UGeoDB

Simple library to lookup city/country information based on Lat/Long.

Installation

1. Open Package Manager in Unity and Click on Plus Icon -> Add package from git URL, paste following link

   https://github.com/SrejonKhan/UGeoDB.git

   and click Add. Or, download latest .unitypackage and import it manually.

2. Open CopyStaticFiles window (Window/UGeoDB/CopyStaticFiles).

3. Select files and copy that are going to be used -

   

Static File Details

Name	Details
cities500.txt	Cities with a population > 500
cities1000.txt	Cities with a population > 1000
cities5000.txt	Cities with a population > 5000
cities15000.txt	Cities with a population > 15000
countryInfo.txt	All Countries

The following files are from GeoNames, under Creative Commons Attributions License.

Usage

Initialize

To initialize with default option (local / streaming assets) -

var option = new StreamingAssetsOption(CityDbType.cities500);
var geodb = new GeoDB(option);

In case, we can initialize with custom option. Any class that implements IResourceOption can be used as option. For example, if we want to read DB files from remote, firstly create a class that implements IResourceOption-

public class RemoteOption : IResourceOption
{
    public DbFile CountryDb { get; set; }
    public DbFile CityDb { get; set; }

    public RemoteOption()
    {
        CountryDb = new DbFile(path: "https://example.com/country_db.txt", isRemote: true);
        CityDb = new DbFile(path: "https://example.com/city_db.txt", isRemote: true);
    }
}

Now, initialize with that -

var remoteOption = new RemoteOption();
var geodb = new GeoDB(remoteOption);

OnLoad

Initialization takes time, as it read db files. So, if anything is called just after initialization, it may not work. It's better wait till it's loaded.

geoDb.OnLoad += () =>
{
    // ...
};

or, you can check if everything is loaded -

if(geoDb.IsLoaded)
{
    // ...
}

With Coroutine -

yield return new WaitUntil(() => geoDb.IsLoaded);

FindNearestCity

Given a GeoCoordinate, nearest city to the coordinate can be found easily -

var coord = new GeoCoordinate(23.4607, 91.1809);
var city = geoDb.FindNearestCity(coord);
Debug.Log(city.Name);

FindNearestCities

Given a GeoCoordinate, nearest cities in range (km/mi) to the coordinate can be found easily -

var coord = new GeoCoordinate(23.4607, 91.1809);
var cities = geoDb.FindNearestCities(coord, 50, GeoMath.DistanceUnit.Kilometers);
foreach(var city in cities)
{
    Debug.Log(city.Name);
}

GetCountry

To get the Country of a City (CityInfo) -

var coord = new GeoCoordinate(23.4607, 91.1809);
var city = geoDb.FindNearestCity(coord);
var country = geoDb.GetCountry(city);
Debug.Log(country.CountryName);

Calculate distance between two Geo Coordinates (Haversine Formula)

GeoCoordinate coord1 = new GeoCoordinate(23.8103, 90.4125);
GeoCoordinate coord2 = new GeoCoordinate(51.5072, -0.1276);
double distance = GeoMath.HaversineDistance(coord1, coord2, GeoMath.DistanceUnit.Kilometers);
Debug.Log(distance);