1624988 - The combination of CSS filters blur & drop-shadow disappear when a new video frame is rendered

Status: VERIFIED FIXED

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

Description

[Wessel Kroos]

Attachment: Firefox 74 - CSS filters blur and drop-shadow - Incorrect frame render.png

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.149 Safari/537.36

Steps to reproduce:

Go to: https://codepen.io/wesselkroos/pen/KKpGReq
You can see the red squire's drop-shadow flickering when he meets the canvas blur after ~5 animations.

Actual results:

The red square's drop-shadow is not rendered where the blur and the drop-shadow overlap each other when a new video frame is rendered and the drop-shadow filter has already been rendered in a previous animation frame.

There is a similar issue in Chromium. I've reported it here: https://bugs.chromium.org/p/chromium/issues/detail?id=1064390

Expected results:

The red square's css filter drop-shadow should still be overlapping the canvas's css filter blur.

Comment 1

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

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

Comment 2

[Bryce Seager van Dyk [:bryce] (he/him) - Not reading bugmail]

Reverting automatic component assignment as I don't think this is a media issue. My guess would be that it's related to CSS, or rendering, but will leave it for manual triage as I'm not certain.

Comment 3

[Alice0775 White]

I can reproduce if WebRender ON.

Comment 4

[Alice0775 White]

#1 Regression window(drop-shadow flicker over video):
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=7cdfad033225137286badb9ac136c2a9eb1c1e1c&tochange=a1da279eb08b0fcaec352e8f9ffd8d63c0e673d3

#2 Regression window(the #1 flicker seems fixed, but white rectangle appears and disappears):
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=1330041fa8973ac2a56f074a7c1eee9bb1cff151&tochange=93ccc760c4dd69f63d6ac171ace357b0dd31412a

Comment 5

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

The priority flag is not set for this bug.
:jbonisteel, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 6

[Jessie [:jbonisteel] pls NI]

Glenn, are you still looking at this?

Comment 7

[Glenn Watson [:gw]]

I've been focused on the hd4600 work, but yea, I'll take a look at this next week.

Comment 8

[Glenn Watson [:gw]]

Attachment: A smaller standalone repro case

Comment 9

[Glenn Watson [:gw]]

The issue is that drop shadow primitives don't correctly inflate their local rectangle for primitive dependency calculations.

I could make a band-aid fix this this that fixes the simple case (where there's just a blur radius, and no offset), but that won't always work correctly in cases where the drop-shadow has an offset (or more than one drop-shadow on a single primitive).

Unfortunately, the code that deals with inflation of blur and drop-shadow primitives is a bit of a mess, which complicates fixing this properly. I'm going to see if I can tidy this up a bit in a way that will fix this and make the code more maintainable / correct for these cases.

Comment 10

[Glenn Watson [:gw]]

Attachment: Bug 1624988 - Improve inflation factor calculation for drop-shadows.

Include the inflation factor from all drop-shadow filters when
calculating the overall inflation factor for a surface.

This doesn't fix cases with large offsets, which is a larger amount
of work to fix, but it fixes the common case and the referenced
case in this bug.

Comment 11

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/f75deee57611
Improve inflation factor calculation for drop-shadows. r=kvark

Comment 12

[Stefan Hindli [:stefan_hindli]]

Backed out changeset f75deee57611 (Bug 1624988) for wrench bustages CLOSED TREE

https://treeherder.mozilla.org/#/jobs?repo=autoland&resultStatus=testfailed%2Cbusted%2Cexception&classifiedState=unclassified&revision=e2fd427507a19ec39bb1cd21c7733922954ae229

https://treeherder.mozilla.org/#/jobs?repo=autoland&resultStatus=testfailed%2Cbusted%2Cexception&classifiedState=unclassified&selectedJob=298910001

https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=298910001&repo=autoland&lineNumber=998

Comment 13

[Glenn Watson [:gw]]

I had updated and done a try with a fix for that android fuzziness, but had forgotten to push the updated patch to phabricator. I've done that now, so hopefully it should pass this time.

Comment 14

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/c4f20b2600e1
Improve inflation factor calculation for drop-shadows. r=kvark

Comment 15

[Noemi Erli[:noemi_erli]]

https://hg.mozilla.org/mozilla-central/rev/c4f20b2600e1

Comment 16

[Marcela (Please NI request to Brindusa Tot)]

I managed to reproduce the issue using an older version of Nightly 76.0a1 on Windows 10 x64.
I retested using Nightly 77.0a1 and latest Nightly 78.0a1 on Windows 10 x64. The issue is not reproducing anymore.

Comment 17

[Wessel Kroos]

Thanks for the fix Glenn! I've verified the fix in Nightly 78 as well.