1389139 - Provide transform/perspective information to APZ in layers-free mode

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, enhancement, P3)

Description

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

Right now when we create layers-free WR transaction, we put together a tree of scroll data information [1] to send over to APZ. This scroll data includes things that APZ needs to know such as the scroll metadata for a particular scrollable frame. One of the things currently missing from this data structure is the transform information. We need to create WebRenderLayerScrollData nodes with transform/perspective information so that on the compositor side APZ knows what things are transformed and can adjust coordinates accordingly.

[1] http://searchfox.org/mozilla-central/rev/c329d562fb6c6218bdb79290faaf015467ef89e2/gfx/layers/wr/WebRenderLayerManager.cpp#284

Comment 1

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

Attachment: Bug 1389139 - Add support for transform and perspective display items to layers-free APZ.

A basic sanity check here seems to produce the correct behaviour but I'm
not at all confident that this will always do the correct thing in more
complex cases or when perspectives are involved. However this is hard to
test and get working without the testing infrastructure up and running
so I'd rather land this simple code first and then dig into the more
complex cases once we have a way to catch regressions.

Review commit: https://reviewboard.mozilla.org/r/169198/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/169198/

Comment 2

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

Attachment: Bug 1389139 - Add transforms for reflayer equivalents in the layers-free APZ world.

In normal gecko, RefLayer instances also have a transform, which needs
to be propagated to APZ in layers-free mode.

Review commit: https://reviewboard.mozilla.org/r/169200/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/169200/

Comment 3

[Jeff Muizelaar [:jrmuizel]]

Comment on attachment 8897914 [details]
Bug 1389139 - Add support for transform and perspective display items to layers-free APZ.

https://reviewboard.mozilla.org/r/169198/#review174606

Comment 4

[Jeff Muizelaar [:jrmuizel]]

Comment on attachment 8897915 [details]
Bug 1389139 - Add transforms for reflayer equivalents in the layers-free APZ world.

https://reviewboard.mozilla.org/r/169200/#review174608

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/47af683d76df
Add support for transform and perspective display items to layers-free APZ. r=jrmuizel
https://hg.mozilla.org/integration/autoland/rev/21377565dbae
Add transforms for reflayer equivalents in the layers-free APZ world. r=jrmuizel

Comment 6

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/47af683d76df
https://hg.mozilla.org/mozilla-central/rev/21377565dbae