hacklab/strudel
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

exponential lerp

Browse source
This commit is contained in:
Jade (Rose) Rowland 2025-06-08 19:24:55 +02:00
parent b000f2297d
commit ec9109dd89
1 changed files with 28 additions and 10 deletions
Download patch file Download diff file Expand all files Collapse all files

38
packages/supradough/dough.mjs
View file

@ -192,16 +192,30 @@ export class Hold {
}
}
function lerp(x, y0, y1) {
function lerp(x, y0, y1, exponent = 1) {
if (x <= 0) return y0;
if (x >= 1) return y1;
return y0 + x * (y1 - y0);
let curvedX;
if (exponent === 0) {
curvedX = x; // linear
} else if (exponent > 0) {
curvedX = Math.pow(x, exponent); // ease-in
} else {
curvedX = 1 - Math.pow(1 - x, -exponent); // ease-out
}
return y0 + (y1 - y0) * curvedX;
}
export class ADSR {
state = 'off';
startTime = 0;
startVal = 0;
constructor(props = {}) {
this.state = 'off'
this.startTime = 0;
this.startVal = 0;
this.curve = props.curve ?? 1;
}
update(curTime, gate, attack, decay, susVal, release) {
switch (this.state) {
@ -220,11 +234,11 @@ export class ADSR {
this.startTime = curTime;
return 1;
}
return lerp(time / attack, this.startVal, 1);
return lerp(time / attack, this.startVal, 1, this.curve);
}
case 'decay': {
let time = curTime - this.startTime;
let curVal = lerp(time / decay, 1, susVal);
let curVal = lerp(time / decay, 1, susVal, -this.curve);
if (gate <= 0) {
this.state = 'release';
this.startTime = curTime;
@ -253,7 +267,7 @@ export class ADSR {
this.state = 'off';
return 0;
}
let curVal = lerp(time / release, this.startVal, 0);
let curVal = lerp(time / release, this.startVal, 0, -this.curve);
if (gate > 0) {
this.state = 'attack';
this.startTime = curTime;
@ -564,6 +578,7 @@ export class DoughVoice {
this.fmsustain,
this.fmrelease,
]);
}
}
@ -571,7 +586,9 @@ export class DoughVoice {
this._lpf = this.cutoff ? new TwoPoleFilter() : null;
this.resonance = this.resonance ?? getDefaultValue('resonance');
if (this.lpenv) {
this._lpenv = new ADSR();
this._lpenv = new ADSR({curve: 4});
[this.lpattack, this.lpdecay, this.lpsustain, this.lprelease] = getADSRValues([
this.lpattack,
this.lpdecay,
@ -584,6 +601,7 @@ export class DoughVoice {
this.hresonance = this.hresonance ?? getDefaultValue('hresonance');
if (this.hpenv) {
this._hpenv = new ADSR();
[this.hpattack, this.hpdecay, this.hpsustain, this.hprelease] = getADSRValues([
this.hpattack,
this.hpdecay,
@ -604,7 +622,7 @@ export class DoughVoice {
}
// gain envelope
this._adsr = new ADSR();
this._adsr = new ADSR({curve: 2});
// fx setup
this._coarse = this.coarse ? new Coarse() : null;