Use named pathfinding constants.

- Rename CostForInvalidCell to PathCostForInvalidPath
- Add MovementCostForUnreachableCell
- Update usages of int.MaxValue and short.Maxvalue to use named constants where relevant.
- Update costs on ICustomMovementLayer to return short, for consistency with costs from Locomotor.
- Rename some methods to distinguish between path/movement cost.

OpenRA.Mods.Common/Activities/FindAndDeliverResources.cs

@@ -191,7 +191,7 @@ namespace OpenRA.Mods.Common.Activities
 				.WithCustomCost(loc =>
 				{
 					if ((loc - searchFromLoc).LengthSquared > searchRadiusSquared)
-						return PathGraph.CostForInvalidCell;
+						return PathGraph.PathCostForInvalidPath;
 
 					// Add a cost modifier to harvestable cells to prefer resources that are closer to the refinery.
 					// This reduces the tendancy for harvesters to move in straight lines

OpenRA.Mods.Common/Pathfinder/CellInfoLayerPool.cs

@@ -25,7 +25,7 @@ namespace OpenRA.Mods.Common.Pathfinder
 		{
 			defaultLayer =
 				CellLayer<CellInfo>.CreateInstance(
-					mpos => new CellInfo(int.MaxValue, int.MaxValue, mpos.ToCPos(map), CellStatus.Unvisited),
+					mpos => new CellInfo(PathGraph.PathCostForInvalidPath, PathGraph.PathCostForInvalidPath, mpos.ToCPos(map), CellStatus.Unvisited),
 					new Size(map.MapSize.X, map.MapSize.Y),
 					map.Grid.Type);
 		}

OpenRA.Mods.Common/Pathfinder/PathGraph.cs

@@ -75,7 +75,8 @@ namespace OpenRA.Mods.Common.Pathfinder
 
 	sealed class PathGraph : IGraph<CellInfo>
 	{
-		public const int CostForInvalidCell = int.MaxValue;
+		public const int PathCostForInvalidPath = int.MaxValue;
+		public const short MovementCostForUnreachableCell = short.MaxValue;
 
 		public Actor Actor { get; private set; }
 		public World World { get; private set; }
@@ -147,11 +148,11 @@ namespace OpenRA.Mods.Common.Pathfinder
 			{
 				var dir = directions[i];
 				var neighbor = position + dir;
-				var movementCost = GetCostToNode(neighbor, dir);
+				var pathCost = GetPathCostToNode(neighbor, dir);
 
 				// PERF: Skip closed cells already, 15% of all cells
-				if (movementCost != CostForInvalidCell && info[neighbor].Status != CellStatus.Closed)
+				if (pathCost != PathCostForInvalidPath && info[neighbor].Status != CellStatus.Closed)
-					validNeighbors.Add(new GraphConnection(neighbor, movementCost));
+					validNeighbors.Add(new GraphConnection(neighbor, pathCost));
 			}
 
 			if (posLayer == 0)
@@ -160,7 +161,7 @@ namespace OpenRA.Mods.Common.Pathfinder
 				{
 					var layerPosition = new CPos(position.X, position.Y, cli.Layer.Index);
 					var entryCost = cli.Layer.EntryMovementCost(locomotor.Info, layerPosition);
-					if (entryCost != CostForInvalidCell)
+					if (entryCost != MovementCostForUnreachableCell)
 						validNeighbors.Add(new GraphConnection(layerPosition, entryCost));
 				}
 			}
@@ -168,23 +169,23 @@ namespace OpenRA.Mods.Common.Pathfinder
 			{
 				var layerPosition = new CPos(position.X, position.Y, 0);
 				var exitCost = customLayerInfo[posLayer].Layer.ExitMovementCost(locomotor.Info, layerPosition);
-				if (exitCost != CostForInvalidCell)
+				if (exitCost != MovementCostForUnreachableCell)
 					validNeighbors.Add(new GraphConnection(layerPosition, exitCost));
 			}
 
 			return validNeighbors;
 		}
 
-		int GetCostToNode(CPos destNode, CVec direction)
+		int GetPathCostToNode(CPos destNode, CVec direction)
 		{
 			var movementCost = locomotor.MovementCostToEnterCell(Actor, destNode, checkConditions, IgnoreActor);
-			if (movementCost != short.MaxValue && !(CustomBlock != null && CustomBlock(destNode)))
+			if (movementCost != MovementCostForUnreachableCell && !(CustomBlock != null && CustomBlock(destNode)))
-				return CalculateCellCost(destNode, direction, movementCost);
+				return CalculateCellPathCost(destNode, direction, movementCost);
 
