css/css-paint-api/custom-property-animation-on-main-thread.https.html

<!DOCTYPE html>
<html class="reftest-wait">
<link rel="help" href="https://drafts.css-houdini.org/css-paint-api/">
<link rel="match" href="one-custom-property-animation-ref.html">
<style>
.container {
  width: 100px;
  height: 100px;
  animation: expand 5s;
}
@keyframes expand {
  0% { --foo: 0; }
  0.01% { --foo: 50; }
  99% { --foo: 50; }
  100% { --foo: 100; }
}

#canvas-geometry {
  background-color: blue;
  background-image: paint(geometry);
}
</style>
<script src="/common/reftest-wait.js"></script>
<script src="/common/worklet-reftest.js"></script>
<body>
<div id="canvas-geometry" class="container"></div>

<script id="code" type="text/worklet">
registerPaint('geometry', class {
  static get inputProperties() { return ['--foo']; }
  paint(ctx, geom, properties) {
    let fooValue = parseFloat(properties.get('--foo').toString());
    ctx.fillStyle = 'green';
    ctx.fillRect(0, 0, fooValue, fooValue);
  }
});
</script>

<script>
CSS.registerProperty({
  name: '--foo',
  syntax: '<number>',
  initialValue: '0',
  inherits: false
});
</script>

<script>
// The test is designed to make sure that when the custom property animation is
// running on the compositor thread, we are getting the right value.
// The "importWorkletAndTerminateTestAfterAsyncPaint" has the logic to rAF
// two frames before taking a screenshot. So the animation is designed to
// be stable after two frames. That is, the 0.01% of 5s is much less than
// two frames, and thus after two frames, the value of --foo should be stable.
importWorkletAndTerminateTestAfterAsyncPaint(CSS.paintWorklet, document.getElementById('code').textContent);
</script>
</body>
</html>