Bug 506877

Summary: Quake II RTX overly bright in HDR
Product: [Plasma] kwin Reporter: calvin <calvinatorzcraft>
Component: colour-managementAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED UPSTREAM    
Severity: normal CC: xaver.hugl
Priority: NOR    
Version First Reported In: 6.4.2   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description calvin 2025-07-10 17:53:45 UTC 
SUMMARY
Similarly to scrgb Windows games with proton, Quake II RTX (a native linux application) in HDR appears overly bright compared to when using VK_hdr_layer or gamescope.

STEPS TO REPRODUCE
1. Download Quake II RTX off steam
2. Launch game with SDL_VIDEODRIVER=wayland %command% steam launch options
3. Enable HDR in game settings, set ui brightness to 200 to match SDR brightness

OBSERVED RESULT
UI Is much brighter than HDR off, game brightness extreme and highlights blown out

EXPECTED RESULT
UI Is the same brightness as HDR off, game brightness normal and highlights bright but distinguishable

SOFTWARE/OS VERSIONS
Linux: Arch Linux Latest
KDE Plasma Version: 6.4.2
KDE Frameworks Version: 6.15.0
Qt Version: 6.9.1

ADDITIONAL INFORMATION
Brightness compared against https://github.com/Zamundaaa/VK_hdr_layer, game launched with ENABLE_HDR_WSI=1 SDL_VIDEODRIVER=wayland %command%