Added IImageBrush and IVisualBrush

And make an immutable `SceneImageBrush` and `SceneVisualBrush` which
clone the mutable `ImageBrush` and `VisualBrush` for use in the scene
graph, as we shouldn't be accessing mutable state from the render
thread.

src/Avalonia.Visuals/Avalonia.Visuals.csproj

@@ -69,6 +69,9 @@
     <Compile Include="Media\BrushMappingMode.cs" />
     <Compile Include="Media\Color.cs" />
     <Compile Include="Media\Colors.cs" />
+    <Compile Include="Media\IImageBrush.cs" />
+    <Compile Include="Media\ITileBrush.cs" />
+    <Compile Include="Media\IVisualBrush.cs" />
     <Compile Include="Media\TextWrapping.cs" />
     <Compile Include="Media\TransformGroup.cs" />
     <Compile Include="Media\DashStyle.cs" />
@@ -124,12 +127,15 @@
     <Compile Include="Rendering\RenderLayer.cs" />
     <Compile Include="Rendering\RenderLayers.cs" />
     <Compile Include="Rendering\SceneGraph\DeferredDrawingContextImpl.cs" />
+    <Compile Include="Rendering\SceneGraph\BrushDrawOperation.cs" />
     <Compile Include="Rendering\SceneGraph\GeometryNode.cs" />
     <Compile Include="Rendering\SceneGraph\IDrawOperation.cs" />
     <Compile Include="Rendering\SceneGraph\ImageNode.cs" />
     <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="Rendering\SceneGraph\RectangleNode.cs" />
     <Compile Include="Rendering\SceneGraph\Scene.cs" />
     <Compile Include="Rendering\SceneGraph\SceneBuilder.cs" />
@@ -185,6 +191,7 @@
     <Compile Include="VisualTree\VisualExtensions.cs" />
   </ItemGroup>
   <ItemGroup>
+    <None Include="ClassDiagram1.cd" />
     <None Include="packages.config" />
   </ItemGroup>
   <ItemGroup>

src/Avalonia.Visuals/Media/IImageBrush.cs

@@ -0,0 +1,15 @@
+using Avalonia.Media.Imaging;
+
+namespace Avalonia.Media
+{
+    /// <summary>
+    /// Paints an area with an <see cref="IBitmap"/>.
+    /// </summary>
+    public interface IImageBrush : ITileBrush
+    {
+        /// <summary>
+        /// Gets the image to draw.
+        /// </summary>
+        IBitmap Source { get; }
+    }
+}

src/Avalonia.Visuals/Media/ITileBrush.cs

@@ -0,0 +1,39 @@
+namespace Avalonia.Media
+{
+    /// <summary>
+    /// A brush which displays a repeating image.
+    /// </summary>
+    public interface ITileBrush : IBrush
+    {
+        /// <summary>
+        /// Gets the horizontal alignment of a tile in the destination.
+        /// </summary>
+        AlignmentX AlignmentX { get; }
+
+        /// <summary>
+        /// Gets the horizontal alignment of a tile in the destination.
+        /// </summary>
+        AlignmentY AlignmentY { get; }
+
+        /// <summary>
+        /// Gets the rectangle on the destination in which to paint a tile.
+        /// </summary>
+        RelativeRect DestinationRect { get; }
+
+        /// <summary>
+        /// Gets the rectangle of the source image that will be displayed.
+        /// </summary>
+        RelativeRect SourceRect { get; }
+
+        /// <summary>
+        /// Gets a value indicating how the source rectangle will be stretched to fill the
+        /// destination rect.
+        /// </summary>
+        Stretch Stretch { get; }
+
+        /// <summary>
+        /// Gets the brush's tile mode.
+        /// </summary>
+        TileMode TileMode { get; }
+    }
+}

src/Avalonia.Visuals/Media/IVisualBrush.cs

@@ -0,0 +1,15 @@
+using Avalonia.VisualTree;
+
+namespace Avalonia.Media
+{
+    /// <summary>
+    /// Paints an area with an <see cref="IVisual"/>.
+    /// </summary>
+    public interface IVisualBrush : ITileBrush
+    {
+        /// <summary>
+        /// Gets the visual to draw.
+        /// </summary>
+        IVisual Visual { get; }
+    }
+}

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
+    public class ImageBrush : TileBrush, IImageBrush
     {
         /// <summary>
         /// Defines the <see cref="Visual"/> property.

src/Avalonia.Visuals/Media/TileBrush.cs

@@ -37,7 +37,7 @@ namespace Avalonia.Media
     /// <summary>
     /// Base class for brushes which display repeating images.
     /// </summary>
-    public abstract class TileBrush : Brush
+    public abstract class TileBrush : Brush, ITileBrush
     {
         /// <summary>
         /// Defines the <see cref="AlignmentX"/> property.

