Refactored brushes.

`SolidColorBrush` is now mutable. There are immutable versions of
brushes in the `Avalona.Media.Immutable` namespace and the static
`Brushes.Xxx` properties return these.

src/Avalonia.Themes.Default/Accents/BaseLight.xaml

@@ -1,6 +1,5 @@
 <Style xmlns="https://github.com/avaloniaui"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-       xmlns:mut="https://github.com/avaloniaui/mutable"
        xmlns:sys="clr-namespace:System;assembly=mscorlib">
   <Style.Resources>
     <SolidColorBrush x:Key="ThemeBackgroundBrush">#FFFFFFFF</SolidColorBrush>

src/Avalonia.Visuals/Avalonia.Visuals.csproj

@@ -70,6 +70,9 @@
     <Compile Include="Media\Color.cs" />
     <Compile Include="Media\Colors.cs" />
     <Compile Include="Media\IImageBrush.cs" />
+    <Compile Include="Media\Immutable\ImmutableTileBrush.cs" />
+    <Compile Include="Media\Immutable\ImmutableSolidColorBrush.cs" />
+    <Compile Include="Media\IMutableBrush.cs" />
     <Compile Include="Media\ITileBrush.cs" />
     <Compile Include="Media\IVisualBrush.cs" />
     <Compile Include="Media\TextWrapping.cs" />
@@ -84,7 +87,6 @@
     <Compile Include="Media\ISolidColorBrush.cs" />
     <Compile Include="Media\LineGeometry.cs" />
     <Compile Include="Media\LineSegment.cs" />
-    <Compile Include="Media\Mutable\SolidColorBrush.cs" />
     <Compile Include="Media\PathGeometryCollections.cs" />
     <Compile Include="Media\PathFigure.cs" />
     <Compile Include="Media\PathGeometry.cs" />
@@ -134,8 +136,8 @@
     <Compile Include="Rendering\SceneGraph\ISceneBuilder.cs" />
     <Compile Include="Rendering\SceneGraph\IVisualNode.cs" />
     <Compile Include="Rendering\SceneGraph\LineNode.cs" />
-    <Compile Include="Rendering\SceneGraph\Media\SceneVisualBrush.cs" />
-    <Compile Include="Rendering\SceneGraph\Media\SceneImageBrush.cs" />
+    <Compile Include="Media\Immutable\ImmutableVisualBrush.cs" />
+    <Compile Include="Media\Immutable\ImmutableImageBrush.cs" />
     <Compile Include="Rendering\SceneGraph\RectangleNode.cs" />
     <Compile Include="Rendering\SceneGraph\Scene.cs" />
     <Compile Include="Rendering\SceneGraph\SceneBuilder.cs" />
@@ -211,6 +213,9 @@
       <Private>True</Private>
     </Reference>
   </ItemGroup>
+  <ItemGroup>
+    <Folder Include="Rendering\SceneGraph\Media\" />
+  </ItemGroup>
   <Import Project="$(MSBuildExtensionsPath32)\Microsoft\Portable\$(TargetFrameworkVersion)\Microsoft.Portable.CSharp.targets" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
        Other similar extension points exist, see Microsoft.Common.targets.

src/Avalonia.Visuals/Media/Brush.cs

@@ -46,7 +46,8 @@ namespace Avalonia.Media
 
                 if (member != null)
                 {
-                    return (IBrush)member.GetValue(null);
+                    var brush = (ISolidColorBrush)member.GetValue(null);
+                    return new SolidColorBrush(brush.Color, brush.Opacity);
                 }
                 else
                 {

src/Avalonia.Visuals/Media/IMutableBrush.cs

@@ -0,0 +1,16 @@
+using System;
+
+namespace Avalonia.Media
+{
+    /// <summary>
+    /// Represents a mutable brush which can return an immutable clone of itself.
+    /// </summary>
+    public interface IMutableBrush : IBrush
+    {
+        /// <summary>
+        /// Creates an immutable clone of the brush.
+        /// </summary>
+        /// <returns>The immutable clone.</returns>
+        IBrush ToImmutable();
+    }
+}

src/Avalonia.Visuals/Media/ImageBush.cs

@@ -8,7 +8,7 @@ namespace Avalonia.Media
     /// <summary>
     /// Paints an area with an <see cref="IBitmap"/>.
     /// </summary>
-    public class ImageBrush : TileBrush, IImageBrush
+    public class ImageBrush : TileBrush, IImageBrush, IMutableBrush
     {
         /// <summary>
         /// Defines the <see cref="Visual"/> property.
@@ -17,14 +17,14 @@ namespace Avalonia.Media
             AvaloniaProperty.Register<ImageBrush, IBitmap>("Source");
 
