bdebug=true will show appropriate influence for current building

OpenRa.Game/MainWindow.cs

@@ -50,6 +50,7 @@ namespace OpenRa.Game
 			SheetBuilder.Initialize(renderer);
 
 			UiOverlay.ShowUnitDebug = settings.GetValue("udebug", false);
+			UiOverlay.ShowBuildDebug = settings.GetValue("bdebug", false);
 			WorldRenderer.ShowUnitPaths = settings.GetValue("pathdebug", false);
 			Game.Replay = settings.GetValue("replay", "");
 

OpenRa.Game/Traits/Activities/Harvest.cs

@@ -41,11 +41,7 @@ namespace OpenRa.Game.Traits.Activities
 		void PlanReturnToBase(Actor self, Mobile mobile)	
 		{
 			/* find a proc */
-			var proc = Game.world.Actors.Where(
+			var proc = ChooseReturnLocation(self);
-				a => a.Owner == self.Owner &&
-					 a.traits.Contains<AcceptsOre>())
-					 .FirstOrDefault();		/* todo: *closest* proc, maybe? */
-
 			if (proc == null)
 			{
 				Cancel(self, mobile);		/* is this a sane way to cancel? */
@@ -59,6 +55,18 @@ namespace OpenRa.Game.Traits.Activities
 			mobile.InternalSetActivity(NextActivity);
 		}
 
+		static Actor ChooseReturnLocation(Actor self)
+		{
+			/* todo: compute paths to possible procs, taking into account enemy presence */
+			/* currently, we're good at choosing close, inaccessible procs */
+
+			return Game.world.Actors.Where(
+				a => a.Owner == self.Owner &&
+					 a.traits.Contains<AcceptsOre>())
+					 .OrderBy(p => (p.Location - self.Location).LengthSquared)
+					 .FirstOrDefault();
+		}
+
 		void PlanMoreHarvesting(Actor self, Mobile mobile)
 		{
 			/* find a nearby patch */

OpenRa.Game/UiOverlay.cs

@@ -12,6 +12,7 @@ namespace OpenRa.Game
 		Sprite buildOk, buildBlocked, unitDebug;
 
 		public static bool ShowUnitDebug = false;
+		public static bool ShowBuildDebug = false;
 
 		public UiOverlay(SpriteRenderer spriteRenderer)
 		{
@@ -49,6 +50,14 @@ namespace OpenRa.Game
 			var bi = (UnitInfo.BuildingInfo)Rules.UnitInfo[placeBuilding.Name];
 			
 			var maxDistance = bi.Adjacent + 2;	/* real-ra is weird. this is 1 GAP. */
+
+			if (ShowBuildDebug)
+				for (var j = 0; j < 128; j++)
+					for (var i = 0; i < 128; i++)
+						if (Game.GetDistanceToBase(new int2(i, j), Game.LocalPlayer) < maxDistance)
+							if (Game.IsCellBuildable(new int2(i, j), bi.WaterBound ? UnitMovementType.Float : UnitMovementType.Wheel))
+								spriteRenderer.DrawSprite(unitDebug, Game.CellSize * new float2(i, j), 0);
+			
 			var tooFarFromBase = !Footprint.Tiles(bi, position).Any(
 				t => Game.GetDistanceToBase(t, Game.LocalPlayer) < maxDistance);