Support stations with multiple z-levels (#35339)

* Remove ZLEVEL_STATION_PRIMARY

* Add Up and Down traits for use by ladders and chasms

* Give map_config creation its own proc

* Combine LoadConfig and ValidateJSON and remove transition_config

* Make space linkage a z-level trait

* Remove ZLEVEL_EMPTY_SPACE

* Update uses of GetFullMapPath

* Handle multi-Z stations and load Lavaland and Reebe at runtime

* Remove unused space maps

* Fix inappropriate z-expansion in map reader, improve logging

* Update comments relating to z-level configuration

* Add Lavaland and Reebe to ALL_MAPS

_maps/_basemap.dm

@@ -1,16 +1,11 @@
 //#define LOWMEMORYMODE //uncomment this to load centcom and runtime station and thats it.
 
 #include "map_files\generic\CentCom.dmm"
-#include "map_files\generic\SpaceStation.dmm"
 
 #ifndef LOWMEMORYMODE
-
-	#include "map_files\generic\Space.dmm"
-	#include "map_files\generic\Space2.dmm"
-	#include "map_files\Mining\Lavaland.dmm"
-	#include "map_files\generic\City_of_Cogs.dmm"
-
 	#ifdef ALL_MAPS
+		#include "map_files\Mining\Lavaland.dmm"
+		#include "map_files\generic\City_of_Cogs.dmm"
 		#include "map_files\debug\runtimestation.dmm"
 		#include "map_files\Deltastation\DeltaStation2.dmm"
 		#include "map_files\MetaStation\MetaStation.dmm"

code/__DEFINES/maps.dm

@@ -1,46 +1,32 @@
 /*
-The /tg/ codebase currently requires you to have 11 z-levels of the same size dimensions.
-z-level order is important, the order you put them in inside the map config.dm will determine what z level number they are assigned ingame.
-Names of z-level do not matter, but order does greatly, for instances such as checking alive status of revheads on z1
+The /tg/ codebase allows mixing of hardcoded and dynamically-loaded z-levels.
+Z-levels can be reordered as desired and their properties are set by "traits".
+See map_config.dm for how a particular station's traits may be chosen.
+The list DEFAULT_MAP_TRAITS at the bottom of this file should correspond to
+the maps that are hardcoded, as set in _maps/_basemap.dm. SSmapping is
+responsible for loading every non-hardcoded z-level.
 
-current as of september 17, 2017
-z1 = station
-z2 = centcom
-z5 = mining
-z6 = city of cogs
-Everything else = randomized space
-Last space-z level = empty
+As of 2018-02-04, the typical z-levels for a single-level station are:
+1: CentCom
+2: Station
+3-4: Randomized space
+5: Mining
+6: City of Cogs
+7-11: Randomized space
+12: Empty space
+13: Transit space
+
+Multi-Z stations are supported and multi-Z mining and away missions would
+require only minor tweaks.
 */
 
-#define CROSSLINKED 2
-#define SELFLOOPING 1
-#define UNAFFECTED 0
-
-#define MAIN_STATION "Main Station"
-#define CENTCOM "CentCom"
-#define CITY_OF_COGS "City of Cogs"
-#define EMPTY_AREA_1 "Empty Area 1"
-#define EMPTY_AREA_2 "Empty Area 2"
-#define MINING_ASTEROID "Mining Asteroid"
-#define EMPTY_AREA_3 "Empty Area 3"
-#define EMPTY_AREA_4 "Empty Area 4"
-#define EMPTY_AREA_5 "Empty Area 5"
-#define EMPTY_AREA_6 "Empty Area 6"
-#define EMPTY_AREA_7 "Empty Area 7"
-#define EMPTY_AREA_8 "Empty Area 8"
-#define AWAY_MISSION "Away Mission"
-
-//for modifying jobs
+// helpers for modifying jobs, used in various job_changes.dm files
 #define MAP_JOB_CHECK if(SSmapping.config.map_name != JOB_MODIFICATION_MAP_NAME) { return; }
 #define MAP_JOB_CHECK_BASE if(SSmapping.config.map_name != JOB_MODIFICATION_MAP_NAME) { return ..(); }
 #define MAP_REMOVE_JOB(jobpath) /datum/job/##jobpath/map_check() { return (SSmapping.config.map_name != JOB_MODIFICATION_MAP_NAME) && ..() }
 
-//zlevel defines, can be overridden for different maps in the appropriate _maps file.
-#define ZLEVEL_STATION_PRIMARY 2
-#define ZLEVEL_EMPTY_SPACE 12
-
 #define SPACERUIN_MAP_EDGE_PAD 15
-#define ZLEVEL_SPACE_RUIN_COUNT 5
+#define ZLEVEL_SPACE_RUIN_COUNT 7
 
 // traits
 // boolean - marks a level as having that property if present
@@ -52,26 +38,40 @@ Last space-z level = empty
 #define ZTRAIT_AWAY "Away Mission"
 #define ZTRAIT_SPACE_RUINS "Space Ruins"
 #define ZTRAIT_LAVA_RUINS "Lava Ruins"
+
 // number - bombcap is multiplied by this before being applied to bombs
 #define ZTRAIT_BOMBCAP_MULTIPLIER "Bombcap Multiplier"
 
