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Re: [css-transforms] CSS3D breaks with opacity flattening

From: Rik Cabanier <cabanier@gmail.com>
Date: Thu, 22 Sep 2016 12:37:20 +0100
Message-ID: <CAGN7qDCVhs2KJTf1GDgVG28H3UysQn6615Wh4X9nv2AFpSdyow@mail.gmail.com>
To: Matt Woodrow <mwoodrow@mozilla.com>
Cc: Tien-Ren Chen <trchen@chromium.org>, "Tab Atkins Jr." <jackalmage@gmail.com>, "/#!/JoePea" <trusktr@gmail.com>, Chris Harrelson <chrishtr@google.com>, Simon Fraser <simon.fraser@apple.com>, "public-fx@w3.org" <public-fx@w3.org>
On Thu, Sep 22, 2016 at 11:53 AM, Matt Woodrow <mwoodrow@mozilla.com> wrote:

>
>
> On 22/09/16 9:00 PM, Rik Cabanier wrote:
>
>
>
> I think you just showed that Matt's proposal can be emulated with the
> current spec.
>
>
> I don't think this is true. Firstly, this example still wasn't as good as
> I think mine could be. Secondly, it requires complex matrix manipulation by
> the author, which basically rules out animations/transitions.
>

 That's true. Tien-Ren's math skills are quite impressive :-)

> Given that:
>
>    - this is shipping in Chrome [1]
>    - Safari committed to support it [2]
>    - Edge is in favor  [3]
>    - Firefox has already implemented it [4]
>    - your new proposal is more complex to implement and hard to understand
>    - your new proposal can be emulated
>
>
> I agreed (and changed Firefox) under the assumption that little to no web
> content would be affected.
>

That still holds true: https://www.chromestatus.com/metrics/
feature/popularity#OpacityWithPreserve3DQuirk
Current usage is 0.0036% of all page loads.
Reading the thread on Blink's intent to ship [1], because of overcounting,
the number of affected sites is even less and some of the firefox bug
reports are because of other FF issues. [2]
Also, content WAS already broken on the web since there were 4
non-compatible implementations.

In addition, your proposal *also* affects web content because opacity is
now applied to the group instead of being distributed to the children.


> This thread was started by an author who's content was broken, so it seems
> reasonable to re-visit these assumptions.
>

Yes, we went over his examples and told him how to fix it (= apply opacity
to the elements)
Since Firefox knows that it's flattening, could it create a warning in the
console and point to an MDN page with more information?

1:
https://groups.google.com/a/chromium.org/forum/#!msg/blink-dev/eBIp90_il1o/jrxzMW_4BQAJ
<https://groups.google.com/a/chromium.org/forum/#!msg/blink-dev/eBIp90_il1o/jrxzMW_4BQAJ>
2: https://bugzilla.mozilla.org/show_bug.cgi?id=1250718
https://bugzilla.mozilla.org/show_bug.cgi?id=1278021
https://bugzilla.mozilla.org/show_bug.cgi?id=1229317
Received on Thursday, 22 September 2016 11:37:51 UTC

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