         /// <summary>
-        /// Initializes a new instance of the <see cref="VisualBrush"/> class.
+        /// Initializes a new instance of the <see cref="ImageBrush"/> class.
         /// </summary>
         public ImageBrush()
         {
         }
 
         /// <summary>
-        /// Initializes a new instance of the <see cref="VisualBrush"/> class.
+        /// Initializes a new instance of the <see cref="ImageBrush"/> class.
         /// </summary>
         /// <param name="source">The image to draw.</param>
         public ImageBrush(IBitmap source)
@@ -40,5 +40,11 @@ namespace Avalonia.Media
             get { return GetValue(SourceProperty); }
             set { SetValue(SourceProperty, value); }
         }
+
+        /// <inheritdoc/>
+        IBrush IMutableBrush.ToImmutable()
+        {
+            return new Immutable.ImmutableImageBrush(this);
+        }
     }
 }

src/Avalonia.Visuals/Media/Immutable/ImmutableImageBrush.cs

@@ -0,0 +1,58 @@
+using System;
+using Avalonia.Media.Imaging;
+
+namespace Avalonia.Media.Immutable
+{
+    /// <summary>
+    /// Paints an area with an <see cref="IBitmap"/>.
+    /// </summary>
+    internal class ImmutableImageBrush : ImmutableTileBrush, IImageBrush
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ImmutableImageBrush"/> class.
+        /// </summary>
+        /// <param name="source">The image to draw.</param>
+        /// <param name="alignmentX">The horizontal alignment of a tile in the destination.</param>
+        /// <param name="alignmentY">The vertical alignment of a tile in the destination.</param>
+        /// <param name="destinationRect">The rectangle on the destination in which to paint a tile.</param>
+        /// <param name="opacity">The opacity of the brush.</param>
+        /// <param name="sourceRect">The rectangle of the source image that will be displayed.</param>
+        /// <param name="stretch">
+        /// How the source rectangle will be stretched to fill the destination rect.
+        /// </param>
+        /// <param name="tileMode">The tile mode.</param>
+        public ImmutableImageBrush(
+            IBitmap source,
+            AlignmentX alignmentX = AlignmentX.Center,
+            AlignmentY alignmentY = AlignmentY.Center,
+            RelativeRect? destinationRect = null,
+            double opacity = 1,
+            RelativeRect? sourceRect = null,
+            Stretch stretch = Stretch.Uniform,
+            TileMode tileMode = TileMode.None)
+            : base(
+                  alignmentX,
+                  alignmentY,
+                  destinationRect ?? RelativeRect.Fill,
+                  opacity,
+                  sourceRect ?? RelativeRect.Fill,
+                  stretch,
+                  tileMode)
+        {
+            Source = source;
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ImmutableImageBrush"/> class.
+        /// </summary>
+        /// <param name="source">The brush from which this brush's properties should be copied.</param>
+        public ImmutableImageBrush(IImageBrush source)
+            : base(source)
+        {
+            Source = source.Source;
+        }
+
+        /// <inheritdoc/>
+        public IBitmap Source { get; }
+    }
+}

src/Avalonia.Visuals/Media/Immutable/ImmutableSolidColorBrush.cs

@@ -0,0 +1,59 @@
+// Copyright (c) The Avalonia Project. All rights reserved.
+// Licensed under the MIT license. See licence.md file in the project root for full license information.
+
+namespace Avalonia.Media.Immutable
+{
+    /// <summary>
+    /// Fills an area with a solid color.
+    /// </summary>
+    public struct ImmutableSolidColorBrush : ISolidColorBrush
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ImmutableSolidColorBrush"/> class.
+        /// </summary>
+        /// <param name="color">The color to use.</param>
+        /// <param name="opacity">The opacity of the brush.</param>
+        public ImmutableSolidColorBrush(Color color, double opacity = 1)
+        {
+            Color = color;
+            Opacity = opacity;
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ImmutableSolidColorBrush"/> class.
+        /// </summary>
+        /// <param name="color">The color to use.</param>
+        public ImmutableSolidColorBrush(uint color)
+            : this(Color.FromUInt32(color))
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ImmutableSolidColorBrush"/> class.
+        /// </summary>
+        /// <param name="source">The brush from which this brush's properties should be copied.</param>
+        public ImmutableSolidColorBrush(ISolidColorBrush source)
+            : this(source.Color, source.Opacity)
+        {
+        }
+
+        /// <summary>
+        /// Gets the color of the brush.
+        /// </summary>
+        public Color Color { get; }
+
+        /// <summary>
+        /// Gets the opacity of the brush.
+        /// </summary>
+        public double Opacity { get; }
+
+        /// <summary>
+        /// Returns a string representation of the brush.
+        /// </summary>
+        /// <returns>A string representation of the brush.</returns>
+        public override string ToString()
+        {
+            return Color.ToString();
+        }
+    }
+}