-// trait definitions
-#define DL_NAME "name"
-#define DL_LINKAGE "linkage"
-#define DL_TRAITS "traits"
+// numeric offsets - e.g. {"Down": -1} means that chasms will fall to z - 1 rather than oblivion
+#define ZTRAIT_UP "Up"
+#define ZTRAIT_DOWN "Down"
 
-#define DECLARE_LEVEL(NAME, LINKAGE, TRAITS) list(DL_NAME = NAME, DL_LINKAGE = LINKAGE, DL_TRAITS = TRAITS)
-// corresponds to basemap.dm
+// enum - how space transitions should affect this level
+#define ZTRAIT_LINKAGE "Linkage"
+    // UNAFFECTED if absent - no space transitions
+    #define UNAFFECTED null
+    // SELFLOOPING - space transitions always self-loop
+    #define SELFLOOPING "Self"
+    // CROSSLINKED - mixed in with the cross-linked space pool
+    #define CROSSLINKED "Cross"
+
+// default trait definitions, used by SSmapping
+#define ZTRAITS_CENTCOM list(ZTRAIT_LINKAGE = SELFLOOPING, ZTRAIT_CENTCOM = TRUE)
+#define ZTRAITS_STATION list(ZTRAIT_LINKAGE = CROSSLINKED, ZTRAIT_STATION = TRUE)
+#define ZTRAITS_SPACE list(ZTRAIT_LINKAGE = CROSSLINKED, ZTRAIT_SPACE_RUINS = TRUE)
+#define ZTRAITS_LAVALAND list(ZTRAIT_MINING = TRUE, ZTRAIT_LAVA_RUINS = TRUE, ZTRAIT_BOMBCAP_MULTIPLIER = 2)
+#define ZTRAITS_REEBE list(ZTRAIT_REEBE = TRUE, ZTRAIT_BOMBCAP_MULTIPLIER = 0.5)
+
+#define DL_NAME "name"
+#define DL_TRAITS "traits"
+#define DECLARE_LEVEL(NAME, TRAITS) list(DL_NAME = NAME, DL_TRAITS = TRAITS)
+
+// must correspond to _basemap.dm for things to work correctly
 #define DEFAULT_MAP_TRAITS list(\
-    DECLARE_LEVEL("CentCom", SELFLOOPING, list(ZTRAIT_CENTCOM = TRUE)),\
-    DECLARE_LEVEL("Main Station", CROSSLINKED, list(ZTRAIT_STATION = TRUE)),\
-    DECLARE_LEVEL("Empty Area 1", CROSSLINKED, list(ZTRAIT_SPACE_RUINS = TRUE)),\
-    DECLARE_LEVEL("Empty Area 2", CROSSLINKED, list(ZTRAIT_SPACE_RUINS = TRUE)),\
-    DECLARE_LEVEL("Lavaland", UNAFFECTED, list(ZTRAIT_MINING = TRUE, ZTRAIT_LAVA_RUINS = TRUE, ZTRAIT_BOMBCAP_MULTIPLIER = 2)),\
-    DECLARE_LEVEL("Reebe", UNAFFECTED, list(ZTRAIT_REEBE = TRUE, ZTRAIT_BOMBCAP_MULTIPLIER = 0.5)),\
+    DECLARE_LEVEL("CentCom", ZTRAITS_CENTCOM),\
 )
 
-//Camera lock flags
+// Camera lock flags
 #define CAMERA_LOCK_STATION 1
 #define CAMERA_LOCK_MINING 2
 #define CAMERA_LOCK_CENTCOM 4
@@ -85,4 +85,4 @@ Last space-z level = empty
 #define PLACE_DEFAULT "random"
 #define PLACE_SAME_Z "same"
 #define PLACE_SPACE_RUIN "space"
-#define PLACE_LAVA_RUIN "lavaland"
+#define PLACE_LAVA_RUIN "lavaland"

code/controllers/configuration/configuration.dm

@@ -236,7 +236,7 @@
 
 		switch (command)
 			if ("map")
-				currentmap = new ("_maps/[data].json")
+				currentmap = load_map_config("_maps/[data].json")
 				if(currentmap.defaulted)
 					log_config("Failed to load map config for [data]!")
 					currentmap = null

code/controllers/subsystem/mapping.dm

@@ -23,15 +23,19 @@ SUBSYSTEM_DEF(mapping)
 	var/loading_ruins = FALSE
 
 	// Z-manager stuff
+	var/station_start  // should only be used for maploading-related tasks
+	var/space_levels_so_far = 0
 	var/list/z_list
 	var/datum/space_level/transit
+	var/datum/space_level/empty_space
+	var/dmm_suite/loader
 
 /datum/controller/subsystem/mapping/PreInit()
 	if(!config)
 #ifdef FORCE_MAP
-		config = new(FORCE_MAP)
+		config = load_map_config(FORCE_MAP)
 #else
-		config = new(error_if_missing = FALSE)
+		config = load_map_config(error_if_missing = FALSE)
 #endif
 	return ..()
 
