Re: [csswg-drafts] [css-transforms-1] Presentation attribute as start or end value of a CSS transition

## Test
I created a test case here: https://codepen.io/krit/pen/XqvqyG?editors=1100

The behavior is different across browsers:

| Interpolation | `transform="rotate(45) scale(2)"` **to** `transform: rotate(3turn) scale(1)`  |
| ------------- |:----------------------------------------------------------------------------- |
| WebKit        | `transform` attribute gets ignored; _from_-value turns to `none`.<sub>1</sub> |
| Blink         | Interpolation per transform - as speced.                                      |
| Gecko         | `transform` attribute gets ignored; _from_-value turns to `none`.             |
| Edge          | Interpolation per transform - as speced.                                      |

1. After the transition back to _from_ the value doesn't get reset to attribute value.

| Interpolation | `transform="rotate(45 50 50) scale(2)"` **to** `transform: rotate(3turn) scale(1)`      |
| ------------- |:--------------------------------------------------------------------------------------- |
| WebKit        | `transform` attribute gets ignored; _from_-value turns to `none`.<sub>1</sub>           |
| Blink         | No interpolation.                                                                       |
| Gecko         | `transform` attribute gets ignored; _from_-value turns to `none`.                       |
| Edge          | Interpolation per transform. _from_-value **ignores** translation of `rotate(45 50 50)` |

1. After the transition back to _from_ the value doesn't get reset to attribute value.

## Conclusion
* Blink and Edge do interpolation per transform function for all CSS supported transform functions as speced.
* No implementation does fall back to matrix decomposition if `rotate()` has translation/origin values.

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Received on Sunday, 27 May 2018 06:49:36 UTC