/// <summary>
/// HSVの色調整を行ってピクセルデータを返す。
/// </summary>
/// <param name="c">カラー</param>
/// <param name="hue">色差加算値(-360≦hue≦360)</param>
/// <param name="saturation">彩度加割合(-255≦saturation≦255)</param>
/// <param name="lightness">輝度加算割合(-255≦lightness≦255)</param>
/// <returns></returns>
public static Color ProcessHSLFilter(Color c, int hue, int saturation, int lightness)
{
if (((hue == 0) && (saturation == 0) && (lightness == 0)))
{
return(c); // 色変換しない。
}
ColorHSL srcHSL = ColorConverter.ConvertRGBtoHSL(c);
float h = ColorUtility.GetHueWithLimitedRange((srcHSL.Hue + hue) % 360.0f);
float s = ColorUtility.ModifyValueByPercent(srcHSL.Saturation, 0f, 1.0f, saturation / 255.0f);
float l = Math.Min(ColorUtility.ModifyValueByPercent(srcHSL.Lightness, 0f, srcHSL.Lightness * 2, lightness / 255.0f), 1.0f);
return(ColorConverter.ConvertHSLtoRGB(ColorHSL.FromHSL(h, s, l), c.A));
}
/// <summary>
/// RGBからHSLへ変換を行う。
/// </summary>
/// <param name="rgb">RGB色</param>
/// <returns>HSL色</returns>
public static ColorHSL ConvertRGBtoHSL(Color rgb)
{
int min = Math.Min(rgb.G, Math.Min(rgb.B, rgb.R));
int max = Math.Max(rgb.G, Math.Max(rgb.B, rgb.R));
float hue = GetHue(rgb, min, max);
float lightness = ((min + max) / 2.0f) / 255.0f;
float saturation;
if (min == max)
{
saturation = 0.0f;
}
else
{
saturation = (lightness < 0.5)
? (float)(max - min) / (float)(max + min)
: (float)(max - min) / (2 * 255.0f - max - min);
}
return(ColorHSL.FromHSL(hue, saturation, lightness));
}
