import {Note, Interval, Scale} from "../_snowpack/pkg/@tonaljs/tonal.js"; import {Pattern as _Pattern} from "../_snowpack/link/strudel.js"; import {mod, tokenizeNote} from "../_snowpack/link/util.js"; const Pattern = _Pattern; export function scaleTranspose(scale, offset, note) { let [tonic, scaleName] = Scale.tokenize(scale); let {notes} = Scale.get(`${tonic} ${scaleName}`); notes = notes.map((note2) => Note.get(note2).pc); offset = Number(offset); if (isNaN(offset)) { throw new Error(`scale offset "${offset}" not a number`); } const {pc: fromPc, oct = 3} = Note.get(note); const noteIndex = notes.indexOf(fromPc); if (noteIndex === -1) { throw new Error(`note "${note}" is not in scale "${scale}"`); } let i = noteIndex, o = oct, n = fromPc; const direction = Math.sign(offset); while (Math.abs(i - noteIndex) < Math.abs(offset)) { i += direction; const index = mod(i, notes.length); if (direction < 0 && n[0] === "C") { o += direction; } n = notes[index]; if (direction > 0 && n[0] === "C") { o += direction; } } return n + o; } Pattern.prototype._transpose = function(intervalOrSemitones) { return this._withEvent((event) => { const interval = !isNaN(Number(intervalOrSemitones)) ? Interval.fromSemitones(intervalOrSemitones) : String(intervalOrSemitones); if (typeof event.value === "number") { const semitones = typeof interval === "string" ? Interval.semitones(interval) || 0 : interval; return event.withValue(() => event.value + semitones); } return event.withValue(() => Note.simplify(Note.transpose(event.value, interval))); }); }; Pattern.prototype._scaleTranspose = function(offset) { return this._withEvent((event) => { if (!event.context.scale) { throw new Error("can only use scaleTranspose after .scale"); } if (typeof event.value !== "string") { throw new Error("can only use scaleTranspose with notes"); } return event.withValue(() => scaleTranspose(event.context.scale, Number(offset), event.value)); }); }; Pattern.prototype._scale = function(scale) { return this._withEvent((event) => { let note = event.value; const asNumber = Number(note); if (!isNaN(asNumber)) { let [tonic, scaleName] = Scale.tokenize(scale); const {pc, oct = 3} = Note.get(tonic); note = scaleTranspose(pc + " " + scaleName, asNumber, pc + oct); } return event.withValue(() => note).setContext({...event.context, scale}); }); }; Pattern.prototype.define("transpose", (a, pat) => pat.transpose(a), {composable: true, patternified: true}); Pattern.prototype.define("scale", (a, pat) => pat.scale(a), {composable: true, patternified: true}); Pattern.prototype.define("scaleTranspose", (a, pat) => pat.scaleTranspose(a), {composable: true, patternified: true});