From 553fbb95fc2cc4482642140d2568cb2fcfef1887 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Sat, 26 Mar 2016 15:01:53 +0100
Subject: [PATCH] Removed RenderTargetDecorator.

Handle scaling in D2D's RenderTarget itself.
---
 .../Platform/PlatformManager.cs               | 36 +-----------
 src/Windows/Perspex.Direct2D1/RenderTarget.cs | 58 ++++++++++++++-----
 src/Windows/Perspex.Win32/WindowImpl.cs       |  9 +--
 3 files changed, 53 insertions(+), 50 deletions(-)

diff --git a/src/Perspex.Controls/Platform/PlatformManager.cs b/src/Perspex.Controls/Platform/PlatformManager.cs
index b9e7aef72c..2f0695aaa5 100644
--- a/src/Perspex.Controls/Platform/PlatformManager.cs
+++ b/src/Perspex.Controls/Platform/PlatformManager.cs
@@ -1,7 +1,5 @@
 using System;
 using System.Reactive.Disposables;
-using Perspex.Input;
-using Perspex.Input.Raw;
 using Perspex.Media;
 using Perspex.Platform;
 
@@ -9,7 +7,6 @@ namespace Perspex.Controls.Platform
 {
     public static partial class PlatformManager
     {
-
         static IPlatformSettings GetSettings()
             => PerspexLocator.Current.GetService<IPlatformSettings>();
 
@@ -18,9 +15,9 @@ namespace Perspex.Controls.Platform
 
         public static IRenderTarget CreateRenderTarget(ITopLevelImpl window)
         {
-            return
-                new RenderTargetDecorator(
-                    PerspexLocator.Current.GetService<IPlatformRenderInterface>().CreateRenderer(window.Handle), window);
+            return PerspexLocator.Current
+                .GetService<IPlatformRenderInterface>()
+                .CreateRenderer(window.Handle);
         }
 
         public static IDisposable DesignerMode()
@@ -34,33 +31,6 @@ namespace Perspex.Controls.Platform
             _designerScalingFactor = factor;
         }
 
-        class RenderTargetDecorator : IRenderTarget
-        {
-            private readonly IRenderTarget _target;
-            private readonly ITopLevelImpl _window;
-
-            public RenderTargetDecorator(IRenderTarget target, ITopLevelImpl window)
-            {
-                _target = target;
-                _window = window;
-            }
-
-            public void Dispose() => _target.Dispose();
-
-            public DrawingContext CreateDrawingContext()
-            {
-                var cs = _window.ClientSize;
-                var ctx = _target.CreateDrawingContext();
-                var factor = _window.Scaling;
-                if (factor != 1)
-                {
-                    ctx.PushPostTransform(Matrix.CreateScale(factor, factor));
-                    ctx.PushTransformContainer();
-                }
-                return ctx;
-            }
-        }
-
         public static IWindowImpl CreateWindow()
         {
             var platform = PerspexLocator.Current.GetService<IWindowingPlatform>();
diff --git a/src/Windows/Perspex.Direct2D1/RenderTarget.cs b/src/Windows/Perspex.Direct2D1/RenderTarget.cs
index c835fc03e6..0d66ba99bd 100644
--- a/src/Windows/Perspex.Direct2D1/RenderTarget.cs
+++ b/src/Windows/Perspex.Direct2D1/RenderTarget.cs
@@ -2,10 +2,7 @@
 // Licensed under the MIT license. See licence.md file in the project root for full license information.
 
 using System;
-using Perspex.Direct2D1.Media;
-using Perspex.Media;
 using Perspex.Platform;
-using Perspex.Rendering;
 using Perspex.Win32.Interop;
 using SharpDX;
 using SharpDX.Direct2D1;
@@ -24,8 +21,6 @@ namespace Perspex.Direct2D1
         /// </summary>
         private readonly SharpDX.Direct2D1.RenderTarget _renderTarget;
 
-
-
         /// <summary>
         /// Initializes a new instance of the <see cref="RenderTarget"/> class.
         /// </summary>
@@ -53,13 +48,6 @@ namespace Perspex.Direct2D1
                 hwndProperties);
         }
 
-        Size2 GetWindowSize()
-        {
-            UnmanagedMethods.RECT rc;
-            UnmanagedMethods.GetClientRect(_hwnd, out rc);
-            return new Size2(rc.right - rc.left, rc.bottom - rc.top);
-        }
-
         /// <summary>
         /// Initializes a new instance of the <see cref="RenderTarget"/> class.
         /// </summary>
@@ -94,19 +82,63 @@ namespace Perspex.Direct2D1
         public DrawingContext CreateDrawingContext()
         {
             var window = _renderTarget as WindowRenderTarget;
+            var factor = 1.0;
+
             if (window != null)
             {
                 var size = GetWindowSize();
+                factor = GetWindowScaling();
+
                 if (size != _savedSize)
+                {
                     window.Resize(_savedSize = size);
+                }
+            }
+
+            var ctx = new DrawingContext(new Media.DrawingContext(_renderTarget, DirectWriteFactory));
+
+            if (factor != 1)
+            {
+                ctx.PushPostTransform(Matrix.CreateScale(factor, factor));
+                ctx.PushTransformContainer();
             }
 
-            return new DrawingContext(new Media.DrawingContext(_renderTarget, DirectWriteFactory));
+            return ctx;
         }
 
         public void Dispose()
         {
             _renderTarget.Dispose();
         }
+
+        private double GetWindowScaling()
+        {
+            if (UnmanagedMethods.ShCoreAvailable)
+            {
+                uint dpix, dpiy;
+
+                var monitor = UnmanagedMethods.MonitorFromWindow(
+                    _hwnd,
+                    UnmanagedMethods.MONITOR.MONITOR_DEFAULTTONEAREST);
+
+                if (UnmanagedMethods.GetDpiForMonitor(
+                        monitor,
+                        UnmanagedMethods.MONITOR_DPI_TYPE.MDT_EFFECTIVE_DPI,
+                        out dpix,
+                        out dpiy) == 0)
+                {
+                    return dpix / 96.0;
+                }
+            }
+
+            return 1;
+        }
+
+        private Size2 GetWindowSize()
+        {
+            UnmanagedMethods.RECT rc;
+            UnmanagedMethods.GetClientRect(_hwnd, out rc);
+            return new Size2(rc.right - rc.left, rc.bottom - rc.top);
+        }
     }
 }
diff --git a/src/Windows/Perspex.Win32/WindowImpl.cs b/src/Windows/Perspex.Win32/WindowImpl.cs
index c3e694e23c..c30aed9aa5 100644
--- a/src/Windows/Perspex.Win32/WindowImpl.cs
+++ b/src/Windows/Perspex.Win32/WindowImpl.cs
@@ -608,13 +608,14 @@ namespace Perspex.Win32
 
             Handle = new PlatformHandle(_hwnd, PlatformConstants.WindowHandleType);
 
-            var monitor = UnmanagedMethods.MonitorFromWindow(
-                _hwnd, 
-                UnmanagedMethods.MONITOR.MONITOR_DEFAULTTONEAREST);
-
             if (UnmanagedMethods.ShCoreAvailable)
             {
                 uint dpix, dpiy;
+
+                var monitor = UnmanagedMethods.MonitorFromWindow(
+                    _hwnd,
+                    UnmanagedMethods.MONITOR.MONITOR_DEFAULTTONEAREST);
+
                 if (UnmanagedMethods.GetDpiForMonitor(
                         monitor,
                         UnmanagedMethods.MONITOR_DPI_TYPE.MDT_EFFECTIVE_DPI,