-			return CostForInvalidCell;
+			return PathCostForInvalidPath;
 		}
 
-		int CalculateCellCost(CPos neighborCPos, CVec direction, int movementCost)
+		int CalculateCellPathCost(CPos neighborCPos, CVec direction, int movementCost)
 		{
 			var cellCost = movementCost;
 
@@ -194,8 +195,8 @@ namespace OpenRA.Mods.Common.Pathfinder
 			if (CustomCost != null)
 			{
 				var customCost = CustomCost(neighborCPos);
-				if (customCost == CostForInvalidCell)
+				if (customCost == PathCostForInvalidPath)
-					return CostForInvalidCell;
+					return PathCostForInvalidPath;
 
 				cellCost += customCost;
 			}
@@ -206,7 +207,7 @@ namespace OpenRA.Mods.Common.Pathfinder
 				var heightLayer = World.Map.Height;
 				var from = neighborCPos - direction;
 				if (Math.Abs(heightLayer[neighborCPos] - heightLayer[from]) > 1)
-					return CostForInvalidCell;
+					return PathCostForInvalidPath;
 			}
 
 			// Directional bonuses for smoother flow!

OpenRA.Mods.Common/Pathfinder/PathSearch.cs

@@ -108,7 +108,7 @@ namespace OpenRA.Mods.Common.Pathfinder
 			var currentCell = Graph[currentMinNode];
 			Graph[currentMinNode] = new CellInfo(currentCell.CostSoFar, currentCell.EstimatedTotal, currentCell.PreviousPos, CellStatus.Closed);
 
-			if (Graph.CustomCost != null && Graph.CustomCost(currentMinNode) == PathGraph.CostForInvalidCell)
+			if (Graph.CustomCost != null && Graph.CustomCost(currentMinNode) == PathGraph.PathCostForInvalidPath)
 				return currentMinNode;
 
 			foreach (var connection in Graph.GetConnections(currentMinNode))

OpenRA.Mods.Common/Traits/Buildings/TransformsIntoMobile.cs

@@ -12,6 +12,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Mods.Common.Activities;
+using OpenRA.Mods.Common.Pathfinder;
 using OpenRA.Primitives;
 using OpenRA.Traits;
 
@@ -210,7 +211,7 @@ namespace OpenRA.Mods.Common.Traits
 
 			bool CanEnterCell(Actor self, CPos cell)
 			{
-				if (mobile.locomotor.MovementCostForCell(cell) == short.MaxValue)
+				if (mobile.locomotor.MovementCostForCell(cell) == PathGraph.MovementCostForUnreachableCell)
 					return false;
 
 				return mobile.locomotor.CanMoveFreelyInto(self, cell, BlockedByActor.All, null);

OpenRA.Mods.Common/Traits/Harvester.cs

@@ -206,7 +206,7 @@ namespace OpenRA.Mods.Common.Traits
 
 					// Too many harvesters clogs up the refinery's delivery location:
 					if (occupancy >= Info.MaxUnloadQueue)
-						return PathGraph.CostForInvalidCell;
+						return PathGraph.PathCostForInvalidPath;
 
 					// Prefer refineries with less occupancy (multiplier is to offset distance cost):
 					return occupancy * Info.UnloadQueueCostModifier;

OpenRA.Mods.Common/Traits/Mobile.cs

@@ -119,7 +119,7 @@ namespace OpenRA.Mods.Common.Traits
 				locomotor = world.WorldActor.TraitsImplementing<Locomotor>()
 				   .SingleOrDefault(l => l.Info.Name == Locomotor);
 
