Version 4: Upgrade to VS 2017

MapControl/Shared/OrthographicProjection.cs

@@ -0,0 +1,74 @@
+// XAML Map Control - https://github.com/ClemensFischer/XAML-Map-Control
+// © 2017 Clemens Fischer
+// Licensed under the Microsoft Public License (Ms-PL)
+
+using System;
+#if WINDOWS_UWP
+using Windows.Foundation;
+#else
+using System.Windows;
+#endif
+
+namespace MapControl
+{
+    /// <summary>
+    /// Transforms map coordinates according to the Orthographic Projection.
+    /// </summary>
+    public class OrthographicProjection : AzimuthalProjection
+    {
+        public OrthographicProjection()
+            : this("AUTO2:42003")
+        {
+        }
+
+        public OrthographicProjection(string crsId)
+        {
+            CrsId = crsId;
+        }
+
+        public override Point LocationToPoint(Location location)
+        {
+            if (location.Equals(projectionCenter))
+            {
+                return new Point();
+            }
+
+            var lat0 = projectionCenter.Latitude * Math.PI / 180d;
+            var lat = location.Latitude * Math.PI / 180d;
+            var dLon = (location.Longitude - projectionCenter.Longitude) * Math.PI / 180d;
+
+            return new Point(
+                Wgs84EquatorialRadius * Math.Cos(lat) * Math.Sin(dLon),
+                Wgs84EquatorialRadius * (Math.Cos(lat0) * Math.Sin(lat) - Math.Sin(lat0) * Math.Cos(lat) * Math.Cos(dLon)));
+        }
+
+        public override Location PointToLocation(Point point)
+        {
+            if (point.X == 0d && point.Y == 0d)
+            {
+                return projectionCenter;
+            }
+
+            var x = point.X / Wgs84EquatorialRadius;
+            var y = point.Y / Wgs84EquatorialRadius;
+            var r2 = x * x + y * y;
+
+            if (r2 > 1d)
+            {
+                return new Location(double.NaN, double.NaN);
+            }
+
+            var r = Math.Sqrt(r2);
+            var sinC = r;
+            var cosC = Math.Sqrt(1 - r2);
+
+            var lat0 = projectionCenter.Latitude * Math.PI / 180d;
+            var cosLat0 = Math.Cos(lat0);
+            var sinLat0 = Math.Sin(lat0);
+
+            return new Location(
+                180d / Math.PI * Math.Asin(cosC * sinLat0 + y * sinC * cosLat0 / r),
+                180d / Math.PI * Math.Atan2(x * sinC, r * cosC * cosLat0 - y * sinC * sinLat0) + projectionCenter.Longitude);
+        }
+    }
+}