Tone.js/Tone/instrument/PluckSynth.ts
2019-09-24 17:21:59 -04:00

113 lines
2.7 KiB
TypeScript

import { Param } from "../core/context/Param";
import { Frequency, NormalRange, Time } from "../core/type/Units";
import { LowpassCombFilter } from "../component/filter/LowpassCombFilter";
import { deepMerge } from "../core/util/Defaults";
import { optionsFromArguments } from "../core/util/Defaults";
import { RecursivePartial } from "../core/util/Interface";
import { Signal } from "../signal/Signal";
import { Noise } from "../source/Noise";
import { Instrument, InstrumentOptions } from "./Instrument";
export interface PluckSynthOptions extends InstrumentOptions {
attackNoise: number;
dampening: Frequency;
resonance: NormalRange;
}
/**
* Karplus-String string synthesis. Often out of tune.
*
* @example
* var plucky = new Tone.PluckSynth().toDestination();
* plucky.triggerAttack("C4");
* @category Instrument
*/
export class PluckSynth extends Instrument<PluckSynthOptions> {
readonly name = "PluckSynth";
/**
* Noise burst at the beginning
*/
private _noise: Noise;
private _lfcf: LowpassCombFilter;
/**
* The amount of noise at the attack.
* Nominal range of [0.1, 20]
* @min 0.1
* @max 20
*/
attackNoise: number;
/**
* The resonance control.
*/
readonly resonance: Param<NormalRange>;
/**
* The dampening control. i.e. the lowpass filter frequency of the comb filter
* @min 0
* @max 7000
*/
readonly dampening: Signal<Frequency>;
constructor(options?: RecursivePartial<PluckSynthOptions>)
constructor() {
super(optionsFromArguments(PluckSynth.getDefaults(), arguments));
const options = optionsFromArguments(PluckSynth.getDefaults(), arguments);
this._noise = new Noise({
context: this.context,
type: "pink"
});
this.attackNoise = options.attackNoise;
this._lfcf = new LowpassCombFilter({
context: this.context,
dampening: options.dampening,
resonance: options.resonance,
});
this.resonance = this._lfcf.resonance;
this.dampening = this._lfcf.dampening;
this._noise.connect(this._lfcf);
this._lfcf.connect(this.output);
}
static getDefaults(): PluckSynthOptions {
return deepMerge(Instrument.getDefaults(), {
attackNoise: 1,
dampening: 4000,
resonance: 0.7,
});
}
triggerAttack(note: Frequency, time?: Time): this {
const freq = this.toFrequency(note);
time = this.toSeconds(time);
const delayAmount = 1 / freq;
this._lfcf.delayTime.setValueAtTime(delayAmount, time);
this._noise.start(time);
this._noise.stop(time + delayAmount * this.attackNoise);
return this;
}
/**
* PluckSynths' trigger release method doesn't do anything.
*/
triggerRelease(): this{
// does nothing
return this;
}
dispose(): this {
super.dispose();
this._noise.dispose();
this._lfcf.dispose();
return this;
}
}