.TH "SDL_JoystickGetBall" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" +
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.SH "NAME"+
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SDL_JoystickGetBall\- Get relative trackball motion+
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.SH "SYNOPSIS"+
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.PP+
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\fB#include "SDL\&.h"+
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.sp+
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\fBint \fBSDL_JoystickGetBall\fP\fR(\fBSDL_Joystick *joystick, int ball, int *dx, int *dy\fR);+
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.SH "DESCRIPTION"+
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.PP+
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Get the \fBball\fR axis change\&.+
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.PP+
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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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.SH "RETURN VALUE"+
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.PP+
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Returns \fB0\fR on success or \fB-1\fR on failure+
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.SH "EXAMPLES"+
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.PP+
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.PP+
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.nf+
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\f(CWint delta_x, delta_y;+
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SDL_Joystick *joy;+
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\&.+
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\&.+
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\&.+
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SDL_JoystickUpdate();+
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if(SDL_JoystickGetBall(joy, 0, &delta_x, &delta_y)==-1)+
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  printf("TrackBall Read Error!+
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");+
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printf("Trackball Delta- X:%d, Y:%d+
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", delta_x, delta_y);\fR+
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.fi+
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.PP+
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.SH "SEE ALSO"+
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.PP+
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\fI\fBSDL_JoystickNumBalls\fP\fR+
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...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00+
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