helpers

code/game/area/Space_Station_13_areas.dm

@@ -43,6 +43,7 @@ NOTE: there are two lists of areas in the end of this file: centcom and station
 	outdoors = TRUE
 	ambientsounds = SPACE
 	blob_allowed = FALSE //Eating up space doesn't count for victory as a blob.
+	considered_hull_exterior = TRUE
 
 /area/space/nearstation
 	icon_state = "space_near"
@@ -1592,4 +1593,4 @@ NOTE: there are two lists of areas in the end of this file: centcom and station
 	valid_territory = FALSE
 	outdoors = TRUE
 	ambientsounds = SPACE
-	blob_allowed = FALSE //While part of the station, what good will it do you?
+	blob_allowed = FALSE //While part of the station, what good will it do you?

code/game/area/areas.dm

@@ -34,6 +34,9 @@
 	/// If megafauna can be spawned by natural random generation
 	var/megafauna_spawn_allowed = FALSE
 
+	/// Considered space for hull shielding
+	var/considered_hull_exterior = FALSE
+
 	var/fire = null
 	var/atmos = TRUE
 	var/atmosalm = FALSE

code/modules/shielding/helpers.dm

@@ -0,0 +1,85 @@
+//////// HELPER FILE FOR SHIELDING /////////
+
+// HULL SHIELD GENERATION HELPERS
+/**
+  * Gets hull exterior adjacent tiles of a certain area
+  * Area method.
+  * EXPENSIVE.
+  * If the area itself is already considered exterior, it'll find all tiles inside it that's next to an interior area.
+  */
+/proc/hull_shielding_get_tiles_around_area(area/instance, check_tick = FALSE)
+	var/list/cache = list()
+	var/area/A
+	if(instance.considered_hull_exterior)
+		for(var/turf/potential in instance)
+			for(var/turf/looking in orange(1, potential))
+				A = looking.loc
+				if(!A.considered_hull_exterior)
+					cache[potential] = TRUE			// we're the exterior area, grab the one that's reaching out
+			if(check_tick)
+				CHECK_TICK
+	else
+		for(var/turf/potential in instance)
+			for(var/turf/looking in orange(1, potential))
+				A = looking.loc
+				if(A.considered_hull_exterior)
+					cache[looking] = TRUE			// we're not the exterior area, grab the one that's being reached to
+			if(check_tick)
+				CHECK_TICK
+	. = list()
+	for(var/i in cache)
+		. += i			// strip assoc value
+
+/**
+  * Gets hull adjacent exterior tiles of an entire zlevel
+  * EXPENSIVE.
+  * Gets the tiles in the exterior area touching to a non-exterior area
+  */
+/proc/hull_shielding_get_tiles_in_z(zlevel, check_tick = FALSE, recurse = FALSE, list/outlist = list(), list/scanned_zlevels = list())
+	. = outlist
+	if(zlevel in scanned_zlevels)
+		return
+	scanned_zlevels |= zlevel
+	if(recurse)
+		var/up = SSmapping.level_trait(zlevel, ZTRAIT_UP)
+		var/down = SSmapping.level_trait(zlevel, ZTRAIT_DOWN)
+		if(isnum(up) && (up != 0))
+			hull_shielding_get_tiles_in_z(up, check_tick, recurse, outlist, scanned_zlevels)
+		if(isnum(down) && (down != 0))
+			hull_shielding_get_tiles_in_z(down, check_tick, recurse, outlist, scanned_zlevels)
+	// sigh. why.
+	var/turf/potential
+	var/area/p_area
+	var/area/l_area
+	for(var/x in 1 to world.maxx)
+		for(var/y in 1 to world.maxy)
+			if(check_tick)
+				CHECK_TICK
+			potential = locate(x, y)
+			p_area = potential.loc
+			if(!p_area.considered_hull_exterior)
+				continue
+			for(var/turf/looking in orange(1, potential))
+				l_area = looking.loc
+				if(!l_area.considered_hull_exterior)
+					outlist += potential
+
+/proc/debug1(area/A)
+	for(var/turf/T in hull_shielding_get_tiles_around_area(A, FALSE))
+		T.maptext = "Found"
+		T.plane = 50
+		T.layer = 50
+		spawn(100)
+			T.maptext = null
+			T.plane = initial(T.plane)
+			T.layer = initial(T.layer)
+
+/proc/debug2(z)
+	for(var/turf/T in hull_shielding_get_tiles_in_z(z, FALSE, TRUE))
+		T.maptext = "Found"
+		T.plane = 50
+		T.layer = 50
+		spawn(100)
+			T.maptext = null
+			T.plane = initial(T.plane)
+			T.layer = initial(T.layer)

tgstation.dme

@@ -3287,6 +3287,7 @@
 #include "code\modules\ruins\spaceruin_code\whiteshipruin_box.dm"
 #include "code\modules\security_levels\keycard_authentication.dm"
 #include "code\modules\security_levels\security_levels.dm"
+#include "code\modules\shielding\helpers.dm"
 #include "code\modules\shuttle\arrivals.dm"
 #include "code\modules\shuttle\assault_pod.dm"
 #include "code\modules\shuttle\computer.dm"