Let docking angle be determined by the host building.

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

@@ -111,9 +111,12 @@ namespace OpenRA.Mods.Common.Activities
 			if (ShouldLandAtBuilding(self, dest))
 			{
 				var exit = dest.FirstExitOrDefault();
-				var offset = exit != null ? exit.Info.SpawnOffset : WVec.Zero;
-				if (aircraft.Info.TurnToDock || !aircraft.Info.VTOL)
-					facing = aircraft.Info.InitialFacing;
+				var offset = WVec.Zero;
+				if (exit != null)
+				{
+					offset = exit.Info.SpawnOffset;
+					facing = exit.Info.Facing;
+				}
 
 				aircraft.MakeReservation(dest);
 				QueueChild(new Land(self, Target.FromActor(dest), offset, facing, Color.Green));

OpenRA.Mods.Common/Traits/Air/Aircraft.cs

@@ -114,9 +114,6 @@ namespace OpenRA.Mods.Common.Traits
 		[Desc("Does this VTOL actor need to turn before landing (on terrain)?")]
 		public readonly bool TurnToLand = false;
 
-		[Desc("Does this VTOL actor need to turn before landing on a resupplier?")]
-		public readonly bool TurnToDock = true;
-
 		[Desc("Does this actor automatically take off after resupplying?")]
 		public readonly bool TakeOffOnResupply = false;
 

OpenRA.Mods.Common/UpdateRules/Rules/RemoveTurnToDock.cs

@@ -0,0 +1,61 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2020 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;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace OpenRA.Mods.Common.UpdateRules.Rules
+{
+	public class RemoveTurnToDock : UpdateRule
+	{
+		public override string Name { get { return "TurnToDock is removed from the Aircraft trait."; } }
+		public override string Description
+		{
+			get
+			{
+				return "TurnToDock is removed from the Aircraft trait in favor of letting the Exit trait on the host" +
+					"building determine whether or not turning is required and to what facing the aircraft must turn.";
+			}
+		}
+
+		readonly List<Tuple<string, string>> turningAircraft = new List<Tuple<string, string>>();
+
+		public override IEnumerable<string> AfterUpdate(ModData modData)
+		{
+			var message = "TurnToDock is now deprecated. The following actors had TurnToDock enabled:\n"
+				+ UpdateUtils.FormatMessageList(turningAircraft.Select(n => n.Item1 + " (" + n.Item2 + ")"))
+				+ "\n If you wish these units to keep their turning behaviour when docking with a host building" +
+					"you will need to define a 'Facing' parameter on the 'Exit' trait of the host building. This change" +
+					"does not affect the behaviour for landing on terrain which is governed by TurnToLand.";
+
+			if (turningAircraft.Any())
+				yield return message;
+
+			turningAircraft.Clear();
+		}
+
+		public override IEnumerable<string> UpdateActorNode(ModData modData, MiniYamlNode actorNode)
+		{
+			var aircraft = actorNode.LastChildMatching("Aircraft");
+			if (aircraft != null)
+			{
+				var turnToDock = aircraft.LastChildMatching("TurnToDock");
+				if (turnToDock != null || turnToDock.NodeValue<bool>())
+					yield break;
+
+				turningAircraft.Add(Tuple.Create(actorNode.Key, actorNode.Location.Filename));
+			}
+
+			yield break;
+		}
+	}
+}

OpenRA.Mods.Common/UpdateRules/UpdatePath.cs

@@ -73,6 +73,7 @@ namespace OpenRA.Mods.Common.UpdateRules
 				new RenameSelfHealing(),
 				new ReplaceBurns(),
 				new RemoveMuzzleSplitFacings(),
+				new RemoveTurnToDock(),
 			})
 		};
 

mods/cnc/rules/defaults.yaml

@@ -329,7 +329,6 @@
 		VTOL: true
 		LandableTerrainTypes: Clear, Rough, Road, Beach, Tiberium, BlueTiberium
 		Crushes: crate, infantry
-		InitialFacing: 896
 		CanSlide: True
 	HiddenUnderFog:
 		Type: GroundPosition

