Convert an RGB color value to HSL

rgbToHsl.js

/**
 * Convert an RGB color value to HSL
 *
 * @param   Number  r  The red color value (0-255)
 * @param   Number  g  The green color value (0-255)
 * @param   Number  b  The blue color value (0-255)
 * @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),
        h, s,
        l = (max + min) / 2 ; // Calculate l
    if(max == min) {
        h = s = 0; // Grayscale
    } else {
        var d = max - min;
        s = l < 0.5 ? d / (max + min) : d / (2.0 - d); // Calculate s
        // Calculate h
        switch(max) {
            case r: h = (g - b) / d; break;
            case g: h = 2.0 + (b - r) / d; break;
            case b: h = 4.0 + (r - g) / d; break;
        }
    }
    h = Math.round(h * 60);
    s = Math.round(s * 100);
    l = Math.round(l * 100);
    if(h<0) h += 360;

    return [h, s, l];
}