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exponential lerp

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Jade (Rose) Rowland 2025-06-08 19:24:55 +02:00
parent b000f2297d
commit ec9109dd89
1 changed files with 28 additions and 10 deletions
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38
packages/supradough/dough.mjs
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@ -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; 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 { export class ADSR {
state = 'off'; constructor(props = {}) {
startTime = 0; this.state = 'off'
startVal = 0; this.startTime = 0;
this.startVal = 0;
this.curve = props.curve ?? 1;
}
update(curTime, gate, attack, decay, susVal, release) { update(curTime, gate, attack, decay, susVal, release) {
switch (this.state) { switch (this.state) {
@ -220,11 +234,11 @@ export class ADSR {
this.startTime = curTime; this.startTime = curTime;
return 1; return 1;
} }
return lerp(time / attack, this.startVal, 1); return lerp(time / attack, this.startVal, 1, this.curve);
} }
case 'decay': { case 'decay': {
let time = curTime - this.startTime; let time = curTime - this.startTime;
let curVal = lerp(time / decay, 1, susVal); let curVal = lerp(time / decay, 1, susVal, -this.curve);
if (gate <= 0) { if (gate <= 0) {
this.state = 'release'; this.state = 'release';
this.startTime = curTime; this.startTime = curTime;
@ -253,7 +267,7 @@ export class ADSR {
this.state = 'off'; this.state = 'off';
return 0; return 0;
} }
let curVal = lerp(time / release, this.startVal, 0); let curVal = lerp(time / release, this.startVal, 0, -this.curve);
if (gate > 0) { if (gate > 0) {
this.state = 'attack'; this.state = 'attack';
this.startTime = curTime; this.startTime = curTime;
@ -564,6 +578,7 @@ export class DoughVoice {
this.fmsustain, this.fmsustain,
this.fmrelease, this.fmrelease,
]); ]);
} }
} }
@ -571,7 +586,9 @@ export class DoughVoice {
this._lpf = this.cutoff ? new TwoPoleFilter() : null; this._lpf = this.cutoff ? new TwoPoleFilter() : null;
this.resonance = this.resonance ?? getDefaultValue('resonance'); this.resonance = this.resonance ?? getDefaultValue('resonance');
if (this.lpenv) { 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, this.lpsustain, this.lprelease] = getADSRValues([
this.lpattack, this.lpattack,
this.lpdecay, this.lpdecay,
@ -584,6 +601,7 @@ export class DoughVoice {
this.hresonance = this.hresonance ?? getDefaultValue('hresonance'); this.hresonance = this.hresonance ?? getDefaultValue('hresonance');
if (this.hpenv) { if (this.hpenv) {
this._hpenv = new ADSR(); this._hpenv = new ADSR();
[this.hpattack, this.hpdecay, this.hpsustain, this.hprelease] = getADSRValues([ [this.hpattack, this.hpdecay, this.hpsustain, this.hprelease] = getADSRValues([
this.hpattack, this.hpattack,
this.hpdecay, this.hpdecay,
@ -604,7 +622,7 @@ export class DoughVoice {
} }
// gain envelope // gain envelope
this._adsr = new ADSR(); this._adsr = new ADSR({curve: 2});
// fx setup // fx setup
this._coarse = this.coarse ? new Coarse() : null; this._coarse = this.coarse ? new Coarse() : null;