/**

  * $Id$

  * 

  * The darwin core-audio audio driver

  *

  * Copyright (c) 2008 Nathan Keynes.

  *

  * This program is free software; you can redistribute it and/or modify

  * it under the terms of the GNU General Public License as published by

  * the Free Software Foundation; either version 2 of the License, or

  * (at your option) any later version.

  *

  * This program 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 General Public License for more details.

  */

 #include <stdio.h>

 #include <unistd.h>

 #include <CoreAudio/CoreAudio.h>

 #include "aica/audio.h"

 #include "lxdream.h"

 #define BUFFER_SIZE (sizeof(float)*2*2205)

 static AudioDeviceID output_device;

 static volatile audio_buffer_t output_buffer = NULL;

 static uint32_t buffer_size;

 static OSStatus audio_osx_callback( AudioDeviceID inDevice,

                              const AudioTimeStamp *inNow,

                              const AudioBufferList *inInputData,

                              const AudioTimeStamp *inInputTime,

                              AudioBufferList *outOutputData,

                              const AudioTimeStamp *inOutputTime,

                              void *inClientData)

 {

     char *output = outOutputData->mBuffers[0].mData;

     int data_requested = buffer_size;

     while( output_buffer != NULL && data_requested > 0 ) {

         int copysize = output_buffer->length - output_buffer->posn;

         if( copysize > data_requested ) {

             copysize = data_requested;

         }

         memcpy( output, &output_buffer->data[output_buffer->posn], copysize );

         output += copysize;

         data_requested -= copysize;

         output_buffer->posn += copysize;

         if( output_buffer->posn >= output_buffer->length ) {

             output_buffer = audio_next_read_buffer();

         }

     }

     if( data_requested > 0 ) {

         memset( output, 0, data_requested );

     }

     return noErr;

 }

 static gboolean audio_osx_shutdown()

 {

     AudioDeviceStop( output_device, audio_osx_callback );

     AudioDeviceRemoveIOProc( output_device, audio_osx_callback );

     return TRUE;

 }

 static gboolean audio_osx_init()

 {

     UInt32 size = sizeof(output_device);

     AudioStreamBasicDescription outputDesc;

     UInt32 outputDescSize = sizeof(outputDesc);

     if( AudioHardwareGetProperty(kAudioHardwarePropertyDefaultOutputDevice,

             &size, &output_device) != noErr ||

             output_device == kAudioDeviceUnknown ) {

         return FALSE;

     }

     if( AudioDeviceGetProperty( output_device, 1, 0, kAudioDevicePropertyStreamFormat,

             &outputDescSize, &outputDesc ) != noErr ) {

         return FALSE;

     }

     buffer_size = BUFFER_SIZE;

     if( AudioDeviceSetProperty( output_device, 0, 0, 0, kAudioDevicePropertyBufferSize,

             sizeof(buffer_size), &buffer_size ) != noErr ) {

         return FALSE;

     }

     AudioDeviceAddIOProc( output_device, audio_osx_callback, NULL );    

     return TRUE;

 }

 static gboolean audio_osx_process_buffer( audio_buffer_t buffer )

 {

     if( output_buffer == NULL ) {

         output_buffer = buffer;

         output_buffer->posn = 0;

         AudioDeviceStart(output_device, audio_osx_callback);

     }

     return FALSE;

 }

 static void audio_osx_start()

 {

     if( output_buffer != NULL ) {

         AudioDeviceStart(output_device, audio_osx_callback);

     }

 }

 static void audio_osx_stop()

 {

     AudioDeviceStop( output_device, audio_osx_callback );

 }

 static struct audio_driver audio_osx_driver = { 

         "osx",

         N_("OS X CoreAudio system driver"), 

         1, // Preferred on OS X

         DEFAULT_SAMPLE_RATE,

         AUDIO_FMT_FLOATST,

         audio_osx_init,

         audio_osx_start, 

         audio_osx_process_buffer,

         audio_osx_stop,

         audio_osx_shutdown};

 AUDIO_DRIVER( "osx", audio_osx_driver );