color.js

/**
 * A class to parse color values
 * @author Stoyan Stefanov <sstoo@gmail.com>
 * @link   http://www.phpied.com/rgb-color-parser-in-javascript/
 * @license Use it if you like it
 */
function Color(colorString) {
    this.init(colorString);
}
Color.prototype = {
    init: function(colorString) {
        if ( colorString == undefined ) {
            colorString = 'black';
        }

        // strip any leading #
        if (colorString.charAt(0) == '#') { // remove # if any
            colorString = colorString.substr(1,6);
        }

        colorString = colorString.replace(/ /g,'');
        colorString = colorString.toLowerCase();

        // before getting into regexps, try simple matches
        // and overwrite the input
        var simple_colors = {
            aliceblue: 'f0f8ff',
            antiquewhite: 'faebd7',
            aqua: '00ffff',
            aquamarine: '7fffd4',
            azure: 'f0ffff',
            beige: 'f5f5dc',
            bisque: 'ffe4c4',
            black: '000000',
            blanchedalmond: 'ffebcd',
            blue: '0000ff',
            blueviolet: '8a2be2',
            brown: 'a52a2a',
            burlywood: 'deb887',
            cadetblue: '5f9ea0',
            chartreuse: '7fff00',
            chocolate: 'd2691e',
            coral: 'ff7f50',
            cornflowerblue: '6495ed',
            cornsilk: 'fff8dc',
            crimson: 'dc143c',
            cyan: '00ffff',
            darkblue: '00008b',
            darkcyan: '008b8b',
            darkgoldenrod: 'b8860b',
            darkgray: 'a9a9a9',
            darkgreen: '006400',
            darkkhaki: 'bdb76b',
            darkmagenta: '8b008b',
            darkolivegreen: '556b2f',
            darkorange: 'ff8c00',
            darkorchid: '9932cc',
            darkred: '8b0000',
            darksalmon: 'e9967a',
            darkseagreen: '8fbc8f',
            darkslateblue: '483d8b',
            darkslategray: '2f4f4f',
            darkturquoise: '00ced1',
            darkviolet: '9400d3',
            deeppink: 'ff1493',
            deepskyblue: '00bfff',
            dimgray: '696969',
            dodgerblue: '1e90ff',
            feldspar: 'd19275',
            firebrick: 'b22222',
            floralwhite: 'fffaf0',
            forestgreen: '228b22',
            fuchsia: 'ff00ff',
            gainsboro: 'dcdcdc',
            ghostwhite: 'f8f8ff',
            gold: 'ffd700',
            goldenrod: 'daa520',
            gray: '808080',
            green: '008000',
            greenyellow: 'adff2f',
            honeydew: 'f0fff0',
            hotpink: 'ff69b4',
            indianred : 'cd5c5c',
            indigo : '4b0082',
            ivory: 'fffff0',
            khaki: 'f0e68c',
            lavender: 'e6e6fa',
            lavenderblush: 'fff0f5',
            lawngreen: '7cfc00',
            lemonchiffon: 'fffacd',
            lightblue: 'add8e6',
            lightcoral: 'f08080',
            lightcyan: 'e0ffff',
            lightgoldenrodyellow: 'fafad2',
            lightgrey: 'd3d3d3',
            lightgreen: '90ee90',
            lightpink: 'ffb6c1',
            lightsalmon: 'ffa07a',
            lightseagreen: '20b2aa',
            lightskyblue: '87cefa',
            lightslateblue: '8470ff',
            lightslategray: '778899',
            lightsteelblue: 'b0c4de',
            lightyellow: 'ffffe0',
            lime: '00ff00',
            limegreen: '32cd32',
            linen: 'faf0e6',
            magenta: 'ff00ff',
            maroon: '800000',
            mediumaquamarine: '66cdaa',
            mediumblue: '0000cd',
            mediumorchid: 'ba55d3',
            mediumpurple: '9370d8',
            mediumseagreen: '3cb371',
            mediumslateblue: '7b68ee',
            mediumspringgreen: '00fa9a',
            mediumturquoise: '48d1cc',
            mediumvioletred: 'c71585',
            midnightblue: '191970',
            mintcream: 'f5fffa',
            mistyrose: 'ffe4e1',
            moccasin: 'ffe4b5',
            navajowhite: 'ffdead',
            navy: '000080',
            oldlace: 'fdf5e6',
            olive: '808000',
            olivedrab: '6b8e23',
            orange: 'ffa500',
            orangered: 'ff4500',
            orchid: 'da70d6',
            palegoldenrod: 'eee8aa',
            palegreen: '98fb98',
            paleturquoise: 'afeeee',
            palevioletred: 'd87093',
            papayawhip: 'ffefd5',
            peachpuff: 'ffdab9',
            peru: 'cd853f',
            pink: 'ffc0cb',
            plum: 'dda0dd',
            powderblue: 'b0e0e6',
            purple: '800080',
            red: 'ff0000',
            rosybrown: 'bc8f8f',
            royalblue: '4169e1',
            saddlebrown: '8b4513',
            salmon: 'fa8072',
            sandybrown: 'f4a460',
            seagreen: '2e8b57',
            seashell: 'fff5ee',
            sienna: 'a0522d',
            silver: 'c0c0c0',
            skyblue: '87ceeb',
            slateblue: '6a5acd',
            slategray: '708090',
            snow: 'fffafa',
            springgreen: '00ff7f',
            steelblue: '4682b4',
            tan: 'd2b48c',
            teal: '008080',
            thistle: 'd8bfd8',
            tomato: 'ff6347',
            turquoise: '40e0d0',
            violet: 'ee82ee',
            violetred: 'd02090',
            wheat: 'f5deb3',
            white: 'ffffff',
            whitesmoke: 'f5f5f5',
            yellow: 'ffff00',
            yellowgreen: '9acd32'
        };
        for (var key in simple_colors) {
            if (colorString == key) {
                colorString = simple_colors[key];
            }
        }
        // emd of simple type-in colors

