#+title: Simulated Sense of Hearing

 #+author: Robert McIntyre

 #+email: rlm@mit.edu

 #+description: Simulating multiple listeners and the sense of hearing in jMonkeyEngine3

 #+keywords: simulated hearing, openal, clojure, jMonkeyEngine3, LWJGL, AI

 #+SETUPFILE: ../../aurellem/org/setup.org

 #+INCLUDE: ../../aurellem/org/level-0.org

 #+BABEL: :exports both :noweb yes :cache no :mkdirp yes

 

 

 

 

 * Hearing

 

 I want to be able to place ears in a similiar manner to how I place

 the eyes.  I want to be able to place ears in a unique spatial

 position, and recieve as output at every tick the FFT of whatever

 signals are happening at that point.

 

 Hearing is one of the more difficult senses to simulate, because there

 is less support for obtaining the actual sound data that is processed

 by jMonkeyEngine3.

 

 jMonkeyEngine's sound system works as follows:

 

  - jMonkeyEngine uese the =AppSettings= for the particular application

    to determine what sort of =AudioRenderer= should be used.

  - although some support is provided for multiple AudioRendering

    backends, jMonkeyEngine at the time of this writing will either

    pick no AudioRender at all, or the =LwjglAudioRenderer=

  - jMonkeyEngine tries to figure out what sort of system you're

    running and extracts the appropiate native libraries.

  - the =LwjglAudioRenderer= uses the [[http://lwjgl.org/][=LWJGL=]] (lightweight java game

    library) bindings to interface with a C library called [[http://kcat.strangesoft.net/openal.html][=OpenAL=]]

  - =OpenAL= calculates the 3D sound localization and feeds a stream of

    sound to any of various sound output devices with which it knows

    how to communicate.

 

 A consequence of this is that there's no way to access the actual

 sound data produced by =OpenAL=.  Even worse, =OpanAL= only supports

 one /listener/, which normally isn't a problem for games, but becomes

 a problem when trying to make multiple AI creatures that can each hear

 the world from a different perspective.

 

 To make many AI creatures in jMonkeyEngine that can each hear the

 world from their own perspective, it is necessary to go all the way

 back to =OpenAL= and implement support for simulated hearing there.

 

 ** =OpenAL= Devices

    

 =OpenAL= goes to great lengths to support many different systems, all

 with different sound capabilities and interfaces.  It acomplishes this

 difficult task by providing code for many different sound backends in

 pseudo-objects called /Devices/.  There's a device for the Linux Open

 Sound System and the Advanced Linxu Sound Architechture, there's one

 for Direct Sound on Windows, there's even one for Solaris. =OpenAL=

 solves the problem of platform independence by providing all these

 Devices.

 

 Wrapper libraries such as LWJGL are free to examine the system on

 which they are running and then select an appropiate device for that

 system. 

 

 There are also a few "special" devices that don't interface with any

 particular system.  These include the Null Device, which doesn't do

 anything, and the Wave Device, which writes whatever sound it recieves

 to a file, if everything has been set up correctly when configuring

 =OpenAL=.

 

 Actual mixing of the sound data happens in the Devices, and they are

 the only point in the sound rendering process where this data is

 available. 

 

 Therefore, in order to support multiple listeners, and get the sound

 data in a form that the AIs can use, it is necessary to create a new

 Device, which supports this features.

 

 

 ** The Send Device

 Adding a device to OpenAL is rather tricky -- there are five separate

 files in the =OpenAL= source tree that must be modified to do so. I've

 documented this process [[./add-new-device.org][here]] for anyone who is interested.

