[MIRROR] Multi-Z Support for Lazy Templates | Cleans up some turf flag misuse [MDB IGNORE] (#23794)

* Multi-Z Support for Lazy Templates | Cleans up some turf flag misuse

* Update hilbertshotel.dm

* Modular proc ref

---------

Co-authored-by: Zephyr <12817816+ZephyrTFA@users.noreply.github.com>
Co-authored-by: Bloop <13398309+vinylspiders@users.noreply.github.com>

code/modules/mapping/map_template.dm

@@ -133,7 +133,15 @@
 	var/y = round((world.maxy - height) * 0.5) + 1
 
 	var/datum/space_level/level = SSmapping.add_new_zlevel(name, secret ? ZTRAITS_AWAY_SECRET : ZTRAITS_AWAY, contain_turfs = FALSE)
-	var/datum/parsed_map/parsed = load_map(file(mappath), x, y, level.z_value, no_changeturf=(SSatoms.initialized == INITIALIZATION_INSSATOMS), placeOnTop=should_place_on_top, new_z = TRUE)
+	var/datum/parsed_map/parsed = load_map(
+		file(mappath),
+		x,
+		y,
+		level.z_value,
+		no_changeturf = (SSatoms.initialized == INITIALIZATION_INSSATOMS),
+		place_on_top = should_place_on_top,
+		new_z = TRUE,
+	)
 	var/list/bounds = parsed.bounds
 	if(!bounds)
 		return FALSE
@@ -177,7 +185,14 @@
 
 	UNSETEMPTY(turf_blacklist)
 	parsed.turf_blacklist = turf_blacklist
-	if(!parsed.load(T.x, T.y, T.z, cropMap=TRUE, no_changeturf=(SSatoms.initialized == INITIALIZATION_INSSATOMS), placeOnTop=should_place_on_top))
+	if(!parsed.load(
+		T.x,
+		T.y,
+		T.z,
+		crop_map = TRUE,
+		no_changeturf = (SSatoms.initialized == INITIALIZATION_INSSATOMS),
+		place_on_top = should_place_on_top,
+	))
 		return
 
 	var/list/bounds = parsed.bounds

code/modules/mapping/reader.dm

@@ -114,26 +114,72 @@
 	var/turfsSkipped = 0
 	#endif
 
+/datum/parsed_map/proc/copy()
+	// Avoids duped work just in case
+	build_cache()
+	var/datum/parsed_map/newfriend = new()
+	newfriend.original_path = original_path
+	newfriend.map_format = map_format
+	newfriend.key_len = key_len
+	newfriend.line_len = line_len
+	newfriend.grid_models = grid_models.Copy()
+	newfriend.gridSets = gridSets.Copy()
+	newfriend.modelCache = modelCache.Copy()
+	newfriend.parsed_bounds = parsed_bounds.Copy()
+	// Copy parsed bounds to reset to initial values
+	newfriend.bounds = parsed_bounds.Copy()
+	newfriend.turf_blacklist = turf_blacklist?.Copy()
+	return newfriend
+
 //text trimming (both directions) helper macro
 #define TRIM_TEXT(text) (trim_reduced(text))
 
