Added a class that calculates how a bounding box locks

Issue #29

Pirat/Other/NullCheck.cs

@@ -4,7 +4,7 @@ namespace Pirat.Other
 {
     public static class NullCheck
     {
-        public static void ThrowIfNull<T>(object argument)
+        public static void ThrowIfNull<T>(T argument)
         {
             if (argument == null) throw new ArgumentNullException($"Argument of type {typeof(T)} is null");
         }

Pirat/Services/Helper/BoundingBox.cs

@@ -0,0 +1,87 @@
+using Pirat.Other;
+
+namespace Pirat.Services.Helper
+{
+    public enum BoundingBoxType
+    {
+        Normal = 0,
+        WrappsSouthPole = 1,
+        WrappsNorthPole = 2,
+        WrappsHorizontalNorth = 4,
+        WrappsHorizontalSouth = 8,
+    }
+
+    public class BoundingBox
+    {
+        public BoundingBox(Location center, double radius)
+        {
+            this.Center = center;
+            this.Radius = radius;
+            SouthWestCorner = center.Move(-radius, -radius);
+            SouthEastCorner = center.Move(radius, -radius);
+            NorthWestCorner = center.Move(-radius, radius);
+            NorthEastCorner = center.Move(radius, radius);
+
+            this.Type = DetermineBoxType();
+        }
+
+        public Location Center { get; }
+        public double Radius { get; }
+        public Location NorthEastCorner { get; }
+
+        public Location NorthWestCorner { get; }
+
+        public Location SouthEastCorner { get; }
+
+        public Location SouthWestCorner { get; }
+        public BoundingBoxType Type { get; }
+
+        /// <summary>
+        /// Determines how a BoundingBox behaves at the edges.
+        /// </summary>
+        /// <returns>The type of the bounding box</returns>
+        private BoundingBoxType DetermineBoxType()
+        {
+            var wrappingSouth 
+                = SouthEastCorner.Longitude < SouthWestCorner.Longitude;
+            var wrappingNorth 
+                = NorthEastCorner.Longitude < NorthWestCorner.Longitude;
+
+            var distanceToNorth = Location.NorthPole.Distance(Center);
+            var distanceToSouth = Location.SouthPole.Distance(Center);
+
+            var wrappingNorthPole = distanceToNorth < Radius;
+            var wrappingSouthPole = distanceToSouth < Radius;
+
+            var type = BoundingBoxType.Normal;
+            if (wrappingSouth)
+            {
+                type |= BoundingBoxType.WrappsHorizontalSouth;
+            }
+
+            if (wrappingNorth)
+            {
+                type |= BoundingBoxType.WrappsHorizontalNorth;
+            }
+
+            if (wrappingNorthPole)
+            {
+                type |= BoundingBoxType.WrappsNorthPole;
+            }
+
+            if (wrappingSouthPole)
+            {
+                type |= BoundingBoxType.WrappsSouthPole;
+            }
+
+            return type;
+        }
+
+        public bool IsInRadius(Location other)
+        {
+            NullCheck.ThrowIfNull(other);
+
+            return this.Center.Distance(other) <= this.Radius;
+        }
+    }
+}