internal static IEnumerable <int> ColorLumaOrder(IEnumerable <Color> colors)
{
List <int> order = Enumerable
.Range(0, colors.Count())
.Select(x =>
{
Color color = colors.ElementAt(x);
XnaHSL hsl = new XnaHSL(color);
return(Tuple.Create(x, color, hsl));
})
// This actually needs to use luma instead of lightness,
// because the perceptual order is important
.OrderBy(x => GeneratedColorPalette.ValueFormula(x.Item2))
.ThenBy(x => x.Item3.Lightness)
// If colors have the same lightness,
// use the one with the least saturation
.ThenBy(x => x.Item3.Saturation)
// If colors have the same lightness,
// use the one with the most alpha
.ThenByDescending(x => x.Item2.A)
.Select(x => x.Item1)
.ToList();
return(order);
}
private void AdjustShadowAmount(Color color, GeneratedColorPalette palette, float rawAmount)
{
// The percent of the way between 0 and the BASE_VALUE
float amount = rawAmount / GeneratedColorPalette.BASE_VALUE;
// Avoid divide by 0
if (amount <= 0)
{
this.ShadowAmount = 1f;
return;
}
float darkestValue = GeneratedColorPalette.ValueFormula(palette.Darkest);
float baseValue = GeneratedColorPalette.ValueFormula(palette.BaseColor);
// Avoid divide by 0
if (baseValue - darkestValue == 0)
{
this.ShadowAmount = 0.5f;
return;
}
float colorValue = GeneratedColorPalette.ValueFormula(color);
float percent = (colorValue - darkestValue) / (baseValue - darkestValue);
if (amount < 0.5f)
{
float midPointValue = (percent / amount) / 2f;
this.ShadowAmount = midPointValue;
}
else
{
// Avoid divide by 0
if (amount >= 1f)
{
this.ShadowAmount = 0;
}
else
{
float midPointValue = MathHelper.Lerp(
1f, percent,
1 / (1 - (2f * amount - 1f)));
this.ShadowAmount = midPointValue;
}
}
}
internal void SetBlackLevel(Color darkestColor)
{
Generator.BlackLevel = GeneratedColorPalette.ValueFormula(darkestColor);
}
