Les equations effets élastiques ease in / ease out

// simple linear tweening - no easing, no acceleration

Math.linearTween = function (t, b, c, d) 
	return c*t/d + b ;
 ;
		

// quadratic easing in - accelerating from zero velocity

Math.easeInQuad = function (t, b, c, d) 
	t /= d ;
	return c*t*t + b ;
 ;
		

// quadratic easing out - decelerating to zero velocity

Math.easeOutQuad = function (t, b, c, d) 
	t /= d ;
	return -c * t*(t-2) + b ;
 ;
		

// quadratic easing in/out - acceleration until halfway, then deceleration

Math.easeInOutQuad = function (t, b, c, d) 
	t /= d/2 ;
	if (t < 1) return c/2*t*t + b ;
	t— ;
	return -c/2 * (t*(t-2) - 1) + b ;
 ;

// cubic easing in - accelerating from zero velocity

Math.easeInCubic = function (t, b, c, d) 
	t /= d ;
	return c*t*t*t + b ;
 ;
		

// cubic easing out - decelerating to zero velocity

Math.easeOutCubic = function (t, b, c, d) 
	t /= d ;
	t— ;
	return c*(t*t*t + 1) + b ;
 ;
		

// cubic easing in/out - acceleration until halfway, then deceleration

Math.easeInOutCubic = function (t, b, c, d) 
	t /= d/2 ;
	if (t < 1) return c/2*t*t*t + b ;
	t -= 2 ;
	return c/2*(t*t*t + 2) + b ;
 ;
	

// quartic easing in - accelerating from zero velocity

Math.easeInQuart = function (t, b, c, d) 
	t /= d ;
	return c*t*t*t*t + b ;
 ;
		

// quartic easing out - decelerating to zero velocity

Math.easeOutQuart = function (t, b, c, d) 
	t /= d ;
	t— ;
	return -c * (t*t*t*t - 1) + b ;
 ;
		

// quartic easing in/out - acceleration until halfway, then deceleration

Math.easeInOutQuart = function (t, b, c, d) 
	t /= d/2 ;
	if (t < 1) return c/2*t*t*t*t + b ;
	t -= 2 ;
	return -c/2 * (t*t*t*t - 2) + b ;
 ;

// quintic easing in - accelerating from zero velocity

Math.easeInQuint = function (t, b, c, d) 
	t /= d ;
	return c*t*t*t*t*t + b ;
 ;
		

// quintic easing out - decelerating to zero velocity

Math.easeOutQuint = function (t, b, c, d) 
	t /= d ;
	t— ;
	return c*(t*t*t*t*t + 1) + b ;
 ;
		

// quintic easing in/out - acceleration until halfway, then deceleration

Math.easeInOutQuint = function (t, b, c, d) 
	t /= d/2 ;
	if (t < 1) return c/2*t*t*t*t*t + b ;
	t -= 2 ;
	return c/2*(t*t*t*t*t + 2) + b ;
 ;
		

// sinusoidal easing in - accelerating from zero velocity

Math.easeInSine = function (t, b, c, d) 
	return -c * Math.cos(t/d * (Math.PI/2)) + c + b ;
 ;
		

// sinusoidal easing out - decelerating to zero velocity

Math.easeOutSine = function (t, b, c, d) 
	return c * Math.sin(t/d * (Math.PI/2)) + b ;
 ;
		

// sinusoidal easing in/out - accelerating until halfway, then decelerating

Math.easeInOutSine = function (t, b, c, d) 
	return -c/2 * (Math.cos(Math.PI*t/d) - 1) + b ;
 ;
		

// exponential easing in - accelerating from zero velocity

Math.easeInExpo = function (t, b, c, d) 
	return c * Math.pow( 2, 10 * (t/d - 1) ) + b ;
 ;
		

// exponential easing out - decelerating to zero velocity

Math.easeOutExpo = function (t, b, c, d) 
	return c * ( -Math.pow( 2, -10 * t/d ) + 1 ) + b ;
 ;
		

// exponential easing in/out - accelerating until halfway, then decelerating

Math.easeInOutExpo = function (t, b, c, d) 
	t /= d/2 ;
	if (t < 1) return c/2 * Math.pow( 2, 10 * (t - 1) ) + b ;
	t— ;
	return c/2 * ( -Math.pow( 2, -10 * t) + 2 ) + b ;
 ;
		

// circular easing in - accelerating from zero velocity

Math.easeInCirc = function (t, b, c, d) 
	t /= d ;
	return -c * (Math.sqrt(1 - t*t) - 1) + b ;
 ;
		

// circular easing out - decelerating to zero velocity

Math.easeOutCirc = function (t, b, c, d) 
	t /= d ;
	t— ;
	return c * Math.sqrt(1 - t*t) + b ;
 ;
		

// circular easing in/out - acceleration until halfway, then deceleration

Math.easeInOutCirc = function (t, b, c, d) 
	t /= d/2 ;
	if (t < 1) return -c/2 * (Math.sqrt(1 - t*t) - 1) + b ;
	t -= 2 ;
	return c/2 * (Math.sqrt(1 - t*t) + 1) + b ;
 ;