 

 #+srcname: send

 #+begin_src C

 #include "config.h"

 #include <stdlib.h>

 #include "alMain.h"

 #include "AL/al.h"

 #include "AL/alc.h"

 #include "alSource.h"

 #include <jni.h>

 

 //////////////////// Summary

 

 struct send_data;

 struct context_data;

 

 static void addContext(ALCdevice *, ALCcontext *);

 static void syncContexts(ALCcontext *master, ALCcontext *slave);

 static void syncSources(ALsource *master, ALsource *slave, 

 			ALCcontext *masterCtx, ALCcontext *slaveCtx);

 

 static void syncSourcei(ALuint master, ALuint slave,

 			ALCcontext *masterCtx, ALCcontext *ctx2, ALenum param);

 static void syncSourcef(ALuint master, ALuint slave,

 			ALCcontext *masterCtx, ALCcontext *ctx2, ALenum param);

 static void syncSource3f(ALuint master, ALuint slave,

 			ALCcontext *masterCtx, ALCcontext *ctx2, ALenum param);

 

 static void swapInContext(ALCdevice *, struct context_data *);

 static void saveContext(ALCdevice *, struct context_data *);

 static void limitContext(ALCdevice *, ALCcontext *);

 static void unLimitContext(ALCdevice *);

 

 static void init(ALCdevice *);

 static void renderData(ALCdevice *, int samples);

 

 #define UNUSED(x)  (void)(x)

 

 ////////////////////  State

 

 typedef struct context_data {

   ALfloat ClickRemoval[MAXCHANNELS];

   ALfloat PendingClicks[MAXCHANNELS];

   ALvoid *renderBuffer;

   ALCcontext *ctx;

 } context_data;

 

 typedef struct send_data {

   ALuint size;

   context_data **contexts;

   ALuint numContexts;

   ALuint maxContexts;

 } send_data;

 

 

 

 ////////////////////  Context Creation / Synchronization

 

 #define _MAKE_SYNC(NAME, INIT_EXPR, GET_EXPR, SET_EXPR)	\

   void NAME (ALuint sourceID1, ALuint sourceID2,	\

 	     ALCcontext *ctx1, ALCcontext *ctx2,	\

 	     ALenum param){				\

     INIT_EXPR;						\

     ALCcontext *current = alcGetCurrentContext();	\

     alcMakeContextCurrent(ctx1);			\

     GET_EXPR;						\

     alcMakeContextCurrent(ctx2);			\

     SET_EXPR;						\

     alcMakeContextCurrent(current);			\

   }

   

 #define MAKE_SYNC(NAME, TYPE, GET, SET)			\

   _MAKE_SYNC(NAME,					\

 	     TYPE value,				\

              GET(sourceID1, param, &value),		\

              SET(sourceID2, param, value))

   

 #define MAKE_SYNC3(NAME, TYPE, GET, SET)				\

   _MAKE_SYNC(NAME,							\

 	     TYPE value1; TYPE value2; TYPE value3;,			\

 	     GET(sourceID1, param, &value1, &value2, &value3),		\

 	     SET(sourceID2, param,  value1,  value2,  value3))

 

 MAKE_SYNC( syncSourcei,  ALint,   alGetSourcei,  alSourcei);

 MAKE_SYNC( syncSourcef,  ALfloat, alGetSourcef,  alSourcef);

 MAKE_SYNC3(syncSource3i, ALint,   alGetSource3i, alSource3i);

 MAKE_SYNC3(syncSource3f, ALfloat, alGetSource3f, alSource3f);

   

 void syncSources(ALsource *masterSource, ALsource *slaveSource, 

 		 ALCcontext *masterCtx, ALCcontext *slaveCtx){

   ALuint master = masterSource->source;

   ALuint slave = slaveSource->source;

   ALCcontext *current = alcGetCurrentContext();

