Vibrato Effect

LFO attached to a Delay

Tone/effect/Vibrato.js

@@ -0,0 +1,100 @@
+define(["Tone/core/Tone", "Tone/effect/Effect", "Tone/core/Delay", "Tone/component/LFO"], function (Tone) {
+
+	/**
+	 *  @class A Vibrato effect composed of a Tone.Delay and a Tone.LFO. The LFO
+	 *         modulates the delayTime of the delay, causing the pitch to rise
+	 *         and fall. 
+	 *  @extends {Tone.Effect}
+	 *  @param {Frequency} frequency The frequency of the vibrato.
+	 *  @param {NormalRange} depth The amount the pitch is modulated.
+	 */
+	Tone.Vibrato = function(){
+
+		var options = this.optionsObject(arguments, ["frequency", "depth"], Tone.Vibrato.defaults);
+		Tone.Effect.call(this, options);
+
+		/**
+		 *  The delay node used for the vibrato effect
+		 *  @type {Tone.Delay}
+		 *  @private
+		 */
+		this._delayNode = new Tone.Delay(options.maxDelay);
+
+		/**
+		 *  The LFO used to control the vibrato
+		 *  @type {Tone.LFO}
+		 *  @private
+		 */
+		this._lfo = new Tone.LFO({
+			"type" : options.type,
+			"min" : 0,
+			"max" : options.maxDelay, 
+			"frequency"  : options.frequency,
+			"phase" : -90 //offse the phase so the resting position is in the center
+		}).start().connect(this._delayNode.delayTime);
+
+		/**
+		 *  The frequency of the vibrato
+		 *  @type {Frequency}
+		 *  @signal
+		 */
+		this.frequency = this._lfo.frequency;
+
+		/**
+		 *  The depth of the vibrato. 
+		 *  @type {NormalRange}
+		 *  @signal
+		 */
+		this.depth = this._lfo.amplitude;
+
+		this.depth.value = options.depth;
+		this._readOnly(["frequency", "depth"]);
+		this.effectSend.chain(this._delayNode, this.effectReturn);
+	};
+
+	Tone.extend(Tone.Vibrato, Tone.Effect);
+
+	/**
+	 *  The defaults
+	 *  @type  {Object}
+	 *  @const
+	 */
+	Tone.Vibrato.defaults = {
+		"maxDelay" : 0.005,
+		"frequency" : 5,
+		"depth" : 0.1,
+		"type" : "sine"
+	};
+
+	/**
+	 * Type of oscillator attached to the Vibrato.
+	 * @memberOf Tone.Vibrato#
+	 * @type {string}
+	 * @name type
+	 */
+	Object.defineProperty(Tone.Vibrato.prototype, "type", {
+		get : function(){
+			return this._lfo.type;
+		},
+		set : function(type){
+			this._lfo.type = type;
+		}
+	});
+
+	/**
+	 *  Clean up.
+	 *  @returns {Tone.Vibrato} this
+	 */
+	Tone.Vibrato.prototype.dispose = function(){
+		Tone.Effect.prototype.dispose.call(this);
+		this._delayNode.dispose();
+		this._delayNode = null;
+		this._lfo.dispose();
+		this._lfo = null;
+		this._writable(["frequency", "depth"]);
+		this.frequency = null;
+		this.depth = null;
+	};
+
+	return Tone.Vibrato;
+});