unit influence blocks building

OpenRa.DataStructures/TypeDictionary.cs

@@ -33,6 +33,13 @@ namespace OpenRa
 			return (T)inner[ typeof( T ) ];
 		}
 
+		public T GetOrDefault<T>()
+		{
+			object o = null;
+			inner.TryGetValue(typeof(T), out o);
+			return (T)o;
+		}
+
 		public IEnumerable<T> WithInterface<T>()
 		{
 			foreach( var i in inner )

OpenRa.Game/BuildingInfluenceMap.cs

@@ -14,7 +14,7 @@ namespace OpenRa.Game
 		readonly int maxDistance;	/* clip limit for voronoi cells */
 		static readonly Pair<Actor, float> NoClaim = Pair.New((Actor)null, float.MaxValue);
 
-		public BuildingInfluenceMap(World world, int maxDistance)
+		public BuildingInfluenceMap(int maxDistance)
 		{
 			this.maxDistance = maxDistance;
 
@@ -22,9 +22,9 @@ namespace OpenRa.Game
 				for (int i = 0; i < 128; i++)
 					influence[i, j] = NoClaim;
 
-			world.ActorAdded +=
+			Game.world.ActorAdded +=
 				a => { if (a.traits.Contains<Traits.Building>()) AddInfluence(a); };
-			world.ActorRemoved +=
+			Game.world.ActorRemoved +=
 				a => { if (a.traits.Contains<Traits.Building>()) RemoveInfluence(a); };
 		}
 

OpenRa.Game/Game.cs

@@ -32,6 +32,7 @@ namespace OpenRa.Game
 
 		public static Player LocalPlayer { get { return players[localPlayerIndex]; } }
 		public static BuildingInfluenceMap BuildingInfluence;
+		public static UnitInfluenceMap UnitInfluence;
 
 		static ISoundEngine soundEngine;
 
@@ -57,7 +58,8 @@ namespace OpenRa.Game
 			foreach (TreeReference treeReference in map.Trees)
 				world.Add(new Actor(treeReference, treeCache, map.Offset));
 
-			BuildingInfluence = new BuildingInfluenceMap(world, 8);
+			BuildingInfluence = new BuildingInfluenceMap(8);
+			UnitInfluence = new UnitInfluenceMap();
 
 			LoadMapBuildings(mapFile);
 			LoadMapUnits(mapFile);
@@ -123,6 +125,7 @@ namespace OpenRa.Game
 		{
 			var stuffFromOtherPlayers = network.Tick();	// todo: actually use the orders!
 			world.Update();
+			UnitInfluence.Tick();
 
 			viewport.DrawRegions();
 		}
@@ -130,6 +133,7 @@ namespace OpenRa.Game
 		public static bool IsCellBuildable(int2 a, UnitMovementType umt)
 		{
 			if (BuildingInfluence.GetBuildingAt(a) != null) return false;
+			if (UnitInfluence.GetUnitAt(a) != null) return false;
 
 			a += map.Offset;
 

OpenRa.Game/OpenRa.Game.csproj

@@ -149,6 +149,7 @@
     <Compile Include="Graphics\Util.cs" />
     <Compile Include="Graphics\Vertex.cs" />
     <Compile Include="Graphics\Viewport.cs" />
+    <Compile Include="UnitInfluenceMap.cs" />
     <Compile Include="UnitOrderGenerator.cs" />
     <Compile Include="VoicePool.cs" />
     <Compile Include="World.cs" />

OpenRa.Game/Traits/Mobile.cs

@@ -63,6 +63,11 @@ namespace OpenRa.Game.Traits
 				currentAction.Cancel(self, this);
 		}
 
+		public IEnumerable<int2> OccupiedCells()
+		{
+			return new[] { fromCell, toCell };
+		}
+	
 		public interface CurrentAction
 		{
 			CurrentAction NextAction { get; set; }

OpenRa.Game/UnitInfluenceMap.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace OpenRa.Game
+{
+	class UnitInfluenceMap
+	{
+		Actor[,] influence = new Actor[128, 128];
+
+		/* todo: incremental updates for great justice [and perf] */
+
+		public void Tick()
+		{
+			influence = new Actor[128, 128];
+
+			var units = Game.world.Actors
+				.Select( a => a.traits.GetOrDefault<Traits.Mobile>() ).Where( m => m != null );
+
+			foreach (var u in units)
+				foreach (var c in u.OccupiedCells())
+					influence[c.X, c.Y] = u.self;
+		}
+
+		public Actor GetUnitAt(int2 a) { return influence[a.X, a.Y]; }
+	}
+}