Color conversion scripts
Revision as of 12:43, 21 August 2007 by Sally LaSalle (talk | contribs) (Color conversion script for conversion to and from RGB to HSV)
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The following functions convert between LSL color in Red Green Blue (RGB) format and color in Hue Saturation Value (HSV) format. The functions are based on "c" algorithms from c color conversion but required some debugging and extensive re-working to fit them in to LSL. For a discussion of HSV color format please see the wikipedia entry at HSV Color
// by Sally LaSalle, code released to the public domain under GNU license. // takes an RGB color as a vector, with range <float R[0,1], float G[0,1], float B[0,1]> // returns a vector with HSV ranged from <float H[0,360], float S[0,1], float V[0,1]> // H ranges smoothly from Red=0, Yellow=60, Green=120, Cyan=180, Blue=240, Violet=300 and back to Red vector RGBtoHSV( vector rgb ) { float R = rgb.x; float G = rgb.y; float B = rgb.z; float H; float S; float V; list rgbList = [R, G, B]; // list used to get min and max float min; float max; float achromatic; // =1 if R=G=B float delta; vector hsv; // the return HSV vector min = llListStatistics(LIST_STAT_MIN, rgbList); //MIN of ( R, G, B ); max = llListStatistics(LIST_STAT_MAX, rgbList); //MAX of ( R, G, B ); if (R==G && G==B) achromatic= 1; // it is a shade of grey, white or black else achromatic= 0; V = max; // V = brightness Value form 0 to 1 delta = max - min; if( max != 0 ) S = delta / max; // S = saturation from 0 to 1 else { // R = G = B = 0 // S = 0, V = 0, H = 0 S = 0; V = 0; H = 0; hsv.x = H; hsv.y = S; hsv.z = V; return hsv; //H = S = V = 0 } if (achromatic == 1) H = 0; else if( R == max ) H = 0 + ( G - B ) / delta; // between red & yellow else if( G == max ) H = 2 + ( B - R ) / delta; // between yellow & cyan else H = 4 + ( R - G ) / delta; // between cyan & red H *= 60; // H is traditionally a figure between 0 and 360 degrees if( H < 0 ) H += 360; hsv.x = H; hsv.y = S; hsv.z = V; return hsv; }