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
+    public class VisualBrush : TileBrush, IVisualBrush
     {
         /// <summary>
         /// Defines the <see cref="Visual"/> property.

src/Avalonia.Visuals/Rendering/DeferredRenderer.cs

@@ -105,7 +105,7 @@ namespace Avalonia.Rendering
             Render(_scene);
         }
 
-        Size IVisualBrushRenderer.GetRenderTargetSize(VisualBrush brush)
+        Size IVisualBrushRenderer.GetRenderTargetSize(IVisualBrush brush)
         {
             if (brush.Visual != null)
             {
@@ -115,7 +115,7 @@ namespace Avalonia.Rendering
             return Size.Empty;
         }
 
-        void IVisualBrushRenderer.RenderVisualBrush(IDrawingContextImpl context, VisualBrush brush)
+        void IVisualBrushRenderer.RenderVisualBrush(IDrawingContextImpl context, IVisualBrush brush)
         {
             if (brush.Visual != null)
             {

src/Avalonia.Visuals/Rendering/IVisualBrushRenderer.cs

@@ -17,7 +17,7 @@ namespace Avalonia.Rendering
         /// </summary>
         /// <param name="brush">The visual brush.</param>
         /// <returns>The size of the intermediate render target to create.</returns>
-        Size GetRenderTargetSize(VisualBrush brush);
+        Size GetRenderTargetSize(IVisualBrush brush);
 
         /// <summary>
         /// Renders a visual brush to a bitmap.
@@ -25,6 +25,6 @@ namespace Avalonia.Rendering
         /// <param name="context">The drawing context to render to.</param>
         /// <param name="brush">The visual brush.</param>
         /// <returns>A bitmap containing the rendered brush.</returns>
-        void RenderVisualBrush(IDrawingContextImpl context, VisualBrush brush);
+        void RenderVisualBrush(IDrawingContextImpl context, IVisualBrush brush);
     }
 }

src/Avalonia.Visuals/Rendering/ImmediateRenderer.cs

@@ -79,13 +79,13 @@ namespace Avalonia.Rendering
         {
         }
 
-        Size IVisualBrushRenderer.GetRenderTargetSize(VisualBrush brush)
+        Size IVisualBrushRenderer.GetRenderTargetSize(IVisualBrush brush)
         {
             (brush.Visual as IVisualBrushInitialize)?.EnsureInitialized();
             return brush.Visual?.Bounds.Size ?? Size.Empty;
         }
 
-        void IVisualBrushRenderer.RenderVisualBrush(IDrawingContextImpl context, VisualBrush brush)
+        void IVisualBrushRenderer.RenderVisualBrush(IDrawingContextImpl context, IVisualBrush brush)
         {
             var visual = brush.Visual;
             Render(new DrawingContext(context), visual, visual.Bounds);

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

@@ -0,0 +1,48 @@
+using System;
+using Avalonia.Media;
+using Avalonia.Rendering.SceneGraph.Media;
+
+namespace Avalonia.Rendering.SceneGraph
+{
+    public abstract class BrushDrawOperation : IDrawOperation
+    {
+        public abstract Rect Bounds { get; }
+        public abstract bool HitTest(Point p);
+        public abstract void Render(IDrawingContextImpl context);
+
+        protected IBrush Convert(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;
+            }
+        }
+
+        protected Pen Convert(Pen pen)
+        {
+            var brush = pen?.Brush != null ? Convert(pen.Brush) : null;
+            return ReferenceEquals(pen?.Brush, brush) ?
+                pen :
+                new Pen(
+                    pen.Brush,
+                    thickness: pen.Thickness,
+                    dashStyle: pen.DashStyle,
+                    dashCap: pen.DashCap,
+                    startLineCap: pen.StartLineCap,
+                    endLineCap: pen.EndLineCap,
+                    lineJoin: pen.LineJoin,
+                    miterLimit: pen.MiterLimit);
+        }
+    }
+}

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

@@ -7,18 +7,18 @@ using Avalonia.Platform;
 
 namespace Avalonia.Rendering.SceneGraph
 {
-    public class GeometryNode : IDrawOperation
+    public class GeometryNode : BrushDrawOperation
     {
         public GeometryNode(Matrix transform, IBrush brush, Pen pen, IGeometryImpl geometry)
         {
             Bounds = geometry.GetRenderBounds(pen.Thickness).TransformToAABB(transform);
             Transform = transform;
-            Brush = brush;
-            Pen = pen;
+            Brush = Convert(brush);
+            Pen = Convert(pen);
             Geometry = geometry;
         }
 
-        public Rect Bounds { get; }
+        public override Rect Bounds { get; }
         public Matrix Transform { get; }
         public IBrush Brush { get; }
         public Pen Pen { get; }
@@ -32,13 +32,13 @@ namespace Avalonia.Rendering.SceneGraph
                 Equals(geometry, Geometry);
         }
 
