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Date: Tue, 27 Jul 2004 17:14:00 +0200 From: "Eckhard Stolberg" Subject: Controller names in SDL for Windows I'm working on an Atari 2600 emulator for different systems that uses the SDL. Some time ago someone created an adaptor that lets you use your old Atari controllers with your computer through the USB port. Some of the Atari controllers require special handling by the emulator, so it would be nice, if it would be possible to detect if any of the controllers connected to the computer is this adaptor. SDL would allow that with the SDL_JoystickName function, but unfortunately it doesn't work properly on Windows. On Linux and MacOSX this function returns the name of the controller, but on Windows you'll only get the name of the joystick driver. Most joysticks nowadays use the generic Microsoft driver, so they all return the same name. In an old MSDN article (http://msdn.microsoft.com/archive/default.asp?url=/archive/en-us/dnarinput/html/msdn_extdirect.asp) Microsoft describes how to read out the OEM controller names from the registry. I have implemented this for the SDL controller handler on Windows, and now reading the joystick name works properly there too.
author Sam Lantinga <slouken@libsdl.org>
date Sat, 21 Aug 2004 03:45:58 +0000
parents 355632dca928
children
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<HTML
><HEAD
><TITLE
>Audio Examples</TITLE
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>Audio Examples</H1
><P
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><DIV
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><H2
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><A
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>Opening the audio device</H2
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><PRE
CLASS="PROGRAMLISTING"
>    SDL_AudioSpec wanted;
    extern void fill_audio(void *udata, Uint8 *stream, int len);

    /* Set the audio format */
    wanted.freq = 22050;
    wanted.format = AUDIO_S16;
    wanted.channels = 2;    /* 1 = mono, 2 = stereo */
    wanted.samples = 1024;  /* Good low-latency value for callback */
    wanted.callback = fill_audio;
    wanted.userdata = NULL;

    /* Open the audio device, forcing the desired format */
    if ( SDL_OpenAudio(&#38;wanted, NULL) &#60; 0 ) {
        fprintf(stderr, "Couldn't open audio: %s\n", SDL_GetError());
        return(-1);
    }
    return(0);</PRE
></P
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><A
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>Playing audio</H2
><P
><PRE
CLASS="PROGRAMLISTING"
>    static Uint8 *audio_chunk;
    static Uint32 audio_len;
    static Uint8 *audio_pos;

    /* The audio function callback takes the following parameters:
       stream:  A pointer to the audio buffer to be filled
       len:     The length (in bytes) of the audio buffer
    */
    void fill_audio(void *udata, Uint8 *stream, int len)
    {
        /* Only play if we have data left */
        if ( audio_len == 0 )
            return;

        /* Mix as much data as possible */
        len = ( len &#62; audio_len ? audio_len : len );
        SDL_MixAudio(stream, audio_pos, len, SDL_MIX_MAXVOLUME);
        audio_pos += len;
        audio_len -= len;
    }

    /* Load the audio data ... */

    ;;;;;

    audio_pos = audio_chunk;

    /* Let the callback function play the audio chunk */
    SDL_PauseAudio(0);

    /* Do some processing */

    ;;;;;

    /* Wait for sound to complete */
    while ( audio_len &#62; 0 ) {
        SDL_Delay(100);         /* Sleep 1/10 second */
    }
    SDL_CloseAudio();</PRE
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