1.1 --- a/org/ear.org	Fri Feb 03 06:40:59 2012 -0700
     1.2 +++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.3 @@ -1,952 +0,0 @@
     1.4 -#+title: Simulated Sense of Hearing
     1.5 -#+author: Robert McIntyre
     1.6 -#+email: rlm@mit.edu
     1.7 -#+description: Simulating multiple listeners and the sense of hearing in jMonkeyEngine3
     1.8 -#+keywords: simulated hearing, openal, clojure, jMonkeyEngine3, LWJGL, AI
     1.9 -#+SETUPFILE: ../../aurellem/org/setup.org
    1.10 -#+INCLUDE: ../../aurellem/org/level-0.org
    1.11 -#+BABEL: :exports both :noweb yes :cache no :mkdirp yes
    1.12 -
    1.13 -* Hearing
    1.14 -
    1.15 -I want to be able to place ears in a similar manner to how I place
    1.16 -the eyes.  I want to be able to place ears in a unique spatial
    1.17 -position, and receive as output at every tick the F.F.T. of whatever
    1.18 -signals are happening at that point.
    1.19 -
    1.20 -Hearing is one of the more difficult senses to simulate, because there
    1.21 -is less support for obtaining the actual sound data that is processed
    1.22 -by jMonkeyEngine3.
    1.23 -
    1.24 -jMonkeyEngine's sound system works as follows:
    1.25 -
    1.26 - - jMonkeyEngine uses the =AppSettings= for the particular application
    1.27 -   to determine what sort of =AudioRenderer= should be used.
    1.28 - - although some support is provided for multiple AudioRendering
    1.29 -   backends, jMonkeyEngine at the time of this writing will either
    1.30 -   pick no AudioRenderer at all, or the =LwjglAudioRenderer=
    1.31 - - jMonkeyEngine tries to figure out what sort of system you're
    1.32 -   running and extracts the appropriate native libraries.
    1.33 - - the =LwjglAudioRenderer= uses the [[http://lwjgl.org/][=LWJGL=]] (LightWeight Java Game
    1.34 -   Library) bindings to interface with a C library called [[http://kcat.strangesoft.net/openal.html][=OpenAL=]]
    1.35 - - =OpenAL= calculates the 3D sound localization and feeds a stream of
    1.36 -   sound to any of various sound output devices with which it knows
    1.37 -   how to communicate.
    1.38 -
    1.39 -A consequence of this is that there's no way to access the actual
    1.40 -sound data produced by =OpenAL=.  Even worse, =OpenAL= only supports
    1.41 -one /listener/, which normally isn't a problem for games, but becomes
    1.42 -a problem when trying to make multiple AI creatures that can each hear
    1.43 -the world from a different perspective.
    1.44 -
    1.45 -To make many AI creatures in jMonkeyEngine that can each hear the
    1.46 -world from their own perspective, it is necessary to go all the way
    1.47 -back to =OpenAL= and implement support for simulated hearing there.
    1.48 -
    1.49 -* Extending =OpenAL=
    1.50 -** =OpenAL= Devices
    1.51 -   
    1.52 -=OpenAL= goes to great lengths to support many different systems, all
    1.53 -with different sound capabilities and interfaces.  It accomplishes this
    1.54 -difficult task by providing code for many different sound backends in
    1.55 -pseudo-objects called /Devices/.  There's a device for the Linux Open
    1.56 -Sound System and the Advanced Linux Sound Architecture, there's one
    1.57 -for Direct Sound on Windows, there's even one for Solaris. =OpenAL=
    1.58 -solves the problem of platform independence by providing all these
    1.59 -Devices.
    1.60 -
    1.61 -Wrapper libraries such as LWJGL are free to examine the system on
    1.62 -which they are running and then select an appropriate device for that
    1.63 -system. 
    1.64 -
    1.65 -There are also a few "special" devices that don't interface with any
    1.66 -particular system.  These include the Null Device, which doesn't do
    1.67 -anything, and the Wave Device, which writes whatever sound it receives
    1.68 -to a file, if everything has been set up correctly when configuring
    1.69 -=OpenAL=.
    1.70 -
    1.71 -Actual mixing of the sound data happens in the Devices, and they are
    1.72 -the only point in the sound rendering process where this data is
    1.73 -available. 
    1.74 -
    1.75 -Therefore, in order to support multiple listeners, and get the sound
    1.76 -data in a form that the AIs can use, it is necessary to create a new
    1.77 -Device, which supports this features.
    1.78 -
    1.79 -** The Send Device
    1.80 -Adding a device to OpenAL is rather tricky -- there are five separate
    1.81 -files in the =OpenAL= source tree that must be modified to do so. I've
    1.82 -documented this process [[./add-new-device.org][here]] for anyone who is interested.
    1.83 -
    1.84 -
    1.85 -Onward to that actual Device!
    1.86 -
    1.87 -again, my objectives are:
    1.88 -
    1.89 - - Support Multiple Listeners from jMonkeyEngine3
    1.90 - - Get access to the rendered sound data for further processing from
    1.91 -   clojure.
