mirror of
https://github.com/Tonejs/Tone.js
synced 2024-11-16 16:48:00 +00:00
368 lines
9.5 KiB
JavaScript
368 lines
9.5 KiB
JavaScript
define(["Tone/core/Tone", "Tone/signal/Signal", "Tone/source/Source", "Tone/core/Transport"], function(Tone){
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"use strict";
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/**
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* @class Tone.Oscillator supports a number of features including
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* phase rotation, multiple oscillator types (see Tone.Oscillator.type),
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* and Transport syncing (see Tone.Oscillator.syncFrequency).
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*
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* @constructor
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* @extends {Tone.Source}
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* @param {Frequency} [frequency] Starting frequency
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* @param {string} [type] The oscillator type. Read more about type below.
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* @example
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* //make and start a 440hz sine tone
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* var osc = new Tone.Oscillator(440, "sine").toMaster().start();
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*/
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Tone.Oscillator = function(){
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var options = Tone.defaults(arguments, ["frequency", "type"], Tone.Oscillator);
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Tone.Source.call(this, options);
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/**
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* the main oscillator
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* @type {OscillatorNode}
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* @private
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*/
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this._oscillator = null;
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/**
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* The frequency control.
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* @type {Frequency}
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* @signal
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*/
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this.frequency = new Tone.Signal(options.frequency, Tone.Type.Frequency);
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/**
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* The detune control signal.
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* @type {Cents}
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* @signal
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*/
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this.detune = new Tone.Signal(options.detune, Tone.Type.Cents);
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/**
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* the periodic wave
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* @type {PeriodicWave}
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* @private
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*/
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this._wave = null;
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/**
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* The partials of the oscillator
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* @type {Array}
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* @private
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*/
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this._partials = Tone.defaultArg(options.partials, [1]);
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/**
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* the phase of the oscillator
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* between 0 - 360
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* @type {number}
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* @private
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*/
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this._phase = options.phase;
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/**
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* the type of the oscillator
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* @type {string}
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* @private
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*/
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this._type = null;
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//setup
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this.type = options.type;
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this.phase = this._phase;
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this._readOnly(["frequency", "detune"]);
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};
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Tone.extend(Tone.Oscillator, Tone.Source);
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/**
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* the default parameters
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* @type {Object}
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*/
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Tone.Oscillator.defaults = {
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"type" : "sine",
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"frequency" : 440,
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"detune" : 0,
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"phase" : 0,
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"partials" : []
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};
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/**
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* The Oscillator types
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* @enum {String}
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*/
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Tone.Oscillator.Type = {
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Sine : "sine",
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Triangle : "triangle",
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Sawtooth : "sawtooth",
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Square : "square",
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Custom : "custom"
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};
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/**
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* start the oscillator
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* @param {Time} [time=now]
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* @private
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*/
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Tone.Oscillator.prototype._start = function(time){
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//new oscillator with previous values
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this._oscillator = this.context.createOscillator();
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this._oscillator.setPeriodicWave(this._wave);
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//connect the control signal to the oscillator frequency & detune
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this._oscillator.connect(this.output);
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this.frequency.connect(this._oscillator.frequency);
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this.detune.connect(this._oscillator.detune);
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//start the oscillator
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time = this.toSeconds(time);
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Tone.isPast(time);
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this._oscillator.start(time);
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};
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/**
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* stop the oscillator
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* @private
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* @param {Time} [time=now] (optional) timing parameter
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* @returns {Tone.Oscillator} this
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*/
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Tone.Oscillator.prototype._stop = function(time){
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if (this._oscillator){
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time = this.toSeconds(time);
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Tone.isPast(time);
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this._oscillator.stop(time);
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this._oscillator = null;
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}
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return this;
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};
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/**
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* Sync the signal to the Transport's bpm. Any changes to the transports bpm,
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* will also affect the oscillators frequency.
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* @returns {Tone.Oscillator} this
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* @example
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* Tone.Transport.bpm.value = 120;
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* osc.frequency.value = 440;
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* //the ration between the bpm and the frequency will be maintained
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* osc.syncFrequency();
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* Tone.Transport.bpm.value = 240;
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* // the frequency of the oscillator is doubled to 880
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*/
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Tone.Oscillator.prototype.syncFrequency = function(){
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Tone.Transport.syncSignal(this.frequency);
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return this;
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};
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/**
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* Unsync the oscillator's frequency from the Transport.
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* See Tone.Oscillator.syncFrequency
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* @returns {Tone.Oscillator} this
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*/
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Tone.Oscillator.prototype.unsyncFrequency = function(){
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Tone.Transport.unsyncSignal(this.frequency);
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return this;
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};
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/**
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* The type of the oscillator: either sine, square, triangle, or sawtooth. Also capable of
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* setting the first x number of partials of the oscillator. For example: "sine4" would
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* set be the first 4 partials of the sine wave and "triangle8" would set the first
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* 8 partials of the triangle wave.
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* <br><br>
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* Uses PeriodicWave internally even for native types so that it can set the phase.
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* PeriodicWave equations are from the
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* [Webkit Web Audio implementation](https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit/Source/modules/webaudio/PeriodicWave.cpp&sq=package:chromium).
