Tone.js/Tone/core/context/Gain.ts
2020-07-26 13:55:06 -07:00

90 lines
2.5 KiB
TypeScript

import { Param } from "../context/Param";
import { UnitMap, UnitName } from "../type/Units";
import { optionsFromArguments } from "../util/Defaults";
import { readOnly } from "../util/Interface";
import { ToneAudioNode, ToneAudioNodeOptions } from "./ToneAudioNode";
interface GainOptions<TypeName extends UnitName> extends ToneAudioNodeOptions {
gain: UnitMap[TypeName];
units: TypeName;
convert: boolean;
minValue?: number;
maxValue?: number;
}
/**
* A thin wrapper around the Native Web Audio GainNode.
* The GainNode is a basic building block of the Web Audio
* API and is useful for routing audio and adjusting gains.
* @category Core
* @example
* return Tone.Offline(() => {
* const gainNode = new Tone.Gain(0).toDestination();
* const osc = new Tone.Oscillator(30).connect(gainNode).start();
* gainNode.gain.rampTo(1, 0.1);
* gainNode.gain.rampTo(0, 0.4, 0.2);
* }, 0.7, 1);
*/
export class Gain<TypeName extends "gain" | "decibels" | "normalRange" = "gain"> extends ToneAudioNode<GainOptions<TypeName>> {
readonly name: string = "Gain";
/**
* The gain parameter of the gain node.
* @example
* const gainNode = new Tone.Gain(0).toDestination();
* const osc = new Tone.Oscillator().connect(gainNode).start();
* gainNode.gain.rampTo(1, 0.1);
* gainNode.gain.rampTo(0, 2, "+0.5");
*/
readonly gain: Param<TypeName>;
/**
* The wrapped GainNode.
*/
private _gainNode: GainNode = this.context.createGain();
// input = output
readonly input: GainNode = this._gainNode;
readonly output: GainNode = this._gainNode;
/**
* @param gain The initial gain of the GainNode
* @param units The units of the gain parameter.
*/
constructor(gain?: UnitMap[TypeName], units?: TypeName);
constructor(options?: Partial<GainOptions<TypeName>>);
constructor() {
super(optionsFromArguments(Gain.getDefaults(), arguments, ["gain", "units"]));
const options = optionsFromArguments(Gain.getDefaults(), arguments, ["gain", "units"]);
this.gain = new Param({
context: this.context,
convert: options.convert,
param: this._gainNode.gain,
units: options.units,
value: options.gain,
minValue: options.minValue,
maxValue: options.maxValue,
});
readOnly(this, "gain");
}
static getDefaults(): GainOptions<any> {
return Object.assign(ToneAudioNode.getDefaults(), {
convert: true,
gain: 1,
units: "gain",
});
}
/**
* Clean up.
*/
dispose(): this {
super.dispose();
this._gainNode.disconnect();
this.gain.dispose();
return this;
}
}