@@ -39,16 +43,20 @@ SUBSYSTEM_DEF(mapping)
 /datum/controller/subsystem/mapping/Initialize(timeofday)
 	if(config.defaulted)
 		to_chat(world, "<span class='boldannounce'>Unable to load next map config, defaulting to Box Station</span>")
+	loader = new
 	loadWorld()
 	repopulate_sorted_areas()
 	process_teleport_locs()			//Sets up the wizard teleport locations
 	preloadTemplates()
 #ifndef LOWMEMORYMODE
-	// Create space levels
-	for(var/I in 1 to ZLEVEL_SPACE_RUIN_COUNT)
-		add_new_zlevel("Empty Area [2 + I]", CROSSLINKED, list(ZTRAIT_SPACE_RUINS = TRUE))
-	add_new_zlevel("Empty Area [3 + ZLEVEL_SPACE_RUIN_COUNT]", CROSSLINKED, list())  // no ruins
-	transit = add_new_zlevel("Transit", UNAFFECTED, list(ZTRAIT_TRANSIT = TRUE))
+	// Create space ruin levels
+	while (space_levels_so_far < ZLEVEL_SPACE_RUIN_COUNT)
+		++space_levels_so_far
+		add_new_zlevel("Empty Area [space_levels_so_far]", ZTRAITS_SPACE)
+	// and one level with no ruins
+	empty_space = add_new_zlevel("Empty Area [1 + space_levels_so_far]", list(ZTRAIT_LINKAGE = CROSSLINKED))
+	// and the transit level
+	transit = add_new_zlevel("Transit", list(ZTRAIT_TRANSIT = TRUE))
 
 	// Pick a random away mission.
 	createRandomZlevel()
@@ -71,6 +79,7 @@ SUBSYSTEM_DEF(mapping)
 	// Set up Z-level transitions.
 	setup_map_transitions()
 	generate_station_area_list()
+	QDEL_NULL(loader)
 	..()
 
 /* Nuke threats, for making the blue tiles on the station go RED
@@ -108,32 +117,77 @@ SUBSYSTEM_DEF(mapping)
 
 	z_list = SSmapping.z_list
 
-/datum/controller/subsystem/mapping/proc/TryLoadZ(filename, errorList, forceLevel, last)
-	var/static/dmm_suite/loader
-	if(!loader)
-		loader = new
-	if(!loader.load_map(file(filename), 0, 0, forceLevel, no_changeturf = TRUE))
-		errorList |= filename
-	if(last)
-		QDEL_NULL(loader)
-
 #define INIT_ANNOUNCE(X) to_chat(world, "<span class='boldannounce'>[X]</span>"); log_world(X)
+/datum/controller/subsystem/mapping/proc/LoadGroup(list/errorList, name, path, files, list/traits, list/default_traits)
+	var/start_time = REALTIMEOFDAY
+
+	if (!islist(files))  // handle single-level maps
+		files = list(files)
+
+	// check that the total z count of all maps matches the list of traits
+	var/total_z = 0
+	for (var/file in files)
+		var/full_path = "_maps/[path]/[file]"
+		var/bounds = loader.load_map(file(full_path), 1, 1, 1, cropMap=FALSE, measureOnly=TRUE)
+		files[file] = total_z  // save the start Z of this file
+		total_z += bounds[MAP_MAXZ] - bounds[MAP_MINZ] + 1
+
+	if (!length(traits))  // null or empty - default
+		for (var/i in 1 to total_z)
+			traits += list(default_traits)
+	else if (total_z != traits.len)  // mismatch
+		INIT_ANNOUNCE("WARNING: [traits.len] trait sets specified for [total_z] z-levels in [path]!")
+		if (total_z < traits.len)  // ignore extra traits
+			traits.Cut(total_z + 1)
+		while (total_z > traits.len)  // fall back to defaults on extra levels
+			traits += list(default_traits)
+
+	// preload the relevant space_level datums
+	var/start_z = world.maxz + 1
+	var/i = 0
+	for (var/level in traits)
+		add_new_zlevel("[name][i ? " [i + 1]" : ""]", level)
+		++i
+
+	// load the maps
+	for (var/file in files)
+		var/full_path = "_maps/[path]/[file]"
+		if(!loader.load_map(file(full_path), 0, 0, start_z + files[file], no_changeturf = TRUE))
+			errorList |= full_path
+
+	INIT_ANNOUNCE("Loaded [name] in [(REALTIMEOFDAY - start_time)/10]s!")
+
 /datum/controller/subsystem/mapping/proc/loadWorld()
 	//if any of these fail, something has gone horribly, HORRIBLY, wrong
 	var/list/FailedZs = list()
 
-	var/start_time = REALTIMEOFDAY
-
-	INIT_ANNOUNCE("Loading [config.map_name]...")
-	TryLoadZ(config.GetFullMapPath(), FailedZs, ZLEVEL_STATION_PRIMARY)
+	// ensure we have space_level datums for compiled-in maps
 	InitializeDefaultZLevels()
-	INIT_ANNOUNCE("Loaded station in [(REALTIMEOFDAY - start_time)/10]s!")
+
+	// load the station
+	station_start = world.maxz + 1
+	INIT_ANNOUNCE("Loading [config.map_name]...")
+	LoadGroup(FailedZs, "Station", config.map_path, config.map_file, config.traits, ZTRAITS_STATION)
+
 	if(SSdbcore.Connect())
 		var/datum/DBQuery/query_round_map_name = SSdbcore.NewQuery("UPDATE [format_table_name("round")] SET map_name = '[config.map_name]' WHERE id = [GLOB.round_id]")
 		query_round_map_name.Execute()
 
