use new Enter activity for engy, spy, c4

OpenRA.Mods.RA/Activities/MoveAdjacentTo.cs

@@ -0,0 +1,54 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2010 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made 
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation. For more information,
+ * see LICENSE.
+ */
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using OpenRA.Traits;
+using OpenRA.Traits.Activities;
+
+namespace OpenRA.Mods.RA.Activities
+{
+	public class MoveAdjacentTo : CancelableActivity
+	{
+		readonly Actor target;
+
+		public MoveAdjacentTo( Actor target )
+		{
+			this.target = target;
+		}
+
+		public override IActivity Tick( Actor self )
+		{
+			if( IsCanceled || target.Destroyed || !target.IsInWorld) return NextActivity;
+
+			var mobile = self.Trait<Mobile>();
+			var ps1 = new PathSearch( self.World, mobile.Info )
+			{
+				checkForBlocked = true,
+				heuristic = location => 0,
+				inReverse = true
+			};
+			foreach( var cell in target.Trait<IOccupySpace>().OccupiedCells() )
+			{
+				ps1.AddInitialCell( cell );
+				if( ( mobile.toCell - cell ).LengthSquared <= 2 )
+					return NextActivity;
+			}
+			ps1.heuristic = PathSearch.DefaultEstimator( mobile.toCell );
+
+			var ps2 = PathSearch.FromPoint( self.World, mobile.Info, mobile.toCell, target.Location, true );
+			var ret = self.World.PathFinder.FindBidiPath( ps1, ps2 );
+			if( ret.Count > 0 )
+				ret.RemoveAt( 0 );
+			return Util.SequenceActivities( new Move( () => ret ), this );
+		}
+	}
+}