Moves Attack, Armament, Move, Air traits and activities as well as anything required by them to Mods.Common.

Extracts Exit from Production into its own trait.

OpenRA.Mods.Common/Activities/Air/FallToEarth.cs

@@ -0,0 +1,65 @@
+#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.Linq;
+using OpenRA.Activities;
+using OpenRA.GameRules;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class FallToEarth : Activity
+	{
+		int acceleration = 0;
+		int spin = 0;
+		FallsToEarthInfo info;
+
+		public FallToEarth(Actor self, FallsToEarthInfo info)
+		{
+			this.info = info;
+			if (info.Spins)
+				acceleration = self.World.SharedRandom.Next(2) * 2 - 1;
+		}
+
+		public override Activity Tick(Actor self)
+		{
+			var aircraft = self.Trait<Aircraft>();
+			if (self.CenterPosition.Z <= 0)
+			{
+				if (info.Explosion != null)
+				{
+					var weapon = self.World.Map.Rules.Weapons[info.Explosion.ToLowerInvariant()];
+
+					// Use .FromPos since this actor is killed. Cannot use Target.FromActor
+					weapon.Impact(Target.FromPos(self.CenterPosition), self, Enumerable.Empty<int>());
+				}
+
+				self.Destroy();
+				return null;
+			}
+
+			if (info.Spins)
+			{
+				spin += acceleration;
+				aircraft.Facing = (aircraft.Facing + spin) % 256;
+			}
+
+			var move = info.Moves ? aircraft.FlyStep(aircraft.Facing) : WVec.Zero;
+			move -= new WVec(WRange.Zero, WRange.Zero, info.Velocity);
+			aircraft.SetPosition(self, aircraft.CenterPosition + move);
+
+			return this;
+		}
+
+		// Cannot be cancelled
+		public override void Cancel(Actor self) { }
+	}
+}

OpenRA.Mods.Common/Activities/Air/Fly.cs

@@ -0,0 +1,87 @@
+#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.Collections.Generic;
+using OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class Fly : Activity
+	{
+		readonly Plane plane;
+		readonly Target target;
+		readonly WRange maxRange;
+		readonly WRange minRange;
+
+		public Fly(Actor self, Target t)
+		{
+			plane = self.Trait<Plane>();
+			target = t;
+		}
+
+		public Fly(Actor self, Target t, WRange minRange, WRange maxRange)
+			: this(self, t)
+		{
+			this.maxRange = maxRange;
+			this.minRange = minRange;
+		}
+
+		public static void FlyToward(Actor self, Plane plane, int desiredFacing, WRange desiredAltitude)
+		{
+			var move = plane.FlyStep(plane.Facing);
+			var altitude = plane.CenterPosition.Z;
+
+			plane.Facing = Util.TickFacing(plane.Facing, desiredFacing, plane.ROT);
+
+			if (altitude != desiredAltitude.Range)
+			{
+				var delta = move.HorizontalLength * plane.Info.MaximumPitch.Tan() / 1024;
+				var dz = (desiredAltitude.Range - altitude).Clamp(-delta, delta);
+				move += new WVec(0, 0, dz);
+			}
+
+			plane.SetPosition(self, plane.CenterPosition + move);
+		}
+
+		public override Activity Tick(Actor self)
+		{
+			if (IsCanceled || !target.IsValidFor(self))
+				return NextActivity;
+
+			// Inside the target annulus, so we're done
+			var insideMaxRange = maxRange.Range > 0 && target.IsInRange(plane.CenterPosition, maxRange);
+			var insideMinRange = minRange.Range > 0 && target.IsInRange(plane.CenterPosition, minRange);
+			if (insideMaxRange && !insideMinRange)
+				return NextActivity;
+
+			// Close enough (ported from old code which checked length against sqrt(50) px)
+			var d = target.CenterPosition - self.CenterPosition;
+			if (d.HorizontalLengthSquared < 91022)
+				return NextActivity;
+
+			var desiredFacing = Util.GetFacing(d, plane.Facing);
+
+			// Don't turn until we've reached the cruise altitude
+			if (plane.CenterPosition.Z < plane.Info.CruiseAltitude.Range)
+				desiredFacing = plane.Facing;
+
+			FlyToward(self, plane, desiredFacing, plane.Info.CruiseAltitude);
+
+			return this;
+		}
+
+		public override IEnumerable<Target> GetTargets(Actor self)
+		{
+			yield return target;
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Air/FlyAttack.cs

@@ -0,0 +1,64 @@
+#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.Linq;
+using OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class FlyAttack : Activity
+	{
+		readonly Target target;
+		Activity inner;
+		int ticksUntilTurn = 50;
+
+		public FlyAttack(Target target) { this.target = target; }
+
+		public override Activity Tick(Actor self)
+		{
+			if (!target.IsValidFor(self))
+				return NextActivity;
+
+			var limitedAmmo = self.TraitOrDefault<LimitedAmmo>();
+			if (limitedAmmo != null && !limitedAmmo.HasAmmo())
+				return NextActivity;
+
+			var attack = self.TraitOrDefault<AttackPlane>();
+			if (attack != null)
+				attack.DoAttack(self, target);
+
+			if (inner == null)
+			{
+				if (IsCanceled)
+					return NextActivity;
+
+				if (target.IsInRange(self.CenterPosition, attack.Armaments.Select(a => a.Weapon.MinRange).Min()))
+					inner = Util.SequenceActivities(new FlyTimed(ticksUntilTurn), new Fly(self, target), new FlyTimed(ticksUntilTurn));
+				else
+					inner = Util.SequenceActivities(new Fly(self, target), new FlyTimed(ticksUntilTurn));
+			}
+
+			inner = Util.RunActivity(self, inner);
+
+			return this;
+		}
+
+		public override void Cancel(Actor self)
+		{
+			if (!IsCanceled && inner != null)
+				inner.Cancel(self);
+
+			// NextActivity must always be set to null:
+			base.Cancel(self);
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Air/FlyCircle.cs

@@ -0,0 +1,33 @@
+#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 OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class FlyCircle : Activity
+	{
+		public override Activity Tick(Actor self)
+		{
+			if (IsCanceled)
+				return NextActivity;
+
+			var plane = self.Trait<Plane>();
+
+			// We can't possibly turn this fast
+			var desiredFacing = plane.Facing + 64;
+			Fly.FlyToward(self, plane, desiredFacing, plane.Info.CruiseAltitude);
+
+			return this;
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Air/FlyFollow.cs

@@ -0,0 +1,46 @@
+#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 OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class FlyFollow : Activity
+	{
+		Target target;
+		Plane plane;
+		WRange minRange;
+		WRange maxRange;
+
+		public FlyFollow(Actor self, Target target, WRange minRange, WRange maxRange)
+		{
+			this.target = target;
+			plane = self.Trait<Plane>();
+			this.minRange = minRange;
+			this.maxRange = maxRange;
+		}
+
+		public override Activity Tick(Actor self)
+		{
+			if (IsCanceled || !target.IsValidFor(self))
+				return NextActivity;
+
+			if (target.IsInRange(self.CenterPosition, maxRange) && !target.IsInRange(self.CenterPosition, minRange))
+			{
+				Fly.FlyToward(self, plane, plane.Facing, plane.Info.CruiseAltitude);
+				return this;
+			}
+
+			return Util.SequenceActivities(new Fly(self, target, minRange, maxRange), this);
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Air/FlyTimed.cs

