Version 4: Upgrade to VS 2017

MapControl/Shared/MapGraticule.cs

@@ -0,0 +1,83 @@
+// 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.UI.Xaml;
+#else
+using System.Windows;
+#endif
+
+namespace MapControl
+{
+    /// <summary>
+    /// Draws a graticule overlay.
+    /// </summary>
+    public partial class MapGraticule : MapOverlay
+    {
+        public static readonly DependencyProperty MinLineDistanceProperty = DependencyProperty.Register(
+            nameof(MinLineDistance), typeof(double), typeof(MapGraticule), new PropertyMetadata(150d));
+
+        /// <summary>
+        /// Minimum graticule line distance in pixels. The default value is 150.
+        /// </summary>
+        public double MinLineDistance
+        {
+            get { return (double)GetValue(MinLineDistanceProperty); }
+            set { SetValue(MinLineDistanceProperty, value); }
+        }
+
+        private double GetLineDistance()
+        {
+            var minDistance = MinLineDistance / MapProjection.DegreesToViewportScale(ParentMap.ZoomLevel);
+            var scale = 1d;
+
+            if (minDistance < 1d)
+            {
+                scale = minDistance < 1d / 60d ? 3600d : 60d;
+                minDistance *= scale;
+            }
+
+            var lineDistances = new double[] { 1d, 2d, 5d, 10d, 15d, 30d, 60d };
+            var i = 0;
+
+            while (i < lineDistances.Length - 1 && lineDistances[i] < minDistance)
+            {
+                i++;
+            }
+
+            return lineDistances[i] / scale;
+        }
+
+        private static string GetLabelFormat(double lineDistance)
+        {
+            if (lineDistance < 1d / 60d)
+            {
+                return "{0} {1}°{2:00}'{3:00}\"";
+            }
+            
+            if (lineDistance < 1d)
+            {
+                return "{0} {1}°{2:00}'";
+            }
+            
+            return "{0} {1}°";
+        }
+
+        private static string GetLabelText(double value, string format, string hemispheres)
+        {
+            var hemisphere = hemispheres[0];
+
+            if (value < -1e-8) // ~1mm
+            {
+                value = -value;
+                hemisphere = hemispheres[1];
+            }
+
+            var seconds = (int)Math.Round(value * 3600d);
+
+            return string.Format(format, hemisphere, seconds / 3600, (seconds / 60) % 60, seconds % 60);
+        }
+    }
+}