Bug 28692

Summary: poor performance in canvas demo
Product: WebKit Reporter: Eric Seidel (no email) <eric>
Component: ImagesAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: deanm, hyatt, krit, mdelaney7, oliver, psolanki
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: PC   
OS: OS X 10.5   
URL: http://tulrich.com/geekstuff/canvas/perspective.html
Bug Depends on: 28693    
Bug Blocks:    
Attachments:
Description Flags
shark sample of page rendering none

Description Eric Seidel (no email) 2009-08-24 16:29:14 PDT
Created attachment 38506 [details]
shark sample of page rendering

poor performance in canvas demo

http://tulrich.com/geekstuff/canvas/perspective.html

I profiled it in Shark and we're spending all our time in:
    CGContextDrawImage(context, adjustedDestRect, image);
under BitmapImage::draw in ImageCG.cpp

The demo looks fine in Chromium Windows/Linux (which uses Skia) and poor in Chromium Mac and Safari.  I'm not sure if this is a CG bug, a WebKit bug in how we're calling CG, a bug in Skia which makes their rendering "incorrectly" fast, or what.

CCing hyatt and Oliver due to their historical interest in this type of bug.  Feel free to remove yourselves if you're not in fact interested here.
Comment 1 Dirk Schulze 2009-08-26 01:22:05 PDT
It's smooth with the standard properties on cairo too, but gets realy slow with maximum details (like in Chromium). So no skia bug i guess.