From 1d1275059883ba603db9727422b5c10471776d8b Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Wed, 16 Sep 2020 03:25:47 -0700
Subject: [PATCH] allow enabling of windows.ui.composition with win32 options.

---
 src/Windows/Avalonia.Win32/Win32Platform.cs | 9 +++++++++
 src/Windows/Avalonia.Win32/WindowImpl.cs    | 3 ++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/Windows/Avalonia.Win32/Win32Platform.cs b/src/Windows/Avalonia.Win32/Win32Platform.cs
index af6058d197..7f1ac443ad 100644
--- a/src/Windows/Avalonia.Win32/Win32Platform.cs
+++ b/src/Windows/Avalonia.Win32/Win32Platform.cs
@@ -39,6 +39,15 @@ namespace Avalonia
         public bool AllowEglInitialization { get; set; } = true;
         public bool? EnableMultitouch { get; set; }
         public bool OverlayPopups { get; set; }
+
+        /// <summary>
+        /// Render Avalonia to a Texture inside the Windows.UI.Composition tree.
+        /// </summary>
+        /// <remarks>
+        /// Supported on Windows 10 build 16299 and above. Ignored on other versions.
+        /// This is recommended if you need to use AcrylicBlur or acrylic in your applications.
+        /// </remarks>
+        public bool UseWindowsUIComposition { get; set; }
     }
 }
 
diff --git a/src/Windows/Avalonia.Win32/WindowImpl.cs b/src/Windows/Avalonia.Win32/WindowImpl.cs
index 7222b66beb..a2bd7f57b9 100644
--- a/src/Windows/Avalonia.Win32/WindowImpl.cs
+++ b/src/Windows/Avalonia.Win32/WindowImpl.cs
@@ -101,7 +101,8 @@ namespace Avalonia.Win32
             };
             _rendererLock = new ManagedDeferredRendererLock();
 
-            _isUsingComposition = Win32Platform.WindowsVersion.Major >= 10 && Win32Platform.WindowsVersion.Build >= 16299 &&
+            _isUsingComposition = Win32Platform.Options.UseWindowsUIComposition &&
+                Win32Platform.WindowsVersion.Major >= 10 && Win32Platform.WindowsVersion.Build >= 16299 &&
                     Win32GlManager.EglFeature.Display is AngleWin32EglDisplay angleDisplay &&
                     angleDisplay.PlatformApi == AngleOptions.PlatformApi.DirectX11;