1440690 - Don't build WebRender display list if the gecko display list hasn't changed

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, enhancement, P1)

Description

[Jeff Muizelaar [:jrmuizel]]

This is the webrender analog to bug 1429932.

Comment 1

[Jeff Muizelaar [:jrmuizel]]

Miko, are you able to look at doing this?

Comment 2

[Miko Mynttinen]

It seems nsDisplayList::PaintRoot() needs to somehow handle nsDisplayList::PAINT_IDENTICAL_DISPLAY_LIST from aFlags, and skip the call/propagate the flag to wrManager->EndTransactionWithoutLayer().
I am not very familiar with this code, so I do not know what the graceful way of skipping this step is, but I can give it a look.

Comment 3

[Kartikaya Gupta (email:[e-mail])]

It looks like the WR equivalent should be pretty much the same as the non-WR code. That is, you'll want to check for the flag just before [1] and then call WebRenderLayerManager::EndEmptyTransaction [2]. The code in the WR branch of PaintRoot was modeled after the existing code in the non-WR branch and should follow the pattern pretty closely.

[1] https://searchfox.org/mozilla-central/rev/14d933246211b02f5be21d2e730a57cf087c6606/layout/painting/nsDisplayList.cpp#2670
[2] https://searchfox.org/mozilla-central/rev/14d933246211b02f5be21d2e730a57cf087c6606/gfx/layers/wr/WebRenderLayerManager.cpp#189

Comment 4

[Miko Mynttinen]

Attachment: Bug 1440690 - Don't build WebRender display list if the gecko display list hasn't changed

Review commit: https://reviewboard.mozilla.org/r/235008/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/235008/

Comment 5

[Kartikaya Gupta (email:[e-mail])]

Comment on attachment 8966264 [details]
Bug 1440690 - Don't build WebRender display list if the gecko display list hasn't changed

https://reviewboard.mozilla.org/r/235008/#review240638

::: layout/painting/nsDisplayList.cpp:2627
(Diff revision 1)
>            return nullptr;
>          }
>        }
>      }
>  
> +    bool temp =

Let's rename "temp" to something better since we're increasing the distance from definition to use.

Comment 6

[Miko Mynttinen]

Comment on attachment 8966264 [details]
Bug 1440690 - Don't build WebRender display list if the gecko display list hasn't changed

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/235008/diff/1-2/

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/a4af53b3f62d
Don't build WebRender display list if the gecko display list hasn't changed r=kats

Comment 8

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/a4af53b3f62d