/*

     SDL - Simple DirectMedia Layer

     Copyright (C) 1997-2006 Sam Lantinga

     This library is 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

     This driver was written by:

     Erik Inge Bolsų

     knan@mo.himolde.no

 */

 #include "SDL_config.h"

 /* Allow access to a raw mixing buffer */

 #include <signal.h>

 #include <unistd.h>

 #include "SDL_timer.h"

 #include "SDL_audio.h"

 #include "../SDL_audiomem.h"

 #include "../SDL_audio_c.h"

 #include "SDL_nasaudio.h"

 /* The tag name used by artsc audio */

 #define NAS_DRIVER_NAME         "nas"

 static struct SDL_PrivateAudioData *this2 = NULL;

 /* Audio driver functions */

 static int NAS_OpenAudio(_THIS, SDL_AudioSpec * spec);

 static void NAS_WaitAudio(_THIS);

 static void NAS_PlayAudio(_THIS);

 static Uint8 *NAS_GetAudioBuf(_THIS);

 static void NAS_CloseAudio(_THIS);

 /* Audio driver bootstrap functions */

 static int

 Audio_Available(void)

 {

     AuServer *aud = AuOpenServer("", 0, NULL, 0, NULL, NULL);

     if (!aud)

         return 0;

     AuCloseServer(aud);

     return 1;

 }

 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));

     /* Set the function pointers */

     this->OpenAudio = NAS_OpenAudio;

     this->WaitAudio = NAS_WaitAudio;

     this->PlayAudio = NAS_PlayAudio;

     this->GetAudioBuf = NAS_GetAudioBuf;

     this->CloseAudio = NAS_CloseAudio;

     this->free = Audio_DeleteDevice;

     return this;

 }

 AudioBootStrap NAS_bootstrap = {

     NAS_DRIVER_NAME, "Network Audio System",

     Audio_Available, Audio_CreateDevice, 0

 };

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

 static void

 NAS_WaitAudio(_THIS)

 {

     while (this->hidden->buf_free < this->hidden->mixlen) {

         AuEvent ev;

         AuNextEvent(this->hidden->aud, AuTrue, &ev);

         AuDispatchEvent(this->hidden->aud, &ev);

     }

 }

 static void

 NAS_PlayAudio(_THIS)

 {

     while (this->hidden->mixlen > this->hidden->buf_free) {     /* We think the buffer is full? Yikes! Ask the server for events,

                                                                    in the hope that some of them is LowWater events telling us more

                                                                    of the buffer is free now than what we think. */

         AuEvent ev;

         AuNextEvent(this->hidden->aud, AuTrue, &ev);

         AuDispatchEvent(this->hidden->aud, &ev);

     }

     this->hidden->buf_free -= this->hidden->mixlen;

     /* Write the audio data */

     AuWriteElement(this->hidden->aud, this->hidden->flow, 0,

                    this->hidden->mixlen, this->hidden->mixbuf, AuFalse, NULL);

     this->hidden->written += this->hidden->mixlen;

 #ifdef DEBUG_AUDIO

     fprintf(stderr, "Wrote %d bytes of audio data\n", this->hidden->mixlen);

 #endif

 }

 static Uint8 *

 NAS_GetAudioBuf(_THIS)

 {

     return (this->hidden->mixbuf);

 }

 static void

 NAS_CloseAudio(_THIS)

 {

     if (this->hidden->mixbuf != NULL) {

         SDL_FreeAudioMem(this->hidden->mixbuf);

         this->hidden->mixbuf = NULL;

     }

     if (this->hidden->aud) {

         AuCloseServer(this->hidden->aud);

         this->hidden->aud = 0;

     }

 }

 static unsigned char

 sdlformat_to_auformat(unsigned int fmt)

 {

     switch (fmt) {

     case AUDIO_U8:

         return AuFormatLinearUnsigned8;

     case AUDIO_S8:

         return AuFormatLinearSigned8;

     case AUDIO_U16LSB:

         return AuFormatLinearUnsigned16LSB;

     case AUDIO_U16MSB:

         return AuFormatLinearUnsigned16MSB;

     case AUDIO_S16LSB:

         return AuFormatLinearSigned16LSB;

     case AUDIO_S16MSB:

         return AuFormatLinearSigned16MSB;

