<div id="block">click me</div>
#block{
  	position:absolute;
    left: 50%;
    top: 50%;
    width: 100px;
    height: 100px;
    margin: -50px 0 0 -50px;
    background: #0c8;
    line-height: 100px;
    text-align: center;
    color: #fff;
    cursor: pointer;
    border-radius: 100%;
}
  function Animator(duration, progress, easing){
    this.duration = duration;
    this.progress = progress;
    this.easing = easing || function(p){return p};
  }
  
  Animator.prototype = {
  	start: function(finished){
      var startTime = Date.now();
      var duration = this.duration,
          self = this;
      
      requestAnimationFrame(function step(){
      	var p = (Date.now() - startTime) / duration;
        var next =  true;
        
        if(p < 1.0){
          self.progress(self.easing(p), p);
        }else{
          if(typeof finished === 'function'){
          	next = finished() === false;
          }else{
          	next = finished === false;
          }
          
          if(!next){
            self.progress(self.easing(1.0), 1.0);
          }else{
            startTime += duration;
            self.progress(self.easing(p), p);
          }
        }
        
        if(next) requestAnimationFrame(step);
      });
    }
  };

  var easing = BezierEasing(0.86, 0, 0.07, 1);
  //easeInOutQuint

  var a1 = new Animator(2000, function(ep,p){
    var x = 200 * ep;
    
    block.style.transform = 'translateX(' + x + 'px)';
  }, easing);
  
  
  block.addEventListener('click', function(){
	a1.start();
  });

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

  1. http://s3.qhimg.com/!bfe40c57/bezier-easing.min.js