Merge pull request #4813 from MarchingCube/geometry-drawing-optimize-getbounds

Cleanup and small optimization to GeometryDrawing

src/Avalonia.Visuals/ApiCompatBaseline.txt

@@ -2,6 +2,8 @@ Compat issues with assembly Avalonia.Visuals:
 MembersMustExist : Member 'public void Avalonia.Media.DrawingContext.DrawGlyphRun(Avalonia.Media.IBrush, Avalonia.Media.GlyphRun, Avalonia.Point)' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'public Avalonia.Media.Typeface Avalonia.Media.FontManager.GetOrAddTypeface(Avalonia.Media.FontFamily, Avalonia.Media.FontStyle, Avalonia.Media.FontWeight)' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'public Avalonia.Media.Typeface Avalonia.Media.FontManager.MatchCharacter(System.Int32, Avalonia.Media.FontStyle, Avalonia.Media.FontWeight, Avalonia.Media.FontFamily, System.Globalization.CultureInfo)' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'public Avalonia.Rect Avalonia.Media.Geometry.GetRenderBounds(Avalonia.Media.Pen)' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'public System.Boolean Avalonia.Media.Geometry.StrokeContains(Avalonia.Media.Pen, Avalonia.Point)' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'public Avalonia.Rect Avalonia.Media.GlyphRun.Bounds.get()' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'public Avalonia.StyledProperty<Avalonia.Point> Avalonia.StyledProperty<Avalonia.Point> Avalonia.Media.GlyphRunDrawing.BaselineOriginProperty' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'public Avalonia.Point Avalonia.Media.GlyphRunDrawing.BaselineOrigin.get()' does not exist in the implementation but it does exist in the contract.
@@ -34,4 +36,4 @@ InterfacesShouldHaveSameMembers : Interface member 'public System.Boolean Avalon
 MembersMustExist : Member 'public System.Boolean Avalonia.Platform.IFontManagerImpl.TryMatchCharacter(System.Int32, Avalonia.Media.FontStyle, Avalonia.Media.FontWeight, Avalonia.Media.FontFamily, System.Globalization.CultureInfo, Avalonia.Media.Fonts.FontKey)' does not exist in the implementation but it does exist in the contract.
 InterfacesShouldHaveSameMembers : Interface member 'public System.Boolean Avalonia.Platform.IFontManagerImpl.TryMatchCharacter(System.Int32, Avalonia.Media.FontStyle, Avalonia.Media.FontWeight, Avalonia.Media.FontFamily, System.Globalization.CultureInfo, Avalonia.Media.Typeface)' is present in the implementation but not in the contract.
 MembersMustExist : Member 'public Avalonia.Utilities.IRef<Avalonia.Platform.IRenderTargetBitmapImpl> Avalonia.Rendering.RenderLayer.Bitmap.get()' does not exist in the implementation but it does exist in the contract.
-Total Issues: 35
+Total Issues: 37

src/Avalonia.Visuals/Media/Drawing.cs

@@ -1,11 +1,19 @@
-using Avalonia.Platform;
-
-namespace Avalonia.Media
+namespace Avalonia.Media
 {
+    /// <summary>
+    /// Abstract class that describes a 2-D drawing.
+    /// </summary>
     public abstract class Drawing : AvaloniaObject
     {
+        /// <summary>
+        /// Draws this drawing to the given <see cref="DrawingContext"/>.
+        /// </summary>
+        /// <param name="context">The drawing context.</param>
         public abstract void Draw(DrawingContext context);
 
+        /// <summary>
+        /// Gets the drawing's bounding rectangle.
+        /// </summary>
         public abstract Rect GetBounds();
     }
 }

src/Avalonia.Visuals/Media/Geometry.cs

@@ -84,7 +84,7 @@ namespace Avalonia.Media
         /// </summary>
         /// <param name="pen">The stroke thickness.</param>
         /// <returns>The bounding rectangle.</returns>
-        public Rect GetRenderBounds(Pen pen) => PlatformImpl?.GetRenderBounds(pen) ?? Rect.Empty;
+        public Rect GetRenderBounds(IPen pen) => PlatformImpl?.GetRenderBounds(pen) ?? Rect.Empty;
 
