Make DPI scaling work again.

src/Avalonia.Controls/TopLevel.cs

@@ -220,6 +220,9 @@ namespace Avalonia.Controls
         /// <inheritdoc/>
         double ILayoutRoot.LayoutScaling => PlatformImpl.Scaling;
 
+        /// <inheritdoc/>
+        double IRenderRoot.RenderScaling => PlatformImpl.Scaling;
+
         IStyleHost IStyleHost.StylingParent
         {
             get { return AvaloniaLocator.Current.GetService<IGlobalStyles>(); }

src/Avalonia.Visuals/Media/Imaging/RenderTargetBitmap.cs

@@ -3,7 +3,6 @@
 
 using System;
 using Avalonia.Platform;
-using Avalonia.Rendering;
 using Avalonia.VisualTree;
 
 namespace Avalonia.Media.Imaging
@@ -16,10 +15,12 @@ namespace Avalonia.Media.Imaging
         /// <summary>
         /// Initializes a new instance of the <see cref="RenderTargetBitmap"/> class.
         /// </summary>
-        /// <param name="width">The width of the bitmap.</param>
-        /// <param name="height">The height of the bitmap.</param>
-        public RenderTargetBitmap(int width, int height)
-            : base(CreateImpl(width, height))
+        /// <param name="pixelWidth">The width of the bitmap in pixels.</param>
+        /// <param name="pixelHeight">The height of the bitmap in pixels.</param>
+        /// <param name="dpiX">The horizontal DPI of the bitmap.</param>
+        /// <param name="dpiY">The vertical DPI of the bitmap.</param>
+        public RenderTargetBitmap(int pixelWidth, int pixelHeight, double dpiX = 96, double dpiY = 96)
+            : base(CreateImpl(pixelWidth, pixelHeight, dpiX, dpiY))
         {
         }
 
@@ -41,11 +42,13 @@ namespace Avalonia.Media.Imaging
         /// </summary>
         /// <param name="width">The width of the bitmap.</param>
         /// <param name="height">The height of the bitmap.</param>
+        /// <param name="dpiX">The horizontal DPI of the bitmap.</param>
+        /// <param name="dpiY">The vertical DPI of the bitmap.</param>
         /// <returns>The platform-specific implementation.</returns>
-        private static IBitmapImpl CreateImpl(int width, int height)
+        private static IBitmapImpl CreateImpl(int width, int height, double dpiX, double dpiY)
         {
             IPlatformRenderInterface factory = AvaloniaLocator.Current.GetService<IPlatformRenderInterface>();
-            return factory.CreateRenderTargetBitmap(width, height);
+            return factory.CreateRenderTargetBitmap(width, height, dpiX, dpiY);
         }
 
         public IDrawingContextImpl CreateDrawingContext() => PlatformImpl.CreateDrawingContext();

src/Avalonia.Visuals/Platform/IPlatformRenderInterface.cs

@@ -51,8 +51,14 @@ namespace Avalonia.Platform
         /// </summary>
         /// <param name="width">The width of the bitmap.</param>
         /// <param name="height">The height of the bitmap.</param>
+        /// <param name="dpiX">The horizontal DPI of the bitmap.</param>
+        /// <param name="dpiY">The vertical DPI of the bitmap.</param>
         /// <returns>An <see cref="IRenderTargetBitmapImpl"/>.</returns>
-        IRenderTargetBitmapImpl CreateRenderTargetBitmap(int width, int height);
+        IRenderTargetBitmapImpl CreateRenderTargetBitmap(
+            int width,
+            int height,
+            double dpiX,
+            double dpiY);
 
         /// <summary>
         /// Loads a bitmap implementation from a file..

src/Avalonia.Visuals/Rendering/DefaultRenderLayerFactory.cs

@@ -18,11 +18,17 @@ namespace Avalonia.Rendering
             _renderInterface = renderInterface;
         }
 
