/*

    SDL - Simple DirectMedia Layer

    Copyright (C) 1997-2004 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@libsdl.org

*/

#include "SDL_config.h"

/*

 * Driver for native OpenBSD/NetBSD audio(4).

 * vedge@vedge.com.ar.

 */

#include <errno.h>

#include <unistd.h>

#include <fcntl.h>

#include <sys/time.h>

#include <sys/ioctl.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <sys/audioio.h>

#include "SDL_timer.h"

#include "SDL_audio.h"

#include "../SDL_audiomem.h"

#include "../SDL_audio_c.h"

#include "../SDL_audiodev_c.h"

#include "SDL_bsdaudio.h"

/* The tag name used by NetBSD/OpenBSD audio */

#ifdef __NetBSD__

#define BSD_AUDIO_DRIVER_NAME         "netbsd"

#define BSD_AUDIO_DRIVER_DESC         "Native NetBSD audio"

#else

#define BSD_AUDIO_DRIVER_NAME         "openbsd"

#define BSD_AUDIO_DRIVER_DESC         "Native OpenBSD audio"

#endif

/* Open the audio device for playback, and don't block if busy */

/* #define USE_BLOCKING_WRITES */

/* Use timer for synchronization */

/* #define USE_TIMER_SYNC */

/* #define DEBUG_AUDIO */

/* #define DEBUG_AUDIO_STREAM */

#ifdef USE_BLOCKING_WRITES

#define OPEN_FLAGS	O_WRONLY

#else

#define OPEN_FLAGS	(O_WRONLY|O_NONBLOCK)

#endif

/* Audio driver functions */

static void OBSD_WaitAudio(_THIS);

static int OBSD_OpenAudio(_THIS, SDL_AudioSpec * spec);

static void OBSD_PlayAudio(_THIS);

static Uint8 *OBSD_GetAudioBuf(_THIS);

static void OBSD_CloseAudio(_THIS);

#ifdef DEBUG_AUDIO

static void OBSD_Status(_THIS);

#endif

/* Audio driver bootstrap functions */

static int

Audio_Available(void)

{

    int fd;

    int available;

    available = 0;

    fd = SDL_OpenAudioPath(NULL, 0, OPEN_FLAGS, 0);

    if (fd >= 0) {

        available = 1;

        close(fd);

    }

    return (available);

}

static void

Audio_DeleteDevice(SDL_AudioDevice * device)

{

    SDL_free(device->hidden);

    SDL_free(device);

}

static SDL_AudioDevice *

Audio_CreateDevice(int devindex)

{

    SDL_AudioDevice *this;

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

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

    if (this) {

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

        this->hidden = (struct SDL_PrivateAudioData *)

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

    }

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

        SDL_OutOfMemory();

        if (this)

            SDL_free(this);

        return (0);

    }

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

    audio_fd = -1;

    /* Set the function pointers */

    this->OpenAudio = OBSD_OpenAudio;

    this->WaitAudio = OBSD_WaitAudio;

    this->PlayAudio = OBSD_PlayAudio;

    this->GetAudioBuf = OBSD_GetAudioBuf;

    this->CloseAudio = OBSD_CloseAudio;

    this->free = Audio_DeleteDevice;

    return this;

}

AudioBootStrap BSD_AUDIO_bootstrap = {

    BSD_AUDIO_DRIVER_NAME, BSD_AUDIO_DRIVER_DESC,

    Audio_Available, Audio_CreateDevice

};

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

static void

OBSD_WaitAudio(_THIS)

{

#ifndef USE_BLOCKING_WRITES     /* Not necessary when using blocking writes */

    /* See if we need to use timed audio synchronization */

    if (frame_ticks) {

        /* Use timer for general audio synchronization */

        Sint32 ticks;

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

        if (ticks > 0) {

            SDL_Delay(ticks);

        }

    } else {

        /* Use select() for audio synchronization */

        fd_set fdset;

        struct timeval timeout;

        FD_ZERO(&fdset);

        FD_SET(audio_fd, &fdset);

        timeout.tv_sec = 10;

        timeout.tv_usec = 0;

#ifdef DEBUG_AUDIO

        fprintf(stderr, "Waiting for audio to get ready\n");

#endif

        if (select(audio_fd + 1, NULL, &fdset, NULL, &timeout) <= 0) {

            const char *message =

                "Audio timeout - buggy audio driver? (disabled)";

            /* In general we should never print to the screen,

               but in this case we have no other way of letting

               the user know what happened.

             */

            fprintf(stderr, "SDL: %s\n", message);

            this->enabled = 0;

            /* Don't try to close - may hang */

            audio_fd = -1;

#ifdef DEBUG_AUDIO

            fprintf(stderr, "Done disabling audio\n");

#endif

        }

#ifdef DEBUG_AUDIO

        fprintf(stderr, "Ready!\n");

#endif

    }

#endif /* !USE_BLOCKING_WRITES */

}

static void

OBSD_PlayAudio(_THIS)

{

    int written, p = 0;

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

    do {

        written = write(audio_fd, &mixbuf[p], mixlen - p);

        if (written > 0)

            p += written;

        if (written == -1 && errno != 0 && errno != EAGAIN && errno != EINTR) {

            /* Non recoverable error has occurred. It should be reported!!! */

            perror("audio");

            break;

        }

        if (p < written

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

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

        }

    }

    while (p < written);

    /* If timer synchronization is enabled, set the next write frame */

    if (frame_ticks) {

        next_frame += frame_ticks;

    }

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

    if (written < 0) {

        this->enabled = 0;

    }

#ifdef DEBUG_AUDIO

    fprintf(stderr, "Wrote %d bytes of audio data\n", written);