-	if(config.minetype != "lavaland")
-		INIT_ANNOUNCE("WARNING: A map without lavaland set as its minetype was loaded! This is being ignored! Update the maploader code!")
+#ifndef LOWMEMORYMODE
+	// TODO: remove this when the DB is prepared for the z-levels getting reordered
+	while (world.maxz < (5 - 1) && space_levels_so_far < ZLEVEL_SPACE_RUIN_COUNT)
+		++space_levels_so_far
+		add_new_zlevel("Empty Area [space_levels_so_far]", ZTRAITS_SPACE)
+
+	// load mining
+	if(config.minetype == "lavaland")
+		LoadGroup(FailedZs, "Lavaland", "map_files/Mining", "Lavaland.dmm", default_traits = ZTRAITS_LAVALAND)
+	else if (!isnull(config.minetype))
+		INIT_ANNOUNCE("WARNING: An unknown minetype '[config.minetype]' was set! This is being ignored! Update the maploader code!")
+
+	// load Reebe
+	LoadGroup(FailedZs, "Reebe", "map_files/generic", "City_of_Cogs.dmm", default_traits = ZTRAITS_REEBE)
+#endif
 
 	if(LAZYLEN(FailedZs))	//but seriously, unless the server's filesystem is messed up this will never happen
 		var/msg = "RED ALERT! The following map files failed to load: [FailedZs[1]]"
@@ -209,7 +263,7 @@ GLOBAL_LIST_EMPTY(the_station_areas)
 
 /datum/controller/subsystem/mapping/proc/changemap(var/datum/map_config/VM)
 	if(!VM.MakeNextMap())
-		next_map_config = new(default_to_box = TRUE)
+		next_map_config = load_map_config(default_to_box = TRUE)
 		message_admins("Failed to set new map with next_map.json for [VM.map_name]! Using default as backup!")
 		return
 

code/controllers/subsystem/minimap.dm

@@ -9,7 +9,10 @@ SUBSYSTEM_DEF(minimap)
 
 /datum/controller/subsystem/minimap/Initialize(timeofday)
 	z_levels = SSmapping.levels_by_trait(ZTRAIT_STATION)
-	var/hash = md5(SSmapping.config.GetFullMapPath())
+	var/list/hashlist = list()
+	for (var/file in SSmapping.config.GetFullMapPaths())
+		hashlist += md5(file2text(file))
+	var/hash = hashlist.Join("\n")
 	if(CONFIG_GET(flag/generate_minimaps))
 		if(hash == trim(file2text(hash_path())))
 			for(var/z in z_levels)	//We have these files cached, let's register them

code/controllers/subsystem/persistence.dm

@@ -56,7 +56,7 @@ SUBSYSTEM_DEF(persistence)
 		old_secret_satchels.Cut(pos, pos+1 % old_secret_satchels.len)
 		F.x = old_secret_satchels[pos]["x"]
 		F.y = old_secret_satchels[pos]["y"]
-		F.z = ZLEVEL_STATION_PRIMARY
+		F.z = SSmapping.station_start
 		path = text2path(old_secret_satchels[pos]["saved_obj"])
 
 	if(F)
@@ -67,7 +67,7 @@ SUBSYSTEM_DEF(persistence)
 			spawned_objects[spawned_item] = TRUE
 		placed_satchel++
 	var/free_satchels = 0
-	for(var/turf/T in shuffle(block(locate(TRANSITIONEDGE,TRANSITIONEDGE,ZLEVEL_STATION_PRIMARY), locate(world.maxx-TRANSITIONEDGE,world.maxy-TRANSITIONEDGE,ZLEVEL_STATION_PRIMARY)))) //Nontrivially expensive but it's roundstart only
+	for(var/turf/T in shuffle(block(locate(TRANSITIONEDGE,TRANSITIONEDGE,SSmapping.station_start), locate(world.maxx-TRANSITIONEDGE,world.maxy-TRANSITIONEDGE,SSmapping.station_start)))) //Nontrivially expensive but it's roundstart only
 		if(isfloorturf(T) && !isplatingturf(T))
 			new /obj/item/storage/backpack/satchel/flat/secret(T)
 			free_satchels++
@@ -189,7 +189,7 @@ SUBSYSTEM_DEF(persistence)
 	var/list/satchels_to_add = list()
 	for(var/A in new_secret_satchels)
 		var/obj/item/storage/backpack/satchel/flat/F = A
-		if(QDELETED(F) || F.z != ZLEVEL_STATION_PRIMARY || F.invisibility != INVISIBILITY_MAXIMUM)
+		if(QDELETED(F) || F.z != SSmapping.station_start || F.invisibility != INVISIBILITY_MAXIMUM)
 			continue
 		var/list/savable_obj = list()
 		for(var/obj/O in F)

code/datums/map_config.dm

@@ -4,46 +4,42 @@
 //  -Cyberboss
 
 /datum/map_config
+	// Metadata
 	var/config_filename = "_maps/boxstation.json"
+	var/defaulted = TRUE  // set to FALSE by LoadConfig() succeeding
+	// Config from maps.txt
+	var/config_max_users = 0
+	var/config_min_users = 0
+	var/voteweight = 1
+
+	// Config actually from the JSON - should default to Box
 	var/map_name = "Box Station"
 	var/map_path = "map_files/BoxStation"
 	var/map_file = "BoxStation.dmm"
 
+	var/traits = null
+
 	var/minetype = "lavaland"
 
+	var/allow_custom_shuttles = TRUE
 	var/shuttles = list(
 		"cargo" = "cargo_box",
 		"ferry" = "ferry_fancy",
 		"whiteship" = "whiteship_box",
 		"emergency" = "emergency_box")
 
