Split CarryUnit into PickupUnit and DeliverUnit

OpenRA.Mods.D2k/Activities/DeliverUnit.cs

@@ -0,0 +1,140 @@
+#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 OpenRA.Activities;
+using OpenRA.Mods.Common.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Mods.D2k.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.D2k.Activities
+{
+	public class DeliverUnit : Activity
+	{
+		readonly Actor self;
+		readonly Actor cargo;
+		readonly IMove movement;
+		readonly Carryable carryable;
+		readonly Carryall carryall;
+		readonly Helicopter helicopter;
+		readonly IPositionable positionable;
+		readonly IFacing cargoFacing;
+		readonly IFacing selfFacing;
+
+		enum State { Transport, Land, Release, Done }
+
+		State state;
+
+		public DeliverUnit(Actor self)
+		{
+			carryall = self.Trait<Carryall>();
+			this.self = self;
+			cargo = carryall.Carrying;
+			movement = self.Trait<IMove>();
+			carryable = cargo.Trait<Carryable>();
+			helicopter = self.Trait<Helicopter>();
+			positionable = cargo.Trait<IPositionable>();
+			cargoFacing = cargo.Trait<IFacing>();
+			selfFacing = self.Trait<IFacing>();
+			state = State.Transport;
+		}
+
+		// Find a suitable location to drop our carryable
+		CPos GetLocationToDrop(CPos requestedPosition)
+		{
+			if (positionable.CanEnterCell(requestedPosition))
+				return requestedPosition;
+
+			var candidateCells = Util.AdjacentCells(self.World, Target.FromCell(self.World, requestedPosition));
+
+			// TODO: This will behave badly if there is no suitable drop point nearby
+			do
+			{
+				foreach (var c in candidateCells)
+					if (positionable.CanEnterCell(c))
+						return c;
+
+				// Expanding dropable cells search area
+				// TODO: This also includes all of the cells we have just checked
+				candidateCells = Util.ExpandFootprint(candidateCells, true);
+			} while (true);
+		}
+
+		// Check if we can drop the unit at our current location.
+		bool CanDropHere()
+		{
+			return positionable.CanEnterCell(self.Location);
+		}
+
+		public override Activity Tick(Actor self)
+		{
+			if (cargo.IsDead || !carryall.IsBusy)
+			{
+				carryall.UnreserveCarryable();
+				return NextActivity;
+			}
+
+			switch (state)
+			{
+				case State.Transport:
+					var targetl = GetLocationToDrop(carryable.Destination);
+					state = State.Land;
+					return Util.SequenceActivities(movement.MoveTo(targetl, 0), this);
+
+				case State.Land:
+					if (!CanDropHere())
+					{
+						state = State.Transport;
+						return this;
+					}
+
+					if (HeliFly.AdjustAltitude(self, helicopter, helicopter.Info.LandAltitude))
+						return this;
+					state = State.Release;
+					return Util.SequenceActivities(new Wait(15), this);
+
+				case State.Release:
+					if (!CanDropHere())
+					{
+						state = State.Transport;
+						return this;
+					}
+
+					Release();
+					state = State.Done;
+					return Util.SequenceActivities(new Wait(10), this);
+
+				case State.Done:
+					self.Trait<Carryall>().UnreserveCarryable();
+					return NextActivity;
+			}
+
+			return NextActivity;
+		}
+
+		void Release()
+		{
+			positionable.SetPosition(cargo, self.Location, SubCell.FullCell);
+			cargoFacing.Facing = selfFacing.Facing;
+
+			// Put back into world
+			self.World.AddFrameEndTask(w => cargo.World.Add(cargo));
+
+			// Unlock carryable
+			carryall.CarryableReleased();
+			carryable.Dropped();
+		}
+
+		public override void Cancel(Actor self)
+		{
+			// TODO: Drop the unit at the nearest available cell
+		}
+	}
+}