Disable render layers.

We need a new renderer :/

Fixes #2244

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

@@ -394,13 +394,8 @@ namespace Avalonia.Rendering.SceneGraph
             }
         }
 
-        private static bool ShouldStartLayer(IVisual visual)
-        {
-            var o = visual as IAvaloniaObject;
-            return visual.VisualChildren.Count > 0 &&
-                o != null &&
-                o.IsAnimating(Visual.OpacityProperty);
-        }
+        // HACK: Disabled layers because they're broken in current renderer. See #2244.
+        private static bool ShouldStartLayer(IVisual visual) => false;
 
         private static IGeometryImpl CreateLayerGeometryClip(VisualNode node)
         {

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

@@ -557,7 +557,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering
             }
         }
 
-        [Fact]
+        [Fact(Skip = "Layers are disabled. See #2244")]
         public void Should_Create_And_Delete_Layers_For_Controls_With_Animated_Opacity()
         {
             using (UnitTestApplication.Start(TestServices.MockPlatformRenderInterface))
@@ -599,7 +599,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering
             }
         }
 
-        [Fact]
+        [Fact(Skip = "Layers are disabled. See #2244")]
         public void Should_Not_Create_Layer_For_Childless_Control_With_Animated_Opacity()
         {
             using (UnitTestApplication.Start(TestServices.MockPlatformRenderInterface))
@@ -629,7 +629,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering
             }
         }
 
-        [Fact]
+        [Fact(Skip = "Layers are disabled. See #2244")]
         public void Should_Not_Push_Opacity_For_Transparent_Layer_Root_Control()
         {
             using (UnitTestApplication.Start(TestServices.MockPlatformRenderInterface))
@@ -658,7 +658,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering
             }
         }
 
-        [Fact]
+        [Fact(Skip = "Layers are disabled. See #2244")]
         public void Should_Draw_Transparent_Layer_With_Correct_Opacity()
         {
             using (UnitTestApplication.Start(TestServices.MockPlatformRenderInterface))

tests/Avalonia.Visuals.UnitTests/Rendering/SceneGraph/SceneBuilderTests.cs

@@ -810,7 +810,9 @@ namespace Avalonia.Visuals.UnitTests.Rendering.SceneGraph
                 };
 
                 Assert.Equal(expected, scene.Layers[tree].Dirty.ToArray());
-                Assert.Equal(expected, scene.Layers[border].Dirty.ToArray());
+                
+                // Layers are disabled. See #2244
+                // Assert.Equal(expected, scene.Layers[border].Dirty.ToArray());
             }
         }
 

tests/Avalonia.Visuals.UnitTests/Rendering/SceneGraph/SceneBuilderTests_Layers.cs

@@ -14,7 +14,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering.SceneGraph
 {
     public partial class SceneBuilderTests
     {
-        [Fact]
+        [Fact(Skip = "Layers are disabled. See #2244")]
         public void Control_With_Animated_Opacity_And_Children_Should_Start_New_Layer()
         {
             using (UnitTestApplication.Start(TestServices.MockPlatformRenderInterface))
@@ -118,7 +118,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering.SceneGraph
             }
         }
 
-        [Fact]
+        [Fact(Skip = "Layers are disabled. See #2244")]
         public void Removing_Control_With_Animated_Opacity_Should_Remove_Layers()
         {
             using (UnitTestApplication.Start(TestServices.MockPlatformRenderInterface))
@@ -168,7 +168,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering.SceneGraph
             }
         }
 
-        [Fact]
+        [Fact(Skip = "Layers are disabled. See #2244")]
         public void Hiding_Transparent_Control_Should_Remove_Layers()
         {
             using (UnitTestApplication.Start(TestServices.MockPlatformRenderInterface))
@@ -218,7 +218,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering.SceneGraph
             }
         }
 
-        [Fact]
+        [Fact(Skip = "Layers are disabled. See #2244")]
         public void GeometryClip_Should_Affect_Child_Layers()
         {
             using (UnitTestApplication.Start(TestServices.MockPlatformRenderInterface))