From f11c71799f4e0985bef19b010c549f2283b6c9c8 Mon Sep 17 00:00:00 2001
From: ClemensF <fischer.clemens@gmail.com>
Date: Thu, 21 Nov 2013 21:16:29 +0100
Subject: [PATCH] Version 1.10.0: Removed Location.TransformedLatitude, cleanup
 in MapBase and TileImageLoader.

---
 .../FileDbCache/Properties/AssemblyInfo.cs    |   4 +-
 .../ImageFileCache/Properties/AssemblyInfo.cs |   4 +-
 MapControl/Location.cs                        |  36 ++----
 MapControl/MapBase.cs                         | 112 ++++++++----------
 MapControl/MapGraticule.Silverlight.WinRT.cs  |   7 +-
 MapControl/MapGraticule.WPF.cs                |  67 ++++-------
 MapControl/MapPanel.cs                        |  17 +--
 MapControl/MapRectangle.cs                    |  10 +-
 MapControl/MapTransform.cs                    |  22 ++++
 MapControl/MercatorTransform.cs               |  33 +++---
 MapControl/Properties/AssemblyInfo.cs         |   4 +-
 MapControl/TileImageLoader.WPF.cs             |  65 +++++-----
 MapControl/WinRT/Properties/AssemblyInfo.cs   |   4 +-
 .../Properties/AssemblyInfo.cs                |   4 +-
 .../Properties/AssemblyInfo.cs                |   4 +-
 .../Properties/AssemblyInfo.cs                |   4 +-
 .../Properties/AssemblyInfo.cs                |   4 +-
 .../WpfApplication/Properties/AssemblyInfo.cs |   4 +-
 .../WpfApplication/WpfApplication.csproj      |   1 -
 19 files changed, 187 insertions(+), 219 deletions(-)

diff --git a/Caching/FileDbCache/Properties/AssemblyInfo.cs b/Caching/FileDbCache/Properties/AssemblyInfo.cs
index 3ee6117a..b1541348 100644
--- a/Caching/FileDbCache/Properties/AssemblyInfo.cs
+++ b/Caching/FileDbCache/Properties/AssemblyInfo.cs
@@ -8,8 +8,8 @@ using System.Runtime.InteropServices;
 [assembly: AssemblyCompany("Clemens Fischer")]
 [assembly: AssemblyCopyright("Copyright © Clemens Fischer 2012-2013")]
 [assembly: AssemblyTrademark("")]
-[assembly: AssemblyVersion("1.9.2")]
-[assembly: AssemblyFileVersion("1.9.2")]
+[assembly: AssemblyVersion("1.10.0")]
+[assembly: AssemblyFileVersion("1.10.0")]
 [assembly: AssemblyConfiguration("")]
 [assembly: AssemblyCulture("")]
 [assembly: ComVisible(false)]
diff --git a/Caching/ImageFileCache/Properties/AssemblyInfo.cs b/Caching/ImageFileCache/Properties/AssemblyInfo.cs
index e2c89f78..15708cd0 100644
--- a/Caching/ImageFileCache/Properties/AssemblyInfo.cs
+++ b/Caching/ImageFileCache/Properties/AssemblyInfo.cs
@@ -8,8 +8,8 @@ using System.Runtime.InteropServices;
 [assembly: AssemblyCompany("Clemens Fischer")]
 [assembly: AssemblyCopyright("Copyright © Clemens Fischer 2012-2013")]
 [assembly: AssemblyTrademark("")]
-[assembly: AssemblyVersion("1.9.2")]
-[assembly: AssemblyFileVersion("1.9.2")]
+[assembly: AssemblyVersion("1.10.0")]
+[assembly: AssemblyFileVersion("1.10.0")]
 [assembly: AssemblyConfiguration("")]
 [assembly: AssemblyCulture("")]
 [assembly: ComVisible(false)]
diff --git a/MapControl/Location.cs b/MapControl/Location.cs
index 3e21188d..d6aa1883 100644
--- a/MapControl/Location.cs
+++ b/MapControl/Location.cs
@@ -15,15 +15,6 @@ namespace MapControl
 #endif
     public partial class Location
     {
-        /// <summary>
-        /// TransformedLatitude is set by the Transform methods in MercatorTransform.
-        /// It holds the transformed latitude value to avoid redundant recalculation. 
-        /// </summary>
-#if !SILVERLIGHT && !NETFX_CORE
-        [NonSerialized]
-#endif
-        internal double TransformedLatitude = double.NaN;
-
         private double latitude;
         private double longitude;
 
