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Initial work on crackle

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This commit is contained in:
Raphael Forment 2023-11-17 12:55:17 +01:00
parent 49aa9cf6da
commit 476bda812e
2 changed files with 15 additions and 6 deletions
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17
packages/superdough/noise.mjs
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@ -4,7 +4,7 @@ import { getAudioContext } from './superdough.mjs';
let noiseCache = {}; let noiseCache = {};
// lazy generates noise buffers and keeps them forever // lazy generates noise buffers and keeps them forever
function getNoiseBuffer(type) { function getNoiseBuffer(type, density) {
const ac = getAudioContext(); const ac = getAudioContext();
if (noiseCache[type]) { if (noiseCache[type]) {
return noiseCache[type]; return noiseCache[type];
@ -34,17 +34,26 @@ function getNoiseBuffer(type) {
output[i] = b0 + b1 + b2 + b3 + b4 + b5 + b6 + white * 0.5362; output[i] = b0 + b1 + b2 + b3 + b4 + b5 + b6 + white * 0.5362;
output[i] *= 0.11; output[i] *= 0.11;
b6 = white * 0.115926; b6 = white * 0.115926;
} else if (type === 'crackle') {
if (Math.random() < (Math.random() * (density - 0.001) + density).toFixed(4)) {
output[i] = Math.random() * 2 - 1;
} else {
output[i] = 0;
}
} }
} }
noiseCache[type] = noiseBuffer;
// Prevent caching to randomize crackles
if (type !== "crackle")
noiseCache[type] = noiseBuffer;
return noiseBuffer; return noiseBuffer;
} }
// expects one of noises as type // expects one of noises as type
export function getNoiseOscillator(type = 'white', t) { export function getNoiseOscillator(type = 'white', t, density = 0.02) {
const ac = getAudioContext(); const ac = getAudioContext();
const o = ac.createBufferSource(); const o = ac.createBufferSource();
o.buffer = getNoiseBuffer(type); o.buffer = getNoiseBuffer(type, density);
o.loop = true; o.loop = true;
o.start(t); o.start(t);
return { return {

4
packages/superdough/synth.mjs
View file

@ -22,7 +22,7 @@ const fm = (osc, harmonicityRatio, modulationIndex, wave = 'sine') => {
}; };
const waveforms = ['sine', 'square', 'triangle', 'sawtooth']; const waveforms = ['sine', 'square', 'triangle', 'sawtooth'];
const noises = ['pink', 'white', 'brown']; const noises = ['pink', 'white', 'brown', 'crackle'];
export function registerSynthSounds() { export function registerSynthSounds() {
[...waveforms, ...noises].forEach((s) => { [...waveforms, ...noises].forEach((s) => {
@ -36,7 +36,7 @@ export function registerSynthSounds() {
if (waveforms.includes(s)) { if (waveforms.includes(s)) {
sound = getOscillator(s, t, value); sound = getOscillator(s, t, value);
} else { } else {
sound = getNoiseOscillator(s, t); sound = getNoiseOscillator(s, t, 0.002);
} }
let { node: o, stop, triggerRelease } = sound; let { node: o, stop, triggerRelease } = sound;