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April 21, 2019 23:21
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// Copyright 2012, Google Inc. | |
// All rights reserved. | |
// | |
// Redistribution and use in source and binary forms, with or without | |
// modification, are permitted provided that the following conditions are | |
// met: | |
// | |
// * Redistributions of source code must retain the above copyright | |
// notice, this list of conditions and the following disclaimer. | |
// * Redistributions in binary form must reproduce the above | |
// copyright notice, this list of conditions and the following disclaimer | |
// in the documentation and/or other materials provided with the | |
// distribution. | |
// * Neither the name of Google Inc. nor the names of its | |
// contributors may be used to endorse or promote products derived from | |
// this software without specific prior written permission. | |
// | |
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
function createFadeBuffer(context, activeTime, fadeTime) { | |
var length1 = activeTime * context.sampleRate; | |
var length2 = (activeTime - 2*fadeTime) * context.sampleRate; | |
var length = length1 + length2; | |
var buffer = context.createBuffer(1, length, context.sampleRate); | |
var p = buffer.getChannelData(0); | |
console.log("createFadeBuffer() length = " + length); | |
var fadeLength = fadeTime * context.sampleRate; | |
var fadeIndex1 = fadeLength; | |
var fadeIndex2 = length1 - fadeLength; | |
// 1st part of cycle | |
for (var i = 0; i < length1; ++i) { | |
var value; | |
if (i < fadeIndex1) { | |
value = Math.sqrt(i / fadeLength); | |
} else if (i >= fadeIndex2) { | |
value = Math.sqrt(1 - (i - fadeIndex2) / fadeLength); | |
} else { | |
value = 1; | |
} | |
p[i] = value; | |
} | |
// 2nd part | |
for (var i = length1; i < length; ++i) { | |
p[i] = 0; | |
} | |
return buffer; | |
} | |
function createDelayTimeBuffer(context, activeTime, fadeTime, shiftUp) { | |
var length1 = activeTime * context.sampleRate; | |
var length2 = (activeTime - 2*fadeTime) * context.sampleRate; | |
var length = length1 + length2; | |
var buffer = context.createBuffer(1, length, context.sampleRate); | |
var p = buffer.getChannelData(0); | |
console.log("createDelayTimeBuffer() length = " + length); | |
// 1st part of cycle | |
for (var i = 0; i < length1; ++i) { | |
if (shiftUp) | |
// This line does shift-up transpose | |
p[i] = (length1-i)/length; | |
else | |
// This line does shift-down transpose | |
p[i] = i / length1; | |
} | |
// 2nd part | |
for (var i = length1; i < length; ++i) { | |
p[i] = 0; | |
} | |
return buffer; | |
} | |
var delayTime = 0.100; | |
var fadeTime = 0.050; | |
var bufferTime = 0.100; | |
function Jungle(context) { | |
this.context = context; | |
// Create nodes for the input and output of this "module". | |
var input = context.createGain(); | |
var output = context.createGain(); | |
this.input = input; | |
this.output = output; | |
// Delay modulation. | |
var mod1 = context.createBufferSource(); | |
var mod2 = context.createBufferSource(); | |
var mod3 = context.createBufferSource(); | |
var mod4 = context.createBufferSource(); | |
this.shiftDownBuffer = createDelayTimeBuffer(context, bufferTime, fadeTime, false); | |
this.shiftUpBuffer = createDelayTimeBuffer(context, bufferTime, fadeTime, true); | |
mod1.buffer = this.shiftDownBuffer; | |
mod2.buffer = this.shiftDownBuffer; | |
mod3.buffer = this.shiftUpBuffer; | |
mod4.buffer = this.shiftUpBuffer; | |
mod1.loop = true; | |
mod2.loop = true; | |
mod3.loop = true; | |
mod4.loop = true; | |
// for switching between oct-up and oct-down | |
