Closed Bug 1595965 Opened 1 year ago Closed 1 year ago

White square at bottom right in about:support when os compositor was enabled on Windows.

Categories

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

Unspecified
Windows 10
defect

Tracking

()

RESOLVED FIXED
mozilla72
Tracking Status
firefox72 --- fixed

People

(Reporter: sotaro, Assigned: gw)

References

Details

Attachments

(3 files, 1 obsolete file)

I saw it with latest nightly.

STR

  • [1] Start Firefox with os compositor enabled on Windows.
    • gfx.webrender.compositor: true
  • [2] Move to about:support

Actual result

  • White square at bottom right in about:support.
  • It seemed to happen when Firefox window was a certain size. Then if the problem does not happen, we could try resizing window horizontally.

Expected result

  • No white square at bottom right
Blocks: 1592509
Attached image screenshot

Screenshot when the white square appeared.

I tried mozregression, but I am not sure which change caused the problem.

./mach mozregression --good 2019-10-20 --pref gfx.webrender.all:true gfx.webrender.compositor:true -a about:support

https://hg.mozilla.org/mozilla-central/pushloghtml?changeset=caf55914ccddba34d462a1206530d7868b6c4992

There was another STR to cause white square.

STR

  • [1] Start Firefox with os compositor enabled on Windows. But window is not maximized.
    • gfx.webrender.compositor: true
  • [2] Move to a page like about: support
  • [3] Enable menu bar
  • [4] Select "Find in This Page" in Edit menu.

Actual result

  • White square at bottom in about:support. When window was not maximized, the issue did not happen.
  • It seemed to happen when Firefox window was a certain size. Then if the problem does not happen, we could try resizing window horizontally or vertically.

Expected result

  • No white square at bottom

From the symptom, it seemed that some tiles of content were not rendered.

OS: Unspecified → Windows
Priority: -- → P3
OS: Windows → Windows 10
Attached image screenshot of comment 3
Attachment #9108338 - Attachment description: screenshot → screenshot of comment 3

:gw, can you reproduce the problem? Comment 3 was easy to reproduce. I could reproduce the issue on my all Win10 PCs.

Flags: needinfo?(gwatson)

Yes, I can reproduce this. I'll investigate today, thanks for the STR!

Assignee: nobody → gwatson
Flags: needinfo?(gwatson)
Attachment #9108344 - Attachment is obsolete: true

In Draw compositor mode, tiles are placed into a bucket based on
the tile kind and/or opacity. This simplifies the renderer code
for this mode, which uses the z-buffer to reject opaque tiles.

In native compositor mode, the tiles need to be submitted in the
correct draw order. Opacity is a property of the native surface,
and should not affect the order the tiles are added to the visual
tree of the native compositor.

Pushed by gwatson@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/e7837d7a78c6
Fix tile draw order with native compositor mode. r=sotaro
Status: NEW → RESOLVED
Closed: 1 year ago
Resolution: --- → FIXED
Target Milestone: --- → mozilla72
QA Whiteboard: [good first verify]

Fix Verified [testday-20191220]

You need to log in before you can comment on or make changes to this bug.