-        public IRenderTargetBitmapImpl CreateLayer(IVisual layerRoot, Size size)
+        public IRenderTargetBitmapImpl CreateLayer(
+            IVisual layerRoot,
+            Size size,
+            double dpiX,
+            double dpiY)
         {
             return _renderInterface.CreateRenderTargetBitmap(
                 (int)Math.Ceiling(size.Width),
-                (int)Math.Ceiling(size.Height));
+                (int)Math.Ceiling(size.Height),
+                dpiX,
+                dpiY);
         }
     }
 }

src/Avalonia.Visuals/Rendering/DeferredRenderer.cs

@@ -166,7 +166,7 @@ namespace Avalonia.Rendering
         {
             if (DrawFps || DrawDirtyRects)
             {
-                var overlay = GetOverlay(scene.Size);
+                var overlay = GetOverlay(scene.Size, scene.Scaling);
 
                 using (var context = overlay.CreateDrawingContext())
                 {
@@ -240,13 +240,15 @@ namespace Avalonia.Rendering
 
                     foreach (var layer in scene.Layers)
                     {
-                        var renderLayer = _layers[layer.LayerRoot];
-                        context.DrawImage(renderLayer.Bitmap, layer.Opacity, clientRect, clientRect);
+                        var bitmap = _layers[layer.LayerRoot].Bitmap;
+                        var sourceRect = new Rect(0, 0, bitmap.PixelWidth, bitmap.PixelHeight);
+                        context.DrawImage(bitmap, layer.Opacity, sourceRect, clientRect);
                     }
 
                     if (_overlay != null)
                     {
-                        context.DrawImage(_overlay, 0.5, clientRect, clientRect);
+                        var sourceRect = new Rect(0, 0, _overlay.PixelWidth, _overlay.PixelHeight);
+                        context.DrawImage(_overlay, 0.5, sourceRect, clientRect);
                     }
                 }
             }
@@ -316,15 +318,16 @@ namespace Avalonia.Rendering
             Render(scene);
         }
 
-        private IRenderTargetBitmapImpl GetOverlay(Size size)
+        private IRenderTargetBitmapImpl GetOverlay(Size size, double scaling)
         {
-            int width = (int)Math.Ceiling(size.Width);
-            int height = (int)Math.Ceiling(size.Height);
+            size = new Size(size.Width * scaling, size.Height * scaling);
 
-            if (_overlay == null || _overlay.PixelWidth != width || _overlay.PixelHeight != height)
+            if (_overlay == null ||
+                _overlay.PixelWidth != size.Width ||
+                _overlay.PixelHeight != size.Height)
             {
                 _overlay?.Dispose();
-                _overlay = _layerFactory.CreateLayer(null, size);
+                _overlay = _layerFactory.CreateLayer(null, size, 96 * scaling, 96 * scaling);
             }
 
             return _overlay;
@@ -332,18 +335,19 @@ namespace Avalonia.Rendering
 
         private IRenderTargetBitmapImpl GetRenderTargetForLayer(Scene scene, IVisual layerRoot)
         {
+            var size = new Size(scene.Size.Width * scene.Scaling, scene.Size.Height * scene.Scaling);
             RenderLayer result;
 
             if (_layers.TryGetValue(layerRoot, out result))
             {
                 if (result.Size != scene.Size)
                 {
-                    result.ResizeBitmap(scene.Size);
+                    result.ResizeBitmap(size, scene.Scaling);
                 }
             }
             else
             {
-                _layers.Add(layerRoot, scene.Size);
+                _layers.Add(layerRoot, size, scene.Scaling);
             }
 
             return _layers[layerRoot].Bitmap;

src/Avalonia.Visuals/Rendering/IRenderLayerFactory.cs

@@ -6,6 +6,6 @@ namespace Avalonia.Rendering
 {
     public interface IRenderLayerFactory
     {
-        IRenderTargetBitmapImpl CreateLayer(IVisual layerRoot, Size size);
+        IRenderTargetBitmapImpl CreateLayer(IVisual layerRoot, Size size, double dpiX, double dpiY);
     }
 }

src/Avalonia.Visuals/Rendering/IRenderRoot.cs

@@ -22,6 +22,8 @@ namespace Avalonia.Rendering
         /// </summary>
         IRenderer Renderer { get; }
 
