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