Fixes multi-z things.

code/modules/multiz/_stubs.dm

@@ -9,8 +9,8 @@
 // FOR THE LOVE OF GOD USE THESE.  DO NOT FUCKING SPAGHETTIFY THIS.
 // Use the Has*() functions if you ONLY need to check.
 // If you need to do something, use Get*().
-proc/HasAbove(var/z)
-proc/HasBelow(var/z)
+HasAbove(var/z)
+HasBelow(var/z)
 // These give either the turf or null.
-proc/GetAbove(var/turf/turf)
-proc/GetBelow(var/turf/turf)
+GetAbove(var/atom/atom)
+GetBelow(var/atom/atom)

code/modules/multiz/basic.dm

@@ -4,28 +4,32 @@ var/z_levels = 0 // Each bit represents a connection between adjacent levels.  S
 
 // If the height is more than 1, we mark all contained levels as connected.
 /obj/effect/landmark/map_data/New()
-	for(var/i = z - 1 to height - 2)
-		z_levels |= 1 << i
-	del src
+	ASSERT(height <= z)
+	// Due to the offsets of how connections are stored v.s. how z-levels are indexed, some magic number silliness happened.
+	for(var/i = (z - height) to (z - 2))
+		z_levels |= (1 << i)
+	qdel(src)
 
-HasAbove(z)
-	if(z > world.maxz || z > 17 || z < 2)
+// The storage of connections between adjacent levels means some bitwise magic is needed.
+proc/HasAbove(var/z)
+	if(z >= world.maxz || z > 16 || z < 1)
 		return 0
 	return z_levels & (1 << (z - 1))
 
-HasBelow(z)
-	if(z >= world.maxz || z > 16 || z < 1)
+proc/HasBelow(var/z)
+	if(z > world.maxz || z > 17 || z < 2)
 		return 0
-	return z_levels & (1 << z)
+	return z_levels & (1 << (z - 2))
 
-GetAbove(var/atom/thing)
-	var/turf/turf = get_turf(thing)
-	if(!istype(turf))
+// Thankfully, no bitwise magic is needed here.
+proc/GetAbove(var/atom/atom)
+	var/turf/turf = get_turf(atom)
+	if(!turf)
 		return null
-	return HasBelow(turf.z) ? locate(turf.z, turf.y, turf.z - 1) : null
+	return HasAbove(turf.z) ? get_step(turf, UP) : null
 
-GetBelow(var/atom/thing)
-	var/turf/turf = get_turf(thing)
-	if(!istype(turf))
+proc/GetBelow(var/atom/atom)
+	var/turf/turf = get_turf(atom)
+	if(!turf)
 		return null
-	return HasBelow(turf.z) ? locate(turf.z, turf.y, turf.z + 1) : null
+	return HasBelow(turf.z) ? get_step(turf, DOWN) : null

code/modules/multiz/disabled.dm

@@ -0,0 +1,10 @@
+
+proc/HasAbove(var/z)
+	return 0
+proc/HasBelow(var/z)
+	return 0
+// These give either the turf or null.
+proc/GetAbove(var/turf/turf)
+	return null
+proc/GetBelow(var/turf/turf)
+	return null

code/modules/multiz/movement.dm

@@ -0,0 +1,51 @@
+/obj/item/weapon/tank/jetpack/verb/moveup()
+	set name = "Move Upwards"
+	set category = "Object"
+
+	. = 1
+	if(!allow_thrust(0.01, usr))
+		usr << "<span class='warning'>\The [src] is disabled.</span>"
+		return
+
+	var/turf/above = GetAbove(src)
+	if(!istype(above))
+		usr << "<span class='notice'>There is nothing of interest in this direction.</span>"
+		return
+
+	if(!istype(above, /turf/space) && !istype(above, /turf/simulated/open))
+		usr << "<span class='warning'>You bump against \the [above].</span>"
+		return
+
+	for(var/atom/A in above)
+		if(A.density)
+			usr << "<span class='warning'>\The [A] blocks you.</span>"
+			return
+
+	usr.Move(above)
+	usr << "<span class='notice'>You move upwards.</span>"
+
+/obj/item/weapon/tank/jetpack/verb/movedown()
+	set name = "Move Downwards"
+	set category = "Object"
+
+	. = 1
+	if(!allow_thrust(0.01, usr))
+		usr << "<span class='warning'>\The [src] is disabled.</span>"
+		return
+
+	var/turf/below = GetBelow(src)
+	if(!istype(below))
+		usr << "<span class='notice'>There is nothing of interest in this direction.</span>"
+		return
+
+	if(below.density)
+		usr << "<span class='warning'>You bump against \the [below].</span>"
+		return
+
+	for(var/atom/A in below)
+		if(A.density)
+			usr << "<span class='warning'>\The [A] blocks you.</span>"
+			return
+
+	usr.Move(below)
+	usr << "<span class='notice'>You move downwards.</span>"

