Bug 148473

Summary: [GTK] Disable ACCELERATED_2D_CANVAS by default
Product: WebKit Reporter: Michael Catanzaro <mcatanzaro>
Component: WebKitGTKAssignee: Michael Catanzaro <mcatanzaro>
Status: RESOLVED FIXED    
Severity: Enhancement CC: cgarcia, clopez, commit-queue, gustavo, mcatanzaro, mrobinson
Priority: P2    
Version: Other   
Hardware: PC   
OS: Linux   
Attachments:
Description Flags
Patch none

Description Michael Catanzaro 2015-08-26 06:35:05 PDT 
Currently ACCELERATED_2D_CANVAS is enabled by default on most systems (which have CairoGL) but not on Debian (which does not). We've known this was problematic for a while, since it means we have two different sets of distro-dependent bugs, but never decided whether that outweighed the benefits of CarioGL or not. I'm making the call now: it's more important to have the same bugs everywhere. We can turn this on again for other distros when we're ready to turn it on for Debian.
Comment 1 Martin Robinson 2015-08-26 06:40:46 PDT 
Okay. Sounds reasonable to me.
Comment 2 Michael Catanzaro 2015-08-26 06:45:22 PDT 
Created attachment 259947 [details]
Patch
Comment 3 WebKit Commit Bot 2015-08-26 11:46:20 PDT 
Comment on attachment 259947 [details]
Patch

Clearing flags on attachment: 259947

Committed r188973: <http://trac.webkit.org/changeset/188973>
Comment 4 WebKit Commit Bot 2015-08-26 11:46:23 PDT 
All reviewed patches have been landed.  Closing bug.
Comment 5 Carlos Alberto Lopez Perez 2015-09-14 06:16:51 PDT 
The script Tools/Scripts/build-webkit is still enabling this feature by default for the GTK port:

$ grep -C1 accelerated2DCanvasSupport Tools/Scripts/webkitperl/FeatureList.pm
    { option => "accelerated-2d-canvas", desc => "Toggle Accelerated 2D Canvas support",
      define => "ENABLE_ACCELERATED_2D_CANVAS", default => isGtk(), value => \$accelerated2DCanvasSupport },


This means that both the developers and the bots are building and testing with this feature enabled.

Should we do anything about that?
Comment 6 Michael Catanzaro 2015-09-14 06:55:04 PDT 
It's expected that build-webkit often enables experimental options that are disabled by default for end users.

Advantage of having enabled: If we disable it, there will be zero testing of the feature, and it could break.

Disadvantage of having enabled: It could make it impossible to reproduce bugs with a development build.

But ACCELERATED_2D_CANVAS is a public (non-experimental) option, which argues in favor of it being enabled for developers and tested. Maybe it should be private, though.