private static void GetShadow(
XnaHSL baseHSL,
PaletteGenerator generator,
PaletteParameters parameters,
out XnaHSL shadow,
out XnaHSL darkest)
{
XnaHSL blackHSL = new XnaHSL(
baseHSL.Hue,
baseHSL.Saturation * generator.ShadowAmount,
generator.BlackLevel,
baseHSL.Alpha);
// If the base color is sufficiently bright, lighten the darker shades
float lightnessRatio = (baseHSL.Lightness - 0.5f) * 2f;
if (lightnessRatio > 0)
{
blackHSL = blackHSL.SetSaturation(blackHSL.Saturation * (1f - lightnessRatio * 0.95f));
float blackLuma = Color_Util.GetLuma(blackHSL.GetColor());
// Increase the lightness by more if it's a color with a low
// luma to lightness ratio
float lumaRatio = 1f;
if (blackLuma > 0)
{
lumaRatio = blackHSL.Lightness / blackLuma;
}
blackHSL = blackHSL.SetLightness(
MathHelper.Lerp(blackHSL.Lightness,
MathHelper.Lerp(blackHSL.Lightness, 1f, 0.25f),
lightnessRatio * lumaRatio));
}
// Tint black and shadow blue
blackHSL = blackHSL.LerpHue(240, parameters.BlueShadow);
blackHSL = blackHSL.SetSaturation(MathHelper.Lerp(blackHSL.Saturation, 1f, parameters.BlueShadow / 4f));
XnaHSL shadowHSL = XnaHSL.Lerp(blackHSL, baseHSL, generator.ShadowAmount);
shadowHSL = shadowHSL.SetSaturation(MathHelper.Lerp(blackHSL.Saturation, baseHSL.Saturation, 0.5f));
shadowHSL = shadowHSL.SetHue(blackHSL.Hue);
shadowHSL = shadowHSL.LerpHue(baseHSL.Hue, 0.25f);
shadow = shadowHSL;
darkest = blackHSL;
}
public void LuminanceSort()
{
var ordered_colors = Palette
.Select(x => new Tuple <PaletteEntry, float>(
x, Color_Util.GetLuma(x.Color)))
// Put transparent colors last
.OrderBy(x => x.Item1.Value.A == 0 ? 1 : -1)
// Sort by luma
.ThenByDescending(x => x.Item2)
.Select(x => x.Item1)
.ToList();
// Reverse if it was already sorted
if (Enumerable.Range(0, Palette.Count)
.All(x => Palette.ElementAt(x) == ordered_colors.ElementAt(x)))
{
ordered_colors = ordered_colors
.Reverse <PaletteEntry>()
.OrderBy(x => x.Value.A == 0 ? 1 : -1)
.ToList();
}
Palette = ordered_colors.ToList();
}
public static float ValueFormula(Color color)
{
return(Color_Util.GetLuma(color));
}