Get the ball axis change since the last poll.
Defined in <SDL3/SDL_joystick.h>
bool SDL_GetJoystickBall(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. |
(bool) Returns true on success or false on failure; call SDL_GetError() for more information.
Trackballs can only return relative motion since the last call to SDL_GetJoystickBall(), these motion deltas are placed into dx and dy.
Most joysticks do not have trackballs.
It is safe to call this function from any thread.
This function is available since SDL 3.2.0.