art/core/color.js

Cross-browser Vector Graphics

var colors = {
	maroon: '#800000', red: '#ff0000', orange: '#ffA500', yellow: '#ffff00', olive: '#808000',
	purple: '#800080', fuchsia: "#ff00ff", white: '#ffffff', lime: '#00ff00', green: '#008000',
	navy: '#000080', blue: '#0000ff', aqua: '#00ffff', teal: '#008080',
	black: '#000000', silver: '#c0c0c0', gray: '#808080'
};

var map = function(array, fn){
	var results = [];
	for (var i = 0, l = array.length; i < l; i++)
		results[i] = fn(array[i], i);
	return results;
};

var Color = function(color, type){
	
	if (color.isColor){
		
		this.red = color.red;
		this.green = color.green;
		this.blue = color.blue;
		this.alpha = color.alpha;

	} else {
		
		var namedColor = colors[color];
		if (namedColor){
			color = namedColor;
			type = 'hex';
		}

		switch (typeof color){
			case 'string': if (!type) type = (type = color.match(/^rgb|^hsb|^hsl/)) ? type[0] : 'hex'; break;
			case 'object': type = type || 'rgb'; color = color.toString(); break;
			case 'number': type = 'hex'; color = color.toString(16); break;
		}

		color = Color['parse' + type.toUpperCase()](color);
		this.red = color[0];
		this.green = color[1];
		this.blue = color[2];
		this.alpha = color[3];
	}
	
	this.isColor = true;

};

var limit = function(number, min, max){
	return Math.min(max, Math.max(min, number));
};

var listMatch = /([-.\d]+\%?)\s*,\s*([-.\d]+\%?)\s*,\s*([-.\d]+\%?)\s*,?\s*([-.\d]*\%?)/;
var hexMatch = /^#?([a-f0-9]{1,2})([a-f0-9]{1,2})([a-f0-9]{1,2})([a-f0-9]{0,2})$/i;

Color.parseRGB = function(color){
	return map(color.match(listMatch).slice(1), function(bit, i){
		if (bit) bit = parseFloat(bit) * (bit[bit.length - 1] == '%' ? 2.55 : 1);
		return (i < 3) ? Math.round(((bit %= 256) < 0) ? bit + 256 : bit) : limit(((bit === '') ? 1 : Number(bit)), 0, 1);
	});
};
	
Color.parseHEX = function(color){
	if (color.length == 1) color = color + color + color;
	return map(color.match(hexMatch).slice(1), function(bit, i){
		if (i == 3) return (bit) ? parseInt(bit, 16) / 255 : 1;
		return parseInt((bit.length == 1) ? bit + bit : bit, 16);
	});
};
	
Color.parseHSB = function(color){
	var hsb = map(color.match(listMatch).slice(1), function(bit, i){
		if (bit) bit = parseFloat(bit);
		if (i === 0) return Math.round(((bit %= 360) < 0) ? (bit + 360) : bit);
		else if (i < 3) return limit(Math.round(bit), 0, 100);
		else return limit(((bit === '') ? 1 : Number(bit)), 0, 1);
	});
	
	var a = hsb[3];
	var br = Math.round(hsb[2] / 100 * 255);
	if (hsb[1] == 0) return [br, br, br, a];
		
	var hue = hsb[0];
	var f = hue % 60;
	var p = Math.round((hsb[2] * (100 - hsb[1])) / 10000 * 255);
	var q = Math.round((hsb[2] * (6000 - hsb[1] * f)) / 600000 * 255);
	var t = Math.round((hsb[2] * (6000 - hsb[1] * (60 - f))) / 600000 * 255);

	switch (Math.floor(hue / 60)){
		case 0: return [br, t, p, a];
		case 1: return [q, br, p, a];
		case 2: return [p, br, t, a];
		case 3: return [p, q, br, a];
		case 4: return [t, p, br, a];
		default: return [br, p, q, a];
	}
};

