Add dedicated TDGunboat traits

And get rid of Mobile.OnRails hack.

OpenRA.Mods.Cnc/Traits/Attack/AttackTDGunboatTurreted.cs

@@ -0,0 +1,73 @@
+#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.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Cnc.Traits
+{
+	[Desc("Actor has a visual turret used to attack.")]
+	public class AttackTDGunboatTurretedInfo : AttackTurretedInfo, Requires<TDGunboatInfo>
+	{
+		public override object Create(ActorInitializer init) { return new AttackTDGunboatTurreted(init.Self, this); }
+	}
+
+	public class AttackTDGunboatTurreted : AttackTurreted
+	{
+		public AttackTDGunboatTurreted(Actor self, AttackTDGunboatTurretedInfo info)
+			: base(self, info) { }
+
+		public override Activity GetAttackActivity(Actor self, Target newTarget, bool allowMove, bool forceAttack)
+		{
+			return new AttackTDGunboatTurretedActivity(self, newTarget, allowMove, forceAttack);
+		}
+
+		class AttackTDGunboatTurretedActivity : Activity
+		{
+			readonly AttackTDGunboatTurreted attack;
+			readonly Target target;
+			readonly bool forceAttack;
+			bool hasTicked;
+
+			public AttackTDGunboatTurretedActivity(Actor self, Target target, bool allowMove, bool forceAttack)
+			{
+				attack = self.Trait<AttackTDGunboatTurreted>();
+				this.target = target;
+				this.forceAttack = forceAttack;
+			}
+
+			public override Activity Tick(Actor self)
+			{
+				if (IsCanceled || !target.IsValidFor(self))
+					return NextActivity;
+
+				if (attack.IsTraitDisabled)
+					return this;
+
+				var weapon = attack.ChooseArmamentsForTarget(target, forceAttack).FirstOrDefault();
+				if (weapon != null)
+				{
+					// Check that AttackTDGunboatTurreted hasn't cancelled the target by modifying attack.Target
+					// Having both this and AttackTDGunboatTurreted modify that field is a horrible hack.
+					if (hasTicked && attack.Target.Type == TargetType.Invalid)
+						return NextActivity;
+
+					attack.Target = target;
+					hasTicked = true;
+				}
+
+				return NextActivity;
+			}
+		}
+	}
+}