    1.92 -
    1.93 -** =send.c=
    1.94 -
    1.95 -** Header
    1.96 -#+name: send-header
    1.97 -#+begin_src C
    1.98 -#include "config.h"
    1.99 -#include <stdlib.h>
   1.100 -#include "alMain.h"
   1.101 -#include "AL/al.h"
   1.102 -#include "AL/alc.h"
   1.103 -#include "alSource.h"
   1.104 -#include <jni.h>
   1.105 -
   1.106 -//////////////////// Summary
   1.107 -
   1.108 -struct send_data;
   1.109 -struct context_data;
   1.110 -
   1.111 -static void addContext(ALCdevice *, ALCcontext *);
   1.112 -static void syncContexts(ALCcontext *master, ALCcontext *slave);
   1.113 -static void syncSources(ALsource *master, ALsource *slave, 
   1.114 -			ALCcontext *masterCtx, ALCcontext *slaveCtx);
   1.115 -
   1.116 -static void syncSourcei(ALuint master, ALuint slave,
   1.117 -			ALCcontext *masterCtx, ALCcontext *ctx2, ALenum param);
   1.118 -static void syncSourcef(ALuint master, ALuint slave,
   1.119 -			ALCcontext *masterCtx, ALCcontext *ctx2, ALenum param);
   1.120 -static void syncSource3f(ALuint master, ALuint slave,
   1.121 -			ALCcontext *masterCtx, ALCcontext *ctx2, ALenum param);
   1.122 -
   1.123 -static void swapInContext(ALCdevice *, struct context_data *);
   1.124 -static void saveContext(ALCdevice *, struct context_data *);
   1.125 -static void limitContext(ALCdevice *, ALCcontext *);
   1.126 -static void unLimitContext(ALCdevice *);
   1.127 -
   1.128 -static void init(ALCdevice *);
   1.129 -static void renderData(ALCdevice *, int samples);
   1.130 -
   1.131 -#define UNUSED(x)  (void)(x)
   1.132 -#+end_src
   1.133 -
   1.134 -The main idea behind the Send device is to take advantage of the fact
   1.135 -that LWJGL only manages one /context/ when using OpenAL.  A /context/
   1.136 -is like a container that holds samples and keeps track of where the
   1.137 -listener is.  In order to support multiple listeners, the Send device
   1.138 -identifies the LWJGL context as the master context, and creates any
   1.139 -number of slave contexts to represent additional listeners.  Every
   1.140 -time the device renders sound, it synchronizes every source from the
   1.141 -master LWJGL context to the slave contexts.  Then, it renders each
   1.142 -context separately, using a different listener for each one.  The
   1.143 -rendered sound is made available via JNI to jMonkeyEngine.
   1.144 -
   1.145 -To recap, the process is: 
   1.146 - - Set the LWJGL context as "master" in the =init()= method.
   1.147 - - Create any number of additional contexts via =addContext()=
   1.148 - - At every call to =renderData()= sync the master context with the
   1.149 -   slave contexts with =syncContexts()=
   1.150 - - =syncContexts()= calls =syncSources()= to sync all the sources
   1.151 -   which are in the master context.
   1.152 - - =limitContext()= and =unLimitContext()= make it possible to render
   1.153 -   only one context at a time.
   1.154 -
   1.155 -** Necessary State
   1.156 -#+name: send-state
   1.157 -#+begin_src C
   1.158 -////////////////////  State
   1.159 -
   1.160 -typedef struct context_data {
   1.161 -  ALfloat ClickRemoval[MAXCHANNELS];
   1.162 -  ALfloat PendingClicks[MAXCHANNELS];
   1.163 -  ALvoid *renderBuffer;
   1.164 -  ALCcontext *ctx;
   1.165 -} context_data;
   1.166 -
   1.167 -typedef struct send_data {
   1.168 -  ALuint size;
   1.169 -  context_data **contexts;
   1.170 -  ALuint numContexts;
   1.171 -  ALuint maxContexts;
   1.172 -} send_data;
   1.173 -#+end_src
   1.174 -
   1.175 -Switching between contexts is not the normal operation of a Device,
   1.176 -and one of the problems with doing so is that a Device normally keeps
   1.177 -around a few pieces of state such as the =ClickRemoval= array above
   1.178 -which will become corrupted if the contexts are not done in
   1.179 -parallel. The solution is to create a copy of this normally global
   1.180 -device state for each context, and copy it back and forth into and out
   1.181 -of the actual device state whenever a context is rendered.
   1.182 -
   1.183 -** Synchronization Macros
   1.184 -#+name: sync-macros
   1.185 -#+begin_src C
   1.186 -////////////////////  Context Creation / Synchronization
   1.187 -
   1.188 -#define _MAKE_SYNC(NAME, INIT_EXPR, GET_EXPR, SET_EXPR)	\
   1.189 -  void NAME (ALuint sourceID1, ALuint sourceID2,	\
   1.190 -	     ALCcontext *ctx1, ALCcontext *ctx2,	\
   1.191 -	     ALenum param){				\
   1.192 -    INIT_EXPR;						\
   1.193 -    ALCcontext *current = alcGetCurrentContext();	\
   1.194 -    alcMakeContextCurrent(ctx1);			\
   1.195 -    GET_EXPR;						\
   1.196 -    alcMakeContextCurrent(ctx2);			\
   1.197 -    SET_EXPR;						\
   1.198 -    alcMakeContextCurrent(current);			\
   1.199 -  }
   1.200 -  
   1.201 -#define MAKE_SYNC(NAME, TYPE, GET, SET)			\
   1.202 -  _MAKE_SYNC(NAME,					\
   1.203 -	     TYPE value,				\
   1.204 -             GET(sourceID1, param, &value),		\
   1.205 -             SET(sourceID2, param, value))
   1.206 -  
   1.207 -#define MAKE_SYNC3(NAME, TYPE, GET, SET)				\
   1.208 -  _MAKE_SYNC(NAME,							\
   1.209 -	     TYPE value1; TYPE value2; TYPE value3;,			\
   1.210 -	     GET(sourceID1, param, &value1, &value2, &value3),		\
   1.211 -	     SET(sourceID2, param,  value1,  value2,  value3))
   1.212 -
   1.213 -MAKE_SYNC( syncSourcei,  ALint,   alGetSourcei,  alSourcei);
   1.214 -MAKE_SYNC( syncSourcef,  ALfloat, alGetSourcef,  alSourcef);
   1.215 -MAKE_SYNC3(syncSource3i, ALint,   alGetSource3i, alSource3i);
   1.216 -MAKE_SYNC3(syncSource3f, ALfloat, alGetSource3f, alSource3f);
   1.217 -  
   1.218 -#+end_src
   1.219 -
   1.220 -Setting the state of an =OpenAL= source is done with the =alSourcei=,
   1.221 -=alSourcef=, =alSource3i=, and =alSource3f= functions.  In order to
   1.222 -completely synchronize two sources, it is necessary to use all of
   1.223 -them. These macros help to condense the otherwise repetitive
   1.224 -synchronization code involving these similar low-level =OpenAL= functions.
