Version 4: Upgrade to VS 2017

MapControl/Shared/WebMercatorProjection.cs

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+// 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 Web Mercator Projection.
+    /// Longitude values are transformed linearly to X values in meters, by multiplying with MetersPerDegree.
+    /// Latitude values in the interval [-MaxLatitude .. MaxLatitude] are transformed to Y values in meters
+    /// in the interval [-R*pi .. R*pi], R=Wgs84EquatorialRadius.
+    /// </summary>
+    public class WebMercatorProjection : MapProjection
+    {
+        public WebMercatorProjection()
+            : this("EPSG:3857")
+        {
+        }
+
+        public WebMercatorProjection(string crsId)
+        {
+            CrsId = crsId;
+            IsWebMercator = true;
+            LongitudeScale = MetersPerDegree;
+            MaxLatitude = YToLatitude(180d);
+        }
+
+        public override double GetViewportScale(double zoomLevel)
+        {
+            return DegreesToViewportScale(zoomLevel) / MetersPerDegree;
+        }
+
+        public override Point GetMapScale(Location location)
+        {
+            var scale = ViewportScale / Math.Cos(location.Latitude * Math.PI / 180d);
+
+            return new Point(scale, scale);
+        }
+
+        public override Point LocationToPoint(Location location)
+        {
+            return new Point(
+                MetersPerDegree * location.Longitude,
+                MetersPerDegree * LatitudeToY(location.Latitude));
+        }
+
+        public override Location PointToLocation(Point point)
+        {
+            return new Location(
+                YToLatitude(point.Y / MetersPerDegree),
+                point.X / MetersPerDegree);
+        }
+
+        public override Location TranslateLocation(Location location, Point translation)
+        {
+            var scaleX = MetersPerDegree * ViewportScale;
+            var scaleY = scaleX / Math.Cos(location.Latitude * Math.PI / 180d);
+
+            return new Location(
+                location.Latitude - translation.Y / scaleY,
+                location.Longitude + translation.X / scaleX);
+        }
+
+        public static double LatitudeToY(double latitude)
+        {
+            var lat = latitude * Math.PI / 180d;
+
+            return latitude <= -90d ? double.NegativeInfinity
+                : latitude >= 90d ? double.PositiveInfinity
+                : Math.Log(Math.Tan((latitude + 90d) * Math.PI / 360d)) / Math.PI * 180d;
+        }
+
+        public static double YToLatitude(double y)
+        {
+            return Math.Atan(Math.Exp(y * Math.PI / 180d)) / Math.PI * 360d - 90d;
+        }
+    }
+}