[Webkit-unassigned] [Bug 50527] [Qt] Background image rendering is slow

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=50527





--- Comment #21 from Noam Rosenthal <noam.rosenthal at nokia.com>  2010-12-27 09:43:18 PST ---
(In reply to comment #20)
> Anyway it looks good and it passes the tests. No'am do you have any performance numbers? Any change of getting this into Qt?

Out of the 22 tests in fast/backgrounds/size, running on Mac with raster graphics system:

The average painting speed improvement is 50%

9 tests: improvement in performance of 50% or more.
3 tests: improvement of 25%-50%
8 tests: similar before/after numbers
3 tests: 25%-50% regression (see below for explanation).
No test shows a regression of more than 25%.

Those 3 tests that regressed are fast to render both before and after, but the extra rendering step to scale the tile does cause them to not be as fast - those 3 tests are of a large scaled background image that only repeats once or twice - in those cases the extra rendering step just causes overhead. However, I doubt those situations would be very slow in real circumstances, unlike the use case of repeating small images multiple times, which is sometimes improved by 80%.

-- 
Configure bugmail: https://bugs.webkit.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.