if (hsl.Saturation == 0)
{
rgb.Red = rgb.Green = rgb.Blue = (byte)(hsl.Luminance * 255);
}
else
{
float v1, v2;
float hue = (float)hsl.Hue / 360;
v2 = (hsl.Luminance < 0.5)
? (hsl.Luminance * (1 + hsl.Saturation))
: ((hsl.Luminance + hsl.Saturation) - (hsl.Luminance * hsl.Saturation));
v1 = 2 * hsl.Luminance - v2;
rgb.Red = (byte)(255 * HueToRgb(v1, v2, hue + (1.0f / 3)));
rgb.Green = (byte)(255 * HueToRgb(v1, v2, hue));
rgb.Blue = (byte)(255 * HueToRgb(v1, v2, hue - (1.0f / 3)));
rgb.Alpha = 255;
}
return rgb;
}
