Added another mode for smoothing (smooth with all subtypes).

code/__HELPERS/icon_smoothing.dm

@@ -1,10 +1,26 @@
-/atom/var/smooth = 0
+//Redefinitions of the diagonal directions so they can be stored in one var without conflicts
+#define NORTH_EAST	16
+#define NORTH_WEST	32
+#define SOUTH_EAST	64
+#define SOUTH_WEST	128
+
+#define SMOOTH_FALSE	0 //not smooth
+#define SMOOTH_TRUE		1 //smooths with exact specified types or just itself
+#define SMOOTH_MORE		2 //smooths with all subtypes of specified types or just itself
+
+/atom/var/smooth = SMOOTH_FALSE
 /atom/var/top_left_corner
 /atom/var/top_right_corner
 /atom/var/bottom_left_corner
 /atom/var/bottom_right_corner
 /atom/var/can_be_unanchored = 0
-/atom/var/list/canSmoothWith=list() // TYPE PATHS I CAN SMOOTH WITH~~~~~
+/atom/var/list/canSmoothWith = null // TYPE PATHS I CAN SMOOTH WITH~~~~~ If this is null and atom is smooth, it smooths only with itself
+
+/atom/proc/clear_smooth_overlays()
+	overlays -= top_left_corner
+	overlays -= top_right_corner
+	overlays -= bottom_right_corner
+	overlays -= bottom_left_corner
 
 //generic (by snowflake) tile smoothing code; smooth your icons with this!
 /*
@@ -16,12 +32,6 @@
 	Each atom has its own icon file with all the possible corner states. See 'smooth_wall.dmi' for a template.
 */
 
-//Redefinitions of the diagonal directions so they can be stored in one var without conflicts
-#define NORTH_EAST	16
-#define NORTH_WEST	32
-#define SOUTH_EAST	64
-#define SOUTH_WEST	128
-
 /proc/calculate_adjacencies(atom/A)
 	if(!A.loc)
 		return 0
@@ -54,7 +64,7 @@
 		if(A && A.smooth)
 			var/adjacencies = calculate_adjacencies(A)
 
-			clear_overlays(A)
+			A.clear_smooth_overlays()
 
 			A.top_left_corner = make_nw_corner(adjacencies)
 			A.top_right_corner = make_ne_corner(adjacencies)
@@ -78,8 +88,6 @@
 			sdir = "n"
 		else if(adjacencies & WEST)
 			sdir = "w"
-		else
-			sdir = "i"
 	return "1-[sdir]"
 
 /proc/make_ne_corner(adjacencies)
@@ -94,8 +102,6 @@
 			sdir = "n"
 		else if(adjacencies & EAST)
 			sdir = "e"
-		else
-			sdir = "i"
 	return "2-[sdir]"
 
 /proc/make_sw_corner(adjacencies)
@@ -110,8 +116,6 @@
 			sdir = "s"
 		else if(adjacencies & WEST)
 			sdir = "w"
-		else
-			sdir = "i"
 	return "3-[sdir]"
 
 /proc/make_se_corner(adjacencies)
@@ -127,8 +131,6 @@
 		else
 			if(adjacencies & EAST)
 				sdir = "e"
-			else
-				sdir = "i"
 	return "4-[sdir]"
 
 /proc/smooth_icon_neighbors(atom/A)
@@ -153,14 +155,21 @@
 	var/turf/target_turf = locate(source.x + x_offset, source.y + y_offset, source.z)
 	if(source.canSmoothWith)
 		var/atom/A
-		for(var/a_type in source.canSmoothWith)
-			if(ispath(a_type, /turf))
-				if(a_type == target_turf.type)
+		if(source.smooth == SMOOTH_MORE)
+			for(var/a_type in source.canSmoothWith)
+				if( istype(target_turf, a_type) )
 					return target_turf
-			else
 				A = locate(a_type) in target_turf
-				if(A && A.type == a_type)
+				if(A)
 					return A
+			return null
+
+		for(var/a_type in source.canSmoothWith)
+			if(a_type == target_turf.type)
+				return target_turf
+			A = locate(a_type) in target_turf
+			if(A && A.type == a_type)
+				return A
 		return null
 	else
 		if(isturf(source))
@@ -168,12 +177,6 @@
 		var/atom/A = locate(source.type) in target_turf
 		return A && A.type == source.type ? A : null
 
