| 1 | import { Effect } from "./Effect.js";
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| 2 | import { optionsFromArguments } from "../core/util/Defaults.js";
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| 3 | import { WaveShaper } from "../signal/WaveShaper.js";
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| 4 | import { assert } from "../core/util/Debug.js";
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| 5 | /**
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| 6 | * Chebyshev is a waveshaper which is good
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| 7 | * for making different types of distortion sounds.
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| 8 | * Note that odd orders sound very different from even ones,
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| 9 | * and order = 1 is no change.
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| 10 | * Read more at [music.columbia.edu](http://music.columbia.edu/cmc/musicandcomputers/chapter4/04_06.php).
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| 11 | * @example
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| 12 | * // create a new cheby
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| 13 | * const cheby = new Tone.Chebyshev(50).toDestination();
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| 14 | * // create a monosynth connected to our cheby
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| 15 | * const synth = new Tone.MonoSynth().connect(cheby);
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| 16 | * synth.triggerAttackRelease("C2", 0.4);
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| 17 | * @category Effect
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| 18 | */
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| 19 | export class Chebyshev extends Effect {
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| 20 | constructor() {
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| 21 | const options = optionsFromArguments(Chebyshev.getDefaults(), arguments, ["order"]);
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| 22 | super(options);
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| 23 | this.name = "Chebyshev";
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| 24 | this._shaper = new WaveShaper({
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| 25 | context: this.context,
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| 26 | length: 4096,
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| 27 | });
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| 28 | this._order = options.order;
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| 29 | this.connectEffect(this._shaper);
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| 30 | this.order = options.order;
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| 31 | this.oversample = options.oversample;
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| 32 | }
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| 33 | static getDefaults() {
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| 34 | return Object.assign(Effect.getDefaults(), {
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| 35 | order: 1,
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| 36 | oversample: "none",
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| 37 | });
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| 38 | }
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| 39 | /**
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| 40 | * get the coefficient for that degree
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| 41 | * @param x the x value
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| 42 | * @param degree
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| 43 | * @param memo memoize the computed value. this speeds up computation greatly.
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| 44 | */
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| 45 | _getCoefficient(x, degree, memo) {
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| 46 | if (memo.has(degree)) {
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| 47 | return memo.get(degree);
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| 48 | }
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| 49 | else if (degree === 0) {
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| 50 | memo.set(degree, 0);
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| 51 | }
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| 52 | else if (degree === 1) {
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| 53 | memo.set(degree, x);
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| 54 | }
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| 55 | else {
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| 56 | memo.set(degree, 2 * x * this._getCoefficient(x, degree - 1, memo) -
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| 57 | this._getCoefficient(x, degree - 2, memo));
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| 58 | }
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| 59 | return memo.get(degree);
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| 60 | }
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| 61 | /**
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| 62 | * The order of the Chebyshev polynomial which creates the equation which is applied to the incoming
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| 63 | * signal through a Tone.WaveShaper. Must be an integer. The equations are in the form:
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| 64 | * ```
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| 65 | * order 2: 2x^2 + 1
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| 66 | * order 3: 4x^3 + 3x
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| 67 | * ```
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| 68 | * @min 1
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| 69 | * @max 100
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| 70 | */
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| 71 | get order() {
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| 72 | return this._order;
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| 73 | }
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| 74 | set order(order) {
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| 75 | assert(Number.isInteger(order), "'order' must be an integer");
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| 76 | this._order = order;
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| 77 | this._shaper.setMap((x) => {
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| 78 | return this._getCoefficient(x, order, new Map());
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| 79 | });
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| 80 | }
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| 81 | /**
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| 82 | * The oversampling of the effect. Can either be "none", "2x" or "4x".
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| 83 | */
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| 84 | get oversample() {
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| 85 | return this._shaper.oversample;
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| 86 | }
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| 87 | set oversample(oversampling) {
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| 88 | this._shaper.oversample = oversampling;
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| 89 | }
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| 90 | dispose() {
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| 91 | super.dispose();
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| 92 | this._shaper.dispose();
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| 93 | return this;
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| 94 | }
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| 95 | }
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| 96 | //# sourceMappingURL=Chebyshev.js.map |
| \ | No newline at end of file |