@@ -33,24 +24,14 @@ namespace MapControl
 
         public Location(double latitude, double longitude)
         {
-            this.latitude = Math.Min(Math.Max(latitude, -90d), 90d);
-            this.longitude = longitude;
-        }
-
-        internal Location(double transformedLatitude, double latitude, double longitude)
-            : this(latitude, longitude)
-        {
-            TransformedLatitude = transformedLatitude;
+            Latitude = latitude;
+            Longitude = longitude;
         }
 
         public double Latitude
         {
             get { return latitude; }
-            set
-            {
-                latitude = Math.Min(Math.Max(value, -90d), 90d);
-                TransformedLatitude = double.NaN;
-            }
+            set { latitude = Math.Min(Math.Max(value, -90d), 90d); }
         }
 
         public double Longitude
@@ -79,7 +60,16 @@ namespace MapControl
 
         public static double NormalizeLongitude(double longitude)
         {
-            return (longitude >= -180d && longitude <= 180d) ? longitude : ((longitude + 180d) % 360d + 360d) % 360d - 180d;
+            if (longitude > 180)
+            {
+                longitude = ((longitude - 180d) % 360d) - 180d;
+            }
+            else if (longitude < -180d)
+            {
+                longitude = ((longitude + 180d) % 360d) + 180d;
+            }
+
+            return longitude;
         }
     }
 }
diff --git a/MapControl/MapBase.cs b/MapControl/MapBase.cs
index ad16a8fd..07000926 100644
--- a/MapControl/MapBase.cs
+++ b/MapControl/MapBase.cs
@@ -26,6 +26,8 @@ namespace MapControl
     /// </summary>
     public partial class MapBase : MapPanel
     {
+        private const double MaximumZoomLevel = 22d;
+
         public static TimeSpan AnimationDuration = TimeSpan.FromSeconds(0.5);
         public static EasingFunctionBase AnimationEasingFunction = new QuadraticEase { EasingMode = EasingMode.EaseOut };
 
@@ -394,14 +396,10 @@ namespace MapControl
         /// </summary>
         public void ZoomMap(Point origin, double zoomLevel)
         {
-            SetTransformOrigin(origin);
-
-            var targetZoomLevel = TargetZoomLevel;
-            TargetZoomLevel = zoomLevel;
-
-            if (TargetZoomLevel == targetZoomLevel) // TargetZoomLevel might be coerced
+            if (zoomLevel >= MinZoomLevel && zoomLevel <= MaxZoomLevel)
             {
-                ResetTransformOrigin();
+                SetTransformOrigin(origin);
+                TargetZoomLevel = zoomLevel;
             }
         }
 
@@ -572,48 +570,38 @@ namespace MapControl
             internalPropertyChange = false;
         }
 
-        private bool CoerceLocation(ref Location location, double latitudeEpsilon = 0d)
+        private void AdjustCenterProperty(DependencyProperty property, ref Location center)
         {
-            if (location == null)
-            {
-                location = new Location();
-                return true;
-            }
-
-            var maxLatitude = mapTransform.MaxLatitude + latitudeEpsilon;
-            var latitude = Math.Min(Math.Max(location.Latitude, -maxLatitude), maxLatitude);
-            var longitude = Location.NormalizeLongitude(location.Longitude);
-
-            if (location.Latitude != latitude || location.Longitude != longitude)
-            {
-                location.Latitude = latitude;
-                location.Longitude = longitude;
-                return true;
-            }
-
-            return false;
-        }
-
-        private void CoerceCenterProperty(DependencyProperty property, ref Location center)
-        {
-            if (CoerceLocation(ref center))
+            if (center == null)
             {
+                center = new Location();
                 InternalSetValue(property, center);
             }
+            else
+            {
+                var latitude = Math.Min(Math.Max(center.Latitude, -mapTransform.MaxLatitude), mapTransform.MaxLatitude);
+                var longitude = Location.NormalizeLongitude(center.Longitude);
+
+                if (center.Latitude != latitude || center.Longitude != longitude)
+                {
+                    center = new Location(latitude, longitude);
+                    InternalSetValue(property, center);
+                }
+            }
         }
 
         private void CenterPropertyChanged(Location center)
         {
             if (!internalPropertyChange)
             {
-                CoerceCenterProperty(CenterProperty, ref center);
+                AdjustCenterProperty(CenterProperty, ref center);
                 ResetTransformOrigin();
                 UpdateTransform();
 
                 if (centerAnimation == null)
                 {
                     InternalSetValue(TargetCenterProperty, center);
-                    InternalSetValue(CenterPointProperty, new Point(center.Longitude, center.Latitude));
+                    InternalSetValue(CenterPointProperty, MapTransform.Transform(center));
                 }
             }
         }
@@ -622,7 +610,7 @@ namespace MapControl
         {
             if (!internalPropertyChange)
             {
-                CoerceCenterProperty(TargetCenterProperty, ref targetCenter);
+                AdjustCenterProperty(TargetCenterProperty, ref targetCenter);
 
                 if (targetCenter.Latitude != Center.Latitude || targetCenter.Longitude != Center.Longitude)
                 {
@@ -634,8 +622,8 @@ namespace MapControl
                     // animate private CenterPoint property by PointAnimation
                     centerAnimation = new PointAnimation
                     {
-                        From = new Point(Center.Longitude, Center.Latitude),
-                        To = new Point(targetCenter.Longitude, targetCenter.Latitude),
+                        From = MapTransform.Transform(Center),
+                        To = MapTransform.Transform(targetCenter, Center.Longitude),
                         Duration = AnimationDuration,
                         EasingFunction = AnimationEasingFunction,
                         FillBehavior = FillBehavior.HoldEnd
@@ -655,7 +643,7 @@ namespace MapControl
                 centerAnimation = null;
 
                 InternalSetValue(CenterProperty, TargetCenter);
-                InternalSetValue(CenterPointProperty, new Point(TargetCenter.Longitude, TargetCenter.Latitude));
+                InternalSetValue(CenterPointProperty, MapTransform.Transform(TargetCenter));
                 RemoveAnimation(CenterPointProperty); // remove holding animation in WPF
 
