Tone.js/Tone/signal/Modulo.js

import Tone from "../core/Tone";
import "../signal/WaveShaper";
import "../signal/Multiply";
import "../signal/Subtract";

/**
 *  @class Signal-rate modulo operator. Only works in AudioRange [-1, 1] and for modulus
 *         values in the NormalRange.
 *
 *  @constructor
 *  @extends {Tone.SignalBase}
 *  @param {NormalRange} modulus The modulus to apply.
 *  @example
 * var mod = new Tone.Modulo(0.2)
 * var sig = new Tone.Signal(0.5).connect(mod);
 * //mod outputs 0.1
 */
Tone.Modulo = function(modulus){

	Tone.SignalBase.call(this);
	this.createInsOuts(1, 0);

	/**
	 *  A waveshaper gets the integer multiple of
	 *  the input signal and the modulus.
	 *  @private
	 *  @type {Tone.WaveShaper}
	 */
	this._shaper = new Tone.WaveShaper(Math.pow(2, 16));

	/**
	 *  the integer multiple is multiplied by the modulus
	 *  @type  {Tone.Multiply}
	 *  @private
	 */
	this._multiply = new Tone.Multiply();

	/**
	 *  and subtracted from the input signal
	 *  @type  {Tone.Subtract}
	 *  @private
	 */
	this._subtract = this.output = new Tone.Subtract();

	/**
	 *  the modulus signal
	 *  @type  {Tone.Signal}
	 *  @private
	 */
	this._modSignal = new Tone.Signal(modulus);

	//connections
	Tone.connect(this.input, this._shaper);
	Tone.connect(this.input, this._subtract);
	this._modSignal.connect(this._multiply, 0, 0);
	this._shaper.connect(this._multiply, 0, 1);
	this._multiply.connect(this._subtract, 0, 1);
	this._setWaveShaper(modulus);
};

Tone.extend(Tone.Modulo, Tone.SignalBase);

/**
 *  @param  {number}  mod  the modulus to apply
 *  @private
 */
Tone.Modulo.prototype._setWaveShaper = function(mod){
	this._shaper.setMap(function(val){
		var multiple = Math.floor((val + 0.0001) / mod);
		return multiple;
	});
};

/**
 * The modulus value.
 * @memberOf Tone.Modulo#
 * @type {NormalRange}
 * @name value
 */
Object.defineProperty(Tone.Modulo.prototype, "value", {
	get : function(){
		return this._modSignal.value;
	},
	set : function(mod){
		this._modSignal.value = mod;
		this._setWaveShaper(mod);
	}
});

/**
 * clean up
 *  @returns {Tone.Modulo} this
 */
Tone.Modulo.prototype.dispose = function(){
	Tone.SignalBase.prototype.dispose.call(this);
	this._shaper.dispose();
	this._shaper = null;
	this._multiply.dispose();
	this._multiply = null;
	this._subtract.dispose();
	this._subtract = null;
	this._modSignal.dispose();
	this._modSignal = null;
	return this;
};

export default Tone.Modulo;