| <!DOCTYPE html> |
| <meta charset="utf-8"> |
| <title>Composition of transform animations</title> |
| <link rel="help" href="https://drafts.csswg.org/css-transforms-2/#combining-transform-lists"> |
| <meta name="assert" content="transform animations should composite correctly"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| |
| <div id="target"><div> |
| |
| <script> |
| test(() => { |
| var anim1 = target.animate( |
| { transform: [ 'translateX(0)', 'translateX(100px)' ]}, |
| 1000 |
| ); |
| var anim2 = target.animate( |
| { transform: [ 'translateY(0)', 'translateY(100px)' ]}, |
| {duration: 1000, composite: 'add'} |
| ); |
| |
| anim1.pause(); |
| anim2.pause(); |
| |
| anim1.currentTime = 200; |
| anim2.currentTime = 800; |
| |
| // The computation here should be: |
| // underlying_value = 'translateX(0)' --> 'translateX(100px)' @ 0.2 |
| // = 'translateX(20px)' |
| // final_value = 0.2 * ('translateX(20px) translateY(0)') + |
| // 0.8 * ('translateX(20px) translateY(100px)') |
| // = 'translateX(20px) translateY(80px)' |
| // = 'matrix(1, 0, 0, 1, 20, 80)' |
| assert_equals(getComputedStyle(target).transform, 'matrix(1, 0, 0, 1, 20, 80)') |
| }, 'An additive transform animation on-top of a replace transform animation ' + |
| 'should composite correctly'); |
| </script> |
