Mercurial > sdl-ios-xcode
annotate src/audio/SDL_mixer_MMX.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> |
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date | Wed, 15 Mar 2006 15:47:49 +0000 |
parents | dc6b59e925a2 |
children | 782fd950bd46 c121d94672cb a8e5b518e194 |
rev | line source |
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1019
e3b3130f3af8
Date: Fri, 31 Dec 2004 04:14:09 +0900
Sam Lantinga <slouken@libsdl.org>
parents:
539
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1 /* |
e3b3130f3af8
Date: Fri, 31 Dec 2004 04:14:09 +0900
Sam Lantinga <slouken@libsdl.org>
parents:
539
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2 headers for MMX assembler version of SDL_MixAudio |
e3b3130f3af8
Date: Fri, 31 Dec 2004 04:14:09 +0900
Sam Lantinga <slouken@libsdl.org>
parents:
539
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3 Copyright 2002 Stephane Marchesin (stephane.marchesin@wanadoo.fr) |
e3b3130f3af8
Date: Fri, 31 Dec 2004 04:14:09 +0900
Sam Lantinga <slouken@libsdl.org>
parents:
539
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4 This code is licensed under the LGPL (see COPYING for details) |
e3b3130f3af8
Date: Fri, 31 Dec 2004 04:14:09 +0900
Sam Lantinga <slouken@libsdl.org>
parents:
539
diff
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5 |
e3b3130f3af8
Date: Fri, 31 Dec 2004 04:14:09 +0900
Sam Lantinga <slouken@libsdl.org>
parents:
539
diff
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6 Assumes buffer size in bytes is a multiple of 16 |
e3b3130f3af8
Date: Fri, 31 Dec 2004 04:14:09 +0900
Sam Lantinga <slouken@libsdl.org>
parents:
539
diff
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7 Assumes SDL_MIX_MAXVOLUME = 128 |
e3b3130f3af8
Date: Fri, 31 Dec 2004 04:14:09 +0900
Sam Lantinga <slouken@libsdl.org>
parents:
539
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changeset
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8 */ |
1402
d910939febfa
Use consistent identifiers for the various platforms we support.
Sam Lantinga <slouken@libsdl.org>
parents:
1019
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9 #include "SDL_config.h" |
539
a9e38f3b8e4d
Added MMX audio mixing code for gcc (thanks Stephane!)
Sam Lantinga <slouken@libsdl.org>
parents:
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10 |
1487
dc6b59e925a2
Cleaning up warnings on MacOS X
Sam Lantinga <slouken@libsdl.org>
parents:
1402
diff
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11 #if defined(__GNUC__) && defined(__i386__) && defined(SDL_ASSEMBLY_ROUTINES) |
539
a9e38f3b8e4d
Added MMX audio mixing code for gcc (thanks Stephane!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff
changeset
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12 void SDL_MixAudio_MMX_S16(char* ,char* ,unsigned int ,int ); |
a9e38f3b8e4d
Added MMX audio mixing code for gcc (thanks Stephane!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff
changeset
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13 void SDL_MixAudio_MMX_S8(char* ,char* ,unsigned int ,int ); |
a9e38f3b8e4d
Added MMX audio mixing code for gcc (thanks Stephane!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff
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14 #endif |
a9e38f3b8e4d
Added MMX audio mixing code for gcc (thanks Stephane!)
Sam Lantinga <slouken@libsdl.org>
parents:
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15 |