@@ -0,0 +1,52 @@
+#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 OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class FlyTimed : Activity
+	{
+		int remainingTicks;
+
+		public FlyTimed(int ticks) { remainingTicks = ticks; }
+
+		public override Activity Tick(Actor self)
+		{
+			if (IsCanceled || remainingTicks-- == 0)
+				return NextActivity;
+
+			var plane = self.Trait<Plane>();
+			Fly.FlyToward(self, plane, plane.Facing, plane.Info.CruiseAltitude);
+
+			return this;
+		}
+	}
+
+	public class FlyOffMap : Activity
+	{
+		public override Activity Tick(Actor self)
+		{
+			if (IsCanceled || !self.World.Map.Contains(self.Location))
+				return NextActivity;
+
+			var plane = self.Trait<Plane>();
+			Fly.FlyToward(self, plane, plane.Facing, plane.Info.CruiseAltitude);
+			return this;
+		}
+
+		public override void Cancel(Actor self)
+		{
+			base.Cancel(self);
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Air/HeliAttack.cs

@@ -0,0 +1,52 @@
+#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 OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class HeliAttack : Activity
+	{
+		Target target;
+		public HeliAttack(Target target) { this.target = target; }
+
+		public override Activity Tick(Actor self)
+		{
+			if (IsCanceled || !target.IsValidFor(self))
+				return NextActivity;
+
+			var limitedAmmo = self.TraitOrDefault<LimitedAmmo>();
+			var reloads = self.TraitOrDefault<Reloads>();
+			if (limitedAmmo != null && !limitedAmmo.HasAmmo() && reloads == null)
+				return Util.SequenceActivities(new HeliReturn(), NextActivity);
+
+			var helicopter = self.Trait<Helicopter>();
+			var attack = self.Trait<AttackHeli>();
+			var dist = target.CenterPosition - self.CenterPosition;
+
+			// Can rotate facing while ascending
+			var desiredFacing = Util.GetFacing(dist, helicopter.Facing);
+			helicopter.Facing = Util.TickFacing(helicopter.Facing, desiredFacing, helicopter.ROT);
+
+			if (HeliFly.AdjustAltitude(self, helicopter, helicopter.Info.CruiseAltitude))
+				return this;
+
+			// Fly towards the target
+			if (!target.IsInRange(self.CenterPosition, attack.GetMaximumRange()))
+				helicopter.SetPosition(self, helicopter.CenterPosition + helicopter.FlyStep(desiredFacing));
+
+			attack.DoAttack(self, target);
+
+			return this;
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Air/HeliFly.cs

@@ -0,0 +1,95 @@
+#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.Collections.Generic;
+using OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class HeliFly : Activity
+	{
+		readonly Helicopter helicopter;
+		readonly Target target;
+		readonly WRange maxRange;
+		readonly WRange minRange;
+
+		public HeliFly(Actor self, Target t)
+		{
+			helicopter = self.Trait<Helicopter>();
+			target = t;
+		}
+
+		public HeliFly(Actor self, Target t, WRange minRange, WRange maxRange)
+			: this(self, t)
+		{
+			this.maxRange = maxRange;
+			this.minRange = minRange;
+		}
+
+		public static bool AdjustAltitude(Actor self, Helicopter helicopter, WRange targetAltitude)
+		{
+			var altitude = helicopter.CenterPosition.Z;
+			if (altitude == targetAltitude.Range)
+				return false;
+
+			var delta = helicopter.Info.AltitudeVelocity.Range;
+			var dz = (targetAltitude.Range - altitude).Clamp(-delta, delta);
+			helicopter.SetPosition(self, helicopter.CenterPosition + new WVec(0, 0, dz));
+
+			return true;
+		}
+
+		public override Activity Tick(Actor self)
+		{
+			if (IsCanceled || !target.IsValidFor(self))
+				return NextActivity;
+
+			if (AdjustAltitude(self, helicopter, helicopter.Info.CruiseAltitude))
+				return this;
+
+			var pos = target.CenterPosition;
+
+			// Rotate towards the target
+			var dist = pos - self.CenterPosition;
+			var desiredFacing = Util.GetFacing(dist, helicopter.Facing);
+			helicopter.Facing = Util.TickFacing(helicopter.Facing, desiredFacing, helicopter.ROT);
+			var move = helicopter.FlyStep(desiredFacing);
+
+			// Inside the minimum range, so reverse
+			if (minRange.Range > 0 && target.IsInRange(helicopter.CenterPosition, minRange))
+			{
+				helicopter.SetPosition(self, helicopter.CenterPosition - move);
+				return this;
+			}
+
+			// Inside the maximum range, so we're done
+			if (maxRange.Range > 0 && target.IsInRange(helicopter.CenterPosition, maxRange))
+				return NextActivity;
+
+			// The next move would overshoot, so just set the final position
+			if (dist.HorizontalLengthSquared < move.HorizontalLengthSquared)
+			{
+				helicopter.SetPosition(self, pos + new WVec(0, 0, helicopter.Info.CruiseAltitude.Range - pos.Z));
+				return NextActivity;
+			}
+
+			helicopter.SetPosition(self, helicopter.CenterPosition + move);
+
+			return this;
+		}
+
+		public override IEnumerable<Target> GetTargets(Actor self)
+		{
+			yield return target;
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Air/HeliFlyCircle.cs

@@ -0,0 +1,45 @@
+#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.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class HeliFlyCircle : Activity
+	{
+		readonly Helicopter helicopter;
+
+		public HeliFlyCircle(Actor self)
+		{
+			helicopter = self.Trait<Helicopter>();
+		}
+
+		public override Activity Tick(Actor self)
+		{
+			if (IsCanceled)
+				return NextActivity;
+
+			if (HeliFly.AdjustAltitude(self, helicopter, helicopter.Info.CruiseAltitude))
+				return this;
+
+			var move = helicopter.FlyStep(helicopter.Facing);
+			helicopter.SetPosition(self, helicopter.CenterPosition + move);
+
+			var desiredFacing = helicopter.Facing + 64;
+			helicopter.Facing = Util.TickFacing(helicopter.Facing, desiredFacing, helicopter.ROT / 3);
+
+			return this;
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Air/HeliLand.cs

@@ -0,0 +1,41 @@
+#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 OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class HeliLand : Activity
+	{
+		bool requireSpace;
+
+		public HeliLand(bool requireSpace)
+		{
+			this.requireSpace = requireSpace;
+		}
+
+		public override Activity Tick(Actor self)
+		{
+			if (IsCanceled)
+				return NextActivity;
+
+			var helicopter = self.Trait<Helicopter>();
+
+			if (requireSpace && !helicopter.CanLand(self.Location))
+				return this;
+
+			if (HeliFly.AdjustAltitude(self, helicopter, helicopter.Info.LandAltitude))
+				return this;
+
+			return NextActivity;
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Air/HeliReturn.cs

