Optimize AI expansion logic: refine base limit, placement priority, and expansion radius

Author: jmctsh

OpenRA.Launcher/OpenRA.Launcher.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>Exe</OutputType>
     <AssemblyName>OpenRA</AssemblyName>
@@ -24,6 +24,7 @@
   <ItemGroup>
     <None Include="App.config" />
     <ProjectReference Include="..\OpenRA.Game\OpenRA.Game.csproj" />
+    <ProjectReference Include="..\OpenRA.Platforms.Default\OpenRA.Platforms.Default.csproj" />
     <AdditionalFiles Include="Properties/launchSettings.json" />
   </ItemGroup>
 </Project>

OpenRA.Mods.Common/ServerCommands.cs

@@ -882,6 +882,16 @@ public static string ManageProductionCommand(JObject json, World world)
 			}
 		}
 
+		public static string ExpandBaseCommand(JObject json, World world)
+		{
+			var player = ResolvePlayer(json, world);
+			var expansionManager = player.PlayerActor.TraitOrDefault<CopilotExpansionManager>();
+			if (expansionManager == null)
+				return "Player does not have CopilotExpansionManager trait.";
+
+			expansionManager.StartExpansion(player);
+			return "Base expansion started.";
+		}
 
 		public static string PlaceBuildingCommand(JObject json, World world)
 		{
@@ -1563,6 +1573,7 @@ public void WorldLoaded(World w, WorldRenderer wr)
 
 				w.CopilotServer.CommandHandlers["place_building"] = PlaceBuildingCommand;
 				w.CopilotServer.CommandHandlers["manage_production"] = ManageProductionCommand;
+				w.CopilotServer.CommandHandlers["expand_base"] = ExpandBaseCommand;
 				w.CopilotServer.QueryHandlers["start_production"] = StartProductionCommand;
 
 				w.CopilotServer.QueryHandlers["query_actor"] = ActorQueryCommand;

OpenRA.Mods.Common/Traits/BotModules/BaseBuilderBotModule.cs

@@ -74,7 +74,7 @@ public class BaseBuilderBotModuleInfo : ConditionalTraitInfo
 		public readonly int InititalMinimumRefineryCount = 1;
 
 		[Desc("Number of refineries to build additionally after building a barracks.")]
-		public readonly int AdditionalMinimumRefineryCount = 1;
+		public readonly int AdditionalMinimumRefineryCount = 2;
 
 		[Desc("Additional delay (in ticks) between structure production checks when there is no active production.",
 			"StructureProductionRandomBonusDelay is added to this.")]
@@ -149,6 +149,14 @@ public CPos GetRandomBaseCenter()
 			return randomConstructionYard?.Location ?? initialBaseCenter;
 		}
 
+		public IEnumerable<Actor> GetBaseActors()
+		{
+			if (constructionYardBuildings.Actors.Any())
+				return constructionYardBuildings.Actors;
+
+			return Enumerable.Empty<Actor>();
+		}
+
 		public CPos DefenseCenter { get; private set; }
 
 		// Actor, ActorCount.
@@ -319,10 +327,23 @@ public bool HasAdequateRefineryCount() =>
 			AIUtils.CountActorByCommonName(powerBuildings) == 0 ||
 			AIUtils.CountActorByCommonName(constructionYardBuildings) == 0;
 
-		int MinimumRefineryCount() =>
-			AIUtils.CountActorByCommonName(barracksBuildings) > 0
-			? Info.InititalMinimumRefineryCount + Info.AdditionalMinimumRefineryCount
-			: Info.InititalMinimumRefineryCount;
+		public int MinimumRefineryCount()
+		{
+			var baseCount = System.Math.Max(1, AIUtils.CountActorByCommonName(constructionYardBuildings));
+			
+			// Start with initial count
+			var count = Info.InititalMinimumRefineryCount;
+			
+			// If we have barracks, add additional count
+			if (AIUtils.CountActorByCommonName(barracksBuildings) > 0)
+				count += Info.AdditionalMinimumRefineryCount;
+
+			// For every additional base beyond the first, add 3 refineries
+			if (baseCount > 1)
+				count += (baseCount - 1) * 3;
+
+			return count;
+		}
 
 		List<MiniYamlNode> IGameSaveTraitData.IssueTraitData(Actor self)
 		{

OpenRA.Mods.Common/Traits/BotModules/BotModuleLogic/BaseBuilderQueueManager.cs

@@ -223,6 +223,10 @@ ActorInfo GetProducibleBuilding(HashSet<string> actors, IEnumerable<ActorInfo> b
 				if (!baseBuilder.Info.BuildingLimits.TryGetValue(actor.Name, out var limit))
 					return true;
 
