Pull ActorMap back out into a trait.

OpenRA.Game/Traits/World/ActorMap.cs

@@ -0,0 +1,130 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2011 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 COPYING.
+ */
+#endregion
+
+using System.Collections.Generic;
+using System.Linq;
+using OpenRA.Traits;
+
+namespace OpenRA.Traits
+{
+	public enum SubCell { FullCell, TopLeft, TopRight, Center, BottomLeft, BottomRight }
+
+	class ActorMapInfo : ITraitInfo
+	{
+		public object Create(ActorInitializer init) { return new ActorMap(init.world); }
+	}
+
+	public class ActorMap
+	{
+		class InfluenceNode
+		{
+			public InfluenceNode next;
+			public SubCell subCell;
+			public Actor actor;
+		}
+
+		InfluenceNode[,] influence;
+		Map map;
+
+		public ActorMap(World world)
+		{
+			map = world.Map;
+			influence = new InfluenceNode[world.Map.MapSize.X, world.Map.MapSize.Y];
+
+			world.ActorAdded += a => Add(a, a.OccupiesSpace);
+			world.ActorRemoved += a => Remove(a, a.OccupiesSpace);
+		}
+
+		public IEnumerable<Actor> GetUnitsAt(CPos a)
+		{
+			if (!map.IsInMap(a))
+				yield break;
+
+			for (var i = influence[a.X, a.Y]; i != null; i = i.next)
+				if (!i.actor.Destroyed)
+					yield return i.actor;
+		}
+
+		public IEnumerable<Actor> GetUnitsAt(CPos a, SubCell sub)
+		{
+			if (!map.IsInMap(a))
+				yield break;
+
+			for (var i = influence[a.X, a.Y]; i != null; i = i.next)
+				if (!i.actor.Destroyed && (i.subCell == sub || i.subCell == SubCell.FullCell))
+					yield return i.actor;
+		}
+
+		public bool HasFreeSubCell(CPos a)
+		{
+			if (!AnyUnitsAt(a))
+				return true;
+
+			return new[] { SubCell.TopLeft, SubCell.TopRight, SubCell.Center,
+				SubCell.BottomLeft, SubCell.BottomRight }.Any(b => !AnyUnitsAt(a,b));
+		}
+
+		public SubCell? FreeSubCell(CPos a)
+		{
+			if (!HasFreeSubCell(a))
+				return null;
+
+			return new[] { SubCell.TopLeft, SubCell.TopRight, SubCell.Center,
+				SubCell.BottomLeft, SubCell.BottomRight }.First(b => !AnyUnitsAt(a,b));
+		}
+
+
+		public bool AnyUnitsAt(CPos a)
+		{
+			return influence[a.X, a.Y] != null;
+		}
+
+		public bool AnyUnitsAt(CPos a, SubCell sub)
+		{
+			for (var i = influence[a.X, a.Y]; i != null; i = i.next)
+				if (i.subCell == sub || i.subCell == SubCell.FullCell)
+					return true;
+
+			return false;
+		}
+
+		public void Add(Actor self, IOccupySpace unit)
+		{
+			if (unit != null)
+				foreach (var c in unit.OccupiedCells())
+					influence[c.First.X, c.First.Y] = new InfluenceNode { next = influence[c.First.X, c.First.Y], subCell = c.Second, actor = self };
+		}
+
+		public void Remove(Actor self, IOccupySpace unit)
+		{
+			if (unit != null)
+				foreach (var c in unit.OccupiedCells())
+					RemoveInner(ref influence[c.First.X, c.First.Y], self);
+		}
+
+		void RemoveInner(ref InfluenceNode influenceNode, Actor toRemove)
+		{
+			if (influenceNode == null)
+				return;
+			else if (influenceNode.actor == toRemove)
+				influenceNode = influenceNode.next;
+
+			if (influenceNode != null)
+				RemoveInner(ref influenceNode.next, toRemove);
+		}
+
+		public void Update(Actor self, IOccupySpace unit)
+		{
+			Remove(self, unit);
+			if (!self.IsDead())
+				Add(self, unit);
+		}
+	}
+}