/// <summary>
/// Get a color between 2 color (ie gradiant step)
/// </summary>
/// <param name="s">Start Color </param>
/// <param name="e">End Color</param>
/// <param name="clamp">Intyerpolation factor : clamp [0,1]</param>
/// <param name="useHSB">Use USB convertion to compute interpolation</param>
/// <returns></returns>
public static Color GetStepColor(this Color s, Color e, double clamp, bool useHSB)
{
double t = Math.Min(Math.Max(clamp, 0), 1);
if (useHSB)
{
ColorHSB sHSB = ColorHSB.FromRGB(s);
ColorHSB eHSB = ColorHSB.FromRGB(e);
double dH = sHSB.Hue - eHSB.Hue;
double dS = sHSB.Saturation - eHSB.Saturation;
double dB = sHSB.Brightness - eHSB.Brightness;
ColorHSB mHSB = new ColorHSB();
mHSB.Hue = sHSB.Hue - t * dH;
mHSB.Saturation = sHSB.Saturation - t * dS;
mHSB.Brightness = sHSB.Brightness - t * dB;
Color ret = mHSB.ToColor();
return(ret);
}
else
{
double dR = s.R - e.R;
double dG = s.G - e.G;
double dB = s.B - e.B;
double r = s.R - t * dR;
double g = s.G - t * dG;
double b = s.B - t * dB;
Color ret = Color.FromArgb((int)r, (int)g, (int)b);
return(ret);
}
}
/// <summary>
/// Modifies an existing Hue level
/// </summary>
/// <remarks>
/// To reduce Hue use a number smaller than 1. To increase Hue use a number larger tnan 1
/// </remarks>
/// <param name="c">The original colour</param>
/// <param name="Hue">The Hue delta</param>
/// <returns>An adjusted colour</returns>
public static Color ModifyHue(this Color c, double Hue)
{
ColorHSB hsb = ColorHSB.FromRGB(c);
hsb.Hue *= Hue;
return(hsb.ToColor());
}
/// <summary>
/// Modifies an existing Saturation level
/// </summary>
/// <remarks>
/// To reduce Saturation use a number smaller than 1. To increase Saturation use a number larger tnan 1
/// </remarks>
/// <param name="c">The original colour</param>
/// <param name="Saturation">The saturation delta</param>
/// <returns>An adjusted colour</returns>
public static Color ModifySaturation(this Color c, double Saturation)
{
ColorHSB hsb = ColorHSB.FromRGB(c);
hsb.Saturation *= Saturation;
return(hsb.ToColor());
}
/// <summary>
/// Modifies an existing brightness level
/// </summary>
/// <param name="c">The original colour</param>
/// <param name="brightness">The luminance delta</param>
/// <returns>An adjusted colour</returns>
public static Color ModifyBrightness(this Color c, double brightness)
{
ColorHSB hsb = ColorHSB.FromRGB(c);
hsb.Brightness *= (1 + brightness);
return(hsb.ToColor());
}
/// <summary>
/// Sets the absolute brightness of a colour
/// </summary>
/// <param name="c">Original colour</param>
/// <param name="brightness">The luminance level to impose</param>
/// <returns>an adjusted colour</returns>
public static Color SetBrightness(this Color c, double brightness)
{
ColorHSB hsb = ColorHSB.FromRGB(c);
hsb.Brightness = brightness;
return(hsb.ToColor());
}
/// <summary>
/// Converts RGB to ColorHSB
/// </summary>
/// <remarks>Takes advantage of whats already built in to .NET by using the Color.GetHue, Color.GetSaturation and Color.GetBrightness methods</remarks>
/// <param name="c">A Color to convert</param>
/// <returns>An ColorHSB value</returns>
internal static ColorHSB FromRGB(Color c)
{
ColorHSB hsb = new ColorHSB();
hsb.Hue = c.GetHue() / 360.0; // we store hue as 0-1 as opposed to 0-360
hsb.Brightness = c.GetBrightness();
hsb.Saturation = c.GetSaturation();
return(hsb);
}