+				// Allow dynamic refinery count to override static limits from YAML
+				if (baseBuilder.Info.RefineryTypes.Contains(actor.Name))
+					limit = Math.Max(limit, baseBuilder.MinimumRefineryCount());
+
 				return playerBuildings.Count(a => a.Info.Name == actor.Name) < limit;
 			});
 
@@ -470,44 +474,77 @@ ActorInfo ChooseBuildingToBuild(ProductionQueue queue)
 				return (null, 0);
 			}
 
-			var baseCenter = baseBuilder.GetRandomBaseCenter();
+			var baseActors = baseBuilder.GetBaseActors();
+			var baseLocations = new List<CPos>();
 
-			switch (type)
+			if (baseActors.Any())
 			{
-				case BuildingType.Defense:
+				// Strategy:
+				// Refinery: Prioritize the newest base (highest ActorID) to support expansion economy.
+				// Others: Randomize to distribute buildings.
+				if (type == BuildingType.Refinery)
+				{
+					baseLocations.AddRange(baseActors.OrderByDescending(a => a.ActorID).Select(a => a.Location));
+				}
+				else
+				{
+					baseLocations.AddRange(baseActors.Select(a => a.Location).Shuffle(world.LocalRandom));
+				}
+			}
+			else
+			{
+				// Fallback if no construction yards (e.g. only initial base center known)
+				baseLocations.Add(baseBuilder.GetRandomBaseCenter());
+			}
 
-					// Build near the closest enemy structure
-					var closestEnemy = world.ActorsHavingTrait<Building>()
-						.Where(a => !a.Disposed && player.RelationshipWith(a.Owner) == PlayerRelationship.Enemy)
-						.ClosestToIgnoringPath(world.Map.CenterOfCell(baseBuilder.DefenseCenter));
+			foreach (var baseCenter in baseLocations)
+			{
+				switch (type)
+				{
+					case BuildingType.Defense:
 
-					var targetCell = closestEnemy != null ? closestEnemy.Location : baseCenter;
+						// Build near the closest enemy structure
+						var closestEnemy = world.ActorsHavingTrait<Building>()
+							.Where(a => !a.Disposed && player.RelationshipWith(a.Owner) == PlayerRelationship.Enemy)
+							.ClosestToIgnoringPath(world.Map.CenterOfCell(baseBuilder.DefenseCenter));
 
-					return FindPos(baseBuilder.DefenseCenter, targetCell, baseBuilder.Info.MinimumDefenseRadius, baseBuilder.Info.MaximumDefenseRadius);
+						var targetCell = closestEnemy != null ? closestEnemy.Location : baseCenter;
 
-				case BuildingType.Refinery:
+						// Defense placement is usually centered around DefenseCenter, but we use baseCenter as fallback target if no enemy.
+						// Note: If we really want to support multiple defense centers, that would require larger changes.
+						// For now, we return immediately for Defense as it uses global DefenseCenter.
+						return FindPos(baseBuilder.DefenseCenter, targetCell, baseBuilder.Info.MinimumDefenseRadius, baseBuilder.Info.MaximumDefenseRadius);
 
-					// Try and place the refinery near a resource field
-					if (resourceLayer != null)
-					{
-						var nearbyResources = world.Map.FindTilesInAnnulus(baseCenter, baseBuilder.Info.MinBaseRadius, baseBuilder.Info.MaxBaseRadius)
-							.Where(a => resourceLayer.GetResource(a).Type != null)
-							.Shuffle(world.LocalRandom).Take(baseBuilder.Info.MaxResourceCellsToCheck);
+					case BuildingType.Refinery:
 
-						foreach (var r in nearbyResources)
+						// Try and place the refinery near a resource field
+						if (resourceLayer != null)
 						{
-							var found = FindPos(baseCenter, r, baseBuilder.Info.MinBaseRadius, baseBuilder.Info.MaxBaseRadius);
-							if (found.Location != null)
-								return found;
-						}
-					}
+							var nearbyResources = world.Map.FindTilesInAnnulus(baseCenter, baseBuilder.Info.MinBaseRadius, baseBuilder.Info.MaxBaseRadius)
+								.Where(a => resourceLayer.GetResource(a).Type != null)
+								.Shuffle(world.LocalRandom).Take(baseBuilder.Info.MaxResourceCellsToCheck);
 