+        double RenderScaling { get; }
+
         /// <summary>
         /// Creates a render target for the window.
         /// </summary>

src/Avalonia.Visuals/Rendering/RenderLayer.cs

@@ -12,23 +12,26 @@ namespace Avalonia.Rendering
         public RenderLayer(
             IRenderLayerFactory factory,
             Size size,
+            double scaling,
             IVisual layerRoot)
         {
             _factory = factory;
-            Bitmap = factory.CreateLayer(layerRoot, size);
+            Bitmap = factory.CreateLayer(layerRoot, size, 96 * scaling, 96 * scaling);
             Size = size;
+            Scaling = scaling;
             LayerRoot = layerRoot;
         }
 
         public IRenderTargetBitmapImpl Bitmap { get; private set; }
+        public double Scaling { get; private set; }
         public Size Size { get; private set; }
         public IVisual LayerRoot { get; }
 
-        public void ResizeBitmap(Size size)
+        public void ResizeBitmap(Size size, double scaling)
         {
-            if (Size != size)
+            if (Size != size || Scaling != scaling)
             {
-                var resized = _factory.CreateLayer(LayerRoot, size);
+                var resized = _factory.CreateLayer(LayerRoot, size, 96 * scaling, 96 * scaling);
 
                 using (var context = resized.CreateDrawingContext())
                 {

src/Avalonia.Visuals/Rendering/RenderLayers.cs

@@ -20,13 +20,13 @@ namespace Avalonia.Rendering
         public int Count => _inner.Count;
         public RenderLayer this[IVisual layerRoot] => _index[layerRoot];
 
-        public RenderLayer Add(IVisual layerRoot, Size size)
+        public RenderLayer Add(IVisual layerRoot, Size size, double scaling)
         {
             RenderLayer result;
 
             if (!_index.TryGetValue(layerRoot, out result))
             {
-                result = new RenderLayer(_factory, size, layerRoot);
+                result = new RenderLayer(_factory, size, scaling, layerRoot);
                 _inner.Add(result);
                 _index.Add(layerRoot, result);
             }

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

@@ -34,6 +34,7 @@ namespace Avalonia.Rendering.SceneGraph
         public SceneLayers Layers { get; }
         public IVisualNode Root { get; }
         public Size Size { get; set; }
+        public double Scaling { get; set; } = 1;
 
         public void Add(IVisualNode node)
         {
@@ -50,6 +51,7 @@ namespace Avalonia.Rendering.SceneGraph
             var result = new Scene(root, index, Layers.Clone(), Id + 1)
             {
                 Size = Size,
+                Scaling = Scaling,
             };
 
             return result;

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

@@ -16,7 +16,7 @@ namespace Avalonia.Rendering.SceneGraph
             Contract.Requires<ArgumentNullException>(scene != null);
             Dispatcher.UIThread.VerifyAccess();
 
-            scene.Size = (scene.Root.Visual as IRenderRoot)?.ClientSize ?? scene.Root.Visual.Bounds.Size;
+            UpdateSize(scene);
             scene.Layers.GetOrAdd(scene.Root.Visual);
 
             using (var impl = new DeferredDrawingContextImpl(scene.Layers))
@@ -203,7 +203,10 @@ namespace Avalonia.Rendering.SceneGraph
 
         private void UpdateSize(Scene scene)
         {
-            var newSize = (scene.Root.Visual as IRenderRoot)?.ClientSize ?? scene.Root.Visual.Bounds.Size;
+            var renderRoot = scene.Root.Visual as IRenderRoot;
+            var newSize = renderRoot?.ClientSize ?? scene.Root.Visual.Bounds.Size;
+
+            scene.Scaling = renderRoot?.RenderScaling ?? 1;
 
             if (scene.Size != newSize)
             {

src/Gtk/Avalonia.Cairo/CairoPlatform.cs

@@ -71,7 +71,7 @@ namespace Avalonia.Cairo
                 handle.HandleDescriptor));
         }
 
