Hi, Some apps like fullscreen 3D games don't really benefit from being redirected by a compositor but suffer a performance hit when being run under a compositor. To deal with that compositors do either (optionally) unredirect fullscreen windows, disable compositing completely when a fullscreen app is running, try to only redirect specific fullscreen windows or simply do not do anything at all and just pay the price.
Neither of the above is really ideal as unredirecting the "wrong" window does have bad side effects like possible flicker when opening popup windows or tearing due to no longer being vsynced by the compositor. The compositor can not really know beforehand what the app is going to do and whether it benefits from being unredirected at all, the app on the other hand should have enough information to make this decision. So I propose a new _NET_WM hint, that when set tells the compositor "I do benefit from being unredirected and I promise to not do stupid stuff while being unredirected". Of course that should be just be a hint i.e the compositor is free to ignore it and just redirect the app anyway when it needs to for some reason (like recording video using gnome-shell's screencast recorder). We would also need a hint to do the opposite i.e for apps to explicitly say "I don't want to be unredirected". The KDE people already implemented an opt-in implementation https://projects.kde.org/projects/kde/kdelibs/repository/revisions/7cd28e48adfdc1fca2caf9c8453c209ddf0d5452 We should standardize this so that apps can work with that across multiple WMs. I do plan to add support to mutter once we standardized this. Thanks, Adel _______________________________________________ wm-spec-list mailing list wm-spec-list@gnome.org http://mail.gnome.org/mailman/listinfo/wm-spec-list
