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Fixed bug #33 Mike Frysinger wrote: > with libsdl-1.2.9, some games (like bomberclone) started > segfaulting in Gentoo [...snip...] > the last change in the last hunk: [...snip...] > if i change the statement to read: > (table[which].blit_features & GetBlitFeatures()) == GetBlitFeatures() > bomberclone no longer segfaults on my box Alex Volkov wrote: > The test "(table[which].blit_features & GetBlitFeatures()) == > table[which].blit_features)" is correct, and the previous > "(table[which].cpu_mmx == SDL_HasMMX())" was actually broken. I think there is potentially a slightly different cause of the above problem. During the introduction of the Altivec code, the blit_table struct field 'alpha' got changed from a straightforward enum to a bitmask, which makes perfect sense by itself. However, now the table driven blitter selection code in SDL_CalculateBlitN() can choose the wrong blitters when searching for a NO_ALPHA blitter because of the following code: int a_need = 0; ... (a_need & table[which].alpha) == a_need && When searching through the normal_blit_2[] table, a SET_ALPHA blitter (like Blit_RGB565_ARGB8888) can now be selected instead of a NO_ALPHA one, causing alpha channel bits to appear in a non-alpha destination surface. I suppose this could theoretically be an indirect cause of the segfault mentioned above. I *think* this can be fixed by changing to int a_need = NO_ALPHA;
author Sam Lantinga <slouken@libsdl.org>
date Wed, 15 Mar 2006 15:47:49 +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