Color.parseHSL = function(color){
	var hsb = map(color.match(listMatch).slice(1), function(bit, i){
		if (bit) bit = parseFloat(bit);
		if (i === 0) return Math.round(((bit %= 360) < 0) ? (bit + 360) : bit);
		else if (i < 3) return limit(Math.round(bit), 0, 100);
		else return limit(((bit === '') ? 1 : Number(bit)), 0, 1);
	});

	var h = hsb[0] / 60;
	var s = hsb[1] / 100;
	var l = hsb[2] / 100;
	var a = hsb[3];
	
	var c = (1 - Math.abs(2 * l - 1)) * s;
	var x = c * (1 - Math.abs(h % 2 - 1));
	var m = l - c / 2;
	
	var p = Math.round((c + m) * 255);
	var q = Math.round((x + m) * 255);
	var t = Math.round((m) * 255);

	switch (Math.floor(h)){
		case 0: return [p, q, t, a];
		case 1: return [q, p, t, a];
		case 2: return [t, p, q, a];
		case 3: return [t, q, p, a];
		case 4: return [q, t, p, a];
		default: return [p, t, q, a];
	}
};

var toString = function(type, array){
	if (array[3] != 1) type += 'a';
	else array.pop();
	return type + '(' + array.join(', ') + ')';
};

Color.prototype = {

	toHSB: function(array){
		var red = this.red, green = this.green, blue = this.blue, alpha = this.alpha;

		var max = Math.max(red, green, blue), min = Math.min(red, green, blue), delta = max - min;
		var hue = 0, saturation = (delta != 0) ? delta / max : 0, brightness = max / 255;
		if (saturation){
			var rr = (max - red) / delta, gr = (max - green) / delta, br = (max - blue) / delta;
			hue = (red == max) ? br - gr : (green == max) ? 2 + rr - br : 4 + gr - rr;
			if ((hue /= 6) < 0) hue++;
		}

		var hsb = [Math.round(hue * 360), Math.round(saturation * 100), Math.round(brightness * 100), alpha];

		return (array) ? hsb : toString('hsb', hsb);
	},

	toHSL: function(array){
		var red = this.red, green = this.green, blue = this.blue, alpha = this.alpha;

		var max = Math.max(red, green, blue), min = Math.min(red, green, blue), delta = max - min;
		var hue = 0, saturation = (delta != 0) ? delta / (255 - Math.abs((max + min) - 255)) : 0, lightness = (max + min) / 512;
		if (saturation){
			var rr = (max - red) / delta, gr = (max - green) / delta, br = (max - blue) / delta;
			hue = (red == max) ? br - gr : (green == max) ? 2 + rr - br : 4 + gr - rr;
			if ((hue /= 6) < 0) hue++;
		}

		var hsl = [Math.round(hue * 360), Math.round(saturation * 100), Math.round(lightness * 100), alpha];

		return (array) ? hsl : toString('hsl', hsl);
	},

	toHEX: function(array){

		var a = this.alpha;
		var alpha = ((a = Math.round((a * 255)).toString(16)).length == 1) ? a + a : a;
		
		var hex = map([this.red, this.green, this.blue], function(bit){
			bit = bit.toString(16);
			return (bit.length == 1) ? '0' + bit : bit;
		});
		
		return (array) ? hex.concat(alpha) : '#' + hex.join('') + ((alpha == 'ff') ? '' : alpha);
	},
	
	toRGB: function(array){
		var rgb = [this.red, this.green, this.blue, this.alpha];
		return (array) ? rgb : toString('rgb', rgb);
	}

};

Color.prototype.toString = Color.prototype.toRGB;

Color.hex = function(hex){
	return new Color(hex, 'hex');
};

if (this.hex == null) this.hex = Color.hex;

Color.hsb = function(h, s, b, a){
	return new Color([h || 0, s || 0, b || 0, (a == null) ? 1 : a], 'hsb');
};

if (this.hsb == null) this.hsb = Color.hsb;

Color.hsl = function(h, s, l, a){
	return new Color([h || 0, s || 0, l || 0, (a == null) ? 1 : a], 'hsl');
};

if (this.hsl == null) this.hsl = Color.hsl;

Color.rgb = function(r, g, b, a){
	return new Color([r || 0, g || 0, b || 0, (a == null) ? 1 : a], 'rgb');
};

if (this.rgb == null) this.rgb = Color.rgb;

Color.detach = function(color){
	color = new Color(color);
	return [Color.rgb(color.red, color.green, color.blue).toString(), color.alpha];
};

module.exports = Color;