   1.225 -
   1.226 -** Source Synchronization
   1.227 -#+name: sync-sources
   1.228 -#+begin_src C
   1.229 -void syncSources(ALsource *masterSource, ALsource *slaveSource, 
   1.230 -		 ALCcontext *masterCtx, ALCcontext *slaveCtx){
   1.231 -  ALuint master = masterSource->source;
   1.232 -  ALuint slave = slaveSource->source;
   1.233 -  ALCcontext *current = alcGetCurrentContext();
   1.234 -
   1.235 -  syncSourcef(master,slave,masterCtx,slaveCtx,AL_PITCH);
   1.236 -  syncSourcef(master,slave,masterCtx,slaveCtx,AL_GAIN);
   1.237 -  syncSourcef(master,slave,masterCtx,slaveCtx,AL_MAX_DISTANCE);
   1.238 -  syncSourcef(master,slave,masterCtx,slaveCtx,AL_ROLLOFF_FACTOR);
   1.239 -  syncSourcef(master,slave,masterCtx,slaveCtx,AL_REFERENCE_DISTANCE);
   1.240 -  syncSourcef(master,slave,masterCtx,slaveCtx,AL_MIN_GAIN);
   1.241 -  syncSourcef(master,slave,masterCtx,slaveCtx,AL_MAX_GAIN);
   1.242 -  syncSourcef(master,slave,masterCtx,slaveCtx,AL_CONE_OUTER_GAIN);
   1.243 -  syncSourcef(master,slave,masterCtx,slaveCtx,AL_CONE_INNER_ANGLE);
   1.244 -  syncSourcef(master,slave,masterCtx,slaveCtx,AL_CONE_OUTER_ANGLE);
   1.245 -  syncSourcef(master,slave,masterCtx,slaveCtx,AL_SEC_OFFSET);
   1.246 -  syncSourcef(master,slave,masterCtx,slaveCtx,AL_SAMPLE_OFFSET);
   1.247 -  syncSourcef(master,slave,masterCtx,slaveCtx,AL_BYTE_OFFSET);
   1.248 -    
   1.249 -  syncSource3f(master,slave,masterCtx,slaveCtx,AL_POSITION);
   1.250 -  syncSource3f(master,slave,masterCtx,slaveCtx,AL_VELOCITY);
   1.251 -  syncSource3f(master,slave,masterCtx,slaveCtx,AL_DIRECTION);
   1.252 -  
   1.253 -  syncSourcei(master,slave,masterCtx,slaveCtx,AL_SOURCE_RELATIVE);
   1.254 -  syncSourcei(master,slave,masterCtx,slaveCtx,AL_LOOPING);
   1.255 -
   1.256 -  alcMakeContextCurrent(masterCtx);
   1.257 -  ALint source_type;
   1.258 -  alGetSourcei(master, AL_SOURCE_TYPE, &source_type);
   1.259 -
   1.260 -  // Only static sources are currently synchronized! 
   1.261 -  if (AL_STATIC == source_type){
   1.262 -    ALint master_buffer;
   1.263 -    ALint slave_buffer;
   1.264 -    alGetSourcei(master, AL_BUFFER, &master_buffer);
   1.265 -    alcMakeContextCurrent(slaveCtx);
   1.266 -    alGetSourcei(slave, AL_BUFFER, &slave_buffer);
   1.267 -    if (master_buffer != slave_buffer){
   1.268 -      alSourcei(slave, AL_BUFFER, master_buffer);
   1.269 -    }
   1.270 -  }
   1.271 -  
   1.272 -  // Synchronize the state of the two sources.
   1.273 -  alcMakeContextCurrent(masterCtx);
   1.274 -  ALint masterState;
   1.275 -  ALint slaveState;
   1.276 -
   1.277 -  alGetSourcei(master, AL_SOURCE_STATE, &masterState);
   1.278 -  alcMakeContextCurrent(slaveCtx);
   1.279 -  alGetSourcei(slave, AL_SOURCE_STATE, &slaveState);
   1.280 -
   1.281 -  if (masterState != slaveState){
   1.282 -    switch (masterState){
   1.283 -    case AL_INITIAL : alSourceRewind(slave); break;
   1.284 -    case AL_PLAYING : alSourcePlay(slave);   break;
   1.285 -    case AL_PAUSED  : alSourcePause(slave);  break;
   1.286 -    case AL_STOPPED : alSourceStop(slave);   break;
   1.287 -    }
   1.288 -  }
   1.289 -  // Restore whatever context was previously active.
   1.290 -  alcMakeContextCurrent(current);
   1.291 -}
   1.292 -#+end_src
   1.293 -This function is long because it has to exhaustively go through all the
   1.294 -possible state that a source can have and make sure that it is the
   1.295 -same between the master and slave sources.  I'd like to take this
   1.296 -moment to salute the [[http://connect.creativelabs.com/openal/Documentation/Forms/AllItems.aspx][=OpenAL= Reference Manual]], which provides a very
   1.297 -good description of =OpenAL='s internals.
   1.298 -
   1.299 -** Context Synchronization
   1.300 -#+name: sync-contexts
   1.301 -#+begin_src C
   1.302 -void syncContexts(ALCcontext *master, ALCcontext *slave){
   1.303 -  /* If there aren't sufficient sources in slave to mirror 
   1.304 -     the sources in master, create them. */
   1.305 -  ALCcontext *current = alcGetCurrentContext();
   1.306 -
   1.307 -  UIntMap *masterSourceMap = &(master->SourceMap);
   1.308 -  UIntMap *slaveSourceMap = &(slave->SourceMap);
   1.309 -  ALuint numMasterSources = masterSourceMap->size;
   1.310 -  ALuint numSlaveSources = slaveSourceMap->size;
   1.311 -
   1.312 -  alcMakeContextCurrent(slave);
   1.313 -  if (numSlaveSources < numMasterSources){
   1.314 -    ALuint numMissingSources = numMasterSources - numSlaveSources;
   1.315 -    ALuint newSources[numMissingSources];
   1.316 -    alGenSources(numMissingSources, newSources);
   1.317 -  }
   1.318 -
   1.319 -  /* Now, slave is guaranteed to have at least as many sources
   1.320 -     as master.  Sync each source from master to the corresponding
   1.321 -     source in slave. */
   1.322 -  int i;
   1.323 -  for(i = 0; i < masterSourceMap->size; i++){
   1.324 -    syncSources((ALsource*)masterSourceMap->array[i].value,
   1.325 -		(ALsource*)slaveSourceMap->array[i].value,
   1.326 -		master, slave);
   1.327 -  }
   1.328 -  alcMakeContextCurrent(current);
   1.329 -}
   1.330 -#+end_src
   1.331 -
   1.332 -Most of the hard work in Context Synchronization is done in
   1.333 -=syncSources()=. The only thing that =syncContexts()= has to worry
   1.334 -about is automatically creating new sources whenever a slave context
   1.335 -does not have the same number of sources as the master context.