@@ -0,0 +1,68 @@
+#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.Linq;
+using OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class HeliReturn : Activity
+	{
+		static Actor ChooseHelipad(Actor self)
+		{
+			var rearmBuildings = self.Info.Traits.Get<HelicopterInfo>().RearmBuildings;
+			return self.World.Actors.Where(a => a.Owner == self.Owner).FirstOrDefault(
+				a => rearmBuildings.Contains(a.Info.Name) && !Reservable.IsReserved(a));
+		}
+
+		public override Activity Tick(Actor self)
+		{
+			if (IsCanceled)
+				return NextActivity;
+
+			var dest = ChooseHelipad(self);
+			var initialFacing = self.Info.Traits.Get<AircraftInfo>().InitialFacing;
+
+			if (dest == null)
+			{
+				var rearmBuildings = self.Info.Traits.Get<HelicopterInfo>().RearmBuildings;
+				var nearestHpad = self.World.ActorsWithTrait<Reservable>()
+									.Where(a => a.Actor.Owner == self.Owner && rearmBuildings.Contains(a.Actor.Info.Name))
+									.Select(a => a.Actor)
+									.ClosestTo(self);
+
+				if (nearestHpad == null)
+					return Util.SequenceActivities(new Turn(self, initialFacing), new HeliLand(true), NextActivity);
+				else
+					return Util.SequenceActivities(new HeliFly(self, Target.FromActor(nearestHpad)));
+			}
+
+			var res = dest.TraitOrDefault<Reservable>();
+			var heli = self.Trait<Helicopter>();
+
+			if (res != null)
+			{
+				heli.UnReserve();
+				heli.Reservation = res.Reserve(dest, self, heli);
+			}
+
+			var exit = dest.Info.Traits.WithInterface<ExitInfo>().FirstOrDefault();
+			var offset = (exit != null) ? exit.SpawnOffset : WVec.Zero;
+
+			return Util.SequenceActivities(
+				new HeliFly(self, Target.FromPos(dest.CenterPosition + offset)),
+				new Turn(self, initialFacing),
+				new HeliLand(false),
+				new ResupplyAircraft());
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Air/Land.cs

@@ -0,0 +1,48 @@
+#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 OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class Land : Activity
+	{
+		Target target;
+
+		public Land(Target t) { target = t; }
+
+		public override Activity Tick(Actor self)
+		{
+			if (!target.IsValidFor(self))
+				Cancel(self);
+
+			if (IsCanceled)
+				return NextActivity;
+
+			var plane = self.Trait<Plane>();
+			var d = target.CenterPosition - self.CenterPosition;
+
+			// The next move would overshoot, so just set the final position
+			var move = plane.FlyStep(plane.Facing);
+			if (d.HorizontalLengthSquared < move.HorizontalLengthSquared)
+			{
+				plane.SetPosition(self, target.CenterPosition);
+				return NextActivity;
+			}
+
+			var desiredFacing = Util.GetFacing(d, plane.Facing);
+			Fly.FlyToward(self, plane, desiredFacing, WRange.Zero);
+
+			return this;
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Air/ResupplyAircraft.cs

@@ -0,0 +1,35 @@
+#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 System.Linq;
+using OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Primitives;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class ResupplyAircraft : Activity
+	{
+		public override Activity Tick(Actor self)
+		{
+			var aircraft = self.Trait<Aircraft>();
+			var host = aircraft.GetActorBelow();
+
+			if (host == null)
+				return NextActivity;
+
+			return Util.SequenceActivities(
+				aircraft.GetResupplyActivities(host).Append(NextActivity).ToArray());
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Air/ReturnToBase.cs

@@ -0,0 +1,127 @@
+#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.Linq;
+using OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class ReturnToBase : Activity
+	{
+		bool isCalculated;
+		Actor dest;
+		WPos w1, w2, w3;
+
+		public static Actor ChooseAirfield(Actor self, bool unreservedOnly)
+		{
+			var rearmBuildings = self.Info.Traits.Get<PlaneInfo>().RearmBuildings;
+			return self.World.ActorsWithTrait<Reservable>()
+				.Where(a => a.Actor.Owner == self.Owner)
+				.Where(a => rearmBuildings.Contains(a.Actor.Info.Name)
+					&& (!unreservedOnly || !Reservable.IsReserved(a.Actor)))
+				.Select(a => a.Actor)
+				.ClosestTo(self);
+		}
+
+		void Calculate(Actor self)
+		{
+			if (dest == null || Reservable.IsReserved(dest))
+				dest = ChooseAirfield(self, true);
+
+			if (dest == null)
+				return;
+
+			var plane = self.Trait<Plane>();
+			var planeInfo = self.Info.Traits.Get<PlaneInfo>();
+			var res = dest.TraitOrDefault<Reservable>();
+			if (res != null)
+			{
+				plane.UnReserve();
+				plane.Reservation = res.Reserve(dest, self, plane);
+			}
+
+			var landPos = dest.CenterPosition;
+			var altitude = planeInfo.CruiseAltitude.Range;
+
+			// Distance required for descent.
+			var landDistance = altitude * 1024 / plane.Info.MaximumPitch.Tan();
+
+			// Land towards the east
+			var approachStart = landPos + new WVec(-landDistance, 0, altitude);
+
+			// Add 10% to the turning radius to ensure we have enough room
+			var speed = plane.MovementSpeed * 32 / 35;
+			var turnRadius = (int)(141 * speed / planeInfo.ROT / (float)Math.PI);
+
+			// Find the center of the turning circles for clockwise and counterclockwise turns
+			var angle = WAngle.FromFacing(plane.Facing);
+			var fwd = -new WVec(angle.Sin(), angle.Cos(), 0);
+
+			// Work out whether we should turn clockwise or counter-clockwise for approach
+			var side = new WVec(-fwd.Y, fwd.X, fwd.Z);
+			var approachDelta = self.CenterPosition - approachStart;
+			var sideTowardBase = new[] { side, -side }
+				.MinBy(a => WVec.Dot(a, approachDelta));
+
+			// Calculate the tangent line that joins the turning circles at the current and approach positions
+			var cp = self.CenterPosition + turnRadius * sideTowardBase / 1024;
+			var posCenter = new WPos(cp.X, cp.Y, altitude);
+			var approachCenter = approachStart + new WVec(0, turnRadius * Math.Sign(self.CenterPosition.Y - approachStart.Y), 0);
+			var tangentDirection = approachCenter - posCenter;
+			var tangentOffset = new WVec(-tangentDirection.Y, tangentDirection.X, 0) * turnRadius / tangentDirection.Length;
+
+			// TODO: correctly handle CCW <-> CW turns
+			if (tangentOffset.X > 0)
+				tangentOffset = -tangentOffset;
+
+			w1 = posCenter + tangentOffset;
+			w2 = approachCenter + tangentOffset;
+			w3 = approachStart;
+			plane.RTBPathHash = w1 + (WVec)w2 + (WVec)w3;
+
+			isCalculated = true;
+		}
+
+		public ReturnToBase(Actor self, Actor dest)
+		{
+			this.dest = dest;
+		}
+
+		public override Activity Tick(Actor self)
+		{
+			if (IsCanceled || self.IsDead)
+				return NextActivity;
+
+			if (!isCalculated)
+				Calculate(self);
+
+			if (dest == null)
+			{
+				var nearestAfld = ChooseAirfield(self, false);
+				
+				self.CancelActivity();
+				if (nearestAfld != null)
+					return Util.SequenceActivities(new Fly(self, Target.FromActor(nearestAfld)), new FlyCircle());
+				else
+					return new FlyCircle();
+			}
+
+			return Util.SequenceActivities(
+				new Fly(self, Target.FromPos(w1)),
+				new Fly(self, Target.FromPos(w2)),
+				new Fly(self, Target.FromPos(w3)),
+				new Land(Target.FromActor(dest)),
+				NextActivity);
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Air/TakeOff.cs

