moved air unit support to ra

OpenRA.Mods.RA/Activities/HeliLand.cs

@@ -0,0 +1,50 @@
+#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 OpenRA.GameRules;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.RA.Activities
+{
+	class HeliLand : IActivity
+	{
+		public HeliLand(bool requireSpace) { this.requireSpace = requireSpace; }
+
+		bool requireSpace;
+		bool isCanceled;
+		public IActivity NextActivity { get; set; }
+
+		public IActivity Tick(Actor self)
+		{
+			if (isCanceled) return NextActivity;
+			var unit = self.traits.Get<Unit>();
+			if (unit.Altitude == 0)
+				return NextActivity;
+
+			if (requireSpace && !self.World.IsPathableCell(self.Location, UnitMovementType.Foot))
+				return this;	// fail to land if no space
+
+			--unit.Altitude;
+			return this;
+		}
+
+		public void Cancel(Actor self) { isCanceled = true; NextActivity = null; }
+	}
+}