text: // Robert Penner's easeInOutQuad
  
  // find the rest of his easing functions here: http://robertpenner.com/easing/
  // find them exported for ES6 consumption here: https://github.com/jaxgeller/ez.js
  
  export default (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
  }
  