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

The Working Group just discussed `Presentation attribute as start or end value of a CSS transition`, and agreed to the following:

* `RESOLVED: use edge behavior`
* `RESOLVED: make this rotate with 3 values transition to a matrix and do matrix decomposition`

<details><summary>The full IRC log of that discussion</summary>
&lt;dael> Topic: Presentation attribute as start or end value of a CSS transition<br>
&lt;dael> github: https://github.com/w3c/csswg-drafts/issues/2684<br>
&lt;dael> krit: In SVG we have the transform attribute which is a presentation attr which mean sit contributes to css pipeline and we can set a transform and it would interfere in hierarchy with itself.<br>
&lt;dael> krit: If we have a transform with a list and define a transition on the same element, should it take transofrm into account or just ignore? I'm asking for ignore. 2 browsers do that and 2 take it into account.<br>
&lt;krit> https://codepen.io/krit/pen/XqvqyG?editors=1100<br>
&lt;dael> krit: codepen^<br>
&lt;dael> krit: You can see that there's a transform on the rect and a transition in css. For webkit you see it transforms and then transforms. blink and edge take the transform from the transform attr and then transition to the value.<br>
&lt;dael> krit: I'd like to ignore as that makes the most sense. So can a transform attr contribute as a start or end value?<br>
&lt;dael> krit: I'm asking for edge or blink behavior.<br>
&lt;dael> astearns: Conserns with standardizing on blink or edge?<br>
&lt;dael> smfr: Good to match other presentation attributes<br>
&lt;chris> LGTM<br>
&lt;dael> astearns: And there's a Mozilla comment saying it's because they haven't made transform a presentation element yet<br>
&lt;dael> RESOLVED: use edge behavior<br>
&lt;dael> krit: Syntax and some transform are different then on css. Example is rotate which is 1 value in css, 3 in SVG.<br>
&lt;dael> krit: If we have a transition from a transform presentation attribute with 3 value rotate to css, css would not understand. Edge here ignores the origin so the element jumps and then contiues. Blink composes from one matrix to another<br>
&lt;dael> krit: Webkit and FF ignore.<br>
&lt;dael> krit: Proposal would be to make this rotate with 3 values to a matrix and do matrix decomposition<br>
&lt;dael> astearns: This is an edge case b/c 3 value isn't used much?<br>
&lt;chris> rrsagent, here<br>
&lt;RRSAgent> See https://www.w3.org/2018/06/20-css-irc#T16-53-26<br>
&lt;dael> krit: Yes. Edge case because css does not have 3 value so it's not often used.<br>
&lt;dael> smfr: Unfortunate that you fall back to matrix for something that's a rotate...you'll never do rotate [missed] turning into rotate translate<br>
&lt;dael> krit: You could change rotate to a rotate translate, but that could be worse becuase it doesn't match any transform function. So we'd still fallback<br>
&lt;TabAtkins> (I support the rotate(3-arg) being incompatible with anything.)<br>
&lt;dael> krit: Proposal is if there's a rotate with 3 values and have a transition it gets composed to a matrix and we have matrix decomposition for a animation<br>
&lt;dael> smfr: No alternate proposal and I don't object. It's okay, it's just that if author is trying to rotate we will fallback<br>
&lt;dael> krit: Can we agree on matix decomposition?<br>
&lt;dael> astearns: Objections to make this rotate with 3 values to a matrix and do matrix decomposition<br>
&lt;chris> ok I guess<br>
&lt;dael> RESOLVED: make this rotate with 3 values transition to a matrix and do matrix decomposition<br>
</details>


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Received on Wednesday, 20 June 2018 16:56:43 UTC