                 ResetTransformOrigin();
@@ -667,7 +655,8 @@ namespace MapControl
         {
             if (!internalPropertyChange)
             {
-                InternalSetValue(CenterProperty, new Location(centerPoint.Y, centerPoint.X));
+                centerPoint.X = Location.NormalizeLongitude(centerPoint.X);
+                InternalSetValue(CenterProperty, MapTransform.Transform(centerPoint));
                 ResetTransformOrigin();
                 UpdateTransform();
             }
@@ -675,11 +664,9 @@ namespace MapControl
 
         private void MinZoomLevelPropertyChanged(double minZoomLevel)
         {
-            var coercedValue = Math.Min(Math.Max(minZoomLevel, 0d), MaxZoomLevel);
-
-            if (coercedValue != minZoomLevel)
+            if (minZoomLevel < 0d || minZoomLevel > MaxZoomLevel)
             {
-                minZoomLevel = coercedValue;
+                minZoomLevel = Math.Min(Math.Max(minZoomLevel, 0d), MaxZoomLevel);
                 InternalSetValue(MinZoomLevelProperty, minZoomLevel);
             }
 
@@ -691,11 +678,9 @@ namespace MapControl
 
         private void MaxZoomLevelPropertyChanged(double maxZoomLevel)
         {
-            var coercedValue = Math.Min(Math.Max(maxZoomLevel, MinZoomLevel), 22d);
-
-            if (coercedValue != maxZoomLevel)
+            if (maxZoomLevel < MinZoomLevel || maxZoomLevel > MaximumZoomLevel)
             {
-                maxZoomLevel = coercedValue;
+                maxZoomLevel = Math.Min(Math.Max(maxZoomLevel, MinZoomLevel), MaximumZoomLevel);
                 InternalSetValue(MaxZoomLevelProperty, maxZoomLevel);
             }
 
@@ -705,13 +690,11 @@ namespace MapControl
             }
         }
 
-        private void CoerceZoomLevelProperty(DependencyProperty property, ref double zoomLevel)
+        private void AdjustZoomLevelProperty(DependencyProperty property, ref double zoomLevel)
         {
-            var coercedValue = Math.Min(Math.Max(zoomLevel, MinZoomLevel), MaxZoomLevel);
-
-            if (coercedValue != zoomLevel)
+            if (zoomLevel < MinZoomLevel || zoomLevel > MaxZoomLevel)
             {
-                zoomLevel = coercedValue;
+                zoomLevel = Math.Min(Math.Max(zoomLevel, MinZoomLevel), MaxZoomLevel);
                 InternalSetValue(property, zoomLevel);
             }
         }
@@ -720,7 +703,7 @@ namespace MapControl
         {
             if (!internalPropertyChange)
             {
-                CoerceZoomLevelProperty(ZoomLevelProperty, ref zoomLevel);
+                AdjustZoomLevelProperty(ZoomLevelProperty, ref zoomLevel);
                 UpdateTransform();
 
                 if (zoomLevelAnimation == null)
@@ -734,7 +717,7 @@ namespace MapControl
         {
             if (!internalPropertyChange)
             {
-                CoerceZoomLevelProperty(TargetZoomLevelProperty, ref targetZoomLevel);
+                AdjustZoomLevelProperty(TargetZoomLevelProperty, ref targetZoomLevel);
 
                 if (targetZoomLevel != ZoomLevel)
                 {
@@ -772,13 +755,11 @@ namespace MapControl
             }
         }
 
-        private void CoerceHeadingProperty(DependencyProperty property, ref double heading)
+        private void AdjustHeadingProperty(DependencyProperty property, ref double heading)
         {
-            var coercedValue = (heading >= -180d && heading <= 360d) ? heading : (((heading % 360d) + 360d) % 360d);
-
-            if (coercedValue != heading)
+            if (heading < -180d || heading > 360d)
             {
-                heading = coercedValue;
+                heading = ((heading % 360d) + 360d) % 360d;
                 InternalSetValue(property, heading);
             }
         }
@@ -787,7 +768,7 @@ namespace MapControl
         {
             if (!internalPropertyChange)
             {
-                CoerceHeadingProperty(HeadingProperty, ref heading);
+                AdjustHeadingProperty(HeadingProperty, ref heading);
                 UpdateTransform();
 
                 if (headingAnimation == null)
@@ -801,7 +782,7 @@ namespace MapControl
         {
             if (!internalPropertyChange)
             {
-                CoerceHeadingProperty(TargetHeadingProperty, ref targetHeading);
+                AdjustHeadingProperty(TargetHeadingProperty, ref targetHeading);
 
                 if (targetHeading != Heading)
                 {
@@ -858,11 +839,18 @@ namespace MapControl
             {
                 center = ViewportPointToLocation(new Point(RenderSize.Width / 2d, RenderSize.Height / 2d));
 
-                var coerced = CoerceLocation(ref center, 1e-3);
+                var latitude = center.Latitude;
+                center.Latitude = Math.Min(Math.Max(latitude, -mapTransform.MaxLatitude), mapTransform.MaxLatitude);
 
                 InternalSetValue(CenterProperty, center);
 