-/// Shortcut function to parse a map and apply it to the world.
-///
-/// - `dmm_file`: A .dmm file to load (Required).
-/// - `x_offset`, `y_offset`, `z_offset`: Positions representign where to load the map (Optional).
-/// - `cropMap`: When true, the map will be cropped to fit the existing world dimensions (Optional).
-/// - `measureOnly`: When true, no changes will be made to the world (Optional).
-/// - `no_changeturf`: When true, [/turf/proc/AfterChange] won't be called on loaded turfs
-/// - `x_lower`, `x_upper`, `y_lower`, `y_upper`: Coordinates (relative to the map) to crop to (Optional).
-/// - `placeOnTop`: Whether to use [/turf/proc/PlaceOnTop] rather than [/turf/proc/ChangeTurf] (Optional).
-/proc/load_map(dmm_file as file, x_offset as num, y_offset as num, z_offset as num, cropMap as num, measureOnly as num, no_changeturf as num, x_lower = -INFINITY as num, x_upper = INFINITY as num, y_lower = -INFINITY as num, y_upper = INFINITY as num, placeOnTop = FALSE as num, new_z)
-	var/datum/parsed_map/parsed = new(dmm_file, x_lower, x_upper, y_lower, y_upper, measureOnly)
-	if(parsed.bounds && !measureOnly)
-		parsed.load(x_offset, y_offset, z_offset, cropMap, no_changeturf, x_lower, x_upper, y_lower, y_upper, placeOnTop, new_z = new_z)
-	return parsed
+/**
+ * Helper and recommened way to load a map file
+ * - dmm_file: The path to the map file
+ * - x_offset: The x offset to load the map at
+ * - y_offset: The y offset to load the map at
+ * - z_offset: The z offset to load the map at
+ * - crop_map: If true, the map will be cropped to the world bounds
+ * - measure_only: If true, the map will not be loaded, but the bounds will be calculated
+ * - no_changeturf: If true, the map will not call /turf/AfterChange
+ * - x_lower: The minimum x coordinate to load
+ * - x_upper: The maximum x coordinate to load
+ * - y_lower: The minimum y coordinate to load
+ * - y_upper: The maximum y coordinate to load
+ * - z_lower: The minimum z coordinate to load
+ * - z_upper: The maximum z coordinate to load
+ * - place_on_top: Whether to use /turf/proc/PlaceOnTop rather than /turf/proc/ChangeTurf
+ * - new_z: If true, a new z level will be created for the map
+ */
+/proc/load_map(
+	dmm_file,
+	x_offset = 0,
+	y_offset = 0,
+	z_offset = 0,
+	crop_map = FALSE,
+	measure_only = FALSE,
+	no_changeturf = FALSE,
+	x_lower = -INFINITY,
+	x_upper = INFINITY,
+	y_lower = -INFINITY,
+	y_upper = INFINITY,
+	z_lower = -INFINITY,
+	z_upper = INFINITY,
+	place_on_top = FALSE,
+	new_z = FALSE,
+)
+	if(!(dmm_file in GLOB.cached_maps))
+		GLOB.cached_maps[dmm_file] = new /datum/parsed_map(dmm_file)
+
+	var/datum/parsed_map/parsed_map = GLOB.cached_maps[dmm_file]
+	parsed_map = parsed_map.copy()
+	if(!measure_only && !isnull(parsed_map.bounds))
+		parsed_map.load(x_offset, y_offset, z_offset, crop_map, no_changeturf, x_lower, x_upper, y_lower, y_upper, z_lower, z_upper, place_on_top, new_z)
+	return parsed_map
 
 /// Parse a map, possibly cropping it.
-/datum/parsed_map/New(tfile, x_lower = -INFINITY, x_upper = INFINITY, y_lower = -INFINITY, y_upper=INFINITY, measureOnly=FALSE)
+/datum/parsed_map/New(tfile, x_lower = -INFINITY, x_upper = INFINITY, y_lower = -INFINITY, y_upper=INFINITY, z_lower = -INFINITY, z_upper=INFINITY, measureOnly=FALSE)
 	// This proc sleeps for like 6 seconds. why?
 	// Is it file accesses? if so, can those be done ahead of time, async to save on time here? I wonder.
 	// Love ya :)
@@ -184,20 +230,26 @@
 				CRASH("Coords before model definition in DMM")
 
 			var/curr_x = text2num(regexOutput[3])
-
 			if(curr_x < x_lower || curr_x > x_upper)
 				continue
 
+			var/curr_y = text2num(regexOutput[4])
+			if(curr_y < y_lower || curr_y > y_upper)
+				continue
+
+			var/curr_z = text2num(regexOutput[5])
+			if(curr_z < z_lower || curr_z > z_upper)
+				continue
+
 			var/datum/grid_set/gridSet = new
 
 			gridSet.xcrd = curr_x
-			//position of the currently processed square
-			gridSet.ycrd = text2num(regexOutput[4])
-			gridSet.zcrd = text2num(regexOutput[5])
+			gridSet.ycrd = curr_y
+			gridSet.zcrd = curr_z
 
 			bounds[MAP_MINX] = min(bounds[MAP_MINX], curr_x)
-			bounds[MAP_MINZ] = min(bounds[MAP_MINZ], gridSet.zcrd)
-			bounds[MAP_MAXZ] = max(bounds[MAP_MAXZ], gridSet.zcrd)
+			bounds[MAP_MINZ] = min(bounds[MAP_MINZ], curr_y)
+			bounds[MAP_MAXZ] = max(bounds[MAP_MAXZ], curr_z)
 
 			var/list/gridLines = splittext(regexOutput[6], "\n")
 			gridSet.gridLines = gridLines
@@ -238,16 +290,29 @@
 		bounds[MAP_MAXX] = clamp(bounds[MAP_MAXX], x_lower, x_upper)
 		bounds[MAP_MINY] = clamp(bounds[MAP_MINY], y_lower, y_upper)
 		bounds[MAP_MAXY] = clamp(bounds[MAP_MAXY], y_lower, y_upper)
+		bounds[MAP_MINZ] = clamp(bounds[MAP_MINZ], z_lower, z_upper)
+		bounds[MAP_MAXZ] = clamp(bounds[MAP_MAXZ], z_lower, z_upper)
 