-        public IRenderTargetBitmapImpl CreateRenderTargetBitmap(int width, int height)
+        public IRenderTargetBitmapImpl CreateRenderTargetBitmap(int width, int height, double dpiX, double dpiY)
         {
             return new RenderTargetBitmapImpl(new ImageSurface(Format.Argb32, width, height));
         }

src/Skia/Avalonia.Skia/PlatformRenderInterface.cs

@@ -11,7 +11,7 @@ namespace Avalonia.Skia
     {
         public IBitmapImpl CreateBitmap(int width, int height)
         {
-            return CreateRenderTargetBitmap(width, height);
+            return CreateRenderTargetBitmap(width, height, 96, 96);
         }
 
         public IFormattedTextImpl CreateFormattedText(string text, string fontFamilyName, double fontSize, FontStyle fontStyle,
@@ -54,7 +54,11 @@ namespace Avalonia.Skia
             return new Renderer(root, renderLoop);
         }
 
-        public IRenderTargetBitmapImpl CreateRenderTargetBitmap(int width, int height)
+        public IRenderTargetBitmapImpl CreateRenderTargetBitmap(
+            int width,
+            int height,
+            double dpiX,
+            double dpiY)
         {
             if (width < 1)
                 throw new ArgumentException("Width can't be less than 1", nameof(width));

src/Windows/Avalonia.Direct2D1/Avalonia.Direct2D1.csproj

@@ -41,8 +41,8 @@
       <HintPath>..\..\..\packages\SharpDX.3.1.1\lib\net45\SharpDX.dll</HintPath>
       <Private>True</Private>
     </Reference>
-    <Reference Include="SharpDX.Direct2D1, Version=3.1.0.0, Culture=neutral, PublicKeyToken=b4dcf0f35e5521f1, processorArchitecture=MSIL">
-      <HintPath>..\..\..\packages\SharpDX.Direct2D1.3.1.0\lib\net45\SharpDX.Direct2D1.dll</HintPath>
+    <Reference Include="SharpDX.Direct2D1, Version=3.1.1.0, Culture=neutral, PublicKeyToken=b4dcf0f35e5521f1, processorArchitecture=MSIL">
+      <HintPath>..\..\..\packages\SharpDX.Direct2D1.3.1.1\lib\net45\SharpDX.Direct2D1.dll</HintPath>
       <Private>True</Private>
     </Reference>
     <Reference Include="SharpDX.Direct3D11, Version=3.1.1.0, Culture=neutral, PublicKeyToken=b4dcf0f35e5521f1, processorArchitecture=MSIL">

src/Windows/Avalonia.Direct2D1/Direct2D1Platform.cs

@@ -93,9 +93,20 @@ namespace Avalonia.Direct2D1
             }
         }
 
-        public IRenderTargetBitmapImpl CreateRenderTargetBitmap(int width, int height)
+        public IRenderTargetBitmapImpl CreateRenderTargetBitmap(
+            int width,
+            int height,
+            double dpiX,
+            double dpiY)
         {
-            return new RenderTargetBitmapImpl(s_imagingFactory, s_d2D1Factory, s_dwfactory, width, height);
+            return new RenderTargetBitmapImpl(
+                s_imagingFactory,
+                s_d2D1Factory,
+                s_dwfactory,
+                width,
+                height,
+                dpiX,
+                dpiY);
         }
 
         public IStreamGeometryImpl CreateStreamGeometry()

