1 .TH "SDL_JoystickGetBall" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" 

     2 .SH "NAME"

     3 SDL_JoystickGetBall \- Get relative trackball motion

     4 .SH "SYNOPSIS"

     5 .PP

     6 \fB#include "SDL\&.h"

     7 .sp

     8 \fBint \fBSDL_JoystickGetBall\fP\fR(\fBSDL_Joystick *joystick, int ball, int *dx, int *dy\fR);

     9 .SH "DESCRIPTION"

    10 .PP

    11 Get the \fBball\fR axis change\&.

    12 .PP

    13 Trackballs can only return relative motion since the last call to \fBSDL_JoystickGetBall\fP, these motion deltas a placed into \fBdx\fR and \fBdy\fR\&.

    14 .SH "RETURN VALUE"

    15 .PP

    16 Returns \fB0\fR on success or \fB-1\fR on failure

    17 .SH "EXAMPLES"

    18 .PP

    19 .PP

    20 .nf

    21 \f(CWint delta_x, delta_y;

    22 SDL_Joystick *joy;

    23 \&.

    24 \&.

    25 \&.

    26 SDL_JoystickUpdate();

    27 if(SDL_JoystickGetBall(joy, 0, &delta_x, &delta_y)==-1)

    28   printf("TrackBall Read Error!

    29 ");

    30 printf("Trackball Delta- X:%d, Y:%d

    31 ", delta_x, delta_y);\fR

    32 .fi

    33 .PP

    34 .SH "SEE ALSO"

    35 .PP

    36 \fI\fBSDL_JoystickNumBalls\fP\fR

    37 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00