 	parsed_bounds = src.bounds
 	src.key_len = key_len
 	src.line_len = line_len
 
-/// Load the parsed map into the world. See [/proc/load_map] for arguments.
-/datum/parsed_map/proc/load(x_offset, y_offset, z_offset, cropMap, no_changeturf, x_lower, x_upper, y_lower, y_upper, placeOnTop, whitelist = FALSE, new_z)
+/// Iterates over all grid sets and returns ones with z values within the given bounds. Inclusive
+/datum/parsed_map/proc/filter_grid_sets_based_on_z_bounds(lower_z, upper_z)
+	var/list/filtered_sets = list()
+	for(var/datum/grid_set/grid_set as anything in gridSets)
+		if(grid_set.zcrd < lower_z)
+			continue
+		if(grid_set.zcrd > upper_z)
+			continue
+		filtered_sets += grid_set
+	return filtered_sets
+
+/// Load the parsed map into the world. You probably want [/proc/load_map]. Keep the signature the same.
+/datum/parsed_map/proc/load(x_offset = 0, y_offset = 0, z_offset = 0, crop_map = FALSE, no_changeturf = FALSE, x_lower = -INFINITY, x_upper = INFINITY, y_lower = -INFINITY, y_upper = INFINITY, z_lower = -INFINITY, z_upper = INFINITY, place_on_top = FALSE, new_z = FALSE)
 	//How I wish for RAII
 	Master.StartLoadingMap()
-	. = _load_impl(x_offset, y_offset, z_offset, cropMap, no_changeturf, x_lower, x_upper, y_lower, y_upper, placeOnTop, new_z)
+	. = _load_impl(x_offset, y_offset, z_offset, crop_map, no_changeturf, x_lower, x_upper, y_lower, y_upper, z_lower, z_upper, place_on_top, new_z)
 	Master.StopLoadingMap()
 
 #define MAPLOADING_CHECK_TICK \
@@ -262,7 +327,7 @@
 	}
 
 // Do not call except via load() above.
-/datum/parsed_map/proc/_load_impl(x_offset = 1, y_offset = 1, z_offset = world.maxz + 1, cropMap = FALSE, no_changeturf = FALSE, x_lower = -INFINITY, x_upper = INFINITY, y_lower = -INFINITY, y_upper = INFINITY, placeOnTop = FALSE, new_z = FALSE)
+/datum/parsed_map/proc/_load_impl(x_offset, y_offset, z_offset, crop_map, no_changeturf, x_lower, x_upper, y_lower, y_upper, z_lower, z_upper, place_on_top, new_z)
 	PRIVATE_PROC(TRUE)
 	// Tell ss atoms that we're doing maploading
 	// We'll have to account for this in the following tick_checks so it doesn't overflow
@@ -275,9 +340,9 @@
 	var/sucessful = FALSE
 	switch(map_format)
 		if(MAP_TGM)
-			sucessful = _tgm_load(x_offset, y_offset, z_offset, cropMap, no_changeturf, x_lower, x_upper, y_lower, y_upper, placeOnTop, new_z)
+			sucessful = _tgm_load(x_offset, y_offset, z_offset, crop_map, no_changeturf, x_lower, x_upper, y_lower, y_upper, z_lower, z_upper, place_on_top, new_z)
 		else
-			sucessful = _dmm_load(x_offset, y_offset, z_offset, cropMap, no_changeturf, x_lower, x_upper, y_lower, y_upper, placeOnTop, new_z)
+			sucessful = _dmm_load(x_offset, y_offset, z_offset, crop_map, no_changeturf, x_lower, x_upper, y_lower, y_upper, z_lower, z_upper, place_on_top, new_z)
 
 	// And we are done lads, call it off
 	SSatoms.map_loader_stop(REF(src))
@@ -309,7 +374,7 @@
 // In the tgm format, each gridset contains 255 lines, each line representing one tile, with 255 total gridsets
 // In the dmm format, each gridset contains 255 lines, each line representing one row of tiles, containing 255 * line length characters, with one gridset per z
 // You can think of dmm as storing maps in rows, whereas tgm stores them in columns
-/datum/parsed_map/proc/_tgm_load(x_offset, y_offset, z_offset, cropMap, no_changeturf, x_lower, x_upper, y_lower, y_upper, placeOnTop, new_z)
+/datum/parsed_map/proc/_tgm_load(x_offset, y_offset, z_offset, crop_map, no_changeturf, x_lower, x_upper, y_lower, y_upper, z_lower, z_upper, place_on_top, new_z)
 	// setup
 	var/list/modelCache = build_cache(no_changeturf)
 	var/space_key = modelCache[SPACE_KEY]
@@ -330,12 +395,12 @@
 	var/relative_y = first_column.ycrd
 	var/highest_y = relative_y + y_relative_to_absolute
 
