A function pointer used for callbacks that watch the event queue.
\param userdata what was passed as userdata to SDL_SetEventFilter() or
SDL_AddEventWatch, etc.
\param event the event that triggered the callback.
\returns true to permit event to be added to the queue, and false to
disallow it. When used with SDL_AddEventWatch, the return value is
ignored.
\threadsafety SDL may call this callback at any time from any thread; the
application is responsible for locking resources the callback
touches that need to be protected.
\since This datatype is available since SDL 3.2.0.
A function pointer used for callbacks that watch the event queue.
\param userdata what was passed as userdata to SDL_SetEventFilter() or SDL_AddEventWatch, etc. \param event the event that triggered the callback. \returns true to permit event to be added to the queue, and false to disallow it. When used with SDL_AddEventWatch, the return value is ignored.
\threadsafety SDL may call this callback at any time from any thread; the application is responsible for locking resources the callback touches that need to be protected.
\since This datatype is available since SDL 3.2.0.
\sa SDL_SetEventFilter \sa SDL_AddEventWatch