First pass at modes

packages/core/controls.mjs

@@ -1575,7 +1575,7 @@ export const { roomsize, size, sz, rsize } = registerControl('roomsize', 'size',
 export const { shape } = registerControl(['shape', 'shapevol']);
 /**
  * Wave shaping distortion. CAUTION: it can get loud.
- * Second option in optional array syntax (ex: ".9:.5") applies a postgain to the output.
+ * Second option in optional array syntax (ex: ".9:.5") applies a postgain to the output. Third option sets the waveshaping type.
  * Most useful values are usually between 0 and 10 (depending on source gain). If you are feeling adventurous, you can turn it up to 11 and beyond ;)
  *
  * @name distort
@@ -1585,9 +1585,40 @@ export const { shape } = registerControl(['shape', 'shapevol']);
  * s("bd sd [~ bd] sd,hh*8").distort("<0 2 3 10:.5>")
  * @example
  * note("d1!8").s("sine").penv(36).pdecay(.12).decay(.23).distort("8:.4")
+ * @example
+ * s("bd*4").bank("tr909").distort("4:0.5:fold")
  *
  */
-export const { distort, dist } = registerControl(['distort', 'distortvol'], 'dist');
+export const { distort, dist } = registerControl(['distort', 'distortvol', 'distorttype'], 'dist');
+
+/**
+ * Postgain for waveshaping distortion.
+ *
+ * @name distortvol
+ * @synonyms distvol
+ * @param {number | Pattern} type
+ * @example
+ * s("bd*4").bank("tr909").distort(2).distortvol(0.8)
+ */
+export const { distortvol } = registerControl('distortvol', 'distvol');
+
+/**
+ * Type of waveshaping distortion to apply.
+ *
+ * @name distorttype
+ * @synonyms disttype
+ * @param {number | string | Pattern} type
+ * @example
+ * s("bd*4").bank("tr909").distort(2).distorttype("<0 1 2>")
+ *
+ * @example
+ * s("sine").note("F1*2").release(1)
+ *   .penv(24).pdecay(0.05)
+ *   .distort(70)
+ *   .distorttype("<fold decimate scurve hard soft diode asym>")
+ */
+export const { distorttype } = registerControl('distorttype', 'disttype');
+
 /**
  * Dynamics Compressor. The params are `compressor("threshold:ratio:knee:attack:release")`
  * More info [here](https://developer.mozilla.org/en-US/docs/Web/API/DynamicsCompressorNode?retiredLocale=de#instance_properties)

packages/superdough/helpers.mjs

@@ -307,3 +307,7 @@ export function applyFM(param, value, begin) {
   }
   return { stop };
 }
+
+export const getDistortion = (distort, postgain, algorithm) => {
+  return getWorklet(getAudioContext(), 'distort-processor', { distort, postgain, algorithm });
+};

packages/superdough/superdough.mjs

@@ -9,7 +9,7 @@ import './reverb.mjs';
 import './vowel.mjs';
 import { clamp, nanFallback, _mod, cycleToSeconds, secondsToCycle } from './util.mjs';
 import workletsUrl from './worklets.mjs?audioworklet';
-import { createFilter, gainNode, getCompressor, getWorklet, webAudioTimeout } from './helpers.mjs';
+import { createFilter, gainNode, getCompressor, getDistortion, getWorklet, webAudioTimeout } from './helpers.mjs';
 import { map } from 'nanostores';
 import { logger, errorLogger } from './logger.mjs';
 import { loadBuffer } from './sampler.mjs';
@@ -608,6 +608,7 @@ export const superdough = async (value, t, hapDuration, cps = 0.5, cycle = 0.5)
     shapevol = getDefaultValue('shapevol'),
     distort,
     distortvol = getDefaultValue('distortvol'),
+    distorttype,
     pan,
     vowel,
     delay = getDefaultValue('delay'),
@@ -782,8 +783,7 @@ export const superdough = async (value, t, hapDuration, cps = 0.5, cycle = 0.5)
   // effects
   coarse !== undefined && chain.push(getWorklet(ac, 'coarse-processor', { coarse }));
   crush !== undefined && chain.push(getWorklet(ac, 'crush-processor', { crush }));
-  shape !== undefined && chain.push(getWorklet(ac, 'shape-processor', { shape, postgain: shapevol }));
-  distort !== undefined && chain.push(getWorklet(ac, 'distort-processor', { distort, postgain: distortvol }));
+  distort !== undefined && chain.push(getDistortion(distort, distortvol, distorttype));
 
   if (tremolosync != null) {
     tremolo = cps * tremolosync;

packages/superdough/worklets.mjs

@@ -7,6 +7,9 @@ import FFT from './fft.js';
 
 const clamp = (num, min, max) => Math.min(Math.max(num, min), max);
 const _mod = (n, m) => ((n % m) + m) % m;
+const ffloor = (x) => x | 0;
+const pv = (arr, n) => arr[n] ?? arr[0];
+const mix = (a, b, t) => (1 - t) * a + t * b;
 
