2022-11-24 15:30:11 +01:00

69 lines
2.7 KiB
JavaScript

/*
voicings.mjs - <short description TODO>
Copyright (C) 2022 Strudel contributors - see <https://github.com/tidalcycles/strudel/blob/main/packages/tonal/voicings.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 { Pattern as _Pattern, stack, Hap, reify } from '@strudel.cycles/core';
import _voicings from 'chord-voicings';
const { dictionaryVoicing, minTopNoteDiff, lefthand } = _voicings.default || _voicings; // parcel module resolution fuckup
const getVoicing = (chord, lastVoicing, range = ['F3', 'A4']) =>
dictionaryVoicing({
chord,
dictionary: lefthand,
range,
picker: minTopNoteDiff,
lastVoicing,
});
const Pattern = _Pattern;
Pattern.prototype.fmapNested = function (func) {
return new Pattern((span) =>
this.query(span)
.map((event) =>
reify(func(event))
.query(span)
.map((hap) => new Hap(event.whole, event.part, hap.value, hap.context)),
)
.flat(),
);
};
/**
* Turns chord symbols into voicings, using the smoothest voice leading possible.
* Uses [chord-voicings package](https://github.com/felixroos/chord-voicings#chord-voicings).
*
* @name voicings
* @memberof Pattern
* @param {range} range note range for possible voicings (optional, defaults to `['F3', 'A4']`)
* @returns Pattern
* @example
* stack("<C^7 A7 Dm7 G7>".voicings(), "<C3 A2 D3 G2>").note()
*/
Pattern.prototype.voicings = function (range) {
let lastVoicing;
if (!range?.length) {
// allows to pass empty array, if too lazy to specify range
range = ['F3', 'A4'];
}
return this.fmapNested((event) => {
lastVoicing = getVoicing(event.value, lastVoicing, range);
return stack(...lastVoicing).withContext(() => ({
locations: event.context.locations || [],
}));
});
};
Pattern.prototype._rootNotes = function (octave = 2) {
return this.fmap((value) => {
const root = value.match(/^([a-gA-G][b#]?).*$/)[1];
return root + octave;
});
};
Pattern.prototype.define('voicings', (range, pat) => pat.voicings(range), { composable: true });
Pattern.prototype.define('rootNotes', (oct, pat) => pat.rootNotes(oct), { composable: true, patternified: true });