scrollTop js

scrollTop.js

function scrollTo(to = 0, duration= 1000) {
  const start = window.pageYOffset;
  const change = to - start;
  const increment = 20;
  let currentTime = 0;

  const animateScroll = (() => {
    currentTime += increment;
    const val = Math.easeInOutQuad(currentTime, start, change, duration);
    
    window.scroll(0, val)

    if (currentTime < duration) {
      requestAnimationFrame(animateScroll);
    }
  });
  requestAnimationFrame(animateScroll);
};

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;
};