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view docs/html/sdlmixaudio.html @ 715:de0351c47596
Date: Mon, 01 Sep 2003 15:37:52 +0900
From: SUGIMOTO Sadahiro
Subject: [SDL] [PATCH] bsd joystick
Hi,
on FreeBSD systems, I had troubles using a USB joystick with SDL.
There are two problems in src/joystick/bsd/SDL_sysjoystick.c .
1. The macro __FreeBSD_version is compared to inappropriate numbers.
According to
http://www.jp.freebsd.org/cgi/cvsweb.cgi/src/lib/libusbhid/usbhid.h
http://www.jp.freebsd.org/cgi/cvsweb.cgi/src/lib/libusbhid/Attic/libusb.h
http://www.jp.freebsd.org/cgi/cvsweb.cgi/src/lib/libusbhid/Attic/libusbhid.h
the APIs of USB HID are common in each following groups of OS versions,
a. 4.1-4.5
b. 4.6-4.8, and 5.0
c. 5.1
2. open() error
$ uname -sr
FreeBSD 5.1-RELEASE
$ ls -l /dev/uhid0
crw-r--r-- 1 root operator 122, 0 8 3 14:06 /dev/uhid0
Then, open("/dev/uhid0", O_RDWR) fails.
It seems that this device file does not need to be writable, so O_RDONLY
may be suitable.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Fri, 05 Sep 2003 15:20:47 +0000 |
parents | e5bc29de3f0a |
children | 355632dca928 |
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<HTML ><HEAD ><TITLE >SDL_MixAudio</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.64 "><LINK REL="HOME" TITLE="SDL Library Documentation" HREF="index.html"><LINK REL="UP" TITLE="Audio" HREF="audio.html"><LINK REL="PREVIOUS" TITLE="SDL_ConvertAudio" HREF="sdlconvertaudio.html"><LINK REL="NEXT" TITLE="SDL_LockAudio" HREF="sdllockaudio.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFF8DC" TEXT="#000000" LINK="#0000ee" VLINK="#551a8b" ALINK="#ff0000" ><DIV CLASS="NAVHEADER" ><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >SDL Library Documentation</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="sdlconvertaudio.html" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdllockaudio.html" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLMIXAUDIO" >SDL_MixAudio</A ></H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN6719" ></A ><H2 >Name</H2 >SDL_MixAudio -- Mix audio data</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN6722" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN6723" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >void <B CLASS="FSFUNC" >SDL_MixAudio</B ></CODE >(Uint8 *dst, Uint8 *src, Uint32 len, int volume);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN6729" ></A ><H2 >Description</H2 ><P >This function takes two audio buffers of <TT CLASS="PARAMETER" ><I >len</I ></TT > bytes each of the playing audio format and mixes them, performing addition, volume adjustment, and overflow clipping. The <TT CLASS="PARAMETER" ><I >volume</I ></TT > ranges from 0 to <TT CLASS="LITERAL" >SDL_MIX_MAXVOLUME</TT > and should be set to the maximum value for full audio volume. Note this does not change hardware volume. This is provided for convenience -- you can mix your own audio data.</P ><DIV CLASS="NOTE" ><BLOCKQUOTE CLASS="NOTE" ><P ><B >Note: </B >Do not use this function for mixing together more than two streams of sample data. The output from repeated application of this function may be distorted by clipping, because there is no accumulator with greater range than the input (not to mention this being an inefficient way of doing it). Use mixing functions from SDL_mixer, OpenAL, or write your own mixer instead.</P ></BLOCKQUOTE ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN6737" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlopenaudio.html" ><TT CLASS="FUNCTION" >SDL_OpenAudio</TT ></A ></P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sdlconvertaudio.html" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sdllockaudio.html" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_ConvertAudio</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="audio.html" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_LockAudio</TD ></TR ></TABLE ></DIV ></BODY ></HTML >