Throttled requestAnimationFrame

throttled-raf.js

// Usage:
//
//   var onScroll = traf(function () {
//     item[0].style.width = window.scrollY + 100 + 'px';
//   })
//   window.addEventListener('scroll', onScroll, false);

export default function traf (fn) {
  var ticking = false;
  
  return function () {
    if(!ticking) {
      ticking = true;
      requestAnimationFrame(function () {
        ticking = false;
        fn()
      });
    }
  }
}

• https://css-tricks.com/debouncing-throttling-explained-examples/
• http://codepen.io/dcorb/pen/pgOKKw