1454706 - rendering glitch -CSS slide flip

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, defect, P2)

Comment 1

[Alice0775 White]

Attachment: screenshot

Back face is visible during animate

Comment 2

[Alice0775 White]

Attachment: screenshot

this demo is also affected
http://desandro.github.io/3dtransforms/examples/cube-02-show-sides.html

Comment 3

[Darkspirit]

http://desandro.github.io/3dtransforms/examples/card-02-slide-flip.html
http://desandro.github.io/3dtransforms/examples/cube-02-show-sides.html
I think both are duplicates of bug 1431582, but I'm not sure.

Comment 4

[Glenn Watson [:gw]]

I think this is probably fixed by the changes for https://bugzilla.mozilla.org/show_bug.cgi?id=1442916 (https://github.com/servo/webrender/pull/2997). I still see some flickering, but I think that's a separate issue from the back face being visible.

Comment 5

[Aria Beingessner [:Gankra]]

hey glenn, another candidate for "check if your 3d-transforms branch fixes this"

Comment 6

[Maire Reavy [:mreavy]]

We can't release this to the field, but we can let this ride to beta.

Comment 7

[Glenn Watson [:gw]]

From a quick look with current 3d transforms branch, all the pages linked above do appear to be working correctly. However, I didn't look super closely, I may have missed something. We can check in detail once the 3d transforms patch lands.

Comment 8

[Darkspirit]

Last piece: Text still flickers and is shining through. https://codepen.io/desandro/pen/LmWoWe

Comment 9

[Darkspirit]

Maybe this needs both bug 1489937 ( servo/webrender#3040 ) and bug 1490242 ( servo/webrender#3030 ) ?
I haven't found a try build with both.

Comment 10

[Glenn Watson [:gw]]

Yes, I believe this relies on https://github.com/servo/webrender/issues/3040 which hasn't landed yet.

Comment 11

[Darkspirit]

Not fixed in bug 1490640 comment 1.

Comment 12

[Aria Beingessner [:Gankra]]

Gonna look into this deeper, since this looks like it's probably a good counterexample to my work in #3040

Comment 13

[Aria Beingessner [:Gankra]]

oops, didn't mean to hit submit yet

ok so this looks like this and hackerone are the same bug

specifically the fact that the "front" text is backface-visible is a subtle point of disagreement between chrome and firefox (we match the spec, they don't, but also they are sort of the defacto spec)

so the only bug is that we're Z-fighting, just like hackerone

Comment 14

[Aria Beingessner [:Gankra]]

Attachment: testcase.html

reduced testcase demonstrating that this bug is a mix of Z-fighting and also the ::before background getting which side is its "back" backwards.

Comment 15

[Dzmitry Malyshau [:kvark]]

Produced the fix in https://github.com/servo/plane-split/pull/24

Comment 16

[Dzmitry Malyshau [:kvark]]

Wow, looks like my fix made it through the night, and it's already in 65.0a1 (2018-10-24) (64-bit). Kudos to :kats!