src/Avalonia.Visuals/Media/Immutable/ImmutableTileBrush.cs

@@ -0,0 +1,77 @@
+using System;
+
+namespace Avalonia.Media.Immutable
+{
+    /// <summary>
+    /// A brush which displays a repeating image.
+    /// </summary>
+    public abstract class ImmutableTileBrush : ITileBrush
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ImageBrush"/> class.
+        /// </summary>
+        /// <param name="alignmentX">The horizontal alignment of a tile in the destination.</param>
+        /// <param name="alignmentY">The vertical alignment of a tile in the destination.</param>
+        /// <param name="destinationRect">The rectangle on the destination in which to paint a tile.</param>
+        /// <param name="opacity">The opacity of the brush.</param>
+        /// <param name="sourceRect">The rectangle of the source image that will be displayed.</param>
+        /// <param name="stretch">
+        /// How the source rectangle will be stretched to fill the destination rect.
+        /// </param>
+        /// <param name="tileMode">The tile mode.</param>
+        protected ImmutableTileBrush(
+            AlignmentX alignmentX,
+            AlignmentY alignmentY,
+            RelativeRect destinationRect,
+            double opacity,
+            RelativeRect sourceRect,
+            Stretch stretch,
+            TileMode tileMode)
+        {
+            AlignmentX = alignmentX;
+            AlignmentY = alignmentY;
+            DestinationRect = destinationRect;
+            Opacity = opacity;
+            SourceRect = sourceRect;
+            Stretch = stretch;
+            TileMode = tileMode;
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ImageBrush"/> class.
+        /// </summary>
+        /// <param name="source">The brush from which this brush's properties should be copied.</param>
+        protected ImmutableTileBrush(ITileBrush source)
+            : this(
+                  source.AlignmentX,
+                  source.AlignmentY,
+                  source.DestinationRect,
+                  source.Opacity,
+                  source.SourceRect,
+                  source.Stretch,
+                  source.TileMode)
+        {
+        }
+
+        /// <inheritdoc/>
+        public AlignmentX AlignmentX { get; }
+
+        /// <inheritdoc/>
+        public AlignmentY AlignmentY { get; }
+
+        /// <inheritdoc/>
+        public RelativeRect DestinationRect { get; }
+
+        /// <inheritdoc/>
+        public double Opacity { get; }
+
+        /// <inheritdoc/>
+        public RelativeRect SourceRect { get; }
+
+        /// <inheritdoc/>
+        public Stretch Stretch { get; }
+
+        /// <inheritdoc/>
+        public TileMode TileMode { get; }
+    }
+}

src/Avalonia.Visuals/Media/Immutable/ImmutableVisualBrush.cs

@@ -0,0 +1,58 @@
+using System;
+using Avalonia.VisualTree;
+
+namespace Avalonia.Media.Immutable
+{
+    /// <summary>
+    /// Paints an area with an <see cref="IVisual"/>.
+    /// </summary>
+    internal class ImmutableVisualBrush : ImmutableTileBrush, IVisualBrush
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ImmutableImageBrush"/> class.
+        /// </summary>
+        /// <param name="visual">The visual to draw.</param>
+        /// <param name="alignmentX">The horizontal alignment of a tile in the destination.</param>
+        /// <param name="alignmentY">The vertical alignment of a tile in the destination.</param>
+        /// <param name="destinationRect">The rectangle on the destination in which to paint a tile.</param>
+        /// <param name="opacity">The opacity of the brush.</param>
+        /// <param name="sourceRect">The rectangle of the source image that will be displayed.</param>
+        /// <param name="stretch">
+        /// How the source rectangle will be stretched to fill the destination rect.
+        /// </param>
+        /// <param name="tileMode">The tile mode.</param>
+        public ImmutableVisualBrush(
+            IVisual visual,
+            AlignmentX alignmentX = AlignmentX.Center,
+            AlignmentY alignmentY = AlignmentY.Center,
+            RelativeRect? destinationRect = null,
+            double opacity = 1,
+            RelativeRect? sourceRect = null,
+            Stretch stretch = Stretch.Uniform,
+            TileMode tileMode = TileMode.None)
+            : base(
+                  alignmentX,
+                  alignmentY,
+                  destinationRect ?? RelativeRect.Fill,
+                  opacity,
+                  sourceRect ?? RelativeRect.Fill,
+                  stretch,
+                  tileMode)
+        {
+            Visual = visual;
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ImmutableVisualBrush"/> class.
+        /// </summary>
+        /// <param name="source">The brush from which this brush's properties should be copied.</param>
+        public ImmutableVisualBrush(IVisualBrush source)
+            : base(source)
+        {
+            Visual = source.Visual;
+        }
+
+        /// <inheritdoc/>
+        public IVisual Visual { get; }
+    }
+}

