view docs/man3/SDL_WasInit.3 @ 638:b0108e9dea53

Date: Sun, 11 May 2003 19:59:06 +0300 From: Pasi K?rkk?inen Subject: [PATCH] fix SDL OpenGL segfault with DRI/Mesa drivers and Glew Hello! The attached patch fixes a bug in SDL which causes SDL to crash in X11_GL_Shutdown() if you are using DRI/Mesa drivers AND glew (http://glew.sf.net). The bug is caused by a namespace collision affecting dlsym() to fetch wrong pointer for glXReleaseBuffersMESA() (uninitialized pointer from glew because the extension is NOT supported by the driver) and then SDL calling it in X11_GL_Shutdown(). SDL should check if the glXReleaseBuffersMESA() is really supported by the driver (from the extensions string) before calling it. Attached patch adds extension string parsing to check if glXReleaseBuffersMESA() is really supported (and this way prevents the segfault). Availability of the extensions should be _always_ checked from the extensions string rather than using dlsym()! Please add it to the next version of SDL. Thanks to gltron and author of glew to help fixing this.
author Sam Lantinga <slouken@libsdl.org>
date Sat, 28 Jun 2003 17:27:33 +0000
parents e5bc29de3f0a
children 546f7c1eb755
line wrap: on
line source

.TH "SDL_WasInit" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_WasInit\- Check which subsystems are initialized
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBUint32 \fBSDL_WasInit\fP\fR(\fBUint32 flags\fR);
.SH "DESCRIPTION"
.PP
\fBSDL_WasInit\fP allows you to see which SDL subsytems have been \fIinitialized\fR\&. \fBflags\fR is a bitwise OR\&'d combination of the subsystems you wish to check (see \fI\fBSDL_Init\fP\fR for a list of subsystem flags)\&.
.SH "RETURN VALUE"
.PP
\fBSDL_WasInit\fP returns a bitwised OR\&'d combination of the initialized subsystems\&.
.SH "EXAMPLES"
.PP
.nf
\f(CW
/* Here are several ways you can use SDL_WasInit() */

/* Get init data on all the subsystems */
Uint32 subsystem_init;

subsystem_init=SDL_WasInit(SDL_INIT_EVERYTHING);

if(subsystem_init&SDL_INIT_VIDEO)
  printf("Video is initialized\&.
");
else
  printf("Video is not initialized\&.
");



/* Just check for one specfic subsystem */

if(SDL_WasInit(SDL_INIT_VIDEO)!=0)
  printf("Video is initialized\&.
");
else
  printf("Video is not initialized\&.
");




/* Check for two subsystems */

Uint32 subsystem_mask=SDL_INIT_VIDEO|SDL_INIT_AUDIO;

if(SDL_WasInit(subsystem_mask)==subsystem_mask)
  printf("Video and Audio initialized\&.
");
else
  printf("Video and Audio not initialized\&.
");
\fR
.fi
.PP
.SH "SEE ALSO"
.PP
\fI\fBSDL_Init\fP\fR, \fI\fBSDL_Subsystem\fP\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00