src/Windows/Avalonia.Direct2D1/HwndRenderTarget.cs

@@ -17,8 +17,8 @@ namespace Avalonia.Direct2D1
         private readonly SharpDX.Direct3D11.Device _d3dDevice;
         private DeviceContext _deviceContext;
         private SharpDX.DXGI.SwapChain1 _swapChain;
-        private Size2 _savedSize;
-        private Size2F _savedDpi;
+        private Size2 _size;
+        private Size2F _dpi;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="HwndRenderTarget"/> class.
@@ -48,7 +48,9 @@ namespace Avalonia.Direct2D1
                 SharpDX.Direct3D11.DeviceCreationFlags.BgraSupport,
                 featureLevels);
 
-            CreateSwapChain();
+            var size = GetWindowSize();
+            var dpi = GetWindowDpi();
+            CreateSwapChain(size, dpi);
         }
 
         /// <summary>
@@ -76,11 +78,9 @@ namespace Avalonia.Direct2D1
             var size = GetWindowSize();
             var dpi = GetWindowDpi();
 
-            if (size != _savedSize || dpi != _savedDpi)
+            if (size != _size || _dpi != dpi)
             {
-                _savedSize = size;
-                _savedDpi = dpi;
-                CreateSwapChain();
+                CreateSwapChain(size, dpi);
             }
 
             return new DrawingContextImpl(_deviceContext, DirectWriteFactory, _swapChain);
@@ -93,8 +93,11 @@ namespace Avalonia.Direct2D1
             _d3dDevice.Dispose();
         }
 
-        private void CreateSwapChain()
+        private void CreateSwapChain(Size2 size, Size2F dpi)
         {
+            _size = size;
+            _dpi = dpi;
+
             using (var dxgiDevice = _d3dDevice.QueryInterface<SharpDX.DXGI.Device>())
             using (var d2dDevice = new Device(dxgiDevice))
             using (var dxgiAdaptor = dxgiDevice.Adapter)
@@ -102,6 +105,7 @@ namespace Avalonia.Direct2D1
             {
                 _deviceContext?.Dispose();
                 _deviceContext = new DeviceContext(d2dDevice, DeviceContextOptions.None);
+                _deviceContext.DotsPerInch = dpi;
 
                 var swapChainDesc = new SharpDX.DXGI.SwapChainDescription1
                 {
@@ -121,8 +125,6 @@ namespace Avalonia.Direct2D1
                     Flags = 0,
                 };
 
-                var dpi = Direct2DFactory.DesktopDpi;
-
                 _swapChain?.Dispose();
                 _swapChain = new SharpDX.DXGI.SwapChain1(dxgiFactory, _d3dDevice, _hwnd, ref swapChainDesc);
 
@@ -144,7 +146,6 @@ namespace Avalonia.Direct2D1
                 }
             }
         }
-
         private Size2F GetWindowDpi()
         {
             if (UnmanagedMethods.ShCoreAvailable)

src/Windows/Avalonia.Direct2D1/Media/Imaging/RenderTargetBitmapImpl.cs

@@ -20,13 +20,15 @@ namespace Avalonia.Direct2D1.Media
             Factory d2dFactory,
             DirectWriteFactory dwriteFactory,
             int width,
-            int height)
+            int height,
+            double dpiX,
+            double dpiY)
             : base(imagingFactory, width, height)
         {
             var props = new RenderTargetProperties
             {
-                DpiX = 96,
-                DpiY = 96,
+                DpiX = (float)dpiX,
+                DpiY = (float)dpiY,
             };
 
             _target = new WicRenderTarget(

src/Windows/Avalonia.Direct2D1/packages.config

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="SharpDX" version="3.1.1" targetFramework="net45" />
-  <package id="SharpDX.Direct2D1" version="3.1.0" targetFramework="net45" />
+  <package id="SharpDX.Direct2D1" version="3.1.1" targetFramework="net45" />
   <package id="SharpDX.Direct3D11" version="3.1.1" targetFramework="net45" />
   <package id="SharpDX.DXGI" version="3.1.1" targetFramework="net45" />
 </packages>

tests/Avalonia.Controls.UnitTests/Presenters/ItemsPresenterTests_Virtualization.cs