src/Avalonia.Visuals/Media/Mutable/SolidColorBrush.cs

@@ -1,35 +0,0 @@
-// Copyright (c) The Avalonia Project. All rights reserved.
-// Licensed under the MIT license. See licence.md file in the project root for full license information.
-
-namespace Avalonia.Media.Mutable
-{
-    /// <summary>
-    /// Fills an area with a solid color.
-    /// </summary>
-    /// <remarks>
-    /// This is a mutable version of the normal immutable <see cref="Avalonia.Media.SolidColorBrush"/>
-    /// for use in XAML. XAML really needs support for immutable data...
-    /// </remarks>
-    public class SolidColorBrush : Brush, ISolidColorBrush
-    {
-        public static readonly DirectProperty<SolidColorBrush, Color> ColorProperty =
-            AvaloniaProperty.RegisterDirect<SolidColorBrush, Color>(
-                "Color",
-                o => o.Color,
-                (o, v) => o.Color = v);
-
-        /// <summary>
-        /// Gets the color of the brush.
-        /// </summary>
-        public Color Color { get; set; }
-
-        /// <summary>
-        /// Returns a string representation of the brush.
-        /// </summary>
-        /// <returns>A string representation of the brush.</returns>
-        public override string ToString()
-        {
-            return Color.ToString();
-        }
-    }
-}

src/Avalonia.Visuals/Media/SolidColorBrush.cs

@@ -1,13 +1,28 @@
 // Copyright (c) The Avalonia Project. All rights reserved.
 // Licensed under the MIT license. See licence.md file in the project root for full license information.
 
+using System;
+
 namespace Avalonia.Media
 {
     /// <summary>
     /// Fills an area with a solid color.
     /// </summary>
-    public class SolidColorBrush : ISolidColorBrush
+    public class SolidColorBrush : Brush, ISolidColorBrush, IMutableBrush
     {
+        /// <summary>
+        /// Defines the <see cref="Color"/> property.
+        /// </summary>
+        public static readonly StyledProperty<Color> ColorProperty =
+            AvaloniaProperty.Register<SolidColorBrush, Color>(nameof(Color));
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="SolidColorBrush"/> class.
+        /// </summary>
+        public SolidColorBrush()
+        {
+        }
+
         /// <summary>
         /// Initializes a new instance of the <see cref="SolidColorBrush"/> class.
         /// </summary>
@@ -29,14 +44,13 @@ namespace Avalonia.Media
         }
 
         /// <summary>
-        /// Gets the color of the brush.
+        /// Gets or sets the color of the brush.
         /// </summary>
-        public Color Color { get; }
-
-        /// <summary>
-        /// Gets the opacity of the brush.
-        /// </summary>
-        public double Opacity { get; }
+        public Color Color
+        {
+            get { return GetValue(ColorProperty); }
+            set { SetValue(ColorProperty, value); }
+        }
 
         /// <summary>
         /// Returns a string representation of the brush.
@@ -46,5 +60,11 @@ namespace Avalonia.Media
         {
             return Color.ToString();
         }
+
+        /// <inheritdoc/>
+        IBrush IMutableBrush.ToImmutable()
+        {
+            return new Immutable.ImmutableSolidColorBrush(this);
+        }
     }
 }

src/Avalonia.Visuals/Media/VisualBrush.cs

@@ -8,7 +8,7 @@ namespace Avalonia.Media
     /// <summary>
     /// Paints an area with an <see cref="IVisual"/>.
     /// </summary>
-    public class VisualBrush : TileBrush, IVisualBrush
+    public class VisualBrush : TileBrush, IVisualBrush, IMutableBrush
     {
         /// <summary>
         /// Defines the <see cref="Visual"/> property.
@@ -40,5 +40,11 @@ namespace Avalonia.Media
             get { return GetValue(VisualProperty); }
             set { SetValue(VisualProperty, value); }
         }
+
+        /// <inheritdoc/>
+        IBrush IMutableBrush.ToImmutable()
+        {
+            return new Immutable.ImmutableVisualBrush(this);
+        }
     }
 }

src/Avalonia.Visuals/Rendering/DeferredRenderer.cs

@@ -10,6 +10,7 @@ using Avalonia.Threading;
 using Avalonia.VisualTree;
 using System.Collections.Generic;
 using System.IO;
+using Avalonia.Media.Immutable;
 
 namespace Avalonia.Rendering
 {
@@ -239,7 +240,7 @@ namespace Avalonia.Rendering
         {
             foreach (var r in _dirtyRectsDisplay)
             {
-                var brush = new SolidColorBrush(Colors.Magenta, r.Opacity);
+                var brush = new ImmutableSolidColorBrush(Colors.Magenta, r.Opacity);
                 context.FillRectangle(brush, r.Rect);
             }
         }

src/Avalonia.Visuals/Rendering/SceneGraph/BrushDrawOperation.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Collections.Generic;
 using Avalonia.Media;
-using Avalonia.Rendering.SceneGraph.Media;
+using Avalonia.Media.Immutable;
 using Avalonia.VisualTree;
 
 namespace Avalonia.Rendering.SceneGraph
@@ -14,32 +14,18 @@ namespace Avalonia.Rendering.SceneGraph
 
         public abstract void Render(IDrawingContextImpl context);
 