     }

     return AuNone;

 }

 static AuBool

 event_handler(AuServer * aud, AuEvent * ev, AuEventHandlerRec * hnd)

 {

     switch (ev->type) {

     case AuEventTypeElementNotify:

         {

             AuElementNotifyEvent *event = (AuElementNotifyEvent *) ev;

             switch (event->kind) {

             case AuElementNotifyKindLowWater:

                 if (this2->buf_free >= 0) {

                     this2->really += event->num_bytes;

                     gettimeofday(&this2->last_tv, 0);

                     this2->buf_free += event->num_bytes;

                 } else {

                     this2->buf_free = event->num_bytes;

                 }

                 break;

             case AuElementNotifyKindState:

                 switch (event->cur_state) {

                 case AuStatePause:

                     if (event->reason != AuReasonUser) {

                         if (this2->buf_free >= 0) {

                             this2->really += event->num_bytes;

                             gettimeofday(&this2->last_tv, 0);

                             this2->buf_free += event->num_bytes;

                         } else {

                             this2->buf_free = event->num_bytes;

                         }

                     }

                     break;

                 }

             }

         }

     }

     return AuTrue;

 }

 static AuDeviceID

 find_device(_THIS, int nch)

 {

     int i;

     for (i = 0; i < AuServerNumDevices(this->hidden->aud); i++) {

         if ((AuDeviceKind(AuServerDevice(this->hidden->aud, i)) ==

              AuComponentKindPhysicalOutput) &&

             AuDeviceNumTracks(AuServerDevice(this->hidden->aud, i)) == nch) {

             return AuDeviceIdentifier(AuServerDevice(this->hidden->aud, i));

         }

     }

     return AuNone;

 }

 static int

 NAS_OpenAudio(_THIS, SDL_AudioSpec * spec)

 {

     AuElement elms[3];

     int buffer_size;

     SDL_AudioFormat test_format, format;

     this->hidden->mixbuf = NULL;

     /* Try for a closest match on audio format */

     format = 0;

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

          !format && test_format;) {

         format = sdlformat_to_auformat(test_format);

         if (format == AuNone) {

             test_format = SDL_NextAudioFormat();

         }

     }

     if (format == 0) {

         SDL_SetError("Couldn't find any hardware audio formats");

         return (-1);

     }

     spec->format = test_format;

     this->hidden->aud = AuOpenServer("", 0, NULL, 0, NULL, NULL);

     if (this->hidden->aud == 0) {

         SDL_SetError("Couldn't open connection to NAS server");

         return (-1);

     }

     this->hidden->dev = find_device(this, spec->channels);

     if ((this->hidden->dev == AuNone)

         || (!(this->hidden->flow = AuCreateFlow(this->hidden->aud, NULL)))) {

         AuCloseServer(this->hidden->aud);

         this->hidden->aud = 0;

         SDL_SetError("Couldn't find a fitting playback device on NAS server");

         return (-1);

     }

     buffer_size = spec->freq;

     if (buffer_size < 4096)

         buffer_size = 4096;

     if (buffer_size > 32768)

         buffer_size = 32768;    /* So that the buffer won't get unmanageably big. */

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

     SDL_CalculateAudioSpec(spec);

     this2 = this->hidden;

     AuMakeElementImportClient(elms, spec->freq, format, spec->channels,

                               AuTrue, buffer_size, buffer_size / 4, 0, NULL);

     AuMakeElementExportDevice(elms + 1, 0, this->hidden->dev, spec->freq,

                               AuUnlimitedSamples, 0, NULL);

     AuSetElements(this->hidden->aud, this->hidden->flow, AuTrue, 2, elms,

                   NULL);

     AuRegisterEventHandler(this->hidden->aud, AuEventHandlerIDMask, 0,

                            this->hidden->flow, event_handler,

                            (AuPointer) NULL);

     AuStartFlow(this->hidden->aud, this->hidden->flow, NULL);

     /* Allocate mixing buffer */

     this->hidden->mixlen = spec->size;

     this->hidden->mixbuf = (Uint8 *) SDL_AllocAudioMem(this->hidden->mixlen);

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

         return (-1);

     }

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

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

     this->hidden->parent = getpid();

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

     return (0);

 }

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