view docs/html/sdlwasinit.html @ 2042:3908e1f808e1

Fixed bug #292 I might be on crack here. It looks like SDL_ConvertMono() in src/audio/SDL_audiocvt.c adds the left and right channels of a stereo stream together, and clamps the new mono channel if it would overflow. Shouldn't it be dividing by 2 to average the two sample points instead of clamping? Otherwise the mono sample point's volume doubles in the conversion. This would also make the conversion faster, as it replaces two branches per sample frame with a bitwise shift. --ryan.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 24 Sep 2006 15:56:36 +0000
parents 355632dca928
children
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>SDL_WasInit</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN617"
></A
><H2
>Name</H2
>SDL_WasInit&nbsp;--&nbsp;Check which subsystems are initialized</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN620"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
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></A
><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>Uint32 <B
CLASS="FSFUNC"
>SDL_WasInit</B
></CODE
>(Uint32 flags);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN627"
></A
><H2
>Description</H2
><P
><TT
CLASS="FUNCTION"
>SDL_WasInit</TT
> allows you to see which SDL subsytems have been <A
HREF="sdlinit.html"
>initialized</A
>. <TT
CLASS="PARAMETER"
><I
>flags</I
></TT
> is a bitwise OR'd combination of the subsystems you wish to check (see <A
HREF="sdlinit.html"
><TT
CLASS="FUNCTION"
>SDL_Init</TT
></A
> for a list of subsystem flags).</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN635"
></A
><H2
>Return Value</H2
><P
><TT
CLASS="FUNCTION"
>SDL_WasInit</TT
> returns a bitwised OR'd combination of the initialized subsystems.</P
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><A
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><H2
>Examples</H2
><PRE
CLASS="PROGRAMLISTING"
>&#13;/* Here are several ways you can use SDL_WasInit() */

/* Get init data on all the subsystems */
Uint32 subsystem_init;

subsystem_init=SDL_WasInit(SDL_INIT_EVERYTHING);

if(subsystem_init&#38;SDL_INIT_VIDEO)
  printf("Video is initialized.\n");
else
  printf("Video is not initialized.\n");



/* Just check for one specfic subsystem */

if(SDL_WasInit(SDL_INIT_VIDEO)!=0)
  printf("Video is initialized.\n");
else
  printf("Video is not initialized.\n");




/* Check for two subsystems */

Uint32 subsystem_mask=SDL_INIT_VIDEO|SDL_INIT_AUDIO;

if(SDL_WasInit(subsystem_mask)==subsystem_mask)
  printf("Video and Audio initialized.\n");
else
  printf("Video and Audio not initialized.\n");&#13;</PRE
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><A
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><TT
CLASS="FUNCTION"
>SDL_Init</TT
></A
>,
<A
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>SDL_Subsystem</TT
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