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Date: Tue, 4 Mar 2003 15:05:31 -0800 From: "Jim" Subject: [SDL] Frame Buffer patches... Okay I'm new at patch generation - so please tell me if there's a better way I could have done this. Attached are two patch files generated with 'cvs diff -u' SDL-fb-open-lock.patch applies to SDL_fbvideo.c Modifies the open loop to check /dev/fb/0 found on devfs... Modifies the lock code to return failure if the current virtual terminal is not the one opened for frame buffer writing... Lock would hang forever if switched away (ctrl-alt-F1) ... SDL-fb-mousedrv-screensave.patch applies to SDL_fbevents.c Switches default mouse mode based on SDL_MOUSEDRV - currently only accepts PS2 - otherwise default is MS Mouse. When the screen is switched - exisiting code (wrapped in ifdef SAVE_SCREEN_COTENTS) would save the wrong bit of the screen.... ( I run frame buffer 1600x1200, the size I requested was 800x600 - the save would save the top 800 lines (non biased) and restore them... Adding screen->offset fixed that ) However, if that option is not set, then a call to SDL_UpdateRect (full screen) is made. (which may have had it's contents changed since the screen is not entirely locked because of lock-failure patch) Jim [patches slightly tweaked for SDL 1.2.10]
author Sam Lantinga <slouken@libsdl.org>
date Wed, 22 Mar 2006 07:48:22 +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"
HREF="guideexamples.html"><LINK
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><DIV
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><H1
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><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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