-			if (locomotor.MovementCostForCell(cell) == short.MaxValue)
+			if (locomotor.MovementCostForCell(cell) == PathGraph.MovementCostForUnreachableCell)
 				return false;
 
 			return locomotor.CanMoveFreelyInto(self, cell, subCell, check, ignoreActor);
@@ -520,7 +520,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		public bool CanExistInCell(CPos cell)
 		{
-			return Locomotor.MovementCostForCell(cell) != short.MaxValue;
+			return Locomotor.MovementCostForCell(cell) != PathGraph.MovementCostForUnreachableCell;
 		}
 
 		public bool CanEnterCell(CPos cell, Actor ignoreActor = null, BlockedByActor check = BlockedByActor.All)
@@ -1020,7 +1020,7 @@ namespace OpenRA.Mods.Common.Traits
 				if (mobile.IsTraitPaused
 					|| !self.World.Map.Contains(location)
 					|| (!explored && !locomotorInfo.MoveIntoShroud)
-					|| (explored && mobile.Locomotor.MovementCostForCell(location) == short.MaxValue))
+					|| (explored && mobile.Locomotor.MovementCostForCell(location) == PathGraph.MovementCostForUnreachableCell))
 					cursor = mobile.Info.BlockedCursor;
 				else if (!explored || !mobile.Info.TerrainCursors.TryGetValue(self.World.Map.GetTerrainInfo(location).Type, out cursor))
 					cursor = mobile.Info.Cursor;

OpenRA.Mods.Common/Traits/World/ElevatedBridgeLayer.cs

@@ -80,14 +80,14 @@ namespace OpenRA.Mods.Common.Traits
 			return cellCenters[cell];
 		}
 
-		int ICustomMovementLayer.EntryMovementCost(LocomotorInfo li, CPos cell)
+		short ICustomMovementLayer.EntryMovementCost(LocomotorInfo li, CPos cell)
 		{
-			return ends.Contains(cell) ? 0 : PathGraph.CostForInvalidCell;
+			return ends.Contains(cell) ? (short)0 : PathGraph.MovementCostForUnreachableCell;
 		}
 
-		int ICustomMovementLayer.ExitMovementCost(LocomotorInfo li, CPos cell)
+		short ICustomMovementLayer.ExitMovementCost(LocomotorInfo li, CPos cell)
 		{
-			return ends.Contains(cell) ? 0 : PathGraph.CostForInvalidCell;
+			return ends.Contains(cell) ? (short)0 : PathGraph.MovementCostForUnreachableCell;
 		}
 
 		byte ICustomMovementLayer.GetTerrainIndex(CPos cell)

OpenRA.Mods.Common/Traits/World/JumpjetActorLayer.cs

@@ -87,16 +87,16 @@ namespace OpenRA.Mods.Common.Traits
 			return map.Ramp[cell] == 0;
 		}
 
-		int ICustomMovementLayer.EntryMovementCost(LocomotorInfo li, CPos cell)
+		short ICustomMovementLayer.EntryMovementCost(LocomotorInfo li, CPos cell)
 		{
 			var jli = (JumpjetLocomotorInfo)li;
-			return ValidTransitionCell(cell, jli) ? jli.JumpjetTransitionCost : PathGraph.CostForInvalidCell;
+			return ValidTransitionCell(cell, jli) ? jli.JumpjetTransitionCost : PathGraph.MovementCostForUnreachableCell;
 		}
 
-		int ICustomMovementLayer.ExitMovementCost(LocomotorInfo li, CPos cell)
+		short ICustomMovementLayer.ExitMovementCost(LocomotorInfo li, CPos cell)
 		{
 			var jli = (JumpjetLocomotorInfo)li;
-			return ValidTransitionCell(cell, jli) ? jli.JumpjetTransitionCost : PathGraph.CostForInvalidCell;
+			return ValidTransitionCell(cell, jli) ? jli.JumpjetTransitionCost : PathGraph.MovementCostForUnreachableCell;
 		}
 
 		byte ICustomMovementLayer.GetTerrainIndex(CPos cell)

OpenRA.Mods.Common/Traits/World/JumpjetLocomotor.cs

@@ -17,7 +17,7 @@ namespace OpenRA.Mods.Common.Traits
 	public class JumpjetLocomotorInfo : LocomotorInfo
 	{
 		[Desc("Pathfinding cost for taking off or landing.")]
-		public readonly int JumpjetTransitionCost = 0;
+		public readonly short JumpjetTransitionCost = 0;
 
 		[Desc("The terrain types that this actor can transition on. Leave empty to allow any.")]
 		public readonly HashSet<string> JumpjetTransitionTerrainTypes = new HashSet<string>();

OpenRA.Mods.Common/Traits/World/Locomotor.cs

@@ -13,6 +13,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Graphics;
+using OpenRA.Mods.Common.Pathfinder;
 using OpenRA.Primitives;
 using OpenRA.Support;
 using OpenRA.Traits;
@@ -109,7 +110,7 @@ namespace OpenRA.Mods.Common.Traits
 
 			public TerrainInfo()
 			{
-				Cost = short.MaxValue;
+				Cost = PathGraph.MovementCostForUnreachableCell;
 				Speed = 0;
 			}
 