   1.336 -
   1.337 -** Context Creation
   1.338 -#+name: context-creation
   1.339 -#+begin_src C
   1.340 -static void addContext(ALCdevice *Device, ALCcontext *context){
   1.341 -  send_data *data = (send_data*)Device->ExtraData;
   1.342 -  // expand array if necessary
   1.343 -  if (data->numContexts >= data->maxContexts){
   1.344 -    ALuint newMaxContexts = data->maxContexts*2 + 1;
   1.345 -    data->contexts = realloc(data->contexts, newMaxContexts*sizeof(context_data));
   1.346 -    data->maxContexts = newMaxContexts;
   1.347 -  }
   1.348 -  // create context_data and add it to the main array
   1.349 -  context_data *ctxData;
   1.350 -  ctxData = (context_data*)calloc(1, sizeof(*ctxData));
   1.351 -  ctxData->renderBuffer = 
   1.352 -    malloc(BytesFromDevFmt(Device->FmtType) * 
   1.353 -	   Device->NumChan * Device->UpdateSize);
   1.354 -  ctxData->ctx = context;
   1.355 -
   1.356 -  data->contexts[data->numContexts] = ctxData;
   1.357 -  data->numContexts++;
   1.358 -}
   1.359 -#+end_src
   1.360 -
   1.361 -Here, the slave context is created, and it's data is stored in the
   1.362 -device-wide =ExtraData= structure.  The =renderBuffer= that is created
   1.363 -here is where the rendered sound samples for this slave context will
   1.364 -eventually go.
   1.365 -
   1.366 -** Context Switching
   1.367 -#+name: context-switching
   1.368 -#+begin_src C
   1.369 -////////////////////  Context Switching 
   1.370 -
   1.371 -/* A device brings along with it two pieces of state
   1.372 - * which have to be swapped in and out with each context.
   1.373 - */
   1.374 -static void swapInContext(ALCdevice *Device, context_data *ctxData){
   1.375 -  memcpy(Device->ClickRemoval, ctxData->ClickRemoval, sizeof(ALfloat)*MAXCHANNELS);
   1.376 -  memcpy(Device->PendingClicks, ctxData->PendingClicks, sizeof(ALfloat)*MAXCHANNELS);
   1.377 -}
   1.378 -
   1.379 -static void saveContext(ALCdevice *Device, context_data *ctxData){
   1.380 -  memcpy(ctxData->ClickRemoval, Device->ClickRemoval, sizeof(ALfloat)*MAXCHANNELS);
   1.381 -  memcpy(ctxData->PendingClicks, Device->PendingClicks, sizeof(ALfloat)*MAXCHANNELS);
   1.382 -}  
   1.383 -
   1.384 -static ALCcontext **currentContext;
   1.385 -static ALuint currentNumContext;
   1.386 -
   1.387 -/* By default, all contexts are rendered at once for each call to aluMixData.
   1.388 - * This function uses the internals of the ALCdevice struct to temporally 
   1.389 - * cause aluMixData to only render the chosen context.
   1.390 - */
   1.391 -static void limitContext(ALCdevice *Device, ALCcontext *ctx){
   1.392 -  currentContext  = Device->Contexts;
   1.393 -  currentNumContext  = Device->NumContexts;
   1.394 -  Device->Contexts = &ctx;
   1.395 -  Device->NumContexts = 1;
   1.396 -}
   1.397 -
   1.398 -static void unLimitContext(ALCdevice *Device){
   1.399 -  Device->Contexts = currentContext;
   1.400 -  Device->NumContexts = currentNumContext;
   1.401 -}
   1.402 -#+end_src
   1.403 -
   1.404 -=OpenAL= normally renders all Contexts in parallel, outputting the
   1.405 -whole result to the buffer.  It does this by iterating over the
   1.406 -Device->Contexts array and rendering each context to the buffer in
   1.407 -turn.  By temporally setting Device->NumContexts to 1 and adjusting
   1.408 -the Device's context list to put the desired context-to-be-rendered
   1.409 -into position 0, we can get trick =OpenAL= into rendering each slave
   1.410 -context separate from all the others.
   1.411 -
   1.412 -** Main Device Loop
   1.413 -#+name: main-loop
   1.414 -#+begin_src C
   1.415 -////////////////////   Main Device Loop
   1.416 -
   1.417 -/* Establish the LWJGL context as the master context, which will
   1.418 - * be synchronized to all the slave contexts
   1.419 - */
   1.420 -static void init(ALCdevice *Device){
   1.421 -  ALCcontext *masterContext = alcGetCurrentContext();
   1.422 -  addContext(Device, masterContext);
   1.423 -}
   1.424 -
   1.425 -
   1.426 -static void renderData(ALCdevice *Device, int samples){
   1.427 -  if(!Device->Connected){return;}
   1.428 -  send_data *data = (send_data*)Device->ExtraData;
   1.429 -  ALCcontext *current = alcGetCurrentContext();
   1.430 -
   1.431 -  ALuint i;
   1.432 -  for (i = 1; i < data->numContexts; i++){
   1.433 -    syncContexts(data->contexts[0]->ctx , data->contexts[i]->ctx);
   1.434 -  }
   1.435 -  
   1.436 -  if ((ALuint) samples > Device->UpdateSize){
   1.437 -    printf("exceeding internal buffer size; dropping samples\n");
   1.438 -    printf("requested %d; available %d\n", samples, Device->UpdateSize);
   1.439 -    samples = (int) Device->UpdateSize;
   1.440 -  }
   1.441 -
   1.442 -  for (i = 0; i < data->numContexts; i++){
   1.443 -    context_data *ctxData = data->contexts[i];
   1.444 -    ALCcontext *ctx = ctxData->ctx;
   1.445 -    alcMakeContextCurrent(ctx);
   1.446 -    limitContext(Device, ctx);
   1.447 -    swapInContext(Device, ctxData);
   1.448 -    aluMixData(Device, ctxData->renderBuffer, samples);
   1.449 -    saveContext(Device, ctxData);
   1.450 -    unLimitContext(Device);
   1.451 -  }
   1.452 -  alcMakeContextCurrent(current);
   1.453 -}
   1.454 -#+end_src
   1.455 -
   1.456 -The main loop synchronizes the master LWJGL context with all the slave
   1.457 -contexts, then walks each context, rendering just that context to it's
   1.458 -audio-sample storage buffer.
