public HSVColor(HSVColor hsv, float a)
{
_h = hsv.H;
_s = hsv.S;
_v = hsv.V;
_a = a;
}
public static HSVColor ToHSVColor(Color rgb)
{
HSVColor hsv = new HSVColor();
ToHSVColor(rgb, out hsv);
return hsv;
}
public static Color ToRGBColor(HSVColor hsv)
{
//Algo explained here:
//http://en.wikipedia.org/wiki/HSL_and_HSV#Conversion_from_RGB_to_HSL_overview
float H = hsv.H * 360;
int mode = (int)Math.Floor(H / 60) % 6;
float f = (H / 60) - (float)Math.Floor(H / 60);
float p = hsv.V * (1 - hsv.S);
float q = hsv.V * (1 - f * hsv.S);
float t = hsv.V * (1 - (1 - f) * hsv.S);
switch (mode)
{
case 0:
return new Color(hsv.V, t, p, hsv.A);
case 1:
return new Color(q, hsv.V, p, hsv.A);
case 2:
return new Color(p, hsv.V, t, hsv.A);
case 3:
return new Color(p, q, hsv.V, hsv.A);
case 4:
return new Color(t, p, hsv.V, hsv.A);
case 5:
return new Color(hsv.V, p, q, hsv.A);
default:
return Color.White;
}
}
public static void ToHSVColor(Color rgb, out HSVColor hsv)
{
float H, S, V;
float R, G, B, A;
//convert to 0..1 values
R = rgb.R / 256f;
G = rgb.G / 256f;
B = rgb.B / 256f;
A = rgb.A / 256f;
hsv = White;
hsv._a = A;
float min, max;
min = max = R;
max = Math.Max(G, max);
max = Math.Max(B, max);
min = Math.Min(G, min);
min = Math.Min(B, min);
//Compute hue
if (max == min) H = 0;
else if (max == R)
{
H = (60 * ((G - B) / (max - min)) + 360);
while (H >= 360) H -= 360; //wrap value to 360
}
else if (max == G)
{
H = (60 * ((B - R) / (max - min)) + 120);
}
else //max == B
{
H = (60 * ((R - G) / (max - min)) + 240);
}
H = H / 360; //convert from degrees to 0..1 value
//compute saturation
if (max == 0)
S = 0;
else
S = 1 - min / max;
//compute value
V = max;
hsv._h = H;
hsv._s = S;
hsv._v = V;
}