-	//Order matters here.
-	var/list/transition_config = list(CENTCOM = SELFLOOPING,
-									MAIN_STATION = CROSSLINKED,
-									EMPTY_AREA_1 = CROSSLINKED,
-									EMPTY_AREA_2 = CROSSLINKED,
-									MINING = SELFLOOPING,
-									CITY_OF_COGS = SELFLOOPING,
-									EMPTY_AREA_3 = CROSSLINKED,
-									EMPTY_AREA_4 = CROSSLINKED,
-									EMPTY_AREA_5 = CROSSLINKED,
-									EMPTY_AREA_6 = CROSSLINKED,
-									EMPTY_AREA_7 = CROSSLINKED,
-									EMPTY_AREA_8 = CROSSLINKED)
-	var/defaulted = TRUE    //if New failed
-
-	var/config_max_users = 0
-	var/config_min_users = 0
-	var/voteweight = 1
-	var/allow_custom_shuttles = TRUE
-
-/datum/map_config/New(filename = "data/next_map.json", default_to_box, delete_after, error_if_missing = TRUE)
-	if(default_to_box)
-		return
-	LoadConfig(filename, error_if_missing)
-	if(delete_after)
+/proc/load_map_config(filename = "data/next_map.json", default_to_box, delete_after, error_if_missing = TRUE)
+	var/datum/map_config/config = new
+	if (default_to_box)
+		return config
+	if (!config.LoadConfig(filename, error_if_missing))
+		qdel(config)
+		config = new /datum/map_config  // Fall back to Box
+	if (delete_after)
 		fdel(filename)
+	return config
 
+#define CHECK_EXISTS(X) if(!istext(json[X])) { log_world("[##X] missing from json!"); return; }
 /datum/map_config/proc/LoadConfig(filename, error_if_missing)
 	if(!fexists(filename))
 		if(error_if_missing)
@@ -65,99 +61,66 @@
 		log_world("map_config is not json: [filename]")
 		return
 
-	if(!ValidateJSON(json))
-		log_world("map_config failed to validate for above reason: [filename]")
-		return
-
 	config_filename = filename
 
+	CHECK_EXISTS("map_name")
 	map_name = json["map_name"]
+	CHECK_EXISTS("map_path")
 	map_path = json["map_path"]
-	map_file = json["map_file"]
 
-	if(islist(json["shuttles"]))
+	map_file = json["map_file"]
+	// "map_file": "BoxStation.dmm"
+	if (istext(map_file))
+		if (!fexists("_maps/[map_path]/[map_file]"))
+			log_world("Map file ([map_path]/[map_file]) does not exist!")
+			return
+	// "map_file": ["Lower.dmm", "Upper.dmm"]
+	else if (islist(map_file))
+		for (var/file in map_file)
+			if (!fexists("_maps/[map_path]/[file]"))
+				log_world("Map file ([map_path]/[file]) does not exist!")
+				return
+	else
+		log_world("map_file missing from json!")
+		return
+
+	if (islist(json["shuttles"]))
 		var/list/L = json["shuttles"]
 		for(var/key in L)
 			var/value = L[key]
 			shuttles[key] = value
-
-	minetype = json["minetype"] || minetype
-	allow_custom_shuttles = json["allow_custom_shuttles"] != FALSE
-
-	var/jtcl = json["transition_config"]
-	if(jtcl && jtcl != "default")
-		transition_config.Cut()
-
-		for(var/I in jtcl)
-			transition_config[TransitionStringToEnum(I)] = TransitionStringToEnum(jtcl[I])
-
-	defaulted = FALSE
-
-#define CHECK_EXISTS(X) if(!istext(json[X])) { log_world("[##X] missing from json!"); return; }
-/datum/map_config/proc/ValidateJSON(list/json)
-	CHECK_EXISTS("map_name")
-	CHECK_EXISTS("map_path")
-	CHECK_EXISTS("map_file")
-
-	var/shuttles = json["shuttles"]
-	if(shuttles && !islist(shuttles))
-		log_world("json\[shuttles\] is not a list!")
-
-	var/path = GetFullMapPath(json["map_path"], json["map_file"])
-	if(!fexists(path))
-		log_world("Map file ([path]) does not exist!")
+	else if ("shuttles" in json)
+		log_world("map_config shuttles is not a list!")
 		return
 
-	var/tc = json["transition_config"]
-	if(tc != null && tc != "default")
-		if(!islist(tc))
-			log_world("transition_config is not a list!")
-			return
+	traits = json["traits"]
+	// "traits": [{"Linkage": "Cross"}, {"Space Ruins": true}]
+	if (islist(traits))
+		// "Station" is set by default, but it's assumed if you're setting
+		// traits you want to customize which level is cross-linked
+		for (var/level in traits)
+			if (!(ZTRAIT_STATION in level))
+				level[ZTRAIT_STATION] = TRUE
+	// "traits": null or absent -> default
+	else if (!isnull(traits))
+		log_world("map_config traits is not a list!")
+		return
 
-		for(var/I in tc)
-			if(isnull(TransitionStringToEnum(I)))
-				log_world("Invalid transition_config option: [I]!")
-			if(isnull(TransitionStringToEnum(tc[I])))
-				log_world("Invalid transition_config option: [I]!")
+	if ("minetype" in json)
+		minetype = json["minetype"]
 