@@ -0,0 +1,42 @@
+#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 OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class TakeOff : Activity
+	{
+		public override Activity Tick(Actor self)
+		{
+			var aircraft = self.Trait<Aircraft>();
+
+			self.CancelActivity();
+
+			var reservation = aircraft.Reservation;
+			if (reservation != null)
+			{
+				reservation.Dispose();
+				reservation = null;
+			}
+
+			var host = aircraft.GetActorBelow();
+			var hasHost = host != null;
+			var rp = hasHost ? host.TraitOrDefault<RallyPoint>() : null;
+
+			var destination = rp != null ? rp.Location :
+				(hasHost ? self.World.Map.CellContaining(host.CenterPosition) : self.Location);
+
+			return new AttackMoveActivity(self, self.Trait<IMove>().MoveTo(destination, 1));
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Attack.cs

@@ -0,0 +1,80 @@
+#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 OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	/* non-turreted attack */
+	public class Attack : Activity
+	{
+		protected readonly Target Target;
+		readonly AttackBase attack;
+		readonly IMove move;
+		readonly IFacing facing;
+		readonly WRange minRange;
+		readonly WRange maxRange;
+		readonly IPositionable positionable;
+
+		public Attack(Actor self, Target target, WRange minRange, WRange maxRange, bool allowMovement)
+		{
+			Target = target;
+			this.minRange = minRange;
+			this.maxRange = maxRange;
+
+			attack = self.Trait<AttackBase>();
+			facing = self.Trait<IFacing>();
+			positionable = self.Trait<IPositionable>();
+
+			move = allowMovement ? self.TraitOrDefault<IMove>() : null;
+		}
+
+		public override Activity Tick(Actor self)
+		{
+			var ret = InnerTick(self, attack);
+			attack.IsAttacking = ret == this;
+			return ret;
+		}
+
+		protected virtual Activity InnerTick(Actor self, AttackBase attack)
+		{
+			if (IsCanceled)
+				return NextActivity;
+
+			var type = Target.Type;
+			if (!Target.IsValidFor(self) || type == TargetType.FrozenActor)
+				return NextActivity;
+			
+			if (attack.Info.AttackRequiresEnteringCell && !positionable.CanEnterCell(Target.Actor.Location, null, false))
+				return NextActivity;
+
+			// Drop the target if it moves under the shroud / fog.
+			// HACK: This would otherwise break targeting frozen actors
+			// The problem is that Shroud.IsTargetable returns false (as it should) for
+			// frozen actors, but we do want to explicitly target the underlying actor here.
+			if (type == TargetType.Actor && !Target.Actor.HasTrait<FrozenUnderFog>() && !self.Owner.Shroud.IsTargetable(Target.Actor))
+				return NextActivity;
+
+			// Try to move within range
+			if (move != null && (!Target.IsInRange(self.CenterPosition, maxRange) || Target.IsInRange(self.CenterPosition, minRange)))
+				return Util.SequenceActivities(move.MoveWithinRange(Target, minRange, maxRange), this);
+
+			var desiredFacing = Util.GetFacing(Target.CenterPosition - self.CenterPosition, 0);
+			if (facing.Facing != desiredFacing)
+				return Util.SequenceActivities(new Turn(self, desiredFacing), this);
+
+			attack.DoAttack(self, Target);
+
+			return this;
+		}
+	}
+}

OpenRA.Mods.Common/Activities/EnterTransport.cs

@@ -0,0 +1,71 @@
+#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 OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	class EnterTransport : Enter
+	{
+		readonly Actor transport;
+		readonly Passenger passenger;
+		readonly int maxTries;
+		Cargo cargo;
+
+		public EnterTransport(Actor self, Actor transport, int maxTries = 0, bool targetCenter = false)
+			: base(self, transport, maxTries, targetCenter)
+		{
+			this.transport = transport;
+			this.maxTries = maxTries;
+			cargo = transport.Trait<Cargo>();
+			passenger = self.Trait<Passenger>();
+		}
+
+		protected override void Unreserve(Actor self, bool abort) { passenger.Unreserve(self); }
+		protected override bool CanReserve(Actor self) { return cargo.Unloading || cargo.CanLoad(transport, self); }
+		protected override ReserveStatus Reserve(Actor self)
+		{
+			var status = base.Reserve(self);
+			if (status != ReserveStatus.Ready)
+				return status;
+			if (passenger.Reserve(self, cargo))
+				return ReserveStatus.Ready;
+			return ReserveStatus.Pending;
+		}
+
+		protected override void OnInside(Actor self)
+		{
+			self.World.AddFrameEndTask(w => 
+			{
+				if (self.IsDead || transport.IsDead || !cargo.CanLoad(transport, self))
+					return;
+
+				cargo.Load(transport, self);
+				w.Remove(self);
+			});
+
+			Done(self);
+		}
+
+		protected override bool TryGetAlternateTarget(Actor self, int tries, ref Target target)
+		{
+			if (tries > maxTries)
+				return false;
+			var type = target.Actor.Info.Name;
+			return TryGetAlternateTargetInCircle(
+				self, passenger.Info.AlternateTransportScanRange,
+				t => cargo = t.Actor.Trait<Cargo>(), // update cargo
+				a => { var c = a.TraitOrDefault<Cargo>(); return c != null && (c.Unloading || c.CanLoad(a, self)); },
+				new Func<Actor, bool>[] { a => a.Info.Name == type }); // Prefer transports of the same type
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Heal.cs

@@ -0,0 +1,33 @@
+#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 OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class Heal : Attack
+	{
+		public Heal(Actor self, Target target, WRange minRange, WRange maxRange, bool allowMovement)
+			: base(self, target, minRange, maxRange, allowMovement) { }
+
+		protected override Activity InnerTick(Actor self, AttackBase attack)
+		{
+			if (!Target.IsValidFor(self) || !self.Owner.IsAlliedWith(Target.Actor.Owner))
+				return NextActivity;
+
+			if (Target.Type == TargetType.Actor && Target.Actor.GetDamageState() == DamageState.Undamaged)
+				return NextActivity;
+
+			return base.InnerTick(self, attack);
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Move/AttackMoveActivity.cs

