mirror of
https://github.com/libsdl-org/SDL.git
synced 2025-09-05 19:08:12 +00:00
ab916a959e
Wayland has a myriad of unresolved problems regarding surface suspension blocking forever in QueuePresent/SwapBuffers when occludedand the FIFO (vsync) implementation being fundamentally broken leading to reduced GPU-bound performance and 'barcoding' frametimes due to swapchain starvation. There are two protocols used to solve these two problems together -- fifo-v1 and commit-timing-v1, which implement the commit queue on the compositor side, and a timestamp that frames are intended to be displayed for/discarded respectfully. To avoid severe performance regressions for developers targeting SDL3, only pick Wayland as the default backend when these two protocols are supported -- otherwise fallback to X11/XWayland. We do this by having two VideoBootStraps, one which is tests the preferred case, "wayland_preferred" (ie. if fifo-v1 + commit-timing-v1 are available init time), and the fallback, which is just "wayland", the same name as before, which does no such tests. Thus, forcing with SDL_VIDEO_DRIVER=wayland will go onto the fallback option, and pick Wayland always, as usual, so there is no behaviour change. In the case that X11/XWayland is not available (ie. no DISPLAY), we will still fallback to using Wayland without these protocols available. Signed-off-by: Joshua Ashton <joshua@froggi.es>
Simple DirectMedia Layer (SDL) Version 3.0
Simple DirectMedia Layer is a cross-platform development library designed to provide low level access to audio, keyboard, mouse, joystick, and graphics hardware. It is used by video playback software, emulators, and popular games including Valve's award winning catalog and many Humble Bundle games.
More extensive documentation is available in the docs directory, starting with README.md. If you are migrating to SDL 3.0 from SDL 2.0, the changes are extensively documented in README-migration.md.
Enjoy!
Sam Lantinga (slouken@libsdl.org)