+	allow_custom_shuttles = json["allow_custom_shuttles"] != FALSE
+
+	defaulted = FALSE
 	return TRUE
 #undef CHECK_EXISTS
 
-/datum/map_config/proc/TransitionStringToEnum(string)
-	switch(string)
-		if("CROSSLINKED")
-			return CROSSLINKED
-		if("SELFLOOPING")
-			return SELFLOOPING
-		if("UNAFFECTED")
-			return UNAFFECTED
-		if("MAIN_STATION")
-			return MAIN_STATION
-		if("CENTCOM")
-			return CENTCOM
-		if("CITY_OF_COGS")
-			return CITY_OF_COGS
-		if("MINING")
-			return MINING
-		if("EMPTY_AREA_1")
-			return EMPTY_AREA_1
-		if("EMPTY_AREA_2")
-			return EMPTY_AREA_2
-		if("EMPTY_AREA_3")
-			return EMPTY_AREA_3
-		if("EMPTY_AREA_4")
-			return EMPTY_AREA_4
-		if("EMPTY_AREA_5")
-			return EMPTY_AREA_5
-		if("EMPTY_AREA_6")
-			return EMPTY_AREA_6
-		if("EMPTY_AREA_7")
-			return EMPTY_AREA_7
-		if("EMPTY_AREA_8")
-			return EMPTY_AREA_8
-
-/datum/map_config/proc/GetFullMapPath(mp = map_path, mf = map_file)
-	return "_maps/[mp]/[mf]"
+/datum/map_config/proc/GetFullMapPaths()
+	if (istext(map_file))
+		return list("_maps/[map_path]/[map_file]")
+	. = list()
+	for (var/file in map_file)
+		. += "_maps/[map_path]/[file]"
 
 /datum/map_config/proc/MakeNextMap()
 	return config_filename == "data/next_map.json" || fcopy(config_filename, "data/next_map.json")

code/game/objects/structures/ladders.dm

@@ -35,19 +35,20 @@
 /obj/structure/ladder/LateInitialize()
 	// By default, discover ladders above and below us vertically
 	var/turf/T = get_turf(src)
+	var/obj/structure/ladder/L
 
 	if (!down)
-		for (var/obj/structure/ladder/L in locate(T.x, T.y, T.z - 1))
+		L = locate() in SSmapping.get_turf_below(T)
+		if (L)
 			down = L
 			L.up = src  // Don't waste effort looping the other way
 			L.update_icon()
-			break
 	if (!up)
-		for (var/obj/structure/ladder/L in locate(T.x, T.y, T.z + 1))
+		L = locate() in SSmapping.get_turf_above(T)
+		if (L)
 			up = L
 			L.down = src  // Don't waste effort looping the other way
 			L.update_icon()
-			break
 
 	update_icon()
 

code/game/turfs/simulated/chasm.dm

@@ -11,7 +11,7 @@
 
 /turf/open/chasm/Initialize()
 	. = ..()
-	AddComponent(/datum/component/chasm, null)
+	AddComponent(/datum/component/chasm, SSmapping.get_turf_below(src))
 
 /turf/open/chasm/proc/set_target(turf/target)
 	GET_COMPONENT(chasm_component, /datum/component/chasm)
@@ -64,16 +64,6 @@
 /turf/open/chasm/CanPass(atom/movable/mover, turf/target)
 	return 1
 
-
-// Naive "down" which just subtracts a z-level
-/turf/open/chasm/straight_down
-	baseturfs = /turf/open/chasm/straight_down
-
-/turf/open/chasm/straight_down/Initialize()
-	. = ..()
-	set_target(locate(x, y, z - 1))
-
-
 // Chasms for Lavaland, with planetary atmos and lava glow
 /turf/open/chasm/lavaland
 	initial_gas_mix = LAVALAND_DEFAULT_ATMOS
@@ -95,10 +85,3 @@
 	underlay_appearance.icon = 'icons/turf/floors.dmi'
 	underlay_appearance.icon_state = "dirt"
 	return TRUE
-
-/turf/open/chasm/jungle/straight_down
-	baseturfs = /turf/open/chasm/jungle/straight_down
-
-/turf/open/chasm/jungle/straight_down/Initialize(mapload)
-	. = ..()
-	set_target(locate(x, y, z - 1))

code/game/turfs/simulated/floor/plating/dirt.dm

@@ -3,7 +3,7 @@
 	desc = "Upon closer examination, it's still dirt."
 	icon = 'icons/turf/floors.dmi'
 	icon_state = "dirt"
-	baseturfs = /turf/open/chasm/jungle/straight_down
+	baseturfs = /turf/open/chasm/jungle
 	initial_gas_mix = LAVALAND_DEFAULT_ATMOS
 	planetary_atmos = TRUE
 	attachment_holes = FALSE

code/game/turfs/space/transit.dm

@@ -40,12 +40,10 @@
 	var/min = 1+TRANSITIONEDGE
 
 	var/list/possible_transtitons = list()
-	var/k = 1
-	var/list/config_list = SSmapping.config.transition_config
-	for(var/a in config_list)
-		if(config_list[a] == CROSSLINKED) // Only pick z-levels connected to station space
-			possible_transtitons += k
-		k++
+	for(var/A in SSmapping.z_list)
+		var/datum/space_level/D = A
+		if (D.linkage == CROSSLINKED)
+			possible_transtitons += D.z_value
 	var/_z = pick(possible_transtitons)
 
