mirror of
https://github.com/codeninjasllc/codecombat.git
synced 2024-12-18 03:23:42 -05:00
72 lines
No EOL
1.9 KiB
JavaScript
72 lines
No EOL
1.9 KiB
JavaScript
// http://stackoverflow.com/questions/2353211/hsl-to-rgb-color-conversion
|
|
|
|
/**
|
|
* Converts an HSL color value to RGB. Conversion formula
|
|
* adapted from http://en.wikipedia.org/wiki/HSL_color_space.
|
|
* Assumes h, s, and l are contained in the set [0, 1] and
|
|
* returns r, g, and b in the set [0, 255].
|
|
*
|
|
* @param Number h The hue
|
|
* @param Number s The saturation
|
|
* @param Number l The lightness
|
|
* @return Array The RGB representation
|
|
*/
|
|
function hslToRgb(h, s, l){
|
|
var r, g, b;
|
|
|
|
if(s == 0){
|
|
r = g = b = l; // achromatic
|
|
}else{
|
|
function hue2rgb(p, q, t){
|
|
if(t < 0) t += 1;
|
|
if(t > 1) t -= 1;
|
|
if(t < 1/6) return p + (q - p) * 6 * t;
|
|
if(t < 1/2) return q;
|
|
if(t < 2/3) return p + (q - p) * (2/3 - t) * 6;
|
|
return p;
|
|
}
|
|
|
|
var q = l < 0.5 ? l * (1 + s) : l + s - l * s;
|
|
var p = 2 * l - q;
|
|
r = hue2rgb(p, q, h + 1/3);
|
|
g = hue2rgb(p, q, h);
|
|
b = hue2rgb(p, q, h - 1/3);
|
|
}
|
|
|
|
return [r * 255, g * 255, b * 255];
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
* Converts an RGB color value to HSL. Conversion formula
|
|
* adapted from http://en.wikipedia.org/wiki/HSL_color_space.
|
|
* Assumes r, g, and b are contained in the set [0, 255] and
|
|
* returns h, s, and l in the set [0, 1].
|
|
*
|
|
* @param Number r The red color value
|
|
* @param Number g The green color value
|
|
* @param Number b The blue color value
|
|
* @return Array The HSL representation
|
|
*/
|
|
|
|
function rgbToHsl(r, g, b){
|
|
r /= 255, g /= 255, b /= 255;
|
|
var max = Math.max(r, g, b), min = Math.min(r, g, b);
|
|
var h, s, l = (max + min) / 2;
|
|
|
|
if(max == min){
|
|
h = s = 0; // achromatic
|
|
}else{
|
|
var d = max - min;
|
|
s = l > 0.5 ? d / (2 - max - min) : d / (max + min);
|
|
switch(max){
|
|
case r: h = (g - b) / d + (g < b ? 6 : 0); break;
|
|
case g: h = (b - r) / d + 2; break;
|
|
case b: h = (r - g) / d + 4; break;
|
|
}
|
|
h /= 6;
|
|
}
|
|
|
|
return [h, s, l];
|
|
} |