| 1 | .TH "SDL_JoystickGetBall" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" |
| 2 | .SH "NAME" |
| 3 | SDL_JoystickGetBall \- Get relative trackball motion |
| 4 | .SH "SYNOPSIS" |
| 5 | .PP |
| 6 | \fB#include "SDL\&.h" |
| 7 | .sp |
| 8 | \fBint \fBSDL_JoystickGetBall\fP\fR(\fBSDL_Joystick *joystick, int ball, int *dx, int *dy\fR); |
| 9 | .SH "DESCRIPTION" |
| 10 | .PP |
| 11 | Get the \fBball\fR axis change\&. |
| 12 | .PP |
| 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\&. |
| 14 | .SH "RETURN VALUE" |
| 15 | .PP |
| 16 | Returns \fB0\fR on success or \fB-1\fR on failure |
| 17 | .SH "EXAMPLES" |
| 18 | .PP |
| 19 | .PP |
| 20 | .nf |
| 21 | \f(CWint delta_x, delta_y; |
| 22 | SDL_Joystick *joy; |
| 23 | \&. |
| 24 | \&. |
| 25 | \&. |
| 26 | SDL_JoystickUpdate(); |
| 27 | if(SDL_JoystickGetBall(joy, 0, &delta_x, &delta_y)==-1) |
| 28 | printf("TrackBall Read Error! |
| 29 | "); |
| 30 | printf("Trackball Delta- X:%d, Y:%d |
| 31 | ", delta_x, delta_y);\fR |
| 32 | .fi |
| 33 | .PP |
| 34 | .SH "SEE ALSO" |
| 35 | .PP |
| 36 | \fI\fBSDL_JoystickNumBalls\fP\fR |
| 37 | .\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00 |