 

   syncSourcef(master,slave,masterCtx,slaveCtx,AL_PITCH);

   syncSourcef(master,slave,masterCtx,slaveCtx,AL_GAIN);

   syncSourcef(master,slave,masterCtx,slaveCtx,AL_MAX_DISTANCE);

   syncSourcef(master,slave,masterCtx,slaveCtx,AL_ROLLOFF_FACTOR);

   syncSourcef(master,slave,masterCtx,slaveCtx,AL_REFERENCE_DISTANCE);

   syncSourcef(master,slave,masterCtx,slaveCtx,AL_MIN_GAIN);

   syncSourcef(master,slave,masterCtx,slaveCtx,AL_MAX_GAIN);

   syncSourcef(master,slave,masterCtx,slaveCtx,AL_CONE_OUTER_GAIN);

   syncSourcef(master,slave,masterCtx,slaveCtx,AL_CONE_INNER_ANGLE);

   syncSourcef(master,slave,masterCtx,slaveCtx,AL_CONE_OUTER_ANGLE);

   syncSourcef(master,slave,masterCtx,slaveCtx,AL_SEC_OFFSET);

   syncSourcef(master,slave,masterCtx,slaveCtx,AL_SAMPLE_OFFSET);

   syncSourcef(master,slave,masterCtx,slaveCtx,AL_BYTE_OFFSET);

     

   syncSource3f(master,slave,masterCtx,slaveCtx,AL_POSITION);

   syncSource3f(master,slave,masterCtx,slaveCtx,AL_VELOCITY);

   syncSource3f(master,slave,masterCtx,slaveCtx,AL_DIRECTION);

   

   syncSourcei(master,slave,masterCtx,slaveCtx,AL_SOURCE_RELATIVE);

   syncSourcei(master,slave,masterCtx,slaveCtx,AL_LOOPING);

 

   alcMakeContextCurrent(masterCtx);

   ALint source_type;

   alGetSourcei(master, AL_SOURCE_TYPE, &source_type);

 

   // Only static sources are currently synchronized! 

   if (AL_STATIC == source_type){

     ALint master_buffer;

     ALint slave_buffer;

     alGetSourcei(master, AL_BUFFER, &master_buffer);

     alcMakeContextCurrent(slaveCtx);

     alGetSourcei(slave, AL_BUFFER, &slave_buffer);

     if (master_buffer != slave_buffer){

       alSourcei(slave, AL_BUFFER, master_buffer);

     }

   }

   

   // Synchronize the state of the two sources.

   alcMakeContextCurrent(masterCtx);

   ALint masterState;

   ALint slaveState;

 

   alGetSourcei(master, AL_SOURCE_STATE, &masterState);

   alcMakeContextCurrent(slaveCtx);

   alGetSourcei(slave, AL_SOURCE_STATE, &slaveState);

 

   if (masterState != slaveState){

     switch (masterState){

     case AL_INITIAL : alSourceRewind(slave); break;

     case AL_PLAYING : alSourcePlay(slave);   break;

     case AL_PAUSED  : alSourcePause(slave);  break;

     case AL_STOPPED : alSourceStop(slave);   break;

     }

   }

   // Restore whatever context was previously active.

   alcMakeContextCurrent(current);

 }

 

 

 void syncContexts(ALCcontext *master, ALCcontext *slave){

   /* If there aren't sufficient sources in slave to mirror 

      the sources in master, create them. */

   ALCcontext *current = alcGetCurrentContext();

 

   UIntMap *masterSourceMap = &(master->SourceMap);

   UIntMap *slaveSourceMap = &(slave->SourceMap);

   ALuint numMasterSources = masterSourceMap->size;

   ALuint numSlaveSources = slaveSourceMap->size;

 

   alcMakeContextCurrent(slave);

   if (numSlaveSources < numMasterSources){

     ALuint numMissingSources = numMasterSources - numSlaveSources;

     ALuint newSources[numMissingSources];

     alGenSources(numMissingSources, newSources);

   }

 

   /* Now, slave is gauranteed to have at least as many sources

      as master.  Sync each source from master to the corresponding

      source in slave. */

   int i;

   for(i = 0; i < masterSourceMap->size; i++){

     syncSources((ALsource*)masterSourceMap->array[i].value,

 		(ALsource*)slaveSourceMap->array[i].value,

 		master, slave);

   }

   alcMakeContextCurrent(current);

