/* 
 *  call-seq:
 *    balls  ->  Integer
 *
 *  Returns the number of trackballs featured on the Joystick. A trackball is
 *  usually a small sphere which can be rotated in-place in any direction,
 *  registering relative movement along two axes. See alse #ball_state().
 */
VALUE rbgm_joystick_numballs( VALUE self )
{
        SDL_Joystick *joy;
        Data_Get_Struct(self,SDL_Joystick,joy);
        return INT2FIX(SDL_JoystickNumBalls(joy));
}