From 03e0258f18ac01f2b9c43dc73fed1e5b823cfae9 Mon Sep 17 00:00:00 2001
From: ClemensFischer <fischer.clemens@gmail.com>
Date: Mon, 5 Jan 2026 21:27:00 +0100
Subject: [PATCH] Updated ViewTransform

---
 MapControl/Avalonia/MapGraticule.Avalonia.cs  |  8 ++--
 MapControl/Shared/MapBase.cs                  | 24 +---------
 MapControl/Shared/MapGraticule.cs             |  2 +-
 MapControl/Shared/MapImageLayer.cs            |  3 +-
 .../Matrix.WinUI.cs => Shared/Matrix.cs}      | 33 ++++++++------
 MapControl/Shared/ViewTransform.cs            | 45 +++++++------------
 MapControl/Shared/WmsImageLayer.cs            | 13 ++----
 MapControl/WPF/MapControl.WPF.csproj          |  1 +
 8 files changed, 49 insertions(+), 80 deletions(-)
 rename MapControl/{WinUI/Matrix.WinUI.cs => Shared/Matrix.cs} (76%)

diff --git a/MapControl/Avalonia/MapGraticule.Avalonia.cs b/MapControl/Avalonia/MapGraticule.Avalonia.cs
index 5d05aaf7..aa07cef0 100644
--- a/MapControl/Avalonia/MapGraticule.Avalonia.cs
+++ b/MapControl/Avalonia/MapGraticule.Avalonia.cs
@@ -83,9 +83,11 @@ namespace MapControl
                         var y1 = -StrokeThickness / 2d - latText.Height;
                         var y2 = StrokeThickness / 2d;
 
-                        using var pushState = drawingContext.PushTransform(
-                            Matrix.CreateRotation(Matrix.ToRadians(label.Rotation)) *
-                            Matrix.CreateTranslation(label.X, label.Y));
+                        var transform = new Matrix(1d, 0d, 0d, 1d, 0d, 0d);
+                        transform.Rotate(label.Rotation);
+                        transform.Translate(label.X, label.Y);
+
+                        using var pushState = drawingContext.PushTransform(transform);
 
                         drawingContext.DrawText(latText, new Point(x, y1));
                         drawingContext.DrawText(lonText, new Point(x, y2));
diff --git a/MapControl/Shared/MapBase.cs b/MapControl/Shared/MapBase.cs
index c7766b8d..0a66bac2 100644
--- a/MapControl/Shared/MapBase.cs
+++ b/MapControl/Shared/MapBase.cs
@@ -238,32 +238,12 @@ namespace MapControl
             return MapProjection.MapToLocation(ViewTransform.ViewToMapMatrix.Transform(point));
         }
 
-        /// <summary>
-        /// Gets a Rect in projected map coordinates that covers a rectangle in view coordinates.
-        /// </summary>
-        public Rect ViewRectToMap(double x, double y, double width, double height)
-        {
-            var viewToMap = ViewTransform.ViewToMapMatrix;
-
-            var p1 = viewToMap.Transform(new Point(x, y));
-            var p2 = viewToMap.Transform(new Point(x, y + height));
-            var p3 = viewToMap.Transform(new Point(x + width, y));
-            var p4 = viewToMap.Transform(new Point(x + width, y + height));
-
-            var x1 = Math.Min(p1.X, Math.Min(p2.X, Math.Min(p3.X, p4.X)));
-            var y1 = Math.Min(p1.Y, Math.Min(p2.Y, Math.Min(p3.Y, p4.Y)));
-            var x2 = Math.Max(p1.X, Math.Max(p2.X, Math.Max(p3.X, p4.X)));
-            var y2 = Math.Max(p1.Y, Math.Max(p2.Y, Math.Max(p3.Y, p4.Y)));
-
-            return new Rect(x1, y1, x2 - x1, y2 - y1);
-        }
-
         /// <summary>
         /// Gets a BoundingBox in geographic coordinates that covers a rectangle in view coordinates.
         /// </summary>
-        public BoundingBox ViewRectToBoundingBox(double x, double y, double width, double height)
+        public BoundingBox ViewToBoundingBox(Rect rect)
         {
-            return MapProjection.MapToBoundingBox(ViewRectToMap(x, y, width, height));
+            return MapProjection.MapToBoundingBox(ViewTransform.ViewToMapMatrix.TransformBounds(rect));
         }
 