-        protected IBrush Convert(IBrush brush)
+        protected IBrush ToImmutable(IBrush brush)
         {
-            var imageBrush = brush as ImageBrush;
-            var visualBrush = brush as VisualBrush;
-            
-            if (imageBrush != null)
-            {
-                return new SceneImageBrush(imageBrush);
-            }
-            else if (visualBrush != null)
-            {
-                return new SceneVisualBrush(visualBrush);
-            }
-            else
-            {
-                return brush;
-            }
+            return (brush as IMutableBrush)?.ToImmutable() ?? brush;
         }
 
-        protected Pen Convert(Pen pen)
+        protected Pen ToImmutable(Pen pen)
         {
-            var brush = pen?.Brush != null ? Convert(pen.Brush) : null;
+            var brush = pen?.Brush != null ? ToImmutable(pen.Brush) : null;
             return ReferenceEquals(pen?.Brush, brush) ?
                 pen :
                 new Pen(
-                    pen.Brush,
+                    brush,
                     thickness: pen.Thickness,
                     dashStyle: pen.DashStyle,
                     dashCap: pen.DashCap,

src/Avalonia.Visuals/Rendering/SceneGraph/GeometryNode.cs

@@ -20,8 +20,8 @@ namespace Avalonia.Rendering.SceneGraph
         {
             Bounds = geometry.GetRenderBounds(pen.Thickness).TransformToAABB(transform);
             Transform = transform;
-            Brush = Convert(brush);
-            Pen = Convert(pen);
+            Brush = ToImmutable(brush);
+            Pen = ToImmutable(pen);
             Geometry = geometry;
             ChildScenes = childScenes;
         }

src/Avalonia.Visuals/Rendering/SceneGraph/LineNode.cs

@@ -14,7 +14,7 @@ namespace Avalonia.Rendering.SceneGraph
         {
             Bounds = new Rect(P1, P2);
             Transform = transform;
-            Pen = Convert(pen);
+            Pen = ToImmutable(pen);
             P1 = p1;
             P2 = p2;
         }

src/Avalonia.Visuals/Rendering/SceneGraph/Media/SceneImageBrush.cs

@@ -1,37 +0,0 @@
-using System;
-using Avalonia.Media;
-using Avalonia.Media.Imaging;
-
-namespace Avalonia.Rendering.SceneGraph.Media
-{
-    internal class SceneImageBrush : IImageBrush
-    {
-        public SceneImageBrush(IImageBrush source)
-        {
-            AlignmentX = source.AlignmentX;
-            AlignmentY = source.AlignmentY;
-            DestinationRect = source.DestinationRect;
-            Opacity = source.Opacity;
-            Source = source.Source;
-            SourceRect = source.SourceRect;
-            Stretch = source.Stretch;
-            TileMode = source.TileMode;
-        }
-
-        public AlignmentX AlignmentX { get; }
-
-        public AlignmentY AlignmentY { get; }
-
-        public RelativeRect DestinationRect { get; }
-
-        public double Opacity { get; }
-
-        public IBitmap Source { get; }
-
-        public RelativeRect SourceRect { get; }
-
-        public Stretch Stretch { get; }
-
-        public TileMode TileMode { get; }
-    }
-}

src/Avalonia.Visuals/Rendering/SceneGraph/Media/SceneVisualBrush.cs

@@ -1,37 +0,0 @@
-using System;
-using Avalonia.Media;
-using Avalonia.VisualTree;
-
-namespace Avalonia.Rendering.SceneGraph.Media
-{
-    internal class SceneVisualBrush : IVisualBrush
-    {
-        public SceneVisualBrush(IVisualBrush source)
-        {
-            AlignmentX = source.AlignmentX;
-            AlignmentY = source.AlignmentY;
-            DestinationRect = source.DestinationRect;
-            Opacity = source.Opacity;
-            SourceRect = source.SourceRect;
-            Stretch = source.Stretch;
-            TileMode = source.TileMode;
-            Visual = source.Visual;
-        }
-
-        public AlignmentX AlignmentX { get; }
-
-        public AlignmentY AlignmentY { get; }
-
-        public RelativeRect DestinationRect { get; }
-
-        public double Opacity { get; }
-
-        public RelativeRect SourceRect { get; }
-
-        public Stretch Stretch { get; }
-
-        public TileMode TileMode { get; }
-
-        public IVisual Visual { get; }
-    }
-}