-                if (coerced)
+                if (centerAnimation == null)
+                {
+                    InternalSetValue(TargetCenterProperty, center);
+                    InternalSetValue(CenterPointProperty, MapTransform.Transform(center));
+                }
+
+                if (center.Latitude != latitude)
                 {
                     ResetTransformOrigin();
                     scale = SetViewportTransform(center);
diff --git a/MapControl/MapGraticule.Silverlight.WinRT.cs b/MapControl/MapGraticule.Silverlight.WinRT.cs
index ffab582b..ff01f086 100644
--- a/MapControl/MapGraticule.Silverlight.WinRT.cs
+++ b/MapControl/MapGraticule.Silverlight.WinRT.cs
@@ -179,9 +179,6 @@ namespace MapControl
 
                 if (!lineStart.Equals(graticuleStart) || !lineEnd.Equals(graticuleEnd))
                 {
-                    ParentMap.MapTransform.Transform(lineStart); // get lineStart.TransformedLatitude
-                    ParentMap.MapTransform.Transform(lineEnd); // get lineEnd.TransformedLatitude
-
                     graticuleStart = lineStart;
                     graticuleEnd = lineEnd;
 
@@ -216,14 +213,14 @@ namespace MapControl
                     {
                         var figure = new PathFigure
                         {
-                            StartPoint = ParentMap.MapTransform.Transform(new Location(lineStart.TransformedLatitude, lineStart.Latitude, lon)),
+                            StartPoint = ParentMap.MapTransform.Transform(new Location(lineStart.Latitude, lon)),
                             IsClosed = false,
                             IsFilled = false
                         };
 
                         figure.Segments.Add(new LineSegment
                         {
-                            Point = ParentMap.MapTransform.Transform(new Location(lineEnd.TransformedLatitude, lineEnd.Latitude, lon)),
+                            Point = ParentMap.MapTransform.Transform(new Location(lineEnd.Latitude, lon)),
                         });
 
                         geometry.Figures.Add(figure);
diff --git a/MapControl/MapGraticule.WPF.cs b/MapControl/MapGraticule.WPF.cs
index 0cef838c..99bc10ee 100644
--- a/MapControl/MapGraticule.WPF.cs
+++ b/MapControl/MapGraticule.WPF.cs
@@ -12,28 +12,14 @@ namespace MapControl
 {
     public partial class MapGraticule : MapOverlay
     {
-        private class LonLabel
+        private class Label
         {
-            public readonly double Longitude;
+            public readonly double Position;
             public readonly string Text;
 
-            public LonLabel(double longitude, string text)
+            public Label(double position, string text)
             {
-                Longitude = longitude;
-                Text = text;
-            }
-        }
-
-        private class LatLabel
-        {
-            public readonly double TransformedLatitude;
-            public readonly double Latitude;
-            public readonly string Text;
-
-            public LatLabel(double transformedLatitude, double latitude, string text)
-            {
-                TransformedLatitude = transformedLatitude;
-                Latitude = latitude;
+                Position = position;
                 Text = text;
             }
         }
@@ -59,10 +45,8 @@ namespace MapControl
             if (ParentMap != null)
             {
                 var bounds = ParentMap.ViewportTransform.Inverse.TransformBounds(new Rect(ParentMap.RenderSize));
-                var startPoint = new Point(bounds.X, bounds.Y);
-                var endPoint = new Point(bounds.X + bounds.Width, bounds.Y + bounds.Height);
-                var startLocation = ParentMap.MapTransform.Transform(startPoint);
-                var endLocation = ParentMap.MapTransform.Transform(endPoint);
+                var start = ParentMap.MapTransform.Transform(new Point(bounds.X, bounds.Y));
+                var end = ParentMap.MapTransform.Transform(new Point(bounds.X + bounds.Width, bounds.Y + bounds.Height));
                 var minSpacing = MinLineSpacing * 360d / (Math.Pow(2d, ParentMap.ZoomLevel) * TileSource.TileSize);
                 var spacing = LineSpacings[LineSpacings.Length - 1];
 
@@ -73,31 +57,28 @@ namespace MapControl
 
                 var labelFormat = spacing < 1d ? "{0} {1}°{2:00}'" : "{0} {1}°";
                 var labelStart = new Location(
-                    Math.Ceiling(startLocation.Latitude / spacing) * spacing,
-                    Math.Ceiling(startLocation.Longitude / spacing) * spacing);
+                    Math.Ceiling(start.Latitude / spacing) * spacing,
+                    Math.Ceiling(start.Longitude / spacing) * spacing);
 
-                var latLabels = new List<LatLabel>((int)((endLocation.Latitude - labelStart.Latitude) / spacing) + 1);
-                var lonLabels = new List<LonLabel>((int)((endLocation.Longitude - labelStart.Longitude) / spacing) + 1);
+                var latLabels = new List<Label>((int)((end.Latitude - labelStart.Latitude) / spacing) + 1);
+                var lonLabels = new List<Label>((int)((end.Longitude - labelStart.Longitude) / spacing) + 1);
 
