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7.js
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7.js
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function thereminOn(oscillator, oscillator2) {
oscillator.play();
oscillator2.play();
}
function thereminControl(e, oscillator, oscillator2, theremin, urlParameters) {
let x = e.offsetX;
let y = e.offsetY;
console.log(x, y);
let minFrequency = 220.0;
let maxFrequency = 880.0;
let notename = document.getElementById('notename')
let frequency = document.getElementById('frequency')
let notename2 = document.getElementById('notename2')
let frequency2 = document.getElementById('frequency2')
let freqRange = maxFrequency - minFrequency;
let thereminFreq = minFrequency + (x / theremin.clientWidth) * freqRange;
let thereminVolume = 1.0 - (y / theremin.clientHeight);
console.log("Frequency: ", thereminFreq);
oscillator.frequency = thereminFreq;
notename.innerHTML = noteFromFrequency(thereminFreq);
frequency.innerHTML = thereminFreq;
if (urlParameters.has('semitones')) {
let semitones = parseInt(urlParameters.get('semitones'));
oscillator2.frequency = interval(thereminFreq, semitones);
notename2.innerHTML = noteFromFrequency(oscillator2.frequency);
frequency2.innerHTML = oscillator2.frequency;
} else {
oscillator2.frequency = 0;
}
console.log("Frequency2: ", oscillator2.frequency);
console.log("Volume: ", thereminVolume);
oscillator.volume = thereminVolume;
oscillator2.volume = thereminVolume;
}
function thereminOff(oscillator, oscillator2) {
oscillator.stop();
oscillator2.stop();
}
function runAfterLoadingPage() {
let oscillatorType = "sine";
let urlParameters = (new URL(document.location)).searchParams;
if (urlParameters.has('osctype')) {
oscillatorType = urlParameters.get('osctype');
}
if (urlParameters.has('minfreq')) {
minfreq = parseInt(urlParameters.get('minfreq'));
}
if (urlParameters.has('maxfreq')) {
maxfreq = parseInt(urlParameters.get('maxfreq'));
}
const oscillator = new Pizzicato.Sound({
source: 'wave',
options: {
type: oscillatorType,
frequency: 220
}
});
const oscillator2 = new Pizzicato.Sound({
source: 'wave',
options: {
type: oscillatorType,
frequency: 220
}
});
const theremin = document.getElementById("thereminZone");
theremin.addEventListener("mouseenter", function (e) {
thereminOn(oscillator, oscillator2);
});
theremin.addEventListener("mousemove", function (e) {
thereminControl(e, oscillator, oscillator2, theremin, urlParameters);
});
theremin.addEventListener("mouseleave", function () {
thereminOff(oscillator, oscillator2);
});
}
let notenames = {
0: "C",
1: "C#/Db",
2: "D",
3: "D#/Eb",
4: "E",
5: "F",
6: "F#/Gb",
7: "G",
8: "G#/Ab",
9: "A",
10: "A#/Bb",
11: "B"
}
function interval(frequency, semitones) {
return frequency * Math.pow(2, semitones / 12);
}
function midiToFrequency(midinumber, concertA = 440) {
const A4 = 69
if (midinumber === A4) {
return concertA;
}
let semitones = midinumber - A4;
return interval(440, semitones);
}
function midiFromFrequency(frequency) {
let minDiff = Number.MAX_VALUE;
let midinumber = -1;
for (let midi = 0; midi < 128; midi++) {
let midiFreq = midiToFrequency(midi);
let freqDiff = Math.abs(midiFreq - frequency);
if (freqDiff < minDiff) {
minDiff = freqDiff;
midinumber = midi;
}
}
return midinumber
}
function noteFromFrequency(frequency, withOctave=false) {
const midinumber = midiFromFrequency(frequency);
const pitchclass = midinumber % 12;
let octave = (midinumber - pitchclass) / 12;
let notename = notenames[pitchclass];
if (withOctave) {
octave--;
notename += octave;
}
return notename;
}
window.onload = runAfterLoadingPage;