Bug 22746

Summary: Enable antialiasing for border drawing, when transformed
Product: WebKit Reporter: Simon Fraser (smfr) <simon.fraser>
Component: Layout and RenderingAssignee: Simon Fraser (smfr) <simon.fraser>
Status: RESOLVED FIXED    
Severity: Normal CC: hyatt, mitz, simon.fraser
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: Macintosh   
OS: OS X 10.5   
Bug Depends on: 58761    
Bug Blocks:    
Attachments:
Description Flags
Screenshot: current state on the left, with antialiasing on the right.
none
Borders with alpha none

Description Simon Fraser (smfr) 2008-12-08 17:21:06 PST
Rotated tables look awful because the border is drawn without antialiasing (see screenshot). We should turn on antialiasing, but why was it turned off in the first place?
Comment 1 Simon Fraser (smfr) 2008-12-08 17:22:39 PST
Created attachment 25864 [details]
Screenshot: current state on the left, with antialiasing on the right.
Comment 2 mitz 2008-12-08 17:31:49 PST
Comment on attachment 25864 [details]
Screenshot: current state on the left, with antialiasing on the right.

Why is there a crack in the bottom-right corner in the non-rotated case? It looks like a serious problem.
Comment 3 Simon Fraser (smfr) 2008-12-08 19:11:36 PST
Yeah, that could be an issue.
Comment 4 Simon Fraser (smfr) 2008-12-09 10:13:32 PST
Created attachment 25890 [details]
Borders with alpha

It would also be nice to fix the issues when using rgba() colors as borders (see screenshot).
Comment 5 mitz 2008-12-09 10:18:20 PST
Comment on attachment 25890 [details]
Borders with alpha

Bug 21835.
Comment 6 Simon Fraser (smfr) 2008-12-09 17:14:09 PST
Hyatt says that we can't just turn on AA for borders; web authors rely on the per-pixel rendering. We may be able to turn on AA if the element is transformed, though.
Comment 7 mitz 2008-12-17 20:15:01 PST
See also bug 19421.
Comment 8 Simon Fraser (smfr) 2010-07-16 13:02:34 PDT
We think this makes http://unevengoogle.com/ look bad.
Comment 9 Simon Fraser (smfr) 2010-08-18 10:51:16 PDT
Borders used for "pixel art": http://www.infimum.dk/HTML/slantinfo.html
Comment 10 Simon Fraser (smfr) 2011-04-17 08:55:28 PDT
Another reason to do this is that we draw solid borders with rects (antialiased), and groove/inset/outset borders with polygons (non antia-aliased), so if you change the border style, you go between OK and crappy rendering.
Comment 11 Simon Fraser (smfr) 2011-04-19 11:46:36 PDT
http://trac.webkit.org/changeset/84273