Moved Matrix creation to ViewTransform

MapControl/Shared/MapBase.cs

@@ -198,14 +198,21 @@ namespace MapControl
         public ViewTransform ViewTransform { get; } = new ViewTransform();
 
         /// <summary>
-        /// Gets the map scale as the horizontal and vertical scaling factors from geographic
-        /// coordinates to view coordinates at the specified location, as pixels per meter.
+        /// Gets the map scale as horizontal and vertical scaling factors from meters to
+        /// view coordinates at the specified location.
         /// </summary>
         public Point GetScale(Location location)
         {
-            var relativeScale = MapProjection.GetRelativeScale(location);
+            return ViewTransform.GetMapScale(MapProjection.GetRelativeScale(location));
+        }
 
-            return new Point(ViewTransform.Scale * relativeScale.X, ViewTransform.Scale * relativeScale.Y);
+        /// <summary>
+        /// Gets a transform Matrix from meters to view coordinates for scaling and rotating
+        /// objects that are anchored at a Location.
+        /// </summary>
+        public Matrix GetMapTransform(Location location)
+        {
+            return ViewTransform.GetMapTransform(MapProjection.GetRelativeScale(location));
         }
 
         /// <summary>
@@ -554,7 +561,7 @@ namespace MapControl
                     }
                 }
 
-                SetViewScale(ViewTransform.Scale);
+                ViewScale = ViewTransform.Scale;
 
                 // Check if view center has moved across 180° longitude.
                 //

MapControl/Shared/ViewTransform.cs

@@ -54,21 +54,10 @@ namespace MapControl
         public Matrix ViewToMapMatrix { get; private set; }
 
         /// <summary>
-        /// Transforms a Point from projected map coordinates to view coordinates.
+        /// Initializes a ViewTransform from a map center point in projected coordinates,
+        /// a view conter point, a scaling factor from projected coordinates to view coordinates
+        /// and a rotation angle in degrees.
         /// </summary>
-        public Point MapToView(Point point)
-        {
-            return MapToViewMatrix.Transform(point);
-        }
-
-        /// <summary>
-        /// Transforms a Point from view coordinates to projected map coordinates.
-        /// </summary>
-        public Point ViewToMap(Point point)
-        {
-            return ViewToMapMatrix.Transform(point);
-        }
-
         public void SetTransform(Point mapCenter, Point viewCenter, double scale, double rotation)
         {
             Scale = scale;
@@ -85,6 +74,46 @@ namespace MapControl
             ViewToMapMatrix = transform;
         }
 
+        /// <summary>
+        /// Transforms a Point from projected map coordinates to view coordinates.
+        /// </summary>
+        public Point MapToView(Point point)
+        {
+            return MapToViewMatrix.Transform(point);
+        }
+
+        /// <summary>
+        /// Transforms a Point from view coordinates to projected map coordinates.
+        /// </summary>
+        public Point ViewToMap(Point point)
+        {
+            return ViewToMapMatrix.Transform(point);
+        }
+
+        /// <summary>
+        /// Gets scaling factors from meters to view coordinates for a relative map scale.
+        /// </summary>
+        public Point GetMapScale(Point relativeScale)
+        {
+            return new Point(Scale * relativeScale.X, Scale * relativeScale.Y);
+        }
+
+        /// <summary>
+        /// Gets a transform Matrix from meters to view coordinates for a relative map scale.
+        /// </summary>
+        public Matrix GetMapTransform(Point relativeScale)
+        {
+            var scale = GetMapScale(relativeScale);
+
+            var transform = new Matrix(scale.X, 0d, 0d, scale.Y, 0d, 0d);
+            transform.Rotate(Rotation);
+
+            return transform;
+        }
+
+        /// <summary>
+        /// Gets the transform Matrix for the RenderTranform of a MapTileLayer.
+        /// </summary>
         public Matrix GetTileLayerTransform(double tileMatrixScale, Point tileMatrixTopLeft, Point tileMatrixOrigin)
         {
             // Tile matrix origin in map coordinates.
@@ -106,6 +135,9 @@ namespace MapControl
             return transform;
         }
 
+        /// <summary>
+        /// Gets the index bounds of a tile matrix.
+        /// </summary>
         public Rect GetTileMatrixBounds(double tileMatrixScale, Point tileMatrixTopLeft, Size viewSize)
         {
             // View origin in map coordinates.
@@ -128,5 +160,17 @@ namespace MapControl
             return new MatrixTransform { Matrix = transform }
                 .TransformBounds(new Rect(0d, 0d, viewSize.Width, viewSize.Height));
         }
+
+        internal static Matrix CreateTransformMatrix(
+            double translation1X, double translation1Y,
+            double rotation,
+            double translation2X, double translation2Y)
+        {
+            var transform = new Matrix(1d, 0d, 0d, 1d, translation1X, translation1Y);
+            transform.Rotate(rotation);
+            transform.Translate(translation2X, translation2Y);
+
+            return transform;
+        }
     }
 }

MapControl/Shared/WmsImageLayer.cs

@@ -9,18 +9,13 @@ using System.Linq;
 using System.Threading.Tasks;
 using System.Xml.Linq;
 #if AVALONIA
-using Avalonia.Controls;
-using Avalonia.Media;
-using Avalonia.Threading;
 using DependencyProperty = Avalonia.AvaloniaProperty;
 using FrameworkElement = Avalonia.Controls.Control;
 using ImageSource = Avalonia.Media.IImage;
 #elif WINUI
-using Windows.Foundation;
 using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Media;
 #elif UWP
-using Windows.Foundation;
 using Windows.UI.Xaml;
 using Windows.UI.Xaml.Media;
 #else
@@ -284,16 +279,12 @@ namespace MapControl
             }
 
             var viewRect = GetViewRect(rect.Value);
-#if AVALONIA
-            var transform
-                = Matrix.CreateTranslation(-viewSize.Width / 2d, -viewSize.Height / 2d)
-                * Matrix.CreateRotation(-viewRect.Rotation * Math.PI / 180d)
-                * Matrix.CreateTranslation(viewRect.Rect.Width / 2d, viewRect.Rect.Height / 2d);
-#else
-            var transform = new Matrix(1d, 0d, 0d, 1d, -viewSize.Width / 2d, -viewSize.Height / 2d);
-            transform.Rotate(-viewRect.Rotation);
-            transform.Translate(viewRect.Rect.Width / 2d, viewRect.Rect.Height / 2d);
-#endif
+
+            var transform = ViewTransform.CreateTransformMatrix(
+                -viewSize.Width / 2d, -viewSize.Height / 2d,
+                -viewRect.Rotation,
+                viewRect.Rect.Width / 2d, viewRect.Rect.Height / 2d);
+
             var imagePos = transform.Transform(position);
 
             var queryParameters = new Dictionary<string, string>