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pitched delay

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This commit is contained in:
Jade (Rose) Rowland 2025-06-10 12:31:21 +02:00
parent 3963b807eb
commit 7e8206dcbc
2 changed files with 46 additions and 18 deletions
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45
packages/supradough/dough.mjs
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@ -44,6 +44,7 @@ function polyBlep(t, dt) {
// 0 otherwise
return 0;
}
export class SawOsc {
constructor(props = {}) {
this.phase = props.phase ?? 0;
@ -349,21 +350,31 @@ export class ADSR {
.out()*/
const MAX_DELAY_TIME = 10;
export class Delay {
writeIdx = 0;
readIdx = 0;
buffer = new Float32Array(MAX_DELAY_TIME * SAMPLE_RATE); //.fill(0)
write(s, delayTime) {
this.writeIdx = (this.writeIdx + 1) % this.buffer.length;
this.buffer[this.writeIdx] = s;
// Calculate how far in the past to read
let numSamples = Math.min(Math.floor(SAMPLE_RATE * delayTime), this.buffer.length - 1);
this.readIdx = this.writeIdx - numSamples;
// If past the start of the buffer, wrap around
if (this.readIdx < 0) this.readIdx += this.buffer.length;
constructor(_props = {}) {
this.buffer = new Float32Array(MAX_DELAY_TIME * SAMPLE_RATE);
this.writeIdx = 0;
this.readIdx = 0;
this.numSamples = 0;
}
update(input, delayTime) {
write(s, delayTime) {
// Calculate how far in the past to read
this.numSamples = Math.min(Math.floor(SAMPLE_RATE * delayTime), this.buffer.length - 1);
this.writeIdx = (this.writeIdx + 1) % this.numSamples;
this.buffer[this.writeIdx] = s;
this.readIdx = this.writeIdx - this.numSamples + 1;
// If past the start of the buffer, wrap around (Q: is this possible?)
if (this.readIdx < 0) this.readIdx += this.numSamples;
}
update(input, delayTime, speed = 1) {
this.write(input, delayTime);
return this.buffer[this.readIdx];
let index = this.readIdx;
if (speed < 0) {
index = this.numSamples - Math.floor(Math.abs(this.readIdx * speed) % this.numSamples);
} else {
index = Math.floor(this.readIdx * speed) % this.numSamples;
}
return this.buffer[index];
}
}
@ -550,6 +561,7 @@ const defaultDefaultValues = {
delay: 0,
byteBeatExpression: '0',
delayfeedback: 0.5,
delayspeed: 1,
delaytime: 0.25,
orbit: 1,
i: 1,
@ -662,6 +674,7 @@ export class DoughVoice {
// delay
$.delay = applyGainCurve($.delay ?? getDefaultValue('delay'));
$.delayfeedback = $.delayfeedback ?? getDefaultValue('delayfeedback');
$.delayspeed = $.delayspeed ?? getDefaultValue('delayspeed');
$.delaytime = $.delaytime ?? getDefaultValue('delaytime');
// precalculated values
@ -822,6 +835,7 @@ export class Dough {
delaysend = [0, 0];
delaytime = getDefaultValue('delaytime');
delayfeedback = getDefaultValue('delayfeedback');
delayspeed = getDefaultValue('delayspeed');
t = 0;
// sampleRate: number, currentTime: number (seconds)
constructor(sampleRate = 48000, currentTime = 0) {
@ -897,12 +911,13 @@ export class Dough {
this.delaysend[0] += this.voices[v].out[0] * this.voices[v].delay;
this.delaysend[1] += this.voices[v].out[1] * this.voices[v].delay;
this.delaytime = this.voices[v].delaytime; // we trust that these are initialized in the voice
this.delayspeed = this.voices[v].delayspeed; // we trust that these are initialized in the voice
this.delayfeedback = this.voices[v].delayfeedback;
}
}
// todo: how to change delaytime / delayfeedback from a voice?
const delayL = this._delayL.update(this.delaysend[0], this.delaytime);
const delayR = this._delayR.update(this.delaysend[1], this.delaytime);
const delayL = this._delayL.update(this.delaysend[0], this.delaytime, this.delayspeed);
const delayR = this._delayR.update(this.delaysend[1], this.delaytime, this.delayspeed);
this.delaysend[0] = delayL * this.delayfeedback;
this.delaysend[1] = delayR * this.delayfeedback;
this.out[0] += delayL;