src/Avalonia.Visuals/Rendering/SceneGraph/RectangleNode.cs

@@ -20,8 +20,8 @@ namespace Avalonia.Rendering.SceneGraph
         {
             Bounds = rect.TransformToAABB(transform).Inflate(pen?.Thickness ?? 0);
             Transform = transform;
-            Brush = Convert(brush);
-            Pen = Convert(pen);
+            Brush = ToImmutable(brush);
+            Pen = ToImmutable(pen);
             Rect = rect;
             CornerRadius = cornerRadius;
             ChildScenes = childScenes;

src/Avalonia.Visuals/Rendering/SceneGraph/TextNode.cs

@@ -9,25 +9,25 @@ using Avalonia.VisualTree;
 
 namespace Avalonia.Rendering.SceneGraph
 {
-    internal class TextNode : IDrawOperation
+    internal class TextNode : BrushDrawOperation
     {
         public TextNode(Matrix transform, IBrush foreground, Point origin, IFormattedTextImpl text)
         {
             Bounds = new Rect(origin, text.Size).TransformToAABB(transform);
             Transform = transform;
-            Foreground = foreground;
+            Foreground = ToImmutable(foreground);
             Origin = origin;
             Text = text;
         }
 
-        public Rect Bounds { get; }
+        public override Rect Bounds { get; }
         public Matrix Transform { get; }
         public IBrush Foreground { get; }
         public Point Origin { get; }
         public IFormattedTextImpl Text { get; }
-        public IDictionary<VisualBrush, Scene> ChildScenes => null;
+        public override IDictionary<IVisual, Scene> ChildScenes => null;
 
-        public void Render(IDrawingContextImpl context)
+        public override void Render(IDrawingContextImpl context)
         {
             context.Transform = Transform;
             context.DrawText(Foreground, Origin, Text);
@@ -41,6 +41,6 @@ namespace Avalonia.Rendering.SceneGraph
                 Equals(text, Text);
         }
 
-        public bool HitTest(Point p) => Bounds.Contains(p);
+        public override bool HitTest(Point p) => Bounds.Contains(p);
     }
 }

tests/Avalonia.Markup.Xaml.UnitTests/Xaml/Style2.xaml

@@ -1,9 +1,8 @@
 <Style xmlns="https://github.com/avaloniaui"
-       xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-       xmlns:mut="https://github.com/avaloniaui/mutable">
+       xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
   <Style.Resources>
-    <mut:SolidColorBrush x:Key="RedBrush" Color="{StyleResource Red}"/>
-    <mut:SolidColorBrush x:Key="GreenBrush" Color="{StyleResource Green}"/>
-    <mut:SolidColorBrush x:Key="BlueBrush" Color="{StyleResource Blue}"/>
+    <SolidColorBrush x:Key="RedBrush" Color="{StyleResource Red}"/>
+    <SolidColorBrush x:Key="GreenBrush" Color="{StyleResource Green}"/>
+    <SolidColorBrush x:Key="BlueBrush" Color="{StyleResource Blue}"/>
   </Style.Resources>
 </Style>

tests/Avalonia.Markup.Xaml.UnitTests/Xaml/StyleTests.cs

@@ -124,13 +124,12 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
             {
                 var xaml = @"
 <Window xmlns='https://github.com/avaloniaui'
-        xmlns:mut='https://github.com/avaloniaui/mutable'
         xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
     <Window.Styles>
         <Style>
             <Style.Resources>
                 <Color x:Key='color'>#ff506070</Color>
-                <mut:SolidColorBrush x:Key='brush' Color='{StyleResource color}'/>
+                <SolidColorBrush x:Key='brush' Color='{StyleResource color}'/>
             </Style.Resources>
         </Style>
     </Window.Styles>
@@ -139,12 +138,12 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
 
                 var loader = new AvaloniaXamlLoader();
                 var window = (Window)loader.Load(xaml);
-                var brush = (Avalonia.Media.Mutable.SolidColorBrush)window.FindStyleResource("brush");
+                var brush = (Avalonia.Media.ISolidColorBrush)window.FindStyleResource("brush");
                 var button = window.FindControl<Button>("button");
 
                 DelayedBinding.ApplyBindings(button);
 
-                var buttonBrush = (Avalonia.Media.Mutable.SolidColorBrush)button.Background;
+                var buttonBrush = (Avalonia.Media.ISolidColorBrush)button.Background;
 
