maplibre-gl/src/tile/tile_id_to_lng_lat_bounds.ts

BSD licensed community fork of mapbox-gl, a WebGL interactive maps library

import {latFromMercatorY, lngFromMercatorX} from '../geo/mercator_coordinate.ts';
import {LngLatBounds} from '../geo/lng_lat_bounds.ts';
import type {CanonicalTileID} from './tile_id.ts';

export function tileIdToLngLatBounds(
    {x,y,z}: CanonicalTileID,
    buffer: number = 0,
): LngLatBounds {
    const lngMin = lngFromMercatorX((x - buffer) / Math.pow(2, z));
    const latMin = latFromMercatorY((y + 1 + buffer) / Math.pow(2, z));

    const lngMax = lngFromMercatorX((x + 1 + buffer) / Math.pow(2, z));
    const latMax = latFromMercatorY((y - buffer) / Math.pow(2, z));

    return new LngLatBounds([lngMin, latMin], [lngMax, latMax]);
}