-					// Try and find a free spot somewhere else in the base
-					return FindPos(baseCenter, baseCenter, baseBuilder.Info.MinBaseRadius, baseBuilder.Info.MaxBaseRadius);
+							foreach (var r in nearbyResources)
+							{
+								var found = FindPos(baseCenter, r, baseBuilder.Info.MinBaseRadius, baseBuilder.Info.MaxBaseRadius);
+								if (found.Location != null)
+									return found;
+							}
+						}
 
-				case BuildingType.Building:
-					return FindPos(baseCenter, baseCenter, baseBuilder.Info.MinBaseRadius,
-						distanceToBaseIsImportant ? baseBuilder.Info.MaxBaseRadius : world.Map.Grid.MaximumTileSearchRange);
+						// Try and find a free spot somewhere else in the base
+						var fallback = FindPos(baseCenter, baseCenter, baseBuilder.Info.MinBaseRadius, baseBuilder.Info.MaxBaseRadius);
+						if (fallback.Location != null)
+							return fallback;
+						break;
+
+					case BuildingType.Building:
+						var building = FindPos(baseCenter, baseCenter, baseBuilder.Info.MinBaseRadius,
+							distanceToBaseIsImportant ? baseBuilder.Info.MaxBaseRadius : world.Map.Grid.MaximumTileSearchRange);
+						if (building.Location != null)
+							return building;
+						break;
+				}
 			}
 
 			// Can't find a build location

OpenRA.Mods.Common/Traits/BotModules/McvManagerBotModule.cs

@@ -44,6 +44,18 @@ public class McvManagerBotModuleInfo : ConditionalTraitInfo
 		[Desc("Should deployment of additional MCVs be restricted to MaxBaseRadius if explicit deploy locations are missing or occupied?")]
 		public readonly bool RestrictMCVDeploymentFallbackToBase = true;
 
+		[Desc("Cash threshold to trigger expansion (building a new MCV).")]
+		public readonly int ExpansionCashThreshold = 1000;
+
+		[Desc("Maximum number of bases (construction yards) allowed.")]
+		public readonly int MaxBaseCount = 2;
+
+		[Desc("Minimum distance from existing bases for a new expansion.")]
+		public readonly int MinimumExpansionDistance = 30;
+
+		[Desc("Maximum distance from existing bases for a new expansion.")]
+		public readonly int MaximumExpansionDistance = 50;
+
 		public override object Create(ActorInitializer init) { return new McvManagerBotModule(init.Self, this); }
 	}
 
@@ -66,6 +78,9 @@ public CPos GetRandomBaseCenter()
 
 		IBotPositionsUpdated[] notifyPositionsUpdated;
 		IBotRequestUnitProduction[] requestUnitProduction;
+		PlayerResources playerResources;
+		IResourceLayer resourceLayer;
+		TechTree techTree;
 
 		CPos initialBaseCenter;
 		int scanInterval;
@@ -85,6 +100,9 @@ protected override void Created(Actor self)
 		{
 			notifyPositionsUpdated = self.Owner.PlayerActor.TraitsImplementing<IBotPositionsUpdated>().ToArray();
 			requestUnitProduction = self.Owner.PlayerActor.TraitsImplementing<IBotRequestUnitProduction>().ToArray();
+			playerResources = self.Owner.PlayerActor.Trait<PlayerResources>();
+			resourceLayer = self.World.WorldActor.TraitOrDefault<IResourceLayer>();
+			techTree = self.Owner.PlayerActor.TraitOrDefault<TechTree>();
 		}
 
 		protected override void TraitEnabled(Actor self)
@@ -131,9 +149,36 @@ bool ShouldBuildMCV()
 			if (!allowedToBuildMCV)
 				return false;
 
-			// Build MCV if we don't have the desired number of construction yards, unless we have no factory (can't build it).
-			return AIUtils.CountActorByCommonName(constructionYards) < Info.MinimumConstructionYardCount &&
-				AIUtils.CountActorByCommonName(mcvFactories) > 0;
+			var constructionYardCount = AIUtils.CountActorByCommonName(constructionYards);
+
+			// Recovery Mode: Build MCV if we don't have any construction yards (and we have a factory to build it).
+			if (constructionYardCount < Info.MinimumConstructionYardCount && AIUtils.CountActorByCommonName(mcvFactories) > 0)
+				return true;
+
+			// Expansion Mode: Build MCV if we have excess cash and haven't reached max base count.
+			var activeMcvs = AIUtils.CountActorByCommonName(mcvs);
+
+			// Count MCVs currently in production queue (to avoid double ordering)
+			var mcvsInProduction = world.ActorsWithTrait<ProductionQueue>()
+				.Where(a => a.Actor.Owner == player)
+				.SelectMany(a => a.Trait.AllQueued())
+				.Count(i => Info.McvTypes.Contains(i.Item));
+
+			if (constructionYardCount + activeMcvs + mcvsInProduction < Info.MaxBaseCount)
+			{
+				// Check if we can build any MCV (prerequisites met)
+				foreach (var mcvType in Info.McvTypes)
+				{
+					if (!world.Map.Rules.Actors.TryGetValue(mcvType, out var actorInfo))
+						continue;
+
+					var buildable = actorInfo.TraitInfoOrDefault<BuildableInfo>();
+					if (buildable != null && techTree != null && techTree.HasPrerequisites(buildable.Prerequisites))
+						return true;
+				}
+			}
+
+			return false;
 		}
 
