react-orchestra
Version:
A toolbox to build interactive and smart instruments on the web and mobile.
55 lines (53 loc) • 1.93 kB
JavaScript
/* mod */
import SCALES from '../constants/SCALES';
import getUniqueNoteNamesNoOctave from './getUniqueNoteNamesNoOctave';
import getIntervalPermutationsFromNoteNames from './getIntervalPermutationsFromNoteNames';
/**
* getScalesFromNoteNames - Get all scales matched with the given notes
*
* @param {array} noteNames noteNames with octave
* @returns {array} Array of note names with octave
* [{firstNoteName: string, intervals: number, guessedScales: array}]
* @example
* getScalesFromNoteNames(['A3', 'B3', 'C3']);
* // [
* // {
* // firstNoteName: 'A',
* // intervals: [0, 9, 10],
* // guessedScales: ['dorian', 'mixolydian', 'acoustic', 'algerian', 'majorBlues']
* // },
* // {
* // firstNoteName: 'B',
* // intervals: [0, 2, 11],
* // guessedScales: ['ionian', 'lydian', 'harmonicMinor', 'melodicMinorAsc']
* // },
* // {
* // firstNoteName: 'C',
* // intervals: [0, 1, 3],
* // guessedScales: ['phrygian', 'locrian', 'altered']
* // },
* // ]
*/
var getScalesFromNoteNames = function getScalesFromNoteNames(noteNames) {
var uniqueNoteNames = getUniqueNoteNamesNoOctave(noteNames);
var sequencePermutations = getIntervalPermutationsFromNoteNames(uniqueNoteNames);
Object.keys(SCALES).forEach(function (scaleName) {
var scaleSequence = SCALES[scaleName].sequence;
if (scaleName === 'chromatic') {
return;
}
sequencePermutations.forEach(function (sequencePermutation, i) {
var isInScaleSequence = sequencePermutation.intervals.reduce(function (prev, current) {
if (prev === false) {
return false;
}
return scaleSequence.indexOf(current) !== -1;
}, true);
if (isInScaleSequence) {
sequencePermutations[i].guessedScales.push(scaleName);
}
});
});
return sequencePermutations;
};
export default getScalesFromNoteNames;