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>
date Wed, 15 Mar 2006 15:47:49 +0000
parents dc6b59e925a2
children 782fd950bd46 c121d94672cb a8e5b518e194
rev   line source
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
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parents: 539
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5
e3b3130f3af8 Date: Fri, 31 Dec 2004 04:14:09 +0900
Sam Lantinga <slouken@libsdl.org>
parents: 539
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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
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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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8 */
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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"
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a9e38f3b8e4d Added MMX audio mixing code for gcc (thanks Stephane!)
Sam Lantinga <slouken@libsdl.org>
parents:
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10
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dc6b59e925a2 Cleaning up warnings on MacOS X
Sam Lantinga <slouken@libsdl.org>
parents: 1402
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11 #if defined(__GNUC__) && defined(__i386__) && defined(SDL_ASSEMBLY_ROUTINES)
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a9e38f3b8e4d Added MMX audio mixing code for gcc (thanks Stephane!)
Sam Lantinga <slouken@libsdl.org>
parents:
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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:
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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>
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14 #endif
a9e38f3b8e4d Added MMX audio mixing code for gcc (thanks Stephane!)
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15