SDL_JoystickUpdate (3) - Linux Manuals
SDL_JoystickUpdate: Updates the state of all joysticks
NAME
SDL_JoystickUpdate - Updates the state of all joysticksSYNOPSIS
#include "SDL.h"
void SDL_JoystickUpdate(void);
DESCRIPTION
Updates the state(position, buttons, etc.) of all open joysticks. If joystick events have been enabled with SDL_JoystickEventState then this is called automatically in the event loop.
SEE ALSO
SDL_JoystickEventState