Bug 56339 – [Qt] WebGL content not shown when accelerated compositing is enabled

• Status: RESOLVED
• Resolution: FIXED
• Component: Layout and Rendering

[Jarkko Sakkinen]

Before, the class GraphicsLayer had functions:

    virtual void setContentsToGraphicsContext3D(const GraphicsContext3D*);
    virtual void setGraphicsContext3DNeedsDisplay();

Now these are gone and a new function have been added:

    virtual void setContentsToCanvas(PlatformLayer*);

This causes a problem because PlatformLayer is defined as QGraphicsObject. This gives no way to acquire FBO texture of GraphicsContext3D.

[Jarkko Sakkinen]

Internal QGraphicsObject derived class that blits the FBO into QPixmap might solve this. I'm going to try out this solution.

[Jarkko Sakkinen]

I'm going to try following:

- Remove deprecated functions from GraphicsLayerQt (see description)
- Remove Canvas3DContentType and all the code that uses it.
- Implement setContentsToCanvas() that simply calls setContentsToMedia().
- Inside GraphicsContext3DQt.cpp create QGraphicsObject implementation.

[Jarkko Sakkinen]

Started writing fix for this issue. I hope I'll get something out tomorrow.

[Jarkko Sakkinen]

Initial implementation works (fixes the issue) but patch is not ready *yet*. Time to test how call sequences go with different options.

[Jarkko Sakkinen]

Update: I adjusted code so that only for accelerated compositing texture mapping is used. For other cases memory copy is used. The point for this is that only with that configuration the direct texture mapping is stable with transformations of the webkit rendering pipeline. I think this is how it should work. Conservative support for non accelerated pipeline and GPU assisted blitting for accelerated compositing pipeline.

[Jarkko Sakkinen]

At least that is the best compromise in order to get this releasable state :)

[Jarkko Sakkinen]

Tested that calls only paint() and paintIntoCanvas() when AC is enabled. Seems to work correctly.

[Jarkko Sakkinen]

Created attachment 85802 [details]
Fixes the issue by adapting to internal API changes.

Direct texture mapping enabled only for AC with QGLWidget viewport case. Other cases use memory copy.

[Noam Rosenthal]

LGTM

[Jarkko Sakkinen]

I'll revise the patch a bit:
- There was a merge conflict in GraphicsContext3DQt.cpp with latest upstream version. Fixing this.
- Removing #include "GraphicsContext3D.h" from GraphicsLayerQt.h. Not needed anymore.

[Jarkko Sakkinen]

Created attachment 85941 [details]
Made adjustments mentioned in comments section

[Jarkko Sakkinen]

Created attachment 85943 [details]
forgot changelog entry from previous patch.

[Kenneth Rohde Christiansen]

Comment on attachment 85943 [details]
forgot changelog entry from previous patch.

View in context: https://bugs.webkit.org/attachment.cgi?id=85943&action=review

> Source/WebCore/ChangeLog:7
> +

Would be good with a bit of summary of what you actually did

[Jarkko Sakkinen]

Created attachment 85982 [details]
Added description what the changeset actually does.

I think it now describes in a nutshell what is happening.

[Kenneth Rohde Christiansen]

(In reply to comment #14)
> Created an attachment (id=85982) [details]
> Added description what the changeset actually does.
> 
> I think it now describes in a nutshell what is happening.

Great! :-)

[WebKit Commit Bot]

Comment on attachment 85982 [details]
Added description what the changeset actually does.

Clearing flags on attachment: 85982

Committed r81298: <http://trac.webkit.org/changeset/81298>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[WebKit Review Bot]

http://trac.webkit.org/changeset/81298 might have broken SnowLeopard Intel Release (Tests)
The following tests are not passing:
http/tests/filesystem/resolve-uri.html