tone
Version:
A Web Audio framework for making interactive music in the browser.
193 lines • 6.71 kB
JavaScript
import * as tslib_1 from "tslib";
import { Gain } from "../../core/context/Gain";
import { optionsFromArguments } from "../../core/util/Defaults";
import { readOnly } from "../../core/util/Interface";
import { Signal } from "../../signal/Signal";
import { WaveShaper } from "../../signal/WaveShaper";
import { Source } from "../Source";
import { Oscillator } from "./Oscillator";
import { generateWaveform } from "./OscillatorInterface";
/**
* PulseOscillator is an oscillator with control over pulse width,
* also known as the duty cycle. At 50% duty cycle (width = 0) the wave is
* a square wave.
* [Read more](https://wigglewave.wordpress.com/2014/08/16/pulse-waveforms-and-harmonics/).
* ```
* width = -0.25 width = 0.0 width = 0.25
*
* +-----+ +-------+ + +-------+ +-+
* | | | | | | |
* | | | | | | |
* +-+ +-------+ + +-------+ +-----+
*
*
* width = -0.5 width = 0.5
*
* +---+ +-------+ +---+
* | | | |
* | | | |
* +---+ +-------+ +---+
*
*
* width = -0.75 width = 0.75
*
* +-+ +-------+ +-----+
* | | | |
* | | | |
* +-----+ +-------+ +-+
* ```
* @example
* import { PulseOscillator } from "tone";
* const pulse = new PulseOscillator("E5", 0.4).toDestination().start();
* @category Source
*/
var PulseOscillator = /** @class */ (function (_super) {
tslib_1.__extends(PulseOscillator, _super);
function PulseOscillator() {
var _this = _super.call(this, optionsFromArguments(PulseOscillator.getDefaults(), arguments, ["frequency", "width"])) || this;
_this.name = "PulseOscillator";
/**
* gate the width amount
*/
_this._widthGate = new Gain({
context: _this.context,
gain: 0,
});
/**
* Threshold the signal to turn it into a square
*/
_this._thresh = new WaveShaper({
context: _this.context,
mapping: function (val) { return val <= 0 ? -1 : 1; },
});
var options = optionsFromArguments(PulseOscillator.getDefaults(), arguments, ["frequency", "width"]);
_this.width = new Signal({
context: _this.context,
units: "audioRange",
value: options.width,
});
_this._sawtooth = new Oscillator({
context: _this.context,
detune: options.detune,
frequency: options.frequency,
onstop: function () { return _this.onstop(_this); },
phase: options.phase,
type: "sawtooth",
});
_this.frequency = _this._sawtooth.frequency;
_this.detune = _this._sawtooth.detune;
// connections
_this._sawtooth.chain(_this._thresh, _this.output);
_this.width.chain(_this._widthGate, _this._thresh);
readOnly(_this, ["width", "frequency", "detune"]);
return _this;
}
PulseOscillator.getDefaults = function () {
return Object.assign(Source.getDefaults(), {
detune: 0,
frequency: 440,
phase: 0,
type: "pulse",
width: 0.2,
});
};
/**
* start the oscillator
*/
PulseOscillator.prototype._start = function (time) {
time = this.toSeconds(time);
this._sawtooth.start(time);
this._widthGate.gain.setValueAtTime(1, time);
};
/**
* stop the oscillator
*/
PulseOscillator.prototype._stop = function (time) {
time = this.toSeconds(time);
this._sawtooth.stop(time);
// the width is still connected to the output.
// that needs to be stopped also
this._widthGate.gain.cancelScheduledValues(time);
this._widthGate.gain.setValueAtTime(0, time);
};
PulseOscillator.prototype._restart = function (time) {
this._sawtooth.restart(time);
this._widthGate.gain.cancelScheduledValues(time);
this._widthGate.gain.setValueAtTime(1, time);
};
Object.defineProperty(PulseOscillator.prototype, "phase", {
/**
* The phase of the oscillator in degrees.
*/
get: function () {
return this._sawtooth.phase;
},
set: function (phase) {
this._sawtooth.phase = phase;
},
enumerable: true,
configurable: true
});
Object.defineProperty(PulseOscillator.prototype, "type", {
/**
* The type of the oscillator. Always returns "pulse".
*/
get: function () {
return "pulse";
},
enumerable: true,
configurable: true
});
Object.defineProperty(PulseOscillator.prototype, "baseType", {
/**
* The baseType of the oscillator. Always returns "pulse".
*/
get: function () {
return "pulse";
},
enumerable: true,
configurable: true
});
Object.defineProperty(PulseOscillator.prototype, "partials", {
/**
* The partials of the waveform. Cannot set partials for this waveform type
*/
get: function () {
return [];
},
enumerable: true,
configurable: true
});
Object.defineProperty(PulseOscillator.prototype, "partialCount", {
/**
* No partials for this waveform type.
*/
get: function () {
return 0;
},
enumerable: true,
configurable: true
});
PulseOscillator.prototype.asArray = function (length) {
if (length === void 0) { length = 1024; }
return tslib_1.__awaiter(this, void 0, void 0, function () {
return tslib_1.__generator(this, function (_a) {
return [2 /*return*/, generateWaveform(this, length)];
});
});
};
/**
* Clean up method.
*/
PulseOscillator.prototype.dispose = function () {
_super.prototype.dispose.call(this);
this._sawtooth.dispose();
this.width.dispose();
this._widthGate.dispose();
this._thresh.dispose();
return this;
};
return PulseOscillator;
}(Source));
export { PulseOscillator };
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