Bug 154147 – [GTK] Allow applications to disable Accelerated Compositing mode

• Status: RESOLVED
• Resolution: FIXED
• Component: WebKitGTK

[Carlos Alberto Lopez Perez]

In bug 150558 we added the possibility to force AC to be always on if the environment variable WEBKIT_FORCE_COMPOSITING_MODE is defined.

Sometimes, because of bad graphics drivers or other grahpic related bugs (for example see bug 126122) it may be desirable to do the contrary thing: force AC to be off.

So I'm proposing here to add another variable, lets name it WEBKIT_DISABLE_COMPOSITING_MODE for consistency with the previous one to disable AC.

[Carlos Alberto Lopez Perez]

Created attachment 271115 [details]
Patch

[Carlos Alberto Lopez Perez]

(In reply to comment #0)
> So I'm proposing here to add another variable, lets name it
> WEBKIT_DISABLE_COMPOSITING_MODE for consistency with the previous one to
> disable AC.

I mean                            ^  for consistency with the previous one to force AC mode always on.

[Carlos Garcia Campos]

Comment on attachment 271115 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=271115&action=review

> Source/WebKit2/UIProcess/gtk/WebPreferencesGtk.cpp:50
> +    if (getenv("WEBKIT_DISABLE_COMPOSITING_MODE"))
> +        setAcceleratedCompositingEnabled(false);

Is this enough? We are enabling AC unconditionally in DrawingAreaImpl::setNativeSurfaceHandleForCompositing(), but only when m_layerTreeHost has been created. I guess we would never enter AC mode if the setting is disabled in first place.

[Carlos Alberto Lopez Perez]

(In reply to comment #3)
> Comment on attachment 271115 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=271115&action=review
> 
> > Source/WebKit2/UIProcess/gtk/WebPreferencesGtk.cpp:50
> > +    if (getenv("WEBKIT_DISABLE_COMPOSITING_MODE"))
> > +        setAcceleratedCompositingEnabled(false);
> 
> Is this enough? We are enabling AC unconditionally in
> DrawingAreaImpl::setNativeSurfaceHandleForCompositing(), but only when
> m_layerTreeHost has been created. I guess we would never enter AC mode if
> the setting is disabled in first place.

Yes, my tests indicate it is.

For example, if I load poster circle I see a 2D animation instead of the 3D tube.

[WebKit Commit Bot]

Comment on attachment 271115 [details]
Patch

Clearing flags on attachment: 271115

Committed r196467: <http://trac.webkit.org/changeset/196467>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.