Hide cursor and render the placeholder directly

OpenRA.Game/Orders/IOrderGenerator.cs

@@ -21,5 +21,6 @@ namespace OpenRA
 		IEnumerable<IRenderable> Render(WorldRenderer wr, World world);
 		IEnumerable<IRenderable> RenderAboveShroud(WorldRenderer wr, World world);
 		string GetCursor(World world, CPos cell, int2 worldPixel, MouseInput mi);
+		void Deactivate();
 	}
 }

OpenRA.Game/Orders/UnitOrderGenerator.cs

@@ -84,6 +84,8 @@ namespace OpenRA.Orders
 			return cursorOrder != null ? cursorOrder.Cursor : (useSelect ? "select" : "default");
 		}
 
+		public void Deactivate() { }
+
 		// Used for classic mouse orders, determines whether or not action at xy is move or select
 		public virtual bool InputOverridesSelection(WorldRenderer wr, World world, int2 xy, MouseInput mi)
 		{

OpenRA.Game/World.cs

@@ -148,6 +148,9 @@ namespace OpenRA
 			set
 			{
 				Sync.AssertUnsynced("The current order generator may not be changed from synced code");
+				if (orderGenerator != null)
+					orderGenerator.Deactivate();
+
 				orderGenerator = value;
 			}
 		}
@@ -544,6 +547,9 @@ namespace OpenRA
 		{
 			Disposing = true;
 
+			if (OrderGenerator != null)
+				OrderGenerator.Deactivate();
+
 			frameEndActions.Clear();
 
 			Game.Sound.StopAudio();