@@ -168,13 +169,13 @@ namespace OpenRA.Mods.Common.Traits
 				if (!info.TerrainSpeeds.TryGetValue(terrainInfo.TerrainTypes[i].Type, out terrainInfos[i]))
 					terrainInfos[i] = LocomotorInfo.TerrainInfo.Impassable;
 
-			MovementClass = (uint)terrainInfos.Select(ti => ti.Cost < short.MaxValue).ToBits();
+			MovementClass = (uint)terrainInfos.Select(ti => ti.Cost != PathGraph.MovementCostForUnreachableCell).ToBits();
 		}
 
 		public short MovementCostForCell(CPos cell)
 		{
 			if (!world.Map.Contains(cell))
-				return short.MaxValue;
+				return PathGraph.MovementCostForUnreachableCell;
 
 			return cell.Layer == 0 ? cellsCost[cell] : customLayerCellsCost[cell.Layer][cell];
 		}
@@ -190,13 +191,13 @@ namespace OpenRA.Mods.Common.Traits
 		public short MovementCostToEnterCell(Actor actor, CPos destNode, BlockedByActor check, Actor ignoreActor)
 		{
 			if (!world.Map.Contains(destNode))
-				return short.MaxValue;
+				return PathGraph.MovementCostForUnreachableCell;
 
 			var cellCost = destNode.Layer == 0 ? cellsCost[destNode] : customLayerCellsCost[destNode.Layer][destNode];
 
-			if (cellCost == short.MaxValue ||
+			if (cellCost == PathGraph.MovementCostForUnreachableCell ||
 				!CanMoveFreelyInto(actor, destNode, check, ignoreActor))
-				return short.MaxValue;
+				return PathGraph.MovementCostForUnreachableCell;
 
 			return cellCost;
 		}
@@ -276,7 +277,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		public SubCell GetAvailableSubCell(Actor self, CPos cell, BlockedByActor check, SubCell preferredSubCell = SubCell.Any, Actor ignoreActor = null)
 		{
-			if (MovementCostForCell(cell) == short.MaxValue)
+			if (MovementCostForCell(cell) == PathGraph.MovementCostForUnreachableCell)
 				return SubCell.Invalid;
 
 			if (check > BlockedByActor.None)
@@ -381,7 +382,7 @@ namespace OpenRA.Mods.Common.Traits
 					{
 						var index = cml.GetTerrainIndex(cell);
 
-						var cost = short.MaxValue;
+						var cost = PathGraph.MovementCostForUnreachableCell;
 
 						if (index != byte.MaxValue)
 							cost = terrainInfos[index].Cost;
@@ -416,7 +417,7 @@ namespace OpenRA.Mods.Common.Traits
 				? world.Map.GetTerrainIndex(cell)
 				: world.GetCustomMovementLayers()[cell.Layer].GetTerrainIndex(cell);
 
-			var cost = short.MaxValue;
+			var cost = PathGraph.MovementCostForUnreachableCell;
 
 			if (index != byte.MaxValue)
 				cost = terrainInfos[index].Cost;

OpenRA.Mods.Common/Traits/World/PathFinder.cs

@@ -167,7 +167,7 @@ namespace OpenRA.Mods.Common.Traits
 				// make some progress on the first search
 				var p = fromSrc.Expand();
 				if (fromDest.Graph[p].Status == CellStatus.Closed &&
-					fromDest.Graph[p].CostSoFar < int.MaxValue)
+					fromDest.Graph[p].CostSoFar != PathGraph.PathCostForInvalidPath)
 				{
 					path = MakeBidiPath(fromSrc, fromDest, p);
 					break;
@@ -176,7 +176,7 @@ namespace OpenRA.Mods.Common.Traits
 				// make some progress on the second search
 				var q = fromDest.Expand();
 				if (fromSrc.Graph[q].Status == CellStatus.Closed &&
-					fromSrc.Graph[q].CostSoFar < int.MaxValue)
+					fromSrc.Graph[q].CostSoFar != PathGraph.PathCostForInvalidPath)
 				{
 					path = MakeBidiPath(fromSrc, fromDest, q);
 					break;

