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89 lines
2.9 KiB
JavaScript
89 lines
2.9 KiB
JavaScript
// credits to webdirt: https://github.com/dktr0/WebDirt/blob/41342e81d6ad694a2310d491fef7b7e8b0929efe/js-src/Graph.js#L597
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export var vowelFormant = {
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0: { freqs: [660, 1120, 2750, 3000, 3350], gains: [1, 0.5012, 0.0708, 0.0631, 0.0126], qs: [80, 90, 120, 130, 140] },
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1: { freqs: [440, 1800, 2700, 3000, 3300], gains: [1, 0.1995, 0.1259, 0.1, 0.1], qs: [70, 80, 100, 120, 120] },
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2: { freqs: [270, 1850, 2900, 3350, 3590], gains: [1, 0.0631, 0.0631, 0.0158, 0.0158], qs: [40, 90, 100, 120, 120] },
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3: { freqs: [430, 820, 2700, 3000, 3300], gains: [1, 0.3162, 0.0501, 0.0794, 0.01995], qs: [40, 80, 100, 120, 120] },
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4: { freqs: [370, 630, 2750, 3000, 3400], gains: [1, 0.1, 0.0708, 0.0316, 0.01995], qs: [40, 60, 100, 120, 120] },
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};
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var createFilter = function (ctx, cutoff, Q) {
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var lowpassFilter = ctx.createBiquadFilter();
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lowpassFilter.type = 'notch';
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lowpassFilter.gain.value = 1;
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lowpassFilter.frequency.value = cutoff;
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lowpassFilter.Q.value = Q;
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return lowpassFilter;
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};
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// var createTriOscillator = function (freq) {
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// var osc = ctx.createOscillator();
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// osc.type = 'triangle';
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// osc.frequency.value = freq * 1.0;
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// osc.detune.value = 0;
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// return osc;
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// };
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var createLFO = function (ctx, freq) {
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var osc = ctx.createOscillator();
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osc.frequency.value = freq;
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osc.type = 'sine';
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osc.start();
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return osc;
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};
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var createLFOGain = function (ctx, gain) {
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var gainNode = ctx.createGain();
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gainNode.gain.value = gain;
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return gainNode;
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};
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let lfo, lfoGain;
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if (typeof GainNode !== 'undefined') {
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class PhaserNode extends GainNode {
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constructor(ac, speed) {
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super(ac);
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console.log('speed', speed);
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if (!vowelFormant[speed]) {
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throw new Error('phaser: unknown phaser ' + speed);
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}
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const { gains, qs, freqs } = vowelFormant[speed];
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const makeupGain = ac.createGain();
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// var sine = ac.createOscillator(),
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// sineGain = ac.createGain();
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// //set up our oscillator types
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// sine.type = sine.SINE;
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// //set the amplitude of the modulation
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// sineGain.gain.value = 100;
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// //connect the dots
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// sine.connect(sineGain);
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if (lfo == null) {
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lfo = createLFO(ac, 0.25);
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lfoGain = createLFOGain(ac, 4000);
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lfo.connect(lfoGain);
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}
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// sineGain.connect(saw.frequency);
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for (let i = 0; i < 6; i++) {
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const gain = ac.createGain();
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gain.gain.value = 0.5;
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const filter = createFilter(ac, 1000 + i * 20, 1);
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this.connect(filter);
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lfoGain.connect(filter.detune);
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filter.connect(gain);
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gain.connect(makeupGain);
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}
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makeupGain.gain.value = 1; // how much makeup gain to add?
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this.connect = (target) => makeupGain.connect(target);
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return this;
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}
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}
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AudioContext.prototype.createPhaser = function (speed) {
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return new PhaserNode(this, speed);
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};
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}
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