SDL_JoystickGetBall

Get the ball axis change since the last poll.

Header File

int SDL_JoystickGetBall(SDL_Joystick *joystick,
                        int ball, int *dx, int *dy);

SDL_Joystick *	joystick	the SDL_Joystick to query.
int	ball	the ball index to query; ball indices start at index 0.
int *	dx	stores the difference in the x axis position since the last poll.
int *	dy	stores the difference in the y axis position since the last poll.

(int) Returns 0 on success or a negative error code on failure; call SDL_GetError() for more information.

Trackballs can only return relative motion since the last call to SDL_JoystickGetBall(), these motion deltas are placed into dx and dy.

Most joysticks do not have trackballs.

This function is available since SDL 2.0.0.