Tweak helicopter movement / attack

OpenRA.Mods.RA/Activities/HeliAttack.cs

@@ -39,8 +39,10 @@ namespace OpenRA.Mods.RA.Activities
 
 			var limitedAmmo = self.traits.GetOrDefault<LimitedAmmo>();
 			if (limitedAmmo != null && !limitedAmmo.HasAmmo())
+			{	
+				self.QueueActivity(new HeliReturn());
 				return NextActivity;
-
+			}
 			var unit = self.traits.Get<Unit>();
 
 			var info = self.Info.Traits.Get<HelicopterInfo>();

OpenRA.Mods.RA/Activities/HeliFly.cs

@@ -21,6 +21,7 @@
 using System;
 using OpenRA.GameRules;
 using OpenRA.Traits;
+using System.Linq;
 
 namespace OpenRA.Mods.RA.Activities
 {
@@ -49,7 +50,15 @@ namespace OpenRA.Mods.RA.Activities
 				return this;
 			}
 			
-			var dist = Dest - self.CenterLocation;
+			// Prevent multiple units from stacking together
+			var otherHelis = self.World.FindUnitsInCircle(self.CenterLocation, info.IdealSeparation)
+				.Where(a => a.traits.Contains<Helicopter>());
+			
+			var f = otherHelis
+				.Select(h => GetRepulseForce(self, h))
+				.Aggregate(float2.Zero, (a, b) => a + b);
+			
+			var dist = Dest - self.CenterLocation + f;
 			if (float2.WithinEpsilon(float2.Zero, dist, 2))
 			{
 				self.CenterLocation = Dest;
@@ -68,6 +77,19 @@ namespace OpenRA.Mods.RA.Activities
 			return this;
 		}
 		
+		// Todo: Duplicated from HeliAttack
+		const float Epsilon = .5f;
+		float2 GetRepulseForce(Actor self, Actor h)
+		{
+			if (self == h)
+				return float2.Zero;
+			var d = self.CenterLocation - h.CenterLocation;
+			if (d.LengthSquared < Epsilon)
+				return float2.FromAngle((float)self.World.SharedRandom.NextDouble() * 3.14f);
+
+			return (2 / d.LengthSquared) * d;
+		}
+
 		public void Cancel(Actor self) { isCanceled = true; NextActivity = null; }
 	}
 }

OpenRA.Mods.RA/AttackHeli.cs

@@ -1,4 +1,4 @@
-#region Copyright & License Information
+#region Copyright & License Information
 /*
  * Copyright 2007,2009,2010 Chris Forbes, Robert Pepperell, Matthew Bowra-Dean, Paul Chote, Alli Witheford.
  * This file is part of OpenRA.
@@ -37,7 +37,7 @@ namespace OpenRA.Mods.RA
 		{
 			target = order.TargetActor;
 			self.QueueActivity(new HeliAttack(order.TargetActor));
-			self.QueueActivity(new HeliReturn());
+			//self.QueueActivity(new HeliReturn());
 		}
 	}
 }

OpenRA.Mods.RA/Helicopter.cs

@@ -33,6 +33,7 @@ namespace OpenRA.Mods.RA
 		public readonly string[] RearmBuildings = { "hpad" };
 		public readonly int CruiseAltitude = 20;
 		public readonly int IdealSeparation = 80;
+		public readonly bool LandWhenIdle = true;
 		public object Create(Actor self) { return new Helicopter(self); }
 	}
 
@@ -78,9 +79,13 @@ namespace OpenRA.Mods.RA
 			{
 				self.CancelActivity();
 				self.QueueActivity(new HeliFly(Util.CenterOfCell(order.TargetLocation)));
+				
+				if (self.Info.Traits.Get<HelicopterInfo>().LandWhenIdle)
+				{
 					self.QueueActivity(new Turn(self.Info.Traits.GetOrDefault<UnitInfo>().InitialFacing));
 					self.QueueActivity(new HeliLand(true));
 				}
+			}
 
 			if (order.OrderString == "Enter")
 			{

mods/cnc/vehicles.yaml

@@ -418,7 +418,7 @@ HELI:
 	Buildable:
 		Icon: heliicnh
 		BuildPaletteOrder: 60
-		Prerequisites: hpad
+		Prerequisites: hpad, hq
 		BuiltAt: hpad
 		Owner: nod
 		Cost: 1200
@@ -438,6 +438,7 @@ HELI:
 		PrimaryOffset: -5,0,0,2
 		SecondaryOffset: 5,0,0,2
 	Helicopter:
+		LandWhenIdle: no
 	RenderUnitRotor:
 		PrimaryOffset: 0,0,0,-2
 	WithShadow:
@@ -449,7 +450,7 @@ ORCA:
 	Buildable:
 		Icon: orcaicnh
 		BuildPaletteOrder: 60
-		Prerequisites: hpad
+		Prerequisites: hpad, hq
 		BuiltAt: hpad
 		Owner: gdi
 		Cost: 1200
@@ -469,6 +470,7 @@ ORCA:
 		PrimaryOffset: -5,0,0,2
 		SecondaryOffset: 5,0,0,2
 	Helicopter:
+		LandWhenIdle: no
 	RenderUnit:
 	WithShadow:
 	LimitedAmmo: