1716648 - repeating-linear-gradient is stretched in big containers in firefox 90

Status: RESOLVED FIXED

(Core :: Graphics, defect, P3)

Description

[Marc Ahlers]

Attachment: test.html

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:90.0) Gecko/20100101 Firefox/90.0

Steps to reproduce:

Firefox 90b7.

Use a repeating-linear-gradient with absolute pixel stop values inside a container bigger than 1000px. (Tested >1500px).

See attached test.html for a bunch of test cases, in which it is broken most of the time.

Note: It behaves correctly in Firefox 89.

Actual results:

It will get stretched, scale buggy and miss some color-stops.

Expected results:

The repeating-linear-gradient should always look the same, regardless of the size of the div. Each gradient in the example file attached should look exactly the same.

Comment 1

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

The Bugbug bot thinks this bug should belong to the 'Core::Graphics' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Comment 2

[Timothy Nikkel (:tnikkel)]

https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=acc3fea06c51cbb852dbc72db586dee6dc3d2494&tochange=0d70eec51094acb1caf8c73642937c1a0637d2c6

Comment 3

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

Set release status flags based on info from the regressing bug 1708959

Comment 4

[Marco Castelluccio [:marco]]

Jim, can you set a priority and severity for this bug?

Comment 5

[Marco Castelluccio [:marco]]

On Matrix, Nical said he is inclined to wontfix for 90 because "it's a rendering artifact that affect very large gradients and is mostly visible when there are hard gradient gradient stops. You'll find those here and there but it's not all over the web".

Comment 6

[Nicolas Silva [:nical]]

Attachment: Bug 1716648 - Avoid stretching with large linear gradients in some cases. r=#gfx-reviewers

The tile size edtermines the number of pixels we allocate for the gradinrt pattern, and is eventually clamped to a maximum value. Minimizing the tile size after other transformations avoids some cases where we request more area than we need.

Comment 7

[Nicolas Silva [:nical]]

Attachment: Bug 1716648 - Don't cache large linear gradients with hard stops. r=#gfx-reviewers

Very large gradients are rendered at a lower resolution which is fine for most gradients as they tend to be smooth transitions, but looks bad when there are hard stops.

Depends on D119627

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/8582a1d2caa7
Avoid stretching with large linear gradients in some cases. r=gfx-reviewers,lsalzman
https://hg.mozilla.org/integration/autoland/rev/0e7b638d0012
Don't cache large linear gradients with hard stops. r=gfx-reviewers,lsalzman

Comment 9

[Dorel Luca [:dluca]]

https://hg.mozilla.org/mozilla-central/rev/8582a1d2caa7
https://hg.mozilla.org/mozilla-central/rev/0e7b638d0012

Comment 10

[Nicolas Silva [:nical]]

Comment on attachment 9230720 [details]
Bug 1716648 - Don't cache large linear gradients with hard stops. r=#gfx-reviewers

Beta/Release Uplift Approval Request

• User impact if declined: visual artifacts on some linear gradients
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: Yes
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): simple patch.
• String changes made/needed:

Comment 11

[Pascal Chevrel:pascalc (PTO until April 26)]

Comment on attachment 9230720 [details]
Bug 1716648 - Don't cache large linear gradients with hard stops. r=#gfx-reviewers

Approved for 91 beta 3, thanks.

Comment 12

[Pascal Chevrel:pascalc (PTO until April 26)]

https://hg.mozilla.org/releases/mozilla-beta/rev/31792e0b7e74
https://hg.mozilla.org/releases/mozilla-beta/rev/772e4e11c8db