Add the ability to quickly change window modes for the game window.

Source/Editor/Options/InterfaceOptions.cs

@@ -90,6 +90,32 @@ namespace FlaxEditor.Options
             PlayScenes,
         }
 
+        /// <summary>
+        /// Available window modes for the game window.
+        /// </summary>
+        public enum GameWindowMode
+        {
+            /// <summary>
+            /// Shows the game window docked, inside the editor.
+            /// </summary>
+            Docked,
+
+            /// <summary>
+            /// Shows the game window as a popup.
+            /// </summary>
+            PopupWindow,
+
+            /// <summary>
+            /// Shows the game window maximized. (Same as pressing F11)
+            /// </summary>
+            MaximizedWindow,
+
+            /// <summary>
+            /// Shows the game window borderless.
+            /// </summary>
+            BorderlessWindow,
+        }
+
         /// <summary>
         /// Gets or sets the Editor User Interface scale. Applied to all UI elements, windows and text. Can be used to scale the interface up on a bigger display. Editor restart required.
         /// </summary>
@@ -229,6 +255,13 @@ namespace FlaxEditor.Options
         [EditorDisplay("Play In-Editor", "Play Button Action"), EditorOrder(410)]
         public PlayAction PlayButtonAction { get; set; } = PlayAction.PlayScenes;
 
+        /// <summary>
+        /// Gets or sets a value indicating how the game window should be displayed when the game is launched.
+        /// </summary>
+        [DefaultValue(GameWindowMode.Docked)]
+        [EditorDisplay("Play In-Editor", "Game Window Mode"), EditorOrder(420), Tooltip("Determines how the game window is displayed when the game is launched.")]
+        public GameWindowMode DefaultGameWindowMode { get; set; } = GameWindowMode.Docked;
+
         /// <summary>
         /// Gets or sets a value indicating the number of game clients to launch when building and/or running cooked game.
         /// </summary>