Manual Pages for UNIX Operating System command usage for man SDL_JoystickGetBall

SDL API Reference                          SDL_JoystickGetBall(3)



NAME
     SDL_JoystickGetBall - Get relative trackball motion

SYNOPSIS
     #include "SDL.h"

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

DESCRIPTION
     Get the ball axis change.

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

RETURN VALUE
     Returns 0 on success or -1 on failure

EXAMPLES
     int delta_x, delta_y;
     SDL_Joystick *joy;
     .
     .
     .
     SDL_JoystickUpdate();
     if(SDL_JoystickGetBall(joy, 0, &delta_x, &delta_y)==-1)
       printf("TrackBall Read Error!
     ");
     printf("Trackball Delta- X:%d, Y:%d
     ", delta_x, delta_y);

SEE ALSO
     SDL_JoystickNumBalls





















SDL            Last change: Tue 11 Sep 2001, 23:00              1