Bug 111566 – [Texturemapper] transform-style 'flat' value is broken

• Component: Layout and Rendering
• Status: RESOLVED FIXED

[Bruno Abinader (history only)]

CSS3 3D Transform's "transform-style" property, when used with 'flag' value has recently broken on WebKit. You can verify by running the example from Surfin' Safari blog [1] and noticing the weird white boxes drawn while hovering mouse (or a single tap on mobile mode, as confirmed by Rafael) over the rotating div. I'm going to bisect the code to find the dangling patch.

Links:
[1] https://www.webkit.org/blog-files/3d-transforms/transform-style.html

[Bruno Abinader (history only)]

I've bisected the code and found out that a fix for a patch that avoids redundant state clipping was causing the issue ( http://trac.webkit.org/changeset/144290 ), from bug 111065. Reverting the patch solves the issue, however like Allan commented, it breaks clipping on some Apple HTML5 examples (i.e. http://www.apple.com/html5/showcase/transitions/ ).

[Bruno Abinader (history only)]

Created attachment 191834 [details]
Patch

Proposed patch

[Noam Rosenthal]

Comment on attachment 191834 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=191834&action=review

> Source/WebCore/platform/graphics/texmap/TextureMapperGL.cpp:1097
> +    m_clipStack.apply(m_context3D.get(), false);

This is a boolean trap.
I prefer to have apply(...) and applyIfNeeded(...). From bindDefaultSurface we'd call apply, and from everywhere else applyIfNeeded.

[Bruno Abinader (history only)]

Created attachment 191976 [details]
Patch

Added applyIfNeeded() to avoid boolean trap as reviewed by Noam

[Bruno Abinader (history only)]

Created attachment 191980 [details]
Patch

ChangeLog typo fixes as reviewed by Allan

[Allan Sandfeld Jensen]

Comment on attachment 191980 [details]
Patch

LGTM

[Bruno Abinader (history only)]

Created attachment 191981 [details]
Patch

Patch for landing (last minute ChangeLog typo fix)

[WebKit Review Bot]

Comment on attachment 191981 [details]
Patch

Clearing flags on attachment: 191981

Committed r145071: <http://trac.webkit.org/changeset/145071>

[Bruno Abinader (history only)]

All reviewed patches have been landed.  Closing bug.