Mercurial > sdl-ios-xcode
view src/video/SDL_pixels_c.h @ 3899:081aecdb0911 SDL-1.2
From: Gabriel Gambetta
To: SDL Mailing List <sdl@libsdl.org>
Date: Fri, 17 Nov 2006 00:39:29 -0200
Subject: [SDL] Alpha blending bug - fixed?
It turns out mm5 never got the correct value. This failed :
[...]
"movd %1, %%mm5\n\t"
: : "m" (amask), "m" (sf->Ashift) );
mm5 got 0xFF000018 instead of 0x00000018. However I did this :
Uint32 ashift = sf->Ashift;
[...]
"movd %1, %%mm5\n\t"
: : "m" (amask), "m" (ashift) );
and everything worked fine.
The only thing I could find out was that ashift is 32-bit aligned but
sf->Ashift isn't:
printf("ashift %8X [%d]\n", &ashift, (int)(&ashift) % 4);
printf("sf->Ashift %8X [%d]\n", &sf->Ashift, (int)(&sf->Ashift) % 4);
ashift at BFF0E0C4 [0]
sf->Ashift at 08AFB9CD [1]
Could this be the problem? If it is, the fix is extremely trivial.
Should I submit a patch?
--Gabriel
author | Ryan C. Gordon <icculus@icculus.org> |
---|---|
date | Tue, 21 Nov 2006 23:17:00 +0000 |
parents | d910939febfa |
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 */ #include "SDL_config.h" /* Useful functions and variables from SDL_pixel.c */ #include "SDL_blit.h" /* Pixel format functions */ extern SDL_PixelFormat *SDL_AllocFormat(int bpp, Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask); extern SDL_PixelFormat *SDL_ReallocFormat(SDL_Surface *surface, int bpp, Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask); extern void SDL_FormatChanged(SDL_Surface *surface); extern void SDL_FreeFormat(SDL_PixelFormat *format); /* Blit mapping functions */ extern SDL_BlitMap *SDL_AllocBlitMap(void); extern void SDL_InvalidateMap(SDL_BlitMap *map); extern int SDL_MapSurface (SDL_Surface *src, SDL_Surface *dst); extern void SDL_FreeBlitMap(SDL_BlitMap *map); /* Miscellaneous functions */ extern Uint16 SDL_CalculatePitch(SDL_Surface *surface); extern void SDL_DitherColors(SDL_Color *colors, int bpp); extern Uint8 SDL_FindColor(SDL_Palette *pal, Uint8 r, Uint8 g, Uint8 b); extern void SDL_ApplyGamma(Uint16 *gamma, SDL_Color *colors, SDL_Color *output, int ncolors);