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taybenlor/colour.js

Created October 15, 2012 23:28
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Colour Helpers in JS
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colour.js
/**
* A class to parse colour values. Updated by Ben to support colour conversions.
* @author Stoyan Stefanov <sstoo@gmail.com>
* @author Ben Taylor <taybenlor@gmail.com>
* @link http://www.phpied.com/rgb-color-parser-in-javascript/
* @license Use it if you like it
*/
function Colour(colour_string)
{
this.ok = false;
// strip any leading #
if (colour_string.charAt(0) == '#') { // remove # if any
colour_string = colour_string.substr(1,6);
}
colour_string = colour_string.replace(/ /g,'');
colour_string = colour_string.toLowerCase();
// before getting into regexps, try simple matches
// and overwrite the input
var simple_colours = {
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_colours) {
if (colour_string == key) {
colour_string = simple_colours[key];
}
}
// emd of simple type-in colours
// array of colour definition objects
var colour_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 < colour_defs.length; i++) {
var re = colour_defs[i].re;
var processor = colour_defs[i].process;
var bits = re.exec(colour_string);
if (bits) {
channels = processor(bits);
this.r = channels[0];
this.g = channels[1];
this.b = channels[2];
this.ok = true;
}
}
// 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);
// some getters
this.toRGB = function () {
return 'rgb(' + this.r + ', ' + this.g + ', ' + this.b + ')';
}
this.toHex = function () {
var r = this.r.toString(16);
var g = this.g.toString(16);
var b = this.b.toString(16);
if (r.length == 1) r = '0' + r;
if (g.length == 1) g = '0' + g;
if (b.length == 1) b = '0' + b;
return '#' + r + g + b;
}
/*
* Returns an Array of [H,S,L]
*
*/
this.toHSL = function(){
var r = this.r;
var g = this.g;
var b = this.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];
}
/*
* Returns an array of [H,S,V]
*/
this.toHSV = function(){
var r = this.r;
var g = this.g;
var b = this.b;
r = r/255, g = g/255, b = b/255;
var max = Math.max(r, g, b), min = Math.min(r, g, b);
var h, s, v = max;
var d = max - min;
s = max == 0 ? 0 : d / max;
if(max == min){
h = 0; // achromatic
}else{
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, v];
}
/*
* Returns an array of [X,Y,Z] colour values
*/
this.toXYZ = function(){
var R = ( this.r / 255 ); //R from 0 to 255
var G = ( this.g / 255 ) //G from 0 to 255
var B = ( this.b / 255 ) //B from 0 to 255
if ( R > 0.04045 ){
R = Math.pow(( ( R + 0.055 ) / 1.055 ), 2.4);
}
else{
R = R / 12.92;
}
if ( G > 0.04045 ){
G = Math.pow((( G + 0.055 ) / 1.055 ), 2.4);
}
else{
G = G / 12.92;
}
if ( B > 0.04045 ){
B = Math.pow((( B + 0.055 ) / 1.055 ), 2.4);
}
else{
B = B / 12.92;
}
R = R * 100;
G = G * 100;
B = B * 100;
//Observer. = 2°, Illuminant = D65
var X = R * 0.4124 + G * 0.3576 + B * 0.1805;
var Y = R * 0.2126 + G * 0.7152 + B * 0.0722;
var Z = R * 0.0193 + G * 0.1192 + B * 0.9505;
return [X,Y,Z];
}
/*
* Returns an array of [L,a,b] colour values
*
*/
this.toLAB = function(){
var XYZ = this.toXYZ();
var X = XYZ[0];
var Y = XYZ[1];
var Z = XYZ[2];
var L = 10 * Math.sqrt(Y);
var a = 17.5 * (((1.02 * X) - Y) / Math.sqrt(Y));
var b = 7 * ((Y - (0.847 * Z)) / Math.sqrt(Y));
return [L,a,b];
}
this.invertText = function(){
return !(this.toLAB()[0] > 79);
}
}
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