 }

 

 static void addContext(ALCdevice *Device, ALCcontext *context){

   send_data *data = (send_data*)Device->ExtraData;

   // expand array if necessary

   if (data->numContexts >= data->maxContexts){

     ALuint newMaxContexts = data->maxContexts*2 + 1;

     data->contexts = realloc(data->contexts, newMaxContexts*sizeof(context_data));

     data->maxContexts = newMaxContexts;

   }

   // create context_data and add it to the main array

   context_data *ctxData;

   ctxData = (context_data*)calloc(1, sizeof(*ctxData));

   ctxData->renderBuffer = 

     malloc(BytesFromDevFmt(Device->FmtType) * 

 	   Device->NumChan * Device->UpdateSize);

   ctxData->ctx = context;

 

   data->contexts[data->numContexts] = ctxData;

   data->numContexts++;

 }

 

 

 ////////////////////  Context Switching 

 

 /* A device brings along with it two pieces of state

  * which have to be swapped in and out with each context.

  */

 static void swapInContext(ALCdevice *Device, context_data *ctxData){

   memcpy(Device->ClickRemoval, ctxData->ClickRemoval, sizeof(ALfloat)*MAXCHANNELS);

   memcpy(Device->PendingClicks, ctxData->PendingClicks, sizeof(ALfloat)*MAXCHANNELS);

 }

 

 static void saveContext(ALCdevice *Device, context_data *ctxData){

   memcpy(ctxData->ClickRemoval, Device->ClickRemoval, sizeof(ALfloat)*MAXCHANNELS);

   memcpy(ctxData->PendingClicks, Device->PendingClicks, sizeof(ALfloat)*MAXCHANNELS);

 }  

 

 static ALCcontext **currentContext;

 static ALuint currentNumContext;

 

 /* By default, all contexts are rendered at once for each call to aluMixData.

  * This function uses the internals of the ALCdecice struct to temporarly 

  * cause aluMixData to only render the chosen context.

  */

 static void limitContext(ALCdevice *Device, ALCcontext *ctx){

   currentContext  = Device->Contexts;

   currentNumContext  = Device->NumContexts;

   Device->Contexts = &ctx;

   Device->NumContexts = 1;

 }

 

 static void unLimitContext(ALCdevice *Device){

   Device->Contexts = currentContext;

   Device->NumContexts = currentNumContext;

 }

 

 

 ////////////////////   Main Device Loop

 

 /* Establish the LWJGL context as the main context, which will

  * be synchronized to all the slave contexts

  */

 static void init(ALCdevice *Device){

   ALCcontext *masterContext = alcGetCurrentContext();

   addContext(Device, masterContext);

 }

 

 

 static void renderData(ALCdevice *Device, int samples){

   if(!Device->Connected){return;}

   send_data *data = (send_data*)Device->ExtraData;

   ALCcontext *current = alcGetCurrentContext();

 

   ALuint i;

   for (i = 1; i < data->numContexts; i++){

     syncContexts(data->contexts[0]->ctx , data->contexts[i]->ctx);

   }

   

   if ((uint) samples > Device->UpdateSize){

     printf("exceeding internal buffer size; dropping samples\n");

     printf("requested %d; available %d\n", samples, Device->UpdateSize);

     samples = (int) Device->UpdateSize;

   }

 

   for (i = 0; i < data->numContexts; i++){

     context_data *ctxData = data->contexts[i];

     ALCcontext *ctx = ctxData->ctx;

     alcMakeContextCurrent(ctx);

     limitContext(Device, ctx);

     swapInContext(Device, ctxData);

     aluMixData(Device, ctxData->renderBuffer, samples);

     saveContext(Device, ctxData);

     unLimitContext(Device);

   }

   alcMakeContextCurrent(current);

 }

 

 

 ////////////////////   JNI Methods

 

 #include "com_aurellem_send_AudioSend.h"

 

