traque/traque-back/map_utils.js

export function getDistanceFromLatLon({ lat: lat1, lng: lon1 }, { lat: lat2, lng: lon2 }) {
    var R = 6371; // Radius of the earth in km
    var dLat = deg2rad(lat2 - lat1);  // deg2rad below
    var dLon = deg2rad(lon2 - lon1);
    var a =
        Math.sin(dLat / 2) * Math.sin(dLat / 2) +
        Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) *
        Math.sin(dLon / 2) * Math.sin(dLon / 2)
        ;
    var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
    var d = R * c; // Distance in km
    return d * 1000;
}

function deg2rad(deg) {
    return deg * (Math.PI / 180)
}

export function isInCircle(position, center, radius) {
    return getDistanceFromLatLon(position, center) < radius;
}