Bug 69866

Summary:

Chromium needs support for border radius clipping

Product:

WebKit

Reporter:

Tom Hudson <tomhudson>

Component:

New Bugs

Assignee:

Tom Hudson <tomhudson>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

7raivis, dstockwell, eric.carlson, eric, feature-media-reviews, mikelawther, noel.gordon, peter, reed, senorblanco, webkit.review.bot, yurys

Priority:

Version:

528+ (Nightly build)

Hardware:

Unspecified

OS:

Unspecified

Attachments:

Description	Flags
Patch	none

Tom Hudson

Reported 2011-10-11 13:48:43 PDT

The speed of the current soft clipping implementation in Chromium is insufficient to support border radius clipping in websites that make heavy use of layers (https://bugs.webkit.org/show_bug.cgi?id=68733). Border radius clipping is turned off for chromium in https://bugs.webkit.org/show_bug.cgi?id=69844, but it needs to be reenabled - either when the fast path in #68733 is shown to work well enough in practice, or when the Windows/GDI/Skia issues blocking soft clipping for Chromium are resolved.

Attachments
Patch (797.20 KB, patch) 2012-10-02 18:25 PDT, dstockwell	no flags	Details Formatted Diff Diff
View All Add attachment proposed patch, testcase, etc.

Tom Hudson

Comment 1 2011-11-11 05:20:54 PST

Status update: the first pass at anti-aliased clipping in Skia has landed and gets performance on targeted pages up to 10-15fps when we reenable border radius clipping; this is far better than it was when border radius clipping was disabled, but still a factor of two below our target. We're investigating.

Peter Beverloo

Comment 2 2012-02-23 04:11:38 PST

For reference: I just tried this with ToT Chromium and WebKit, unfortunately I'm still getting 80-100% CPU usage and only 15-20 fps on Twitter.

Tom Hudson

Comment 3 2012-02-23 13:47:26 PST

(In reply to comment #2) > For reference: I just tried this with ToT Chromium and WebKit, unfortunately I'm still getting 80-100% CPU usage and only 15-20 fps on Twitter. Actually, that's the pre-existing performance, and what we'll get after this bug is resolved. The Skia optimizations required to support WebKit's border radius clipping in Chromium have landed, and enabling that feature produces no significant difference in the frame rate or profile, but we're rendering wrong for one of the four layout tests (fast/clip/overflow-border-radius-composited). The Chromium CPU profile doesn't suggest any more obvious targets for microoptimzation in Skia; we're busy doing the direct work of clearing and blitting - further speedup for Twitter is likely going to take changing how much WebKit tries to draw.

dstockwell

Comment 4 2012-10-02 18:25:58 PDT

Created attachment 166792 [details] Patch

dstockwell

Comment 5 2012-10-02 18:44:32 PDT

The test noted above (fast/clip/overflow-border-radius-composited) is still failing, but there is a separate issue for this: http://webkit.org/b/68196 A number of media control tests have subtle differences due to their uses of border-radius, I've included rebaselines for linux and will update expectations for the other platforms after landing.

noel gordon

Comment 6 2012-10-02 18:53:24 PDT

LGTM. aisde: maybe file a bug about video-controls-rendering.html and it's use of scroll bars?

noel gordon

Comment 7 2012-10-02 19:03:01 PDT

Mr White: review please?

Stephen White

Comment 8 2012-10-03 07:25:26 PDT

This looks ok, but note that antialiased clipping is not (quite) implemented in the GPU path in Skia. That's probably not an issue right now, but I'd like to get a thumbs-up from reed@ and robertphillips@ before we turn this on.

Mike Reed

Comment 9 2012-10-03 07:49:31 PDT

aaclipping is used for all other soft-clip requests in PlatformContext, so I see no reason to not use it here (from skia's perspective).

Stephen White

Comment 10 2012-10-03 07:50:41 PDT

Comment on attachment 166792 [details] Patch Thanks. robertphillips@ gave me a thumbs-up offline, so r=me.

WebKit Review Bot

Comment 11 2012-10-03 19:17:39 PDT

Comment on attachment 166792 [details] Patch Clearing flags on attachment: 166792 Committed r130355: <http://trac.webkit.org/changeset/130355>

WebKit Review Bot

Comment 12 2012-10-03 19:17:43 PDT

All reviewed patches have been landed. Closing bug.