/*

	Lost Boys 2005.
	
	De inhoud van dit bestand is in opdracht vervaardigd en eigendom van onze opdrachtgever.
	Niet hergebruiken zonder toestemming.
	Neem voor vragen contact op met Lost Boys, www.lostboys.nl.

	The contents of this file have been produced for and are the property of our client.
	Do not reuse without permission.
	Any questions? Please contact Lost Boys, www.lostboys.nl.

*/
Animator = function (startValue, endValue, f, t, r) {
	this.step  = 10;	    	//The step by which timer counts from 0 to 100
	this.rate  = 10;	    //The rate in ms at which steps are taken
	this.power = 2;         //The steepness of the animation curve
	this.type  = this.NONE; //The type of easing

	this.min = startValue;
	this.max = endValue;
	this.isReversing = false;
	this.animateFunction = f;
	this.terminateFunction = t;
	this.reversalFunction = r;

	this.precalc = new Array(100);
	for (var i=0; i <= 100; i++) this.precalc[i] = this.calculate(i);
}
Animator.prototype.NONE      = 0;
Animator.prototype.EASEIN    = 1;
Animator.prototype.EASEOUT   = 2;
Animator.prototype.EASEINOUT = 3;

Animator.prototype.setStep = function (step) {
	this.step = step;
}
Animator.prototype.setRate = function (rate) {
	this.rate = rate;
}
Animator.prototype.setPower = function (power) {
	this.power = power;
	for (var i=0; i <= 100; i++) this.precalc[i] = this.calculate(i);
}
Animator.prototype.setType = function (type) {
	this.type = type;
	for (var i=0; i <= 100; i++) this.precalc[i] = this.calculate(i);
}
Animator.prototype.setAnimateFunction = function (f) {
	this.animateFunction = f;
}
Animator.prototype.start = function () {
	if (this.interval) return;
	this.time = 0;
	this.isReversing = false;
	this.interval = setInterval(this.method(this.animate), this.rate);
}
Animator.prototype.reverse = function () {
	this.isReversing = (this.isReversing) ? false : true;
}
Animator.prototype.stop = function () {
	if (this.interval) clearInterval(this.interval);
	this.interval = null;
}
Animator.prototype.pause = function () {
	//this.paused = true;
	if (this.interval) clearInterval(this.interval);
}
Animator.prototype.resume = function () {
	//this.paused = false;
	this.interval = setInterval(this.method(this.animate), this.rate);
}
Animator.prototype.isAnimating = function () {
	return Boolean(this.interval);
}
Animator.prototype.animate = function () {
	if (this.time >= 0 && this.time <= 100) {
		this.animateFunction(this.precalc[this.time]);
		this.time = (this.isReversing) ? this.time - this.step : this.time + this.step;
	} else {
		clearInterval(this.interval);
		this.interval = null;
		if (!this.isReversing && this.terminateFunction) this.terminateFunction();
		if (this.isReversing && this.reversalFunction) this.reversalFunction();
	}
}
Animator.prototype.calculate = function (t) {
	t = t/100;
	var factor;
	switch (this.type) {
		case this.NONE      : factor = this.easeNone(t);break;
		case this.EASEIN    : factor = this.easeIn(t);break;
		case this.EASEOUT   : factor = this.easeOut(t);break;
		case this.EASEINOUT : factor = this.easeInOut(t);break;
	}
	return parseInt(this.min + factor*(this.max-this.min));
}
Animator.prototype.easeNone = function (t) {
	return t;
}
Animator.prototype.easeIn = function (t) {
	return Math.pow(t,this.power);
}
Animator.prototype.easeOut = function (t) {
	return 1-this.easeIn(1-t);
}
Animator.prototype.easeInOut = function (t) {
	if (t < 0.5) return this.easeIn(t*2)/2;
	return 0.5+this.easeOut((t-0.5)*2)/2;
}