OpenRA.Mods.Common/Traits/World/SubterraneanActorLayer.cs

@@ -85,16 +85,16 @@ namespace OpenRA.Mods.Common.Traits
 			return map.Ramp[cell] == 0;
 		}
 
-		int ICustomMovementLayer.EntryMovementCost(LocomotorInfo li, CPos cell)
+		short ICustomMovementLayer.EntryMovementCost(LocomotorInfo li, CPos cell)
 		{
 			var sli = (SubterraneanLocomotorInfo)li;
-			return ValidTransitionCell(cell, sli) ? sli.SubterraneanTransitionCost : PathGraph.CostForInvalidCell;
+			return ValidTransitionCell(cell, sli) ? sli.SubterraneanTransitionCost : PathGraph.MovementCostForUnreachableCell;
 		}
 
-		int ICustomMovementLayer.ExitMovementCost(LocomotorInfo li, CPos cell)
+		short ICustomMovementLayer.ExitMovementCost(LocomotorInfo li, CPos cell)
 		{
 			var sli = (SubterraneanLocomotorInfo)li;
-			return ValidTransitionCell(cell, sli) ? sli.SubterraneanTransitionCost : PathGraph.CostForInvalidCell;
+			return ValidTransitionCell(cell, sli) ? sli.SubterraneanTransitionCost : PathGraph.MovementCostForUnreachableCell;
 		}
 
 		byte ICustomMovementLayer.GetTerrainIndex(CPos cell)

OpenRA.Mods.Common/Traits/World/SubterraneanLocomotor.cs

@@ -17,7 +17,7 @@ namespace OpenRA.Mods.Common.Traits
 	public class SubterraneanLocomotorInfo : LocomotorInfo
 	{
 		[Desc("Pathfinding cost for submerging or reemerging.")]
-		public readonly int SubterraneanTransitionCost = 0;
+		public readonly short SubterraneanTransitionCost = 0;
 
 		[Desc("The terrain types that this actor can transition on. Leave empty to allow any.")]
 		public readonly HashSet<string> SubterraneanTransitionTerrainTypes = new HashSet<string>();
@@ -25,7 +25,7 @@ namespace OpenRA.Mods.Common.Traits
 		[Desc("Can this actor transition on slopes?")]
 		public readonly bool SubterraneanTransitionOnRamps = false;
 
-		[Desc("Depth at which the subterranian condition is applied.")]
+		[Desc("Depth at which the subterranean condition is applied.")]
 		public readonly WDist SubterraneanTransitionDepth = new WDist(-1024);
 
 		public override bool DisableDomainPassabilityCheck => true;

OpenRA.Mods.Common/Traits/World/TerrainTunnelLayer.cs

@@ -79,14 +79,14 @@ namespace OpenRA.Mods.Common.Traits
 			return cellCenters[cell];
 		}
 
-		int ICustomMovementLayer.EntryMovementCost(LocomotorInfo li, CPos cell)
+		short ICustomMovementLayer.EntryMovementCost(LocomotorInfo li, CPos cell)
 		{
-			return portals.Contains(cell) ? 0 : PathGraph.CostForInvalidCell;
+			return portals.Contains(cell) ? (short)0 : PathGraph.MovementCostForUnreachableCell;
 		}
 
-		int ICustomMovementLayer.ExitMovementCost(LocomotorInfo li, CPos cell)
+		short ICustomMovementLayer.ExitMovementCost(LocomotorInfo li, CPos cell)
 		{
-			return portals.Contains(cell) ? 0 : PathGraph.CostForInvalidCell;
+			return portals.Contains(cell) ? (short)0 : PathGraph.MovementCostForUnreachableCell;
 		}
 
 		byte ICustomMovementLayer.GetTerrainIndex(CPos cell)

OpenRA.Mods.Common/TraitsInterfaces.cs

@@ -404,8 +404,8 @@ namespace OpenRA.Mods.Common.Traits
 		bool ReturnToGroundLayerOnIdle { get; }
 
 		bool EnabledForLocomotor(LocomotorInfo li);
-		int EntryMovementCost(LocomotorInfo li, CPos cell);
+		short EntryMovementCost(LocomotorInfo li, CPos cell);
-		int ExitMovementCost(LocomotorInfo li, CPos cell);
+		short ExitMovementCost(LocomotorInfo li, CPos cell);
 
 		byte GetTerrainIndex(CPos cell);
 		WPos CenterOfCell(CPos cell);