allow AppearsOnRadar to use Location rather than OccupiedCells, for things that don't occupy any cells

OpenRA.Mods.RA/AppearsOnRadar.cs

@@ -15,17 +15,30 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.RA
 {
-	public class AppearsOnRadarInfo : TraitInfo<AppearsOnRadar> {}
+	public class AppearsOnRadarInfo : TraitInfo<AppearsOnRadar>
+	{
+		public readonly bool UseLocation = false;
+	}
+
 	public class AppearsOnRadar : IRadarSignature
 	{
+		AppearsOnRadarInfo info;
 		IOccupySpace Space;
 
 		public IEnumerable<int2> RadarSignatureCells(Actor self)
+		{
+			if (info == null)
+				info = self.Info.Traits.Get<AppearsOnRadarInfo>();
+
+			if (info.UseLocation)
+				return new int2[] { self.Location };
+			else
 			{
 				if (Space == null)
 					Space = self.Trait<IOccupySpace>();
 				return Space.OccupiedCells();
 			}
+		}
 		
 		public Color RadarSignatureColor(Actor self)
 		{

mods/cnc/rules/defaults.yaml

@@ -58,6 +58,7 @@
 
 ^Helicopter:
 	AppearsOnRadar:
+		UseLocation: yes
 	Targetable:
 		TargetTypes: Air
 	Selectable:
@@ -135,6 +136,7 @@
 
 ^Plane:
 	AppearsOnRadar:
+		UseLocation: yes
 	Selectable:
 		Voice: GenericVoice
 	Targetable:

mods/ra/rules/defaults.yaml

@@ -104,6 +104,7 @@
 
 ^Plane:
 	AppearsOnRadar:
+		UseLocation: yes
 	Selectable:
 		Voice: GenericVoice
 	TargetableAircraft: