Merge pull request #301 from tidalcycles/support-freq-in-sampler

add freq support to sampler

packages/core/test/util.test.mjs

@@ -10,6 +10,7 @@ import {
   tokenizeNote,
   toMidi,
   fromMidi,
+  freqToMidi,
   _mod,
   compose,
   getFrequency,
@@ -94,6 +95,12 @@ describe('fromMidi', () => {
     expect(fromMidi(57)).toEqual(220);
   });
 });
+describe('freqToMidi', () => {
+  it('should turn frequency into midi', () => {
+    expect(freqToMidi(440)).toEqual(69);
+    expect(freqToMidi(220)).toEqual(57);
+  });
+});
 describe('getFrequency', () => {
   const happify = (val, context = {}) => pure(val).firstCycle()[0].setContext(context);
   it('should turn note into frequency', () => {

packages/core/util.mjs

@@ -31,6 +31,30 @@ export const fromMidi = (n) => {
   return Math.pow(2, (n - 69) / 12) * 440;
 };
 
+export const freqToMidi = (freq) => {
+  return (12 * Math.log(freq / 440)) / Math.LN2 + 69;
+};
+
+export const valueToMidi = (value, fallbackValue) => {
+  if (typeof value !== 'object') {
+    throw new Error('valueToMidi: expected object value');
+  }
+  let { freq, note } = value;
+  if (typeof freq === 'number') {
+    return freqToMidi(freq);
+  }
+  if (typeof note === 'string') {
+    return toMidi(note);
+  }
+  if (typeof note === 'number') {
+    return note;
+  }
+  if (!fallbackValue) {
+    throw new Error('valueToMidi: expected freq or note to be set');
+  }
+  return fallbackValue;
+};
+
 /**
  * @deprecated does not appear to be referenced or invoked anywhere in the codebase
  */

packages/webaudio/sampler.mjs

@@ -1,4 +1,4 @@
-import { logger, toMidi } from '@strudel.cycles/core';
+import { logger, toMidi, valueToMidi } from '@strudel.cycles/core';
 import { getAudioContext } from './index.mjs';
 
 const bufferCache = {}; // string: Promise<ArrayBuffer>
@@ -20,9 +20,12 @@ function humanFileSize(bytes, si) {
   return bytes.toFixed(1) + ' ' + units[u];
 }
 
-export const getSampleBufferSource = async (s, n, note, speed) => {
+export const getSampleBufferSource = async (s, n, note, speed, freq) => {
   let transpose = 0;
-  let midi = typeof note === 'string' ? toMidi(note) : note || 36;
+  if (freq !== undefined && note !== undefined) {
+    logger('[sampler] hap has note and freq. ignoring note', 'warning');
+  }
+  let midi = valueToMidi({ freq, note }, 36);
   transpose = midi - 36; // C3 is middle C
 
   const ac = getAudioContext();

packages/webaudio/webaudio.mjs

@@ -288,10 +288,10 @@ export const webaudioOutput = async (hap, deadline, hapDuration) => {
 
     if (soundfont) {
       // is soundfont
-      bufferSource = await globalThis.getFontBufferSource(soundfont, note || n, ac);
+      bufferSource = await globalThis.getFontBufferSource(soundfont, note || n, ac, freq);
     } else {
       // is sample from loaded samples(..)
-      bufferSource = await getSampleBufferSource(s, n, note, speed);
+      bufferSource = await getSampleBufferSource(s, n, note, speed, freq);
     }
     // asny stuff above took too long?
     if (ac.currentTime > t) {

repl/src/prebake.mjs

@@ -1,4 +1,4 @@
-import { Pattern, toMidi } from '@strudel.cycles/core';
+import { Pattern, toMidi, valueToMidi } from '@strudel.cycles/core';
 import { samples } from '@strudel.cycles/webaudio';
 
 export async function prebake({ isMock = false, baseDir = '.' } = {}) {
@@ -25,9 +25,9 @@ Pattern.prototype.piano = function () {
     .s('piano')
     .release(0.1)
     .fmap((value) => {
-      const midi = typeof value.note === 'string' ? toMidi(value.note) : value.note;
+      const midi = valueToMidi(value);
       // pan by pitch
-      const pan = panwidth(Math.min(midi / maxPan, 1), 0.5);
+      const pan = panwidth(Math.min(Math.round(midi) / maxPan, 1), 0.5);
       return { ...value, pan: (value.pan || 1) * pan };
     });
 };