Add CellTrigger support to ProximityCapturable

OpenRA.Mods.Common/Traits/RegionProximityCapturable.cs

@@ -0,0 +1,63 @@
+#region Copyright & License Information
+/*
+ * Copyright (c) The OpenRA Developers and Contributors
+ * 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, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace OpenRA.Mods.Common.Traits
+{
+	[Desc("Actor can be captured by units entering a certain set of cells.")]
+	public class RegionProximityCapturableInfo : ProximityCapturableBaseInfo
+	{
+		[Desc("Set of cell offsets (relative to the actor's Location) the " + nameof(ProximityCaptor) + " needs to be in to initiate the capture. ",
+			"A 'Region' ActorInit can be used to override this value per actor. If either is empty or non-existent, ",
+			"the immediately neighboring cells of the actor will be used.")]
+		public readonly CVec[] Region = Array.Empty<CVec>();
+
+		public override object Create(ActorInitializer init) { return new RegionProximityCapturable(init, this); }
+	}
+
+	public class RegionProximityCapturable : ProximityCapturableBase
+	{
+		readonly CVec[] offsets;
+		CPos[] region;
+
+		public RegionProximityCapturable(ActorInitializer init, RegionProximityCapturableInfo info)
+			: base(init, info)
+		{
+			offsets = init.GetValue<RegionInit, CVec[]>(info, info.Region);
+		}
+
+		protected override int CreateTrigger(Actor self)
+		{
+			region = offsets.Select(o => o + self.Location).ToArray();
+
+			if (region.Length == 0)
+				region = Util.ExpandFootprint(new List<CPos> { self.Location }, true).ToArray();
+
+			return self.World.ActorMap.AddCellTrigger(region, ActorEntered, ActorLeft);
+		}
+
+		protected override void RemoveTrigger(Actor self, int trigger)
+		{
+			self.World.ActorMap.RemoveCellTrigger(trigger);
+		}
+
+		protected override void TickInner(Actor self) { }
+	}
+
+	public class RegionInit : ValueActorInit<CVec[]>
+	{
+		public RegionInit(CVec[] value)
+			: base(value) { }
+	}
+}