new heli movement

OpenRa.Game/Traits/Activities/HeliFly.cs

@@ -0,0 +1,49 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace OpenRa.Game.Traits.Activities
+{
+	class HeliFly : IActivity
+	{
+		const int CruiseAltitude = 20;
+		readonly float2 Dest;
+		public HeliFly(float2 dest)
+		{
+			Dest = dest;
+		}
+
+		public IActivity NextActivity { get; set; }
+		bool isCanceled;
+		
+		public IActivity Tick(Actor self)
+		{
+			if (isCanceled)
+				return NextActivity;
+
+			var unit = self.traits.Get<Unit>();
+
+			if (unit.Altitude != CruiseAltitude)
+			{
+				unit.Altitude += Math.Sign(CruiseAltitude - unit.Altitude);
+				return this;
+			}
+
+			var dist = Dest - self.CenterLocation;
+			if (float2.WithinEpsilon(float2.Zero, dist, 10))
+				return NextActivity;
+
+			var desiredFacing = Util.GetFacing(dist, unit.Facing);
+			Util.TickFacing(ref unit.Facing, desiredFacing, self.Info.ROT);
+
+			var rawSpeed = .2f * Util.GetEffectiveSpeed(self);
+			self.CenterLocation += (rawSpeed / dist.Length) * dist;
+			self.Location = ((1 / 24f) * self.CenterLocation).ToInt2();
+
+			return this;
+		}
+
+		public void Cancel(Actor self) { isCanceled = true; NextActivity = null; }
+	}
+}