-/proc/clear_overlays(atom/A)
-	A.overlays -= A.top_left_corner
-	A.overlays -= A.top_right_corner
-	A.overlays -= A.bottom_right_corner
-	A.overlays -= A.bottom_left_corner
-
 /proc/transform_dir(direction)
 	switch(direction)
 		if(NORTH,SOUTH,EAST,WEST)

code/game/objects/effects/aliens.dm

@@ -29,7 +29,7 @@
 	canSmoothWith = list(/obj/structure/alien/resin)
 	var/health = 200
 	var/resintype = null
-	smooth = 1
+	smooth = SMOOTH_TRUE
 
 
 /obj/structure/alien/resin/New(location)

code/game/objects/structures/false_walls.dm

@@ -19,7 +19,7 @@
 	/obj/structure/falsewall/reinforced,  // WHY DO WE SMOOTH WITH FALSE R-WALLS WHEN WE DON'T SMOOTH WITH REAL R-WALLS.
 	/turf/simulated/wall/rust,
 	/turf/simulated/wall/r_wall/rust)
-	smooth = 1
+	smooth = SMOOTH_TRUE
 	can_be_unanchored = 0
 
 /obj/structure/falsewall/attack_hand(mob/user)
@@ -49,15 +49,15 @@
 
 /obj/structure/falsewall/proc/do_the_flick()
 	if(density)
-		smooth = 0
-		clear_overlays(src)
+		smooth = SMOOTH_FALSE
+		clear_smooth_overlays()
 		icon_state = "fwall_opening"
 	else
 		icon_state = "fwall_closing"
 
 /obj/structure/falsewall/update_icon()//Calling icon_update will refresh the smoothwalls if it's closed, otherwise it will make sure the icon is correct if it's open
 	if(density)
-		smooth = 1
+		smooth = SMOOTH_TRUE
 		smooth_icon(src)
 		icon_state = ""
 	else

code/game/objects/structures/lattice.dm

@@ -8,18 +8,10 @@
 	layer = 2.3 //under pipes
 	var/obj/item/stack/rods/stored
 	canSmoothWith = list(/obj/structure/lattice,
-	/obj/structure/lattice/catwalk,
-	/turf/simulated/floor/plating,
-	/turf/simulated/floor/plating/airless,
+	/turf/simulated/floor,
 	/turf/simulated/wall,
-	/turf/simulated/wall/r_wall,
-	/turf/simulated/floor/plasteel,
-	/turf/simulated/floor/plasteel/airless,
-	/obj/structure/falsewall,
-	/obj/structure/falsewall/reinforced,
-	/turf/simulated/wall/rust,
-	/turf/simulated/wall/r_wall/rust)
-	smooth = 1
+	/obj/structure/falsewall)
+	smooth = SMOOTH_MORE
 	//	flags = CONDUCT
 
 /obj/structure/lattice/New()
@@ -75,6 +67,7 @@
 	desc = "A catwalk for easier EVA manuevering and cable placement."
 	icon = 'icons/obj/smooth_structures/catwalk.dmi'
 	icon_state = "catwalk"
+	smooth = SMOOTH_TRUE
 	canSmoothWith = null
 
 /obj/structure/lattice/catwalk/Move()

code/game/objects/structures/stool_bed_chair_nest/alien_nests.dm

@@ -6,7 +6,7 @@
 	icon = 'icons/obj/smooth_structures/alien/nest.dmi'
 	icon_state = "nest"
 	var/health = 100
-	smooth = 1
+	smooth = SMOOTH_TRUE
 	can_be_unanchored = 0
 	canSmoothWith = null
 	var/image/nest_overlay

code/game/objects/structures/tables_racks.dm

@@ -28,7 +28,7 @@
 	var/buildstackamount = 1
 	var/framestackamount = 2
 	var/mob/tableclimber
-	smooth = 1
+	smooth = SMOOTH_TRUE
 	canSmoothWith = list(/obj/structure/table, /obj/structure/table/reinforced)
 
