1780702 - Canvas element sometimes invisible

Status: RESOLVED DUPLICATE of bug 1782443

(Core :: Graphics: Canvas2D, defect)

Description

[jonrandy]

Attachment: canvas.mp4

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:104.0) Gecko/20100101 Firefox/104.0

Steps to reproduce:

Load a page with a dynamically created canvas. See https://codepen.io/jonrandy/full/ExQpZMy for an example

Actual results:

Sometimes the canvas does not appear, although previews of the canvas (when dragging a tab or hovering over the canvas in the inspector) indicate that the canvas is working. Duplicating the problematic tab seems to resolve the issue every time

Expected results:

The canvas should work as expected every time - like it does in the main Firefox release and in other browsers

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'DevTools::Inspector' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Jamie Nicol [:jnicol]]

Confirmed with mozregression to be caused by bug 1770088.

Thanks for the bug report, Jon. This appears to be due to switching on our new experimental GPU-accelerated canvas renderer in nightly. While we work on a fix, you can switch back to the old canvas renderer by setting gfx.canvas.accelerated to false in about:config.

Comment 3

[jonrandy]

Thanks for the workaround. It's been making development somewhat awkward for me. Looking forward to a fix

Comment 4

[Sotaro Ikeda [:sotaro]]

Attachment: patch_tmp_canvas

With the temporal patch, the problem was addressed for me.
From it, DrawTargetWebgl::mWebglValid might not be updated as expected.

Comment 5

[BugBot [:suhaib / :marco/ :calixte]]

Set release status flags based on info from the regressing bug 1770088

Comment 6

[BugBot [:suhaib / :marco/ :calixte]]

The bug has a release status flag that shows some version of Firefox is affected, thus it will be considered confirmed.

Comment 7

[Lee Salzman [:lsalzman]]

Can you please attach your "about:support" information? I am having trouble reproducing this.

Comment 8

[Lee Salzman [:lsalzman]]

Okay, I figured out why I was having trouble reproducing this, because I already fixed it locally... :)

Duping this to bug 1782443 which will fix it.