view docs/man3/SDL_JoystickGetBall.3 @ 852:2651b6b43840

Quartz fix: ut2004 makes a 2D window for the splash screen, which sets the screen surface's pixels field. Then we tear down that video mode and create a GL context, and the Quartz target isn't resetting the pixels field to NULL. When you just create a GL window, the structure is memset'd to zero the first time through, so unless you hit ut2004's codepath, you won't see the bug. :) Without this patch, quitting a windowed ut2003/ut2004 game makes the OS dump a warning about a bogus free() to stderr, but it doesn't actually crash. All we need to do is explicitly initialize the current->pixels field.
author Ryan C. Gordon <icculus@icculus.org>
date Tue, 24 Feb 2004 06:53:22 +0000
parents e5bc29de3f0a
children 546f7c1eb755
line wrap: on
line source

.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