   1.459 -
   1.460 -** JNI Methods
   1.461 -
   1.462 -At this point, we have the ability to create multiple listeners by
   1.463 -using the master/slave context trick, and the rendered audio data is
   1.464 -waiting patiently in internal buffers, one for each listener.  We need
   1.465 -a way to transport this information to Java, and also a way to drive
   1.466 -this device from Java.  The following JNI interface code is inspired
   1.467 -by the way LWJGL interfaces with =OpenAL=.
   1.468 -
   1.469 -*** step
   1.470 -#+name: jni-step
   1.471 -#+begin_src C
   1.472 -////////////////////   JNI Methods
   1.473 -
   1.474 -#include "com_aurellem_send_AudioSend.h"
   1.475 -
   1.476 -/*
   1.477 - * Class:     com_aurellem_send_AudioSend
   1.478 - * Method:    nstep
   1.479 - * Signature: (JI)V
   1.480 - */
   1.481 -JNIEXPORT void JNICALL Java_com_aurellem_send_AudioSend_nstep
   1.482 -(JNIEnv *env, jclass clazz, jlong device, jint samples){
   1.483 -  UNUSED(env);UNUSED(clazz);UNUSED(device);
   1.484 -  renderData((ALCdevice*)((intptr_t)device), samples);
   1.485 -}
   1.486 -#+end_src
   1.487 -This device, unlike most of the other devices in =OpenAL=, does not
   1.488 -render sound unless asked. This enables the system to slow down or
   1.489 -speed up depending on the needs of the AIs who are using it to
   1.490 -listen.  If the device tried to render samples in real-time, a
   1.491 -complicated AI whose mind takes 100 seconds of computer time to
   1.492 -simulate 1 second of AI-time would miss almost all of the sound in
   1.493 -its environment.
   1.494 -
   1.495 -
   1.496 -*** getSamples
   1.497 -#+name: jni-get-samples
   1.498 -#+begin_src C
   1.499 -/*
   1.500 - * Class:     com_aurellem_send_AudioSend
   1.501 - * Method:    ngetSamples
   1.502 - * Signature: (JLjava/nio/ByteBuffer;III)V
   1.503 - */
   1.504 -JNIEXPORT void JNICALL Java_com_aurellem_send_AudioSend_ngetSamples
   1.505 -(JNIEnv *env, jclass clazz, jlong device, jobject buffer, jint position, 
   1.506 - jint samples, jint n){
   1.507 -  UNUSED(clazz);  
   1.508 -
   1.509 -  ALvoid *buffer_address = 
   1.510 -    ((ALbyte *)(((char*)(*env)->GetDirectBufferAddress(env, buffer)) + position));
   1.511 -  ALCdevice *recorder = (ALCdevice*) ((intptr_t)device);
   1.512 -  send_data *data = (send_data*)recorder->ExtraData;
   1.513 -  if ((ALuint)n > data->numContexts){return;}
   1.514 -  memcpy(buffer_address, data->contexts[n]->renderBuffer, 
   1.515 -	 BytesFromDevFmt(recorder->FmtType) * recorder->NumChan * samples);
   1.516 -}
   1.517 -#+end_src
   1.518 -
   1.519 -This is the transport layer between C and Java that will eventually
   1.520 -allow us to access rendered sound data from clojure.
   1.521 -
   1.522 -*** Listener Management
   1.523 -
   1.524 -=addListener=, =setNthListenerf=, and =setNthListener3f= are
   1.525 -necessary to change the properties of any listener other than the
   1.526 -master one, since only the listener of the current active context is
   1.527 -affected by the normal =OpenAL= listener calls.
   1.528 -#+name: listener-manage
   1.529 -#+begin_src C
   1.530 -/*
   1.531 - * Class:     com_aurellem_send_AudioSend
   1.532 - * Method:    naddListener
   1.533 - * Signature: (J)V
   1.534 - */
   1.535 -JNIEXPORT void JNICALL Java_com_aurellem_send_AudioSend_naddListener
   1.536 -(JNIEnv *env, jclass clazz, jlong device){
   1.537 -  UNUSED(env); UNUSED(clazz);
   1.538 -  //printf("creating new context via naddListener\n");
   1.539 -  ALCdevice *Device = (ALCdevice*) ((intptr_t)device);
   1.540 -  ALCcontext *new = alcCreateContext(Device, NULL);
   1.541 -  addContext(Device, new);
   1.542 -}
   1.543 -
   1.544 -/*
   1.545 - * Class:     com_aurellem_send_AudioSend
   1.546 - * Method:    nsetNthListener3f
   1.547 - * Signature: (IFFFJI)V
   1.548 - */
   1.549 -JNIEXPORT void JNICALL Java_com_aurellem_send_AudioSend_nsetNthListener3f
   1.550 -  (JNIEnv *env, jclass clazz, jint param, 
   1.551 -   jfloat v1, jfloat v2, jfloat v3, jlong device, jint contextNum){
   1.552 -  UNUSED(env);UNUSED(clazz);
   1.553 -
   1.554 -  ALCdevice *Device = (ALCdevice*) ((intptr_t)device);
   1.555 -  send_data *data = (send_data*)Device->ExtraData;
   1.556 -  
   1.557 -  ALCcontext *current = alcGetCurrentContext();
   1.558 -  if ((ALuint)contextNum > data->numContexts){return;}
   1.559 -  alcMakeContextCurrent(data->contexts[contextNum]->ctx);
   1.560 -  alListener3f(param, v1, v2, v3);
   1.561 -  alcMakeContextCurrent(current);
   1.562 -}
   1.563 -
   1.564 -/*
   1.565 - * Class:     com_aurellem_send_AudioSend
   1.566 - * Method:    nsetNthListenerf
   1.567 - * Signature: (IFJI)V
   1.568 - */
   1.569 -JNIEXPORT void JNICALL Java_com_aurellem_send_AudioSend_nsetNthListenerf
   1.570 -(JNIEnv *env, jclass clazz, jint param, jfloat v1, jlong device, 
   1.571 - jint contextNum){
   1.572 -
   1.573 -  UNUSED(env);UNUSED(clazz);
   1.574 -  
   1.575 -  ALCdevice *Device = (ALCdevice*) ((intptr_t)device);
   1.576 -  send_data *data = (send_data*)Device->ExtraData;
   1.577 -  
   1.578 -  ALCcontext *current = alcGetCurrentContext();
   1.579 -  if ((ALuint)contextNum > data->numContexts){return;}
   1.580 -  alcMakeContextCurrent(data->contexts[contextNum]->ctx);
   1.581 -  alListenerf(param, v1);
   1.582 -  alcMakeContextCurrent(current);
   1.583 -}
   1.584 -#+end_src
   1.585 -
   1.586 -*** Initialization
   1.587 -=initDevice= is called from the Java side after LWJGL has created its
   1.588 -context, and before any calls to =addListener=. It establishes the
   1.589 -LWJGL context as the master context.
