/// <summary>
/// Multiplies the Color's Saturation, and Luminance or Brightness by the arguments;
/// and optionally specifies the output Alpha.
/// </summary>
/// <param name="color">The color to transform.</param>
/// <param name="colorTransformMode">Transform mode.</param>
/// <param name="saturationTransform">The transformation multiplier.</param>
/// <param name="brightnessTransform">The transformation multiplier.</param>
/// <param name="outputAlpha">Can optionally specify the Alpha to directly
/// set on the output. If null, then the input <paramref name="color"/>
/// Alpha is used.</param>
/// <returns>RGB Color.</returns>
public static Color TransformSaturationAndValue(
Color color,
ColorTransformMode colorTransformMode,
double saturationTransform,
double brightnessTransform,
byte?outputAlpha = null)
{
double[] hsl = colorTransformMode == ColorTransformMode.Hsl
? SimpleColorTransforms.RgbToHsl(color)
: SimpleColorTransforms.RgbToHsb(color);
if ((SystemMath.Abs(hsl[1]) < SimpleColorTransforms.tolerance) &&
(saturationTransform > 1D))
{
hsl[1] = saturationTransform - 1D;
}
else
{
hsl[1] *= saturationTransform;
}
if ((SystemMath.Abs(hsl[2]) < SimpleColorTransforms.tolerance) &&
(brightnessTransform > 1D))
{
hsl[2] = brightnessTransform - 1D;
}
else
{
hsl[2] *= brightnessTransform;
}
return(colorTransformMode == ColorTransformMode.Hsl
? SimpleColorTransforms.HslToRgb(hsl[0], hsl[1], hsl[2], outputAlpha ?? color.A)
: SimpleColorTransforms.HsbToRgb(hsl[0], hsl[1], hsl[2], outputAlpha ?? color.A));
}
/// <summary>
/// Transforms the input <paramref name="color"/> Hue by adding the specified
/// <paramref name="hueTransform"/>; which is in [-360, 360]. The given
/// transformation value is added to the current hue (in [0, 360]); and
/// the output will be rotated to within [0, 360] (does not raise exceptions).
/// </summary>
/// <param name="color">The color to transform.</param>
/// <param name="hueTransform">The transformation to apply to this
/// <paramref name="color"/> hue: [-360, 360].</param>
/// <param name="outputAlpha">Can optionally specify the Alpha to directly
/// set on the output. If null, then the input <paramref name="color"/>
/// Alpha is used.</param>
/// <returns>RGB Color.</returns>
public static Color TransformHue(Color color, double hueTransform, byte?outputAlpha = null)
{
double[] hsl = SimpleColorTransforms.RgbToHsl(color);
hueTransform = SystemMath.Max(-360D, SystemMath.Min(360D, hueTransform));
hsl[0] += hueTransform;
if (hsl[0] > 360D)
{
hsl[0] -= 360D;
}
else if (hsl[0] < 0D)
{
hsl[0] += 360D;
}
return(SimpleColorTransforms.HslToRgb(hsl[0], hsl[1], hsl[2], outputAlpha ?? color.A));
}
