Function initAnim

examples/dolls/dolls.js:56–83

(el)

});

function initAnim(el){
  var start = performance.now()
  var last = 0;
  var lastTop = 0;
  var tick = function(){
    var diff = performance.now() - last;

    if (!last || diff > 50){
      last = performance.now();

      var nextTop = 50 * Math.sin((last - start) / 1000);

      var curTop = parseFloat(el.style.top || 0);
      var topChange = nextTop - lastTop;
      lastTop = nextTop;

      var top = curTop + topChange;

      el.style.top = top + 'px';

      Tether.position();
    }

    requestAnimationFrame(tick);
  };

  tick();
}