/// <summary>
/// Converts a WPF HSL color to an RGB color
/// </summary>
/// <param name="hlsColor">The HSL color to convert.</param>
/// <returns>An RGB color object equivalent to the HSL color object passed in.</returns>
public static Color HlsToRgb(HlsColor hlsColor)
{
// Initialize result
var rgbColor = new Color();
/* If S = 0, that means we are dealing with a shade
* of gray. So, we set R, G, and B to L and exit. */
// Special case: Gray
if (hlsColor.S == 0)
{
rgbColor.R = (byte)(hlsColor.L * 255);
rgbColor.G = (byte)(hlsColor.L * 255);
rgbColor.B = (byte)(hlsColor.L * 255);
rgbColor.A = (byte)(hlsColor.A * 255);
return(rgbColor);
}
double t1;
if (hlsColor.L < 0.5)
{
t1 = hlsColor.L * (1.0 + hlsColor.S);
}
else
{
t1 = hlsColor.L + hlsColor.S - (hlsColor.L * hlsColor.S);
}
var t2 = 2.0 * hlsColor.L - t1;
// Convert H from degrees to a percentage
var h = hlsColor.H / 360;
// Set colors as percentage values
var tR = h + (1.0 / 3.0);
var r = SetColor(t1, t2, tR);
var tG = h;
var g = SetColor(t1, t2, tG);
var tB = h - (1.0 / 3.0);
var b = SetColor(t1, t2, tB);
// Assign colors to Color object
rgbColor.R = (byte)(r * 255);
rgbColor.G = (byte)(g * 255);
rgbColor.B = (byte)(b * 255);
rgbColor.A = (byte)(hlsColor.A * 255);
// Set return value
return(rgbColor);
}
/// <summary>
/// Converts a WPF RGB color to an HSL color
/// </summary>
/// <param name="rgbColor">The RGB color to convert.</param>
/// <returns>An HSL color object equivalent to the RGB color object passed in.</returns>
public static HlsColor RgbToHls(Color rgbColor)
{
// Initialize result
var hlsColor = new HlsColor();
// Convert RGB values to percentages
double r = (double)rgbColor.R / 255;
var g = (double)rgbColor.G / 255;
var b = (double)rgbColor.B / 255;
var a = (double)rgbColor.A / 255;
// Find min and max RGB values
var min = Math.Min(r, Math.Min(g, b));
var max = Math.Max(r, Math.Max(g, b));
var delta = max - min;
/* If max and min are equal, that means we are dealing with
* a shade of gray. So we set H and S to zero, and L to either
* max or min (it doesn't matter which), and then we exit. */
//Special case: Gray
if (max == min)
{
hlsColor.H = 0;
hlsColor.S = 0;
hlsColor.L = max;
return(hlsColor);
}
/* If we get to this point, we know we don't have a shade of gray. */
// Set L
hlsColor.L = (min + max) / 2;
// Set S
if (hlsColor.L < 0.5)
{
hlsColor.S = delta / (max + min);
}
else
{
hlsColor.S = delta / (2.0 - max - min);
}
// Set H
if (r == max)
{
hlsColor.H = (g - b) / delta;
}
if (g == max)
{
hlsColor.H = 2.0 + (b - r) / delta;
}
if (b == max)
{
hlsColor.H = 4.0 + (r - g) / delta;
}
hlsColor.H *= 60;
if (hlsColor.H < 0)
{
hlsColor.H += 360;
}
// Set A
hlsColor.A = a;
// Set return value
return(hlsColor);
}