Mercurial > sdl-ios-xcode
view src/video/aalib/SDL_aavideo.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 | d910939febfa |
| children | 782fd950bd46 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 */ #include "SDL_config.h" #ifndef _SDL_aavideo_h #define _SDL_aavideo_h #include "SDL_mouse.h" #include "SDL_mutex.h" #include "../SDL_sysvideo.h" #include <aalib.h> /* Hidden "this" pointer for the video functions */ #define _THIS SDL_VideoDevice *this #define SDL_NUMMODES 6 /* Private display data */ struct SDL_PrivateVideoData { SDL_Rect *SDL_modelist[SDL_NUMMODES+1]; aa_context *context; aa_palette palette; aa_renderparams *rparams; double x_ratio, y_ratio; int w, h; SDL_mutex *mutex; int in_x11; void *buffer; }; /* Old variable names */ #define SDL_modelist (this->hidden->SDL_modelist) #define AA_context (this->hidden->context) #define AA_palette (this->hidden->palette) #define AA_rparams (this->hidden->rparams) #define AA_buffer (this->hidden->buffer) #define AA_x_ratio (this->hidden->x_ratio) #define AA_y_ratio (this->hidden->y_ratio) #define AA_mutex (this->hidden->mutex) #define AA_in_x11 (this->hidden->in_x11) #define AA_w (this->hidden->w) #define AA_h (this->hidden->h) #endif /* _SDL_aavideo_h */