Bug 466076

Summary: Spectacle lagging in a mixed DPI setup
Product: [Applications] Spectacle Reporter: Tarballwalf <unzippedtarball>
Component: GeneralAssignee: Boudhayan Gupta <me>
Status: RESOLVED FIXED    
Severity: minor CC: kde, nate
Priority: NOR    
Version First Reported In: 22.12.2   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In: 23.04
Sentry Crash Report:
Attachments: reprezentation of the poor perfromance, along with the observed temporary fix

Description Tarballwalf 2023-02-19 12:22:32 UTC
Created attachment 156483 [details]
reprezentation of the poor perfromance, along with the observed temporary fix

SUMMARY
Trying to take a region capture while having a mixed DPI display setup results in spectacle servery lagging/dropping performance. This issue seems to happen even if the display has already been connected (not docking the laptop resulting in a "new" display to be attached)


STEPS TO REPRODUCE
1. Have a mixed DPI setup (100% and 120% in my case)
2. Try taking a region capture

OBSERVED RESULT
Selection starts lagging

EXPECTED RESULT
Should be buttery smooth, just like on one monitor

SOFTWARE/OS VERSIONS
Linux/KDE Plasma:  Manjaro KDE (Unstable branch)
(available in About System)
KDE Plasma Version: 5.27.0
KDE Frameworks Version: 5.103.0
Qt Version: 5.15.8

ADDITIONAL INFORMATION
Running on Plasma Wayland session
Going into settings and disabling and re-enabling the scaled display seems to temporarily fix this issue
Comment 1 Nate Graham 2023-02-21 23:52:51 UTC
This is fixed in the upcoming 23.04 release which re-rwore the rectangular region UI to be radically faster and more performant.