color.js

Color = {
	_rgba: function(r, g, b, a) {
		return { r: r, g: g, b: b, a: a, toString: function() { return "rgba(" + r +", " + g + ", " + b + ", " + a + ")"; } };
	},

	_hsl: function(h, s, l) {
		return { h: h, s: s, l: l, toString: function() { return "hsl(" + h +", " + s*100 + "%, " + l*100 + "%)"; } };
	},

	_hex2Rgba: function(hex) {
		var num = parseInt(hex.substring(1), 16);
		return this._rgba(num >> 16, num >> 8 & 255, num & 255, 1);
	},

	//conversion function (modified a bit) taken from http://mjijackson.com/2008/02/
	//rgb-to-hsl-and-rgb-to-hsv-color-model-conversion-algorithms-in-javascript
	_hsl2Rgba: function(hsl) {
		var h = hsl.h/360, s = hsl.s, l = hsl.l, r, g, b;
		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;
		}
		if (s === 0) {
			r = g = b = l; // achromatic
		} else {
			var q = l < 0.5 ? l * (1 + s) : l + s - l * s;
			var p = 2 * l - q;
			r = Math.floor( (hue2rgb(p, q, h + 1/3)) * 255);
			g = Math.floor( (hue2rgb(p, q, h)) * 255);
			b = Math.floor( (hue2rgb(p, q, h - 1/3)) * 255);
		}
		return this._rgba(r, g, b, 1);
	}
}
module.exports = Color;