css/css-images/object-position-interpolation.html

<!DOCTYPE html>
<meta charset="UTF-8">
<link rel="help" href="https://drafts.csswg.org/css-images-3/#the-object-position">
<meta name="test" content="object-position supports animation">

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

<body></body>

<script>
  // Default object-position value is 50% 50%
  test_interpolation({
    property: 'object-position',
    from: neutralKeyframe,
    to: 'left top',
  }, [
    { at: -0.25, expect: '62.5% 62.5%' },
    { at: 0, expect: '50% 50%' },
    { at: 0.25, expect: '37.5% 37.5%' },
    { at: 0.5, expect: '25% 25%' },
    { at: 0.75, expect: '12.5% 12.5%' },
    { at: 1, expect: '0% 0%' },
    { at: 1.25, expect: '-12.5% -12.5%' },
  ]);

  // Animate x axis
  test_interpolation({
    property: 'object-position',
    from: 'initial',
    to: 'center top',
  }, [
    { at: -0.25, expect: '50% 62.5%' },
    { at: 0, expect: '50% 50%' },
    { at: 0.25, expect: '50% 37.5%' },
    { at: 0.5, expect: '50% 25%' },
    { at: 0.75, expect: '50% 12.5%' },
    { at: 1, expect: '50% 0%' },
    { at: 1.25, expect: '50% -12.5%' },
  ]);

  // Animate y axis
  test_interpolation({
    property: 'object-position',
    from: 'initial',
    to: 'left center',
  }, [
    { at: -0.25, expect: '62.5% 50%' },
    { at: 0, expect: '50% 50%' },
    { at: 0.25, expect: '37.5% 50%' },
    { at: 0.5, expect: '25% 50%' },
    { at: 0.75, expect: '12.5% 50%' },
    { at: 1, expect: '0% 50%' },
    { at: 1.25, expect: '-12.5% 50%' },
  ]);

  // Pixel values
  test_interpolation({
    property: 'object-position',
    from: '20px 20px',
    to: '100px 100px',
  }, [
    { at: -0.25, expect: '0px 0px' },
    { at: 0, expect: '20px 20px' },
    { at: 0.25, expect: '40px 40px' },
    { at: 0.5, expect: '60px 60px' },
    { at: 0.75, expect: '80px 80px' },
    { at: 1, expect: '100px 100px' },
    { at: 1.25, expect: '120px 120px' },
  ]);
</script>