//--
//-- RGB colour object
//--

// Construct an RGB colour object from a '#rrggbb', '#rgb' or 'rgb(n,n,n)' string or from separate r,g,b values
function RGB(r,g,b)
{
	this.r = 0;
	this.g = 0;
	this.b = 0;
	if(typeof r == "string") {
		if(r.substr(0,1) == "#") {
			if(r.length == 7) {
				this.r = parseInt(r.substr(1,2),16)/255;
				this.g = parseInt(r.substr(3,2),16)/255;
				this.b = parseInt(r.substr(5,2),16)/255;
			} else {
				this.r = parseInt(r.substr(1,1),16)/15;
				this.g = parseInt(r.substr(2,1),16)/15;
				this.b = parseInt(r.substr(3,1),16)/15;
			}
		} else {
			var rgbPattern = /rgb\s*\(\s*(\d{1,3})\s*,\s*(\d{1,3})\s*,\s*(\d{1,3})\s*\)/;
			var c = r.match(rgbPattern);
			if(c) {
				this.r = parseInt(c[1],10)/255;
				this.g = parseInt(c[2],10)/255;
				this.b = parseInt(c[3],10)/255;
			}
		}
	} else {
		this.r = r;
		this.g = g;
		this.b = b;
	}
	return this;
}

// Mixes this colour with another in a specified proportion
// c = other colour to mix
// f = 0..1 where 0 is this colour and 1 is the new colour
// Returns an RGB object
RGB.prototype.mix = function(c,f)
{
	return new RGB(this.r + (c.r-this.r) * f,this.g + (c.g-this.g) * f,this.b + (c.b-this.b) * f);
};

// Return an rgb colour as a #rrggbb format hex string
RGB.prototype.toString = function()
{
	var clamp = function(x,min,max) {
		return x < min ? min : (x > max ? max : x);
	};
	return "#" +
			("0" + Math.floor(clamp(this.r,0,1) * 255).toString(16)).right(2) +
			("0" + Math.floor(clamp(this.g,0,1) * 255).toString(16)).right(2) +
			("0" + Math.floor(clamp(this.b,0,1) * 255).toString(16)).right(2);
};