 /*

  * Class:     com_aurellem_send_AudioSend

  * Method:    nstep

  * Signature: (JI)V

  */

 JNIEXPORT void JNICALL Java_com_aurellem_send_AudioSend_nstep

 (JNIEnv *env, jclass clazz, jlong device, jint samples){

   UNUSED(env);UNUSED(clazz);UNUSED(device);

   renderData((ALCdevice*)((intptr_t)device), samples);

 }

 

 /*

  * Class:     com_aurellem_send_AudioSend

  * Method:    ngetSamples

  * Signature: (JLjava/nio/ByteBuffer;III)V

  */

 JNIEXPORT void JNICALL Java_com_aurellem_send_AudioSend_ngetSamples

 (JNIEnv *env, jclass clazz, jlong device, jobject buffer, jint position, 

  jint samples, jint n){

   UNUSED(clazz);  

 

   ALvoid *buffer_address = 

     ((ALbyte *)(((char*)(*env)->GetDirectBufferAddress(env, buffer)) + position));

   ALCdevice *recorder = (ALCdevice*) ((intptr_t)device);

   send_data *data = (send_data*)recorder->ExtraData;

   if ((ALuint)n > data->numContexts){return;}

   

   //printf("Want %d samples for listener %d\n", samples, n);

   //printf("Device's format type is %d bytes per sample,\n", 

   //  BytesFromDevFmt(recorder->FmtType));

   //printf("and it has %d channels, making for %d requested bytes\n", 

   //	 recorder->NumChan, 

   //	 BytesFromDevFmt(recorder->FmtType) * recorder->NumChan * samples);

 

   memcpy(buffer_address, data->contexts[n]->renderBuffer, 

 	 BytesFromDevFmt(recorder->FmtType) * recorder->NumChan * samples);

   //samples*sizeof(ALfloat));

 }

 

 /*

  * Class:     com_aurellem_send_AudioSend

  * Method:    naddListener

  * Signature: (J)V

  */

 JNIEXPORT void JNICALL Java_com_aurellem_send_AudioSend_naddListener

 (JNIEnv *env, jclass clazz, jlong device){

   UNUSED(env); UNUSED(clazz);

   //printf("creating new context via naddListener\n");

   ALCdevice *Device = (ALCdevice*) ((intptr_t)device);

   ALCcontext *new = alcCreateContext(Device, NULL);

   addContext(Device, new);

 }

 

 /*

  * Class:     com_aurellem_send_AudioSend

  * Method:    nsetNthListener3f

  * Signature: (IFFFJI)V

  */

 JNIEXPORT void JNICALL Java_com_aurellem_send_AudioSend_nsetNthListener3f

   (JNIEnv *env, jclass clazz, jint param, 

    jfloat v1, jfloat v2, jfloat v3, jlong device, jint contextNum){

   UNUSED(env);UNUSED(clazz);

 

   ALCdevice *Device = (ALCdevice*) ((intptr_t)device);

   send_data *data = (send_data*)Device->ExtraData;

   

   ALCcontext *current = alcGetCurrentContext();

   if ((ALuint)contextNum > data->numContexts){return;}

   alcMakeContextCurrent(data->contexts[contextNum]->ctx);

   alListener3f(param, v1, v2, v3);

   alcMakeContextCurrent(current);

 }

 

 /*

  * Class:     com_aurellem_send_AudioSend

  * Method:    nsetNthListenerf

  * Signature: (IFJI)V

  */

 JNIEXPORT void JNICALL Java_com_aurellem_send_AudioSend_nsetNthListenerf

 (JNIEnv *env, jclass clazz, jint param, jfloat v1, jlong device, 

  jint contextNum){

 

   UNUSED(env);UNUSED(clazz);

   

   ALCdevice *Device = (ALCdevice*) ((intptr_t)device);

   send_data *data = (send_data*)Device->ExtraData;

   