 /obj/structure/table/New()

code/game/objects/structures/window.dm

@@ -441,7 +441,7 @@
 	dir = 5
 	maxhealth = 50
 	fulltile = 1
-	smooth = 1
+	smooth = SMOOTH_TRUE
 	canSmoothWith = list(/obj/structure/window/fulltile, /obj/structure/window/reinforced/fulltile, /obj/structure/window/reinforced/tinted/fulltile)
 
 /obj/structure/window/reinforced/fulltile
@@ -450,7 +450,7 @@
 	dir = 5
 	maxhealth = 100
 	fulltile = 1
-	smooth = 1
+	smooth = SMOOTH_TRUE
 	canSmoothWith = list(/obj/structure/window/fulltile, /obj/structure/window/reinforced/fulltile, /obj/structure/window/reinforced/tinted/fulltile)
 
 /obj/structure/window/reinforced/tinted/fulltile
@@ -458,7 +458,7 @@
 	icon_state = "tinted_window"
 	dir = 5
 	fulltile = 1
-	smooth = 1
+	smooth = SMOOTH_TRUE
 	canSmoothWith = list(/obj/structure/window/fulltile, /obj/structure/window/reinforced/fulltile, /obj/structure/window/reinforced/tinted/fulltile)
 
 /obj/structure/window/shuttle
@@ -471,6 +471,6 @@
 	wtype = "shuttle"
 	fulltile = 1
 	reinf = 1
-	smooth = 1
+	smooth = SMOOTH_TRUE
 	canSmoothWith = null
 	explosion_block = 1

code/game/turfs/simulated/floor/fancy_floor.dm

@@ -47,7 +47,7 @@
 	icon_state = "carpet"
 	floor_tile = /obj/item/stack/tile/carpet
 	broken_states = list("damaged")
-	smooth = 1
+	smooth = SMOOTH_TRUE
 	canSmoothWith = null
 
 /turf/simulated/floor/carpet/New()

code/game/turfs/simulated/walls.dm

@@ -25,7 +25,7 @@
 	/obj/structure/falsewall/reinforced,
 	/turf/simulated/wall/rust,
 	/turf/simulated/wall/r_wall/rust)
-	smooth = 1
+	smooth = SMOOTH_TRUE
 
 /turf/simulated/wall/New()
 	..()

code/game/turfs/simulated/walls_mineral.dm

@@ -4,8 +4,8 @@
 	icon_state = ""
 	var/last_event = 0
 	var/active = null
-	smooth = 1
 	canSmoothWith = null
+	smooth = SMOOTH_TRUE
 
 /turf/simulated/wall/mineral/New()
 	sheet_type = text2path("/obj/item/stack/sheet/mineral/[mineral]")

code/game/turfs/simulated/walls_misc.dm

@@ -45,7 +45,7 @@
 	icon = 'icons/turf/shuttle.dmi'
 	icon_state = "wall1"
 	walltype = "shuttle"
-	smooth = 0
+	smooth = SMOOTH_FALSE
 
 //sub-type to be used for interior shuttle walls
 //won't get an underlay of the destination turf on shuttle move

code/game/turfs/simulated/walls_reinforced.dm

@@ -215,10 +215,10 @@
 /turf/simulated/wall/r_wall/proc/update_icon()
 	if(d_state)
 		icon_state = "r_wall-[d_state]"
-		smooth = 0
-		clear_overlays(src)
+		smooth = SMOOTH_FALSE
+		clear_smooth_overlays()
 	else
-		smooth = 1
+		smooth = SMOOTH_TRUE
 		icon_state = ""
 
 /turf/simulated/wall/r_wall/singularity_pull(S, current_size)

code/game/turfs/turf.dm

@@ -317,8 +317,7 @@
 /turf/indestructible/riveted/uranium
 	icon = 'icons/turf/walls/uranium_wall.dmi'
 	icon_state = "uranium"
-	smooth = 1
-	canSmoothWith = null
+	smooth = SMOOTH_TRUE
 
 /turf/indestructible/abductor
 	icon_state = "alien1"