RegionMap.cs

using System;
using System.Net;
using System.Text.Json;

namespace EliteDangerousRegionMap
{
    public class SystemData
    {
        public string Name { get; set; }
        public long ID64 { get; set; }
        public double? X { get; set; }
        public double? Y { get; set; }
        public double? Z { get; set; }
        public Region Region { get; set; }
        public SystemBoxel Boxel { get; set; }
    }

    public class Region
    {
        public int Id { get; set; }
        public string Name { get; set; }
    }

    public class SystemBoxel
    {
        public double X { get; set; }
        public double Y { get; set; }
        public double Z { get; set; }
        public Region Region { get; set; }
    }

    public static partial class RegionMap
    {
        private class EDSMSystem
        {
            public string name { get; set; }
            public long id64 { get; set; }
            public EDSMSystemCoords coords { get; set; }
        }

        private class EDSMSystemCoords
        {
            public double x { get; set; }
            public double y { get; set; }
            public double z { get; set; }
        }

        private const double x0 = -49985;
        private const double y0 = -40985;
        private const double z0 = -24105;

        public static Region FindRegion(double x, double y, double z)
        {
            var px = (int)((x - x0) * 83 / 4096);
            var pz = (int)((z - z0) * 83 / 4096);

            if (px < 0 || pz < 0 || pz >= RegionMapLines.Length)
            {
                return default;
            }
            else
            {
                var row = RegionMapLines[pz];
                var rx = 0;
                var pv = 0;

                foreach (var (rl, rv) in row)
                {
                    if (px < rx + rl)
                    {
                        pv = rv;
                        break;
                    }
                    else
                    {
                        rx += rl;
                    }
                }

                if (pv == 0)
                {
                    return null;
                }
                else
                {
                    return new Region { Id = pv, Name = RegionNames[pv] };
                }
            }
        }

        public static SystemBoxel FindRegionForBoxel(long id64)
        {
            int masscode = (int)(id64 & 7);
            double x = (((id64 >> (30 - masscode * 2)) & (0x3FFF >> masscode)) << masscode) * 10 + x0;
            double y = (((id64 >> (17 - masscode)) & (0x1FFF >> masscode)) << masscode) * 10 + y0;
            double z = (((id64 >> 3) & (0x3FFF >> masscode)) << masscode) * 10 + z0;

            return new SystemBoxel
            {
                X = x,
                Y = y,
                Z = z,
                Region = FindRegion(x, y, z)
            };
        }

        public static SystemData[] FindRegionsForSystems(string sysname)
        {
            var url = $"https://www.edsm.net/api-v1/systems?systemName={Uri.EscapeDataString(sysname)}&coords=1&showId=1";
            var client = new WebClient();
            var jsonstr = client.DownloadString(url);
            var systems = JsonSerializer.Deserialize<EDSMSystem[]>(jsonstr);
            var sysregions = new SystemData[systems.Length];

            for (int i = 0; i < systems.Length; i++)
            {
                var system = systems[i];

                var sysdata = sysregions[i] = new SystemData
                {
                    Name = system.name,
                    ID64 = system.id64
                };

                if (system.coords != null)
                {
                    double x = system.coords.x;
                    double y = system.coords.y;
                    double z = system.coords.z;
                    sysdata.X = x;
                    sysdata.Y = y;
                    sysdata.Z = z;

                    sysdata.Region = FindRegion(x, y, z);
                }

                if (system.id64 != 0)
                {
                    sysdata.Boxel = FindRegionForBoxel((long)system.id64);
                }
            }

            return sysregions;
        }

        private static void Main(string[] args)
        {
            if (args.Length == 0)
            {
                var exe = System.Reflection.Assembly.GetExecutingAssembly().Location;
                Console.WriteLine($"Usage: {exe} \"System 1\" [...]");
                return;
            }

            foreach (var name in args)
            {
                foreach (var sysdata in FindRegionsForSystems(name))
                {
                    if (sysdata.X != null)
                    {
                        var x = sysdata.X;
                        var y = sysdata.Y;
                        var z = sysdata.Z;

                        if (sysdata.Region != null)
                        {
                            Console.WriteLine($"System {sysdata.Name} at ({x},{y},{z}) is in region {sysdata.Region.Id} ({sysdata.Region.Name})");
                        }
                        else
                        {
                            Console.WriteLine($"System {sysdata.Name} at ({x},{y},{z}) is outside the region map");
                        }
                    }

                    if (sysdata.Boxel != null && sysdata.Boxel.Region.Id != sysdata.Region?.Id)
                    {

                        var boxel = sysdata.Boxel;
                        var x = boxel.X;
                        var y = boxel.Y;
                        var z = boxel.Z;

                        if (boxel.Region != null)
                        {
                            Console.WriteLine($"Boxel of system {sysdata.Name} at ({x},{y},{z}) is in region {boxel.Region.Id} ({boxel.Region.Name})");
                        }
                        else
                        {
                            Console.WriteLine($"Boxel of system {sysdata.Name} at ({x},{y},{z}) is outside the region map");
                        }
                    }
                }
            }
        }
    }
}