Open a joystick for use.
int device_index);SDL_Joystick* SDL_JoystickOpen(
|device_index||the index of the joystick to query|
Returns a joystick identifier or NULL if an error occurred; call SDL_GetError() for more information.
device_index argument refers to the N'th joystick presently recognized by SDL on the system. It is NOT the same as the instance ID used to identify the joystick in future events. See SDL_JoystickInstanceID() for more details about instance IDs.
The joystick subsystem must be initialized before a joystick can be opened for use.
This function is available since SDL 2.0.0.