-        public void Render(IDrawingContextImpl context)
+        public override void Render(IDrawingContextImpl context)
         {
             context.Transform = Transform;
             context.DrawGeometry(Brush, Pen, Geometry);
         }
 
-        public bool HitTest(Point p)
+        public override bool HitTest(Point p)
         {
             p *= Transform.Invert();
             return (Brush != null && Geometry.FillContains(p)) || 

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

@@ -6,18 +6,18 @@ using Avalonia.Media;
 
 namespace Avalonia.Rendering.SceneGraph
 {
-    public class LineNode : IDrawOperation
+    public class LineNode : BrushDrawOperation
     {
         public LineNode(Matrix transform, Pen pen, Point p1, Point p2)
         {
             Bounds = new Rect(P1, P2);
             Transform = transform;
-            Pen = pen;
+            Pen = Convert(pen);
             P1 = p1;
             P2 = p2;
         }
 
-        public Rect Bounds { get; }
+        public override Rect Bounds { get; }
         public Matrix Transform { get; }
         public Pen Pen { get; }
         public Point P1 { get; }
@@ -28,13 +28,13 @@ namespace Avalonia.Rendering.SceneGraph
             return transform == Transform && pen == Pen && p1 == P1 && p2 == P2;
         }
 
-        public void Render(IDrawingContextImpl context)
+        public override void Render(IDrawingContextImpl context)
         {
             context.Transform = Transform;
             context.DrawLine(Pen, P1, P2);
         }
 
-        public bool HitTest(Point p)
+        public override bool HitTest(Point p)
         {
             // TODO: Implement line hit testing.
             return false;

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

@@ -0,0 +1,37 @@
+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

@@ -0,0 +1,37 @@
+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

@@ -6,19 +6,19 @@ using Avalonia.Media;
 
 namespace Avalonia.Rendering.SceneGraph
 {
-    public class RectangleNode : IDrawOperation
+    public class RectangleNode : BrushDrawOperation
     {
         public RectangleNode(Matrix transform, IBrush brush, Pen pen, Rect rect, float cornerRadius)
         {
             Bounds = rect.TransformToAABB(transform).Inflate(pen?.Thickness ?? 0);
             Transform = transform;
-            Brush = brush;
-            Pen = pen;
+            Brush = Convert(brush);
+            Pen = Convert(pen);
             Rect = rect;
             CornerRadius = cornerRadius;
         }
 
-        public Rect Bounds { get; }
+        public override Rect Bounds { get; }
         public Matrix Transform { get; }
         public IBrush Brush { get; }
         public Pen Pen { get; }
@@ -34,7 +34,7 @@ namespace Avalonia.Rendering.SceneGraph
                 cornerRadius == CornerRadius;
         }
 
-        public void Render(IDrawingContextImpl context)
+        public override void Render(IDrawingContextImpl context)
         {
             context.Transform = Transform;
 
@@ -49,6 +49,6 @@ namespace Avalonia.Rendering.SceneGraph
             }
         }
 
-        public bool HitTest(Point p) => Bounds.Contains(p);
+        public override bool HitTest(Point p) => Bounds.Contains(p);
     }
 }

src/Avalonia.Visuals/Rendering/Utilities/TileBrushCalculator.cs

@@ -18,7 +18,7 @@ namespace Avalonia.Rendering.Utilities
         /// <param name="brush">The brush to be rendered.</param>
         /// <param name="contentSize">The size of the content of the tile brush.</param>
         /// <param name="targetSize">The size of the control to which the brush is being rendered.</param>
-        public TileBrushCalculator(TileBrush brush, Size contentSize, Size targetSize)
+        public TileBrushCalculator(ITileBrush brush, Size contentSize, Size targetSize)
             : this(
                   brush.TileMode,
                   brush.Stretch,

src/Windows/Avalonia.Direct2D1/Media/DrawingContextImpl.cs

@@ -321,8 +321,8 @@ namespace Avalonia.Direct2D1.Media
             var solidColorBrush = brush as Avalonia.Media.ISolidColorBrush;
             var linearGradientBrush = brush as Avalonia.Media.LinearGradientBrush;
             var radialGradientBrush = brush as Avalonia.Media.RadialGradientBrush;
-            var imageBrush = brush as Avalonia.Media.ImageBrush;
-            var visualBrush = brush as Avalonia.Media.VisualBrush;
+            var imageBrush = brush as Avalonia.Media.IImageBrush;
+            var visualBrush = brush as Avalonia.Media.IVisualBrush;
 
             if (solidColorBrush != null)
             {

src/Windows/Avalonia.Direct2D1/Media/ImageBrushImpl.cs

@@ -11,7 +11,7 @@ namespace Avalonia.Direct2D1.Media
     public sealed class ImageBrushImpl : BrushImpl
     {
         public ImageBrushImpl(
-            TileBrush brush,
+            ITileBrush brush,
             SharpDX.Direct2D1.RenderTarget target,
             BitmapImpl bitmap,
             Size targetSize)
@@ -45,7 +45,7 @@ namespace Avalonia.Direct2D1.Media
             base.Dispose();
         }
 
