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1 .TH "SDL_JoystickGetBall" "3" "Mon 12 Mar 2001, 01:03" "SDL" "SDL API Reference"
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2 .SH "NAME"
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3 SDL_JoystickGetBall\- Get relative trackball motion
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4 .SH "SYNOPSIS"
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5 .PP
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6 \fB#include "SDL\&.h"
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7 .sp
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8 \fBint \fBSDL_JoystickGetBall\fP\fR(\fBSDL_Joystick *joystick, int ball, int *dx, int *dy\fR);
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9 .SH "DESCRIPTION"
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10 .PP
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11 Get the \fBball\fR axis change\&.
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12 .PP
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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\&.
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14 .SH "RETURN VALUE"
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15 .PP
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16 Returns \fB0\fR on success or \fB-1\fR on failure
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17 .SH "EXAMPLES"
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18 .PP
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19 .PP
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20 .nf
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21 \f(CWint delta_x, delta_y;
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22 SDL_Joystick *joy;
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23 \&.
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24 \&.
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25 \&.
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26 SDL_JoystickUpdate();
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27 if(SDL_JoystickGetBall(joy, 0, &delta_x, &delta_y)==-1)
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28 printf("TrackBall Read Error!
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29 ");
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30 printf("Trackball Delta- X:%d, Y:%d
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31 ", delta_x, delta_y);\fR
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32 .fi
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33 .PP
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34 .SH "SEE ALSO"
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35 .PP
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36 \fI\fBSDL_JoystickNumBalls\fP\fR
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37 ...\" created by instant / docbook-to-man, Mon 12 Mar 2001, 01:03
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