-	if(!cropMap && highest_y > world.maxy)
+	if(!crop_map && highest_y > world.maxy)
 		if(new_z)
 			// Need to avoid improperly loaded area/turf_contents
-			world.increaseMaxY(highest_y, max_zs_to_load = z_offset - 1)
+			world.increase_max_y(highest_y, map_load_z_cutoff = z_offset - 1)
 		else
-			world.increaseMaxY(highest_y)
+			world.increase_max_y(highest_y)
 		expanded_y = TRUE
 
 	// Skip Y coords that are above the smallest of the three params
@@ -345,7 +410,6 @@
 	var/y_starting_skip = relative_y - y_skip_above
 	highest_y -= y_starting_skip
 
-
 	// Y is the LOWEST it will ever be here, so we can easily set a threshold for how low to go
 	var/line_count = length(first_column.gridLines)
 	var/lowest_y = relative_y - (line_count - 1) // -1 because we decrement at the end of the loop, not the start
@@ -353,7 +417,7 @@
 
 	// X setup
 	var/x_delta_with = x_upper
-	if(cropMap)
+	if(crop_map)
 		// Take our smaller crop threshold yes?
 		x_delta_with = min(x_delta_with, world.maxx)
 
@@ -367,33 +431,51 @@
 		// If our relative x is greater then X upper, well then we've gotta limit our expansion
 		var/delta = max(final_x - x_delta_with, 0)
 		final_x -= delta
-	if(final_x > world.maxx && !cropMap)
+	if(final_x > world.maxx && !crop_map)
 		if(new_z)
 			// Need to avoid improperly loaded area/turf_contents
-			world.increaseMaxX(final_x, max_zs_to_load = z_offset - 1)
+			world.increase_max_x(final_x, map_load_z_cutoff = z_offset - 1)
 		else
-			world.increaseMaxX(final_x)
+			world.increase_max_x(final_x)
 		expanded_x = TRUE
 
 	var/lowest_x = max(x_lower, 1 - x_relative_to_absolute)
 
+	// Amount we offset the grid zcrd to get the true zcrd
+	var/grid_z_offset = z_offset - 1
+	var/z_upper_set = z_upper < INFINITY
+	var/z_lower_set = z_lower > -INFINITY
+
 	// We make the assumption that the last block of turfs will have the highest embedded z in it
-	var/highest_z = last_column.zcrd + z_offset - 1 // Lets not just make a new z level each time we increment maxz
+	// true max zcrd
+	var/map_bounds_z_max = last_column.zcrd
+	var/z_upper_parsed = map_bounds_z_max + z_offset - 1
+	if(z_upper_set)
+		z_upper_parsed -= map_bounds_z_max - z_upper
+	if(z_lower_set)
+		var/offset_amount = z_lower - 1
+		z_upper_parsed -= offset_amount
+		grid_z_offset -= offset_amount
+
+	var/list/target_grid_sets = gridSets
+	if(z_lower_set || z_upper_set) // bounds are set, filter out gridsets for z levels we don't want
+		target_grid_sets = filter_grid_sets_based_on_z_bounds(z_lower, z_upper)
+
 	var/z_threshold = world.maxz
-	if(highest_z > z_threshold && cropMap)
-		for(var/i in z_threshold + 1 to highest_z) //create a new z_level if needed
+	if(z_upper_parsed > z_threshold && crop_map)
+		for(var/i in z_threshold + 1 to z_upper_parsed) //create a new z_level if needed
 			world.incrementMaxZ()
 		if(!no_changeturf)
 			WARNING("Z-level expansion occurred without no_changeturf set, this may cause problems when /turf/AfterChange is called")
 
-	for(var/datum/grid_set/gset as anything in gridSets)
+	for(var/datum/grid_set/gset as anything in target_grid_sets)
 		var/true_xcrd = gset.xcrd + x_relative_to_absolute
 
 		// any cutoff of x means we just shouldn't iterate this gridset
 		if(final_x < true_xcrd || lowest_x > gset.xcrd)
 			continue
 
-		var/zcrd = gset.zcrd + z_offset - 1
+		var/zcrd = gset.zcrd + grid_z_offset
 		// If we're using changeturf, we disable it if we load into a z level we JUST created
 		var/no_afterchange = no_changeturf || zcrd > z_threshold
 