         /// <summary>
diff --git a/MapControl/Shared/MapGraticule.cs b/MapControl/Shared/MapGraticule.cs
index 458c5407..4e72a4a6 100644
--- a/MapControl/Shared/MapGraticule.cs
+++ b/MapControl/Shared/MapGraticule.cs
@@ -171,7 +171,7 @@ namespace MapControl
 
         private void DrawCylindricalGraticule(PathFigureCollection figures, List<Label> labels)
         {
-            var boundingBox = ParentMap.ViewRectToBoundingBox(0d, 0d, ParentMap.ActualWidth, ParentMap.ActualHeight);
+            var boundingBox = ParentMap.ViewToBoundingBox(new Rect(0d, 0d, ParentMap.ActualWidth, ParentMap.ActualHeight));
             var latLabelStart = Math.Ceiling(boundingBox.South / lineDistance) * lineDistance;
             var lonLabelStart = Math.Ceiling(boundingBox.West / lineDistance) * lineDistance;
 
diff --git a/MapControl/Shared/MapImageLayer.cs b/MapControl/Shared/MapImageLayer.cs
index c268a979..f44d0b91 100644
--- a/MapControl/Shared/MapImageLayer.cs
+++ b/MapControl/Shared/MapImageLayer.cs
@@ -191,8 +191,7 @@ namespace MapControl
                     var height = ParentMap.ActualHeight * RelativeImageSize;
                     var x = (ParentMap.ActualWidth - width) / 2d;
                     var y = (ParentMap.ActualHeight - height) / 2d;
-                    var mapRect = ParentMap.ViewRectToMap(x, y, width, height);
-
+                    var mapRect = ParentMap.ViewTransform.ViewToMapMatrix.TransformBounds(new Rect(x, y, width, height));
                     boundingBox = ParentMap.MapProjection.MapToBoundingBox(mapRect);
 
                     if (boundingBox != null)
diff --git a/MapControl/WinUI/Matrix.WinUI.cs b/MapControl/Shared/Matrix.cs
similarity index 76%
rename from MapControl/WinUI/Matrix.WinUI.cs
rename to MapControl/Shared/Matrix.cs
index 5f42ce3a..073efb67 100644
--- a/MapControl/WinUI/Matrix.WinUI.cs
+++ b/MapControl/Shared/Matrix.cs
@@ -1,14 +1,17 @@
 using System;
 #if UWP
-using WindowsUI = Windows.UI;
-#else
-using WindowsUI = Microsoft.UI;
+using PlatformMatrix = Windows.UI.Xaml.Media.Matrix;
+#elif WINUI
+using PlatformMatrix = Microsoft.UI.Xaml.Media.Matrix;
+#elif AVALONIA
+using Avalonia;
+using PlatformMatrix = Avalonia.Matrix;
 #endif
 
 namespace MapControl
 {
     /// <summary>
-    /// Replaces Windows.UI.Xaml.Media.Matrix for double floating point precision.
+    /// Replaces Windows/Microsoft.UI.Xaml.Media.Matrix to expose manipulation methods.
     /// </summary>
     public struct Matrix(double m11, double m12, double m21, double m22, double offsetX, double offsetY)
     {
@@ -19,14 +22,18 @@ namespace MapControl
         public double OffsetX { get; private set; } = offsetX;
         public double OffsetY { get; private set; } = offsetY;
 
-        public static implicit operator WindowsUI.Xaml.Media.Matrix(Matrix m)
+        public static implicit operator Matrix(PlatformMatrix m)
         {
-            return new WindowsUI.Xaml.Media.Matrix(m.M11, m.M12, m.M21, m.M22, m.OffsetX, m.OffsetY);
+#if AVALONIA
+            return new Matrix(m.M11, m.M12, m.M21, m.M22, m.M31, m.M32);
+#else
+            return new Matrix(m.M11, m.M12, m.M21, m.M22, m.OffsetX, m.OffsetY);
+#endif
         }
 