 	//now select coordinates for a border turf

code/modules/events/pirates.dm

@@ -60,7 +60,7 @@
 	var/datum/map_template/pirate_event_ship/ship = new
 	var/x = rand(TRANSITIONEDGE,world.maxx - TRANSITIONEDGE - ship.width)
 	var/y = rand(TRANSITIONEDGE,world.maxy - TRANSITIONEDGE - ship.height)
-	var/z = ZLEVEL_EMPTY_SPACE
+	var/z = SSmapping.empty_space.z_value
 	var/turf/T = locate(x,y,z)
 	if(!T)
 		CRASH("Pirate event found no turf to load in")

code/modules/mapping/map_template.dm

@@ -52,7 +52,7 @@
 	var/x = round((world.maxx - width)/2)
 	var/y = round((world.maxy - height)/2)
 
-	var/datum/space_level/level = SSmapping.add_new_zlevel(name, UNAFFECTED, list(ZTRAIT_AWAY = TRUE))
+	var/datum/space_level/level = SSmapping.add_new_zlevel(name, list(ZTRAIT_AWAY = TRUE))
 	var/list/bounds = maploader.load_map(file(mappath), x, y, level.z_value, no_changeturf=(SSatoms.initialized == INITIALIZATION_INSSATOMS), placeOnTop=TRUE)
 	if(!bounds)
 		return FALSE

code/modules/mapping/reader.dm

@@ -94,7 +94,7 @@ GLOBAL_DATUM_INIT(_preloader, /dmm_suite/preloader, new)
 			var/zcrd = text2num(dmmRegex.group[5]) + z_offset - 1
 
 			var/zexpansion = zcrd > world.maxz
-			if(zexpansion)
+			if(zexpansion && !measureOnly)
 				if(cropMap)
 					continue
 				else

code/modules/mapping/space_management/space_level.dm

@@ -1,5 +1,5 @@
 /datum/space_level
-	var/name = "Your config settings failed, you need to fix this for the datum space levels to work"
+	var/name = "NAME MISSING"
 	var/list/neigbours = list()
 	var/list/traits
 	var/z_value = 1 //actual z placement
@@ -7,8 +7,8 @@
 	var/xi
 	var/yi   //imaginary placements on the grid
 
-/datum/space_level/New(new_z, new_name, new_linkage = SELFLOOPING, list/new_traits = list())
+/datum/space_level/New(new_z, new_name, list/new_traits = list())
 	z_value = new_z
 	name = new_name
 	traits = new_traits
-	set_linkage(new_linkage)
+	set_linkage(new_traits[ZTRAIT_LINKAGE])

code/modules/mapping/space_management/space_transition.dm

@@ -1,9 +1,8 @@
 /datum/space_level/proc/set_linkage(new_linkage)
 	linkage = new_linkage
 	if(linkage == SELFLOOPING)
-		neigbours = list()
-		var/list/L = list(TEXT_NORTH,TEXT_SOUTH,TEXT_EAST,TEXT_WEST)
-		for(var/A in L)
+		neigbours = list(TEXT_NORTH,TEXT_SOUTH,TEXT_EAST,TEXT_WEST)
+		for(var/A in neigbours)
 			neigbours[A] = src
 
 /datum/space_level/proc/set_neigbours(list/L)

code/modules/mapping/space_management/traits.dm

@@ -1,15 +1,19 @@
 // Look up levels[z].traits[trait]
 /datum/controller/subsystem/mapping/proc/level_trait(z, trait)
-	if (!z)
+	if (!isnum(z) || z < 1)
 		return null
-	var/list/trait_list
 	if (z_list)
+		if (z > z_list.len)
+			stack_trace("Unmanaged z-level [z]! maxz = [world.maxz], z_list.len = [z_list.len]")
+			return list()
 		var/datum/space_level/S = get_level(z)
-		trait_list = S.traits
+		return S.traits[trait]
 	else
-		var/list/default_map_traits = DEFAULT_MAP_TRAITS
-		trait_list = default_map_traits[z][DL_TRAITS]
-	return trait_list[trait]
+		var/list/default = DEFAULT_MAP_TRAITS
+		if (z > default.len)
+			stack_trace("Unmanaged z-level [z]! maxz = [world.maxz], default.len = [default.len]")
+			return list()
+		return default[z][DL_TRAITS][trait]
 
 // Check if levels[z] has any of the specified traits
 /datum/controller/subsystem/mapping/proc/level_has_any_trait(z, list/traits)
@@ -45,6 +49,24 @@
 				. += S.z_value
 				break
 
+// Attempt to get the turf below the provided one according to Z traits
+/datum/controller/subsystem/mapping/proc/get_turf_below(turf/T)
+	if (!T)
+		return
+	var/offset = level_trait(T.z, ZTRAIT_DOWN)
+	if (!offset)
+		return
+	return locate(T.x, T.y, T.z + offset)
+
+// Attempt to get the turf above the provided one according to Z traits
+/datum/controller/subsystem/mapping/proc/get_turf_above(turf/T)
+	if (!T)
+		return
+	var/offset = level_trait(T.z, ZTRAIT_UP)
+	if (!offset)
+		return
+	return locate(T.x, T.y, T.z + offset)
+
 // Prefer not to use this one too often
 /datum/controller/subsystem/mapping/proc/get_station_center()
 	var/station_z = levels_by_trait(ZTRAIT_STATION)[1]

code/modules/mapping/space_management/zlevel_manager.dm

@@ -13,20 +13,20 @@
 
 	for (var/I in 1 to default_map_traits.len)
 		var/list/features = default_map_traits[I]
-		var/datum/space_level/S = new(I, features[DL_NAME], features[DL_LINKAGE], features[DL_TRAITS])
+		var/datum/space_level/S = new(I, features[DL_NAME], features[DL_TRAITS])
 		z_list += S
 
