Mercurial > sdl-ios-xcode
view src/thread/epoc/SDL_sysmutex.cpp @ 1544:ab1e4c41ab71
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 | 604d73db6802 |
children | 92947e3a18db |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2006 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA Sam Lantinga slouken@libsdl.org */ /* SDL_sysmutex.cpp Epoc version by Markus Mertama (w@iki.fi) */ /* Mutex functions using the Win32 API */ #include<e32std.h> #include "SDL_error.h" #include "SDL_mutex.h" struct SDL_mutex { TInt handle; }; extern TInt CreateUnique(TInt (*aFunc)(const TDesC& aName, TAny*, TAny*), TAny*, TAny*); TInt NewMutex(const TDesC& aName, TAny* aPtr1, TAny*) { return ((RMutex*)aPtr1)->CreateGlobal(aName); } /* Create a mutex */ SDL_mutex *SDL_CreateMutex(void) { RMutex rmutex; TInt status = CreateUnique(NewMutex, &rmutex, NULL); if(status != KErrNone) { SDL_SetError("Couldn't create mutex"); } SDL_mutex* mutex = new /*(ELeave)*/ SDL_mutex; mutex->handle = rmutex.Handle(); return(mutex); } /* Free the mutex */ void SDL_DestroyMutex(SDL_mutex *mutex) { if ( mutex ) { RMutex rmutex; rmutex.SetHandle(mutex->handle); rmutex.Signal(); rmutex.Close(); delete(mutex); mutex = NULL; } } /* Lock the mutex */ int SDL_mutexP(SDL_mutex *mutex) { if ( mutex == NULL ) { SDL_SetError("Passed a NULL mutex"); return -1; } RMutex rmutex; rmutex.SetHandle(mutex->handle); rmutex.Wait(); return(0); } /* Unlock the mutex */ int SDL_mutexV(SDL_mutex *mutex) { if ( mutex == NULL ) { SDL_SetError("Passed a NULL mutex"); return -1; } RMutex rmutex; rmutex.SetHandle(mutex->handle); rmutex.Signal(); return(0); }