#endif

}

static Uint8 *

OBSD_GetAudioBuf(_THIS)

{

    return (mixbuf);

}

static void

OBSD_CloseAudio(_THIS)

{

    if (mixbuf != NULL) {

        SDL_FreeAudioMem(mixbuf);

        mixbuf = NULL;

    }

    if (audio_fd >= 0) {

        close(audio_fd);

        audio_fd = -1;

    }

}

#ifdef DEBUG_AUDIO

void

OBSD_Status(_THIS)

{

    audio_info_t info;

    if (ioctl(audio_fd, AUDIO_GETINFO, &info) < 0) {

        fprintf(stderr, "AUDIO_GETINFO failed.\n");

        return;

    }

    fprintf(stderr, "\n"

            "[play/record info]\n"

            "buffer size	:   %d bytes\n"

            "sample rate	:   %i Hz\n"

            "channels	:   %i\n"

            "precision	:   %i-bit\n"

            "encoding	:   0x%x\n"

            "seek		:   %i\n"

            "sample count	:   %i\n"

            "EOF count	:   %i\n"

            "paused		:   %s\n"

            "error occured	:   %s\n"

            "waiting		:   %s\n"

            "active		:   %s\n"

            "",

            info.

            play.

            buffer_size,

            info.

            play.

            sample_rate,

            info.

            play.

            channels,

            info.

            play.

            precision,

            info.

            play.

            encoding,

            info.

            play.

            seek,

            info.

            play.

            samples,

            info.

            play.

            eof,

            info.

            play.

            pause

            ?

            "yes"

            :

            "no",

            info.

            play.

            error

            ?

            "yes"

            :

            "no",

            info.

            play.waiting ? "yes" : "no", info.play.active ? "yes" : "no");

    fprintf(stderr, "\n"

            "[audio info]\n"

            "monitor_gain	:   %i\n"

            "hw block size	:   %d bytes\n"

            "hi watermark	:   %i\n"

            "lo watermark	:   %i\n"

            "audio mode	:   %s\n"

            "",

            info.monitor_gain,

            info.blocksize,

            info.hiwat, info.lowat,

            (info.mode == AUMODE_PLAY) ? "PLAY"

            : (info.mode = AUMODE_RECORD) ? "RECORD"

            : (info.mode == AUMODE_PLAY_ALL ? "PLAY_ALL" : "?"));

}

#endif /* DEBUG_AUDIO */

static int

OBSD_OpenAudio(_THIS, SDL_AudioSpec * spec)

{

    char audiodev[64];

    audio_info_t info;

    AUDIO_INITINFO(&info);

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

    SDL_CalculateAudioSpec(spec);

#ifdef USE_TIMER_SYNC

    frame_ticks = 0.0;

#endif

    /* Open the audio device */

    audio_fd = SDL_OpenAudioPath(audiodev, sizeof(audiodev), OPEN_FLAGS, 0);

    if (audio_fd < 0) {

        SDL_SetError("Couldn't open %s: %s", audiodev, strerror(errno));

        return (-1);

    }

    /* Set to play mode */

    info.mode = AUMODE_PLAY;

    if (ioctl(audio_fd, AUDIO_SETINFO, &info) < 0) {

        SDL_SetError("Couldn't put device into play mode");

        return (-1);

    }

    mixbuf = NULL;

    AUDIO_INITINFO(&info);

    for (format = SDL_FirstAudioFormat(spec->format);

         format; format = SDL_NextAudioFormat()) {

        switch (format) {

        case AUDIO_U8:

            info.play.encoding = AUDIO_ENCODING_ULINEAR;

            info.play.precision = 8;

            break;

        case AUDIO_S8:

            info.play.encoding = AUDIO_ENCODING_SLINEAR;

            info.play.precision = 8;

            break;

        case AUDIO_S16LSB:

            info.play.encoding = AUDIO_ENCODING_SLINEAR_LE;

            info.play.precision = 16;

            break;

        case AUDIO_S16MSB:

            info.play.encoding = AUDIO_ENCODING_SLINEAR_BE;

            info.play.precision = 16;

            break;

        case AUDIO_U16LSB:

            info.play.encoding = AUDIO_ENCODING_ULINEAR_LE;

            info.play.precision = 16;

            break;

        case AUDIO_U16MSB:

            info.play.encoding = AUDIO_ENCODING_ULINEAR_BE;

            info.play.precision = 16;

            break;

        default:

            continue;

        }

        if (ioctl(audio_fd, AUDIO_SETINFO, &info) == 0)

            break;

    }

    if (!format) {

        SDL_SetError("No supported encoding for 0x%x", spec->format);

        return (-1);

    }

    spec->format = format;

    AUDIO_INITINFO(&info);

    info.play.channels = spec->channels;

    if (ioctl(audio_fd, AUDIO_SETINFO, &info) == -1)

        spec->channels = 1;

    AUDIO_INITINFO(&info);

    info.play.sample_rate = spec->freq;

    info.blocksize = spec->size;

    info.hiwat = 5;

    info.lowat = 3;

    (void) ioctl(audio_fd, AUDIO_SETINFO, &info);

    (void) ioctl(audio_fd, AUDIO_GETINFO, &info);

    spec->freq = info.play.sample_rate;

    /* Allocate mixing buffer */

    mixlen = spec->size;

    mixbuf = (Uint8 *) SDL_AllocAudioMem(mixlen);

    if (mixbuf == NULL) {

        return (-1);

    }

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

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

    parent = getpid();

#ifdef DEBUG_AUDIO

    OBSD_Status(this);

#endif

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

    return (0);

}

/* vi: set ts=4 sw=4 expandtab: */