.SH "SYNOPSIS"

.PP

\fB#include "SDL\&.h"

.sp

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

.SH "DESCRIPTION"

.PP

Get the \fBball\fR axis change\&.

.PP

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\&.

.SH "RETURN VALUE"

.PP

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

.SH "EXAMPLES"

.PP

.PP

.nf

\f(CWint 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);\fR

.fi

.PP

.SH "SEE ALSO"

.PP

\fI\fBSDL_JoystickNumBalls\fP\fR