tone
Version:
A Web Audio framework for making interactive music in the browser.
100 lines • 3.62 kB
JavaScript
import { optionsFromArguments } from "../core/util/Defaults.js";
import { isArray, isFunction } from "../core/util/TypeCheck.js";
import { assert } from "../core/util/Debug.js";
import { Signal } from "./Signal.js";
import { SignalOperator } from "./SignalOperator.js";
/**
* Wraps the native Web Audio API
* [WaveShaperNode](http://webaudio.github.io/web-audio-api/#the-waveshapernode-interface).
*
* @example
* const osc = new Tone.Oscillator().toDestination().start();
* // multiply the output of the signal by 2 using the waveshaper's function
* const timesTwo = new Tone.WaveShaper((val) => val * 2, 2048).connect(osc.frequency);
* const signal = new Tone.Signal(440).connect(timesTwo);
* @category Signal
*/
export class WaveShaper extends SignalOperator {
constructor() {
const options = optionsFromArguments(WaveShaper.getDefaults(), arguments, ["mapping", "length"]);
super(options);
this.name = "WaveShaper";
/**
* the waveshaper node
*/
this._shaper = this.context.createWaveShaper();
/**
* The input to the waveshaper node.
*/
this.input = this._shaper;
/**
* The output from the waveshaper node
*/
this.output = this._shaper;
if (isArray(options.mapping) ||
options.mapping instanceof Float32Array) {
this.curve = Float32Array.from(options.mapping);
}
else if (isFunction(options.mapping)) {
this.setMap(options.mapping, options.length);
}
}
static getDefaults() {
return Object.assign(Signal.getDefaults(), {
length: 1024,
});
}
/**
* Uses a mapping function to set the value of the curve.
* @param mapping The function used to define the values.
* The mapping function take two arguments:
* the first is the value at the current position
* which goes from -1 to 1 over the number of elements
* in the curve array. The second argument is the array position.
* @example
* const shaper = new Tone.WaveShaper();
* // map the input signal from [-1, 1] to [0, 10]
* shaper.setMap((val, index) => (val + 1) * 5);
*/
setMap(mapping, length = 1024) {
const array = new Float32Array(length);
for (let i = 0, len = length; i < len; i++) {
const normalized = (i / (len - 1)) * 2 - 1;
array[i] = mapping(normalized, i);
}
this.curve = array;
return this;
}
/**
* The array to set as the waveshaper curve. For linear curves
* array length does not make much difference, but for complex curves
* longer arrays will provide smoother interpolation.
*/
get curve() {
return this._shaper.curve;
}
set curve(mapping) {
this._shaper.curve = mapping;
}
/**
* Specifies what type of oversampling (if any) should be used when
* applying the shaping curve. Can either be "none", "2x" or "4x".
*/
get oversample() {
return this._shaper.oversample;
}
set oversample(oversampling) {
const isOverSampleType = ["none", "2x", "4x"].some((str) => str.includes(oversampling));
assert(isOverSampleType, "oversampling must be either 'none', '2x', or '4x'");
this._shaper.oversample = oversampling;
}
/**
* Clean up.
*/
dispose() {
super.dispose();
this._shaper.disconnect();
return this;
}
}
//# sourceMappingURL=WaveShaper.js.map