adding audiovoice and polysynth class for polyphonic synths

Gruntfile.js

@@ -125,7 +125,9 @@ module.exports = function(grunt) {
             'signal': 'src/signal',
             'metro': 'src/metro',
             'peakdetect': 'src/peakDetect',
-            'gain': 'src/gain'
+            'gain': 'src/gain',
+            'audiovoice': 'src/audiovoice',
+            'polysynth': 'src/polysynth'
           },
           useStrict: true,
           wrap: {

src/app.js

@@ -24,6 +24,8 @@ define(function (require) {
   require('soundRecorder');
   require('peakdetect');
   require('gain');
+  require('audiovoice');
+  require('polysynth');
 
   return p5SOUND;
 

src/audiovoice.js

@@ -0,0 +1,128 @@
+define(function (require) {
+  'use strict';
+
+  var p5sound = require('master');
+  require('sndcore');
+
+     /**
+    *  An AudioVoice is used as a single voice for sound synthesis.
+    *
+    *  @class p5.AudioVoice
+    *  @constructor
+    *
+    *  This is a class to be used in conjonction with the PolySynth
+    *  class. Custom synthetisers should be built inheriting from
+    *  this class.
+    **/
+
+p5.AudioVoice = function (){
+
+  this.osctype = 'sine';
+  this.volume= 0.33;
+  this.note = 60;
+
+  this.attack = 0.25;
+  this.decay=0.25;
+  this.sustain=0.95;
+  this.release=0.25;
+  this.env = new p5.Env(this.attack,this.volume, this.decay,this.volume,  this.sustain, this.volume,this.release);
+
+  this.filter = new p5.LowPass();
+  this.filter.set(22050, 5);
+
+  this.env.connect(this.filter);
+
+}
+
+
+/**
+   *  Play the envelopp
+   *  
+   *  @method  voicePlay
+   */  
+
+p5.AudioVoice.prototype.voicePlay = function (){
+  this.env.play(this.filter);
+}
+
+/**
+   *  Trigger the attack
+   *  
+   *  @method  attackPlay
+   */  
+p5.AudioVoice.prototype.attackPlay = function (){
+  this.env.triggerAttack(this.oscillator);
+}
+
+/**
+   *  Trigger the release
+   *  
+   *  @method  releasePlay
+   */  
+
+p5.AudioVoice.prototype.releasePlay = function (){
+  this.env.triggerRelease(this.oscillator);
+}
+
+/**
+   *  Set the note to be played.
+   *  This method can be overriden when creating custom synth
+   *  
+   *  @method  setNote
+   *  @param  {Number} Midi note to be played (from 0 to 127).
+   * 
+   */  
+
+p5.AudioVoice.prototype.setNote = function(note){
+  this.oscillator.freq(midiToFreq(note));
+}
+
+/**
+   *  Set cutoms parameters to a specific synth implementation.
+   *  This method does nothing by default unless you implement
+   *  something for it.
+   *  For instance if you want to build a complex synthetiser
+   *  with one or more filters, effects etc. this is where you
+   *  will want to set them.
+   *  
+   *  @method  setParams
+   *  @param   
+   * 
+   */  
+
+p5.AudioVoice.prototype.setParams = function(params){
+
+}
+
+/**
+   *  Set values like a traditional
+   *  <a href="https://en.wikipedia.org/wiki/Synthesizer#/media/File:ADSR_parameter.svg">
+   *  ADSR envelope
+   *  </a>.
+   *  
+   *  @method  setADSR
+   *  @param {Number} attackTime    Time (in seconds before envelope
+   *                                reaches Attack Level
+   *  @param {Number} [decayTime]    Time (in seconds) before envelope
+   *                                reaches Decay/Sustain Level
+   *  @param {Number} [susRatio]    Ratio between attackLevel and releaseLevel, on a scale from 0 to 1,
+   *                                where 1.0 = attackLevel, 0.0 = releaseLevel.
+   *                                The susRatio determines the decayLevel and the level at which the
+   *                                sustain portion of the envelope will sustain.
+   *                                For example, if attackLevel is 0.4, releaseLevel is 0,
+   *                                and susAmt is 0.5, the decayLevel would be 0.2. If attackLevel is
+   *                                increased to 1.0 (using <code>setRange</code>),
+   *                                then decayLevel would increase proportionally, to become 0.5.
+   *  @param {Number} [releaseTime]   Time in seconds from now (defaults to 0)
+   **/
+
+p5.AudioVoice.prototype.setADSR = function (a,d,s,r){
+  this.attack = a;
+  this.decay=d;
+  this.sustain=s;
+  this.release=r;
+  this.env = new p5.Env(this.attack, this.decay,  this.sustain, this.release); 
+  this.env.play(this.filter);
+}
+
+});

