Bug 409997

Summary: Very slow performance
Product: [Plasma] Oxygen Reporter: BRULE Herman <alpha_one_x86>
Component: styleAssignee: Unassigned bugs mailing-list <unassigned-bugs>
Status: RESOLVED NOT A BUG    
Severity: normal    
Priority: NOR    
Version: 5.16.3   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description BRULE Herman 2019-07-19 13:06:22 UTC 
SUMMARY


STEPS TO REPRODUCE
1. compile and start https://github.com/alphaonex86/CatchChallenger/tree/master/tools/animatedbackground
2. look the CPU used with oxygen theme
3. look the CPU with other theme

OBSERVED RESULT
Oxygen use 15% of CPU

EXPECTED RESULT
Other theme use only 2% of CPU

Can you fix the performance please?
Comment 1 Christoph Feck 2019-08-05 20:21:55 UTC 
Oxygen uses background gradients, which unfortunately are much slower to render compared to a flat background.
Comment 2 BRULE Herman 2019-08-05 21:34:04 UTC 
I use too background gradient, via QPainter and no performance problem.
Comment 3 Christoph Feck 2019-08-05 22:29:51 UTC 
A radial gradient? Linear gradients are much faster.
Comment 4 BRULE Herman 2019-08-06 00:22:42 UTC 
Then you can QPainter on QPixmap to cache it, and update cache if the resolution change else just redraw the QPixmap.