-                for (var lat = labelStart.Latitude; lat <= endLocation.Latitude; lat += spacing)
+                for (var lat = labelStart.Latitude; lat <= end.Latitude; lat += spacing)
                 {
-                    var location = new Location(lat, startLocation.Longitude);
-                    var p1 = ParentMap.LocationToViewportPoint(location);
-                    location.Longitude = endLocation.Longitude;
-                    var p2 = ParentMap.LocationToViewportPoint(location);
-
-                    latLabels.Add(new LatLabel(location.TransformedLatitude, lat, CoordinateString(lat, labelFormat, "NS")));
-
-                    drawingContext.DrawLine(Pen, p1, p2);
-                }
-
-                for (var lon = labelStart.Longitude; lon <= endLocation.Longitude; lon += spacing)
-                {
-                    lonLabels.Add(new LonLabel(lon, CoordinateString(Location.NormalizeLongitude(lon), labelFormat, "EW")));
+                    latLabels.Add(new Label(lat, CoordinateString(lat, labelFormat, "NS")));
 
                     drawingContext.DrawLine(Pen,
-                        ParentMap.LocationToViewportPoint(new Location(startPoint.Y, startLocation.Latitude, lon)),
-                        ParentMap.LocationToViewportPoint(new Location(endPoint.Y, endLocation.Latitude, lon)));
+                        ParentMap.LocationToViewportPoint(new Location(lat, start.Longitude)),
+                        ParentMap.LocationToViewportPoint(new Location(lat, end.Longitude)));
+                }
+
+                for (var lon = labelStart.Longitude; lon <= end.Longitude; lon += spacing)
+                {
+                    lonLabels.Add(new Label(lon, CoordinateString(Location.NormalizeLongitude(lon), labelFormat, "EW")));
+
+                    drawingContext.DrawLine(Pen,
+                        ParentMap.LocationToViewportPoint(new Location(start.Latitude, lon)),
+                        ParentMap.LocationToViewportPoint(new Location(end.Latitude, lon)));
                 }
 
                 if (Foreground != null && Foreground != Brushes.Transparent && latLabels.Count > 0 && lonLabels.Count > 0)
@@ -126,7 +107,7 @@ namespace MapControl
                                 glyphRuns.Add(lonLabel.Text, lonGlyphRun);
                             }
 
-                            var position = ParentMap.LocationToViewportPoint(new Location(latLabel.TransformedLatitude, latLabel.Latitude, lonLabel.Longitude));
+                            var position = ParentMap.LocationToViewportPoint(new Location(latLabel.Position, lonLabel.Position));
 
                             drawingContext.PushTransform(new MatrixTransform(
                                 transform.M11, transform.M12, transform.M21, transform.M22, position.X, position.Y));
diff --git a/MapControl/MapPanel.cs b/MapControl/MapPanel.cs
index 0674d740..5fbba49e 100644
--- a/MapControl/MapPanel.cs
+++ b/MapControl/MapPanel.cs
@@ -151,21 +151,8 @@ namespace MapControl
 
             if (parentMap != null && location != null)
             {
-                // transform location before checking longitude to keep location.TransformedLatitude
-                var mapPosition = parentMap.MapTransform.Transform(location);
-                mapPosition.X = Location.NormalizeLongitude(mapPosition.X);
-
-                var centerOffset = mapPosition.X - parentMap.Center.Longitude; // keep viewport position near map center
-               
-                if (centerOffset > 180d)
-                {
-                    mapPosition.X -= 360d;
-                }
-                else if (centerOffset < -180d)
-                {
-                    mapPosition.X += 360d;
-                }
-
+                // keep viewport position near map center
+                var mapPosition = parentMap.MapTransform.Transform(location, parentMap.Center.Longitude);
                 viewportPosition = parentMap.ViewportTransform.Transform(mapPosition);
                 element.SetValue(ViewportPositionProperty, viewportPosition);
             }
diff --git a/MapControl/MapRectangle.cs b/MapControl/MapRectangle.cs
index 9987a00f..10197546 100644
--- a/MapControl/MapRectangle.cs
+++ b/MapControl/MapRectangle.cs
@@ -18,12 +18,12 @@ namespace MapControl
     /// </summary>
     public partial class MapRectangle : MapPath
     {
-        private const double geometryScale = 1e6;
+        private const double GeometryScale = 1e6;
 
         private static readonly ScaleTransform geometryScaleTransform = new ScaleTransform
         {
-            ScaleX = 1d / geometryScale,
-            ScaleY = 1d / geometryScale
+            ScaleX = 1d / GeometryScale,
+            ScaleY = 1d / GeometryScale
         };
 
         public static readonly DependencyProperty SouthProperty = DependencyProperty.Register(
@@ -87,8 +87,8 @@ namespace MapControl
                 // Create a scaled RectangleGeometry due to inaccurate hit testing in WPF.
                 // See http://stackoverflow.com/a/19335624/1136211
 
-                geometry.Rect = new Rect(p1.X * geometryScale, p1.Y * geometryScale,
-                    (p2.X - p1.X) * geometryScale, (p2.Y - p1.Y) * geometryScale);
+                geometry.Rect = new Rect(p1.X * GeometryScale, p1.Y * GeometryScale,
+                    (p2.X - p1.X) * GeometryScale, (p2.Y - p1.Y) * GeometryScale);
 
                 var transform = new TransformGroup();
                 transform.Children.Add(geometryScaleTransform); // revert scaling
diff --git a/MapControl/MapTransform.cs b/MapControl/MapTransform.cs
index e136229e..cef59a3f 100644
--- a/MapControl/MapTransform.cs
+++ b/MapControl/MapTransform.cs
@@ -39,5 +39,27 @@ namespace MapControl
         /// Transforms a cartesian coordinate point to a geographic location.
         /// </summary>
         public abstract Location Transform(Point point);
+
+        /// <summary>
+        /// Transforms a geographic location to a cartesian coordinate point
+        /// with minumum distance to the specified reference longitude value.
+        /// </summary>
+        public Point Transform(Location location, double referenceLongitude)
+        {
+            var p = Transform(location);
+
+            p.X = Location.NormalizeLongitude(p.X);
+
+            if (p.X > referenceLongitude + 180d)
+            {
+                p.X -= 360d;
+            }
+            else if (p.X < referenceLongitude - 180d)
+            {
+                p.X += 360d;
+            }
+
+            return p;
+        }
     }
 }
diff --git a/MapControl/MercatorTransform.cs b/MapControl/MercatorTransform.cs
index ce72fa20..ea98646e 100644
--- a/MapControl/MercatorTransform.cs
+++ b/MapControl/MercatorTransform.cs
@@ -41,29 +41,30 @@ namespace MapControl
 
         public override Point Transform(Location location)
         {
-            if (double.IsNaN(location.TransformedLatitude))
+            double latitude;
+
+            if (location.Latitude <= -90d)
             {
-                if (location.Latitude <= -90d)
-                {
-                    location.TransformedLatitude = double.NegativeInfinity;
-                }
-                else if (location.Latitude >= 90d)
-                {
-                    location.TransformedLatitude = double.PositiveInfinity;
-                }
-                else
-                {
-                    var lat = location.Latitude * Math.PI / 180d;
-                    location.TransformedLatitude = Math.Log(Math.Tan(lat) + 1d / Math.Cos(lat)) / Math.PI * 180d;
-                }
+                latitude = double.NegativeInfinity;
+            }
+            else if (location.Latitude >= 90d)
+            {
+                latitude = double.PositiveInfinity;
+            }
+            else
+            {
+                latitude = location.Latitude * Math.PI / 180d;
+                latitude = Math.Log(Math.Tan(latitude) + 1d / Math.Cos(latitude)) / Math.PI * 180d;
             }
 
-            return new Point(location.Longitude, location.TransformedLatitude);
+            return new Point(location.Longitude, latitude);
         }
 
         public override Location Transform(Point point)
         {
-            return new Location(point.Y, Math.Atan(Math.Sinh(point.Y * Math.PI / 180d)) / Math.PI * 180d, point.X);
+            var latitude = Math.Atan(Math.Sinh(point.Y * Math.PI / 180d)) / Math.PI * 180d;
+
+            return new Location(latitude, point.X);
         }
     }
 }
diff --git a/MapControl/Properties/AssemblyInfo.cs b/MapControl/Properties/AssemblyInfo.cs
index 9b78a6bf..ae43703d 100644
--- a/MapControl/Properties/AssemblyInfo.cs
+++ b/MapControl/Properties/AssemblyInfo.cs
@@ -15,8 +15,8 @@ using System.Windows;
 [assembly: AssemblyCompany("Clemens Fischer")]
 [assembly: AssemblyCopyright("Copyright © Clemens Fischer 2012-2013")]
 [assembly: AssemblyTrademark("")]
-[assembly: AssemblyVersion("1.9.2")]
-[assembly: AssemblyFileVersion("1.9.2")]
+[assembly: AssemblyVersion("1.10.0")]
+[assembly: AssemblyFileVersion("1.10.0")]
 [assembly: AssemblyConfiguration("")]
 [assembly: AssemblyCulture("")]
 [assembly: ComVisible(false)]
diff --git a/MapControl/TileImageLoader.WPF.cs b/MapControl/TileImageLoader.WPF.cs
index 8ae081a3..5bfd0436 100644
--- a/MapControl/TileImageLoader.WPF.cs
+++ b/MapControl/TileImageLoader.WPF.cs
@@ -94,11 +94,11 @@ namespace MapControl
             {
                 if (!imageTileSource.CanLoadAsync) // call LoadImage in UI thread
                 {
+                    var setImageAction = new Action<Tile, ImageTileSource>((t, ts) => t.SetImageSource(LoadImage(ts, t), animateOpacity));
+
                     foreach (var tile in tiles)
                     {
-                        dispatcher.BeginInvoke(
-                            (Action<Tile, ImageTileSource>)((t, ts) => t.SetImageSource(LoadImage(ts, t), animateOpacity)),
-                            DispatcherPriority.Background, tile, imageTileSource);
+                        dispatcher.BeginInvoke(setImageAction, DispatcherPriority.Render, tile, imageTileSource);
                     }
 
                     return;
@@ -110,44 +110,48 @@ namespace MapControl
                 {
                     // no caching here: use default asynchronous downloading and caching done by WPF
 
+                    var setImageAction = new Action<Tile, TileSource>((t, ts) => t.SetImageSource(CreateImage(ts, t), animateOpacity));
+
                     foreach (var tile in tiles)
                     {
-                        dispatcher.BeginInvoke(
-                            (Action<Tile, TileSource>)((t, ts) => t.SetImageSource(CreateImage(ts, t), animateOpacity)),
-                            DispatcherPriority.Background, tile, tileSource);
+                        dispatcher.BeginInvoke(setImageAction, DispatcherPriority.Render, tile, tileSource);
                     }
 
                     return;
                 }
-
-                var outdatedTiles = new List<Tile>(tiles.Count);
-
-                foreach (var tile in tiles)
+                else
                 {
-                    var key = GetCacheKey(sourceName, tile);
-                    var buffer = Cache.Get(key) as byte[];
-                    var image = CreateImage(buffer);
+                    var setImageAction = new Action<Tile, ImageSource>((t, i) => t.SetImageSource(i, animateOpacity));
+                    var outdatedTiles = new List<Tile>(tiles.Count);
 
