Add DpiScale to RootWindow

Source/Engine/UI/GUI/Tooltip.cs

@@ -68,7 +68,7 @@ namespace FlaxEngine.GUI
             var parentWin = target.Root;
             if (parentWin == null)
                 return;
-            float dpiScale = target.RootWindow.Window.DpiScale;
+            float dpiScale = target.RootWindow.DpiScale;
             Vector2 dpiSize = Size * dpiScale;
             Vector2 locationWS = target.PointToWindow(location);
             Vector2 locationSS = parentWin.PointToScreen(locationWS);

Source/Engine/UI/GUI/WindowRootControl.cs

@@ -55,6 +55,11 @@ namespace FlaxEngine.GUI
         /// </summary>
         public bool IsMaximized => _window.IsMaximized;
 
+        /// <summary>
+        /// Gets the window DPI scale factor (1 is default). Includes custom DPI scale
+        /// </summary>
+        public float DpiScale => _window.DpiScale;
+
         internal WindowRootControl(Window window)
         {
             _window = window;