SUMMARY Some games that use scRGB (VK_COLOR_SPACE_EXTENDED_SRGB_LINEAR_EXT) in HDR are limited to SDR luminance levels when fullscreen, causing a blown out image. However, when the game is not fullscreen (using the Meta+F shortcut) HDR works normally. It also works if the game fully covers the screen (auto hide panel, no borders) but is not fullscreen. STEPS TO REPRODUCE 1. Play a game that uses scRGB in HDR (e.g. Assassin's Creed Odyssey, Cyberpunk with the HDR Mode set to scRGB, Star Wars Jedi: Fallen Order). 2. Ensure the game is fullscreen. 3. Enable HDR in the game's settings. OBSERVED RESULT Highlights are clipped as if limited to SDR levels. EXPECTED RESULT HDR works normally. SOFTWARE/OS VERSIONS KDE Plasma Version: 6.2.91 KDE Frameworks Version: 6.10 Qt Version: 6.9.0beta2 ADDITIONAL INFORMATION - The issue also occurs with KWin 6.2.5. - The issue occurs with both gamescope and native wayland. - Hot Wheels Unleashed is an HDR scRGB game but does not exhibit this issue.
A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/7058
That fixes the bug. Thanks!
Git commit 62196bf736feb6814661dd8154fa1b46c48eb2db by Xaver Hugl. Committed on 25/01/2025 at 02:01. Pushed by zamundaaa into branch 'master'. backends/drm: don't use LUTs for scaling anything outside of the [0; 1] range They clamp input and output values to that range, so they're not usable for that purpose. M +3 -0 src/backends/drm/drm_colorop.cpp https://invent.kde.org/plasma/kwin/-/commit/62196bf736feb6814661dd8154fa1b46c48eb2db
A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/7060
Git commit 888deff8c65dd46bf6df9d00fb8022bc1779f793 by Xaver Hugl. Committed on 25/01/2025 at 12:50. Pushed by zamundaaa into branch 'Plasma/6.3'. backends/drm: don't use LUTs for scaling anything outside of the [0; 1] range They clamp input and output values to that range, so they're not usable for that purpose. (cherry picked from commit 62196bf736feb6814661dd8154fa1b46c48eb2db) Co-authored-by: Xaver Hugl <xaver.hugl@gmail.com> M +3 -0 src/backends/drm/drm_colorop.cpp https://invent.kde.org/plasma/kwin/-/commit/888deff8c65dd46bf6df9d00fb8022bc1779f793
I guess it's a different bug but that second MR fixes the overly bright look of scRGB games. I wasn't experiencing it before because I using a patch to restore the pass through behavior of 6.2.
Git commit fb695ba708fa0d2f96118a548d59ee6805620743 by Xaver Hugl. Committed on 25/01/2025 at 12:58. Pushed by zamundaaa into branch 'master'. wayland/frog color management: use a reference luminance of 203 nits for scRGB 80 nits is correct, but Windows doesn't do correct, and with the frog protocol we know we're getting the image from a game using Windows scRGB. 203 nits is what we use for PQ, so this will ensure that PQ and scRGB modes in games look roughly the same. M +16 -1 src/wayland/frog_colormanagement_v1.cpp https://invent.kde.org/plasma/kwin/-/commit/fb695ba708fa0d2f96118a548d59ee6805620743
A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/7062
Git commit 388436ea64c57106d9027f29354a445aa4f43c00 by Xaver Hugl. Committed on 26/01/2025 at 19:15. Pushed by zamundaaa into branch 'Plasma/6.3'. wayland/frog color management: use a reference luminance of 203 nits for scRGB 80 nits is correct, but Windows doesn't do correct, and with the frog protocol we know we're getting the image from a game using Windows scRGB. 203 nits is what we use for PQ, so this will ensure that PQ and scRGB modes in games look roughly the same. (cherry picked from commit fb695ba708fa0d2f96118a548d59ee6805620743) Co-authored-by: Xaver Hugl <xaver.hugl@gmail.com> M +16 -1 src/wayland/frog_colormanagement_v1.cpp https://invent.kde.org/plasma/kwin/-/commit/388436ea64c57106d9027f29354a445aa4f43c00
This issue has been reintroduced with https://invent.kde.org/plasma/kwin/-/commit/5453662f9cd4816e4b046beb0c7df5a676a3df7c, but only in two of the games I tested: AC Odyssey and Cyberpunk. It also also broke scanout in PQ apps.