@@ -318,6 +318,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
         {
             public IRenderer Renderer { get; }
             public Size ClientSize { get; }
+            public double RenderScaling => 1;
 
             public IRenderTarget CreateRenderTarget()
             {

tests/Avalonia.Controls.UnitTests/Presenters/ItemsPresenterTests_Virtualization_Simple.cs

@@ -993,6 +993,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
         {
             public IRenderer Renderer { get; }
             public Size ClientSize { get; }
+            public double RenderScaling => 1;
 
             public IRenderTarget CreateRenderTarget()
             {

tests/Avalonia.UnitTests/TestRoot.cs

@@ -48,6 +48,8 @@ namespace Avalonia.UnitTests
 
         public double LayoutScaling => 1;
 
+        public double RenderScaling => 1;
+
         public ILayoutManager LayoutManager => AvaloniaLocator.Current.GetService<ILayoutManager>();
 
         public IRenderTarget RenderTarget => null;

tests/Avalonia.UnitTests/TestTemplatedRoot.cs

@@ -39,6 +39,8 @@ namespace Avalonia.UnitTests
 
         public double LayoutScaling => 1;
 
+        public double RenderScaling => 1;
+
         public ILayoutManager LayoutManager => AvaloniaLocator.Current.GetService<ILayoutManager>();
 
         public IRenderTarget RenderTarget => null;

tests/Avalonia.Visuals.UnitTests/Rendering/DeferredRendererTests.cs

@@ -141,7 +141,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering
                 });
 
             var layers = new Mock<IRenderLayerFactory>();
-            layers.Setup(x => x.CreateLayer(root, root.ClientSize)).Returns(CreateLayer());
+            layers.Setup(x => x.CreateLayer(root, root.ClientSize, 96, 96)).Returns(CreateLayer());
 
             var renderInterface = new Mock<IPlatformRenderInterface>();
 
@@ -154,7 +154,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering
 
             RunFrame(loop);
 
-            layers.Verify(x => x.CreateLayer(root, root.ClientSize));
+            layers.Verify(x => x.CreateLayer(root, root.ClientSize, 96, 96));
         }
 
         [Fact]
@@ -241,7 +241,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering
         private Mock<IRenderLayerFactory> MockLayerFactory(IRenderRoot root)
         {
             var result = new Mock<IRenderLayerFactory>();
-            result.Setup(x => x.CreateLayer(root, root.ClientSize)).Returns(CreateLayer());
+            result.Setup(x => x.CreateLayer(root, root.ClientSize, 96, 96)).Returns(CreateLayer());
             return result;
         }
 
@@ -262,7 +262,11 @@ namespace Avalonia.Visuals.UnitTests.Rendering
                 _layers = layers;
             }
 
-            public IRenderTargetBitmapImpl CreateLayer(IVisual layerRoot, Size size)
+            public IRenderTargetBitmapImpl CreateLayer(
+                IVisual layerRoot,
+                Size size,
+                double dpiX,
+                double dpiY)
             {
                 return _layers[layerRoot];
             }

tests/Avalonia.Visuals.UnitTests/VisualTree/MockRenderInterface.cs

@@ -26,7 +26,11 @@ namespace Avalonia.Visuals.UnitTests.VisualTree
             throw new NotImplementedException();
         }
 
-        public IRenderTargetBitmapImpl CreateRenderTargetBitmap(int width, int height)
+        public IRenderTargetBitmapImpl CreateRenderTargetBitmap(
+            int width,
+            int height,
+            double dpiX,
+            double dpiY)
         {
             throw new NotImplementedException();
         }