1607777 - Incorrect CARenderer rendering

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, task)

Description

[Markus Stange [:mstange]]

There are three small problems in the implementation of NativeLayerRootSnapshotterCA::ReadbackPixels from bug 1592026. This can result in wrong reftest snapshots, and after bug 1592031 in incorrect profiler screenshots.

Comment 1

[Markus Stange [:mstange]]

Attachment: Bug 1607777 - When using CARenderer on HiDPI, pass device pixels to the glOrtho call and use a sublayerTransform on the root CALayer. r=jrmuizel

The CARenderer documentation does not provide any guidance on how to use CARenderer with different resolutions.
In the initial implementation I simply tried the following: Make a device-pixel sized framebuffer, call glViewport with the device pixel size, and then call glOrtho with the "point" size. And this seemed to work.
However, it doesn't always work. When hooking up profiler screenshots, I noticed that in some cases, some layers would just not be rendered. Sometimes I even saw layers show up in wrong places.
After this patch, these problems no longer appear.

Depends on D58518

Comment 2

[Markus Stange [:mstange]]

Attachment: Bug 1607777 - Fix CARenderer invalidation when the buffer size changes. r=jrmuizel

addUpdateRect needs to be called after beginFrame, otherwise it doesn't do anything.

Depends on D59154

Comment 3

[Markus Stange [:mstange]]

Attachment: Bug 1607777 - Clear areas that CARenderer repaints, so that old content doesn't accomulate in transparent areas such as the tab bar. r=jrmuizel

I consider this to be a bug in CARenderer. According to https://stackoverflow.com/questions/56150363/rendering-animated-calayer-off-screen-using-carenderer-with-mtltexture the Metal implementation has the same bug.

Depends on D59155

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/6f0faedf53bd
When using CARenderer on HiDPI, pass device pixels to the glOrtho call and use a sublayerTransform on the root CALayer. r=jrmuizel
https://hg.mozilla.org/integration/autoland/rev/53c427440d0e
Fix CARenderer invalidation when the buffer size changes. r=jrmuizel
https://hg.mozilla.org/integration/autoland/rev/bcb85259be95
Clear areas that CARenderer repaints, so that old content doesn't accomulate in transparent areas such as the tab bar. r=jrmuizel

Comment 5

[Andreea Pavel [:apavel]]

https://hg.mozilla.org/mozilla-central/rev/6f0faedf53bd
https://hg.mozilla.org/mozilla-central/rev/53c427440d0e
https://hg.mozilla.org/mozilla-central/rev/bcb85259be95