Bug 110318 (antialiasing) - [cairo] Antialias is disabled when shapes are clipped and rotated
Summary: [cairo] Antialias is disabled when shapes are clipped and rotated
Status: UNCONFIRMED
Alias: antialiasing
Product: WebKit
Classification: Unclassified
Component: Layout and Rendering (show other bugs)
Version: 528+ (Nightly build)
Hardware: Other Linux
: P2 Normal
Assignee: Nobody
URL:
Keywords: Cairo, Regression
Depends on:
Blocks:
 
Reported: 2013-02-20 02:36 PST by Vitalii Shkibtan
Modified: 2023-06-13 16:16 PDT (History)
4 users (show)

See Also:

Attachments
Current rotation result (1.22 KB, application/xhtml+xml)
2013-02-20 02:36 PST, Vitalii Shkibtan 		no flags Details
screenshot of the current result (5.73 KB, image/png)
2013-02-20 02:44 PST, Vitalii Shkibtan 		no flags Details
Screenshot after reverting the set of changes 119242 (7.00 KB, image/png)
2013-02-20 03:05 PST, Vitalii Shkibtan 		no flags Details
View All Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this bug.
Description Vitalii Shkibtan 2013-02-20 02:36:15 PST 
Created attachment 189270 [details]
Current rotation result

Overview: 
Contour of shapes after clipping and rotating doesn't smooth

Steps to Reproduce:
Open the attached file test.xhtml

Actual Results:
Contour of shapes after clipping and rotating doesn't smooth

Expected Results:
Contour of shapes after clipping and rotating must be smooth

Build Date & Platform:
Build 2013-20-02 on Kubuntu 12.10 x64

Additional Information:
There are Bug 85483 in WebKit Bugzilla ([cairo] Pixel artifacts can be seen on reflections).
If I revert changes from this bug I can clip and rotate shapes with antialiasing.
Comment 1 Vitalii Shkibtan 2013-02-20 02:44:04 PST 
Created attachment 189272 [details]
screenshot of the current result
Comment 2 Vitalii Shkibtan 2013-02-20 03:05:22 PST 
Created attachment 189273 [details]
Screenshot after reverting the set of changes 119242
Comment 3 Dominik Röttsches (drott) 2013-02-20 05:23:10 PST 
Yes, that's pretty much what the patch did: Not using anti aliasing when clipping. 

I am opening your test case on Chrome here and it's not antialiased - so Skia backend at least does the same. On Opera and Safari these are antialiased. This would require some refactoring on GraphicsContext to actually get this right in both cases (i.e. your case here (if it's a bug), and the reflection case).