Add UpgradeActorsNear trait for passive upgrades.

OpenRA.Mods.RA/OpenRA.Mods.RA.csproj

@@ -550,6 +550,7 @@
     <Compile Include="Warheads\GrantUpgradeWarhead.cs" />
     <Compile Include="Crates\GrantUpgradeCrateAction.cs" />
     <Compile Include="Scripting\Properties\UpgradeProperties.cs" />
+    <Compile Include="UpgradeActorsNear.cs" />
     <Compile Include="WithRangeCircle.cs" />
   </ItemGroup>
   <ItemGroup>

OpenRA.Mods.RA/UpgradeActorsNear.cs

@@ -0,0 +1,117 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2014 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;
+using System.Collections.Generic;
+using OpenRA.GameRules;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.RA
+{
+	[Desc("Applies an upgrade to actors within a specified range.")]
+	public class UpgradeActorsNearInfo : ITraitInfo
+	{
+		[Desc("The upgrades to grant.")]
+		public readonly string[] Upgrades = { };
+
+		[Desc("The range to search for actors to upgrade.")]
+		public readonly WRange Range = WRange.FromCells(3);
+
+		[Desc("What diplomatic stances are affected.")]
+		public readonly Stance ValidStances = Stance.Ally;
+
+		[Desc("Grant the upgrades apply to this actor.")]
+		public readonly bool AffectsParent = false;
+
+		public readonly string EnableSound = null;
+		public readonly string DisableSound = null;
+
+		public object Create(ActorInitializer init) { return new UpgradeActorsNear(init.self, this); }
+	}
+
+	public class UpgradeActorsNear : ITick, INotifyAddedToWorld, INotifyRemovedFromWorld
+	{
+		readonly UpgradeActorsNearInfo info;
+		readonly Actor self;
+
+		int proximityTrigger;
+		WPos cachedPosition;
+		WRange cachedRange;
+		WRange desiredRange;
+
+		bool cachedDisabled = true;
+
+		public UpgradeActorsNear(Actor self, UpgradeActorsNearInfo info)
+		{
+			this.info = info;
+			this.self = self;
+			cachedRange = info.Range;
+		}
+
+		public void AddedToWorld(Actor self)
+		{
+			cachedPosition = self.CenterPosition;
+			proximityTrigger = self.World.ActorMap.AddProximityTrigger(cachedPosition, cachedRange, ActorEntered, ActorExited);
+		}
+
+		public void RemovedFromWorld(Actor self)
+		{
+			self.World.ActorMap.RemoveProximityTrigger(proximityTrigger);
+		}
+
+		public void Tick(Actor self)
+		{
+			var disabled = self.IsDisabled();
+
+			if (cachedDisabled != disabled)
+			{
+				Sound.Play(disabled ? info.DisableSound : info.EnableSound, self.CenterPosition);
+				desiredRange = disabled ? WRange.Zero : info.Range;
+				cachedDisabled = disabled;
+			}
+
+			if (self.CenterPosition != cachedPosition || desiredRange != cachedRange)
+			{
+				cachedPosition = self.CenterPosition;
+				cachedRange = desiredRange;
+				self.World.ActorMap.UpdateProximityTrigger(proximityTrigger, cachedPosition, cachedRange);
+			}
+		}
+
+		void ActorEntered(Actor a)
+		{
+			if (a.Destroyed)
+				return;
+
+			if (a == self && !info.AffectsParent)
+				return;
+
+			var stance = self.Owner.Stances[a.Owner];
+			if (!info.ValidStances.HasFlag(stance))
+				return;
+
+			var um = a.TraitOrDefault<UpgradeManager>();
+			if (um != null)
+				foreach (var u in info.Upgrades)
+					um.GrantUpgrade(a, u, this);
+		}
+
+		void ActorExited(Actor a)
+		{
+			if (a == self || a.Destroyed)
+				return;
+
+			var um = a.TraitOrDefault<UpgradeManager>();
+			if (um != null)
+				foreach (var u in info.Upgrades)
+					um.RevokeUpgrade(a, u, this);
+		}
+	}
+}