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*
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* @memberOf Tone.Oscillator#
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* @type {string}
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* @name type
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* @example
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* //set it to a square wave
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* osc.type = "square";
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* @example
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* //set the first 6 partials of a sawtooth wave
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* osc.type = "sawtooth6";
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*/
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Object.defineProperty(Tone.Oscillator.prototype, "type", {
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get : function(){
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return this._type;
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},
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set : function(type){
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var coefs = this._getRealImaginary(type, this._phase);
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var periodicWave = this.context.createPeriodicWave(coefs[0], coefs[1]);
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this._wave = periodicWave;
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if (this._oscillator !== null){
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this._oscillator.setPeriodicWave(this._wave);
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}
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this._type = type;
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}
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});
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/**
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* Returns the real and imaginary components based
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* on the oscillator type.
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* @returns {Array} [real, imaginary]
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* @private
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*/
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Tone.Oscillator.prototype._getRealImaginary = function(type, phase){
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var fftSize = 4096;
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var periodicWaveSize = fftSize / 2;
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var real = new Float32Array(periodicWaveSize);
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var imag = new Float32Array(periodicWaveSize);
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var partialCount = 1;
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if (type === Tone.Oscillator.Type.Custom){
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partialCount = this._partials.length + 1;
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periodicWaveSize = partialCount;
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} else {
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var partial = /^(sine|triangle|square|sawtooth)(\d+)$/.exec(type);
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if (partial){
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partialCount = parseInt(partial[2]) + 1;
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type = partial[1];
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partialCount = Math.max(partialCount, 2);
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periodicWaveSize = partialCount;
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}
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}
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for (var n = 1; n < periodicWaveSize; ++n) {
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var piFactor = 2 / (n * Math.PI);
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var b;
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switch (type) {
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case Tone.Oscillator.Type.Sine:
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b = (n <= partialCount) ? 1 : 0;
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break;
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case Tone.Oscillator.Type.Square:
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b = (n & 1) ? 2 * piFactor : 0;
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break;
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case Tone.Oscillator.Type.Sawtooth:
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b = piFactor * ((n & 1) ? 1 : -1);
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break;
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case Tone.Oscillator.Type.Triangle:
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if (n & 1) {
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b = 2 * (piFactor * piFactor) * ((((n - 1) >> 1) & 1) ? -1 : 1);
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} else {
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b = 0;
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}
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break;
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case Tone.Oscillator.Type.Custom:
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b = this._partials[n - 1];
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break;
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default:
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throw new TypeError("Tone.Oscillator: invalid type: "+type);
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}
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if (b !== 0){
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real[n] = -b * Math.sin(phase * n);
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imag[n] = b * Math.cos(phase * n);
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} else {
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real[n] = 0;
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imag[n] = 0;
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}
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}
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return [real, imag];
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};
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/**
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* Compute the inverse FFT for a given phase.
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* @param {Float32Array} real
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* @param {Float32Array} imag
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* @param {NormalRange} phase
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* @return {AudioRange}
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* @private
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*/
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Tone.Oscillator.prototype._inverseFFT = function(real, imag, phase){
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var sum = 0;
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var len = real.length;
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for (var i = 0; i < len; i++){
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sum += real[i] * Math.cos(i * phase) + imag[i] * Math.sin(i * phase);
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}
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return sum;
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};
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/**
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* Returns the initial value of the oscillator.
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* @return {AudioRange}
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* @private
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*/
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Tone.Oscillator.prototype._getInitialValue = function(){
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var coefs = this._getRealImaginary(this._type, 0);
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var real = coefs[0];
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var imag = coefs[1];
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var maxValue = 0;
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var twoPi = Math.PI * 2;
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//check for peaks in 8 places
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for (var i = 0; i < 8; i++){
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maxValue = Math.max(this._inverseFFT(real, imag, (i / 8) * twoPi), maxValue);
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}
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return -this._inverseFFT(real, imag, this._phase) / maxValue;
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};
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/**
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* The partials of the waveform. A partial represents
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* the amplitude at a harmonic. The first harmonic is the
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* fundamental frequency, the second is the octave and so on
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* following the harmonic series.
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* Setting this value will automatically set the type to "custom".
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* The value is an empty array when the type is not "custom".
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* @memberOf Tone.Oscillator#
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* @type {Array}
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* @name partials
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* @example
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* osc.partials = [1, 0.2, 0.01];
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*/
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Object.defineProperty(Tone.Oscillator.prototype, "partials", {
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get : function(){
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if (this._type !== Tone.Oscillator.Type.Custom){
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return [];
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} else {
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return this._partials;
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}
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},
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set : function(partials){
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this._partials = partials;
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this.type = Tone.Oscillator.Type.Custom;
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}
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});
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/**
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* The phase of the oscillator in degrees.
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* @memberOf Tone.Oscillator#
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* @type {Degrees}
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* @name phase
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* @example
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* osc.phase = 180; //flips the phase of the oscillator
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*/
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Object.defineProperty(Tone.Oscillator.prototype, "phase", {
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get : function(){
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return this._phase * (180 / Math.PI);
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},
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set : function(phase){
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this._phase = phase * Math.PI / 180;
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//reset the type
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this.type = this._type;
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}
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});
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/**
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* Dispose and disconnect.
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* @return {Tone.Oscillator} this
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*/
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Tone.Oscillator.prototype.dispose = function(){
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Tone.Source.prototype.dispose.call(this);
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if (this._oscillator !== null){
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this._oscillator.disconnect();
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this._oscillator = null;
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}
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this._wave = null;
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this._writable(["frequency", "detune"]);
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this.frequency.dispose();
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this.frequency = null;
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this.detune.dispose();
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this.detune = null;
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this._partials = null;
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return this;
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};
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return Tone.Oscillator;
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});
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