Add 'antilight' overlay on corner turfs to make them look good

code/game/turfs/simulated/floor_types.dm

@@ -83,6 +83,16 @@
 	var/turf/under_turf //Underlay override turf path.
 	var/join_flags = 0 //Bitstring to represent adjacency of joining walls
 	var/join_group = "shuttle" //A tag for what other walls to join with. Null if you don't want them to.
+	var/static/list/antilight_cache
+
+/turf/simulated/shuttle/New()
+	..()
+	if(!antilight_cache)
+		antilight_cache = list()
+		for(var/diag in cornerdirs)
+			var/image/I = image(LIGHTING_ICON, null, icon_state = "diagonals", layer = 10, dir = diag)
+			I.plane = PLANE_LIGHTING
+			antilight_cache["[diag]"] = I
 
 /turf/simulated/shuttle/Destroy()
 	landed_holder = null
@@ -143,13 +153,20 @@
 		under_ma = new(under)
 
 	if(under_ma)
-		if(ispath(under,/turf/space)) //Scramble space turfs
+		if(ispath(under,/turf/space)) //Space gets weird treatment
 			under_ma.icon_state = "white"
 			under_ma.plane = SPACE_PLANE
 		us.underlays = list(under_ma)
 
 	appearance = us
 
+	//Dynamic lighting dissolver
+	var/turf/T = get_step(src, turn(join_flags,180))
+	if(!T || !T.dynamic_lighting || !get_area(T).dynamic_lighting)
+		add_overlay(antilight_cache["[join_flags]"], TRUE)
+	else
+		cut_overlay(antilight_cache["[join_flags]"], TRUE)
+
 	return under
 
 /turf/simulated/shuttle/floor