-        public static implicit operator Matrix(WindowsUI.Xaml.Media.Matrix m)
+        public static implicit operator PlatformMatrix(Matrix m)
         {
-            return new Matrix(m.M11, m.M12, m.M21, m.M22, m.OffsetX, m.OffsetY);
+            return new PlatformMatrix(m.M11, m.M12, m.M21, m.M22, m.OffsetX, m.OffsetY);
         }
 
         public readonly Point Transform(Point p)
@@ -44,15 +51,13 @@ namespace MapControl
 
         public void Rotate(double angle)
         {
-            angle = (angle % 360d) / 180d * Math.PI;
-
             if (angle != 0d)
             {
-                var cos = Math.Cos(angle);
-                var sin = Math.Sin(angle);
-
-                // Multiply(new Matrix(cos, sin, -sin, cos, 0d, 0d));
+                var cos = Math.Cos(angle * Math.PI / 180d);
+                var sin = Math.Sin(angle * Math.PI / 180d);
 
+                // equivalent to Multiply(new Matrix(cos, sin, -sin, cos, 0d, 0d));
+                //
                 SetMatrix(
                     cos * M11 - sin * M12,
                     sin * M11 + cos * M12,
diff --git a/MapControl/Shared/ViewTransform.cs b/MapControl/Shared/ViewTransform.cs
index c8768087..f282b8ee 100644
--- a/MapControl/Shared/ViewTransform.cs
+++ b/MapControl/Shared/ViewTransform.cs
@@ -49,20 +49,12 @@ namespace MapControl
             Rotation = ((rotation % 360d) + 360d) % 360d;
 
             var transform = new Matrix(scale, 0d, 0d, -scale, -scale * mapCenter.X, scale * mapCenter.Y);
-#if AVALONIA
-            MapToViewMatrix = transform
-                * Matrix.CreateRotation(Matrix.ToRadians(Rotation))
-                * Matrix.CreateTranslation(viewCenter.X, viewCenter.Y);
-
-            ViewToMapMatrix = MapToViewMatrix.Invert();
-#else
             transform.Rotate(Rotation);
             transform.Translate(viewCenter.X, viewCenter.Y);
             MapToViewMatrix = transform;
 
             transform.Invert();
             ViewToMapMatrix = transform;
-#endif
         }
 
         /// <summary>
@@ -71,12 +63,8 @@ namespace MapControl
         public Matrix GetMapTransform(Point relativeScale)
         {
             var transform = new Matrix(Scale * relativeScale.X, 0d, 0d, Scale * relativeScale.Y, 0d, 0d);
-#if AVALONIA
-            return transform * Matrix.CreateRotation(Matrix.ToRadians(Rotation));
-#else
             transform.Rotate(Rotation);
             return transform;
-#endif
         }
 
         /// <summary>
@@ -94,17 +82,11 @@ namespace MapControl
             //
             var viewOrigin = MapToViewMatrix.Transform(mapOrigin);
 
-            var transformScale = Scale / tileMatrixScale;
-            var transform = new Matrix(transformScale, 0d, 0d, transformScale, 0d, 0d);
-#if AVALONIA
-            return transform
-                * Matrix.CreateRotation(Matrix.ToRadians(Rotation))
-                * Matrix.CreateTranslation(viewOrigin.X, viewOrigin.Y);
-#else
+            var scale = Scale / tileMatrixScale;
+            var transform = new Matrix(scale, 0d, 0d, scale, 0d, 0d);
             transform.Rotate(Rotation);
             transform.Translate(viewOrigin.X, viewOrigin.Y);
             return transform;
-#endif
         }
 
         /// <summary>
@@ -121,20 +103,25 @@ namespace MapControl
             var originOffsetX = tileMatrixScale * (origin.X - tileMatrixTopLeft.X);
             var originOffsetY = tileMatrixScale * (tileMatrixTopLeft.Y - origin.Y);
 
