view src/audio/SDL_sysaudio.h @ 3798:c8b3d3d13ed1 SDL-ryan-multiple-audio-device

Audio bootstraps can now specify that a driver is only to be used if explicitly requested (for things like the "disk" driver that is always available but you would never want to default to using). Trimmed out code that can be handled by stubs in the core. The "dummy" driver is pretty damned small now. :)
author Ryan C. Gordon <icculus@icculus.org>
date Wed, 04 Oct 2006 21:27:53 +0000
parents b19680c84cdf
children b12b7ec0dfcc
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 Sam Lantinga

    This library is SDL_free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

#ifndef _SDL_sysaudio_h
#define _SDL_sysaudio_h

#include "SDL_mutex.h"
#include "SDL_thread.h"

/* The SDL audio driver */
typedef struct SDL_AudioDevice SDL_AudioDevice;
#define _THIS	SDL_AudioDevice *_this

typedef struct SDL_AudioDriverImpl
{
    int (*DetectDevices)(int iscapture);
    const char *(*GetDeviceName)(int index, int iscapture);
    int (*OpenDevice) (_THIS, const char *devname, int iscapture);
    void (*ThreadInit) (_THIS); /* Called by audio thread at start */
    void (*WaitDevice) (_THIS);
    void (*PlayDevice) (_THIS);
    Uint8 *(*GetDeviceBuf) (_THIS);
    void (*WaitDone) (_THIS);
    void (*CloseDevice) (_THIS);
    void (*LockDevice) (_THIS);
    void (*UnlockDevice) (_THIS);
    void (*Deinitialize) (void);

    /* Some flags to push duplicate code into the core and reduce #ifdefs. */
    int ProvidesOwnCallbackThread:1;
    int SkipMixerLock:1;
    int HasCaptureSupport:1;
    int OnlyHasDefaultOutputDevice:1;
    int OnlyHasDefaultInputDevice:1;
} SDL_AudioDriverImpl;


typedef struct SDL_AudioDriver
{
    /* * * */
    /* The name of this audio driver */
    const char *name;

    /* * * */
    /* The description of this audio driver */
    const char *desc;

    SDL_AudioDriverImpl impl;
} SDL_AudioDriver;


/* Define the SDL audio driver structure */
struct SDL_AudioDevice
{
    /* * * */
    /* Data common to all devices */

    /* The current audio specification (shared with audio thread) */
    SDL_AudioSpec spec;

    /* An audio conversion block for audio format emulation */
    SDL_AudioCVT convert;

    /* Current state flags */
    int iscapture;
    int enabled;
    int paused;
    int opened;

    /* Fake audio buffer for when the audio hardware is busy */
    Uint8 *fake_stream;

    /* A semaphore for locking the mixing buffers */
    SDL_mutex *mixer_lock;

    /* A thread to feed the audio device */
    SDL_Thread *thread;
    Uint32 threadid;

    /* * * */
    /* Data private to this driver */
    struct SDL_PrivateAudioData *hidden;
};
#undef _THIS

typedef struct AudioBootStrap
{
    const char *name;
    const char *desc;
    int (*available) (void);
    int (*init) (SDL_AudioDriverImpl *impl);
    int demand:1;  /* 1==must request explicitly, or it won't be available. */
} AudioBootStrap;

#endif /* _SDL_sysaudio_h */
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