A structure that contains joystick trackball motion event information.
Uint32 |
type |
SDL_JOYBALLMOTION |
Uint32 |
timestamp |
timestamp of the event |
SDL_JoystickID |
which |
the instance id of the joystick that reported the event |
Uint8 |
ball |
the index of the trackball that changed |
Sint16 |
xrel |
the relative motion in the X direction |
Sint16 |
yrel |
the relative motion in the Y direction |
SDL_JoyBallEvent is a member of the SDL_Event union and is used when an event of type SDL_JOYBALLMOTION is reported. You would access it through the event's jball
field.
An SDL_JOYBALLMOTION event occurs when a user moves a trackball on the joystick.
Trackballs only return relative motion. This is the change in position of the ball since it was last polled (last cycle of the event loop).