Added enum Hemisphere

MapControl/Shared/MapProjectionFactory.cs

@@ -32,6 +32,10 @@ namespace MapControl
                     projection = new UpsSouthProjection();
                     break;
 
+                case "AUTO-UTM":                   
+                    projection = new Wgs84AutoUtmProjection(null); // client-side auto zone
+                    break;
+
                 case Wgs84AutoUtmProjection.DefaultCrsId:
                     projection = new Wgs84AutoUtmProjection();
                     break;
@@ -76,8 +80,8 @@ namespace MapControl
             var code when code >= Etrs89UtmProjection.FirstZoneEpsgCode && code <= Etrs89UtmProjection.LastZoneEpsgCode => new Etrs89UtmProjection(epsgCode % 100),
             var code when code >= Nad27UtmProjection.FirstZoneEpsgCode && code <= Nad27UtmProjection.LastZoneEpsgCode => new Nad27UtmProjection(epsgCode % 100),
             var code when code >= Nad83UtmProjection.FirstZoneEpsgCode && code <= Nad83UtmProjection.LastZoneEpsgCode => new Nad83UtmProjection(epsgCode % 100),
-            var code when code >= Wgs84UtmProjection.FirstZoneNorthEpsgCode && code <= Wgs84UtmProjection.LastZoneNorthEpsgCode => new Wgs84UtmProjection(epsgCode % 100, true),
+            var code when code >= Wgs84UtmProjection.FirstZoneNorthEpsgCode && code <= Wgs84UtmProjection.LastZoneNorthEpsgCode => new Wgs84UtmProjection(epsgCode % 100, Hemisphere.North),
-            var code when code >= Wgs84UtmProjection.FirstZoneSouthEpsgCode && code <= Wgs84UtmProjection.LastZoneSouthEpsgCode => new Wgs84UtmProjection(epsgCode % 100, false),
+            var code when code >= Wgs84UtmProjection.FirstZoneSouthEpsgCode && code <= Wgs84UtmProjection.LastZoneSouthEpsgCode => new Wgs84UtmProjection(epsgCode % 100, Hemisphere.South),
             _ => null
         };
     }

MapControl/Shared/PolarStereographicProjection.cs

@@ -24,13 +24,13 @@ namespace MapControl
         public double ScaleFactor { get; set; } = 0.994;
         public double FalseEasting { get; set; } = 2e6;
         public double FalseNorthing { get; set; } = 2e6;
-        public bool IsNorth { get; set; }
+        public Hemisphere Hemisphere { get; set; }
 
         public override Point RelativeScale(double latitude, double longitude)
         {
             latitude *= Math.PI / 180d;
 
-            if (!IsNorth)
+            if (Hemisphere == Hemisphere.South)
             {
                 latitude = -latitude;
             }
@@ -54,7 +54,7 @@ namespace MapControl
             latitude *= Math.PI / 180d;
             longitude *= Math.PI / 180d;
 
-            if (!IsNorth)
+            if (Hemisphere == Hemisphere.South)
             {
                 latitude = -latitude;
                 longitude = -longitude;
@@ -71,7 +71,7 @@ namespace MapControl
             var x = r * Math.Sin(longitude); // p.161 (21-30)
             var y = -r * Math.Cos(longitude); // p.161 (21-31)
 
-            if (!IsNorth)
+            if (Hemisphere == Hemisphere.South)
             {
                 x = -x;
                 y = -y;
@@ -85,7 +85,7 @@ namespace MapControl
             x -= FalseEasting;
             y -= FalseNorthing;
 
-            if (!IsNorth)
+            if (Hemisphere == Hemisphere.South)
             {
                 x = -x;
                 y = -y;
@@ -99,7 +99,7 @@ namespace MapControl
             var lat = WorldMercatorProjection.ApproximateLatitude(e, t); // p.162 (3-5)
             var lon = Math.Atan2(x, -y); // p.162 (20-16)
 
-            if (!IsNorth)
+            if (Hemisphere == Hemisphere.South)
             {
                 lat = -lat;
                 lon = -lon;
@@ -125,7 +125,7 @@ namespace MapControl
         public UpsNorthProjection(string crsId)
         {
             CrsId = crsId;
-            IsNorth = true;
+            Hemisphere = Hemisphere.North;
         }
     }
 
@@ -145,7 +145,7 @@ namespace MapControl
         public UpsSouthProjection(string crsId)
         {
             CrsId = crsId;
-            IsNorth = false;
+            Hemisphere = Hemisphere.South;
         }
     }
 }

MapControl/Shared/Wgs84AutoUtmProjection.cs

@@ -3,8 +3,9 @@
 namespace MapControl
 {
     /// <summary>
-    /// WGS84 Universal Transverse Mercator Projection with
+    /// WGS84 Universal Transverse Mercator Projection with automatic zone selection from
-    /// automatic zone selection from projection center.
+    /// the projection center. If the CRS Id passed to the constructor is null or empty,
+    /// appropriate CRS Ids EPSG:32601 to EPSG:32660 and EPSG:32701 to EPSG:32760 are used.
     /// </summary>
     public class Wgs84AutoUtmProjection : Wgs84UtmProjection
     {
@@ -18,11 +19,8 @@ namespace MapControl
             // XAML needs parameterless constructor
         }
 
-        /// <summary>
-        /// When the crsId parameter is null or empty, the projection will use EPSG:32***.
-        /// </summary>
         public Wgs84AutoUtmProjection(string crsId)
-            : base(31, true)
+            : base(31, Hemisphere.North)
         {
             autoCrsId = crsId;
 