@@ -0,0 +1,64 @@
+#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.Collections.Generic;
+using OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class AttackMoveActivity : Activity
+	{
+		const int ScanInterval = 7;
+
+		Activity inner;
+		int scanTicks;
+		AutoTarget autoTarget;
+
+		public AttackMoveActivity(Actor self, Activity inner)
+		{
+			this.inner = inner;
+			autoTarget = self.TraitOrDefault<AutoTarget>();
+		}
+
+		public override Activity Tick(Actor self)
+		{
+			if (autoTarget != null && --scanTicks <= 0)
+			{
+				autoTarget.ScanAndAttack(self);
+				scanTicks = ScanInterval;
+			}
+
+			if (inner == null)
+				return NextActivity;
+
+			inner = Util.RunActivity(self, inner);
+
+			return this;
+		}
+
+		public override void Cancel(Actor self)
+		{
+			if (inner != null)
+				inner.Cancel(self);
+
+			base.Cancel(self);
+		}
+
+		public override IEnumerable<Target> GetTargets(Actor self)
+		{
+			if (inner != null)
+				return inner.GetTargets(self);
+
+			return Target.None;
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Move/Follow.cs

@@ -0,0 +1,50 @@
+#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 OpenRA.Activities;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class Follow : Activity
+	{
+		readonly Target target;
+		readonly WRange minRange;
+		readonly WRange maxRange;
+		readonly IMove move;
+
+		public Follow(Actor self, Target target, WRange minRange, WRange maxRange)
+		{
+			this.target = target;
+			this.minRange = minRange;
+			this.maxRange = maxRange;
+
+			move = self.Trait<IMove>();
+		}
+
+		public override Activity Tick(Actor self)
+		{
+			if (IsCanceled || !target.IsValidFor(self))
+				return NextActivity;
+
+			var cachedPosition = target.CenterPosition;
+			var path = move.MoveWithinRange(target, minRange, maxRange);
+
+			// We are already in range, so wait until the target moves before doing anything
+			if (target.IsInRange(self.CenterPosition, maxRange) && !target.IsInRange(self.CenterPosition, minRange))
+			{
+				var wait = new WaitFor(() => !target.IsValidFor(self) || target.CenterPosition != cachedPosition);
+				return Util.SequenceActivities(wait, path, this);
+			}
+
+			return Util.SequenceActivities(path, this);
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Move/Move.cs

