src/audio/dummy/SDL_dummyaudio.c
changeset 1532 30f189cdd82b
child 1533 38c1eb6b0083
     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/audio/dummy/SDL_dummyaudio.c	Tue Mar 14 08:53:33 2006 +0000
     1.3 @@ -0,0 +1,154 @@
     1.4 +/*
     1.5 +    SDL - Simple DirectMedia Layer
     1.6 +    Copyright (C) 1997-2006 Sam Lantinga
     1.7 +
     1.8 +    This library is free software; you can redistribute it and/or
     1.9 +    modify it under the terms of the GNU Lesser General Public
    1.10 +    License as published by the Free Software Foundation; either
    1.11 +    version 2.1 of the License, or (at your option) any later version.
    1.12 +
    1.13 +    This library is distributed in the hope that it will be useful,
    1.14 +    but WITHOUT ANY WARRANTY; without even the implied warranty of
    1.15 +    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    1.16 +    Lesser General Public License for more details.
    1.17 +
    1.18 +    You should have received a copy of the GNU Lesser General Public
    1.19 +    License along with this library; if not, write to the Free Software
    1.20 +    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
    1.21 +
    1.22 +    Sam Lantinga
    1.23 +    slouken@libsdl.org
    1.24 +
    1.25 +    This file hacked^H^H^H^H^H^Hwritten by Ryan C. Gordon
    1.26 +        (icculus@icculus.org)
    1.27 +*/
    1.28 +#include "SDL_config.h"
    1.29 +
    1.30 +/* Output raw audio data to a file. */
    1.31 +
    1.32 +#if HAVE_STDIO_H
    1.33 +#include <stdio.h>
    1.34 +#endif
    1.35 +
    1.36 +#include "SDL_rwops.h"
    1.37 +#include "SDL_timer.h"
    1.38 +#include "SDL_audio.h"
    1.39 +#include "../SDL_audiomem.h"
    1.40 +#include "../SDL_audio_c.h"
    1.41 +#include "../SDL_audiodev_c.h"
    1.42 +#include "SDL_dummyaudio.h"
    1.43 +
    1.44 +/* The tag name used by DUMMY audio */
    1.45 +#define DUMMYAUD_DRIVER_NAME         "dummy"
    1.46 +
    1.47 +/* environment variables and defaults. */
    1.48 +#define DUMMYENVR_WRITEDELAY      "SDL_DUMMYAUDIODELAY"
    1.49 +#define DUMMYDEFAULT_WRITEDELAY   150
    1.50 +
    1.51 +/* Audio driver functions */
    1.52 +static int DUMMYAUD_OpenAudio(_THIS, SDL_AudioSpec *spec);
    1.53 +static void DUMMYAUD_WaitAudio(_THIS);
    1.54 +static void DUMMYAUD_PlayAudio(_THIS);
    1.55 +static Uint8 *DUMMYAUD_GetAudioBuf(_THIS);
    1.56 +static void DUMMYAUD_CloseAudio(_THIS);
    1.57 +
    1.58 +/* Audio driver bootstrap functions */
    1.59 +static int DUMMYAUD_Available(void)
    1.60 +{
    1.61 +	const char *envr = SDL_getenv("SDL_AUDIODRIVER");
    1.62 +	if (envr && (SDL_strcmp(envr, DUMMYAUD_DRIVER_NAME) == 0)) {
    1.63 +		return(1);
    1.64 +	}
    1.65 +	return(0);
    1.66 +}
    1.67 +
    1.68 +static void DUMMYAUD_DeleteDevice(SDL_AudioDevice *device)
    1.69 +{
    1.70 +	SDL_free(device->hidden);
    1.71 +	SDL_free(device);
    1.72 +}
    1.73 +
