You can set an environment variable to the name of the driver you want to use. The drivers available depend on the platform and SDL compile-time options.
SDL_VIDEO_DRIVER. Some possible options are "x11", "wayland", "cocoa", etc.SDL_AUDIO_DRIVER. Some possible options are "pipewire", "pulseaudio", "directsound", "wasapi", "cocoa", etc.SDL_RENDER_DRIVER. Some possible options are "opengl", "direct3d", "software".Note that in SDL 1.2 and SDL2, there was one less underscore: SDL_VIDEODRIVER. This legacy variable name is ignored in SDL3!
While an application could force this with SDL_SetHint(), we strongly encourage you not to do this; let SDL choose the best option, and let the user use the environment variable if they have specific needs; applications usually shouldn't get involved in this choice.
(The exception is if the program needs to do something specific with a windowing system: for example, it needs to force the X11 driver because it is using a library that needs to talk to an X server. But in these cases, we'd also strongly encourage you to consider that as a bug to be fixed urgently.)
A complete list is available in SDL_hints.h. These can be set programmatically with SDL_SetHint, or specified as enviroment variables by the end-user.
Many applications using SDL are games or screensavers or media players where the user is either watching something for an extended period of time or using joystick input which generally does not prevent the screensaver from kicking on.
You can disable this behavior by setting the environment variable: SDL_VIDEO_ALLOW_SCREENSAVER=1
This can be set globally for the user or on a per-application basis in code.
Programmatically, the function SDL_EnableScreenSaver can be used; this might make sense for some programs to universally enable the screensaver, or toggle it to disabled only during media playback, etc.