Generalize WormManager into ActorSpawnManager.

Added support of multiple actors, conditions and types.

OpenRA.Mods.Common/Traits/World/ActorSpawnManager.cs

@@ -0,0 +1,116 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2018 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, 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;
+using OpenRA.Primitives;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Traits
+{
+	[Desc("Controls the spawning of specified actor types. Attach this to the world actor.")]
+	public class ActorSpawnManagerInfo : ConditionalTraitInfo, Requires<MapCreepsInfo>
+	{
+		[Desc("Minimum number of actors.")]
+		public readonly int Minimum = 0;
+
+		[Desc("Maximum number of actors.")]
+		public readonly int Maximum = 4;
+
+		[Desc("Time (in ticks) between actor spawn.")]
+		public readonly int SpawnInterval = 6000;
+
+		[FieldLoader.Require]
+		[ActorReference]
+		[Desc("Name of the actor that will be randomly picked to spawn.")]
+		public readonly string[] Actors = { };
+
+		public readonly string Owner = "Creeps";
+
+		[Desc("Type of ActorSpawner with which it connects.")]
+ 		public readonly HashSet<string> Types = new HashSet<string>() { };
+
+		public override object Create(ActorInitializer init) { return new ActorSpawnManager(init.Self, this); }
+	}
+
+	public class ActorSpawnManager : ConditionalTrait<ActorSpawnManagerInfo>, ITick, INotifyCreated
+	{
+		readonly ActorSpawnManagerInfo info;
+		TraitPair<ActorSpawner>[] spawnPointActors;
+
+		bool enabled;
+		int spawnCountdown;
+		int actorsPresent;
+
+		public ActorSpawnManager(Actor self, ActorSpawnManagerInfo info) : base(info)
+		{
+			this.info = info;
+		}
+
+		void INotifyCreated.Created(Actor self)
+		{
+			self.World.AddFrameEndTask(w =>
+			{
+				spawnPointActors = w.ActorsWithTrait<ActorSpawner>()
+					.Where(x => info.Types.Overlaps(x.Trait.Types) || !x.Trait.Types.Any())
+					.ToArray();
+
+				enabled = self.Trait<MapCreeps>().Enabled && spawnPointActors.Any();
+			});
+		}
+
+		void ITick.Tick(Actor self)
+		{
+			if (IsTraitDisabled || !enabled)
+				return;
+
+			if (info.Maximum < 1 || actorsPresent >= info.Maximum)
+				return;
+
+			if (--spawnCountdown > 0 && actorsPresent >= info.Minimum)
+				return;
+
+			spawnCountdown = info.SpawnInterval;
+
+			do
+			{
+				// Always spawn at least one actor, plus
+				// however many needed to reach the minimum.
+				SpawnActor(self);
+			} while (actorsPresent < info.Minimum);
+		}
+
+		WPos SpawnActor(Actor self)
+		{
+			var spawnPoint = GetRandomSpawnPoint(self.World.SharedRandom);
+			self.World.AddFrameEndTask(w => w.CreateActor(info.Actors.Random(self.World.SharedRandom), new TypeDictionary
+			{
+				new OwnerInit(w.Players.First(x => x.PlayerName == info.Owner)),
+				new LocationInit(spawnPoint.Location)
+			}));
+
+			actorsPresent++;
+
+			return spawnPoint.CenterPosition;
+		}
+
+		Actor GetRandomSpawnPoint(Support.MersenneTwister random)
+		{
+			return spawnPointActors.Random(random).Actor;
+		}
+
+		public void DecreaseActorCount()
+		{
+			actorsPresent--;
+		}
+	}
+}