                 Assert.Equal(0xff506070, brush.Color.ToUint32());
                 Assert.Equal(0xff506070, buttonBrush.Color.ToUint32());
@@ -156,19 +155,18 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
         {
             var xaml = @"
 <Styles xmlns='https://github.com/avaloniaui'
-        xmlns:mut='https://github.com/avaloniaui/mutable'
         xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
     <Style>
         <Style.Resources>
             <Color x:Key='color'>#ff506070</Color>
-            <mut:SolidColorBrush x:Key='brush' Color='{StyleResource color}'/>
+            <SolidColorBrush x:Key='brush' Color='{StyleResource color}'/>
         </Style.Resources>
     </Style>
 </Styles>";
 
             var loader = new AvaloniaXamlLoader();
             var styles = (Styles)loader.Load(xaml);
-            var brush = (Avalonia.Media.Mutable.SolidColorBrush)styles.FindResource("brush");
+            var brush = (Avalonia.Media.ISolidColorBrush)styles.FindResource("brush");
 
             Assert.Equal(0xff506070, brush.Color.ToUint32());
         }
@@ -178,7 +176,6 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
         {
             var xaml = @"
 <Styles xmlns='https://github.com/avaloniaui'
-        xmlns:mut='https://github.com/avaloniaui/mutable'
         xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
     <Style>
         <Style.Resources>
@@ -187,14 +184,14 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
     </Style>
     <Style>
         <Style.Resources>
-            <mut:SolidColorBrush x:Key='brush' Color='{StyleResource color}'/>
+            <SolidColorBrush x:Key='brush' Color='{StyleResource color}'/>
         </Style.Resources>
     </Style>
 </Styles>";
 
             var loader = new AvaloniaXamlLoader();
             var styles = (Styles)loader.Load(xaml);
-            var brush = (Avalonia.Media.Mutable.SolidColorBrush)styles.FindResource("brush");
+            var brush = (Avalonia.Media.ISolidColorBrush)styles.FindResource("brush");
 
             Assert.Equal(0xff506070, brush.Color.ToUint32());
         }
@@ -206,7 +203,6 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
             {
                 var xaml = @"
 <Window xmlns='https://github.com/avaloniaui'
-        xmlns:mut='https://github.com/avaloniaui/mutable'
         xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
     <Window.Styles>
         <StyleInclude Source='resm:Avalonia.Markup.Xaml.UnitTests.Xaml.Style1.xaml?assembly=Avalonia.Markup.Xaml.UnitTests'/>
@@ -218,7 +214,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
                 var loader = new AvaloniaXamlLoader();
                 var window = (Window)loader.Load(xaml);
                 var border = window.FindControl<Border>("border");
-                var borderBrush = (Avalonia.Media.Mutable.SolidColorBrush)border.Background;
+                var borderBrush = (Avalonia.Media.ISolidColorBrush)border.Background;
 
                 Assert.NotNull(borderBrush);
                 Assert.Equal(0xffff0000, borderBrush.Color.ToUint32());