@@ -0,0 +1,451 @@
+#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 System.Diagnostics;
+using System.Linq;
+using OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Primitives;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class Move : Activity
+	{
+		static readonly List<CPos> NoPath = new List<CPos>();
+
+		readonly Mobile mobile;
+		readonly IEnumerable<IDisableMove> moveDisablers;
+		readonly WRange nearEnough;
+		readonly Func<List<CPos>> getPath;
+		readonly Actor ignoredActor;
+
+		List<CPos> path;
+		CPos? destination;
+
+		// For dealing with blockers
+		bool hasWaited;
+		bool hasNotifiedBlocker;
+		int waitTicksRemaining;
+
+		// Scriptable move order
+		// Ignores lane bias and nearby units
+		public Move(Actor self, CPos destination)
+		{
+			mobile = self.Trait<Mobile>();
+			moveDisablers = self.TraitsImplementing<IDisableMove>();
+
+			getPath = () =>
+				self.World.WorldActor.Trait<PathFinder>().FindPath(
+					PathSearch.FromPoint(self.World, mobile.Info, self, mobile.toCell, destination, false)
+					.WithoutLaneBias());
+			this.destination = destination;
+			this.nearEnough = WRange.Zero;
+		}
+
+		// HACK: for legacy code
+		public Move(Actor self, CPos destination, int nearEnough)
+			: this(self, destination, WRange.FromCells(nearEnough)) { }
+
+		public Move(Actor self, CPos destination, WRange nearEnough)
+		{
+			mobile = self.Trait<Mobile>();
+			moveDisablers = self.TraitsImplementing<IDisableMove>();
+
+			getPath = () => self.World.WorldActor.Trait<PathFinder>()
+				.FindUnitPath(mobile.toCell, destination, self);
+			this.destination = destination;
+			this.nearEnough = nearEnough;
+		}
+
+		public Move(Actor self, CPos destination, SubCell subCell, WRange nearEnough)
+		{
+			mobile = self.Trait<Mobile>();
+			moveDisablers = self.TraitsImplementing<IDisableMove>();
+
+			getPath = () => self.World.WorldActor.Trait<PathFinder>()
+				.FindUnitPathToRange(mobile.fromCell, subCell, self.World.Map.CenterOfSubCell(destination, subCell), nearEnough, self);
+			this.destination = destination;
+			this.nearEnough = nearEnough;
+		}
+
+		public Move(Actor self, CPos destination, Actor ignoredActor)
+		{
+			mobile = self.Trait<Mobile>();
+			moveDisablers = self.TraitsImplementing<IDisableMove>();
+
+			getPath = () =>
+				self.World.WorldActor.Trait<PathFinder>().FindPath(
+					PathSearch.FromPoint(self.World, mobile.Info, self, mobile.toCell, destination, false)
+					.WithIgnoredActor(ignoredActor));
+
+			this.destination = destination;
+			this.nearEnough = WRange.Zero;
+			this.ignoredActor = ignoredActor;
+		}
+
+		public Move(Actor self, Target target, WRange range)
+		{
+			mobile = self.Trait<Mobile>();
+			moveDisablers = self.TraitsImplementing<IDisableMove>();
+
+			getPath = () =>
+			{
+				if (!target.IsValidFor(self))
+					return NoPath;
+
+				return self.World.WorldActor.Trait<PathFinder>().FindUnitPathToRange(
+					mobile.toCell, mobile.toSubCell, target.CenterPosition, range, self);
+			};
+
+			destination = null;
+			nearEnough = range;
+		}
+
+		public Move(Actor self, Func<List<CPos>> getPath)
+		{
+			mobile = self.Trait<Mobile>();
+			moveDisablers = self.TraitsImplementing<IDisableMove>();
+
+			this.getPath = getPath;
+
+			destination = null;
+			nearEnough = WRange.Zero;
+		}
+
+		static int HashList<T>(List<T> xs)
+		{
+			var hash = 0;
+			var n = 0;
+			foreach (var x in xs)
+				hash += n++ * x.GetHashCode();
+
+			return hash;
+		}
+
+		List<CPos> EvalPath(Actor self, Mobile mobile)
+		{
+			var path = getPath().TakeWhile(a => a != mobile.toCell).ToList();
+			mobile.PathHash = HashList(path);
+			return path;
+		}
+
+		public override Activity Tick(Actor self)
+		{
+			if (moveDisablers.Any(d => d.MoveDisabled(self)))
+				return this;
+
+			if (destination == mobile.toCell)
+				return NextActivity;
+
+			if (path == null)
+			{
+				if (mobile.ticksBeforePathing > 0)
+				{
+					--mobile.ticksBeforePathing;
+					return this;
+				}
+
+				path = EvalPath(self, mobile);
+				SanityCheckPath(mobile);
+			}
+
+			if (path.Count == 0)
+			{
+				destination = mobile.toCell;
+				return this;
+			}
+
+			destination = path[0];
+
+			var nextCell = PopPath(self, mobile);
+			if (nextCell == null)
+				return this;
+
+			var firstFacing = self.World.Map.FacingBetween(mobile.fromCell, nextCell.Value.First, mobile.Facing);
+			if (firstFacing != mobile.Facing)
+			{
+				path.Add(nextCell.Value.First);
+				return Util.SequenceActivities(new Turn(self, firstFacing), this);
+			}
+			else
+			{
+				mobile.SetLocation(mobile.fromCell, mobile.fromSubCell, nextCell.Value.First, nextCell.Value.Second);
+				var move = new MoveFirstHalf(
+					this,
+					self.World.Map.CenterOfSubCell(mobile.fromCell, mobile.fromSubCell),
+					Util.BetweenCells(self.World, mobile.fromCell, mobile.toCell) + (self.World.Map.OffsetOfSubCell(mobile.fromSubCell) + self.World.Map.OffsetOfSubCell(mobile.toSubCell)) / 2,
+					mobile.Facing,
+					mobile.Facing,
+					0);
+
+				return move;
+			}
+		}
+
+		[Conditional("SANITY_CHECKS")]
+		void SanityCheckPath(Mobile mobile)
+		{
+			if (path.Count == 0)
+				return;
+			var d = path[path.Count - 1] - mobile.toCell;
+			if (d.LengthSquared > 2)
+				throw new InvalidOperationException("(Move) Sanity check failed");
+		}
+
+		static void NotifyBlocker(Actor self, CPos nextCell)
+		{
+			foreach (var blocker in self.World.ActorMap.GetUnitsAt(nextCell))
+			{
+				// Notify the blocker that he's blocking our move:
+				foreach (var moveBlocked in blocker.TraitsImplementing<INotifyBlockingMove>())
+					moveBlocked.OnNotifyBlockingMove(blocker, self);
+			}
+		}
+
+		Pair<CPos, SubCell>? PopPath(Actor self, Mobile mobile)
+		{
+			if (path.Count == 0)
+				return null;
+
+			var nextCell = path[path.Count - 1];
+
+			// Next cell in the move is blocked by another actor
+			if (!mobile.CanEnterCell(nextCell, ignoredActor, true))
+			{
+				// Are we close enough?
+				var cellRange = nearEnough.Range / 1024;
+				if ((mobile.toCell - destination.Value).LengthSquared <= cellRange * cellRange)
+				{
+					path.Clear();
+					return null;
+				}
+
+				// See if they will move
+				if (!hasNotifiedBlocker)
+				{
+					NotifyBlocker(self, nextCell);
+					hasNotifiedBlocker = true;
+				}
+
+				// Wait a bit to see if they leave
+				if (!hasWaited)
+				{
+					var info = self.Info.Traits.Get<MobileInfo>();
+					waitTicksRemaining = info.WaitAverage + self.World.SharedRandom.Next(-info.WaitSpread, info.WaitSpread);
+					hasWaited = true;
+				}
+
+				if (--waitTicksRemaining >= 0)
+					return null;
+
+				if (mobile.ticksBeforePathing > 0)
+				{
+					--mobile.ticksBeforePathing;
+					return null;
+				}
+
+				// Calculate a new path
+				mobile.RemoveInfluence();
+				var newPath = EvalPath(self, mobile);
+				mobile.AddInfluence();
+
+				if (newPath.Count != 0)
+					path = newPath;
+
+				return null;
+			}
+
+			hasNotifiedBlocker = false;
+			hasWaited = false;
+			path.RemoveAt(path.Count - 1);
+
+			var subCell = mobile.GetAvailableSubCell(nextCell, SubCell.Any, ignoredActor);
+			return Pair.New(nextCell, subCell);
+		}
+
+		public override void Cancel(Actor self)
+		{
+			path = NoPath;
+			base.Cancel(self);
+		}
+
+		public override IEnumerable<Target> GetTargets(Actor self)
+		{
+			if (path != null)
+				return Enumerable.Reverse(path).Select(c => Target.FromCell(self.World, c));
+			if (destination != null)
+				return new Target[] { Target.FromCell(self.World, destination.Value) };
+			return Target.None;
+		}
+
+		abstract class MovePart : Activity
+		{
+			protected readonly Move move;
+			protected readonly WPos from, to;
+			protected readonly int fromFacing, toFacing;
+			protected readonly int moveFractionTotal;
+			protected int moveFraction;
+
+			public MovePart(Move move, WPos from, WPos to, int fromFacing, int toFacing, int startingFraction)
+			{
+				this.move = move;
+				this.from = from;
+				this.to = to;
+				this.fromFacing = fromFacing;
+				this.toFacing = toFacing;
+				this.moveFraction = startingFraction;
+				this.moveFractionTotal = (to - from).Length;
+			}
+
+			public override void Cancel(Actor self)
+			{
+				move.Cancel(self);
+				base.Cancel(self);
+			}
+
+			public override void Queue(Activity activity)
+			{
+				move.Queue(activity);
+			}
+
+			public override Activity Tick(Actor self)
+			{
+				var mobile = self.Trait<Mobile>();
+				var ret = InnerTick(self, move.mobile);
+				mobile.IsMoving = ret is MovePart;
+
+				if (moveFraction > moveFractionTotal)
+					moveFraction = moveFractionTotal;
+				UpdateCenterLocation(self, mobile);
+
+				return ret;
+			}
+
+			Activity InnerTick(Actor self, Mobile mobile)
+			{
+				moveFraction += mobile.MovementSpeedForCell(self, mobile.toCell);
+				if (moveFraction <= moveFractionTotal)
+					return this;
+
+				var next = OnComplete(self, mobile, move);
+				if (next != null)
+					return next;
+
+				return move;
+			}
+
+			void UpdateCenterLocation(Actor self, Mobile mobile)
+			{
+				// avoid division through zero
+				if (moveFractionTotal != 0)
+					mobile.SetVisualPosition(self, WPos.Lerp(from, to, moveFraction, moveFractionTotal));
+				else
+					mobile.SetVisualPosition(self, to);
+
+				if (moveFraction >= moveFractionTotal)
+					mobile.Facing = toFacing & 0xFF;
+				else
+					mobile.Facing = int2.Lerp(fromFacing, toFacing, moveFraction, moveFractionTotal) & 0xFF;
+			}
+
+			protected abstract MovePart OnComplete(Actor self, Mobile mobile, Move parent);
+
+			public override IEnumerable<Target> GetTargets(Actor self)
+			{
+				return move.GetTargets(self);
+			}
+		}
+
+		class MoveFirstHalf : MovePart
+		{
+			public MoveFirstHalf(Move move, WPos from, WPos to, int fromFacing, int toFacing, int startingFraction)
+				: base(move, from, to, fromFacing, toFacing, startingFraction) { }
+
+			static bool IsTurn(Mobile mobile, CPos nextCell)
+			{
+				return nextCell - mobile.toCell !=
+					mobile.toCell - mobile.fromCell;
+			}
+
+			protected override MovePart OnComplete(Actor self, Mobile mobile, Move parent)
+			{
+				var fromSubcellOffset = self.World.Map.OffsetOfSubCell(mobile.fromSubCell);
+				var toSubcellOffset = self.World.Map.OffsetOfSubCell(mobile.toSubCell);
+
+				var nextCell = parent.PopPath(self, mobile);
+				if (nextCell != null)
+				{
+					if (IsTurn(mobile, nextCell.Value.First))
+					{
+						var nextSubcellOffset = self.World.Map.OffsetOfSubCell(nextCell.Value.Second);
+						var ret = new MoveFirstHalf(
+							move,
+							Util.BetweenCells(self.World, mobile.fromCell, mobile.toCell) + (fromSubcellOffset + toSubcellOffset) / 2,
+							Util.BetweenCells(self.World, mobile.toCell, nextCell.Value.First) + (toSubcellOffset + nextSubcellOffset) / 2,
+							mobile.Facing,
+							Util.GetNearestFacing(mobile.Facing, self.World.Map.FacingBetween(mobile.toCell, nextCell.Value.First, mobile.Facing)),
+							moveFraction - moveFractionTotal);
+
+						mobile.FinishedMoving(self);
+						mobile.SetLocation(mobile.toCell, mobile.toSubCell, nextCell.Value.First, nextCell.Value.Second);
+						return ret;
+					}
+
+					parent.path.Add(nextCell.Value.First);
+				}
+
+				var ret2 = new MoveSecondHalf(
+					move,
+					Util.BetweenCells(self.World, mobile.fromCell, mobile.toCell) + (fromSubcellOffset + toSubcellOffset) / 2,
+					self.World.Map.CenterOfCell(mobile.toCell) + toSubcellOffset,
+					mobile.Facing,
+					mobile.Facing,
+					moveFraction - moveFractionTotal);
+
+				mobile.EnteringCell(self);
+				mobile.SetLocation(mobile.toCell, mobile.toSubCell, mobile.toCell, mobile.toSubCell);
+				return ret2;
+			}
+		}
+
+		class MoveSecondHalf : MovePart
+		{
+			public MoveSecondHalf(Move move, WPos from, WPos to, int fromFacing, int toFacing, int startingFraction)
+				: base(move, from, to, fromFacing, toFacing, startingFraction) { }
+
+			protected override MovePart OnComplete(Actor self, Mobile mobile, Move parent)
+			{
+				mobile.SetPosition(self, mobile.toCell);
+				return null;
+			}
+		}
+	}
+
+	public static class ActorExtensionsForMove
+	{
+		public static bool IsMoving(this Actor self)
+		{
+			var a = self.GetCurrentActivity();
+			if (a == null)
+				return false;
+
+			// HACK: Dirty, but it suffices until we do something better:
+			if (a.GetType() == typeof(Move)) return true;
+			if (a.GetType() == typeof(MoveAdjacentTo)) return true;
+			if (a.GetType() == typeof(AttackMoveActivity)) return true;
+
+			// Not a move:
+			return false;
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Move/MoveAdjacentTo.cs

