Added MoveWithinRange activity for Mobile units.

OpenRA.Mods.RA/Activities/MoveAdjacentTo.cs

@@ -17,14 +17,14 @@ namespace OpenRA.Mods.RA.Activities
 {
 	public class MoveAdjacentTo : Activity
 	{
-		readonly Target target;
+		protected readonly Target target;
 		readonly Mobile mobile;
 		readonly PathFinder pathFinder;
 		readonly DomainIndex domainIndex;
 		readonly uint movementClass;
 
+		protected CPos targetPosition;
 		Activity inner;
-		CPos targetPosition;
 		bool repath;
 
 		public MoveAdjacentTo(Actor self, Target target)
@@ -39,6 +39,16 @@ namespace OpenRA.Mods.RA.Activities
 			repath = true;
 		}
 
+		protected virtual bool ShouldStop(Actor self, CPos oldTargetPosition)
+		{
+			return false;
+		}
+
+		protected virtual bool ShouldRepath(Actor self, CPos oldTargetPosition)
+		{
+			return targetPosition != oldTargetPosition;
+		}
+
 		public override Activity Tick(Actor self)
 		{
 			var targetIsValid = target.IsValidFor(self);
@@ -59,15 +69,17 @@ namespace OpenRA.Mods.RA.Activities
 			if (targetIsValid)
 			{
 				// Check if the target has moved
-				var oldPosition = targetPosition;
+				var oldTargetPosition = targetPosition;
 				targetPosition = target.CenterPosition.ToCPos();
-				if (!repath && targetPosition != oldPosition)
+
+				var shroudStop = ShouldStop(self, oldTargetPosition);
+				if (shroudStop || (!repath && ShouldRepath(self, oldTargetPosition)))
 				{
 					// Finish moving into the next cell and then repath.
 					if (inner != null)
 						inner.Cancel(self);
 
-					repath = true;
+					repath = !shroudStop;
 				}
 			}
 			else
@@ -84,9 +96,14 @@ namespace OpenRA.Mods.RA.Activities
 			return this;
 		}
 
+		protected virtual IEnumerable<CPos> CandidateMovementCells(Actor self)
+		{
+			return Util.AdjacentCells(target);
+		}
+
 		void UpdateInnerPath(Actor self)
 		{
-			var targetCells = Util.AdjacentCells(target);
+			var targetCells = CandidateMovementCells(self);
 			var searchCells = new List<CPos>();
 			var loc = self.Location;
 

OpenRA.Mods.RA/Activities/MoveWithinRange.cs

@@ -0,0 +1,63 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2014 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 System.Linq;
+using OpenRA.Mods.RA.Move;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.RA.Activities
+{
+	public class MoveWithinRange : MoveAdjacentTo
+	{
+		readonly WRange maxRange;
+		readonly WRange minRange;
+
+		public MoveWithinRange(Actor self, Target target, WRange minRange, WRange maxRange)
+			: base(self, target)
+		{
+			this.minRange = minRange;
+			this.maxRange = maxRange;
+		}
+
+		protected override bool ShouldStop(Actor self, CPos oldTargetPosition)
+		{
+			// We are now in range. Don't move any further!
+			// HACK: This works around the pathfinder not returning the shortest path
+			var cp = self.CenterPosition;
+			return target.IsInRange(cp, maxRange) && !target.IsInRange(cp, minRange);
+		}
+
+		protected override bool ShouldRepath(Actor self, CPos oldTargetPosition)
+		{
+			var cp = self.CenterPosition;
+			return targetPosition != oldTargetPosition && (!target.IsInRange(cp, maxRange) || target.IsInRange(cp, minRange));
+		}
+
+		protected override IEnumerable<CPos> CandidateMovementCells(Actor self)
+		{
+			var maxCells = (maxRange.Range + 1023) / 1024;
+			var outerCells = self.World.Map.FindTilesInCircle(targetPosition, maxCells);
+
+			var minCells = minRange.Range / 1024;
+			var innerCells = self.World.Map.FindTilesInCircle(targetPosition, minCells);
+
+			var outerSq = maxRange.Range * maxRange.Range;
+			var innerSq = minRange.Range * minRange.Range;
+			var center = target.CenterPosition;
+
+			return outerCells.Except(innerCells).Where(c =>
+			{
+				var dxSq = (c.CenterPosition - center).HorizontalLengthSquared;
+				return dxSq >= innerSq && dxSq <= outerSq;
+			});
+		}
+	}
+}

OpenRA.Mods.RA/OpenRA.Mods.RA.csproj

@@ -528,6 +528,7 @@
     <Compile Include="Console\PlayerCommands.cs" />
     <Compile Include="Render\WithRepairAnimation.cs" />
     <Compile Include="Render\WithRepairOverlay.cs" />
+    <Compile Include="Activities\MoveWithinRange.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\OpenRA.Game\OpenRA.Game.csproj">