/*

SDL - Simple DirectMedia Layer

Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Library General Public

License as published by the Free Software Foundation; either

version 2 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

Library General Public License for more details.

You should have received a copy of the GNU Library General Public

License along with this library; if not, write to the Free

Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

Sam Lantinga

slouken@devolution.com

*/

#ifdef SAVE_RCSID

static char rcsid =

"@(#) $Id$";

#endif

/* Allow access to an ESD network stream mixing buffer */

#ifdef ESD_SUPPORT

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include <errno.h>

#include <signal.h>

#include <unistd.h>

#include <esd.h>

#include "SDL_audio.h"

#include "SDL_error.h"

#include "SDL_audiomem.h"

#include "SDL_audio_c.h"

#include "SDL_timer.h"

#include "SDL_audiodev_c.h"

#include "SDL_esdaudio.h"

/* The tag name used by ESD audio */

#define ESD_DRIVER_NAME "esd"

/* Audio driver functions */

static int ESD_OpenAudio(_THIS, SDL_AudioSpec *spec);

static void ESD_WaitAudio(_THIS);

static void ESD_PlayAudio(_THIS);

static Uint8 *ESD_GetAudioBuf(_THIS);

static void ESD_CloseAudio(_THIS);

/* Audio driver bootstrap functions */

static int Audio_Available(void)

{

int connection;

int available;

available = 0;

connection = esd_open_sound(NULL);

if ( connection >= 0 ) {

available = 1;

esd_close(connection);

}

return(available);

}

static void Audio_DeleteDevice(SDL_AudioDevice *device)

{

free(device->hidden);

free(device);

}

static SDL_AudioDevice *Audio_CreateDevice(int devindex)

{

SDL_AudioDevice *this;

/* Initialize all variables that we clean on shutdown */

this = (SDL_AudioDevice *)malloc(sizeof(SDL_AudioDevice));

if ( this ) {

memset(this, 0, (sizeof *this));

this->hidden = (struct SDL_PrivateAudioData *)

malloc((sizeof *this->hidden));

}

if ( (this == NULL) || (this->hidden == NULL) ) {

SDL_OutOfMemory();

if ( this ) {

free(this);

}

return(0);

}

memset(this->hidden, 0, (sizeof *this->hidden));

audio_fd = -1;

/* Set the function pointers */

this->OpenAudio = ESD_OpenAudio;

this->WaitAudio = ESD_WaitAudio;

this->PlayAudio = ESD_PlayAudio;

this->GetAudioBuf = ESD_GetAudioBuf;

this->CloseAudio = ESD_CloseAudio;

this->free = Audio_DeleteDevice;

return this;

}

AudioBootStrap ESD_bootstrap = {

ESD_DRIVER_NAME, "Enlightened Sound Daemon",

Audio_Available, Audio_CreateDevice

};

/* This function waits until it is possible to write a full sound buffer */

static void ESD_WaitAudio(_THIS)

{

Sint32 ticks;

/* Check to see if the thread-parent process is still alive */

{ static int cnt = 0;

/* Note that this only works with thread implementations

that use a different process id for each thread.

*/

if (parent && (((++cnt)%10) == 0)) { /* Check every 10 loops */

if ( kill(parent, 0) < 0 ) {

this->enabled = 0;

}

}

}

/* Use timer for general audio synchronization */

ticks = ((Sint32)(next_frame - SDL_GetTicks()))-FUDGE_TICKS;

if ( ticks > 0 ) {

SDL_Delay(ticks);

}

}

static void ESD_PlayAudio(_THIS)

{

int written;

/* Write the audio data, checking for EAGAIN on broken audio drivers */

do {

written = write(audio_fd, mixbuf, mixlen);

if ( (written < 0) && ((errno == 0) || (errno == EAGAIN)) ) {

SDL_Delay(1); /* Let a little CPU time go by */

}

} while ( (written < 0) &&

((errno == 0) || (errno == EAGAIN) || (errno == EINTR)) );

/* Set the next write frame */

next_frame += frame_ticks;

/* If we couldn't write, assume fatal error for now */

if ( written < 0 ) {

this->enabled = 0;

}

}

static Uint8 *ESD_GetAudioBuf(_THIS)

{

return(mixbuf);

}

static void ESD_CloseAudio(_THIS)

{

if ( mixbuf != NULL ) {

SDL_FreeAudioMem(mixbuf);

mixbuf = NULL;

}

if ( audio_fd >= 0 ) {

close(audio_fd);

audio_fd = -1;

}

}

/* Try to get the name of the program */

static char *get_progname(void)

{

char *progname = NULL;

#ifdef linux

FILE *fp;

static char temp[BUFSIZ];

sprintf(temp, "/proc/%d/cmdline", getpid());

fp = fopen(temp, "r");

if ( fp != NULL ) {

if ( fgets(temp, sizeof(temp)-1, fp) ) {

progname = strrchr(temp, '/');

if ( progname == NULL ) {

progname = temp;

} else {

progname = progname+1;

}

}

fclose(fp);

}

#endif

return(progname);

}

static int ESD_OpenAudio(_THIS, SDL_AudioSpec *spec)

{

esd_format_t format;

/* Convert audio spec to the ESD audio format */

format = (ESD_STREAM | ESD_PLAY);

switch ( spec->format & 0xFF ) {

case 8:

format |= ESD_BITS8;

break;

case 16:

format |= ESD_BITS16;

break;

default:

SDL_SetError("Unsupported ESD audio format");

return(-1);

}

if ( spec->channels == 1 ) {

format |= ESD_MONO;

} else {

format |= ESD_STEREO;

}

#if 0

spec->samples = ESD_BUF_SIZE; /* Darn, no way to change this yet */

#endif

/* Open a connection to the ESD audio server */

audio_fd = esd_play_stream(format, spec->freq, NULL, get_progname());

if ( audio_fd < 0 ) {

SDL_SetError("Couldn't open ESD connection");

return(-1);

}

/* Calculate the final parameters for this audio specification */

SDL_CalculateAudioSpec(spec);

frame_ticks = (float)(spec->samples*1000)/spec->freq;

next_frame = SDL_GetTicks()+frame_ticks;

/* Allocate mixing buffer */

mixlen = spec->size;

mixbuf = (Uint8 *)SDL_AllocAudioMem(mixlen);

if ( mixbuf == NULL ) {

return(-1);

}

memset(mixbuf, spec->silence, spec->size);

/* Get the parent process id (we're the parent of the audio thread) */

parent = getpid();

/* We're ready to rock and roll. :-) */

return(0);

}

#endif /* ESD_SUPPORT */