Mercurial > sdl-ios-xcode
view src/video/fbcon/3dfx_regs.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 _3DFX_REGS_H #define _3DFX_REGS_H /* This information comes from the public 3Dfx specs for the Voodoo 3000 */ /* mapped_io register offsets */ #define TDFX_STATUS 0x00 #define INTCTRL (0x00100000 + 0x04) #define CLIP0MIN (0x00100000 + 0x08) #define CLIP0MAX (0x00100000 + 0x0c) #define DSTBASE (0x00100000 + 0x10) #define DSTFORMAT (0x00100000 + 0x14) #define SRCCOLORKEYMIN (0x00100000 + 0x18) #define SRCCOLORKEYMAX (0x00100000 + 0x1c) #define DSTCOLORKEYMIN (0x00100000 + 0x20) #define DSTCOLORKEYMAX (0x00100000 + 0x24) #define BRESERROR0 (0x00100000 + 0x28) #define BRESERROR1 (0x00100000 + 0x2c) #define ROP_2D (0x00100000 + 0x30) #define SRCBASE (0x00100000 + 0x34) #define COMMANDEXTRA_2D (0x00100000 + 0x38) #define PATTERN0 (0x00100000 + 0x44) #define PATTERN1 (0x00100000 + 0x48) #define CLIP1MIN (0x00100000 + 0x4c) #define CLIP1MAX (0x00100000 + 0x50) #define SRCFORMAT (0x00100000 + 0x54) #define SRCSIZE (0x00100000 + 0x58) #define SRCXY (0x00100000 + 0x5c) #define COLORBACK (0x00100000 + 0x60) #define COLORFORE (0x00100000 + 0x64) #define DSTSIZE (0x00100000 + 0x68) #define DSTXY (0x00100000 + 0x6c) #define COMMAND_2D (0x00100000 + 0x70) #define LAUNCH_2D (0x00100000 + 0x80) #define PATTERNBASE (0x00100000 + 0x100) #define COMMAND_3D (0x00200000 + 0x120) /* register bitfields (not all, only as needed) */ #define BIT(x) (1UL << (x)) #define COMMAND_2D_BITBLT 0x01 #define COMMAND_2D_FILLRECT 0x05 #define COMMAND_2D_LINE 0x06 #define COMMAND_2D_POLYGON_FILL 0x08 #define COMMAND_2D_INITIATE BIT(8) #define COMMAND_2D_REVERSELINE BIT(9) #define COMMAND_2D_STIPPLELINE BIT(12) #define COMMAND_2D_MONOCHROME_PATT BIT(13) #define COMMAND_2D_MONOCHROME_TRANSP BIT(16) #define COMMAND_3D_NOP 0x00 #define STATUS_RETRACE BIT(6) #define STATUS_BUSY BIT(9) #endif /* _3DFX_REGS_H */