Re: [css-transforms] Handling combined opacity and preserve-3d

On Thu, May 26, 2016 at 4:09 PM Matt Woodrow <[email protected]> wrote:

>
> On 27/05/16 5:03 AM, Chris Harrelson wrote:
>
>
> Hi Matt/Simon/Rossen/all,
>
> I'm the lead for paint/compositing integration in Blink.
>
> TL;DR:
> - Blink/Chrome would like to change its implementation to have opacity
> force flattening, and AIUI match what Firefox was doing before this
> Mozilla bug <https://bugzilla.mozilla.org/show_bug.cgi?id=1250718> wax
> recently fixed.
> - We'd like other implementations to make the change also if there is
> consensus.
>
> As noted already in this thread, this changed behavior matches the latest
> spec, is more well-defined and rational, and significantly reduces the
> complexity of Blink's implementation. (Matt, from reading the Mozilla bug,
> I think you would agree?)
>
> Other implementers: does this change sound good? Would you be willing to
> commit to changing behavior if it is web compatible enough? (We are already
> collecting compatibility data in the Canary & Dev channels).
>
> Here is one example:
> Before <http://jsbin.com/tabuxo/edit?html,output>
> After <http://jsbin.com/tekuratiba/1/edit?html,output>
>
> Our work is tracked in this bug
> <https://bugs.chromium.org/p/chromium/issues/detail?id=612956>.
>
>
> Firefox only temporarily had that behaviour, it was a regression due to a
> refactoring we did. We reverted to matching the current Blink/WebKit
> behaviour since we had reports of real sites breaking because of it.
>

So far the data seems to show a very small impact. I'll update next week
with some actual numbers.


>
> I do agree that this change is the preferable behaviour though, so will be
> interested in the results of the compatability data you're collecting.
>

Great. Simon/Rossen, what do you think?


>
>
> - Matt
>