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

From: Matt Woodrow <mwoodrow@mozilla.com>
Date: Mon, 19 Sep 2016 19:22:29 +1200
To: "Tab Atkins Jr." <jackalmage@gmail.com>
Cc: Rik Cabanier <cabanier@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>
Message-ID: <678c051a-3b2d-7307-6e3a-b499fd43706f@mozilla.com>
On 19/09/16 6:27 PM, Tab Atkins Jr. wrote:
> No, as I explained in more detail in the GitHub thread I linked
> <https://github.com/w3c/svgwg/issues/264#issuecomment-246750601>, this
> is a logical consequence of 'opacity' and other filter-type effects
> being "group effects".  If you want the effect to only apply to the
> leaves, you can do that yourself by specifying it on the leaves, but
> it has a visibly different effect than doing it "as a group".
Sorry, I'm not quite sure I follow. The idea I proposed explicitly 
*doesn't* break the group nature of opacity, which is why I think it's 
worth discussing.

The example I gave had opacity applied to an intermediate element, and 
showed the internal representation needed to apply it as a group while 
maintaining preserve-3d.

Are there more complex examples you can think of where this breaks down?

>> Obviously this would prevent depth sorting occurring between elements inside
>> and outside of 'b', and we need to figure out how to depth sort 'b' itself
>> (given that it is an atomic entry for sorting, but isn't a 2d plane), but
>> those seem solvable.
> That's actually the core problem preventing this from working; it's
> not a detail we can just paper over later.
Which part of this? The first piece is the exact same situation we have 
when we flatten for opacity, so I don't see how that's a problem. The 
latter is somewhat difficult from an implementation standpoint, but it's 
not obvious that it's a showstopper.

- Matt
Received on Monday, 19 September 2016 07:23:03 UTC

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