Mercurial > sdl-ios-xcode
view include/SDL_loadso.h @ 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 | c71e05b4dc2e |
children | 782fd950bd46 c121d94672cb a1b03ba2fcd0 |
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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 */ /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /* System dependent library loading routines */ /* Some things to keep in mind: - These functions only work on C function names. Other languages may have name mangling and intrinsic language support that varies from compiler to compiler. - Make sure you declare your function pointers with the same calling convention as the actual library function. Your code will crash mysteriously if you do not do this. - Avoid namespace collisions. If you load a symbol from the library, it is not defined whether or not it goes into the global symbol namespace for the application. If it does and it conflicts with symbols in your code or other shared libraries, you will not get the results you expect. :) */ #ifndef _SDL_loadso_h #define _SDL_loadso_h #include "SDL_stdinc.h" #include "SDL_error.h" #include "begin_code.h" /* Set up for C function definitions, even when using C++ */ #ifdef __cplusplus extern "C" { #endif /* This function dynamically loads a shared object and returns a pointer * to the object handle (or NULL if there was an error). * The 'sofile' parameter is a system dependent name of the object file. */ extern DECLSPEC void * SDLCALL SDL_LoadObject(const char *sofile); /* Given an object handle, this function looks up the address of the * named function in the shared object and returns it. This address * is no longer valid after calling SDL_UnloadObject(). */ extern DECLSPEC void * SDLCALL SDL_LoadFunction(void *handle, const char *name); /* Unload a shared object from memory */ extern DECLSPEC void SDLCALL SDL_UnloadObject(void *handle); /* Ends C function definitions when using C++ */ #ifdef __cplusplus } #endif #include "close_code.h" #endif /* _SDL_loadso_h */