code/modules/multiz/pipes.dm

@@ -0,0 +1,227 @@
+////////////////////////////
+// parent class for pipes //
+////////////////////////////
+obj/machinery/atmospherics/pipe/zpipe
+		icon = 'icons/obj/structures.dmi'
+		icon_state = "up"
+
+		name = "upwards pipe"
+		desc = "A pipe segment to connect upwards."
+
+		volume = 70
+
+		dir = SOUTH
+		initialize_directions = SOUTH
+
+		var/obj/machinery/atmospherics/node1	//connection on the same Z
+		var/obj/machinery/atmospherics/node2	//connection on the other Z
+
+		var/minimum_temperature_difference = 300
+		var/thermal_conductivity = 0 //WALL_HEAT_TRANSFER_COEFFICIENT No
+
+		var/maximum_pressure = 70*ONE_ATMOSPHERE
+		var/fatigue_pressure = 55*ONE_ATMOSPHERE
+		alert_pressure = 55*ONE_ATMOSPHERE
+
+
+		level = 1
+
+obj/machinery/atmospherics/pipe/zpipe/New()
+	..()
+	switch(dir)
+		if(SOUTH)
+			initialize_directions = SOUTH
+		if(NORTH)
+			initialize_directions = NORTH
+		if(WEST)
+			initialize_directions = WEST
+		if(EAST)
+			initialize_directions = EAST
+		if(NORTHEAST)
+			initialize_directions = NORTH
+		if(NORTHWEST)
+			initialize_directions = WEST
+		if(SOUTHEAST)
+			initialize_directions = EAST
+		if(SOUTHWEST)
+			initialize_directions = SOUTH
+
+/obj/machinery/atmospherics/pipe/zpipe/hide(var/i)
+	if(istype(loc, /turf/simulated))
+		invisibility = i ? 101 : 0
+	update_icon()
+
+obj/machinery/atmospherics/pipe/up/process()
+	if(!parent) //This should cut back on the overhead calling build_network thousands of times per cycle
+		..()
+	else
+		. = PROCESS_KILL
+
+obj/machinery/atmospherics/pipe/zpipe/check_pressure(pressure)
+	var/datum/gas_mixture/environment = loc.return_air()
+
+	var/pressure_difference = pressure - environment.return_pressure()
+
+	if(pressure_difference > maximum_pressure)
+		burst()
+
+	else if(pressure_difference > fatigue_pressure)
+		//TODO: leak to turf, doing pfshhhhh
+		if(prob(5))
+			burst()
+
+	else return 1
+
+obj/machinery/atmospherics/pipe/zpipe/proc/burst()
+	src.visible_message("<span class='warning'>\The [src] bursts!</span>");
+	playsound(src.loc, 'sound/effects/bang.ogg', 25, 1)
+	var/datum/effect/effect/system/smoke_spread/smoke = new
+	smoke.set_up(1,0, src.loc, 0)
+	smoke.start()
+	qdel(src) // NOT qdel.
+
+obj/machinery/atmospherics/pipe/zpipe/proc/normalize_dir()
+	if(dir==3)
+		set_dir(1)
+	else if(dir==12)
+		set_dir(4)
+
+obj/machinery/atmospherics/pipe/zpipe/Destroy()
+	if(node1)
+		node1.disconnect(src)
+	if(node2)
+		node2.disconnect(src)
+	..()
+
+obj/machinery/atmospherics/pipe/zpipe/pipeline_expansion()
+	return list(node1, node2)
+
+obj/machinery/atmospherics/pipe/zpipe/update_icon()
+	return
+
+obj/machinery/atmospherics/pipe/zpipe/disconnect(obj/machinery/atmospherics/reference)
+	if(reference == node1)
+		if(istype(node1, /obj/machinery/atmospherics/pipe))
+			qdel(parent)
+		node1 = null
+
+	if(reference == node2)
+		if(istype(node2, /obj/machinery/atmospherics/pipe))
+			qdel(parent)
+		node2 = null
+
+	return null
+/////////////////////////
+// the elusive up pipe //
+/////////////////////////
+obj/machinery/atmospherics/pipe/zpipe/up
+		icon = 'icons/obj/structures.dmi'
+		icon_state = "up"
+
+		name = "upwards pipe"
+		desc = "A pipe segment to connect upwards."
+
+obj/machinery/atmospherics/pipe/zpipe/up/initialize()
+	normalize_dir()
+	var/node1_dir
+
+	for(var/direction in cardinal)
+		if(direction&initialize_directions)
+			if (!node1_dir)
+				node1_dir = direction
+
+	for(var/obj/machinery/atmospherics/target in get_step(src,node1_dir))
+		if(target.initialize_directions & get_dir(target,src))
+			if (check_connect_types(target,src))
+				node1 = target
+				break
+
+	var/turf/above = GetAbove(src)
+	if(above)
+		for(var/obj/machinery/atmospherics/target in above)
+			if(target.initialize_directions && istype(target, /obj/machinery/atmospherics/pipe/zpipe/down))
+				if (check_connect_types(target,src))
+					node2 = target
+					break
+
+
+	var/turf/T = src.loc			// hide if turf is not intact
+	hide(!T.is_plating())
+
+///////////////////////
+// and the down pipe //
+///////////////////////
+
+obj/machinery/atmospherics/pipe/zpipe/down
+		icon = 'icons/obj/structures.dmi'
+		icon_state = "down"
+
+		name = "downwards pipe"
+		desc = "A pipe segment to connect downwards."
+
+obj/machinery/atmospherics/pipe/zpipe/down/initialize()
+	normalize_dir()
+	var/node1_dir
+
+	for(var/direction in cardinal)
+		if(direction&initialize_directions)
+			if (!node1_dir)
+				node1_dir = direction
+
+	for(var/obj/machinery/atmospherics/target in get_step(src,node1_dir))
+		if(target.initialize_directions & get_dir(target,src))
+			if (check_connect_types(target,src))
+				node1 = target
+				break
+
+	var/turf/below = GetBelow(src)
+	if(below)
+		for(var/obj/machinery/atmospherics/target in below)
+			if(target.initialize_directions && istype(target, /obj/machinery/atmospherics/pipe/zpipe/up))
+				if (check_connect_types(target,src))
+					node2 = target
+					break
+
+
+	var/turf/T = src.loc			// hide if turf is not intact
+	hide(!T.is_plating())
+
+///////////////////////
+// supply/scrubbers  //
+///////////////////////
+
+obj/machinery/atmospherics/pipe/zpipe/up/scrubbers
+	icon_state = "up-scrubbers"
+	name = "upwards scrubbers pipe"
+	desc = "A scrubbers pipe segment to connect upwards."
+	connect_types = CONNECT_TYPE_SCRUBBER
+	layer = 2.38
+	icon_connect_type = "-scrubbers"
+	color = PIPE_COLOR_RED
+
+obj/machinery/atmospherics/pipe/zpipe/up/supply
+	icon_state = "up-supply"
+	name = "upwards supply pipe"
+	desc = "A supply pipe segment to connect upwards."
+	connect_types = CONNECT_TYPE_SUPPLY
+	layer = 2.39
+	icon_connect_type = "-supply"
+	color = PIPE_COLOR_BLUE
+
+obj/machinery/atmospherics/pipe/zpipe/down/scrubbers
+	icon_state = "down-scrubbers"
+	name = "downwards scrubbers pipe"
+	desc = "A scrubbers pipe segment to connect downwards."
+	connect_types = CONNECT_TYPE_SCRUBBER
+	layer = 2.38
+	icon_connect_type = "-scrubbers"
+	color = PIPE_COLOR_RED
+
+obj/machinery/atmospherics/pipe/zpipe/down/supply
+	icon_state = "down-supply"
+	name = "downwards supply pipe"
+	desc = "A supply pipe segment to connect downwards."
+	connect_types = CONNECT_TYPE_SUPPLY
+	layer = 2.39
+	icon_connect_type = "-supply"
+	color = PIPE_COLOR_BLUE

