From f841e42e397c168a9c1c61f2d0e6f466f86c9e28 Mon Sep 17 00:00:00 2001
From: Clemens <fischer.clemens@gmail.com>
Date: Mon, 7 Mar 2022 17:28:08 +0100
Subject: [PATCH] Fixed MapProjection.Center

---
 MapControl/Shared/MapBase.cs                  | 10 ++--------
 MapProjections/Shared/AutoUtmProjection.cs    |  2 ++
 MapProjections/Shared/GeoApiProjection.cs     |  5 -----
 .../Shared/PolarStereographicProjection.cs    | 19 +++++++++++--------
 4 files changed, 15 insertions(+), 21 deletions(-)

diff --git a/MapControl/Shared/MapBase.cs b/MapControl/Shared/MapBase.cs
index e0729b1f..2bafd8a7 100644
--- a/MapControl/Shared/MapBase.cs
+++ b/MapControl/Shared/MapBase.cs
@@ -734,10 +734,7 @@ namespace MapControl
             var viewScale = ViewTransform.ZoomLevelToScale(ZoomLevel);
             var projection = MapProjection;
 
-            if (projection.Type == MapProjectionType.Azimuthal)
-            {
-                projection.Center = ProjectionCenter ?? Center;
-            }
+            projection.Center = ProjectionCenter ?? Center;
 
             var mapCenter = projection.LocationToMap(transformCenter ?? Center);
 
@@ -770,10 +767,7 @@ namespace MapControl
                         {
                             ResetTransformCenter();
 
-                            if (projection.Type == MapProjectionType.Azimuthal)
-                            {
-                                projection.Center = ProjectionCenter ?? Center;
-                            }
+                            projection.Center = ProjectionCenter ?? Center;
 
                             mapCenter = projection.LocationToMap(center);
 
diff --git a/MapProjections/Shared/AutoUtmProjection.cs b/MapProjections/Shared/AutoUtmProjection.cs
index 51720aa3..14c67142 100644
--- a/MapProjections/Shared/AutoUtmProjection.cs
+++ b/MapProjections/Shared/AutoUtmProjection.cs
@@ -24,12 +24,14 @@ namespace MapControl.Projections
         public override Point LocationToMap(Location location)
         {
             UpdateZone();
+
             return base.LocationToMap(location);
         }
 
         public override Location MapToLocation(Point point)
         {
             UpdateZone();
+
             return base.MapToLocation(point);
         }
 
diff --git a/MapProjections/Shared/GeoApiProjection.cs b/MapProjections/Shared/GeoApiProjection.cs
index b40b6506..580f7208 100644
--- a/MapProjections/Shared/GeoApiProjection.cs
+++ b/MapProjections/Shared/GeoApiProjection.cs
@@ -25,7 +25,6 @@ namespace MapControl.Projections
     public class GeoApiProjection : MapProjection
     {
         private ICoordinateSystem coordinateSystem;
-        private Location center;
         private double scaleFactor;
         private string bboxFormat;
 
@@ -101,10 +100,6 @@ namespace MapControl.Projections
                         Type = MapProjectionType.TransverseCylindrical;
                     }
 
-                    Center = new Location(
-                        centralParallel != null ? centralParallel.Value : 0d,
-                        centralMeridian != null ? centralMeridian.Value : 0d);
-
                     scaleFactor = 1d;
                     bboxFormat = "{0},{1},{2},{3}";
                 }
diff --git a/MapProjections/Shared/PolarStereographicProjection.cs b/MapProjections/Shared/PolarStereographicProjection.cs
index dbb38867..862a13ef 100644
--- a/MapProjections/Shared/PolarStereographicProjection.cs
+++ b/MapProjections/Shared/PolarStereographicProjection.cs
@@ -19,14 +19,15 @@ namespace MapControl.Projections
         private const double ConvergenceTolerance = 1e-6;
         private const int MaxIterations = 10;
 
+        public bool IsNorth { get; }
         public double ScaleFactor { get; }
         public double FalseEasting { get; }
         public double FalseNorthing { get; }
 
-        public PolarStereographicProjection(string crsId, bool isNorth, double scaleFactor, double falseEasting, double falseNorthing)
+        public PolarStereographicProjection(bool isNorth, double scaleFactor, double falseEasting, double falseNorthing)
         {
-            CrsId = crsId;
-            Center = new Location(isNorth ? 90d : -90d, 0d);
+            Type = MapProjectionType.Azimuthal;
+            IsNorth = isNorth;
             ScaleFactor = scaleFactor;
             FalseEasting = falseEasting;
             FalseNorthing = falseNorthing;
@@ -34,7 +35,7 @@ namespace MapControl.Projections
 
         public override Vector GetRelativeScale(Location location)
         {
-            var lat = Math.Sign(Center.Latitude) * location.Latitude * Math.PI / 180d;
+            var lat = (IsNorth ? location.Latitude : -location.Latitude) * Math.PI / 180d;
             var a = Wgs84EquatorialRadius;
             var e = Wgs84Eccentricity;
             var s = Math.Sqrt(Math.Pow(1 + e, 1 + e) * Math.Pow(1 - e, 1 - e));
@@ -52,7 +53,7 @@ namespace MapControl.Projections
             var lat = location.Latitude * Math.PI / 180d;
             var lon = location.Longitude * Math.PI / 180d;
 
-            if (Center.Latitude > 0d)
+            if (IsNorth)
             {
                 lon = Math.PI - lon;
             }
@@ -91,7 +92,7 @@ namespace MapControl.Projections
                 lat = newLat;
             }
 
-            if (Center.Latitude > 0d)
+            if (IsNorth)
             {
                 lon = Math.PI - lon;
             }
@@ -119,8 +120,9 @@ namespace MapControl.Projections
         public const string DefaultCrsId = "EPSG:32661";
 
         public UpsNorthProjection()
-            : base(DefaultCrsId, true, 0.994, 2e6, 2e6)
+            : base(true, 0.994, 2e6, 2e6)
         {
+            CrsId = DefaultCrsId;
         }
     }
 
@@ -132,8 +134,9 @@ namespace MapControl.Projections
         public const string DefaultCrsId = "EPSG:32761";
 
         public UpsSouthProjection()
-            : base(DefaultCrsId, false, 0.994, 2e6, 2e6)
+            : base(false, 0.994, 2e6, 2e6)
         {
+            CrsId = DefaultCrsId;
         }
     }
 }