@@ -420,7 +502,7 @@
 			if(!cache)
 				SSatoms.map_loader_stop(REF(src))
 				CRASH("Undefined model key in DMM: [gset.gridLines[i]]")
-			build_coordinate(cache, locate(true_xcrd, ycrd, zcrd), no_afterchange, placeOnTop, new_z)
+			build_coordinate(cache, locate(true_xcrd, ycrd, zcrd), no_afterchange, place_on_top, new_z)
 
 			// only bother with bounds that actually exist
 			if(!first_found)
@@ -444,7 +526,7 @@
 /// Stanrdard loading, not used in production
 /// Doesn't take advantage of any tgm optimizations, which makes it slower but also more general
 /// Use this if for some reason your map format is messy
-/datum/parsed_map/proc/_dmm_load(x_offset, y_offset, z_offset, cropMap, no_changeturf, x_lower, x_upper, y_lower, y_upper, placeOnTop, new_z)
+/datum/parsed_map/proc/_dmm_load(x_offset, y_offset, z_offset, crop_map, no_changeturf, x_lower, x_upper, y_lower, y_upper, z_lower, z_upper, place_on_top, new_z)
 	// setup
 	var/list/modelCache = build_cache(no_changeturf)
 	var/space_key = modelCache[SPACE_KEY]
@@ -455,23 +537,46 @@
 	var/y_relative_to_absolute = y_offset - 1
 	var/x_relative_to_absolute = x_offset - 1
 	var/line_len = src.line_len
-	for(var/datum/grid_set/gset as anything in gridSets)
+
+	// Amount we offset the grid zcrd to get the true zcrd
+	var/grid_z_offset = z_offset - 1
+	var/z_upper_set = z_upper < INFINITY
+	var/z_lower_set = z_lower > -INFINITY
+
+	// we now need to find the maximum z, fun!
+	var/map_bounds_z_max = 1
+	for(var/datum/grid_set/grid_set as anything in gridSets)
+		map_bounds_z_max = max(map_bounds_z_max, grid_set.zcrd)
+
+	var/z_upper_parsed = map_bounds_z_max + z_offset - 1
+	if(z_upper_set)
+		z_upper_parsed -= map_bounds_z_max - z_upper
+	if(z_lower_set)
+		var/offset_amount = z_lower - 1
+		z_upper_parsed -= offset_amount
+		grid_z_offset -= offset_amount
+
+	var/list/target_grid_sets = gridSets
+	if(z_lower_set || z_upper_set) // bounds are set, filter out gridsets for z levels we don't want
+		target_grid_sets = filter_grid_sets_based_on_z_bounds(z_lower, z_upper)
+
+	for(var/datum/grid_set/gset as anything in target_grid_sets)
 		var/relative_x = gset.xcrd
 		var/relative_y = gset.ycrd
 		var/true_xcrd = relative_x + x_relative_to_absolute
 		var/ycrd = relative_y + y_relative_to_absolute
-		var/zcrd = gset.zcrd + z_offset - 1
-		if(!cropMap && ycrd > world.maxy)
+		var/zcrd = gset.zcrd + grid_z_offset
+		if(!crop_map && ycrd > world.maxy)
 			if(new_z)
 				// Need to avoid improperly loaded area/turf_contents
-				world.increaseMaxY(ycrd, max_zs_to_load = z_offset - 1)
+				world.increase_max_y(ycrd, map_load_z_cutoff = z_offset - 1)
 			else
-				world.increaseMaxY(ycrd)
+				world.increase_max_y(ycrd)
 			expanded_y = TRUE
 		var/zexpansion = zcrd > world.maxz
 		var/no_afterchange = no_changeturf
 		if(zexpansion)
-			if(cropMap)
+			if(crop_map)
 				continue
 			else
 				while (zcrd > world.maxz) //create a new z_level if needed
@@ -508,7 +613,7 @@
 		var/x_step_count = ROUND_UP(x_target / key_len)
 		var/final_x = relative_x + (x_step_count - 1)
 		var/x_delta_with = x_upper
-		if(cropMap)
+		if(crop_map)
 			// Take our smaller crop threshold yes?
 			x_delta_with = min(x_delta_with, world.maxx)
 		if(final_x > x_delta_with)
@@ -517,12 +622,12 @@
 			x_step_count -= delta
 			final_x -= delta
 			x_target = x_step_count * key_len
-		if(final_x > world.maxx && !cropMap)
+		if(final_x > world.maxx && !crop_map)
 			if(new_z)
 				// Need to avoid improperly loaded area/turf_contents
-				world.increaseMaxX(final_x, max_zs_to_load = z_offset - 1)
+				world.increase_max_x(final_x, map_load_z_cutoff = z_offset - 1)
 			else
-				world.increaseMaxX(final_x)
+				world.increase_max_x(final_x)
 			expanded_x = TRUE
 