@@ -0,0 +1,144 @@
+#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 System.Linq;
+using OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class MoveAdjacentTo : Activity
+	{
+		static readonly List<CPos> NoPath = new List<CPos>();
+
+		readonly Mobile mobile;
+		readonly PathFinder pathFinder;
+		readonly DomainIndex domainIndex;
+		readonly uint movementClass;
+
+		protected Target target { get; private set; }
+		protected CPos targetPosition;
+		Activity inner;
+		bool repath;
+
+		public MoveAdjacentTo(Actor self, Target target)
+		{
+			this.target = target;
+
+			mobile = self.Trait<Mobile>();
+			pathFinder = self.World.WorldActor.Trait<PathFinder>();
+			domainIndex = self.World.WorldActor.Trait<DomainIndex>();
+			movementClass = (uint)mobile.Info.GetMovementClass(self.World.TileSet);
+
+			if (target.IsValidFor(self))
+				targetPosition = self.World.Map.CellContaining(target.CenterPosition);
+
+			repath = true;
+		}
+
+		protected virtual bool ShouldStop(Actor self, CPos oldTargetPosition)
+		{
+			return false;
+		}
+
+		protected virtual bool ShouldRepath(Actor self, CPos oldTargetPosition)
+		{
+			return targetPosition != oldTargetPosition;
+		}
+
+		protected virtual IEnumerable<CPos> CandidateMovementCells(Actor self)
+		{
+			return Util.AdjacentCells(self.World, target);
+		}
+
+		public override Activity Tick(Actor self)
+		{
+			var targetIsValid = target.IsValidFor(self);
+
+			// Inner move order has completed.
+			if (inner == null)
+			{
+				// We are done here if the order was cancelled for any
+				// reason except the target moving.
+				if (IsCanceled || !repath || !targetIsValid)
+					return NextActivity;
+
+				// Target has moved, and MoveAdjacentTo is still valid.
+				inner = mobile.MoveTo(() => CalculatePathToTarget(self));
+				repath = false;
+			}
+
+			if (targetIsValid)
+			{
+				// Check if the target has moved
+				var oldTargetPosition = targetPosition;
+				targetPosition = self.World.Map.CellContaining(target.CenterPosition);
+
+				var shouldStop = ShouldStop(self, oldTargetPosition);
+				if (shouldStop || (!repath && ShouldRepath(self, oldTargetPosition)))
+				{
+					// Finish moving into the next cell and then repath.
+					if (inner != null)
+						inner.Cancel(self);
+
+					repath = !shouldStop;
+				}
+			}
+			else
+			{
+				// Target became invalid. Move to its last known position.
+				target = Target.FromCell(self.World, targetPosition);
+			}
+
+			// Ticks the inner move activity to actually move the actor.
+			inner = Util.RunActivity(self, inner);
+
+			return this;
+		}
+
+		List<CPos> CalculatePathToTarget(Actor self)
+		{
+			var targetCells = CandidateMovementCells(self);
+			var searchCells = new List<CPos>();
+			var loc = self.Location;
+
+			foreach (var cell in targetCells)
+				if (domainIndex.IsPassable(loc, cell, movementClass) && mobile.CanEnterCell(cell))
+					searchCells.Add(cell);
+
+			if (!searchCells.Any())
+				return NoPath;
+
+			var fromSrc = PathSearch.FromPoints(self.World, mobile.Info, self, searchCells, loc, true);
+			var fromDest = PathSearch.FromPoint(self.World, mobile.Info, self, loc, targetPosition, true).Reverse();
+
+			return pathFinder.FindBidiPath(fromSrc, fromDest);
+		}
+
+		public override IEnumerable<Target> GetTargets(Actor self)
+		{
+			if (inner != null)
+				return inner.GetTargets(self);
+
+			return Target.None;
+		}
+
+		public override void Cancel(Actor self)
+		{
+			if (inner != null)
+				inner.Cancel(self);
+
+			base.Cancel(self);
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Move/MoveWithinRange.cs

