Respects Windows and our Inability to Pass Them

Blood that would splatter onto windows is now pixel-shifted and renders
above them so you can A: Clean it with ease and B: See it in all its
gorey glory.

I had to get creative with how I detected structures blocking blood
splatter.

Janiborgs riding, sprayers spraying and cleaner grenades foaming over
adjacent tiles won't clean off wall/windowblood. You have to use soap
and click on the blood.

code/modules/reagents/chemistry/reagents/water.dm

@@ -132,18 +132,27 @@
 	taste_message = "floor cleaner"
 
 /datum/reagent/space_cleaner/reaction_obj(obj/O, volume)
-	if(istype(O, /obj/effect/decal/cleanable))
-		qdel(O)
+	if(is_cleanable(O))
+		var/obj/effect/decal/cleanable/blood/B = O
+		if(!(istype(B) && B.off_floor))
+			qdel(O)
 	else
-		O.color = initial(O.color)
+		if(!istype(O, /atom/movable/lighting_overlay))
+			O.color = initial(O.color)
 		O.clean_blood()
 
 /datum/reagent/space_cleaner/reaction_turf(turf/T, volume)
 	if(volume >= 1)
-		T.color = initial(T.color)
-		T.clean_blood()
+		var/floor_only = TRUE
 		for(var/obj/effect/decal/cleanable/C in src)
-			qdel(C)
+			var/obj/effect/decal/cleanable/blood/B = C
+			if(istype(B) && B.off_floor)
+				floor_only = FALSE
+			else
+				qdel(C)
+		T.color = initial(T.color)
+		if(floor_only)
+			T.clean_blood()
 
 		for(var/mob/living/carbon/slime/M in T)
 			M.adjustToxLoss(rand(5,10))