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voicing modes: below, under, above

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This commit is contained in:
Felix Roos 2023-07-12 23:32:27 +02:00
parent 58fc786462
commit 4cf3655c08
3 changed files with 56 additions and 35 deletions
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40
packages/tonal/tonleiter.mjs
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@ -1,4 +1,4 @@
import { isNote, isNoteWithOctave, _mod } from '@strudel.cycles/core';
import { isNote, isNoteWithOctave, _mod, noteToMidi } from '@strudel.cycles/core';
import { Interval } from '@tonaljs/tonal';
// https://codesandbox.io/s/stateless-voicings-g2tmz0?file=/src/lib.js:0-2515
@ -30,10 +30,6 @@ export function tokenizeChord(chord) {
export const note2pc = (note) => note.slice(0, -1);
export const note2oct = (note) => Number(note.slice(-1));
export const note2midi = (note) => {
const [pc, oct] = [note2pc(note), note2oct(note)];
return pc2chroma(pc) + oct * 12 + 12;
};
export const note2chroma = (note) => {
return pc2chroma(note2pc(note));
};
@ -42,13 +38,13 @@ export const note2chroma = (note) => {
export const midi2chroma = (midi) => midi % 12;
// TODO: test and use in voicing function
export const pitch2chroma = (x) => {
export const pitch2chroma = (x, defaultOctave) => {
if (isNoteWithOctave(x)) {
return note2chroma(x);
}
if (isNote(x)) {
//pc
return pc2chroma(x);
return pc2chroma(x, defaultOctave);
}
if (typeof x === 'number') {
// expect midi
@ -69,7 +65,7 @@ export const x2midi = (x) => {
return x;
}
if (typeof x === 'string') {
return note2midi(x);
return noteToMidi(x);
}
};
@ -81,17 +77,24 @@ export const midi2note = (midi, sharp = false) => {
};
export function scaleStep(notes, offset) {
notes = notes.map((note) => (typeof note === 'string' ? note2midi(note) : note));
notes = notes.map((note) => (typeof note === 'string' ? noteToMidi(note) : note));
const octOffset = Math.floor(offset / notes.length) * 12;
offset = _mod(offset, 12);
return notes[offset % notes.length] + octOffset;
}
export function renderVoicing({ chord, anchor, dictionary, offset = 0, n, mode }) {
anchor = anchor?.note || anchor || 'c5';
// different ways to resolve the note to compare the anchor to (see renderVoicing)
let modeTarget = {
below: (v) => v.slice(-1)[0],
under: (v) => v.slice(-1)[0],
above: (v) => v[0],
};
export function renderVoicing({ chord, dictionary, offset = 0, n, mode = 'above', anchor = 'c4' }) {
const [root, symbol] = tokenizeChord(chord);
const anchorChroma = pitch2chroma(anchor);
const rootChroma = pc2chroma(root);
anchor = anchor?.note || anchor;
const anchorChroma = pitch2chroma(anchor);
const voicings = dictionary[symbol].map((voicing) =>
(typeof voicing === 'string' ? voicing.split(' ') : voicing).map(step2semitones),
);
@ -99,7 +102,8 @@ export function renderVoicing({ chord, anchor, dictionary, offset = 0, n, mode }
let minDistance, bestIndex;
// calculate distances up from voicing top notes
let chromaDiffs = voicings.map((v, i) => {
const diff = _mod(anchorChroma - v.slice(-1)[0] - rootChroma, 12);
const targetStep = modeTarget[mode](v);
const diff = _mod(anchorChroma - targetStep - rootChroma, 12);
if (minDistance === undefined || diff < minDistance) {
minDistance = diff;
bestIndex = i;
@ -110,16 +114,16 @@ export function renderVoicing({ chord, anchor, dictionary, offset = 0, n, mode }
const octDiff = Math.ceil(offset / voicings.length) * 12;
const indexWithOffset = _mod(bestIndex + offset, voicings.length);
const voicing = voicings[indexWithOffset];
const maxMidi = note2midi(anchor);
const topMidi = maxMidi - chromaDiffs[indexWithOffset] + octDiff;
const targetStep = modeTarget[mode](voicing);
const anchorMidi = noteToMidi(anchor, 4) - chromaDiffs[indexWithOffset] + octDiff;
const voicingMidi = voicing.map((v) => topMidi - voicing[voicing.length - 1] + v);
const voicingMidi = voicing.map((v) => anchorMidi - targetStep + v);
let notes = voicingMidi.map((n) => midi2note(n));
if (n !== undefined) {
return [scaleStep(notes, n)];
}
if (mode === 'below') {
notes = notes.filter((n) => x2midi(n) !== note2midi(anchor));
if (mode === 'under') {
notes = notes.filter((n) => x2midi(n) !== noteToMidi(anchor));
}
return notes;
}