/// <summary>
/// Converts an RGB color to an HSB color.
/// </summary>
/// <param name="rgbColor">The RGB color to convert.</param>
/// <returns>The HSB color equivalent of the RGBA color passed in.</returns>
/// <remarks>Source: http://msdn.microsoft.com/en-us/library/ms771620.aspx</remarks>
public static HsbColor ToHsb(this Color rgbColor)
{
/* Hue values range between 0 and 360. All
* other values range between 0 and 1. */
// Create HSB color object
var hsbColor = new HsbColor();
// Get RGB color component values
var r = (int)rgbColor.R;
var g = (int)rgbColor.G;
var b = (int)rgbColor.B;
var a = (int)rgbColor.A;
// Get min, max, and delta values
double min = Math.Min(Math.Min(r, g), b);
double max = Math.Max(Math.Max(r, g), b);
double delta = max - min;
/* Black (max = 0) is a special case. We
* simply set HSB values to zero and exit. */
// Black: Set HSB and return
if (max == 0.0)
{
hsbColor.H = 0.0;
hsbColor.S = 0.0;
hsbColor.B = 0.0;
hsbColor.A = a;
return hsbColor;
}
/* Now we process the normal case. */
// Set HSB Alpha value
var alpha = (double)a;
hsbColor.A = alpha / 255;
// Set HSB Hue value
if (r == max) hsbColor.H = (g - b) / delta;
else if (g == max) hsbColor.H = 2 + (b - r) / delta;
else if (b == max) hsbColor.H = 4 + (r - g) / delta;
hsbColor.H *= 60;
if (hsbColor.H < 0.0) hsbColor.H += 360;
// Set other HSB values
hsbColor.S = delta / max;
hsbColor.B = max / 255;
// Set return value
return hsbColor;
}
/// <summary>
/// Converts an RGB color to an HSB color.
/// </summary>
/// <param name="rgbColor">The RGB color to convert.</param>
/// <returns>The HSB color equivalent of the RGBA color passed in.</returns>
/// <remarks>Source: http://msdn.microsoft.com/en-us/library/ms771620.aspx</remarks>
public static HsbColor ToHsb(this Color rgbColor)
{
/* Hue values range between 0 and 360. All
* other values range between 0 and 1. */
// Create HSB color object
var hsbColor = new HsbColor();
// Get RGB color component values
var r = (int)rgbColor.R;
var g = (int)rgbColor.G;
var b = (int)rgbColor.B;
var a = (int)rgbColor.A;
// Get min, max, and delta values
double min = Math.Min(Math.Min(r, g), b);
double max = Math.Max(Math.Max(r, g), b);
double delta = max - min;
/* Black (max = 0) is a special case. We
* simply set HSB values to zero and exit. */
// Black: Set HSB and return
if (max == 0.0)
{
hsbColor.H = 0.0;
hsbColor.S = 0.0;
hsbColor.B = 0.0;
hsbColor.A = a;
return(hsbColor);
}
/* Now we process the normal case. */
// Set HSB Alpha value
var alpha = (double)a;
hsbColor.A = alpha / 255;
// Set HSB Hue value
if (r == max)
{
hsbColor.H = (g - b) / delta;
}
else if (g == max)
{
hsbColor.H = 2 + (b - r) / delta;
}
else if (b == max)
{
hsbColor.H = 4 + (r - g) / delta;
}
hsbColor.H *= 60;
if (hsbColor.H < 0.0)
{
hsbColor.H += 360;
}
// Set other HSB values
hsbColor.S = delta / max;
hsbColor.B = max / 255;
// Set return value
return(hsbColor);
}
/// <summary>
/// Converts an HSB color to an RGB color.
/// </summary>
/// <param name="hsbColor">The HSB color to convert.</param>
/// <returns>The RGB color equivalent of the HSB color passed in.</returns>
/// Source: http://msdn.microsoft.com/en-us/library/ms771620.aspx
public static Color ToRgb(this HsbColor hsbColor)
{
// Initialize
var rgbColor = new Color();
/* Gray (zero saturation) is a special case.We simply
* set RGB values to HSB Brightness value and exit. */
// Gray: Set RGB and return
if (hsbColor.S == 0.0)
{
rgbColor.A = (byte)(hsbColor.A * 255);
rgbColor.R = (byte)(hsbColor.B * 255);
rgbColor.G = (byte)(hsbColor.B * 255);
rgbColor.B = (byte)(hsbColor.B * 255);
return(rgbColor);
}
/* Now we process the normal case. */
var h = (hsbColor.H == 360) ? 0 : hsbColor.H / 60;
var i = (int)(Math.Truncate(h));
var f = h - i;
var p = hsbColor.B * (1.0 - hsbColor.S);
var q = hsbColor.B * (1.0 - (hsbColor.S * f));
var t = hsbColor.B * (1.0 - (hsbColor.S * (1.0 - f)));
double r, g, b;
switch (i)
{
case 0:
r = hsbColor.B;
g = t;
b = p;
break;
case 1:
r = q;
g = hsbColor.B;
b = p;
break;
case 2:
r = p;
g = hsbColor.B;
b = t;
break;
case 3:
r = p;
g = q;
b = hsbColor.B;
break;
case 4:
r = t;
g = p;
b = hsbColor.B;
break;
default:
r = hsbColor.B;
g = p;
b = q;
break;
}
// Set WPF Color object
rgbColor.A = (byte)(hsbColor.A * 255);
rgbColor.R = (byte)(r * 255);
rgbColor.G = (byte)(g * 255);
rgbColor.B = (byte)(b * 255);
// Set return value
return(rgbColor);
}