   1.590 -
   1.591 -=getAudioFormat= is a convenience function that uses JNI to build up a
   1.592 -=javax.sound.sampled.AudioFormat= object from data in the Device. This
   1.593 -way, there is no ambiguity about what the bits created by =step= and
   1.594 -returned by =getSamples= mean.
   1.595 -#+name: jni-init
   1.596 -#+begin_src C
   1.597 -/*
   1.598 - * Class:     com_aurellem_send_AudioSend
   1.599 - * Method:    ninitDevice
   1.600 - * Signature: (J)V
   1.601 - */                     
   1.602 -JNIEXPORT void JNICALL Java_com_aurellem_send_AudioSend_ninitDevice
   1.603 -(JNIEnv *env, jclass clazz, jlong device){
   1.604 -  UNUSED(env);UNUSED(clazz);
   1.605 -  ALCdevice *Device = (ALCdevice*) ((intptr_t)device);
   1.606 -  init(Device);
   1.607 -}
   1.608 -
   1.609 -/*
   1.610 - * Class:     com_aurellem_send_AudioSend
   1.611 - * Method:    ngetAudioFormat
   1.612 - * Signature: (J)Ljavax/sound/sampled/AudioFormat;
   1.613 - */
   1.614 -JNIEXPORT jobject JNICALL Java_com_aurellem_send_AudioSend_ngetAudioFormat
   1.615 -(JNIEnv *env, jclass clazz, jlong device){
   1.616 -  UNUSED(clazz);
   1.617 -  jclass AudioFormatClass = 
   1.618 -    (*env)->FindClass(env, "javax/sound/sampled/AudioFormat");
   1.619 -  jmethodID AudioFormatConstructor = 
   1.620 -    (*env)->GetMethodID(env, AudioFormatClass, "<init>", "(FIIZZ)V");
   1.621 -  
   1.622 -  ALCdevice *Device = (ALCdevice*) ((intptr_t)device);
   1.623 -  int isSigned;
   1.624 -  switch (Device->FmtType)
   1.625 -    {
   1.626 -    case DevFmtUByte: 
   1.627 -    case DevFmtUShort: isSigned = 0; break;  
   1.628 -    default : isSigned = 1;   
   1.629 -    }
   1.630 -  float frequency = Device->Frequency;
   1.631 -  int bitsPerFrame = (8 * BytesFromDevFmt(Device->FmtType));
   1.632 -  int channels = Device->NumChan;
   1.633 -  jobject format = (*env)->
   1.634 -    NewObject(
   1.635 -	      env,AudioFormatClass,AudioFormatConstructor,
   1.636 -	      frequency,
   1.637 -	      bitsPerFrame,
   1.638 -	      channels,
   1.639 -	      isSigned,
   1.640 -	      0);
   1.641 -  return format;
   1.642 -}
   1.643 -#+end_src
   1.644 -
   1.645 -** Boring Device management stuff
   1.646 -This code is more-or-less copied verbatim from the other =OpenAL=
   1.647 -backends. It's the basis for =OpenAL='s primitive object system.
   1.648 -#+name: device-init
   1.649 -#+begin_src C
   1.650 -////////////////////   Device Initialization / Management
   1.651 -
   1.652 -static const ALCchar sendDevice[] = "Multiple Audio Send";
   1.653 -
   1.654 -static ALCboolean send_open_playback(ALCdevice *device, 
   1.655 - const ALCchar *deviceName)
   1.656 -{
   1.657 -  send_data *data;
   1.658 -  // stop any buffering for stdout, so that I can 
   1.659 -  // see the printf statements in my terminal immediately
   1.660 -  setbuf(stdout, NULL);
   1.661 -
   1.662 -  if(!deviceName)
   1.663 -    deviceName = sendDevice;
   1.664 -  else if(strcmp(deviceName, sendDevice) != 0)
   1.665 -    return ALC_FALSE;
   1.666 -  data = (send_data*)calloc(1, sizeof(*data));
   1.667 -  device->szDeviceName = strdup(deviceName);
   1.668 -  device->ExtraData = data;
   1.669 -  return ALC_TRUE;
   1.670 -}
   1.671 -
   1.672 -static void send_close_playback(ALCdevice *device)
   1.673 -{
   1.674 -  send_data *data = (send_data*)device->ExtraData;
   1.675 -  alcMakeContextCurrent(NULL);
   1.676 -  ALuint i;
   1.677 -  // Destroy all slave contexts. LWJGL will take care of 
   1.678 -  // its own context.
