Tone.js/Tone/effect/MidSideEffect.js
2015-02-02 13:22:16 -05:00

112 lines
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3 KiB
JavaScript

define(["Tone/core/Tone", "Tone/effect/StereoEffect"], function(Tone){
"use strict";
/**
* @class Applies a Mid/Side seperation and recombination
* http://musicdsp.org/showArchiveComment.php?ArchiveID=173
* http://www.kvraudio.com/forum/viewtopic.php?t=212587
* M = (L+R)/sqrt(2); // obtain mid-signal from left and right
* S = (L-R)/sqrt(2); // obtain side-signal from left and righ
* // amplify mid and side signal seperately:
* M/S send/return
* L = (M+S)/sqrt(2); // obtain left signal from mid and side
* R = (M-S)/sqrt(2); // obtain right signal from mid and side
*
* @extends {Tone.StereoEffect}
* @constructor
*/
Tone.MidSideEffect = function(){
Tone.StereoEffect.call(this);
/**
* a constant signal equal to 1 / sqrt(2)
* @type {Tone.Signal}
* @private
*/
this._sqrtTwo = new Tone.Signal(1 / Math.sqrt(2));
/**
* the mid send.
* connect to mid processing
* @type {Tone.Expr}
*/
this.midSend = new Tone.Expr("($0 + $1) * $2");
/**
* the side send.
* connect to side processing
* @type {Tone.Expr}
*/
this.sideSend = new Tone.Expr("($0 - $1) * $2");
/**
* recombine the mid/side into Left
* @type {Tone.Expr}
* @private
*/
this._left = new Tone.Expr("($0 + $1) * $2");
/**
* recombine the mid/side into Right
* @type {Tone.Expr}
* @private
*/
this._right = new Tone.Expr("($0 - $1) * $2");
/**
* the mid return connection
* @type {GainNode}
*/
this.midReturn = this.context.createGain();
/**
* the side return connection
* @type {GainNode}
*/
this.sideReturn = this.context.createGain();
//connections
this.effectSendL.connect(this.midSend, 0, 0);
this.effectSendR.connect(this.midSend, 0, 1);
this.effectSendL.connect(this.sideSend, 0, 0);
this.effectSendR.connect(this.sideSend, 0, 1);
this._left.connect(this.effectReturnL);
this._right.connect(this.effectReturnR);
this.midReturn.connect(this._left, 0, 0);
this.sideReturn.connect(this._left, 0, 1);
this.midReturn.connect(this._right, 0, 0);
this.sideReturn.connect(this._right, 0, 1);
this._sqrtTwo.connect(this.midSend, 0, 2);
this._sqrtTwo.connect(this.sideSend, 0, 2);
this._sqrtTwo.connect(this._left, 0, 2);
this._sqrtTwo.connect(this._right, 0, 2);
};
Tone.extend(Tone.MidSideEffect, Tone.StereoEffect);
/**
* clean up
* @returns {Tone.MidSideEffect} `this`
*/
Tone.MidSideEffect.prototype.dispose = function(){
Tone.StereoEffect.prototype.dispose.call(this);
this._sqrtTwo.dispose();
this._sqrtTwo = null;
this.midSend.dispose();
this.midSend = null;
this.sideSend.dispose();
this.sideSend = null;
this._left.dispose();
this._left = null;
this._right.dispose();
this._right = null;
this.midReturn.disconnect();
this.midReturn = null;
this.sideReturn.disconnect();
this.sideReturn = null;
return this;
};
return Tone.MidSideEffect;
});