797231 - Clip path region is incorrect with direct2d

Status: RESOLVED FIXED

(Core :: SVG, defect)

Description

[Brian Birtles (:birtles)]

Attachment: Incorrect rendering (direct2D enabled)

In Firefox 16 and later the rendering of some paths with clip paths is incorrect. With Direct2D disabled the rendering is correct.

In the test URL, the countries towards the top of the planet are clipped by an elliptical path. On my work machine, these countries do not appear at all. On another machine, the right-hand two thirds only appear.

Comment 1

[Brian Birtles (:birtles)]

Attachment: Correct rendering (direct2D disabled)

Comment 2

[Jonathan Watt [:jwatt]]

So it seems both clipping and masking (bug 779029) are broken with Direct2D? That's pretty serious. Any chance you can look into these any time soon, Bas?

Comment 3

[Bas Schouten (:bas.schouten)]

Could you try switching on/off Azure content? (gfx.content.azure.enabled)

Comment 4

[Bas Schouten (:bas.schouten)]

(In reply to Jonathan Watt [:jwatt] from comment #2)
> So it seems both clipping and masking (bug 779029) are broken with Direct2D?
> That's pretty serious. Any chance you can look into these any time soon, Bas?

This is most likely a consequence of the terribly convoluted way the SVG code uses the gfxContext. Most likely we're not simulating some cairo behavior around state management correctly with the Thebes-Azure wrapper. I'll have a look.

Comment 5

[Jonathan Watt [:jwatt]]

Attachment: Reftest as a patch

Reduced testcase as a reftest for Bas. Will need to be landed after any patch that Bas comes up with.

Comment 6

[Bas Schouten (:bas.schouten)]

Attachment: Don't overwrite mPathTransform if the transform already changed.

Restore will change the transform and mark it changed as well as store the old transform. It will, intentionally, however leave the PathBuilder in place. This would cause a subsequent transform to overwrite mPathTransform with the wrong transform.

Comment 7

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/4cc97bf59962

Comment 8

[Jonathan Watt [:jwatt]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/779b6ddfb118

Comment 9

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/779b6ddfb118

++

Comment 10

[Bas Schouten (:bas.schouten)]

Comment on attachment 667534 [details] [diff] [review]
Don't overwrite mPathTransform if the transform already changed.

[Approval Request Comment]
Bug caused by (feature/regressing bug #): Bug 715768
User impact if declined: Incorrect rendering in some SVG cases.
Testing completed (on m-c, etc.): Aurora
Risk to taking this patch (and alternatives if risky): Need to switch off azure reducing performance.
String or UUID changes made by this patch: None

Comment 11

[Lukas Blakk [:lsblakk] use ?needinfo]

Comment on attachment 667534 [details] [diff] [review]
Don't overwrite mPathTransform if the transform already changed.

Please land asap so this is in tomorrow's Beta.

Comment 12

[Jonathan Watt [:jwatt]]

Pushed https://hg.mozilla.org/releases/mozilla-beta/rev/9340e498ee62

Comment 13

[Simona Badau, Desktop QA]

Verified on Firefox 17 RC that the clip path region is properly displayed with or without direct2d.

Mozilla/5.0 (Windows NT 6.1; rv:17.0) Gecko/17.0 Firefox/17.0
Build ID: 20121116115405

Comment 14

[Simona Badau, Desktop QA]

Mozilla/5.0 (Windows NT 6.1; rv:18.0) Gecko/20100101 Firefox/18.0

Verified as fixed on Firefox 18 beta 3 - the clip path region is properly displayed with or without direct2d.