@stringsync/vexml/dist/esm/rendering/time.js

MusicXML to Vexflow

import * as vexflow from 'vexflow';
import { Rect } from '../spatial';
import { Fraction } from '../util';
const ADDITIONAL_COMPLEX_TIME_SIGNATURE_COMPONENT_WIDTH = 18;
export class Time {
    config;
    log;
    document;
    key;
    constructor(config, log, document, key) {
        this.config = config;
        this.log = log;
        this.document = document;
        this.key = key;
    }
    render() {
        const timeSpecs = this.getTimeSpecs();
        const vexflowTimeSignatures = timeSpecs.map((t) => new vexflow.TimeSignature(t));
        const padding = ADDITIONAL_COMPLEX_TIME_SIGNATURE_COMPONENT_WIDTH * (timeSpecs.length - 1);
        const width = vexflowTimeSignatures.reduce((sum, t) => sum + t.getWidth(), padding);
        return {
            type: 'time',
            rect: Rect.empty(), // placeholder
            key: this.key,
            vexflowTimeSignatures,
            width,
        };
    }
    getTimeSpecs() {
        const time = this.document.getStave(this.key).signature.time;
        const components = this.toFractions(time.components);
        switch (time.symbol) {
            case 'common':
                return ['C'];
            case 'cut':
                return ['C|'];
            case 'single-number':
                const sum = Fraction.sum(...components).simplify();
                return [this.toSimpleTimeSpecs(sum)];
            case 'hidden':
                return [];
        }
        if (components.length > 1) {
            return this.toComplexTimeSpecs(components);
        }
        return [this.toSimpleTimeSpecs(components[0])];
    }
    toSimpleTimeSpecs(component) {
        return `${component.numerator}/${component.denominator}`;
    }
    toComplexTimeSpecs(components) {
        const denominators = new Array();
        const memo = {};
        for (const component of components) {
            const numerator = component.numerator;
            const denominator = component.denominator;
            if (typeof memo[denominator] === 'undefined') {
                denominators.push(denominator);
            }
            memo[denominator] ??= [];
            memo[denominator].push(numerator);
        }
        const result = new Array();
        for (let index = 0; index < denominators.length; index++) {
            const denominator = denominators[index];
            const isLast = index === denominators.length - 1;
            result.push(`${memo[denominator].join('+')}/${denominator}`);
            if (!isLast) {
                result.push('+');
            }
        }
        return result;
    }
    toFractions(components) {
        return components.map((component) => new Fraction(component.numerator, component.denominator));
    }
}