@@ -0,0 +1,62 @@
+#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.Collections.Generic;
+using System.Linq;
+using OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class MoveWithinRange : MoveAdjacentTo
+	{
+		readonly WRange maxRange;
+		readonly WRange minRange;
+
+		public MoveWithinRange(Actor self, Target target, WRange minRange, WRange maxRange)
+			: base(self, target)
+		{
+			this.minRange = minRange;
+			this.maxRange = maxRange;
+		}
+
+		protected override bool ShouldStop(Actor self, CPos oldTargetPosition)
+		{
+			// We are now in range. Don't move any further!
+			// HACK: This works around the pathfinder not returning the shortest path
+			var cp = self.CenterPosition;
+			return target.IsInRange(cp, maxRange) && !target.IsInRange(cp, minRange);
+		}
+
+		protected override bool ShouldRepath(Actor self, CPos oldTargetPosition)
+		{
+			var cp = self.CenterPosition;
+			return targetPosition != oldTargetPosition && (!target.IsInRange(cp, maxRange) || target.IsInRange(cp, minRange));
+		}
+
+		protected override IEnumerable<CPos> CandidateMovementCells(Actor self)
+		{
+			var map = self.World.Map;
+			var maxCells = (maxRange.Range + 1023) / 1024;
+			var minCells = minRange.Range / 1024;
+
+			var outerSq = maxRange.Range * maxRange.Range;
+			var innerSq = minRange.Range * minRange.Range;
+			var center = target.CenterPosition;
+
+			return map.FindTilesInAnnulus(targetPosition, minCells + 1, maxCells).Where(c =>
+			{
+				var dxSq = (map.CenterOfCell(c) - center).HorizontalLengthSquared;
+				return dxSq >= innerSq && dxSq <= outerSq;
+			});
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Rearm.cs

@@ -0,0 +1,60 @@
+#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.Linq;
+using OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class Rearm : Activity
+	{
+		readonly LimitedAmmo limitedAmmo;
+		int ticksPerPip = 25 * 2;
+		int remainingTicks = 25 * 2;
+		string sound = null;
+
+		public Rearm(Actor self, string sound = null)
+		{
+			limitedAmmo = self.TraitOrDefault<LimitedAmmo>();
+			if (limitedAmmo != null)
+				ticksPerPip = limitedAmmo.ReloadTimePerAmmo();
+			remainingTicks = ticksPerPip;
+			this.sound = sound;
+		}
+
+		public override Activity Tick(Actor self)
+		{
+			if (IsCanceled || limitedAmmo == null)
+				return NextActivity;
+
+			if (--remainingTicks == 0)
+			{
+				var hostBuilding = self.World.ActorMap.GetUnitsAt(self.Location)
+					.FirstOrDefault(a => a.HasTrait<RenderBuilding>());
+
+				if (hostBuilding == null || !hostBuilding.IsInWorld)
+					return NextActivity;
+
+				if (!limitedAmmo.GiveAmmo())
+					return NextActivity;
+
+				hostBuilding.Trait<RenderBuilding>().PlayCustomAnim(hostBuilding, "active");
+				if (sound != null)
+					Sound.Play(sound, self.CenterPosition);
+
+				remainingTicks = limitedAmmo.ReloadTimePerAmmo();
+			}
+
+			return this;
+		}
+	}
+}

OpenRA.Mods.Common/Activities/Repair.cs

@@ -0,0 +1,63 @@
+#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 OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class Repair : Activity
+	{
+		int remainingTicks;
+		Actor host;
+		Health health;
+
+		public Repair(Actor host) { this.host = host; }
+
+		public override Activity Tick(Actor self)
+		{
+			if (IsCanceled) return NextActivity;
+			if (host == null || !host.IsInWorld) return NextActivity;
+
+			health = self.TraitOrDefault<Health>();
+			if (health == null) return NextActivity;
+
+			if (health.DamageState == DamageState.Undamaged)
+				return NextActivity;
+
+			if (remainingTicks == 0)
+			{
+				var repairsUnits = host.Info.Traits.Get<RepairsUnitsInfo>();
+				var unitCost = self.Info.Traits.Get<ValuedInfo>().Cost;
+				var hpToRepair = repairsUnits.HpPerStep;
+				var cost = Math.Max(1, (hpToRepair * unitCost * repairsUnits.ValuePercentage) / (health.MaxHP * 100));
+
+				if (!self.Owner.PlayerActor.Trait<PlayerResources>().TakeCash(cost))
+				{
+					remainingTicks = 1;
+					return this;
+				}
+
+				self.InflictDamage(self, -hpToRepair, null);
+
+				foreach (var depot in host.TraitsImplementing<INotifyRepair>())
+					depot.Repairing(self, host);
+
+				remainingTicks = repairsUnits.Interval;
+			}
+			else
+				--remainingTicks;
+
+			return this;
+		}
+	}
+}

OpenRA.Mods.Common/Activities/UnloadCargo.cs

@@ -0,0 +1,103 @@
+#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.Collections.Generic;
+using System.Drawing;
+using System.Linq;
+using OpenRA.Activities;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Primitives;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Activities
+{
+	public class UnloadCargo : Activity
+	{
+		readonly Actor self;
+		readonly Cargo cargo;
+		readonly Cloak cloak;
+		readonly bool unloadAll;
+
+		public UnloadCargo(Actor self, bool unloadAll)
+		{
+			this.self = self;
+			cargo = self.Trait<Cargo>();
+			cloak = self.TraitOrDefault<Cloak>();
+			this.unloadAll = unloadAll;
+		}
+
+		public Pair<CPos, SubCell>? ChooseExitSubCell(Actor passenger)
+		{
+			var pos = passenger.Trait<IPositionable>();
+
+			return cargo.CurrentAdjacentCells
+				.Shuffle(self.World.SharedRandom)
+				.Select(c => Pair.New(c, pos.GetAvailableSubCell(c)))
+				.Cast<Pair<CPos, SubCell>?>()
+				.FirstOrDefault(s => s.Value.Second != SubCell.Invalid);
+		}
+
+		IEnumerable<CPos> BlockedExitCells(Actor passenger)
+		{
+			var pos = passenger.Trait<IPositionable>();
+
+			// Find the cells that are blocked by transient actors
+			return cargo.CurrentAdjacentCells
+				.Where(c => pos.CanEnterCell(c, null, true) != pos.CanEnterCell(c, null, false));
+		}
+
+		public override Activity Tick(Actor self)
+		{
+			cargo.Unloading = false;
+			if (IsCanceled || cargo.IsEmpty(self))
+				return NextActivity;
+
+			if (cloak != null && cloak.Info.UncloakOnUnload)
+				cloak.Uncloak();
+
+			var actor = cargo.Peek(self);
+			var spawn = self.CenterPosition;
+
+			var exitSubCell = ChooseExitSubCell(actor);
+			if (exitSubCell == null)
+			{
+				foreach (var blocker in BlockedExitCells(actor).SelectMany(p => self.World.ActorMap.GetUnitsAt(p)))
+				{
+					foreach (var nbm in blocker.TraitsImplementing<INotifyBlockingMove>())
+						nbm.OnNotifyBlockingMove(blocker, self);
+				}
+
+				return Util.SequenceActivities(new Wait(10), this);
+			}
+
+			cargo.Unload(self);
+			self.World.AddFrameEndTask(w =>
+			{
+				if (actor.Destroyed)
+					return;
+
+				var move = actor.Trait<IMove>();
+				var pos = actor.Trait<IPositionable>();
+
+				actor.CancelActivity();
+				pos.SetVisualPosition(actor, spawn);
+				actor.QueueActivity(move.MoveIntoWorld(actor, exitSubCell.Value.First, exitSubCell.Value.Second));
+				actor.SetTargetLine(Target.FromCell(w, exitSubCell.Value.First, exitSubCell.Value.Second), Color.Green, false);
+				w.Add(actor);
+			});
+
+			if (!unloadAll || cargo.IsEmpty(self))
+				return NextActivity;
+
+			cargo.Unloading = true;
+			return this;
+		}
+	}
+}