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Date: Fri, 13 Feb 2004 17:03:16 +0100 From: Max Horn Subject: Modifier key fix The internal modifier state can get out of sync with reality. To trigger this, do for example this: 1) Launch an SDL app 2) Alt-click on the desktop (this will hide the SDL app). 3) Bring the SDL app back to the front 4) SDL will still think alt is pressed (and as such will treat left clicks like middle clicks). If you press and release alt, it'll be fine again. The attached patch cures this by rechecking the modifier state whenever we process an event.
author Sam Lantinga <slouken@libsdl.org>
date Fri, 13 Feb 2004 17:57:16 +0000
parents 355632dca928
children
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<HTML
><HEAD
><TITLE
>Audio Examples</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+
"><LINK
REL="HOME"
TITLE="SDL Library Documentation"
HREF="index.html"><LINK
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TITLE="Examples"
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TITLE="Event Examples"
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>SDL Library Documentation</TH
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>Chapter 4. Examples</TD
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><DIV
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><H1
CLASS="SECT1"
><A
NAME="GUIDEAUDIOEXAMPLES"
></A
>Audio Examples</H1
><P
></P
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN382"
></A
>Opening the audio device</H2
><P
><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
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN386"
></A
>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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