Bug 131303

Summary: [GTK] canvas-composite-*-alpha.html tests failing since added
Product: WebKit Reporter: Sergio Villar Senin <svillar>
Component: CanvasAssignee: Nobody <webkit-unassigned>
Status: RESOLVED FIXED    
Severity: Normal CC: krit
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: Unspecified   
OS: Unspecified   
Bug Depends on: 79659    
Bug Blocks:    
Attachments:
Description Flags
Stroke compositing test
none
WebKitGTK stroke compositing test none

Description Sergio Villar Senin 2014-04-07 09:27:55 PDT
Both
* fast/canvas/canvas-composite-stroke-alpha.html
* fast/canvas/canvas-composite-text-alpha.html

are failing on GTK bots since added.
Comment 1 Dirk Schulze 2014-04-07 22:15:01 PDT
I can not build Cairo graphics port. In the past, beginTransparencyLayer created a new paint mask for GraphicsContextCairo. This was basically doing what CG does: creating a new layer that is composited with an alpha value afterwards. I wonder why this would not work anymore. Could you send screenshots of https://developer.mozilla.org/samples/canvas-tutorial/6_1_canvas_composite.html please?
Comment 2 Dirk Schulze 2014-04-08 00:01:13 PDT
Created attachment 228811 [details]
Stroke compositing test

Sorry, please upload an image for the attached test.
Comment 3 Jae Hyun Park 2014-04-08 00:22:40 PDT
Created attachment 228816 [details]
WebKitGTK stroke compositing test

This is the screenshot of stroke compositing test that ran on MiniBrowser of WebKitGTK+.
Comment 4 Dirk Schulze 2014-04-08 06:31:45 PDT
(In reply to comment #3)
> Created an attachment (id=228816) [details]
> WebKitGTK stroke compositing test
> 
> This is the screenshot of stroke compositing test that ran on MiniBrowser of WebKitGTK+.

It looks like destination-atop and source-out improved by the patch. Source-in and destination-in are incorrect. Since the other cases work, it seems more like a bug in Cairo graphics.
Comment 5 Dirk Schulze 2014-04-14 09:22:56 PDT
fixed by the dependent bug.