 		void DeployMcvs(IBot bot, bool chooseLocation)
@@ -151,12 +196,16 @@ void DeployMcv(IBot bot, Actor mcv, bool move)
 			if (move)
 			{
 				// If we lack a base, we need to make sure we don't restrict deployment of the MCV to the base!
+				var baseCount = AIUtils.CountActorByCommonName(constructionYards);
 				var restrictToBase =
 					Info.RestrictMCVDeploymentFallbackToBase &&
-					AIUtils.CountActorByCommonName(constructionYards) > 0;
+					baseCount > 0;
+
+				// If we are expanding (have at least one base), we should look for a spot further away
+				var isExpansion = baseCount > 0;
 
 				var transformsInfo = mcv.Info.TraitInfo<TransformsInfo>();
-				var desiredLocation = ChooseMcvDeployLocation(transformsInfo.IntoActor, transformsInfo.Offset, restrictToBase);
+				var desiredLocation = ChooseMcvDeployLocation(transformsInfo.IntoActor, transformsInfo.Offset, restrictToBase, isExpansion);
 				if (desiredLocation == null)
 					return;
 
@@ -175,7 +224,7 @@ void DeployMcv(IBot bot, Actor mcv, bool move)
 			bot.QueueOrder(new Order("DeployTransform", mcv, true));
 		}
 
-		CPos? ChooseMcvDeployLocation(string actorType, CVec offset, bool distanceToBaseIsImportant)
+		CPos? ChooseMcvDeployLocation(string actorType, CVec offset, bool distanceToBaseIsImportant, bool isExpansion)
 		{
 			var actorInfo = world.Map.Rules.Actors[actorType];
 			var bi = actorInfo.TraitInfoOrDefault<BuildingInfo>();
@@ -201,9 +250,36 @@ void DeployMcv(IBot bot, Actor mcv, bool move)
 			}
 
 			var baseCenter = GetRandomBaseCenter();
+			var targetCenter = baseCenter;
+			var minRange = Info.MinBaseRadius;
+			var maxRange = distanceToBaseIsImportant ? Info.MaxBaseRadius : world.Map.Grid.MaximumTileSearchRange;
+
+			if (isExpansion && resourceLayer != null)
+			{
+				// Find a resource patch that is far enough from existing bases
+				var existingBases = constructionYards.Actors.Select(a => a.Location).ToList();
+				var maxSearchRadius = System.Math.Min(Info.MaximumExpansionDistance, world.Map.Grid.MaximumTileSearchRange);
+				var minSearchRadius = System.Math.Min(Info.MinimumExpansionDistance, maxSearchRadius);
+
+				var potentialResourceTiles = world.Map.FindTilesInAnnulus(baseCenter, minSearchRadius, maxSearchRadius)
+					.Where(c => resourceLayer.GetResource(c).Type != null)
+					.Shuffle(world.LocalRandom)
+					.Take(20);
+
+				foreach (var tile in potentialResourceTiles)
+				{
+					// Ensure this tile is far from ALL existing bases
+					if (existingBases.All(baseLoc => (tile - baseLoc).LengthSquared >= Info.MinimumExpansionDistance * Info.MinimumExpansionDistance))
+					{
+						targetCenter = tile;
+						minRange = 2; // Close to resources
+						maxRange = 10;
+						break;
+					}
+				}
+			}
 
-			return FindPos(baseCenter, baseCenter, Info.MinBaseRadius,
-				distanceToBaseIsImportant ? Info.MaxBaseRadius : world.Map.Grid.MaximumTileSearchRange);
+			return FindPos(targetCenter, targetCenter, minRange, maxRange);
 		}
 
 		List<MiniYamlNode> IGameSaveTraitData.IssueTraitData(Actor self)