   1.679 -  for (i = 1; i < data->numContexts; i++){
   1.680 -    context_data *ctxData = data->contexts[i];
   1.681 -    alcDestroyContext(ctxData->ctx);
   1.682 -    free(ctxData->renderBuffer);
   1.683 -    free(ctxData);
   1.684 -  }
   1.685 -  free(data);
   1.686 -  device->ExtraData = NULL;
   1.687 -}
   1.688 -
   1.689 -static ALCboolean send_reset_playback(ALCdevice *device)
   1.690 -{
   1.691 -  SetDefaultWFXChannelOrder(device);
   1.692 -  return ALC_TRUE;
   1.693 -}
   1.694 -
   1.695 -static void send_stop_playback(ALCdevice *Device){
   1.696 -  UNUSED(Device);
   1.697 -}
   1.698 -
   1.699 -static const BackendFuncs send_funcs = {
   1.700 -  send_open_playback,
   1.701 -  send_close_playback,
   1.702 -  send_reset_playback,
   1.703 -  send_stop_playback,
   1.704 -  NULL,
   1.705 -  NULL,  /* These would be filled with functions to    */
   1.706 -  NULL,  /* handle capturing audio if we we into that  */
   1.707 -  NULL,  /* sort of thing...                           */
   1.708 -  NULL,
   1.709 -  NULL
   1.710 -};
   1.711 -
   1.712 -ALCboolean alc_send_init(BackendFuncs *func_list){
   1.713 -  *func_list = send_funcs;
   1.714 -  return ALC_TRUE;
   1.715 -}
   1.716 -
   1.717 -void alc_send_deinit(void){}
   1.718 -
   1.719 -void alc_send_probe(enum DevProbe type)
   1.720 -{
   1.721 -  switch(type)
   1.722 -    {
   1.723 -    case DEVICE_PROBE:
   1.724 -      AppendDeviceList(sendDevice);
   1.725 -      break;
   1.726 -    case ALL_DEVICE_PROBE:
   1.727 -      AppendAllDeviceList(sendDevice);
   1.728 -      break;
   1.729 -    case CAPTURE_DEVICE_PROBE:
   1.730 -      break;
   1.731 -    }
   1.732 -}
   1.733 -#+end_src
   1.734 -
   1.735 -* The Java interface, =AudioSend=
   1.736 -
   1.737 -The Java interface to the Send Device follows naturally from the JNI
   1.738 -definitions. It is included here for completeness. The only thing here
   1.739 -of note is the =deviceID=. This is available from LWJGL, but to only
   1.740 -way to get it is reflection. Unfortunately, there is no other way to
   1.741 -control the Send device than to obtain a pointer to it.
   1.742 -
   1.743 -#+include: "../java/src/com/aurellem/send/AudioSend.java" src java :exports code
   1.744 -
   1.745 -* Finally, Ears in clojure! 
   1.746 -
   1.747 -Now that the infrastructure is complete (modulo a few patches to
   1.748 -jMonkeyEngine3 to support accessing this modified version of =OpenAL=
   1.749 -that are not worth discussing), the clojure ear abstraction is rather
   1.750 -simple.  Just as there were =SceneProcessors= for vision, there are
   1.751 -now =SoundProcessors= for hearing.
   1.752 -
   1.753 -#+include "../../jmeCapture/src/com/aurellem/capture/audio/SoundProcessor.java" src java 
   1.754 -
   1.755 -#+name: ears
   1.756 -#+begin_src clojure
   1.757 -(ns cortex.hearing
   1.758 -  "Simulate the sense of hearing in jMonkeyEngine3. Enables multiple
   1.759 -  listeners at different positions in the same world. Passes vectors
   1.760 -  of floats in the range [-1.0 -- 1.0] in PCM format to any arbitrary
   1.761 -  function."
   1.762 -  {:author "Robert McIntyre"}
   1.763 -  (:use (cortex world util sense))
   1.764 -  (:import java.nio.ByteBuffer)
   1.765 -  (:import org.tritonus.share.sampled.FloatSampleTools)
   1.766 -  (:import com.aurellem.capture.audio.SoundProcessor)
   1.767 -  (:import javax.sound.sampled.AudioFormat))
   1.768 -
   1.769 -(cortex.import/mega-import-jme3)  
   1.770 -
   1.771 -(defn sound-processor
   1.772 -  "Deals with converting ByteBuffers into Vectors of floats so that
   1.773 -  the continuation functions can be defined in terms of immutable
   1.774 -  stuff."
   1.775 -  [continuation]
   1.776 -  (proxy [SoundProcessor] []
   1.777 -    (cleanup [])
   1.778 -    (process
   1.779 -      [#^ByteBuffer audioSamples numSamples #^AudioFormat audioFormat]
   1.780 -      (let [bytes  (byte-array numSamples)
   1.781 -            num-floats (/ numSamples  (.getFrameSize audioFormat))
   1.782 -            floats (float-array num-floats)]
   1.783 -        (.get audioSamples bytes 0 numSamples)
   1.784 -        (FloatSampleTools/byte2floatInterleaved
   1.785 -         bytes 0 floats 0 num-floats audioFormat)
   1.786 -        (continuation
   1.787 -         (vec floats))))))
   1.788 -
   1.789 -
   1.790 -
   1.791 -
   1.792 -;; Ears work the same way as vision.
   1.793 -
   1.794 -;; (hearing creature) will return [init-functions
   1.795 -;; sensor-functions]. The init functions each take the world and
   1.796 -;; register a SoundProcessor that does foureier transforms on the
   1.797 -;; incommong sound data, making it available to each sensor function.
   1.798 -
   1.799 -(defn creature-ears
   1.800 -  "Return the children of the creature's \"ears\" node."
   1.801 -  ;;dylan
   1.802 -  ;;"The ear nodes which are children of the \"ears\" node in the
   1.803 -  ;;creature."
   1.804 -  [#^Node creature]
   1.805 -  (if-let [ear-node (.getChild creature "ears")]
   1.806 -    (seq (.getChildren ear-node))
   1.807 -    (do (println-repl "could not find ears node") [])))
   1.808 -
   1.809 -
   1.810 -;;dylan (defn follow-sense, adjoin-sense, attach-stimuli,
   1.811 -;;anchor-qualia, augment-organ, with-organ
   1.812 -
   1.813 -
   1.814 -(defn update-listener-velocity
   1.815 -  "Update the listener's velocity every update loop."
   1.816 -  [#^Spatial obj #^Listener lis]
   1.817 -  (let [old-position (atom (.getLocation lis))]
   1.818 -    (.addControl
   1.819 -     obj
   1.820 -     (proxy [AbstractControl] []
   1.821 -       (controlUpdate [tpf]
   1.822 -         (let [new-position (.getLocation lis)]
   1.823 -           (.setVelocity
   1.824 -            lis 
   1.825 -            (.mult (.subtract new-position @old-position)
   1.826 -                   (float (/ tpf))))
   1.827 -           (reset! old-position new-position)))
   1.828 -       (controlRender [_ _])))))
   1.829 -
   1.830 -(import com.aurellem.capture.audio.AudioSendRenderer)
   1.831 -
   1.832 -(defn attach-ear
   1.833 -  [#^Application world #^Node creature #^Spatial ear continuation]
   1.834 -  (let [target (closest-node creature ear)
   1.835 -        lis (Listener.)
