mobility-toolbox-js/maplibre/utils/getMercatorResolution.js

Toolbox for JavaScript applications in the domains of mobility and logistics.

import { getWidth, getHeight } from 'ol/extent';
import { fromLonLat } from 'ol/proj';
/**
 * Get the current resolution of a Maplibre map.
 * @param {maplibregl.Map} map A map object.
 */
const getMercatorResolution = (map) => {
    const bounds = map.getBounds().toArray();
    const a = fromLonLat(bounds[0]);
    const b = fromLonLat(bounds[1]);
    const extent = [...a, ...b];
    const { width, height } = map.getCanvas();
    const xResolution = getWidth(extent) / width;
    const yResolution = getHeight(extent) / height;
    return Math.max(xResolution, yResolution);
};
export default getMercatorResolution;