var mod1Gain = context.createGain(); | |
var mod2Gain = context.createGain(); | |
var mod3Gain = context.createGain(); | |
mod3Gain.gain.value = 0; | |
var mod4Gain = context.createGain(); | |
mod4Gain.gain.value = 0; | |
mod1.connect(mod1Gain); | |
mod2.connect(mod2Gain); | |
mod3.connect(mod3Gain); | |
mod4.connect(mod4Gain); | |
// Delay amount for changing pitch. | |
var modGain1 = context.createGain(); | |
var modGain2 = context.createGain(); | |
var delay1 = context.createDelay(); | |
var delay2 = context.createDelay(); | |
mod1Gain.connect(modGain1); | |
mod2Gain.connect(modGain2); | |
mod3Gain.connect(modGain1); | |
mod4Gain.connect(modGain2); | |
modGain1.connect(delay1.delayTime); | |
modGain2.connect(delay2.delayTime); | |
// Crossfading. | |
var fade1 = context.createBufferSource(); | |
var fade2 = context.createBufferSource(); | |
var fadeBuffer = createFadeBuffer(context, bufferTime, fadeTime); | |
fade1.buffer = fadeBuffer | |
fade2.buffer = fadeBuffer; | |
fade1.loop = true; | |
fade2.loop = true; | |
var mix1 = context.createGain(); | |
var mix2 = context.createGain(); | |
mix1.gain.value = 0; | |
mix2.gain.value = 0; | |
fade1.connect(mix1.gain); | |
fade2.connect(mix2.gain); | |
// Connect processing graph. | |
input.connect(delay1); | |
input.connect(delay2); | |
delay1.connect(mix1); | |
delay2.connect(mix2); | |
mix1.connect(output); | |
mix2.connect(output); | |
// Start | |
var t = context.currentTime + 0.050; | |
var t2 = t + bufferTime - fadeTime; | |
mod1.start(t); | |
mod2.start(t2); | |
mod3.start(t); | |
mod4.start(t2); | |
fade1.start(t); | |
fade2.start(t2); | |
this.mod1 = mod1; | |
this.mod2 = mod2; | |
this.mod1Gain = mod1Gain; | |
this.mod2Gain = mod2Gain; | |
this.mod3Gain = mod3Gain; | |
this.mod4Gain = mod4Gain; | |
this.modGain1 = modGain1; | |
this.modGain2 = modGain2; | |
this.fade1 = fade1; | |
this.fade2 = fade2; | |
this.mix1 = mix1; | |
this.mix2 = mix2; | |
this.delay1 = delay1; | |
this.delay2 = delay2; | |
this.setDelay(delayTime); | |
} | |
Jungle.prototype.setDelay = function(delayTime) { | |
this.modGain1.gain.setTargetAtTime(0.5*delayTime, 0, 0.010); | |
this.modGain2.gain.setTargetAtTime(0.5*delayTime, 0, 0.010); | |
} | |
var previousPitch = -1; | |
Jungle.prototype.setPitchOffset = function(mult) { | |
if (mult>0) { // pitch up | |
this.mod1Gain.gain.value = 0; | |
this.mod2Gain.gain.value = 0; | |
this.mod3Gain.gain.value = 1; | |
this.mod4Gain.gain.value = 1; | |
} else { // pitch down | |
this.mod1Gain.gain.value = 1; | |
this.mod2Gain.gain.value = 1; | |
this.mod3Gain.gain.value = 0; | |
this.mod4Gain.gain.value = 0; | |
} | |
this.setDelay(delayTime*Math.abs(mult)); | |
previousPitch = mult; | |
} | |
Jungle.prototype.mapPitchFromSemitone = function(e) { | |
if (e < 0) | |
return e / 12; | |
switch (e) { | |
case 0: | |
return 0; | |
case 1: | |
return .15; | |
case 2: | |
return .2396498469723199; | |
case 3: | |
return .3392416223392665; | |
case 4: | |
return .5240613184290452; | |
case 5: | |
return .6938443526464626; | |
case 6: | |
return .8531707712586548; | |
case 7: | |
return 1.0062309336345026; | |
case 8: | |
return 1.1572897600301169; | |
case 9: | |
return 1.3572897600301168; | |
case 10: | |
return 1.5356230933634503; | |
case 11: | |
return 1.7056230933634502; | |
case 12: | |
return 2; | |
default: | |
return 0 | |
} | |
} | |
, | |
Jungle.prototype.setPitchTranspose = function(e, a) { | |
a = parseInt(a), | |
e = parseFloat(e); | |
var t = this.mapPitchFromSemitone(a) + 1 * e / 12; | |
this.setPitchOffset(t) | |
} |
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