Add packages/edo for Equal Division of the Octave scales

packages/edo/edo.mjs

@@ -0,0 +1,75 @@
+/*
+edo.mjs - Equal division of the octave (EDO) scale functions for strudel
+Copyright (C) 2025 Rob McKinnon and Strudel contributors - see <https://codeberg.org/uzu/strudel/src/branch/main/packages/edo/edo.mjs>
+This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more details. You should have received a copy of the GNU Affero General Public License along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+import { register, pure, noteToMidi, isNote, tokenizeNote } from '@strudel/core';
+import { EdoScale } from './edoscale.mjs';
+import { Intervals } from './intervals.mjs';
+import { Pitches } from './pitches.mjs';
+
+const pitchesCache = new Map();
+
+export const edoScale = register(
+  'edoScale',
+  function (scaleDefinition, pat) {
+    // console.log(scaleDefinition);
+
+    // if (Array.isArray(scale)) {
+    const key = scaleDefinition.flat().join(':');
+    // }
+    // console.log(scaleDefinition);
+    let pitches;
+    if (pitchesCache.has(key)) {
+      pitches = pitchesCache.get(key);
+    } else {
+      // console.log({ key });
+      const [base_note, sequence, large, small] = scaleDefinition;
+      const root_octave = tokenizeNote(base_note)[2] || 3;
+      // console.log({ root_octave });
+      const scale = new EdoScale(large, small, sequence);
+      const intervals = new Intervals(scale);
+      // console.log({ intervals });
+      pitches = new Pitches(scale, intervals, 440, noteToMidi(base_note), root_octave);
+      pitchesCache.set(key, pitches);
+      // console.log({ base_note: noteToMidi(base_note) });
+      // console.log({ sequence });
+      // console.log({ edivisions: scale.edivisions });
+      // console.log({ intervals });
+      // console.log({ pat });
+      // console.log({ pitches: pitches });
+    }
+    return pat
+      .fmap((value) => {
+        const isObject = typeof value === 'object';
+        const n = isObject ? value.n : value;
+        if (isObject) {
+          delete value.n; // remove n so it won't cause trouble
+        }
+        if (isNote(n)) {
+          // legacy..
+          return pure(n);
+        }
+        const deg = (typeof n === 'string' ? parseInt(n, 10) : n) + 1;
+
+        const [oct, degree] = pitches.octdeg(deg);
+        const freq = pitches.octdegfreq(oct, degree);
+        const note = pitches.octdegmidi(oct, degree);
+        const edo = pitches.scale.edivisions;
+        const root = pitches.base_freq;
+        const degreeIndexes = pitches.scale.divisions;
+        const intLabels = pitches.intervals.intLabels;
+        // const color = 'red';
+        value = pure(isObject ? { ...value, degree, degreeIndexes, intLabels, root, freq, edo } : note);
+        // value = pure(isObject ? { ...value, key } : note);
+        // value = pure(isObject ? { ...value, edo } : note);
+        // console.log({ value });
+        return value;
+      })
+      .outerJoin()
+      .withHap((hap) => hap.setContext({ ...hap.context, scaleDefinition }));
+  },
+  true,
+  true, // preserve tactus
+);