// Given H,S,L in range of 0-1 // Returns a Color (RGB struct) in range of 0-255 /// <summary> /// HSL to RGB conversion. /// </summary> /// <param name="h">The h.</param> /// <param name="sl">The sl.</param> /// <param name="l">The l.</param> /// <returns></returns> public static ColorRGB HSL2RGB(double h, double sl, double l) { double v; double r, g, b; r = l; // default to gray g = l; b = l; v = (l <= 0.5) ? (l * (1.0 + sl)) : (l + sl - l * sl); if(v > 0) { double m; double sv; int sextant; double fract, vsf, mid1, mid2; m = l + l - v; sv = (v - m) / v; h *= 6.0; sextant = (int) h; fract = h - sextant; vsf = v * sv * fract; mid1 = m + vsf; mid2 = v - vsf; switch(sextant) { case 0: r = v; g = mid1; b = m; break; case 1: r = mid2; g = v; b = m; break; case 2: r = m; g = v; b = mid1; break; case 3: r = m; g = mid2; b = v; break; case 4: r = mid1; g = m; b = v; break; case 5: r = v; g = m; b = mid2; break; } } ColorRGB rgb = new ColorRGB(); rgb.R = Convert.ToByte(r * 255.0f); rgb.G = Convert.ToByte(g * 255.0f); rgb.B = Convert.ToByte(b * 255.0f); return rgb; }
// Given a Color (RGB Struct) in range of 0-255 // Return H,S,L in range of 0-1 /// <summary> /// RGB to HSL conversion /// </summary> /// <param name="rgb">The RGB.</param> /// <param name="h">The h.</param> /// <param name="s">The s.</param> /// <param name="l">The l.</param> public static void RGB2HSL(ColorRGB rgb, out double h, out double s, out double l) { double r = rgb.R / 255.0; double g = rgb.G / 255.0; double b = rgb.B / 255.0; double v; double m; double vm; double r2, g2, b2; h = 0; // default to black s = 0; l = 0; v = Math.Max(r, g); v = Math.Max(v, b); m = Math.Min(r, g); m = Math.Min(m, b); l = (m + v) / 2.0; if(l <= 0.0) { return; } vm = v - m; s = vm; if(s > 0.0) { s /= (l <= 0.5) ? (v + m) : (2.0 - v - m); } else { return; } r2 = (v - r) / vm; g2 = (v - g) / vm; b2 = (v - b) / vm; if(r == v) { h = (g == m ? 5.0 + b2 : 1.0 - g2); } else if(g == v) { h = (b == m ? 1.0 + r2 : 3.0 - b2); } else { h = (r == m ? 3.0 + g2 : 5.0 - r2); } h /= 6.0; }
// Given H,S,L in range of 0-1 // Returns a Color (RGB struct) in range of 0-255 /// <summary> /// HSL to RGB conversion. /// </summary> /// <param name="h">The h.</param> /// <param name="sl">The sl.</param> /// <param name="l">The l.</param> /// <returns></returns> public static ColorRGB HSL2RGB(double h, double sl, double l) { double v; double r, g, b; r = l; // default to gray g = l; b = l; v = (l <= 0.5) ? (l * (1.0 + sl)) : (l + sl - l * sl); if (v > 0) { double m; double sv; int sextant; double fract, vsf, mid1, mid2; m = l + l - v; sv = (v - m) / v; h *= 6.0; sextant = (int)h; fract = h - sextant; vsf = v * sv * fract; mid1 = m + vsf; mid2 = v - vsf; switch (sextant) { case 0: r = v; g = mid1; b = m; break; case 1: r = mid2; g = v; b = m; break; case 2: r = m; g = v; b = mid1; break; case 3: r = m; g = mid2; b = v; break; case 4: r = mid1; g = m; b = v; break; case 5: r = v; g = m; b = mid2; break; } } ColorRGB rgb = new ColorRGB(); rgb.R = Convert.ToByte(r * 255.0f); rgb.G = Convert.ToByte(g * 255.0f); rgb.B = Convert.ToByte(b * 255.0f); return(rgb); }