Tone.js/Tone/component/LFO.js

///////////////////////////////////////////////////////////////////////////////
//
//  LFO
//
///////////////////////////////////////////////////////////////////////////////

define(["Tone/core/Tone", "Tone/source/Oscillator", "Tone/signal/Scale"], function(Tone){

	Tone.LFO = function(rate, outputMin, outputMax){
		//extends Unit
		Tone.call(this);

		//defaults
		rate = this.defaultArg(rate, 1);
		min = this.defaultArg(outputMin, -1);
		max = this.defaultArg(outputMax, 1);

		//the components
		this.oscillator = new Tone.Oscillator(rate, "sine");
		this.scaler = new Tone.Scale(min, max);

		//connect it up
		this.chain(this.oscillator, this.scaler, this.output);
	}

	Tone.extend(Tone.LFO, Tone);


	//start the lfo
	Tone.LFO.prototype.start = function(time){
		this.oscillator.start(time);
	}

	//stop
	Tone.LFO.prototype.stop = function(time){
		this.oscillator.stop(time);
	}


	//set the params
	Tone.LFO.prototype.setFrequency = function(rate){
		this.oscillator.setFrequency(rate);
	}

	//set the params
	Tone.LFO.prototype.setMin = function(min){
		this.scaler.setMin(min);
	}

	//set the params
	Tone.LFO.prototype.setMax = function(max){
		this.scaler.setMax(max);
	}

	//set the waveform of the LFO
	//@param {string | number} type ('sine', 'square', 'sawtooth', 'triangle', 'custom');
	Tone.LFO.prototype.setType = function(type){
		this.oscillator.setType(type);
	}

	//@private
	//pointer to the parent's connect method
	Tone.LFO.prototype._connect = Tone.prototype.connect;

	//triggers the release of the envelope
	Tone.LFO.prototype.connect = function(param){
		if (param instanceof AudioParam){
			//set the initial value
			param.value = this.scaler.min;
		} 
		this._connect(param);
	}

	return Tone.LFO;
});