   ALCcontext *current = alcGetCurrentContext();

   if ((ALuint)contextNum > data->numContexts){return;}

   alcMakeContextCurrent(data->contexts[contextNum]->ctx);

   alListenerf(param, v1);

   alcMakeContextCurrent(current);

 }

 

 /*

  * Class:     com_aurellem_send_AudioSend

  * Method:    ninitDevice

  * Signature: (J)V

  */                     

 JNIEXPORT void JNICALL Java_com_aurellem_send_AudioSend_ninitDevice

 (JNIEnv *env, jclass clazz, jlong device){

   UNUSED(env);UNUSED(clazz);

   

   ALCdevice *Device = (ALCdevice*) ((intptr_t)device);

   init(Device);

 

 }

 

 

 /*

  * Class:     com_aurellem_send_AudioSend

  * Method:    ngetAudioFormat

  * Signature: (J)Ljavax/sound/sampled/AudioFormat;

  */

 JNIEXPORT jobject JNICALL Java_com_aurellem_send_AudioSend_ngetAudioFormat

 (JNIEnv *env, jclass clazz, jlong device){

   UNUSED(clazz);

   jclass AudioFormatClass = 

     (*env)->FindClass(env, "javax/sound/sampled/AudioFormat");

   jmethodID AudioFormatConstructor = 

     (*env)->GetMethodID(env, AudioFormatClass, "<init>", "(FIIZZ)V");

   

   ALCdevice *Device = (ALCdevice*) ((intptr_t)device);

 

   //float frequency

 

   int isSigned;

   switch (Device->FmtType)

     {

     case DevFmtUByte: 

     case DevFmtUShort: isSigned = 0; break;  

     default : isSigned = 1;   

     }

   float frequency = Device->Frequency;

   int bitsPerFrame = (8 * BytesFromDevFmt(Device->FmtType));

   int channels = Device->NumChan;

 

 

   //printf("freq = %f, bpf = %d, channels = %d, signed? = %d\n",

   //	 frequency, bitsPerFrame, channels, isSigned);

 

   jobject format = (*env)->

     NewObject(

 	      env,AudioFormatClass,AudioFormatConstructor,

 	      frequency,

 	      bitsPerFrame,

 	      channels,

 	      isSigned,

 	      0);

   return format;

 }

 

 

 

 ////////////////////   Device Initilization / Management

 

 static const ALCchar sendDevice[] = "Multiple Audio Send";

 

 static ALCboolean send_open_playback(ALCdevice *device, 

  const ALCchar *deviceName)

 {

   send_data *data;

   // stop any buffering for stdout, so that I can 

   // see the printf statements in my terminal immediatley

   setbuf(stdout, NULL);

 

   if(!deviceName)

     deviceName = sendDevice;

   else if(strcmp(deviceName, sendDevice) != 0)

     return ALC_FALSE;

   data = (send_data*)calloc(1, sizeof(*data));

   device->szDeviceName = strdup(deviceName);

   device->ExtraData = data;

   return ALC_TRUE;

 }

 

 static void send_close_playback(ALCdevice *device)

 {

   send_data *data = (send_data*)device->ExtraData;

   alcMakeContextCurrent(NULL);

   ALuint i;

   // Destroy all slave contexts. LWJGL will take care of 

   // its own context.

   for (i = 1; i < data->numContexts; i++){

     context_data *ctxData = data->contexts[i];

     alcDestroyContext(ctxData->ctx);

     free(ctxData->renderBuffer);

     free(ctxData);

   }

   free(data);

   device->ExtraData = NULL;

 }

 

 static ALCboolean send_reset_playback(ALCdevice *device)

 {

   SetDefaultWFXChannelOrder(device);

   return ALC_TRUE;

 }

 

 static void send_stop_playback(ALCdevice *Device){

   UNUSED(Device);

 }

 

 static const BackendFuncs send_funcs = {

   send_open_playback,

   send_close_playback,

   send_reset_playback,

   send_stop_playback,

   NULL,

   NULL,  /* These would be filled with functions to    */

   NULL,  /* handle capturing audio if we we into that  */

   NULL,  /* sort of thing...                           */

   NULL,

   NULL

 };

