AI prefers resources near to a refinery, rather than the idle harvester.

When HarvesterBotModule is ordering idle harvesters to nearby resources, it previously scanned from the harvester's current location. Instead, it now scans from the location of the nearest refinery. As the harvester will likely make many runs between the resource and the refinery, it is better to choose a location near the refinery. This will minimise overall distance travelled to harvest the resource patch.

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

@@ -50,6 +50,7 @@ namespace OpenRA.Mods.Common.Traits
 		{
 			public readonly Actor Actor;
 			public readonly Harvester Harvester;
+			public readonly DockClientManager DockClientManager;
 			public readonly Parachutable Parachutable;
 			public readonly Mobile Mobile;
 			public int NoResourcesCooldown { get; set; }
@@ -58,6 +59,7 @@ namespace OpenRA.Mods.Common.Traits
 			{
 				Actor = actor;
 				Harvester = actor.Trait<Harvester>();
+				DockClientManager = actor.Trait<DockClientManager>();
 				Parachutable = actor.TraitOrDefault<Parachutable>();
 				Mobile = actor.TraitOrDefault<Mobile>();
 			}
@@ -203,6 +205,9 @@ namespace OpenRA.Mods.Common.Traits
 
 		Target FindNextResource(Actor actor, HarvesterTraitWrapper harv)
 		{
+			// Prefer resource nearby to the nearest drop off point, otherwise scan from the current location.
+			var scanFromActor = harv.DockClientManager.ClosestDock(null, ignoreOccupancy: true)?.Actor ?? actor;
+
 			var targets = resourceTypesByCell
 				.Where(kvp =>
 					harv.Harvester.Info.Resources.Contains(kvp.Value) &&
@@ -238,7 +243,7 @@ namespace OpenRA.Mods.Common.Traits
 			}
 
 			var path = harv.Mobile.PathFinder.FindPathToTargetCells(
-				actor, actor.Location, targets, BlockedByActor.Stationary,
+				actor, scanFromActor.Location, targets, BlockedByActor.Stationary,
 				loc =>
 				{
 					// Avoid areas with enemies.