Created attachment 181394 [details] kscreen-doctor -o SUMMARY Wayland HDR still using 80cd/m² for Windows scRGB instead of 203cd/m² reference luminance. Running same games with same calibration through Gamescope has correct reference target of 203 regardless of color space STEPS TO REPRODUCE 1. Set 1000 nit peak and 203 target brightness with HDR calibration tool on desktop 2. Launch any scRGB HDR game using wayland (Control, Cyberpunk 2077) 3. Adjust in game calibration accordingly 4. See that 203 desktop brightness is clipping on brightest light sources 5. Adjust desktop brightness to 80 nits 6. Verify that highlights in game are no longer clipping. OBSERVED RESULT In game highlights are clipping when desktop brightness is set to 203 In game highlights are no longer clipping when desktop brightness is set to 80 EXPECTED RESULT Correctly calibrated in game highlights not clipping when desktop brightness is set to 203 SOFTWARE/OS VERSIONS Linux/KDE Plasma: Arch Linux 6.15.0-rc6-273-tkg-eevdf KDE Plasma Version: 6.3.90 KDE Frameworks Version: 6.14.0 Qt Version: 6.9.0 ADDITIONAL INFORMATION Proton version used to test Wayland https://github.com/GloriousEggroll/proton-ge-custom/releases/tag/GE-Proton10-1 Gamescope version used to verify findings gamescope-git-3.16.8.r1.g1f121c6e-1 Steam launch options with wayland PROTON_ENABLE_WAYLAND=1 PROTON_ENABLE_HDR=1 mangohud %command% Steam launch options with gamescope DXVK_HDR=1 gamescope -f -W 2560 -H 1440 -S integer -F nearest --hdr-enabled --hdr-sdr-content-nits 1000 --force-grab-cursor --rt --mangoapp -- %command%
Just discovered that using these options results in correct reference of 203cd/m² PROTON_ENABLE_WAYLAND=1 PROTON_ENABLE_HDR=1 mangohud %command% And using these results in incorrect reference of 80cd/m² DISPLAY= DXVK_HDR=1 mangohud %command% --launcher-skip
Proton doesn't use Windows scRGB, gamescope is currently its only user.