.TH "SDL_JoystickGetBall" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" .SH "NAME"SDL_JoystickGetBall\- Get relative trackball motion.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".PPGet the \fBball\fR axis change\&..PPTrackballs 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".PPReturns \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...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00