 // Restrict phase to the range [0, maxPhase) via wrapping
 function wrapPhase(phase, maxPhase = 1) {
@@ -341,11 +344,85 @@ class LadderProcessor extends AudioWorkletProcessor {
 }
 registerProcessor('ladder-processor', LadderProcessor);
 
+// Saturation curves
+
+const __squash = (x) => x / (1 + x); // [0, inf) to [0, 1)
+
+const _scurve = (x, k) => ((1 + k) * x) / (1 + k * Math.abs(x));
+const _soft = (x, k) => Math.tanh(x * (1 + k));
+const _hard = (x, k) => clamp((1 + k) * x, -1, 1);
+const _sine = (x, k) => Math.sin(x * (1 + k));
+
+const _fold = (x, k) => {
+  let y = (1 + k) * x;
+  while (y > 1 || y < -1) {
+    y = y > 1 ? 2 - y : -2 - y;
+  }
+  return y;
+};
+
+const _sineFold = (x, k) => Math.sin((Math.PI / 2) * _fold(x, k));
+
+const _pow = (x, k) => {
+  const t = __squash(k);
+  const p = 1 / (1 + 0.5 * t); // tame k
+  return _soft(Math.sign(x) * Math.pow(Math.abs(x), p), 0.5 * k);
+};
+
+const _diode = (x, k, asym = false) => {
+  const g = 1 + k; // gain
+  const t = __squash(k);
+  const bias = 0.15 * t;
+  const pos = _soft(x + bias, k);
+  const neg = _soft(asym ? bias : -x + bias, k);
+  const y = pos - neg;
+  // We divide by the derivative at 0 so that the distortion is roughly
+  // the identity map near 0 => small values are preserved and undistorted
+  const sech = 1 / Math.cosh(g * bias);
+  const sech2 = sech * sech; // derivative of tanh is sech^2
+  const denom = Math.max(1e-8, (asym ? 1 : 2) * g * sech2); // g from chain rule; 2 if both pos/neg have x
+  return _soft(y / denom, k);
+};
+
+const _asym = (x, k) => _diode(x, k, true);
+
+const _cubic = (x, k) => {
+  const t = __squash(k);
+  const cubic = (x - (t / 3) * x * x * x) / (1 - t / 3); // normalized to go from (-1, 1)
+  return _soft(cubic, k);
+};
+
+export const saturationAlgos = {
+  scurve: _scurve,
+  soft: _soft,
+  hard: _hard,
+  sine: _sine,
+  fold: _fold,
+  sinefold: _sineFold,
+  pow: _pow,
+  cubic: _cubic,
+  diode: _diode,
+  asym: _asym,
+};
+const _algoNames = Object.freeze(Object.keys(saturationAlgos));
+
+const _getAlgorithm = (algo) => {
+  let algoName = typeof algo === 'string' ? algo : _algoNames[algo % _algoNames.length];
+  if (!_algoNames.includes(algoName)) {
+    algoName = _algoNames[0];
+    logger(`[superdough] Could not find waveshaping algorithm ${algo}.
+      Available options are ${_algoNames.join(', ')}.
+      Defaulting to ${algoName}.`);
+  }
+  return saturationAlgos[algoName];
+};
+
 class DistortProcessor extends AudioWorkletProcessor {
   static get parameterDescriptors() {
     return [
       { name: 'distort', defaultValue: 0 },
       { name: 'postgain', defaultValue: 1 },
+      { name: 'algorithm', defaultValue: 0, min: 0, max: _algoNames.length - 1 },
     ];
   }
 
@@ -363,13 +440,13 @@ class DistortProcessor extends AudioWorkletProcessor {
       return false;
     }
     this.started = hasInput;
-
-    const shape = Math.expm1(parameters.distort[0]);
-    const postgain = Math.max(0.001, Math.min(1, parameters.postgain[0]));
-
     for (let n = 0; n < blockSize; n++) {
-      for (let i = 0; i < input.length; i++) {
-        output[i][n] = (((1 + shape) * input[i][n]) / (1 + shape * Math.abs(input[i][n]))) * postgain;
+      const postgain = clamp(pv(parameters.postgain, n), 0.001, 1);
+      const shape = Math.expm1(pv(parameters.distort, n));
+      const algorithm = _getAlgorithm(pv(parameters.algorithm, n));
+      for (let ch = 0; ch < input.length; ch++) {
+        const x = input[ch][n];
+        output[ch][n] = postgain * algorithm(x, shape);
       }
     }
     return true;

website/src/repl/components/panel/SettingsTab.jsx

@@ -312,7 +312,7 @@ export function SettingsTab({ started }) {
             confirmDialog('Sure?').then((r) => {
               if (r) {
                 const { userPatterns } = settingsMap.get(); // keep current patterns
-                settingsMap.set({...defaultSettings, userPatterns});
+                settingsMap.set({ ...defaultSettings, userPatterns });
               }
             });
           }}