-                    if (image != null)
+                    foreach (var tile in tiles)
                     {
-                        dispatcher.BeginInvoke(
-                            (Action<Tile, ImageSource>)((t, i) => t.SetImageSource(i, animateOpacity)),
-                            DispatcherPriority.Background, tile, image);
+                        var key = GetCacheKey(sourceName, tile);
+                        var buffer = Cache.Get(key) as byte[];
+                        var image = CreateImage(buffer);
 
-                        long creationTime = BitConverter.ToInt64(buffer, 0);
-
-                        if (DateTime.FromBinary(creationTime) + CacheUpdateAge < DateTime.UtcNow)
+                        if (image != null)
                         {
-                            outdatedTiles.Add(tile); // update outdated cache
+                            var creationTime = BitConverter.ToInt64(buffer, 0);
+
+                            if (DateTime.FromBinary(creationTime) + CacheUpdateAge < DateTime.UtcNow)
+                            {
+                                dispatcher.Invoke(setImageAction, DispatcherPriority.Render, tile, image); // synchronously before enqueuing
+                                outdatedTiles.Add(tile); // update outdated cache
+                            }
+                            else
+                            {
+                                dispatcher.BeginInvoke(setImageAction, DispatcherPriority.Render, tile, image);
+                            }
+                        }
+                        else
+                        {
+                            pendingTiles.Enqueue(tile); // not yet cached
                         }
                     }
-                    else
-                    {
-                        pendingTiles.Enqueue(tile); // not yet cached
-                    }
-                }
 
-                tiles = outdatedTiles; // enqueue outdated tiles at last
+                    tiles = outdatedTiles; // enqueue outdated tiles at last
+                }
             }
 
             foreach (var tile in tiles)
@@ -165,6 +169,7 @@ namespace MapControl
 
         private void LoadPendingTiles(Dispatcher dispatcher, TileSource tileSource, string sourceName, bool animateOpacity)
         {
+            var setImageAction = new Action<Tile, ImageSource>((t, i) => t.SetImageSource(i, animateOpacity));
             var imageTileSource = tileSource as ImageTileSource;
             Tile tile;
 
@@ -197,9 +202,7 @@ namespace MapControl
 
                 if (image != null || !tile.HasImageSource) // do not set null if tile already has an image (from cache)
                 {
-                    dispatcher.BeginInvoke(
-                        (Action<Tile, ImageSource>)((t, i) => t.SetImageSource(i, animateOpacity)),
-                        DispatcherPriority.Background, tile, image);
+                    dispatcher.BeginInvoke(setImageAction, DispatcherPriority.Render, tile, image);
                 }
 
                 if (buffer != null && image != null)
@@ -308,7 +311,7 @@ namespace MapControl
 
                     using (var memoryStream = length > 0 ? new MemoryStream(length + sizeof(long)) : new MemoryStream())
                     {
-                        long creationTime = DateTime.UtcNow.ToBinary();
+                        var creationTime = DateTime.UtcNow.ToBinary();
 