-            var transformScale = tileMatrixScale / Scale;
-            var transform = new Matrix(transformScale, 0d, 0d, transformScale, 0d, 0d);
-            var viewRect = new Rect(0d, 0d, viewWidth, viewHeight);
-#if AVALONIA
-            return viewRect.TransformToAABB(transform
-                * Matrix.CreateRotation(Matrix.ToRadians(-Rotation))
-                * Matrix.CreateTranslation(originOffsetX, originOffsetY));
-#else
+            var scale = tileMatrixScale / Scale;
+            var transform = new Matrix(scale, 0d, 0d, scale, 0d, 0d);
             transform.Rotate(-Rotation);
             transform.Translate(originOffsetX, originOffsetY);
 
             // Transform view bounds to tile pixel bounds.
             //
-            return new MatrixTransform { Matrix = transform }.TransformBounds(viewRect);
+            return transform.TransformBounds(new Rect(0d, 0d, viewWidth, viewHeight));
+        }
+    }
+
+    public static class MatrixExtension
+    {
+        public static Rect TransformBounds(this Matrix transform, Rect rect)
+        {
+#if AVALONIA
+            return rect.TransformToAABB(transform);
+#else
+            return new MatrixTransform { Matrix = transform }.TransformBounds(rect);
 #endif
         }
     }
diff --git a/MapControl/Shared/WmsImageLayer.cs b/MapControl/Shared/WmsImageLayer.cs
index c41754f2..f8ca9475 100644
--- a/MapControl/Shared/WmsImageLayer.cs
+++ b/MapControl/Shared/WmsImageLayer.cs
@@ -211,7 +211,6 @@ namespace MapControl
                     var width2 = bbox.Width - width1;
                     var bbox1 = new Rect(x, bbox.Y, width1, bbox.Height);
                     var bbox2 = new Rect(xMin, bbox.Y, width2, bbox.Height);
-
                     var uri1 = GetMapRequestUri(bbox1);
                     var uri2 = GetMapRequestUri(bbox2);
 
@@ -265,21 +264,17 @@ namespace MapControl
         {
             var width = ParentMap.ActualWidth;
             var height = ParentMap.ActualHeight;
-            var bbox = ParentMap.ViewRectToMap(0d, 0d, width, height);
+            var bbox = ParentMap.ViewTransform.ViewToMapMatrix.TransformBounds(new Rect(0d, 0d, width, height));
 
             if (ParentMap.ViewTransform.Rotation != 0d)
             {
-                var transform = new Matrix(1d, 0d, 0d, 1d, -width / 2d, -height / 2d);
                 width = ParentMap.ViewTransform.Scale * bbox.Width;
                 height = ParentMap.ViewTransform.Scale * bbox.Height;
-#if AVALONIA
-                transform = transform
-                    * Matrix.CreateRotation(Matrix.ToRadians(-ParentMap.ViewTransform.Rotation))
-                    * Matrix.CreateTranslation(width / 2d, height / 2d);
-#else
+
+                var transform = new Matrix(1d, 0d, 0d, 1d, -ParentMap.ActualWidth / 2d, -ParentMap.ActualHeight / 2d);
                 transform.Rotate(-ParentMap.ViewTransform.Rotation);
                 transform.Translate(width / 2d, height / 2d);
-#endif
+
                 position = transform.Transform(position);
             }
 
diff --git a/MapControl/WPF/MapControl.WPF.csproj b/MapControl/WPF/MapControl.WPF.csproj
index 557847a0..f792b74b 100644
--- a/MapControl/WPF/MapControl.WPF.csproj
+++ b/MapControl/WPF/MapControl.WPF.csproj
@@ -17,6 +17,7 @@
     </ItemGroup>
 
     <ItemGroup>
+        <Compile Remove="..\Shared\Matrix.cs" />
         <Compile Remove="..\Shared\PolygonCollection.cs" />
     </ItemGroup>