 		// We're gonna track the first and last pairs of coords we find
@@ -553,7 +658,7 @@
 				if(!cache)
 					SSatoms.map_loader_stop(REF(src))
 					CRASH("Undefined model key in DMM: [model_key]")
-				build_coordinate(cache, locate(xcrd, ycrd, zcrd), no_afterchange, placeOnTop, new_z)
+				build_coordinate(cache, locate(xcrd, ycrd, zcrd), no_afterchange, place_on_top, new_z)
 
 				// only bother with bounds that actually exist
 				if(!first_found)

code/modules/mapping/ruins.dm

@@ -51,10 +51,10 @@
 		return central_turf
 
 /datum/map_template/ruin/proc/place_on_isolated_level(z)
-	var/datum/turf_reservation/reservation = SSmapping.RequestBlockReservation(width, height, z) //Make the new level creation work with different traits.
+	var/datum/turf_reservation/reservation = SSmapping.request_turf_block_reservation(width, height, 1, z) //Make the new level creation work with different traits.
 	if(!reservation)
 		return
-	var/turf/placement = locate(reservation.bottom_left_coords[1],reservation.bottom_left_coords[2],reservation.bottom_left_coords[3])
+	var/turf/placement = reservation.bottom_left_turfs[1]
 	load(placement)
 	loaded++
 	for(var/turf/T in get_affected_turfs(placement))

code/modules/mapping/space_management/multiz_helpers.dm

@@ -1,10 +1,11 @@
 /proc/get_step_multiz(ref, dir)
+	var/turf/us = get_turf(ref)
 	if(dir & UP)
 		dir &= ~UP
-		return get_step(GET_TURF_ABOVE(get_turf(ref)), dir)
+		return get_step(GET_TURF_ABOVE(us), dir)
 	if(dir & DOWN)
 		dir &= ~DOWN
-		return get_step(GET_TURF_BELOW(get_turf(ref)), dir)
+		return get_step(GET_TURF_BELOW(us), dir)
 	return get_step(ref, dir)
 
 /proc/get_dir_multiz(turf/us, turf/them)
@@ -15,27 +16,21 @@
 	if(us.z == them.z)
 		return get_dir(us, them)
 	else
-		var/turf/T = us.above()
+		var/turf/T = GET_TURF_ABOVE(us)
 		var/dir = NONE
 		if(T && (T.z == them.z))
 			dir = UP
 		else
-			T = us.below()
+			T = GET_TURF_BELOW(us)
 			if(T && (T.z == them.z))
 				dir = DOWN
 			else
 				return get_dir(us, them)
 		return (dir | get_dir(us, them))
 
-/turf/proc/above()
-	return GET_TURF_ABOVE(src)
-
-/turf/proc/below()
-	return GET_TURF_BELOW(src)
-
 /proc/get_lowest_turf(atom/ref)
 	var/turf/us = get_turf(ref)
-	var/next = GET_TURF_BELOW(us)
+	var/turf/next = GET_TURF_BELOW(us)
 	while(next)
 		us = next
 		next = GET_TURF_BELOW(us)
@@ -44,7 +39,7 @@
 // I wish this was lisp
 /proc/get_highest_turf(atom/ref)
 	var/turf/us = get_turf(ref)
-	var/next = GET_TURF_ABOVE(us)
+	var/turf/next = GET_TURF_ABOVE(us)
 	while(next)
 		us = next
 		next = GET_TURF_ABOVE(us)

code/modules/mapping/space_management/space_reservation.dm

@@ -1,16 +1,33 @@
 //Yes, they can only be rectangular.
 //Yes, I'm sorry.
 /datum/turf_reservation
+	/// All turfs that we've reserved
 	var/list/reserved_turfs = list()
-	///Turfs around the reservation for cordoning
+
+	/// Turfs around the reservation for cordoning
 	var/list/cordon_turfs = list()
-	///Area of turfs next to the cordon to fill with pre_cordon_area's
+
+	/// Area of turfs next to the cordon to fill with pre_cordon_area's
 	var/list/pre_cordon_turfs = list()
+
+	/// The width of the reservation
 	var/width = 0
+
+	/// The height of the reservation
 	var/height = 0
-	var/bottom_left_coords[3]
-	var/top_right_coords[3]
+
+	/// The z stack size of the reservation. Note that reservations are ALWAYS reserved from the bottom up
+	var/z_size = 0
+
+	/// List of the bottom left turfs. Indexed by what their z index for this reservation is
+	var/list/bottom_left_turfs = list()
+
+	/// List of the top right turfs. Indexed by what their z index for this reservation is
+	var/list/top_right_turfs = list()
+
+	/// The turf type the reservation is initially made with
 	var/turf_type = /turf/open/space
+
 	///Distance away from the cordon where we can put a "sort-cordon" and run some extra code (see make_repel). 0 makes nothing happen
 	var/pre_cordon_distance = 0
 