mods/cnc/rules/structures.yaml

@@ -545,6 +545,7 @@ HPAD:
 		Range: 5c0
 	Exit@1:
 		SpawnOffset: 0,-256,0
+		Facing: 896
 	Production:
 		Produces: Aircraft.GDI, Aircraft.Nod
 	Reservable:

mods/d2k/rules/aircraft.yaml

@@ -13,7 +13,6 @@ carryall.reinforce:
 	Aircraft:
 		CruiseAltitude: 2160
 		CruisingCondition: cruising
-		InitialFacing: 0
 		Speed: 144
 		TurnSpeed: 16
 		LandableTerrainTypes: Sand, Rock, Transition, Spice, SpiceSand, Dune, Concrete

mods/ra/rules/aircraft.yaml

@@ -84,7 +84,6 @@ MIG:
 		OpportunityFire: False
 	Aircraft:
 		CruiseAltitude: 2560
-		InitialFacing: 768
 		TurnSpeed: 16
 		Speed: 223
 		RepulsionSpeed: 40
@@ -158,7 +157,6 @@ YAK:
 		OpportunityFire: False
 	Aircraft:
 		CruiseAltitude: 2560
-		InitialFacing: 768
 		TurnSpeed: 16
 		Speed: 178
 		RepulsionSpeed: 40

mods/ra/rules/defaults.yaml

@@ -617,7 +617,6 @@
 		VTOL: true
 		LandableTerrainTypes: Clear, Rough, Road, Ore, Beach, Gems
 		Crushes: crate, mine, infantry
-		InitialFacing: 896
 		CanSlide: True
 	GpsDot:
 		String: Helicopter

mods/ts/rules/aircraft.yaml

@@ -12,7 +12,6 @@ DPOD:
 		Roll: 0
 		TurnSpeed: 20
 		Speed: 149
-		InitialFacing: 0
 	Health:
 		HP: 6000
 	Armor:
@@ -98,7 +97,6 @@ DSHP:
 		Roll: 0
 		TurnSpeed: 20
 		Speed: 168
-		InitialFacing: 0
 		TakeoffSounds: dropup1.aud
 		LandingSounds: dropdwn1.aud
 		IdealSeparation: 1275
@@ -266,7 +264,6 @@ ORCATRAN:
 	Aircraft:
 		TurnSpeed: 20
 		Speed: 84
-		InitialFacing: 0
 		LandableTerrainTypes: Clear, Road, Rail, DirtRoad, Rough, Tiberium, BlueTiberium, Veins
 		Crushes: crate, infantry
 		TakeoffSounds: orcaup1.aud
@@ -308,7 +305,6 @@ TRNSPORT:
 	Aircraft:
 		TurnSpeed: 20
 		Speed: 149
-		InitialFacing: 0
 		Pitch: 0
 		Roll: 0
 		TakeoffSounds: dropup1.aud

mods/ts/rules/defaults.yaml

@@ -875,7 +875,6 @@
 		RepairActors: gadept
 		Voice: Move
 	Aircraft:
-		InitialFacing: 896
 		AirborneCondition: airborne
 		CruisingCondition: cruising
 		CruiseAltitude: 4c704

mods/ts/rules/gdi-structures.yaml

@@ -266,6 +266,7 @@ GAHPAD:
 		MaxHeightDelta: 3
 	Exit@1:
 		SpawnOffset: 0,-256,0
+		Facing: 896
 	ExitsDebugOverlay:
 	RallyPoint:
 		Palette: mouse

mods/ts/rules/nod-structures.yaml

@@ -241,6 +241,7 @@ NAHPAD:
 		MaxHeightDelta: 3
 	Exit@1:
 		SpawnOffset: 0,-256,0
+		Facing: 896
 	ExitsDebugOverlay:
 	RallyPoint:
 		Palette: mouse