Moves some misc traits/activities to Mods.Common, moves some RA traits into the Traits folder

OpenRA.Mods.RA/Traits/ParaDrop.cs

@@ -0,0 +1,101 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2015 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.Mods.Common.Traits;
+using OpenRA.Mods.RA.Activities;
+using OpenRA.Mods.RA.Effects;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.RA.Traits
+{
+	[Desc("This unit can spawn and eject other actors while flying.")]
+	public class ParaDropInfo : ITraitInfo, Requires<CargoInfo>
+	{
+		[Desc("Distance around the drop-point to unload troops.")]
+		public readonly WRange DropRange = WRange.FromCells(4);
+
+		[Desc("Sound to play when dropping.")]
+		public readonly string ChuteSound = "chute1.aud";
+
+		public object Create(ActorInitializer init) { return new ParaDrop(init.Self, this); }
+	}
+
+	public class ParaDrop : ITick, INotifyRemovedFromWorld
+	{
+		readonly ParaDropInfo info;
+		readonly Actor self;
+		readonly Cargo cargo;
+		readonly HashSet<CPos> droppedAt = new HashSet<CPos>();
+
+		public event Action<Actor> OnRemovedFromWorld = self => { };
+		public event Action<Actor> OnEnteredDropRange = self => { };
+		public event Action<Actor> OnExitedDropRange = self => { };
+
+		[Sync] bool inDropRange;
+		[Sync] Target target;
+
+		bool checkForSuitableCell;
+
+		public ParaDrop(Actor self, ParaDropInfo info)
+		{
+			this.info = info;
+			this.self = self;
+			cargo = self.Trait<Cargo>();
+		}
+
+		public void SetLZ(CPos lz, bool checkLandingCell)
+		{
+			droppedAt.Clear();
+			target = Target.FromCell(self.World, lz);
+			checkForSuitableCell = checkLandingCell;
+		}
+
+		public void Tick(Actor self)
+		{
+			var wasInDropRange = inDropRange;
+			inDropRange = target.IsInRange(self.CenterPosition, info.DropRange);
+
+			if (inDropRange && !wasInDropRange)
+				OnEnteredDropRange(self);
+
+			if (!inDropRange && wasInDropRange)
+				OnExitedDropRange(self);
+
+			// Are we able to drop the next trooper?
+			if (!inDropRange || cargo.IsEmpty(self))
+				return;
+
+			if (droppedAt.Contains(self.Location) || (checkForSuitableCell && !IsSuitableCell(cargo.Peek(self), self.Location)))
+				return;
+
+			if (!self.World.Map.Contains(self.Location))
+				return;
+
+			// unload a dude here
+			droppedAt.Add(self.Location);
+
+			var a = cargo.Unload(self);
+			self.World.AddFrameEndTask(w => w.Add(new Parachute(a, self.CenterPosition)));
+			Sound.Play(info.ChuteSound, self.CenterPosition);
+		}
+
+		static bool IsSuitableCell(Actor actorToDrop, CPos p)
+		{
+			return actorToDrop.Trait<IPositionable>().CanEnterCell(p);
+		}
+
+		public void RemovedFromWorld(Actor self)
+		{
+			OnRemovedFromWorld(self);
+		}
+	}
+}