begin am feature

packages/core/controls.mjs

@@ -134,7 +134,8 @@ const generic_params = [
    *
    */
   [['fmi', 'fmh'], 'fm'],
-
+  ['amh'],
+  ['ami'],
   /**
    * Select the sound bank to use. To be used together with `s`. The bank name (+ "_") will be prepended to the value of `s`.
    *

packages/superdough/helpers.mjs

@@ -68,3 +68,17 @@ export const getFilter = (type, frequency, Q) => {
   filter.Q.value = Q;
   return filter;
 };
+
+export const getAM = (freq, harmonicityRatio, amount, wave = 'sine') => {
+  const carrfreq = freq;
+  const modfreq = carrfreq * harmonicityRatio;
+  const { node: modulator, stop } = mod(modfreq, amount, wave);
+  const g = gainNode(1);
+  modulator.connect(g.gain);
+  return g;/* 
+  const c = 1 / 1 ** amount;
+  console.log('c', c);
+  const compensate = gainNode(1/amount);
+  g.connect(compensate);
+  return compensate; */
+};

packages/superdough/superdough.mjs

@@ -7,7 +7,7 @@ This program is free software: you can redistribute it and/or modify it under th
 import './feedbackdelay.mjs';
 import './reverb.mjs';
 import './vowel.mjs';
-import { clamp } from './util.mjs';
+import { clamp, getFrequency } from './util.mjs';
 import workletsUrl from './worklets.mjs?url';
 import { getFilter, gainNode } from './helpers.mjs';
 import { map } from 'nanostores';
@@ -167,6 +167,8 @@ export const superdough = async (value, deadline, hapDuration) => {
     room,
     size = 2,
     velocity = 1,
+    amh, // amplitude modulation harmonicity
+    ami = 4, // amplitude modulation index
   } = value;
   gain *= velocity; // legacy fix for velocity
   let toDisconnect = []; // audio nodes that will be disconnected when the source has ended
@@ -205,6 +207,7 @@ export const superdough = async (value, deadline, hapDuration) => {
   // gain stage
   chain.push(gainNode(gain));
 
+  amh !== undefined && chain.push(getAM(getFrequency(value), amh, ami));
   // filters
   cutoff !== undefined && chain.push(getFilter('lowpass', cutoff, resonance));
   hcutoff !== undefined && chain.push(getFilter('highpass', hcutoff, hresonance));

packages/superdough/synth.mjs

@@ -2,7 +2,7 @@ import { midiToFreq, noteToMidi } from './util.mjs';
 import { registerSound, getAudioContext } from './superdough.mjs';
 import { getOscillator, gainNode, getEnvelope } from './helpers.mjs';
 
-const mod = (freq, range = 1, type = 'sine') => {
+export const mod = (freq, range = 1, type = 'sine') => {
   const ctx = getAudioContext();
   const osc = ctx.createOscillator();
   osc.type = type;

packages/superdough/util.mjs

@@ -51,3 +51,21 @@ export const valueToMidi = (value, fallbackValue) => {
   }
   return fallbackValue;
 };
+
+export const getFrequency = (value) => {
+  // if value is number => interpret as midi number as long as its not marked as frequency
+  if (typeof value === 'object') {
+    if (value.freq) {
+      return value.freq;
+    }
+    return getFreq(value.note || value.n || value.value || 36);
+  }
+  if (typeof value === 'number' && context.type !== 'frequency') {
+    value = midiToFreq(hap.value);
+  } else if (typeof value === 'string' && isNote(value)) {
+    value = midiToFreq(noteToMidi(hap.value));
+  } else if (typeof value !== 'number') {
+    throw new Error('not a note or frequency: ' + value);
+  }
+  return value;
+};