[Webkit-unassigned] [Bug 30211] [Qt] Consider prefering QImage* over QPixmap* as NativeImagePtr

bugzilla-daemon at webkit.org bugzilla-daemon at webkit.org
Mon Oct 12 22:45:39 PDT 2009


--- Comment #3 from Holger Freyther <zecke at selfish.org>  2009-10-12 22:45:39 PDT ---
(In reply to comment #2)
> Hmm, is the goal to distinguish between a paintengine that _can_ draw
> transformed pixmaps efficiently (i.e. openvg or opengl) and a paintengine that
> fails to do so (x11) ?
> If yes, I guess we could try to use the paint engine's feature flags to
> determine this at run-time.

This would be one idea, in general this is about collecting ideas and then
measuring. My impression is that blindly converting to a QPixmap even if it is
only painted once will not be a win so we should have a better strategy.

Some more background information. When looking at the Szeged Image test site we
load big images and scale them down to 100x100. So what happens there is we
load the big QImage, convert it to a bigger QPixmap (XImage..) and upload,
convert it back to a bigger QImage, paint.

After having instrumented the BitmapImage::drawImage routine on the test
content I see that the above is the minority. From my instrumentation something
like 10% of draw operations are scaling images.

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

More information about the webkit-unassigned mailing list