react-orchestra
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A toolbox to build interactive and smart instruments on the web and mobile.
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<h1 class="page-title">Source: helpers/updateTempo.js</h1>
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<pre class="prettyprint source linenums"><code>/* mod */
import update from 'immutability-helper';
import MidiIO from '../../MidiIO';
import Note from '../Note';
/**
* reorder a set of notes such that it starts with the firstNote
* @function
* @name updateTempo
* @param {object} tracksAndMeta from getTracksAndMetaFromParsedMidi getTracksAndMetaFromUrl
* @param {array} notes
* @example
* const newBPM = 60;
* const trackIndex = 1;
* const tracksAndMeta = await getTracksAndMetaFromUrl(url);
* const updatedTracksAndMeta = updateTempo(tracksAndMeta, newBPM, trackIndex);
* updateTempo('A' , ['C', 'B', 'A']); // returns ['A', 'B', 'C']
* reOrderNotes('B'); // returns ['B', 'C', 'D', 'E', 'F', 'G', 'A']
* @return {object} tracksAndMeta
*/
const updateTempo = (tracksAndMeta, BPM, trackIndex = -1) => {
const trackMeta = tracksAndMeta.meta;
// const trackNotes = tracksAndMeta.notes[0];
const newMSPerBeat = MidiIO.bpmToMSPerBeat(
BPM,
trackMeta.timeSignatureNumerator,
trackMeta.timeSignatureDenominator
);
const newMSPerTick = MidiIO.getMillisecondsPerTick(newMSPerBeat / 1000, trackMeta.ticksPerBeat);
const updatedMeta = update(trackMeta, {
millisecondsPerTick: {
$set: newMSPerTick,
},
BPM: {
$set: BPM,
},
});
let previousEndTime = 0;
const updatedTracks = tracksAndMeta.tracks.map((track, i) => {
if (trackIndex !== -1 && i !== trackIndex) {
return track;
}
const updatedTrack = track.map((note, j) => {
const {
noteNumber,
noteName,
startTimeInMS,
durationInMS,
endTimeInMS,
noteInstrumentName,
deltaTime,
msPerTick,
} = MidiIO.noteOffEventToNote(
{
deltaTime: note.payload.deltaTime,
noteNumber: note.payload.noteNumber,
},
note.payload.instrumentName,
previousEndTime,
newMSPerTick
);
previousEndTime = endTimeInMS;
const updatedNote = new Note({
noteNumber,
noteName,
startTimeInMS,
durationInMS,
endTimeInMS,
instrumentName: noteInstrumentName,
deltaTime,
msPerTick: newMSPerTick,
});
return updatedNote;
});
return updatedTrack;
});
return { meta: updatedMeta, tracks: updatedTracks };
};
export default updateTempo;
</code></pre>
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<h2><a href="index.html">Home</a></h2><h3>Classes</h3><ul><li><a href="Instrument.html">Instrument</a></li><li><a href="Note.html">Note</a></li></ul><h3>Global</h3><ul><li><a href="global.html#addOctaveToNoteName">addOctaveToNoteName</a></li><li><a href="global.html#getInterval">getInterval</a></li><li><a href="global.html#getIntervalPermutationsFromNoteNames">getIntervalPermutationsFromNoteNames</a></li><li><a href="global.html#getJSONFromMidiURL">getJSONFromMidiURL</a></li><li><a href="global.html#getNoteNamesFromChordName">getNoteNamesFromChordName</a></li><li><a href="global.html#getNoteNamesFromIntervals">getNoteNamesFromIntervals</a></li><li><a href="global.html#getScaleNotes">getScaleNotes</a></li><li><a href="global.html#getScalesFromNoteNames">getScalesFromNoteNames</a></li><li><a href="global.html#getTracksAndMetaFromParsedMidi">getTracksAndMetaFromParsedMidi</a></li><li><a href="global.html#getTracksAndMetaFromUrl">getTracksAndMetaFromUrl</a></li><li><a href="global.html#getUniqueNoteNames">getUniqueNoteNames</a></li><li><a href="global.html#getUniqueNoteNamesNoOctave">getUniqueNoteNamesNoOctave</a></li><li><a href="global.html#isInHigherOctave">isInHigherOctave</a></li><li><a href="global.html#removeOctaveFromNoteName">removeOctaveFromNoteName</a></li><li><a href="global.html#reOrderNotes">reOrderNotes</a></li><li><a href="global.html#updateTempo">updateTempo</a></li></ul>
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Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.4.3</a> on Sun Nov 20 2016 16:43:09 GMT+0200 (EET)
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