NAME

       SDL_JoyBallEvent - Joystick trackball motion event structure

STRUCTURE DEFINITION

       typedef struct{
         Uint8 type;
         Uint8 which;
         Uint8 ball;
         Sint16 xrel, yrel;
       } SDL_JoyBallEvent;

STRUCTURE DATA

       type                SDL_JOYBALLMOTION

       which               Joystick device index

       ball                Joystick trackball index

       xrel, yrel          The relative motion in the X/Y direction

DESCRIPTION

       SDL_JoyBallEvent  is  a  member  of  the SDL_Event union and is used when an event of type
       SDL_JOYBALLMOTION is reported.

       A SDL_JOYBALLMOTION event occurs when a user moves a trackball on the joystick. The  field
       which  is  the  index of the joystick that reported the event and ball is the index of the
       trackball (for a more detailed explaination see the  Joystick  section).  Trackballs  only
       return  relative  motion,  this  is  the  change in position on the ball since it was last
       polled (last cycle of the event loop) and it is stored in xrel and yrel.

SEE ALSO

       SDL_Event, Joystick Functions, SDL_JoystickEventState, SDL_JoystickGetBall