@@ -43,11 +41,11 @@ namespace MapControl
 
                     var lon = Location.NormalizeLongitude(value.Longitude);
                     var zone = (int)Math.Floor(lon / 6d) + 31;
-                    var north = value.Latitude >= 0d;
+                    var hemisphere = value.Latitude >= 0d ? Hemisphere.North : Hemisphere.South;
 
-                    if (Zone != zone || IsNorth != north)
+                    if (Zone != zone || Hemisphere != hemisphere)
                     {
-                        SetZone(zone, north);
+                        SetZone(zone, hemisphere);
 
                         if (!string.IsNullOrEmpty(autoCrsId))
                         {

MapControl/Shared/Wgs84UtmProjection.cs

@@ -2,6 +2,12 @@
 
 namespace MapControl
 {
+    public enum Hemisphere
+    {
+        North,
+        South
+    }
+
     /// <summary>
     /// WGS84 Universal Transverse Mercator Projection.
     /// </summary>
@@ -15,11 +21,11 @@ namespace MapControl
         public const int LastZoneSouthEpsgCode = 32700 + LastZone;
 
         public int Zone { get; private set; }
-        public bool IsNorth { get; private set; }
+        public Hemisphere Hemisphere { get; private set; }
 
-        public Wgs84UtmProjection(int zone, bool north)
+        public Wgs84UtmProjection(int zone, Hemisphere hemisphere)
         {
-            SetZone(zone, north);
+            SetZone(zone, hemisphere);
 
             EquatorialRadius = Wgs84EquatorialRadius;
             Flattening = Wgs84Flattening;
@@ -27,7 +33,7 @@ namespace MapControl
             FalseEasting = 5e5;
         }
 
-        protected void SetZone(int zone, bool north)
+        protected void SetZone(int zone, Hemisphere hemisphere)
         {
             if (zone < FirstZone || zone > LastZone)
             {
@@ -35,10 +41,10 @@ namespace MapControl
             }
 
             Zone = zone;
-            IsNorth = north;
+            Hemisphere = hemisphere;
-            CrsId = $"EPSG:{(north ? 32600 : 32700) + zone}";
+            CrsId = $"EPSG:{(hemisphere == Hemisphere.North ? 32600 : 32700) + zone}";
             CentralMeridian = zone * 6d - 183d;
-            FalseNorthing = north ? 0d : 1e7;
+            FalseNorthing = hemisphere == Hemisphere.North ? 0d : 1e7;
         }
     }
 }

MapProjections/Shared/Wgs84AutoUtmProjection.cs

@@ -3,8 +3,9 @@
 namespace MapControl.Projections
 {
     /// <summary>
-    /// WGS84 Universal Transverse Mercator Projection with
+    /// WGS84 Universal Transverse Mercator Projection with automatic zone selection from
-    /// automatic zone selection from projection center.
+    /// the projection center. If the CRS Id passed to the constructor is null or empty,
+    /// appropriate CRS Ids EPSG:32601 to EPSG:32660 and EPSG:32701 to EPSG:32760 are used.
     /// </summary>
     public class Wgs84AutoUtmProjection : Wgs84UtmProjection
     {
@@ -16,11 +17,8 @@ namespace MapControl.Projections
             // XAML needs parameterless constructor
         }
 
-        /// <summary>
-        /// When the crsId parameter is null or empty, the projection will use EPSG:32***.
-        /// </summary>
         public Wgs84AutoUtmProjection(string crsId)
-            : base(31, true)
+            : base(31, Hemisphere.North)
         {
             autoCrsId = crsId;
 
@@ -41,11 +39,11 @@ namespace MapControl.Projections
 
                     var lon = Location.NormalizeLongitude(value.Longitude);
                     var zone = (int)Math.Floor(lon / 6d) + 31;
-                    var north = value.Latitude >= 0d;
+                    var hemisphere = value.Latitude >= 0d ? Hemisphere.North : Hemisphere.South;
 
-                    if (Zone != zone || IsNorth != north)
+                    if (Zone != zone || Hemisphere != hemisphere)
                     {
-                        SetZone(zone, north);
+                        SetZone(zone, hemisphere);
 
                         if (!string.IsNullOrEmpty(autoCrsId))
                         {

MapProjections/Shared/Wgs84UtmProjection.cs

@@ -16,14 +16,14 @@ namespace MapControl.Projections
         public const int LastZoneSouthEpsgCode = 32700 + LastZone;
 
         public int Zone { get; private set; }
-        public bool IsNorth { get; private set; }
+        public Hemisphere Hemisphere { get; private set; }
 
-        public Wgs84UtmProjection(int zone, bool north)
+        public Wgs84UtmProjection(int zone, Hemisphere hemisphere)
         {
-            SetZone(zone, north);
+            SetZone(zone, hemisphere);
         }
 
-        protected void SetZone(int zone, bool north)
+        protected void SetZone(int zone, Hemisphere hemisphere)
         {
             if (zone < FirstZone || zone > LastZone)
             {
@@ -31,8 +31,8 @@ namespace MapControl.Projections
             }
 
             Zone = zone;
-            IsNorth = north;
+            Hemisphere = hemisphere;
-            CoordinateSystem = ProjectedCoordinateSystem.WGS84_UTM(Zone, IsNorth);
+            CoordinateSystem = ProjectedCoordinateSystem.WGS84_UTM(Zone, hemisphere == Hemisphere.North);
         }
     }
 }