Added AutoUtmProjection

MapProjections/Shared/AutoUtmProjection.cs

@@ -0,0 +1,50 @@
+// XAML Map Control - https://github.com/ClemensFischer/XAML-Map-Control
+// © 2022 Clemens Fischer
+// Licensed under the Microsoft Public License (Ms-PL)
+
+using ProjNet.CoordinateSystems;
+using System.Windows;
+
+namespace MapControl.Projections
+{
+    public class AutoUtmProjection : GeoApiProjection
+    {
+        private int zoneNumber;
+        private bool zoneIsNorth;
+
+        public AutoUtmProjection()
+        {
+            UpdateZone();
+        }
+
+        public override Point LocationToMap(Location location)
+        {
+            UpdateZone();
+            return base.LocationToMap(location);
+        }
+
+        public override Location MapToLocation(Point point)
+        {
+            UpdateZone();
+            return base.MapToLocation(point);
+        }
+
+        private void UpdateZone()
+        {
+            var north = Center.Latitude >= 0d;
+            var lon = Location.NormalizeLongitude(Center.Longitude);
+            var zone = (int)(lon + 180d) / 6 + 1;
+
+            if (zoneNumber != zone || zoneIsNorth != north)
+            {
+                zoneNumber = zone;
+                zoneIsNorth = north;
+
+                CoordinateSystem = ProjectedCoordinateSystem.WGS84_UTM(zoneNumber, zoneIsNorth);
+                CrsId = "AUTO2:42001";
+
+                System.Diagnostics.Debug.WriteLine(CoordinateSystem.Name);
+            }
+        }
+    }
+}

MapProjections/Shared/Ed50UtmProjection.cs

@@ -9,11 +9,6 @@ namespace MapControl.Projections
     public class Ed50UtmProjection : GeoApiProjection
     {
         public Ed50UtmProjection(int zone)
-        {
-            SetZone(zone);
-        }
-
-        protected void SetZone(int zone)
         {
             if (zone < 28 || zone > 38)
             {

MapProjections/Shared/Etrs89UtmProjection.cs

@@ -9,11 +9,6 @@ namespace MapControl.Projections
     public class Etrs89UtmProjection : GeoApiProjection
     {
         public Etrs89UtmProjection(int zone)
-        {
-            SetZone(zone);
-        }
-
-        protected void SetZone(int zone)
         {
             if (zone < 28 || zone > 38)
             {

MapProjections/Shared/GeoApiProjectionFactory.cs

@@ -10,6 +10,7 @@ namespace MapControl.Projections
     {
         public const int WorldMercator = 3395;
         public const int WebMercator = 3857;
+        public const int AutoUtm = 42001;
         public const int Ed50UtmFirst = 23028;
         public const int Ed50UtmLast = 23038;
         public const int Etrs89UtmFirst = 25828;
@@ -26,16 +27,19 @@ namespace MapControl.Projections
         public override MapProjection GetProjection(string crsId)
         {
             MapProjection projection = null;
+            var str = crsId.StartsWith("EPSG:") ? crsId.Substring(5)
+                    : crsId.StartsWith("AUTO2:") ? crsId.Substring(6)
+                    : null;
 
-            if (crsId.StartsWith("EPSG:") && int.TryParse(crsId.Substring(5), out int epsgCode))
+            if (int.TryParse(str, out int code))
             {
-                if (CoordinateSystemWkts.TryGetValue(epsgCode, out string wkt))
+                if (CoordinateSystemWkts.TryGetValue(code, out string wkt))
                 {
                     projection = new GeoApiProjection(wkt);
                 }
                 else
                 {
-                    switch (epsgCode)
+                    switch (code)
                     {
                         case WorldMercator:
                             projection = new WorldMercatorProjection();
@@ -45,20 +49,24 @@ namespace MapControl.Projections
                             projection = new WebMercatorProjection();
                             break;
 
+                        case AutoUtm:
+                            projection = new AutoUtmProjection();
+                            break;
+
                         case int c when c >= Ed50UtmFirst && c <= Ed50UtmLast:
-                            projection = new Ed50UtmProjection(epsgCode % 100);
+                            projection = new Ed50UtmProjection(code % 100);
                             break;
 
                         case int c when c >= Etrs89UtmFirst && c <= Etrs89UtmLast:
-                            projection = new Etrs89UtmProjection(epsgCode % 100);
+                            projection = new Etrs89UtmProjection(code % 100);
                             break;
 
                         case int c when c >= Wgs84UtmNorthFirst && c <= Wgs84UtmNorthLast:
-                            projection = new Wgs84UtmProjection(epsgCode % 100, true);
+                            projection = new Wgs84UtmProjection(code % 100, true);
                             break;
 
                         case int c when c >= Wgs84UtmSouthFirst && c <= Wgs84UtmSouthLast:
-                            projection = new Wgs84UtmProjection(epsgCode % 100, false);
+                            projection = new Wgs84UtmProjection(code % 100, false);
                             break;
 
                         case Wgs84UpsNorth:

MapProjections/Shared/Wgs84UtmProjection.cs

@@ -10,11 +10,6 @@ namespace MapControl.Projections
     public class Wgs84UtmProjection : GeoApiProjection
     {
         public Wgs84UtmProjection(int zone, bool north)
-        {
-            SetZone(zone, north);
-        }
-
-        protected void SetZone(int zone, bool north)
         {
             if (zone < 1 || zone > 60)
             {

MapProjections/UWP/MapProjections.UWP.csproj

@@ -40,6 +40,9 @@
     <RestoreProjectStyle>PackageReference</RestoreProjectStyle>
   </PropertyGroup>
   <ItemGroup>
+    <Compile Include="..\Shared\AutoUtmProjection.cs">
+      <Link>AutoUtmProjection.cs</Link>
+    </Compile>
     <Compile Include="..\Shared\Ed50UtmProjection.cs">
       <Link>Ed50UtmProjection.cs</Link>
     </Compile>