/// <summary>
/// Converts a color described in terms of alpha, red, green and blue channels (RGB) to
/// its equivalent HLS Color.
/// </summary>
/// <param name="rgbColor">The RGB color to convert.</param>
/// <returns>An equivalent HLS Color.</returns>
public static HlsColor FromRgb(Color rgbColor)
{
var hlsColor = new HlsColor();
var red = rgbColor.R / 255.0;
var green = rgbColor.G / 255.0;
var blue = rgbColor.B / 255.0;
var alpha = rgbColor.A / 255.0;
var minVal = Math.Min(red, Math.Min(green, blue));
var maxVal = Math.Max(red, Math.Max(green, blue));
var delta = maxVal - minVal;
if (maxVal == minVal)
{
hlsColor.H = 0.0;
hlsColor.S = 0.0;
hlsColor.L = maxVal;
return hlsColor;
}
hlsColor.L = (minVal + maxVal) / 2.0;
hlsColor.S = delta / ((hlsColor.L < 0.5) ? (maxVal + minVal) : (2.0 - maxVal - minVal));
if (red == maxVal) hlsColor.H = (green - blue) / delta;
if (green == maxVal) hlsColor.H = 2.0 + ((blue - red) / delta);
if (blue == maxVal) hlsColor.H = 4.0 + ((red - green) / delta);
hlsColor.H *= 60;
if (hlsColor.H < 0) hlsColor.H += 360;
hlsColor.A = alpha;
return hlsColor;
}
/// <summary>
/// Converts a color described in terms of alpha, red, green and blue channels (RGB) to
/// its equivalent HLS Color.
/// </summary>
/// <param name="rgbColor">The RGB color to convert.</param>
/// <returns>An equivalent HLS Color.</returns>
public static HlsColor FromRgb(Color rgbColor)
{
var hlsColor = new HlsColor();
var red = rgbColor.R / 255.0;
var green = rgbColor.G / 255.0;
var blue = rgbColor.B / 255.0;
var alpha = rgbColor.A / 255.0;
var minVal = Math.Min(red, Math.Min(green, blue));
var maxVal = Math.Max(red, Math.Max(green, blue));
var delta = maxVal - minVal;
if (maxVal == minVal)
{
hlsColor.H = 0.0;
hlsColor.S = 0.0;
hlsColor.L = maxVal;
return(hlsColor);
}
hlsColor.L = (minVal + maxVal) / 2.0;
hlsColor.S = delta / ((hlsColor.L < 0.5) ? (maxVal + minVal) : (2.0 - maxVal - minVal));
if (red == maxVal)
{
hlsColor.H = (green - blue) / delta;
}
if (green == maxVal)
{
hlsColor.H = 2.0 + ((blue - red) / delta);
}
if (blue == maxVal)
{
hlsColor.H = 4.0 + ((red - green) / delta);
}
hlsColor.H *= 60;
if (hlsColor.H < 0)
{
hlsColor.H += 360;
}
hlsColor.A = alpha;
return(hlsColor);
}
/// <summary>
/// Converts the color of the supplied brush changing its luminosity by the given factor.
/// </summary>
/// <param name="value">The value that is produced by the binding target.</param>
/// <param name="targetType">The type to convert to.</param>
/// <param name="parameter">The factor used to adjust the luminosity (0..1).</param>
/// <param name="culture">The culture to use in the converter (unused).</param>
/// <returns>A converted value.</returns>
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
#endif
{
if (value == null)
{
return(null);
}
if (parameter == null)
{
return(null);
}
var factor = double.Parse(parameter.ToString(), CultureInfo.InvariantCulture);
if (value is SolidColorBrush)
{
var color = ((SolidColorBrush)value).Color;
var hlsColor = HlsColor.FromRgb(color);
hlsColor.L *= factor;
return(new SolidColorBrush(hlsColor.ToRgb()));
}
else if (value is LinearGradientBrush)
{
var gradientStops = new GradientStopCollection();
foreach (var stop in ((LinearGradientBrush)value).GradientStops)
{
var hlsColor = HlsColor.FromRgb(stop.Color);
hlsColor.L *= factor;
gradientStops.Add(new GradientStop()
{
Color = hlsColor.ToRgb(), Offset = stop.Offset
});
}
var brush = new LinearGradientBrush(gradientStops, 0.0);
return(brush);
}
return(value);
}
