Roll In

The element rolls in from the side, turning like a wheel as it travels and slowing to a stop in its place. It turns exactly as far as a wheel of its size would, so round things look right.

New

How to use it

Paste the snippet just before </head>.
Add data-roll-in to any element. Round ones, like badges and avatars, look the most natural.

Options

Add any of these attributes to the same element.

`data-from`	The side it rolls in from: `left` or `right`. Give both, `left right`, and each loop uses the next. Default `left`.
`data-distance`	Roll this many px instead of starting fully off screen.
`data-turns`	Make this many turns instead of turning true to the distance.
`data-duration`	How long the roll takes. Default 1300 ms.
`data-delay`	Wait before the first entrance. Default 0 ms.
`data-loop`	Hold, fade away and roll in again.
`data-hold`	How long it stays before fading, when looping. Default 1400 ms.

It starts just past the edge of the nearest container that clips its overflow (overflow: hidden or clip), or of the window if there isn’t one. Put it in a clipping wrapper, or give the page overflow-x: clip, so it can’t make the page scroll sideways while it’s off screen.

1 · Snippet

<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/bundles/anime.umd.min.js"></script>
<script>
  (function () {
    // Roll In: the element rolls in from the side, turning like a wheel as it
    // travels: one full turn for every circumference it covers.
    // Usage: <div data-roll-in>…</div>
    // Round elements look most natural. It starts just past the edge of the
    // nearest container that clips its overflow (overflow: hidden or clip),
    // or of the window.
    // Optional: data-from ("left", default, or "right"; give both, "left
    // right", and each loop uses the next), data-distance (px to roll instead
    // of from off screen), data-turns (turns to make instead of rolling true
    // to the distance), data-duration (ms, default 1300), data-delay (ms
    // before the first entrance), data-loop (hold, fade away and roll in
    // again), data-hold (ms to stay when looping, default 1400).
    var DEFAULTS = { from: 'left', duration: 1300, delay: 0, hold: 1400 };

    function reduced() {
      return window.matchMedia('(prefers-reduced-motion: reduce)').matches;
    }

    // The box the element must leave to be "off screen".
    function clipBox(el) {
      for (var p = el.parentElement; p && p !== document.body; p = p.parentElement) {
        var s = getComputedStyle(p);
        if (s.overflowX !== 'visible' || s.overflowY !== 'visible') return p.getBoundingClientRect();
      }
      return { left: 0, top: 0, right: window.innerWidth, bottom: window.innerHeight };
    }

    function enter(el, from, done) {
      var d = el.dataset;
      var t = +d.duration || DEFAULTS.duration;
      var r = el.getBoundingClientRect();
      var c = clipBox(el);
      var dir = from === 'right' ? 1 : -1;
      var dist = +d.distance || (dir > 0 ? c.right - r.left : r.right - c.left) + 8;
      // A wheel turns one radian for every radius it rolls.
      var radius = Math.min(r.width, r.height) / 2 || 1;
      var deg = d.turns ? +d.turns * 360 : dist / radius * 180 / Math.PI;
      anime.utils.set(el, { x: dir * dist, rotate: dir * deg, opacity: 0 });
      anime.animate(el, {
        x: { to: 0, ease: 'out(3)' },
        rotate: { to: 0, ease: 'out(3)' },
        opacity: { to: 1, duration: t * 0.25, ease: 'linear' },
        duration: t,
        onComplete: done
      });
    }

    function cycle(el) {
      var d = el.dataset;
      var s = el._rli;
      var froms = (d.from || DEFAULTS.from).split(/[\s,]+/);
      enter(el, froms[s.n++ % froms.length], function () {
        if (d.loop === undefined || d.loop === 'false') return;
        setTimeout(function () {
          anime.animate(el, {
            opacity: 0,
            duration: 400,
            ease: 'out(2)',
            onComplete: function () {
              // Wait until it's back on screen before the next entrance.
              setTimeout(function () {
                if (s.visible) cycle(el);
                else s.waiting = true;
              }, 500);
            }
          });
        }, +d.hold || DEFAULTS.hold);
      });
    }

    function init() {
      var io = new IntersectionObserver(function (entries) {
        entries.forEach(function (e) {
          var s = e.target._rli;
          s.visible = e.isIntersecting;
          if (!e.isIntersecting) return;
          if (!s.started) {
            s.started = true;
            setTimeout(function () { cycle(e.target); }, +e.target.dataset.delay || DEFAULTS.delay);
          } else if (s.waiting) {
            s.waiting = false;
            cycle(e.target);
          }
        });
      }, { threshold: 0.2 });
      document.querySelectorAll('[data-roll-in]').forEach(function (el) {
        if (el._rli) return;
        el._rli = { n: 0 };
        if (reduced()) return;
        anime.utils.set(el, { opacity: 0 });
        io.observe(el);
      });
    }

    if (document.readyState === 'loading') document.addEventListener('DOMContentLoaded', init);
    else init();
  })();
</script>

2 · Your HTML

<div class="badge" data-roll-in>New</div>

<!-- or from the right, with exactly one turn: -->
<div class="badge" data-roll-in data-from="right" data-turns="1">New</div>