 

 ALCboolean alc_send_init(BackendFuncs *func_list){

   *func_list = send_funcs;

   return ALC_TRUE;

 }

 

 void alc_send_deinit(void){}

 

 void alc_send_probe(enum DevProbe type)

 {

   switch(type)

     {

     case DEVICE_PROBE:

       AppendDeviceList(sendDevice);

       break;

     case ALL_DEVICE_PROBE:

       AppendAllDeviceList(sendDevice);

       break;

     case CAPTURE_DEVICE_PROBE:

       break;

     }

 }

 #+end_src

 

 

 

 

 

 

 

 

 #+srcname: ears

 #+begin_src clojure

 (ns cortex.hearing)

 (use 'cortex.world)

 (use 'cortex.import)

 (use 'clojure.contrib.def)

 (cortex.import/mega-import-jme3)

 (rlm.rlm-commands/help)

 (import java.nio.ByteBuffer)

 (import java.awt.image.BufferedImage)

 (import java.awt.Color)

 (import java.awt.Dimension)

 (import java.awt.Graphics)

 (import java.awt.Graphics2D)

 (import java.awt.event.WindowAdapter)

 (import java.awt.event.WindowEvent)

 (import java.awt.image.BufferedImage)

 (import java.nio.ByteBuffer)

 (import javax.swing.JFrame)

 (import javax.swing.JPanel)

 (import javax.swing.SwingUtilities)

 (import javax.swing.ImageIcon)

 (import javax.swing.JOptionPane)

 (import java.awt.image.ImageObserver)

 

 (import 'com.jme3.capture.SoundProcessor)

 

 

 (defn sound-processor

   "deals with converting ByteBuffers into Arrays of bytes so that the

   continuation functions can be defined in terms of immutable stuff."

   [continuation]

   (proxy [SoundProcessor] []

     (cleanup [])

     (process

       [#^ByteBuffer audioSamples numSamples]

       (no-exceptions

        (let [byte-array (byte-array numSamples)]

 	 (.get audioSamples byte-array 0 numSamples)

 	 (continuation

 	  (vec byte-array)))))))

 

 (defn add-ear 

   "add an ear to the world.  The continuation function will be called

   on the FFT or the sounds which the ear hears in the given

   timeframe. Sound is 3D."

   [world listener continuation]

   (let [renderer (.getAudioRenderer world)]

     (.addListener renderer listener)

     (.registerSoundProcessor renderer listener

 			     (sound-processor continuation))

     listener))

 

 #+end_src

 

 

 

 #+srcname: test-hearing

 #+begin_src clojure :results silent

 (ns test.hearing)

 (use 'cortex.world)

 (use 'cortex.import)

 (use 'clojure.contrib.def)

 (use 'body.ear)

 (cortex.import/mega-import-jme3)

 (rlm.rlm-commands/help)

 

 (defn setup-fn [world]

   (let [listener (Listener.)]

     (add-ear world listener #(println (nth % 0)))))

   

 (defn play-sound [node world value]

   (if (not value)

     (do

       (.playSource (.getAudioRenderer world) node))))

 

 (defn test-world []

   (let [node1 (AudioNode. (asset-manager) "Sounds/pure.wav" false false)]

     (world

      (Node.)

      {"key-space" (partial play-sound node1)}

      setup-fn

      no-op

      )))

     

 

 #+end_src

 

 

 

 * Example

 

 * COMMENT Code Generation

 

 #+begin_src clojure :tangle ../../cortex/src/cortex/hearing.clj

 <<ears>>

 #+end_src

 

 #+begin_src clojure :tangle ../../cortex/src/test/hearing.clj

 <<test-hearing>>

 #+end_src

 

 

 #+begin_src C :tangle ../Alc/backends/send.c

 <<send>>

 #+end_src