Added function to get viewport size of the game window when in editor. This allows for certain functions to behave correctly.

Source/Editor/Editor.cs

@@ -1408,6 +1408,23 @@ namespace FlaxEditor
             }
         }
 
+        internal void Internal_GetGameWindowViewportSize(out Float2 result)
+        {
+            result = new Float2(1280, 720);
+            var gameWin = Windows.GameWin;
+            if (gameWin?.Root?.RootWindow is WindowRootControl root)
+            {
+                // Handle case when Game window is not selected in tab view
+                var dockedTo = gameWin.ParentDockPanel;
+                if (dockedTo != null && dockedTo.SelectedTab != gameWin && dockedTo.SelectedTab != null)
+                    result = dockedTo.SelectedTab.Size * root.DpiScale;
+                else
+                    result = gameWin.Viewport.Size * root.DpiScale;
+
+                result = Float2.Round(result);
+            }
+        }
+
         internal bool Internal_OnAppExit()
         {
             // In editor play mode (when main window is not closed) just skip engine exit and leave the play mode

Source/Editor/Managed/ManagedEditor.cpp

@@ -457,6 +457,24 @@ Float2 ManagedEditor::GetGameWindowSize()
     return Float2::Zero;
 }
 
+Float2 ManagedEditor::GetGameWindowViewportSize()
+{
+    if (HasManagedInstance())
+    {
+        if (Internal_GetGameWindowSize == nullptr)
+        {
+            Internal_GetGameWindowSize = GetClass()->GetMethod("Internal_GetGameWindowViewportSize", 1);
+            ASSERT(Internal_GetGameWindowSize);
+        }
+        Float2 size;
+        void* params[1];
+        params[0] = &size;
+        Internal_GetGameWindowSize->Invoke(GetManagedInstance(), params, nullptr);
+        return size;
+    }
+    return Float2::Zero;
+}
+
 bool ManagedEditor::OnAppExit()
 {
     if (!HasManagedInstance())

Source/Editor/Managed/ManagedEditor.h

@@ -133,6 +133,12 @@ public:
     /// <returns>The size.</returns>
     Float2 GetGameWindowSize();
 
+    /// <summary>
+    /// Gets the size of the game window viewport output.
+    /// </summary>
+    /// <returns>The size.</returns>
+    Float2 GetGameWindowViewportSize();
+
     /// <summary>
     /// Called when application code calls exit. Editor may end play mode or exit normally.
     /// </summary>

Source/Engine/Level/Actors/Camera.cpp

@@ -189,7 +189,7 @@ Viewport Camera::GetViewport() const
 #if USE_EDITOR
     // Editor
     if (Editor::Managed)
-        result.Size = Editor::Managed->GetGameWindowSize();
+        result.Size = Editor::Managed->GetGameWindowViewportSize();
 #else
 	// game
 	auto mainWin = Engine::MainWindow;