src/polysynth.js

@@ -0,0 +1,101 @@
+define(function (require) {
+  'use strict';
+
+  var p5sound = require('master');
+  require('sndcore');
+  require('audiovoice');
+
+       /**
+    *  An AudioVoice is used as a single voice for sound synthesis.
+    *  The PolySynth class holds an array of AudioVoice, and deals
+    *  with voices allocations, with setting notes to be played, and
+    *  parameters to be set. 
+    *
+    *  @class p5.PolySynth
+    *  @constructor
+    *  @param {Number} [num]    Number of voices used by the polyphonic
+    *                           synthetiser.
+    *                              
+    *  @param {Number} [synthVoice]   A monophonic synth voice inheriting
+    *                                 the AudioVoice class.
+    **/
+
+p5.PolySynth = function(num,synthVoice){
+  this.voices = [];
+  this.num_voices = num;
+  this.poly_counter=0;
+
+  for (var i = 0 ; i < this.num_voices ; i++){
+       this.voices.push(new synthVoice());
+  }
+}
+
+/**
+   *  Play a note.
+   *  
+   *  @method  play
+   */  
+
+p5.PolySynth.prototype.play = function (){
+    this.voices[this.poly_counter].voicePlay();
+    this.poly_counter += 1;
+    this.poly_counter = this.poly_counter % this.num_voices;
+}
+
+
+/**
+   *  Set values like a traditional
+   *  <a href="https://en.wikipedia.org/wiki/Synthesizer#/media/File:ADSR_parameter.svg">
+   *  ADSR envelope
+   *  </a>.
+   *  
+   *  @method  setADSR
+   *  @param {Number} attackTime    Time (in seconds before envelope
+   *                                reaches Attack Level
+   *  @param {Number} [decayTime]    Time (in seconds) before envelope
+   *                                reaches Decay/Sustain Level
+   *  @param {Number} [susRatio]    Ratio between attackLevel and releaseLevel, on a scale from 0 to 1,
+   *                                where 1.0 = attackLevel, 0.0 = releaseLevel.
+   *                                The susRatio determines the decayLevel and the level at which the
+   *                                sustain portion of the envelope will sustain.
+   *                                For example, if attackLevel is 0.4, releaseLevel is 0,
+   *                                and susAmt is 0.5, the decayLevel would be 0.2. If attackLevel is
+   *                                increased to 1.0 (using <code>setRange</code>),
+   *                                then decayLevel would increase proportionally, to become 0.5.
+   *  @param {Number} [releaseTime]   Time in seconds from now (defaults to 0)
+   **/
+
+p5.PolySynth.prototype.setADSR = function (a,d,s,r){
+  this.voices[this.poly_counter].setADSR(a,d,s,r);
+}
+
+/**
+   *  Set the note to be played.
+   *  This method can be overriden when creating custom synth
+   *  
+   *  @method  setNote
+   *  @param  {Number} Midi note to be played (from 0 to 127).
+   * 
+   */  
+
+p5.PolySynth.prototype.setNote = function (note){
+  this.voices[this.poly_counter].setNote(note);
+}
+
+
+/**
+   *  Set cutoms parameters to a specific synth implementation 
+   *  with the help of JavaScript Object Notation (JSON).
+   *  
+   *  @method  setParams
+   *  @param   JSON object  
+   * 
+   *  For instance to set the detune parameter of a synth, call :
+   *  setParams({detune: 15 });
+   *
+   */  
+p5.PolySynth.prototype.setParams = function (params){
+  this.voices[this.poly_counter].setParams(params);
+}
+
+});