@@ -19,6 +36,9 @@
 	pre_cordon_distance = 7
 
 /datum/turf_reservation/proc/Release()
+	bottom_left_turfs.Cut()
+	top_right_turfs.Cut()
+
 	var/list/reserved_copy = reserved_turfs.Copy()
 	SSmapping.used_turfs -= reserved_turfs
 	reserved_turfs = list()
@@ -36,20 +56,20 @@
 	INVOKE_ASYNC(SSmapping, TYPE_PROC_REF(/datum/controller/subsystem/mapping, reserve_turfs), release_turfs)
 
 /// Attempts to calaculate and store a list of turfs around the reservation for cordoning. Returns whether a valid cordon was calculated
-/datum/turf_reservation/proc/calculate_cordon_turfs(turf/BL, turf/TR)
-	if(BL.x < 2 || BL.y < 2 || TR.x > (world.maxx - 2) || TR.y > (world.maxy - 2))
+/datum/turf_reservation/proc/calculate_cordon_turfs(turf/bottom_left, turf/top_right)
+	if(bottom_left.x < 2 || bottom_left.y < 2 || top_right.x > (world.maxx - 2) || top_right.y > (world.maxy - 2))
 		return FALSE // no space for a cordon here
 
-	var/list/possible_turfs = CORNER_OUTLINE(BL, width, height)
+	var/list/possible_turfs = CORNER_OUTLINE(bottom_left, width, height)
+	// if they're our cordon turfs, accept them
+	possible_turfs -= cordon_turfs
 	for(var/turf/cordon_turf as anything in possible_turfs)
-		if(!(cordon_turf.flags_1 & UNUSED_RESERVATION_TURF))
+		if(!(cordon_turf.turf_flags & UNUSED_RESERVATION_TURF))
 			return FALSE
-	cordon_turfs = possible_turfs
-
-	pre_cordon_turfs.Cut()
+	cordon_turfs |= possible_turfs
 
 	if(pre_cordon_distance)
-		var/turf/offset_turf = locate(BL.x + pre_cordon_distance, BL.y + pre_cordon_distance, BL.z)
+		var/turf/offset_turf = locate(bottom_left.x + pre_cordon_distance, bottom_left.y + pre_cordon_distance, bottom_left.z)
 		var/list/to_add = CORNER_OUTLINE(offset_turf, width - pre_cordon_distance * 2, height - pre_cordon_distance * 2) //we step-by-stop move inwards from the outer cordon
 		for(var/turf/turf_being_added as anything in to_add)
 			pre_cordon_turfs |= turf_being_added //add one by one so we can filter out duplicates
@@ -64,10 +84,11 @@
 		old_area.turfs_to_uncontain += cordon_turf
 		cordon_area.contained_turfs += cordon_turf
 		cordon_area.contents += cordon_turf
+		// Its no longer unused, but its also not "used"
+		cordon_turf.turf_flags &= ~UNUSED_RESERVATION_TURF
 		cordon_turf.ChangeTurf(/turf/cordon, /turf/cordon)
-
-		cordon_turf.flags_1 &= ~UNUSED_RESERVATION_TURF
 		SSmapping.unused_turfs["[cordon_turf.z]"] -= cordon_turf
+		// still gets linked to us though
 		SSmapping.used_turfs[cordon_turf] = src
 
 	//swap the area with the pre-cordoning area
@@ -113,7 +134,8 @@
 	if(!HAS_TRAIT(enterer, TRAIT_FREE_HYPERSPACE_SOFTCORDON_MOVEMENT))
 		space_dump(source, enterer)
 
