var Easing = {
	
	// LINEAR TWEEN
	linearTween:  function (t, b, c, d) 
	{
		return c * t / d + b;
	},

	// QUADRATIC EASING: t^2
	easeInQuad:  function (t, b, c, d) 
	{
		return c * (t /= d) * t + b;
	},
	easeOutQuad:  function (t, b, c, d) 
	{
		return -c * (t /= d) * (t - 2) + b;
	},
	easeInOutQuad:  function (t, b, c, d) 
	{
		if ((t /= d / 2) < 1) 
			return c / 2 * t * t + b;
		return -c / 2 * ((--t) * (t - 2) - 1) + b;
	},
	
	// CUBIC EASING: t^3
	easeInCubic:  function (t, b, c, d) 
	{
		return c * (t /= d) * t * t + b;
	},
	easeOutCubic:  function (t, b, c, d) 
	{
		return c * ((t = t / d-1) * t * t + 1) + b; 
	},
	easeInOutCubic:  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;
	},
	
	// QUARTIC EASING: t^4	
	easeInQuart:  function (t, b, c, d) 
	{
		return c * (t /= d) * t * t * t + b;
	},
	easeOutQuart:  function (t, b, c, d) 
	{
		return -c * ((t = t / d - 1) * t * t * t - 1) + b;
	},
	easeInOutQuart:  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;
	},

	// QUINTIC EASING: t^5
	easeInQuint:  function (t, b, c, d) 
	{
		return c * (t /= d) * t * t * t * t + b;
	},	
	easeOutQuint:  function (t, b, c, d) 
	{
		return c*((t=t/d-1)*t*t*t*t + 1) + b;
	},
	easeInOutQuint:  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;
	},
		
	// SINUSOIDAL EASING: sin(t)
	easeInSine:  function (t, b, c, d) 
	{
		return -c * Math.cos(t/d * (Math.PI/2)) + c + b;
	},
	easeOutSine:  function (t, b, c, d) 
	{
		return c * Math.sin(t/d * (Math.PI/2)) + b;
	},
	easeInOutSine:  function (t, b, c, d) 
	{
		return -c/2 * (Math.cos(Math.PI*t/d) - 1) + b;
	},
	
	
	// EXPONENTIAL EASING: 2^t
	easeInExpo:  function (t, b, c, d)
	{
		return (t==0) ? b : c * pow(2, 10 * (t/d - 1)) + b;
	},
	easeOutExpo:  function (t, b, c, d) {
		return (t==d) ? b+c : c * (-pow(2, -10 * t/d) + 1) + b;
	},
	easeInOutExpo:  function (t, b, c, d)
	{
		if (t==0) return b;
		if (t==d) return b+c;
		if ((t/=d/2) < 1) return c/2 * pow(2, 10 * (t - 1)) + b;
		return c/2 * (-pow(2, -10 * --t) + 2) + b;
	},
	
	
	// CIRCULAR EASING: sqrt(1-t^2)
	easeInCirc:  function (t, b, c, d) 
	{
		return -c * (Math.sqrt(1 - (t/=d)*t) - 1) + b;
	},
	easeOutCirc:  function (t, b, c, d) 
	{
		return c * Math.sqrt(1 - (t=t/d-1)*t) + b;
	},
	easeInOutCirc:  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;
	},
	
	
	// ELASTIC EASING: exponentially decaying sine wave
	easeInElastic:  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 < abs(c)) { a=c; var s=p/4; }
		else var s = p/(2*PI) * asin (c/a);
		return -(a*pow(2,10*(t-=1)) * sin( (t*d-s)*(2*PI)/p )) + b;
	},
	easeOutElastic:  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 < abs(c)) { a=c; var s=p/4; }
		else var s = p/(2*PI) * asin (c/a);
		return a*pow(2,-10*t) * sin( (t*d-s)*(2*PI)/p ) + c + b;
	},
	easeInOutElastic:  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 < abs(c)) { a=c; var s=p/4; }
		else var s = p/(2*PI) * asin (c/a);
		if (t < 1) return -.5*(a*pow(2,10*(t-=1)) * sin( (t*d-s)*(2*PI)/p )) + b;
		return a*pow(2,-10*(t-=1)) * sin( (t*d-s)*(2*PI)/p )*.5 + c + b;
	},
	
	
	// BACK EASING: overshooting cubic easing: (s+1)*t^3 - s*t^2
	easeInBack:  function (t, b, c, d, s) 
	{
		if (s == undefined) s = 1.70158;
		return c*(t/=d)*t*((s+1)*t - s) + b;
	},
	easeOutBack:  function (t, b, c, d, s) 
	{
		if (s == undefined) s = 1.70158;
		return c*((t=t/d-1)*t*((s+1)*t + s) + 1) + b;
	},
	easeInOutBack:  function (t, b, c, d, s) 
	{
		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 EASING: exponentially decaying parabolic bounce
	easeInBounce:  function (t, b, c, d) 
	{
		return c - easeOutBounce (d-t, 0, c, d) + b;
	},
	easeOutBounce:  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;
		}
	},
	easeInOutBounce:  function (t, b, c, d) 
	{
		if (t < d/2) return easeInBounce (t*2, 0, c, d) * .5 + b;
		return easeOutBounce (t*2-d, 0, c, d) * .5 + c*.5 + b;
	}

}