package com.actiontad.gameUtils {


	/**
	 * Author: Robert Penner
	 * 
	 * Easing functions by Robert Penner.
	 *
	 * AS3 ... args are to help easily account for/incorporate the few functions that take more than 4 args.
	 * Used in com.actiontad.gameUtils.SimpleStaticTweener.
	 *
	 */

	public class RPEase {
		
		//Back
		public static function InBack (t:Number, b:Number, c:Number, d:Number, s:Number, ... args):Number {
			//if (s == undefined) s = 1.70158;
			return c*(t/=d)*t*((s+1)*t - s) + b;
		}
		public static function OutBack (t:Number, b:Number, c:Number, d:Number, s:Number, ... args):Number {
			//if (s == undefined) s = 1.70158;
			return c*((t=t/d-1)*t*((s+1)*t + s) + 1) + b;
		}
		public static function InOutBack (t:Number, b:Number, c:Number, d:Number, s:Number, ... args):Number {
			//if (s == undefined) 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;
		}
		
		//Bounce
		public static function OutBounce (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			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;
			}
		}
		public static function InBounce(t:Number, b:Number, c:Number, d:Number, ... args):Number {
			return c - OutBounce (d-t, 0, c, d) + b;
		}
		public static function InOutBounce (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			if (t < d/2) return InBounce (t*2, 0, c, d) * .5 + b;
			else return OutBounce (t*2-d, 0, c, d) * .5 + c*.5 + b;
		}
		//Circ
		public static function InCirc (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			return -c * (Math.sqrt(1 - (t/=d)*t) - 1) + b;
		}
		public static function OutCirc (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			return c * Math.sqrt(1 - (t=t/d-1)*t) + b;
		}
		public static function InOutCirc (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			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;
		}
		//Cubic
		public static function In (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			return c*(t/=d)*t*t + b;
		}
		public static function Out (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			return c*((t=t/d-1)*t*t + 1) + b;
		}
		public static function InOut (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			if ((t/=d/2) < 1) return c/2*t*t*t + b;
			return c/2*((t-=2)*t*t + 2) + b;
		}
		//Elastic
		public static function InElastic (t:Number, b:Number, c:Number, d:Number, a:Number, p:Number, ... args):Number {
			if (t==0) return b;  if ((t/=d)==1) return b+c;  if (!p) p=d*.3;
			if (!a || a < Math.abs(c)) { a=c; var s:Number =p/4; }
			else 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;
		}
		public static function OutElastic (t:Number, b:Number, c:Number, d:Number, a:Number, p:Number, ... args):Number {
			if (t==0) return b;  if ((t/=d)==1) return b+c;  if (!p) p=d*.3;
			if (!a || a < Math.abs(c)) { a=c; var s:Number = p/4; }
			else 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);
		}
		public static function InOutElastic (t:Number, b:Number, c:Number, d:Number, a:Number, p:Number, ... args):Number {
			if (t==0) return b;  if ((t/=d/2)==2) return b+c;  if (!p) p=d*(.3*1.5);
			if (!a || a < Math.abs(c)) { a=c; var s:Number = p/4; }
			else 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;
		}
		//Expo
		public static function InExpo (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			return (t==0) ? b : c * Math.pow(2, 10 * (t/d - 1)) + b;
		}
		public static function OutExpo (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			return (t==d) ? b+c : c * (-Math.pow(2, -10 * t/d) + 1) + b;
		}
		public static function InOutExpo (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			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;
		}
		//Linear
		public static function Linear (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			return c*t/d + b;
		}
		public static function InLinear (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			return c*t/d + b;
		}
		public static function OutLinear (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			return c*t/d + b;
		}
		public static function InOutLinear (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			return c*t/d + b;
		}
		//Quad
		public static function InQuad (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			return c*(t/=d)*t + b;
		}
		public static function OutQuad (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			return -c *(t/=d)*(t-2) + b;
		}
		public static function InOutQuad (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			if ((t/=d/2) < 1) return c/2*t*t + b;
			return -c/2 * ((--t)*(t-2) - 1) + b;
		}
		//Quart
		public static function InQuart (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			return c*(t/=d)*t*t*t + b;
		}
		public static function OutQuart (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			return -c * ((t=t/d-1)*t*t*t - 1) + b;
		}
		public static function InOutQuart (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			if ((t/=d/2) < 1) return c/2*t*t*t*t + b;
			return -c/2 * ((t-=2)*t*t*t - 2) + b;
		}
		//Quint
		public static function InQuint (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			return c*(t/=d)*t*t*t*t + b;
		}
		public static function OutQuint (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			return c*((t=t/d-1)*t*t*t*t + 1) + b;
		}
		public static function InOutQuint (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			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;
		}
		//Sine
		public static function InSine (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			return -c * Math.cos(t/d * (Math.PI/2)) + c + b;
		}
		public static function OutSine (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			return c * Math.sin(t/d * (Math.PI/2)) + b;
		}
		public static function InOutSine (t:Number, b:Number, c:Number, d:Number, ... args):Number {
			return -c/2 * (Math.cos(Math.PI*t/d) - 1) + b;
		}
		

		//... args are to help easily account for/incorporate the few functions that take more than 4 args.

	}
}