Function fermium::SDL_JoystickGetBall

pub unsafe extern "C" fn SDL_JoystickGetBall(
    joystick: *mut SDL_Joystick, 
    ball: c_int, 
    dx: *mut c_int, 
    dy: *mut c_int
) -> c_int

Get the ball axis change since the last poll.

\return 0, or -1 if you passed it invalid parameters.

The ball indices start at index 0.