view docs/html/sdlpauseaudio.html @ 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 355632dca928
children
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>SDL_PauseAudio</H1
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>Name</H2
>SDL_PauseAudio&nbsp;--&nbsp;Pauses and unpauses the audio callback processing</DIV
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><PRE
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>#include "SDL.h"</PRE
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><CODE
><CODE
CLASS="FUNCDEF"
>void <B
CLASS="FSFUNC"
>SDL_PauseAudio</B
></CODE
>(int pause_on);</CODE
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>Description</H2
><P
>This function pauses and unpauses the audio callback processing.
It should be called with <TT
CLASS="PARAMETER"
><I
>pause_on</I
></TT
>=0 after opening the audio
device to start playing sound.  This is so you can safely initialize
data for your callback function after opening the audio device.
Silence will be written to the audio device during the pause.</P
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>SDL_GetAudioStatus</TT
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>,
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>SDL_OpenAudio</TT
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