mirror of
https://github.com/Tonejs/Tone.js
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89 lines
2.8 KiB
JavaScript
89 lines
2.8 KiB
JavaScript
///////////////////////////////////////////////////////////////////////////////
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//
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// Envelope
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//
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// ADR envelope generator attaches to an AudioParam
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///////////////////////////////////////////////////////////////////////////////
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define(["Tone/core/Tone"], function(Tone){
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Tone.Envelope = function(attack, decay, sustain, release, audioParam, minOutput, maxOutput){
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//extend Unit
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Tone.call(this);
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//pass audio through
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this.input.connect(this.output);
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//set the parameters
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this.param = this.defaultArg(audioParam, this.input.gain);
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this.attack = this.defaultArg(attack, .01);
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this.decay = this.defaultArg(decay, .1);
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this.release = this.defaultArg(release, 1);
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this.sustain = this.defaultArg(.5);
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// this.setSustain(this.defaultArg(sustain, .1));
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this.min = this.defaultArg(minOutput, 0);
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this.max = this.defaultArg(maxOutput, 1);
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//set the initial value
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this.param.value = this.min;
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}
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Tone.extend(Tone.Envelope, Tone);
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//attack->decay->sustain
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Tone.Envelope.prototype.triggerAttack = function(time){
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var startVal = this.min;
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if (!time){
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startVal = this.param.value;
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}
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time = this.defaultArg(time, this.now());
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this.param.cancelScheduledValues(time);
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this.param.setValueAtTime(startVal, time);
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this.param.linearRampToValueAtTime(this.max, time + this.attack);
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var sustainVal = (this.max - this.min) * this.sustain + this.min;
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this.param.linearRampToValueAtTime(sustainVal, time + this.decay + this.attack);
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}
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//attack->decay->sustain
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Tone.Envelope.prototype.triggerAttackExp = function(time){
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var startVal = this.min;
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if (!time){
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startVal = this.param.value;
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}
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time = this.defaultArg(time, this.now());
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this.param.cancelScheduledValues(time);
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this.param.setValueAtTime(startVal, time);
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this.param.exponentialRampToValueAtTime(this.max, time + this.attack);
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var sustainVal = (this.max - this.min) * this.sustain + this.min;
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this.param.exponentialRampToValueAtTime(sustainVal, time + this.decay + this.attack);
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}
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//triggers the release of the envelope
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Tone.Envelope.prototype.triggerRelease = function(time){
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var startVal = this.param.value;
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if (time){
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startVal = (this.max - this.min) * this.sustain + this.min;
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}
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time = this.defaultArg(time, this.now());
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this.param.cancelScheduledValues(time);
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this.param.setValueAtTime(startVal, time);
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this.param.linearRampToValueAtTime(this.min, time + this.release);
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}
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//triggers the release of the envelope
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Tone.Envelope.prototype.triggerReleaseExp = function(time){
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var startVal = this.param.value;
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if (time){
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startVal = (this.max - this.min) * this.sustain + this.min;
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}
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time = this.defaultArg(time, this.now());
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this.param.cancelScheduledValues(time);
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this.param.setValueAtTime(startVal, time);
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this.param.exponentialRampToValueAtTime(this.min, time + this.release);
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}
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return Tone.Envelope;
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});
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