move HiddenUnderFog, WithMuzzleFlash into modifiers where they belong

OpenRA.Game/Traits/Modifiers/HiddenUnderFog.cs

@@ -0,0 +1,48 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007,2009,2010 Chris Forbes, Robert Pepperell, Matthew Bowra-Dean, Paul Chote, Alli Witheford.
+ * This file is part of OpenRA.
+ * 
+ *  OpenRA is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ * 
+ *  OpenRA is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ * 
+ *  You should have received a copy of the GNU General Public License
+ *  along with OpenRA.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#endregion
+
+using System.Collections.Generic;
+
+namespace OpenRA.Traits.Render
+{
+	class HiddenUnderFogInfo : ITraitInfo
+	{
+		public object Create(Actor self) { return new HiddenUnderFog(self); }
+	}
+
+	class HiddenUnderFog : IRenderModifier
+	{
+		Shroud shroud;
+
+		public HiddenUnderFog(Actor self)
+		{
+			shroud = self.World.WorldActor.traits.Get<Shroud>();
+		}
+
+		static Renderable[] Nothing = { };
+		public IEnumerable<Renderable> ModifyRender(Actor self, IEnumerable<Renderable> r)
+		{
+			if (self.World.LocalPlayer == null || self.Owner == self.World.LocalPlayer || shroud.visibleCells[self.Location.X, self.Location.Y] > 0)
+				return r;
+			else
+				return Nothing;
+		}
+	}
+}