-/datum/controller/subsystem/mapping/proc/add_new_zlevel(name, linkage = SELFLOOPING, traits = list(), z_type = /datum/space_level)
+/datum/controller/subsystem/mapping/proc/add_new_zlevel(name, traits = list(), z_type = /datum/space_level)
 	var/new_z = z_list.len + 1
 	if (world.maxz < new_z)
 		world.incrementMaxZ()
 		CHECK_TICK
 	// TODO: sleep here if the Z level needs to be cleared
-	var/datum/space_level/S = new z_type(new_z, name, linkage, traits)
+	var/datum/space_level/S = new z_type(new_z, name, traits)
 	z_list += S
 	return S
 
 /datum/controller/subsystem/mapping/proc/get_level(z)
-	. = z_list[z]
-	if (!.)
-		CRASH("Unmanaged z-level: '[z]'")
+	if (z_list && z >= 1 && z <= z_list.len)
+		return z_list[z]
+	CRASH("Unmanaged z-level [z]! maxz = [world.maxz], z_list.len = [z_list ? z_list.len : "null"]")

code/modules/procedural_mapping/mapGenerators/repair.dm

@@ -20,11 +20,15 @@
 	if(!istype(mother, /datum/mapGenerator/repair/reload_station_map))
 		return
 	var/datum/mapGenerator/repair/reload_station_map/mother1 = mother
-	if(!is_station_level(mother1.z))
-		return			//This is only for reloading station blocks!
 	GLOB.reloading_map = TRUE
 	var/static/dmm_suite/reloader = new
-	var/list/bounds = reloader.load_map(file(SSmapping.config.GetFullMapPath()),measureOnly = FALSE, no_changeturf = FALSE,x_offset = 0, y_offset = 0, z_offset = ZLEVEL_STATION_PRIMARY, cropMap=TRUE, lower_crop_x = mother1.x_low, lower_crop_y = mother1.y_low, upper_crop_x = mother1.x_high, upper_crop_y = mother1.y_high)
+	// This is kind of finicky on multi-Z maps but the reader would need to be
+	// changed to allow Z cropping and that's a mess
+	var/z_offset = SSmapping.station_start
+	var/list/bounds
+	for (var/path in SSmapping.config.GetFullMapPaths())
+		bounds = reloader.load_map(file(path), measureOnly = FALSE, no_changeturf = FALSE,x_offset = 0, y_offset = 0, z_offset = z_offset, cropMap=TRUE, lower_crop_x = mother1.x_low, lower_crop_y = mother1.y_low, upper_crop_x = mother1.x_high, upper_crop_y = mother1.y_high)
+		z_offset += bounds[MAP_MAXZ] - bounds[MAP_MINZ] + 1
 
 	var/list/obj/machinery/atmospherics/atmos_machines = list()
 	var/list/obj/structure/cable/cables = list()
@@ -32,8 +36,8 @@
 
 	repopulate_sorted_areas()
 
-	for(var/L in block(locate(bounds[MAP_MINX], bounds[MAP_MINY], bounds[MAP_MINZ]),
-	                   locate(bounds[MAP_MAXX], bounds[MAP_MAXY], bounds[MAP_MAXZ])))
+	for(var/L in block(locate(bounds[MAP_MINX], bounds[MAP_MINY], SSmapping.station_start),
+	                   locate(bounds[MAP_MAXX], bounds[MAP_MAXY], z_offset - 1)))
 		set waitfor = FALSE
 		var/turf/B = L
 		atoms += B
@@ -93,7 +97,7 @@
 	y_low = min(start.y, end.y)
 	x_high = max(start.x, end.x)
 	y_high = max(start.y, end.y)
-	z = ZLEVEL_STATION_PRIMARY
+	z = SSmapping.station_start
 
 GLOBAL_VAR_INIT(reloading_map, FALSE)
 

code/modules/ruins/objects_and_mobs/sin_ruins.dm

@@ -100,9 +100,16 @@
 /obj/structure/mirror/magic/pride/curse(mob/user)
 	user.visible_message("<span class='danger'><B>The ground splits beneath [user] as [user.p_their()] hand leaves the mirror!</B></span>", \
 	"<span class='notice'>Perfect. Much better! Now <i>nobody</i> will be able to resist yo-</span>")
+
 	var/turf/T = get_turf(user)
-	T.ChangeTurf(/turf/open/chasm/straight_down)
+	var/list/levels = SSmapping.levels_by_trait(ZTRAIT_SPACE_RUINS)
+	var/turf/dest
+	if (levels.len)
+		dest = locate(T.x, T.y, pick(levels))
+
+	T.ChangeTurf(/turf/open/chasm)
 	var/turf/open/chasm/C = T
+	C.set_target(dest)
 	C.drop(user)
 
 //can't be bothered to do sloth right now, will make later