[Interest] Qt5/OMAP4/EGLFS: Strange animation behaviour

Stephan Kanthak stylon at gmx.de
Mon Nov 19 22:43:12 CET 2012

Hi all,

as promised some feedback on this matter...

On 11/16/2012 07:37 AM, Stephan Kanthak wrote:
>> Are you doing "export QML_FORCE_THREADED_RENDERER=1"? Because afaik
>> without that you won't get the threaded renderer. Most issues I've seen
>> with animations have been due to not using the threaded renderer.
Just "export QML_FORCE_THREADED_RENDERER=1" subjectively works best for 
me so far. I still do see tearing all over, so there's definitely no 
waiting for VSYNC, either in Qt5/EGLFS or the TI driver, but animations 
are smooth.

>> You might also want to try the customcontext renderer from
>> ssh://codereview.qt-project.org:29418/playground/scenegraph.git
>> After building and doing make install there you should be able to use it
>> by doing "export QMLSCENE_DEVICE=customcontext" or running with
>> --device=customcontext
I tried this code, too, although I had some problems adding Animators 
objects at the right spot in my QML files. It finally seems to work for 
me once Animations + animated objects are both from Animators. However, 
the result is not much better than with just "export 
QML_FORCE_THREADED_RENDERER=1". Tearing is even more obvious as the 
buffer swapping then seems to happen right in the middle of an animated 
texture covering the lower 50% of the display.

>> If it's a timing issue you might also try
After setting this, animations are a bit quicker, but smoothness also 
wasn't better than with just "export QML_FORCE_THREADED_RENDERER=1".

So, overall my remaining problem seems to be that buffers are not 
swapped with VSYNC. Any idea wether this is due to Qt5/EGLFS or rather 
the TI driver?


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