Mercurial > sdl-ios-xcode
view src/video/xbios/SDL_xbios_sb3.c @ 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 |
line wrap: on
line source
/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2004 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 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 Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with this library; if not, write to the Free Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA Sam Lantinga slouken@libsdl.org */ #include "SDL_config.h" /* ScreenBlaster 3 functions Patrice Mandin */ /*--- Includes ---*/ #include "SDL_stdinc.h" #include "SDL_xbios.h" #include "SDL_xbios_sb3.h" /*--- Defines ---*/ const int SDL_XBIOS_scpn_planes_device[]={ SCPN_DEV_1BPP, SCPN_DEV_4BPP, SCPN_DEV_8BPP, SCPN_DEV_16BPP, SCPN_DEV_2BPP, SCPN_DEV_4BPP, SCPN_DEV_1BPP }; /*--- Functions ---*/ int SDL_XBIOS_SB3Usable(scpn_cookie_t *cookie_scpn) { scpn_screeninfo_t *scrinfo; int bpp; /* Check if current SB3 mode is usable, i.e. 8 or 16bpp */ scrinfo = cookie_scpn->screen_info; bpp = 1<<(SDL_XBIOS_scpn_planes_device[scrinfo->device]); if ((bpp==8) || (bpp==16)) { return 1; } return 0; } void SDL_XBIOS_SB3Init(_THIS, scpn_cookie_t *cookie_scpn) { scpn_screeninfo_t *scrinfo; /* SB3 prevent changing video modes, we can only use current one */ if (XBIOS_modelist) { SDL_free(XBIOS_modelist); XBIOS_nummodes = 0; XBIOS_modelist = NULL; } scrinfo = cookie_scpn->screen_info; scrinfo->h_pos = scrinfo->v_pos = 0; SDL_XBIOS_AddMode(this, -1, scrinfo->virtual_width, scrinfo->virtual_height, 1<<(SDL_XBIOS_scpn_planes_device[scrinfo->device]), SDL_FALSE ); }