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Some cleanups on the new XInput code. One or two things got moved around, but largely this is hooked up correctly in the Unix configure system now: it can be dynamically loaded and fallback gracefully if not available, or libXi can be directly linked to libSDL. XInput support can be --disable'd from the configure script, too (defaults to enabled). Please note that while the framework is in place to gracefully fallback, the current state of the source requires XInput. We'll need to adjust a few things still to correct this.
author Ryan C. Gordon <icculus@icculus.org>
date Wed, 17 Sep 2008 08:20:57 +0000
parents 355632dca928
children
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<HTML
><HEAD
><TITLE
>SDL_AudioSpec</TITLE
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><H1
><A
NAME="SDLAUDIOSPEC"
></A
>SDL_AudioSpec</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN6507"
></A
><H2
>Name</H2
>SDL_AudioSpec&nbsp;--&nbsp;Audio Specification Structure</DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN6510"
></A
><H2
>Structure Definition</H2
><PRE
CLASS="PROGRAMLISTING"
>typedef struct{
  int freq;
  Uint16 format;
  Uint8 channels;
  Uint8 silence;
  Uint16 samples;
  Uint32 size;
  void (*callback)(void *userdata, Uint8 *stream, int len);
  void *userdata;
} SDL_AudioSpec;</PRE
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN6513"
></A
><H2
>Structure Data</H2
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN6515"
></A
><P
></P
><TABLE
BORDER="0"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>freq</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Audio frequency in samples per second</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>format</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Audio data format</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>channels</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Number of channels: 1 mono, 2 stereo</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>silence</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Audio buffer silence value (calculated)</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>samples</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Audio buffer size in samples</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>size</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Audio buffer size in bytes (calculated)</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>callback(..)</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Callback function for filling the audio buffer</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>userdata</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Pointer the user data which is passed to the callback function</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN6550"
></A
><H2
>Description</H2
><P
>The <SPAN
CLASS="STRUCTNAME"
>SDL_AudioSpec</SPAN
> structure is used to describe the format of some audio data. This structure is used by <A
HREF="sdlopenaudio.html"
><TT
CLASS="FUNCTION"
>SDL_OpenAudio</TT
></A
> and <A
HREF="sdlloadwav.html"
><TT
CLASS="FUNCTION"
>SDL_LoadWAV</TT
></A
>. While all fields are used by <TT
CLASS="FUNCTION"
>SDL_OpenAudio</TT
> only <TT
CLASS="STRUCTFIELD"
><I
>freq</I
></TT
>, <TT
CLASS="STRUCTFIELD"
><I
>format</I
></TT
>, <TT
CLASS="STRUCTFIELD"
><I
>samples</I
></TT
> and <TT
CLASS="STRUCTFIELD"
><I
>channels</I
></TT
> are used by <TT
CLASS="FUNCTION"
>SDL_LoadWAV</TT
>. We will detail these common members here.</P
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN6564"
></A
><P
></P
><TABLE
BORDER="0"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>freq</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
><P
>The number of samples sent to the sound device every second. Common values are 11025, 22050 and 44100. The higher the better.</P
></TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>format</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
><P
>Specifies the size and type of each sample element
<P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="LITERAL"
>AUDIO_U8</TT
></DT
><DD
><P
>Unsigned 8-bit samples</P
></DD
><DT
><TT
CLASS="LITERAL"
>AUDIO_S8</TT
></DT
><DD
><P
>Signed 8-bit samples</P
></DD
><DT
><TT
CLASS="LITERAL"
>AUDIO_U16</TT
> or <TT
CLASS="LITERAL"
>AUDIO_U16LSB</TT
></DT
><DD
><P
>Unsigned 16-bit little-endian samples</P
></DD
><DT
><TT
CLASS="LITERAL"
>AUDIO_S16</TT
> or <TT
CLASS="LITERAL"
>AUDIO_S16LSB</TT
></DT
><DD
><P
>Signed 16-bit little-endian samples</P
></DD
><DT
><TT
CLASS="LITERAL"
>AUDIO_U16MSB</TT
></DT
><DD
><P
>Unsigned 16-bit big-endian samples</P
></DD
><DT
><TT
CLASS="LITERAL"
>AUDIO_S16MSB</TT
></DT
><DD
><P
>Signed 16-bit big-endian samples</P
></DD
><DT
><TT
CLASS="LITERAL"
>AUDIO_U16SYS</TT
></DT
><DD
><P
>Either <TT
CLASS="LITERAL"
>AUDIO_U16LSB</TT
> or <TT
CLASS="LITERAL"
>AUDIO_U16MSB</TT
> depending on you systems endianness</P
></DD
><DT
><TT
CLASS="LITERAL"
>AUDIO_S16SYS</TT
></DT
><DD
><P
>Either <TT
CLASS="LITERAL"
>AUDIO_S16LSB</TT
> or <TT
CLASS="LITERAL"
>AUDIO_S16MSB</TT
> depending on you systems endianness</P
></DD
></DL
></DIV
></P
></TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>channels</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>The number of seperate sound channels. 1 is mono (single channel), 2 is stereo (dual channel).</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>samples</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>When used with <A
HREF="sdlopenaudio.html"
><TT
CLASS="FUNCTION"
>SDL_OpenAudio</TT
></A
> this refers to the size of the audio buffer in samples. A sample a chunk of audio data of the size specified in <TT
CLASS="PARAMETER"
><I
>format</I
></TT
> mulitplied by the number of channels. When the <SPAN
CLASS="STRUCTNAME"
>SDL_AudioSpec</SPAN
> is used with <A
HREF="sdlloadwav.html"
><TT
CLASS="FUNCTION"
>SDL_LoadWAV</TT
></A
> <TT
CLASS="STRUCTFIELD"
><I
>samples</I
></TT
> is set to 4096.</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN6639"
></A
><H2
>See Also</H2
><P
><A
HREF="sdlopenaudio.html"
><TT
CLASS="FUNCTION"
>SDL_OpenAudio</TT
></A
>,
<A
HREF="sdlloadwav.html"
><TT
CLASS="FUNCTION"
>SDL_LoadWAV</TT
></A
></P
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