Bug 37772 – WebGL rendering context does not activate unless accelerated compositing is enabled from settings.

• Component: WebGL
• Status: RESOLVED FIXED

[Jarkko Sakkinen]

When QtLauncher is used (for example) web pages that have WebGL content don't load unless accelerated compositing is enabled from QWebSettings.

[Jarkko Sakkinen]

I have an idea about cause of this bug. Posting patch as soon as I have verified that it fixes the issue.

[Jarkko Sakkinen]

Created attachment 53861 [details]
Allows creation of WebGL rendering context if webGLEnabled flag is true and does not also require acceleratedCompositing flag also to be true.

[Simon Hausmann]

It looks like the original change from bug https://bugs.webkit.org/show_bug.cgi?id=35759 was intentional...

[Chris Marrin]

Comment on attachment 53861 [details]
Allows creation of WebGL rendering context if webGLEnabled flag is true and does not also require acceleratedCompositing flag also to be true.

> diff --git a/WebCore/ChangeLog b/WebCore/ChangeLog
> index 82feb24..22c8c71 100644
> --- a/WebCore/ChangeLog
> +++ b/WebCore/ChangeLog
> @@ -1,3 +1,17 @@
> [phone]  Jarkko Sakkinen  <[e-mail]>
> +
> +        Reviewed by NOBODY (OOPS!).
> +
> +        [Qt] WebGL rendering context does not activate unless accelerated compositing is enabled from settings.
> +        https://bugs.webkit.org/show_bug.cgi?id=37772
> +        
> +        Allows WebGL rendering context creation is webGLEnabled flag
> +        is true in the document settings and does not require 
> +        also acceleratedCompositing flag also to be enabled.
> +
> +        * html/HTMLCanvasElement.cpp:
> +        (WebCore::HTMLCanvasElement::getContext):
> +
>  2010-04-19  Kevin Ollivier  <[e-mail]>
>  
>          Fix the Mac builders for now by restoring the keepAlive function.
> diff --git a/WebCore/html/HTMLCanvasElement.cpp b/WebCore/html/HTMLCanvasElement.cpp
> index ef85323..5367040 100644
> --- a/WebCore/html/HTMLCanvasElement.cpp
> +++ b/WebCore/html/HTMLCanvasElement.cpp
> @@ -145,7 +145,7 @@ CanvasRenderingContext* HTMLCanvasElement::getContext(const String& type, Canvas
>      }
>  #if ENABLE(3D_CANVAS)    
>      Settings* settings = document()->settings();
> -    if (settings && settings->webGLEnabled() && settings->acceleratedCompositingEnabled()) {
> +    if (settings && settings->webGLEnabled()) {
>          // Accept the legacy "webkit-3d" name as well as the provisional "experimental-webgl" name.
>          // Once ratified, we will also accept "webgl" as the context name.
>          if ((type == "webkit-3d") ||

The Mac implementation requires acceleratedCompositing for WebGL rendering. It's reasonable to remove the test for acceleratedCompositing here as long as, for the Mac platform, webGLEnabled has a test to prevent it from being true unless acceleratedCompositing is also true.

[Kenneth Russell]

Comment on attachment 53861 [details]
Allows creation of WebGL rendering context if webGLEnabled flag is true and does not also require acceleratedCompositing flag also to be true.

This change looks fine. I'm surprised Chromium's WebGL support wasn't broken by the original patch.

[Simon Hausmann]

Comment on attachment 53861 [details]
Allows creation of WebGL rendering context if webGLEnabled flag is true and does not also require acceleratedCompositing flag also to be true.

It does not appear that this patch takes Chris' commen into account:

"The Mac implementation requires acceleratedCompositing for WebGL rendering. It's reasonable to remove the test for acceleratedCompositing here as long as, for the Mac platform, webGLEnabled has a test to prevent it from being true unless acceleratedCompositing is also true."

So landing this fix would re-open Bug 35759

[Kenneth Russell]

(In reply to comment #6)
> (From update of attachment 53861 [details])
> It does not appear that this patch takes Chris' commen into account:
> 
> "The Mac implementation requires acceleratedCompositing for WebGL rendering. It's reasonable to remove the test for acceleratedCompositing here as long as, for the Mac platform, webGLEnabled has a test to prevent it from being true unless acceleratedCompositing is also true."
> 
> So landing this fix would re-open Bug 35759

Note that in https://bugs.webkit.org/show_bug.cgi?id=40085 a patch was landed adding an #ifdef around the test of accelerated compositing being enabled. You could add another arm to the #if with something like

#if !PLATFORM(CHROMIUM) && !PLATFORM(QT)

Or, if you're willing to do the build plumbing, you could completely generalize this into a new build flag per https://bugs.webkit.org/show_bug.cgi?id=40091 .

[Jarkko Sakkinen]

Created attachment 58122 [details]
Based on suggestion by Kenneth Russel

[WebKit Commit Bot]

Comment on attachment 58122 [details]
Based on suggestion by Kenneth Russel

Clearing flags on attachment: 58122

Committed r60930: <http://trac.webkit.org/changeset/60930>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Simon Hausmann]

WebGL is not part of the qtwebkit-2.0 branch, so I'm removing this bug from the list of bugs/patches to include in the release branch.