        // array of color definition objects
        var color_defs = [
            {
                re: /^rgb\((\d{1,3}),\s*(\d{1,3}),\s*(\d{1,3})\)$/,
                example: ['rgb(123, 234, 45)', 'rgb(255,234,245)'],
                process: function (bits){
                    return [
                        parseInt(bits[1]),
                        parseInt(bits[2]),
                        parseInt(bits[3])
                    ];
                }
            },
            {
                re: /^(\w{2})(\w{2})(\w{2})$/,
                example: ['#00ff00', '336699'],
                process: function (bits){
                    return [
                        parseInt(bits[1], 16),
                        parseInt(bits[2], 16),
                        parseInt(bits[3], 16)
                    ];
                }
            },
            {
                re: /^(\w{1})(\w{1})(\w{1})$/,
                example: ['#fb0', 'f0f'],
                process: function (bits){
                    return [
                        parseInt(bits[1] + bits[1], 16),
                        parseInt(bits[2] + bits[2], 16),
                        parseInt(bits[3] + bits[3], 16)
                    ];
                }
            }
        ];

        // search through the definitions to find a match
        for (var i = 0; i < color_defs.length; i++) {
            var re = color_defs[i].re;
            var processor = color_defs[i].process;
            var bits = re.exec(colorString);
            if (bits) {
                var channels = processor(bits);
                this.r = channels[0];
                this.g = channels[1];
                this.b = channels[2];
            }

        }

        // validate/cleanup values
        this.r = (this.r < 0 || isNaN(this.r)) ? 0 : ((this.r > 255) ? 255 : this.r);
        this.g = (this.g < 0 || isNaN(this.g)) ? 0 : ((this.g > 255) ? 255 : this.g);
        this.b = (this.b < 0 || isNaN(this.b)) ? 0 : ((this.b > 255) ? 255 : this.b);

        // set up initial hsv
        this.setRGB(this.r, this.g, this.b);
    },
    setRGB: function(r, g, b) { // null = don't change
        var hsv = this.RGB_HSV(
            r==null ? this.r : (this.r = r),
            g==null ? this.g : (this.g = g),
            b==null ? this.b : (this.b = b)
        );

        if (hsv[0] != null) {
            this.h = hsv[0];
        }

        if (hsv[2] != 0) {
            this.s = hsv[1];
        }

        this.v = hsv[2];
    },
    setHSV: function(h, s, v) { // null = don't change
        var rgb = this.HSV_RGB(
            h==null ? this.h : (this.h=h),
            s==null ? this.s : (this.s=s),
            v==null ? this.v : (this.v=v)
        );

        this.r = rgb[0];
        this.g = rgb[1];
        this.b = rgb[2];
    },
    RGB_HSV: function(r, g, b) {
        var n = Math.min(Math.min(r, g), b);
        var v = Math.max(Math.max(r, g), b);
        var m = v - n;

        if(m == 0) {
            return [ null, 0, v ];
        }

        var h = r==n ? 3 + (b - g) / m : (g == n ? 5 + (r - b) / m : 1 + (g - r) / m);

        return [ h == 6? 0: h, m / v, v ];
    },
    HSV_RGB: function(h, s, v) {
        if (h == null) {
            return [ v, v, v ];
        }

        var i = Math.floor(h);
        var f = i % 2 ? h - i : 1 - (h - i);
        var m = v * (1 - s);
        var n = v * (1 - s * f);

        switch(i) {
            case 6:
            case 0:
                return [ v, n, m ];
            case 1:
                return [ n, v, m ];
            case 2:
                return [ m, v, n ];
            case 3:
                return [ m, n, v ];
            case 4:
                return [ n, m, v ];
            case 5:
                return [ v, m, n ];
        }
    },
    toString: function() {
        var r = Math.round(this.r).toString(16);
        var g = Math.round(this.g).toString(16);
        var b = Math.round(this.b).toString(16);

        return (
            (r.length == 1 ? '0' + r : r) +
            (g.length == 1 ? '0' + g : g) +
            (b.length == 1 ? '0' + b : b)
            ).toUpperCase();
    },
    toRGBArray: function() {
        return [this.r, this.g, this.b];
    },
    toHSVArray: function() {
        return [this.h, this.s, this.v];
    }
}