s2maps-gpu/dist/util/hash.js

S2 Maps GPU - An open source, high-performance, and GPU-accelerated map engine for rendering large-scale, interactive maps.

/**
 * Sets the hash in the location bar given the current view
 * @param view - The current camera view
 */
export function setHash(view) {
    const { bearing, pitch } = view;
    let { lon, lat, zoom } = view;
    zoom = Math.round(zoom * 100) / 100;
    // derived from equation: 512px * 2^z / 360 / 10^d < 0.5px
    const precision = Math.ceil((zoom * Math.LN2 + Math.log(512 / 360 / 0.5)) / Math.LN10);
    const m = Math.pow(10, precision);
    lon = Math.round(lon * m) / m;
    lat = Math.round(lat * m) / m;
    let hash = `#${zoom}/${lon}/${lat}`;
    if (bearing !== 0)
        hash += `/${Math.round(bearing * 10) / 10}`;
    if (pitch !== 0)
        hash += `/${Math.round(pitch)}`;
    // set hash on the location bar
    const location = window.location.href.replace(/(#.+)?$/, hash);
    window.history.replaceState(window.history.state, '', location);
}
/** @returns The current view converted from the hash */
export function parseHash() {
    const view = {};
    const [, hash] = window.location.href.split('#');
    // corner case: no hash
    if (hash === undefined)
        return view;
    // parse hash
    const [zoom, lon, lat, bearing, pitch] = hash.split('/');
    view.zoom = parseFloat(zoom);
    view.lon = parseFloat(lon);
    view.lat = parseFloat(lat);
    if (bearing !== undefined)
        view.bearing = parseFloat(bearing);
    if (pitch !== undefined)
        view.pitch = parseFloat(pitch);
    return view;
}