moved air unit support to ra

OpenRA.Mods.RA/Activities/HeliAttack.cs

@@ -0,0 +1,92 @@
+#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.
+ * 
+ *  OpenRA is free software: you can redistribute it and/or modify
+ *  it 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.
+ * 
+ *  OpenRA is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ * 
+ *  You should have received a copy of the GNU General Public License
+ *  along with OpenRA.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#endregion
+
+using System;
+using System.Linq;
+using OpenRA.GameRules;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.RA.Activities
+{
+	public class HeliAttack : IActivity
+	{
+		Actor target;
+		public HeliAttack( Actor target ) { this.target = target; }
+
+		public IActivity NextActivity { get; set; }
+
+		public IActivity Tick(Actor self)
+		{
+			if (target == null || target.IsDead)
+				return NextActivity;
+
+			var limitedAmmo = self.traits.GetOrDefault<LimitedAmmo>();
+			if (limitedAmmo != null && !limitedAmmo.HasAmmo())
+				return NextActivity;
+
+			var unit = self.traits.Get<Unit>();
+
+			var info = self.Info.Traits.Get<HelicopterInfo>();
+			if (unit.Altitude != info.CruiseAltitude)
+			{
+				unit.Altitude += Math.Sign(info.CruiseAltitude - unit.Altitude);
+				return this;
+			}
+
+			var range = self.GetPrimaryWeapon().Range - 1;
+			var dist = target.CenterLocation - self.CenterLocation;
+
+			var desiredFacing = Util.GetFacing(dist, unit.Facing);
+			Util.TickFacing(ref unit.Facing, desiredFacing, self.Info.Traits.Get<UnitInfo>().ROT);
+
+			var rawSpeed = .2f * Util.GetEffectiveSpeed(self, UnitMovementType.Fly);
+
+			if (!float2.WithinEpsilon(float2.Zero, dist, range * Game.CellSize))
+				self.CenterLocation += (rawSpeed / dist.Length) * dist;
+
+			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);
+
+			self.CenterLocation += rawSpeed * f;
+
+			self.Location = ((1 / 24f) * self.CenterLocation).ToInt2();
+
+			return this;
+		}
+
+		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) { target = null; NextActivity = null; }
+	}
+}