Tone.js/Tone/component/LFO.js
2016-05-14 18:07:53 -04:00

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8.4 KiB
JavaScript

define(["Tone/core/Tone", "Tone/source/Oscillator", "Tone/signal/Scale",
"Tone/signal/Signal", "Tone/signal/AudioToGain", "Tone/type/Type", "Tone/signal/Zero"],
function(Tone){
"use strict";
/**
* @class LFO stands for low frequency oscillator. Tone.LFO produces an output signal
* which can be attached to an AudioParam or Tone.Signal
* in order to modulate that parameter with an oscillator. The LFO can
* also be synced to the transport to start/stop and change when the tempo changes.
*
* @constructor
* @extends {Tone.Oscillator}
* @param {Frequency|Object} [frequency] The frequency of the oscillation. Typically, LFOs will be
* in the frequency range of 0.1 to 10 hertz.
* @param {number=} min The minimum output value of the LFO.
* @param {number=} max The maximum value of the LFO.
* @example
* var lfo = new Tone.LFO("4n", 400, 4000);
* lfo.connect(filter.frequency);
*/
Tone.LFO = function(){
var options = this.optionsObject(arguments, ["frequency", "min", "max"], Tone.LFO.defaults);
/**
* The oscillator.
* @type {Tone.Oscillator}
* @private
*/
this._oscillator = new Tone.Oscillator({
"frequency" : options.frequency,
"type" : options.type,
});
/**
* the lfo's frequency
* @type {Frequency}
* @signal
*/
this.frequency = this._oscillator.frequency;
/**
* The amplitude of the LFO, which controls the output range between
* the min and max output. For example if the min is -10 and the max
* is 10, setting the amplitude to 0.5 would make the LFO modulate
* between -5 and 5.
* @type {Number}
* @signal
*/
this.amplitude = this._oscillator.volume;
this.amplitude.units = Tone.Type.NormalRange;
this.amplitude.value = options.amplitude;
/**
* The signal which is output when the LFO is stopped
* @type {Tone.Signal}
* @private
*/
this._stoppedSignal = new Tone.Signal(0, Tone.Type.AudioRange);
/**
* Just outputs zeros.
* @type {Tone.Zero}
* @private
*/
this._zeros = new Tone.Zero();
/**
* The value that the LFO outputs when it's stopped
* @type {AudioRange}
* @private
*/
this._stoppedValue = 0;
/**
* @type {Tone.AudioToGain}
* @private
*/
this._a2g = new Tone.AudioToGain();
/**
* @type {Tone.Scale}
* @private
*/
this._scaler = this.output = new Tone.Scale(options.min, options.max);
/**
* the units of the LFO (used for converting)
* @type {Tone.Type}
* @private
*/
this._units = Tone.Type.Default;
this.units = options.units;
//connect it up
this._oscillator.chain(this._a2g, this._scaler);
this._zeros.connect(this._a2g);
this._stoppedSignal.connect(this._a2g);
this._readOnly(["amplitude", "frequency"]);
this.phase = options.phase;
};
Tone.extend(Tone.LFO, Tone.Oscillator);
/**
* the default parameters
*
* @static
* @const
* @type {Object}
*/
Tone.LFO.defaults = {
"type" : "sine",
"min" : 0,
"max" : 1,
"phase" : 0,
"frequency" : "4n",
"amplitude" : 1,
"units" : Tone.Type.Default
};
/**
* Start the LFO.
* @param {Time} [time=now] the time the LFO will start
* @returns {Tone.LFO} this
*/
Tone.LFO.prototype.start = function(time){
time = this.toSeconds(time);
this._stoppedSignal.setValueAtTime(0, time);
this._oscillator.start(time);
return this;
};
/**
* Stop the LFO.
* @param {Time} [time=now] the time the LFO will stop
* @returns {Tone.LFO} this
*/
Tone.LFO.prototype.stop = function(time){
time = this.toSeconds(time);
this._stoppedSignal.setValueAtTime(this._stoppedValue, time);
this._oscillator.stop(time);
return this;
};
/**
* Sync the start/stop/pause to the transport
* and the frequency to the bpm of the transport
*
* @param {Time} [delay=0] the time to delay the start of the
* LFO from the start of the transport
* @returns {Tone.LFO} this
* @example
* lfo.frequency.value = "8n";
* lfo.sync();
* //the rate of the LFO will always be an eighth note,
* //even as the tempo changes
*/
Tone.LFO.prototype.sync = function(delay){
this._oscillator.sync(delay);
this._oscillator.syncFrequency();
return this;
};
/**
* unsync the LFO from transport control
* @returns {Tone.LFO} this
*/
Tone.LFO.prototype.unsync = function(){
this._oscillator.unsync();
this._oscillator.unsyncFrequency();
return this;
};
/**
* The miniumum output of the LFO.
* @memberOf Tone.LFO#
* @type {number}
* @name min
*/
Object.defineProperty(Tone.LFO.prototype, "min", {
get : function(){
return this._toUnits(this._scaler.min);
},
set : function(min){
min = this._fromUnits(min);
this._scaler.min = min;
}
});
/**
* The maximum output of the LFO.
* @memberOf Tone.LFO#
* @type {number}
* @name max
*/
Object.defineProperty(Tone.LFO.prototype, "max", {
get : function(){
return this._toUnits(this._scaler.max);
},
set : function(max){
max = this._fromUnits(max);
this._scaler.max = max;
}
});
/**
* The type of the oscillator: sine, square, sawtooth, triangle.
* @memberOf Tone.LFO#
* @type {string}
* @name type
*/
Object.defineProperty(Tone.LFO.prototype, "type", {
get : function(){
return this._oscillator.type;
},
set : function(type){
this._oscillator.type = type;
this._stoppedValue = this._oscillator._getInitialValue();
this._stoppedSignal.value = this._stoppedValue;
}
});
/**
* The phase of the LFO.
* @memberOf Tone.LFO#
* @type {number}
* @name phase
*/
Object.defineProperty(Tone.LFO.prototype, "phase", {
get : function(){
return this._oscillator.phase;
},
set : function(phase){
this._oscillator.phase = phase;
this._stoppedValue = this._oscillator._getInitialValue();
this._stoppedSignal.value = this._stoppedValue;
}
});
/**
* The output units of the LFO.
* @memberOf Tone.LFO#
* @type {Tone.Type}
* @name units
*/
Object.defineProperty(Tone.LFO.prototype, "units", {
get : function(){
return this._units;
},
set : function(val){
var currentMin = this.min;
var currentMax = this.max;
//convert the min and the max
this._units = val;
this.min = currentMin;
this.max = currentMax;
}
});
/**
* Mute the output.
* @memberOf Tone.LFO#
* @type {Boolean}
* @name mute
*/
Object.defineProperty(Tone.LFO.prototype, "mute", {
get : function(){
return this._oscillator.mute;
},
set : function(mute){
this._oscillator.mute = mute;
}
});
/**
* Returns the playback state of the source, either "started" or "stopped".
* @type {Tone.State}
* @readOnly
* @memberOf Tone.LFO#
* @name state
*/
Object.defineProperty(Tone.LFO.prototype, "state", {
get : function(){
return this._oscillator.state;
}
});
/**
* Connect the output of the LFO to an AudioParam, AudioNode, or Tone Node.
* Tone.LFO will automatically convert to the destination units of the
* will get the units from the connected node.
* @param {Tone | AudioParam | AudioNode} node
* @param {number} [outputNum=0] optionally which output to connect from
* @param {number} [inputNum=0] optionally which input to connect to
* @returns {Tone.LFO} this
* @private
*/
Tone.LFO.prototype.connect = function(node){
if (node.constructor === Tone.Signal || node.constructor === Tone.Param || node.constructor === Tone.TimelineSignal){
this.convert = node.convert;
this.units = node.units;
}
Tone.Signal.prototype.connect.apply(this, arguments);
return this;
};
/**
* private method borrowed from Param converts
* units from their destination value
* @function
* @private
*/
Tone.LFO.prototype._fromUnits = Tone.Param.prototype._fromUnits;
/**
* private method borrowed from Param converts
* units to their destination value
* @function
* @private
*/
Tone.LFO.prototype._toUnits = Tone.Param.prototype._toUnits;
/**
* disconnect and dispose
* @returns {Tone.LFO} this
*/
Tone.LFO.prototype.dispose = function(){
Tone.prototype.dispose.call(this);
this._writable(["amplitude", "frequency"]);
this._oscillator.dispose();
this._oscillator = null;
this._stoppedSignal.dispose();
this._stoppedSignal = null;
this._zeros.dispose();
this._zeros = null;
this._scaler.dispose();
this._scaler = null;
this._a2g.dispose();
this._a2g = null;
this.frequency = null;
this.amplitude = null;
return this;
};
return Tone.LFO;
});