Tone.js/Tone/effect/AutoPanner.js

import Tone from "../core/Tone";
import "../effect/Effect";
import "../component/LFO";
import "../component/Panner";

/**
 *  @class Tone.AutoPanner is a Tone.Panner with an LFO connected to the pan amount. 
 *         More on using autopanners [here](https://www.ableton.com/en/blog/autopan-chopper-effect-and-more-liveschool/).
 *
 *  @constructor
 *  @extends {Tone.Effect}
 *  @param {Frequency|Object} [frequency] Rate of left-right oscillation. 
 *  @example
 * //create an autopanner and start it's LFO
 * var autoPanner = new Tone.AutoPanner("4n").toMaster().start();
 * //route an oscillator through the panner and start it
 * var oscillator = new Tone.Oscillator().connect(autoPanner).start();
 */
Tone.AutoPanner = function(){

	var options = Tone.defaults(arguments, ["frequency"], Tone.AutoPanner);
	Tone.Effect.call(this, options);

	/**
	 *  the lfo which drives the panning
	 *  @type {Tone.LFO}
	 *  @private
	 */
	this._lfo = new Tone.LFO({
		"frequency" : options.frequency,
		"amplitude" : options.depth,
		"min" : -1,
		"max" : 1,
	});

	/**
	 * The amount of panning between left and right. 
	 * 0 = always center. 1 = full range between left and right. 
	 * @type {NormalRange}
	 * @signal
	 */
	this.depth = this._lfo.amplitude;

	/**
	 *  the panner node which does the panning
	 *  @type {Tone.Panner}
	 *  @private
	 */
	this._panner = new Tone.Panner();

	/**
	 * How fast the panner modulates between left and right. 
	 * @type {Frequency}
	 * @signal
	 */
	this.frequency = this._lfo.frequency;

	//connections
	this.connectEffect(this._panner);
	this._lfo.connect(this._panner.pan);
	this.type = options.type;
	this._readOnly(["depth", "frequency"]);
};

//extend Effect
Tone.extend(Tone.AutoPanner, Tone.Effect);

/**
 *  defaults
 *  @static
 *  @type {Object}
 */
Tone.AutoPanner.defaults = {
	"frequency" : 1,
	"type" : "sine",
	"depth" : 1
};

/**
 * Start the effect.
 * @param {Time} [time=now] When the LFO will start. 
 * @returns {Tone.AutoPanner} this
 */
Tone.AutoPanner.prototype.start = function(time){
	this._lfo.start(time);
	return this;
};

/**
 * Stop the effect.
 * @param {Time} [time=now] When the LFO will stop. 
 * @returns {Tone.AutoPanner} this
 */
Tone.AutoPanner.prototype.stop = function(time){
	this._lfo.stop(time);
	return this;
};

/**
 * Sync the panner to the transport.
 * @param {Time} [delay=0] Delay time before starting the effect after the
 *                               Transport has started. 
 * @returns {Tone.AutoPanner} this
 */
Tone.AutoPanner.prototype.sync = function(delay){
	this._lfo.sync(delay);
	return this;
};

/**
 * Unsync the panner from the transport
 * @returns {Tone.AutoPanner} this
 */
Tone.AutoPanner.prototype.unsync = function(){
	this._lfo.unsync();
	return this;
};

/**
 * Type of oscillator attached to the AutoFilter. 
 * Possible values: "sine", "square", "triangle", "sawtooth".
 * @memberOf Tone.AutoFilter#
 * @type {string}
 * @name type
 */
Object.defineProperty(Tone.AutoPanner.prototype, "type", {
	get : function(){
		return this._lfo.type;
	},
	set : function(type){
		this._lfo.type = type;
	}
});

/**
 *  clean up
 *  @returns {Tone.AutoPanner} this
 */
Tone.AutoPanner.prototype.dispose = function(){
	Tone.Effect.prototype.dispose.call(this);
	this._lfo.dispose();
	this._lfo = null;
	this._panner.dispose();
	this._panner = null;
	this._writable(["depth", "frequency"]);
	this.frequency = null;
	this.depth = null;
	return this;
};

export default Tone.AutoPanner;