tests/Avalonia.RenderTests/Avalonia.Cairo.RenderTests.v3.ncrunchproject

@@ -0,0 +1,76 @@
+<ProjectConfiguration>
+  <Settings>
+    <HiddenComponentWarnings>
+      <Value>AbnormalReferenceResolution</Value>
+    </HiddenComponentWarnings>
+    <IgnoredTests>
+      <FixtureTestSelector>
+        <FixtureName>Avalonia.Cairo.RenderTests.Controls.BorderTests</FixtureName>
+      </FixtureTestSelector>
+      <NamedTestSelector>
+        <TestName>Avalonia.Cairo.RenderTests.Media.ImageBrushTests.ImageBrush_Fill_NoTile</TestName>
+      </NamedTestSelector>
+      <NamedTestSelector>
+        <TestName>Avalonia.Cairo.RenderTests.Media.ImageBrushTests.ImageBrush_NoStretch_FlipXY_TopLeftDest</TestName>
+      </NamedTestSelector>
+      <NamedTestSelector>
+        <TestName>Avalonia.Cairo.RenderTests.Media.ImageBrushTests.ImageBrush_NoStretch_NoTile_Alignment_BottomRight</TestName>
+      </NamedTestSelector>
+      <NamedTestSelector>
+        <TestName>Avalonia.Cairo.RenderTests.Media.ImageBrushTests.ImageBrush_NoStretch_NoTile_Alignment_Center</TestName>
+      </NamedTestSelector>
+      <NamedTestSelector>
+        <TestName>Avalonia.Cairo.RenderTests.Media.ImageBrushTests.ImageBrush_NoStretch_NoTile_BottomRightQuarterDest</TestName>
+      </NamedTestSelector>
+      <NamedTestSelector>
+        <TestName>Avalonia.Cairo.RenderTests.Media.ImageBrushTests.ImageBrush_NoStretch_NoTile_BottomRightQuarterSource</TestName>
+      </NamedTestSelector>
+      <NamedTestSelector>
+        <TestName>Avalonia.Cairo.RenderTests.Media.ImageBrushTests.ImageBrush_NoStretch_NoTile_BottomRightQuarterSource_BottomRightQuarterDest</TestName>
+      </NamedTestSelector>
+      <NamedTestSelector>
+        <TestName>Avalonia.Cairo.RenderTests.Media.ImageBrushTests.ImageBrush_NoStretch_Tile_BottomRightQuarterSource_CenterQuarterDest</TestName>
+      </NamedTestSelector>
+      <NamedTestSelector>
+        <TestName>Avalonia.Cairo.RenderTests.Media.ImageBrushTests.ImageBrush_Uniform_NoTile</TestName>
+      </NamedTestSelector>
+      <NamedTestSelector>
+        <TestName>Avalonia.Cairo.RenderTests.Media.ImageBrushTests.ImageBrush_UniformToFill_NoTile</TestName>
+      </NamedTestSelector>
+      <FixtureTestSelector>
+        <FixtureName>Avalonia.Cairo.RenderTests.Controls.ImageTests</FixtureName>
+      </FixtureTestSelector>
+      <FixtureTestSelector>
+        <FixtureName>Avalonia.Cairo.RenderTests.GeometryClippingTests</FixtureName>
+      </FixtureTestSelector>
+      <NamedTestSelector>
+        <TestName>Avalonia.Cairo.RenderTests.Media.LinearGradientBrushTests.LinearGradientBrush_RedBlue_Vertical_Fill</TestName>
+      </NamedTestSelector>
+      <FixtureTestSelector>
+        <FixtureName>Avalonia.Cairo.RenderTests.Media.VisualBrushTests</FixtureName>
+      </FixtureTestSelector>
+      <FixtureTestSelector>
+        <FixtureName>Avalonia.Cairo.RenderTests.OpacityMaskTests</FixtureName>
+      </FixtureTestSelector>
+      <FixtureTestSelector>
+        <FixtureName>Avalonia.Cairo.RenderTests.Shapes.EllipseTests</FixtureName>
+      </FixtureTestSelector>
+      <FixtureTestSelector>
+        <FixtureName>Avalonia.Cairo.RenderTests.Shapes.LineTests</FixtureName>
+      </FixtureTestSelector>
+      <FixtureTestSelector>
+        <FixtureName>Avalonia.Cairo.RenderTests.Shapes.PathTests</FixtureName>
+      </FixtureTestSelector>
+      <FixtureTestSelector>
+        <FixtureName>Avalonia.Cairo.RenderTests.Shapes.RectangleTests</FixtureName>
+      </FixtureTestSelector>
+      <NamedTestSelector>
+        <TestName>Avalonia.Cairo.RenderTests.Media.ImageBrushTests.ImageBrush_NoStretch_NoTile_Alignment_TopLeft</TestName>
+      </NamedTestSelector>
+      <NamedTestSelector>
+        <TestName>Avalonia.Cairo.RenderTests.Media.LinearGradientBrushTests.LinearGradientBrush_RedBlue_Horizontal_Fill</TestName>
+      </NamedTestSelector>
+    </IgnoredTests>
+    <PreviouslyBuiltSuccessfully>True</PreviouslyBuiltSuccessfully>
+  </Settings>
+</ProjectConfiguration>

tests/Avalonia.RenderTests/Avalonia.Direct2D1.RenderTests.v3.ncrunchproject

@@ -2,9 +2,9 @@
   <Settings>
     <DefaultTestTimeout>1000</DefaultTestTimeout>
     <IgnoredTests>
-      <FixtureTestSelector>
-        <FixtureName>Avalonia.Direct2D1.RenderTests.Media.LinearGradientBrushTests</FixtureName>
-      </FixtureTestSelector>
+      <NamedTestSelector>
+        <TestName>Avalonia.Direct2D1.RenderTests.Media.LinearGradientBrushTests.LinearGradientBrush_RedBlue_Vertical_Fill</TestName>
+      </NamedTestSelector>
       <FixtureTestSelector>
         <FixtureName>Avalonia.Direct2D1.RenderTests.Controls.BorderTests</FixtureName>
       </FixtureTestSelector>
@@ -38,6 +38,9 @@
       <FixtureTestSelector>
         <FixtureName>Avalonia.Direct2D1.RenderTests.Shapes.RectangleTests</FixtureName>
       </FixtureTestSelector>
+      <NamedTestSelector>
+        <TestName>Avalonia.Direct2D1.RenderTests.Media.LinearGradientBrushTests.LinearGradientBrush_RedBlue_Horizontal_Fill</TestName>
+      </NamedTestSelector>
     </IgnoredTests>
     <PreviouslyBuiltSuccessfully>True</PreviouslyBuiltSuccessfully>
   </Settings>