    1.74 +static SDL_AudioDevice *DUMMYAUD_CreateDevice(int devindex)
    1.75 +{
    1.76 +	SDL_AudioDevice *this;
    1.77 +	const char *envr;
    1.78 +
    1.79 +	/* Initialize all variables that we clean on shutdown */
    1.80 +	this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice));
    1.81 +	if ( this ) {
    1.82 +		SDL_memset(this, 0, (sizeof *this));
    1.83 +		this->hidden = (struct SDL_PrivateAudioData *)
    1.84 +				SDL_malloc((sizeof *this->hidden));
    1.85 +	}
    1.86 +	if ( (this == NULL) || (this->hidden == NULL) ) {
    1.87 +		SDL_OutOfMemory();
    1.88 +		if ( this ) {
    1.89 +			SDL_free(this);
    1.90 +		}
    1.91 +		return(0);
    1.92 +	}
    1.93 +	SDL_memset(this->hidden, 0, (sizeof *this->hidden));
    1.94 +
    1.95 +	envr = SDL_getenv(DUMMYENVR_WRITEDELAY);
    1.96 +	this->hidden->write_delay = (envr) ? SDL_atoi(envr) : DUMMYDEFAULT_WRITEDELAY;
    1.97 +
    1.98 +	/* Set the function pointers */
    1.99 +	this->OpenAudio = DUMMYAUD_OpenAudio;
   1.100 +	this->WaitAudio = DUMMYAUD_WaitAudio;
   1.101 +	this->PlayAudio = DUMMYAUD_PlayAudio;
   1.102 +	this->GetAudioBuf = DUMMYAUD_GetAudioBuf;
   1.103 +	this->CloseAudio = DUMMYAUD_CloseAudio;
   1.104 +
   1.105 +	this->free = DUMMYAUD_DeleteDevice;
   1.106 +
   1.107 +	return this;
   1.108 +}
   1.109 +
   1.110 +AudioBootStrap DUMMYAUD_bootstrap = {
   1.111 +	DUMMYAUD_DRIVER_NAME, "SDL dummy audio driver",
   1.112 +	DUMMYAUD_Available, DUMMYAUD_CreateDevice
   1.113 +};
   1.114 +
   1.115 +/* This function waits until it is possible to write a full sound buffer */
   1.116 +static void DUMMYAUD_WaitAudio(_THIS)
   1.117 +{
   1.118 +	SDL_Delay(this->hidden->write_delay);
   1.119 +}
   1.120 +
   1.121 +static void DUMMYAUD_PlayAudio(_THIS)
   1.122 +{
   1.123 +    /* no-op...this is a null driver. */
   1.124 +}
   1.125 +
   1.126 +static Uint8 *DUMMYAUD_GetAudioBuf(_THIS)
   1.127 +{
   1.128 +	return(this->hidden->mixbuf);
   1.129 +}
   1.130 +
   1.131 +static void DUMMYAUD_CloseAudio(_THIS)
   1.132 +{
   1.133 +	if ( this->hidden->mixbuf != NULL ) {
   1.134 +		SDL_FreeAudioMem(this->hidden->mixbuf);
   1.135 +		this->hidden->mixbuf = NULL;
   1.136 +	}
   1.137 +}
   1.138 +
   1.139 +static int DUMMYAUD_OpenAudio(_THIS, SDL_AudioSpec *spec)
   1.140 +{
   1.141 +#if HAVE_STDIO_H
   1.142 +	fprintf(stderr, "\nWARNING: You are using the SDL dummy audio driver!"
   1.143 +                    " No sound will be output!\n\n");
   1.144 +#endif
   1.145 +
   1.146 +	/* Allocate mixing buffer */
   1.147 +	this->hidden->mixlen = spec->size;
   1.148 +	this->hidden->mixbuf = (Uint8 *) SDL_AllocAudioMem(this->hidden->mixlen);
   1.149 +	if ( this->hidden->mixbuf == NULL ) {
   1.150 +		return(-1);
   1.151 +	}
   1.152 +	SDL_memset(this->hidden->mixbuf, spec->silence, spec->size);
   1.153 +
   1.154 +	/* We're ready to rock and roll. :-) */
   1.155 +	return(0);
   1.156 +}
   1.157 +