<!DOCTYPE html>
<meta charset="utf-8">
<title>offset-rotate composition</title>
<link rel="author" title="Eric Willigers" href="mailto:ericwilligers@chromium.org">
<link rel="help" href="https://drafts.fxtf.org/motion-1/#offset-rotate-property">
<meta name="assert" content="offset-rotate supports animation.">

<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/css/support/interpolation-testcommon.js"></script>

<body>
<script>
// Angle rotations compose.
test_composition({
  property: 'offset-rotate',
  underlying: '20deg',
  addFrom: '10deg',
  addTo: '20deg',
}, [
  {at: -0.3, expect: '27deg'},
  {at: 0, expect: '30deg'},
  {at: 0.3, expect: '33deg'},
  {at: 0.6, expect: '36deg'},
  {at: 1, expect: '40deg'},
  {at: 1.5, expect: '45deg'},
]);

// Angle rotations don't compose with underlying 'auto'.
test_composition({
  property: 'offset-rotate',
  underlying: 'auto 20deg',
  addFrom: '10deg',
  addTo: '20deg',
}, [
  {at: -0.3, expect: '7deg'},
  {at: 0, expect: '10deg'},
  {at: 0.3, expect: '13deg'},
  {at: 0.6, expect: '16deg'},
  {at: 1, expect: '20deg'},
  {at: 1.5, expect: '25deg'},
]);

// Auto rotations compose with underlying 'auto'.
test_composition({
  property: 'offset-rotate',
  underlying: 'auto 20deg',
  addFrom: 'reverse 10deg',
  addTo: 'auto 20deg',
}, [
  {at: -0.3, expect: 'auto 261deg'},
  {at: 0, expect: 'auto 210deg'},
  {at: 0.3, expect: 'auto 159deg'},
  {at: 0.6, expect: 'auto 108deg'},
  {at: 1, expect: 'auto 40deg'},
  {at: 1.5, expect: 'auto -45deg'},
]);

// When we can't interpolate, we can't compose.
test_composition({
  property: 'offset-rotate',
  underlying: '20deg',
  addFrom: 'reverse 10deg',
  addTo: '20deg',
}, [
  {at: -0.3, expect: 'auto 190deg'},
  {at: 0, expect: 'auto 190deg'},
  {at: 0.3, expect: 'auto 190deg'},
  {at: 0.6, expect: '40deg'},
  {at: 1, expect: '40deg'},
  {at: 1.5, expect: '40deg'},
]);

test_composition({
  property: 'offset-rotate',
  underlying: '20deg',
  replaceFrom: 'reverse 10deg',
  addTo: '20deg',
}, [
  {at: -0.3, expect: 'auto 190deg'},
  {at: 0, expect: 'auto 190deg'},
  {at: 0.3, expect: 'auto 190deg'},
  {at: 0.6, expect: '40deg'},
  {at: 1, expect: '40deg'},
  {at: 1.5, expect: '40deg'},
]);

// Angle rotations compose with underlying angle.
test_composition({
  property: 'offset-rotate',
  underlying: '20deg',
  addFrom: '10deg',
  replaceTo: '10deg',
}, [
  {at: -0.3, expect: '36deg'},
  {at: 0, expect: '30deg'},
  {at: 0.3, expect: '24deg'},
  {at: 0.6, expect: '18deg'},
  {at: 1, expect: '10deg'},
  {at: 1.5, expect: '0deg'},
]);
</script>
</body>
