/*
Script: Fx.Transitions.js
	Cool transitions, to be used with all the effects.

Author:
	Robert Penner, <http://www.robertpenner.com/easing/>, modified to be used with mootools.

License:
	Easing Equations v1.5, (c) 2003 Robert Penner, all rights reserved. Open Source BSD License.
*/

/*
Class: Fx.Transitions
	A collection of tweaning transitions for use with the <Fx.Base> classes.
*/

Fx.Transitions = {

	/* Property: linear */
	linear: function(t, b, c, d){
		return c*t/d + b;
	},

	/* Property: quadIn */
	quadIn: function(t, b, c, d){
		return c*(t/=d)*t + b;
	},

	/* Property: quatOut */
	quadOut: function(t, b, c, d){
		return -c *(t/=d)*(t-2) + b;
	},

	/* Property: quadInOut */
	quadInOut: function(t, b, c, d){
		if ((t/=d/2) < 1) return c/2*t*t + b;
		return -c/2 * ((--t)*(t-2) - 1) + b;
	},

	/* Property: cubicIn */
	cubicIn: function(t, b, c, d){
		return c*(t/=d)*t*t + b;
	},

	/* Property: cubicOut */
	cubicOut: function(t, b, c, d){
		return c*((t=t/d-1)*t*t + 1) + b;
	},

	/* Property: cubicInOut */
	cubicInOut: function(t, b, c, d){
		if ((t/=d/2) < 1) return c/2*t*t*t + b;
		return c/2*((t-=2)*t*t + 2) + b;
	},

	/* Property: quartIn */
	quartIn: function(t, b, c, d){
		return c*(t/=d)*t*t*t + b;
	},

	/* Property: quartOut */
	quartOut: function(t, b, c, d){
		return -c * ((t=t/d-1)*t*t*t - 1) + b;
	},

	/* Property: quartInOut */
	quartInOut: function(t, b, c, d){
		if ((t/=d/2) < 1) return c/2*t*t*t*t + b;
		return -c/2 * ((t-=2)*t*t*t - 2) + b;
	},

	/* Property: quintIn */
	quintIn: function(t, b, c, d){
		return c*(t/=d)*t*t*t*t + b;
	},

	/* Property: quintOut */
	quintOut: function(t, b, c, d){
		return c*((t=t/d-1)*t*t*t*t + 1) + b;
	},

	/* Property: quintInOut */
	quintInOut: function(t, b, c, d){
		if ((t/=d/2) < 1) return c/2*t*t*t*t*t + b;
		return c/2*((t-=2)*t*t*t*t + 2) + b;
	},

	/* Property: sineIn */
	sineIn: function(t, b, c, d){
		return -c * Math.cos(t/d * (Math.PI/2)) + c + b;
	},

	/* Property: sineOut */
	sineOut: function(t, b, c, d){
		return c * Math.sin(t/d * (Math.PI/2)) + b;
	},

	/* Property: sineInOut */
	sineInOut: function(t, b, c, d){
		return -c/2 * (Math.cos(Math.PI*t/d) - 1) + b;
	},

	/* Property: expoIn */
	expoIn: function(t, b, c, d){
		return (t==0) ? b : c * Math.pow(2, 10 * (t/d - 1)) + b;
	},

	/* Property: expoOut */
	expoOut: function(t, b, c, d){
		return (t==d) ? b+c : c * (-Math.pow(2, -10 * t/d) + 1) + b;
	},

	/* Property: expoInOut */
	expoInOut: function(t, b, c, d){
		if (t==0) return b;
		if (t==d) return b+c;
		if ((t/=d/2) < 1) return c/2 * Math.pow(2, 10 * (t - 1)) + b;
		return c/2 * (-Math.pow(2, -10 * --t) + 2) + b;
	},

	/* Property: circIn */
	circIn: function(t, b, c, d){
		return -c * (Math.sqrt(1 - (t/=d)*t) - 1) + b;
	},

	/* Property: circOut */
	circOut: function(t, b, c, d){
		return c * Math.sqrt(1 - (t=t/d-1)*t) + b;
	},

	/* Property: circInOut */
	circInOut: function(t, b, c, d){
		if ((t/=d/2) < 1) return -c/2 * (Math.sqrt(1 - t*t) - 1) + b;
		return c/2 * (Math.sqrt(1 - (t-=2)*t) + 1) + b;
	},

	/* Property: elasticIn */
	elasticIn: function(t, b, c, d, a, p){
		if (t==0) return b; if ((t/=d)==1) return b+c; if (!p) p=d*.3; if (!a) a = 1;
		if (a < Math.abs(c)){ a=c; var s=p/4; }
		else var s = p/(2*Math.PI) * Math.asin(c/a);
		return -(a*Math.pow(2,10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )) + b;
	},

	/* Property: elasticOut */
	elasticOut: function(t, b, c, d, a, p){
		if (t==0) return b; if ((t/=d)==1) return b+c; if (!p) p=d*.3; if (!a) a = 1;
		if (a < Math.abs(c)){ a=c; var s=p/4; }
		else var s = p/(2*Math.PI) * Math.asin(c/a);
		return a*Math.pow(2,-10*t) * Math.sin( (t*d-s)*(2*Math.PI)/p ) + c + b;
	},

	/* Property: elasticInOut */
	elasticInOut: function(t, b, c, d, a, p){
		if (t==0) return b; if ((t/=d/2)==2) return b+c; if (!p) p=d*(.3*1.5); if (!a) a = 1;
		if (a < Math.abs(c)){ a=c; var s=p/4; }
		else var s = p/(2*Math.PI) * Math.asin(c/a);
		if (t < 1) return -.5*(a*Math.pow(2,10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )) + b;
		return a*Math.pow(2,-10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )*.5 + c + b;
	},

	/* Property: backIn */
	backIn: function(t, b, c, d, s){
		if (!s) s = 1.70158;
		return c*(t/=d)*t*((s+1)*t - s) + b;
	},

	/* Property: backOut */
	backOut: function(t, b, c, d, s){
		if (!s) s = 1.70158;
		return c*((t=t/d-1)*t*((s+1)*t + s) + 1) + b;
	},

	/* Property: backInOut */
	backInOut: function(t, b, c, d, s){
		if (!s) s = 1.70158;
		if ((t/=d/2) < 1) return c/2*(t*t*(((s*=(1.525))+1)*t - s)) + b;
		return c/2*((t-=2)*t*(((s*=(1.525))+1)*t + s) + 2) + b;
	},

	/* Property: bounceIn */
	bounceIn: function(t, b, c, d){
		return c - Fx.Transitions.bounceOut (d-t, 0, c, d) + b;
	},

	/* Property: bounceOut */
	bounceOut: function(t, b, c, d){
		if ((t/=d) < (1/2.75)){
			return c*(7.5625*t*t) + b;
		} else if (t < (2/2.75)){
			return c*(7.5625*(t-=(1.5/2.75))*t + .75) + b;
		} else if (t < (2.5/2.75)){
			return c*(7.5625*(t-=(2.25/2.75))*t + .9375) + b;
		} else {
			return c*(7.5625*(t-=(2.625/2.75))*t + .984375) + b;
		}
	},

	/* Property: bounceInOut */
	bounceInOut: function(t, b, c, d){
		if (t < d/2) return Fx.Transitions.bounceIn(t*2, 0, c, d) * .5 + b;
		return Fx.Transitions.bounceOut(t*2-d, 0, c, d) * .5 + c*.5 + b;
	}

};