-        private static BitmapBrushProperties GetBitmapBrushProperties(TileBrush brush)
+        private static BitmapBrushProperties GetBitmapBrushProperties(ITileBrush brush)
         {
             var tileMode = brush.TileMode;
 
@@ -56,7 +56,7 @@ namespace Avalonia.Direct2D1.Media
             };
         }
 
-        private static BrushProperties GetBrushProperties(TileBrush brush, Rect destinationRect)
+        private static BrushProperties GetBrushProperties(ITileBrush brush, Rect destinationRect)
         {
             var tileTransform =
                 brush.TileMode != TileMode.None ?

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

@@ -2,51 +2,12 @@
   <Settings>
     <DefaultTestTimeout>1000</DefaultTestTimeout>
     <IgnoredTests>
-      <NamedTestSelector>
-        <TestName>Avalonia.Direct2D1.RenderTests.Media.ImageBrushTests.ImageBrush_NoStretch_FlipX_TopLeftDest</TestName>
-      </NamedTestSelector>
       <FixtureTestSelector>
         <FixtureName>Avalonia.Direct2D1.RenderTests.Media.LinearGradientBrushTests</FixtureName>
       </FixtureTestSelector>
-      <FixtureTestSelector>
-        <FixtureName>Avalonia.Direct2D1.RenderTests.Media.VisualBrushTests</FixtureName>
-      </FixtureTestSelector>
       <FixtureTestSelector>
         <FixtureName>Avalonia.Direct2D1.RenderTests.Controls.BorderTests</FixtureName>
       </FixtureTestSelector>
-      <NamedTestSelector>
-        <TestName>Avalonia.Direct2D1.RenderTests.Media.ImageBrushTests.ImageBrush_NoStretch_FlipXY_TopLeftDest</TestName>
-      </NamedTestSelector>
-      <NamedTestSelector>
-        <TestName>Avalonia.Direct2D1.RenderTests.Media.ImageBrushTests.ImageBrush_NoStretch_FlipY_TopLeftDest</TestName>
-      </NamedTestSelector>
-      <NamedTestSelector>
-        <TestName>Avalonia.Direct2D1.RenderTests.Media.ImageBrushTests.ImageBrush_NoStretch_NoTile_Alignment_BottomRight</TestName>
-      </NamedTestSelector>
-      <NamedTestSelector>
-        <TestName>Avalonia.Direct2D1.RenderTests.Media.ImageBrushTests.ImageBrush_NoStretch_NoTile_Alignment_Center</TestName>
-      </NamedTestSelector>
-      <NamedTestSelector>
-        <TestName>Avalonia.Direct2D1.RenderTests.Media.ImageBrushTests.ImageBrush_NoStretch_NoTile_Alignment_TopLeft</TestName>
-      </NamedTestSelector>
-      <NamedTestSelector>
-        <TestName>Avalonia.Direct2D1.RenderTests.Media.ImageBrushTests.ImageBrush_NoStretch_NoTile_BottomRightQuarterDest</TestName>
-      </NamedTestSelector>
-      <NamedTestSelector>
-        <TestName>Avalonia.Direct2D1.RenderTests.Media.ImageBrushTests.ImageBrush_NoStretch_NoTile_BottomRightQuarterSource</TestName>
-      </NamedTestSelector>
-      <NamedTestSelector>
-        <TestName>Avalonia.Direct2D1.RenderTests.Media.ImageBrushTests.ImageBrush_NoStretch_NoTile_BottomRightQuarterSource_BottomRightQuarterDest</TestName>
-      </NamedTestSelector>
-      <NamedTestSelector>
-        <TestName>Avalonia.Direct2D1.RenderTests.Media.ImageBrushTests.ImageBrush_NoStretch_Tile_BottomRightQuarterSource_CenterQuarterDest</TestName>
-      </NamedTestSelector>
-      <NamedTestSelector>
-        <TestName>Avalonia.Direct2D1.RenderTests.Media.ImageBrushTests.ImageBrush_Uniform_NoTile</TestName>
-      </NamedTestSelector>
-      <NamedTestSelector>
-        <TestName>Avalonia.Direct2D1.RenderTests.Media.ImageBrushTests.ImageBrush_UniformToFill_NoTile</TestName>
-      </NamedTestSelector>
       <FixtureTestSelector>
         <FixtureName>Avalonia.Direct2D1.RenderTests.Controls.ImageTests</FixtureName>
       </FixtureTestSelector>