Add RevealOnDeath trait

Allows revealing shroud on actor death.

OpenRA.Mods.Common/OpenRA.Mods.Common.csproj

@@ -787,6 +787,7 @@
     <Compile Include="UtilityCommands\Utilities.cs" />
     <Compile Include="UtilityCommands\OutputResolvedSequencesCommand.cs" />
     <Compile Include="UtilityCommands\OutputResolvedWeaponsCommand.cs" />
+    <Compile Include="Traits\RevealOnDeath.cs" />
     <Compile Include="Traits\RevealOnFire.cs" />
     <Compile Include="Traits\Conditions\GrantConditionOnDisabled.cs" />
     <Compile Include="Traits\World\ActorMap.cs" />

OpenRA.Mods.Common/Traits/RevealOnDeath.cs

@@ -0,0 +1,70 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2017 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.Linq;
+using OpenRA.Mods.Common.Effects;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Traits
+{
+	[Desc("Reveal this actor's last position when killed.")]
+	public class RevealOnDeathInfo : ConditionalTraitInfo
+	{
+		[Desc("Stances relative to the actors' owner that shroud will be revealed for.")]
+		public readonly Stance RevealForStances = Stance.Ally;
+
+		[Desc("Duration of the reveal.")]
+		public readonly int Duration = 25;
+
+		[Desc("Radius of the reveal around this actor.")]
+		public readonly WDist Radius = new WDist(1536);
+
+		[Desc("Can this actor be revealed through shroud generated by the GeneratesShroud trait?")]
+		public readonly bool RevealGeneratedShroud = true;
+
+		public override object Create(ActorInitializer init) { return new RevealOnDeath(init.Self, this); }
+	}
+
+	public class RevealOnDeath : ConditionalTrait<RevealOnDeathInfo>, INotifyKilled
+	{
+		readonly RevealOnDeathInfo info;
+
+		public RevealOnDeath(Actor self, RevealOnDeathInfo info)
+			: base(info)
+		{
+			this.info = info;
+		}
+
+		void INotifyKilled.Killed(Actor self, AttackInfo attack)
+		{
+			if (IsTraitDisabled)
+				return;
+
+			if (!self.IsInWorld)
+				return;
+
+			var owner = self.Owner;
+			if (owner != null && owner.WinState == WinState.Undefined)
+			{
+				self.World.AddFrameEndTask(w =>
+				{
+					// Actor has been disposed by something else before its death (for example `Enter`).
+					if (self.Disposed)
+						return;
+
+					w.Add(new RevealShroudEffect(self.CenterPosition, info.Radius,
+						info.RevealGeneratedShroud ? Shroud.SourceType.Visibility : Shroud.SourceType.PassiveVisibility,
+						owner, info.RevealForStances, duration: info.Duration));
+				});
+			}
+		}
+	}
+}