                         memoryStream.Write(BitConverter.GetBytes(creationTime), 0, sizeof(long));
                         responseStream.CopyTo(memoryStream);
diff --git a/MapControl/WinRT/Properties/AssemblyInfo.cs b/MapControl/WinRT/Properties/AssemblyInfo.cs
index 4d516b8c..952a4778 100644
--- a/MapControl/WinRT/Properties/AssemblyInfo.cs
+++ b/MapControl/WinRT/Properties/AssemblyInfo.cs
@@ -8,8 +8,8 @@ using System.Runtime.InteropServices;
 [assembly: AssemblyCompany("Clemens Fischer")]
 [assembly: AssemblyCopyright("Copyright © Clemens Fischer 2012-2013")]
 [assembly: AssemblyTrademark("")]
-[assembly: AssemblyVersion("1.9.2")]
-[assembly: AssemblyFileVersion("1.9.2")]
+[assembly: AssemblyVersion("1.10.0")]
+[assembly: AssemblyFileVersion("1.10.0")]
 [assembly: AssemblyConfiguration("")]
 [assembly: AssemblyCulture("")]
 [assembly: ComVisible(false)]
diff --git a/SampleApps/SilverlightApplication.Web/Properties/AssemblyInfo.cs b/SampleApps/SilverlightApplication.Web/Properties/AssemblyInfo.cs
index 48129432..ef2ba4cb 100644
--- a/SampleApps/SilverlightApplication.Web/Properties/AssemblyInfo.cs
+++ b/SampleApps/SilverlightApplication.Web/Properties/AssemblyInfo.cs
@@ -8,8 +8,8 @@ using System.Runtime.InteropServices;
 [assembly: AssemblyCompany("Clemens Fischer")]
 [assembly: AssemblyCopyright("Copyright © Clemens Fischer 2012-2013")]
 [assembly: AssemblyTrademark("")]
-[assembly: AssemblyVersion("1.9.2")]
-[assembly: AssemblyFileVersion("1.9.2")]
+[assembly: AssemblyVersion("1.10.0")]
+[assembly: AssemblyFileVersion("1.10.0")]
 [assembly: AssemblyConfiguration("")]
 [assembly: AssemblyCulture("")]
 [assembly: ComVisible(false)]
diff --git a/SampleApps/SilverlightApplication/Properties/AssemblyInfo.cs b/SampleApps/SilverlightApplication/Properties/AssemblyInfo.cs
index 75b7dd97..bb0e06d5 100644
--- a/SampleApps/SilverlightApplication/Properties/AssemblyInfo.cs
+++ b/SampleApps/SilverlightApplication/Properties/AssemblyInfo.cs
@@ -8,8 +8,8 @@ using System.Runtime.InteropServices;
 [assembly: AssemblyCompany("Clemens Fischer")]
 [assembly: AssemblyCopyright("Copyright © Clemens Fischer 2012-2013")]
 [assembly: AssemblyTrademark("")]
-[assembly: AssemblyVersion("1.9.2")]
-[assembly: AssemblyFileVersion("1.9.2")]
+[assembly: AssemblyVersion("1.10.0")]
+[assembly: AssemblyFileVersion("1.10.0")]
 [assembly: AssemblyConfiguration("")]
 [assembly: AssemblyCulture("")]
 [assembly: ComVisible(false)]
diff --git a/SampleApps/StoreApplication/Properties/AssemblyInfo.cs b/SampleApps/StoreApplication/Properties/AssemblyInfo.cs
index 389f87c9..ab726094 100644
--- a/SampleApps/StoreApplication/Properties/AssemblyInfo.cs
+++ b/SampleApps/StoreApplication/Properties/AssemblyInfo.cs
@@ -8,8 +8,8 @@ using System.Runtime.InteropServices;
 [assembly: AssemblyCompany("Clemens Fischer")]
 [assembly: AssemblyCopyright("Copyright © Clemens Fischer 2012-2013")]
 [assembly: AssemblyTrademark("")]
-[assembly: AssemblyVersion("1.9.2")]
-[assembly: AssemblyFileVersion("1.9.2")]
+[assembly: AssemblyVersion("1.10.0")]
+[assembly: AssemblyFileVersion("1.10.0")]
 [assembly: AssemblyConfiguration("")]
 [assembly: AssemblyCulture("")]
 [assembly: ComVisible(false)]
diff --git a/SampleApps/SurfaceApplication/Properties/AssemblyInfo.cs b/SampleApps/SurfaceApplication/Properties/AssemblyInfo.cs
index 526fc669..30363e1d 100644
--- a/SampleApps/SurfaceApplication/Properties/AssemblyInfo.cs
+++ b/SampleApps/SurfaceApplication/Properties/AssemblyInfo.cs
@@ -8,8 +8,8 @@ using System.Runtime.InteropServices;
 [assembly: AssemblyCompany("Clemens Fischer")]
 [assembly: AssemblyCopyright("Copyright © Clemens Fischer 2012-2013")]
 [assembly: AssemblyTrademark("")]
-[assembly: AssemblyVersion("1.9.2")]
-[assembly: AssemblyFileVersion("1.9.2")]
+[assembly: AssemblyVersion("1.10.0")]
+[assembly: AssemblyFileVersion("1.10.0")]
 [assembly: AssemblyConfiguration("")]
 [assembly: AssemblyCulture("")]
 [assembly: ComVisible(false)]
diff --git a/SampleApps/WpfApplication/Properties/AssemblyInfo.cs b/SampleApps/WpfApplication/Properties/AssemblyInfo.cs
index 1b3c9a40..4605bc71 100644
--- a/SampleApps/WpfApplication/Properties/AssemblyInfo.cs
+++ b/SampleApps/WpfApplication/Properties/AssemblyInfo.cs
@@ -8,8 +8,8 @@ using System.Runtime.InteropServices;
 [assembly: AssemblyCompany("Clemens Fischer")]
 [assembly: AssemblyCopyright("Copyright © Clemens Fischer 2012-2013")]
 [assembly: AssemblyTrademark("")]
-[assembly: AssemblyVersion("1.9.2")]
-[assembly: AssemblyFileVersion("1.9.2")]
+[assembly: AssemblyVersion("1.10.0")]
+[assembly: AssemblyFileVersion("1.10.0")]
 [assembly: AssemblyConfiguration("")]
 [assembly: AssemblyCulture("")]
 [assembly: ComVisible(false)]
diff --git a/SampleApps/WpfApplication/WpfApplication.csproj b/SampleApps/WpfApplication/WpfApplication.csproj
index b1d94675..f42ac3e4 100644
--- a/SampleApps/WpfApplication/WpfApplication.csproj
+++ b/SampleApps/WpfApplication/WpfApplication.csproj
@@ -52,7 +52,6 @@
     <Compile Include="..\Common\ViewModel.cs">
       <Link>ViewModel.cs</Link>
     </Compile>
-    <Compile Include="ImageTileSource.cs" />
     <Page Include="MainWindow.xaml">
       <Generator>MSBuild:Compile</Generator>
       <SubType>Designer</SubType>