   1.836 -        audio-renderer (.getAudioRenderer world)
   1.837 -        sp (sound-processor continuation)]
   1.838 -    (.setLocation lis (.getWorldTranslation ear))
   1.839 -    (.setRotation lis (.getWorldRotation ear))
   1.840 -    (bind-sense target lis)
   1.841 -    (update-listener-velocity target lis)
   1.842 -    (.addListener audio-renderer lis)
   1.843 -    (.registerSoundProcessor audio-renderer lis sp)))
   1.844 -
   1.845 -(defn enable-hearing
   1.846 -  [#^Node creature #^Spatial ear]
   1.847 -  (let [hearing-data (atom [])]
   1.848 -    [(fn [world]
   1.849 -       (attach-ear world creature ear
   1.850 -                   (fn [data]
   1.851 -                     (reset! hearing-data (vec data)))))
   1.852 -     [(fn []
   1.853 -        (let [data @hearing-data
   1.854 -              topology              
   1.855 -              (vec (map #(vector % 0) (range 0 (count data))))
   1.856 -              scaled-data
   1.857 -              (vec
   1.858 -               (map
   1.859 -                #(rem (int (* 255 (/ (+ 1 %) 2)))  256)
   1.860 -                   data))]
   1.861 -          [topology scaled-data]))
   1.862 -        ]]))
   1.863 -
   1.864 -(defn hearing
   1.865 -  [#^Node creature]
   1.866 -  (reduce
   1.867 -   (fn [[init-a senses-a]
   1.868 -        [init-b senses-b]]
   1.869 -     [(conj init-a init-b)
   1.870 -      (into senses-a senses-b)])
   1.871 -   [[][]]      
   1.872 -   (for [ear (creature-ears creature)]
   1.873 -     (enable-hearing creature ear))))
   1.874 -
   1.875 -
   1.876 -#+end_src
   1.877 -
   1.878 -* Example
   1.879 -
   1.880 -#+name: test-hearing
   1.881 -#+begin_src clojure :results silent
   1.882 -(ns cortex.test.hearing
   1.883 -  (:use (cortex world util hearing))
   1.884 -  (:import (com.jme3.audio AudioNode Listener))
   1.885 -  (:import com.jme3.scene.Node
   1.886 -	   com.jme3.system.AppSettings))
   1.887 -
   1.888 -(defn setup-fn [world]
   1.889 -  (let [listener (Listener.)]
   1.890 -    (add-ear world listener #(println-repl (nth % 0)))))
   1.891 -  
   1.892 -(defn play-sound [node world value]
   1.893 -  (if (not value)
   1.894 -    (do
   1.895 -      (.playSource (.getAudioRenderer world) node))))
   1.896 -
   1.897 -(defn test-basic-hearing []
   1.898 -   (let [node1 (AudioNode. (asset-manager) "Sounds/pure.wav" false false)]
   1.899 -     (world
   1.900 -      (Node.)
   1.901 -      {"key-space" (partial play-sound node1)}
   1.902 -      setup-fn
   1.903 -      no-op)))
   1.904 -
   1.905 -(defn test-advanced-hearing
   1.906 -  "Testing hearing:
   1.907 -   You should see a blue sphere flying around several
   1.908 -   cubes.  As the sphere approaches each cube, it turns
   1.909 -   green."
   1.910 -  []
   1.911 -  (doto (com.aurellem.capture.examples.Advanced.)
   1.912 -    (.setSettings
   1.913 -     (doto (AppSettings. true)
   1.914 -       (.setAudioRenderer "Send")))
   1.915 -    (.setShowSettings false)
   1.916 -    (.setPauseOnLostFocus false)))
   1.917 -
   1.918 -#+end_src
   1.919 -
   1.920 -This extremely basic program prints out the first sample it encounters
   1.921 -at every time stamp. You can see the rendered sound being printed at
   1.922 -the REPL.
   1.923 -
   1.924 - - As a bonus, this method of capturing audio for AI can also be used
   1.925 -   to capture perfect audio from a jMonkeyEngine application, for use
   1.926 -   in demos and the like.
   1.927 -
   1.928 -
   1.929 -* COMMENT Code Generation
   1.930 -
   1.931 -#+begin_src clojure :tangle ../../cortex/src/cortex/hearing.clj
   1.932 -<<ears>>
   1.933 -#+end_src
   1.934 -
   1.935 -#+begin_src clojure :tangle ../../cortex/src/cortex/test/hearing.clj
   1.936 -<<test-hearing>>
   1.937 -#+end_src
   1.938 -
   1.939 -#+begin_src C :tangle ../Alc/backends/send.c
   1.940 -<<send-header>>
   1.941 -<<send-state>>
   1.942 -<<sync-macros>>
   1.943 -<<sync-sources>>
   1.944 -<<sync-contexts>>
   1.945 -<<context-creation>>
   1.946 -<<context-switching>>
   1.947 -<<main-loop>>
   1.948 -<<jni-step>>
   1.949 -<<jni-get-samples>>
   1.950 -<<listener-manage>>
   1.951 -<<jni-init>>
   1.952 -<<device-init>>
   1.953 -#+end_src
   1.954 -
   1.955 -

     2.1 --- a/org/send.org	Fri Feb 03 06:40:59 2012 -0700
     2.2 +++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
     2.3 @@ -1,11 +0,0 @@
     2.4 -#+title: send.c
     2.5 -#+author: Robert McIntyre
     2.6 -#+email: rlm@mit.edu
     2.7 -#+description: some code I wrote to extend open-al
     2.8 -#+SETUPFILE: ../../aurellem/org/setup.org
     2.9 -#+INCLUDE: ../../aurellem/org/level-0.org
    2.10 -
    2.11 -
    2.12 -#+include /home/r/proj/audio-send/Alc/backends/send.c src C
    2.13 -
    2.14 -