rename FlyCircle -> FlyAttackLoop, for accuracy; new FlyCircleto fly a hold

OpenRA.Mods.RA/Air/FlyCircle.cs

@@ -0,0 +1,43 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2011 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.Traits;
+using OpenRA.Traits.Activities;
+
+namespace OpenRA.Mods.RA.Air
+{
+    public class FlyCircle : CancelableActivity
+    {
+        public override IActivity Tick(Actor self)
+        {
+            var cruiseAltitude = self.Info.Traits.Get<PlaneInfo>().CruiseAltitude;
+
+            if (IsCanceled) return NextActivity;
+
+            var aircraft = self.Trait<Aircraft>();
+
+            var desiredFacing = aircraft.Facing + 64;   // we can't possibly turn this fast.
+            if (aircraft.Altitude == cruiseAltitude)
+                aircraft.Facing = Util.TickFacing(aircraft.Facing, desiredFacing, aircraft.ROT);
+
+            if (aircraft.Altitude < cruiseAltitude)
+                ++aircraft.Altitude;
+
+            FlyUtil.Fly(self, cruiseAltitude);
+            return this;
+        }
+
+        public override IEnumerable<float2> GetCurrentPath()
+        {
+            yield break;
+        }
+    }
+}