https://gist.github.com/gre/1650294
http://www.gizma.com/easing/#circ1
// 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;
};