         /// <summary>
         /// Indicates whether the geometry's fill contains the specified point.
@@ -102,7 +102,7 @@ namespace Avalonia.Media
         /// <param name="pen">The pen to use.</param>
         /// <param name="point">The point.</param>
         /// <returns><c>true</c> if the geometry contains the point; otherwise, <c>false</c>.</returns>
-        public bool StrokeContains(Pen pen, Point point)
+        public bool StrokeContains(IPen pen, Point point)
         {
             return PlatformImpl?.StrokeContains(pen, point) == true;
         }

src/Avalonia.Visuals/Media/GeometryDrawing.cs

@@ -1,12 +1,38 @@
-using Avalonia.Metadata;
+using Avalonia.Media.Immutable;
+using Avalonia.Metadata;
 
 namespace Avalonia.Media
 {
+    /// <summary>
+    /// Represents a drawing operation that combines 
+    /// a geometry with and brush and/or pen to produce rendered content.
+    /// </summary>
     public class GeometryDrawing : Drawing
     {
+        // Adding the Pen's stroke thickness here could yield wrong results due to transforms.
+        private static readonly IPen s_boundsPen = new ImmutablePen(Colors.Black.ToUint32(), 0);
+
+        /// <summary>
+        /// Defines the <see cref="Geometry"/> property.
+        /// </summary>
         public static readonly StyledProperty<Geometry> GeometryProperty =
             AvaloniaProperty.Register<GeometryDrawing, Geometry>(nameof(Geometry));
 
+        /// <summary>
+        /// Defines the <see cref="Brush"/> property.
+        /// </summary>
+        public static readonly StyledProperty<IBrush> BrushProperty =
+            AvaloniaProperty.Register<GeometryDrawing, IBrush>(nameof(Brush), Brushes.Transparent);
+
+        /// <summary>
+        /// Defines the <see cref="Pen"/> property.
+        /// </summary>
+        public static readonly StyledProperty<Pen> PenProperty =
+            AvaloniaProperty.Register<GeometryDrawing, Pen>(nameof(Pen));
+
+        /// <summary>
+        /// Gets or sets the <see cref="Avalonia.Media.Geometry"/> that describes the shape of this <see cref="GeometryDrawing"/>.
+        /// </summary>
         [Content]
         public Geometry Geometry
         {
@@ -14,18 +40,18 @@ namespace Avalonia.Media
             set => SetValue(GeometryProperty, value);
         }
 
-        public static readonly StyledProperty<IBrush> BrushProperty =
-            AvaloniaProperty.Register<GeometryDrawing, IBrush>(nameof(Brush), Brushes.Transparent);
-
+        /// <summary>
+        /// Gets or sets the <see cref="Avalonia.Media.IBrush"/> used to fill the interior of the shape described by this <see cref="GeometryDrawing"/>.
+        /// </summary>
         public IBrush Brush
         {
             get => GetValue(BrushProperty);
             set => SetValue(BrushProperty, value);
         }
 
-        public static readonly StyledProperty<Pen> PenProperty =
-            AvaloniaProperty.Register<GeometryDrawing, Pen>(nameof(Pen));
-
+        /// <summary>
+        /// Gets or sets the <see cref="Avalonia.Media.IPen"/> used to stroke this <see cref="GeometryDrawing"/>.
+        /// </summary>
         public IPen Pen
         {
             get => GetValue(PenProperty);
@@ -42,9 +68,7 @@ namespace Avalonia.Media
 
         public override Rect GetBounds()
         {
-            // adding the Pen's stroke thickness here could yield wrong results due to transforms
-            var pen = new Pen(Brushes.Black, 0);
-            return Geometry?.GetRenderBounds(pen) ?? new Rect();
+            return Geometry?.GetRenderBounds(s_boundsPen) ?? Rect.Empty;
         }
     }
 }