-/datum/turf_reservation/proc/Reserve(width, height, zlevel)
+/// Internal proc which handles reserving the area for the reservation.
+/datum/turf_reservation/proc/_reserve_area(width, height, zlevel)
 	src.width = width
 	src.height = height
 	if(width > world.maxx || height > world.maxy || width < 1 || height < 1)
@@ -126,12 +148,12 @@
 	for(var/i in avail)
 		CHECK_TICK
 		BL = i
-		if(!(BL.flags_1 & UNUSED_RESERVATION_TURF))
+		if(!(BL.turf_flags & UNUSED_RESERVATION_TURF))
 			continue
 		if(BL.x + width > world.maxx || BL.y + height > world.maxy)
 			continue
 		TR = locate(BL.x + width - 1, BL.y + height - 1, BL.z)
-		if(!(TR.flags_1 & UNUSED_RESERVATION_TURF))
+		if(!(TR.turf_flags & UNUSED_RESERVATION_TURF))
 			continue
 		final = block(BL, TR)
 		if(!final)
@@ -139,7 +161,7 @@
 		passing = TRUE
 		for(var/I in final)
 			var/turf/checking = I
-			if(!(checking.flags_1 & UNUSED_RESERVATION_TURF))
+			if(!(checking.turf_flags & UNUSED_RESERVATION_TURF))
 				passing = FALSE
 				break
 		if(passing) // found a potentially valid area, now try to calculate its cordon
@@ -149,18 +171,94 @@
 		break
 	if(!passing || !istype(BL) || !istype(TR))
 		return FALSE
-	bottom_left_coords = list(BL.x, BL.y, BL.z)
-	top_right_coords = list(TR.x, TR.y, TR.z)
 	for(var/i in final)
 		var/turf/T = i
 		reserved_turfs |= T
-		T.flags_1 &= ~UNUSED_RESERVATION_TURF
 		SSmapping.unused_turfs["[T.z]"] -= T
 		SSmapping.used_turfs[T] = src
+		T.turf_flags = (T.turf_flags | RESERVATION_TURF) & ~UNUSED_RESERVATION_TURF
 		T.ChangeTurf(turf_type, turf_type)
+
+	bottom_left_turfs += BL
+	top_right_turfs += TR
+	return TRUE
+
+/datum/turf_reservation/proc/reserve(width, height, z_size, z_reservation)
+	src.z_size = z_size
+	var/failed_reservation = FALSE
+	for(var/_ in 1 to z_size)
+		if(!_reserve_area(width, height, z_reservation))
+			failed_reservation = TRUE
+			break
+
+	if(failed_reservation)
+		Release()
+		return FALSE
+
 	generate_cordon()
 	return TRUE
 
+/// Calculates the effective bounds information for the given turf. Returns a list of the information, or null if not applicable.
+/datum/turf_reservation/proc/calculate_turf_bounds_information(turf/target)
+	for(var/z_idx in 1 to z_size)
+		var/turf/bottom_left = bottom_left_turfs[z_idx]
+		var/turf/top_right = top_right_turfs[z_idx]
+		var/bl_x = bottom_left.x
+		var/bl_y = bottom_left.y
+		var/tr_x = top_right.x
+		var/tr_y = top_right.y
+
+		if(target.x < bl_x)
+			continue
+
+		if(target.y < bl_y)
+			continue
+
+		if(target.x > tr_x)
+			continue
+
+		if(target.y > tr_y)
+			continue
+
+		var/list/return_information = list()
+		return_information["z_idx"] = z_idx
+		return_information["offset_x"] = target.x - bl_x
+		return_information["offset_y"] = target.y - bl_y
+		return return_information
+	return null
+
+/// Gets the turf below the given target. Returns null if there is no turf below the target
+/datum/turf_reservation/proc/get_turf_below(turf/target)
+	var/list/bounds_info = calculate_turf_bounds_information(target)
+	if(isnull(bounds_info))
+		return null
+
+	var/z_idx = bounds_info["z_idx"]
+	// check what z level, if its the max, then there is no turf below
+	if(z_idx == z_size)
+		return null
+
+	var/offset_x = bounds_info["offset_x"]
+	var/offset_y = bounds_info["offset_y"]
+	var/turf/bottom_left = bottom_left_turfs[z_idx + 1]
+	return locate(bottom_left.x + offset_x, bottom_left.y + offset_y, bottom_left.z)
+
+/// Gets the turf above the given target. Returns null if there is no turf above the target
+/datum/turf_reservation/proc/get_turf_above(turf/target)
+	var/list/bounds_info = calculate_turf_bounds_information(target)
+	if(isnull(bounds_info))
+		return null
+
+	var/z_idx = bounds_info["z_idx"]
+	// check what z level, if its the min, then there is no turf above
+	if(z_idx == 1)
+		return null
+
+	var/offset_x = bounds_info["offset_x"]
+	var/offset_y = bounds_info["offset_y"]
+	var/turf/bottom_left = bottom_left_turfs[z_idx - 1]
+	return locate(bottom_left.x + offset_x, bottom_left.y + offset_y, bottom_left.z)
+
 /datum/turf_reservation/New()
 	LAZYADD(SSmapping.turf_reservations, src)