code/modules/multiz/structures.dm

@@ -0,0 +1,86 @@
+//////////////////////////////
+//Contents: Ladders, Stairs.//
+//////////////////////////////
+
+/obj/structure/ladder
+	name = "ladder"
+	desc = "A ladder.  You can climb it up and down."
+	icon_state = "ladderdown"
+	icon = 'icons/obj/structures.dmi'
+	density = 0
+	opacity = 0
+	anchored = 1
+
+	var/obj/structure/ladder/target
+
+	initialize()
+		// the upper will connect to the lower
+		if(icon_state == "ladderup")
+			return
+
+		for(var/obj/structure/ladder/L in GetBelow(src))
+			if(L.icon_state == "ladderup")
+				target = L
+				L.target = src
+				return
+
+	Destroy()
+		if(target && icon_state == "ladderdown")
+			qdel(target)
+		return ..()
+
+	attackby(obj/item/C as obj, mob/user as mob)
+		. = ..()
+		attack_hand(user)
+		return
+
+	attack_hand(var/mob/M)
+		if(!target || !istype(target.loc, /turf))
+			M << "<span class='notice'>\The [src] is incomplete and can't be climbed.</span>"
+			return
+
+		var/turf/T = target.loc
+		for(var/atom/A in T)
+			if(A.density)
+				M << "<span class='notice'>\A [A] is blocking \the [src].</span>"
+				return
+
+		M.visible_message("<span class='notice'>\A [M] climbs [icon_state == "ladderup" ? "up" : "down"] \a [src]!</span>",
+			"You climb [icon_state == "ladderup"  ? "up" : "down"] \the [src]!",
+			"You hear the grunting and clanging of a metal ladder being used.")
+		M.Move(T)
+
+	CanPass(obj/mover, turf/source, height, airflow)
+		return airflow || !density
+
+/obj/structure/stairs
+	name = "Stairs"
+	desc = "Stairs.  You walk up and down them."
+	icon_state = "rampbottom"
+	icon = 'icons/obj/structures.dmi'
+	density = 0
+	opacity = 0
+	anchored = 1
+
+	var/obj/structure/stairs/connected
+
+	New()
+		..()
+		var/turf/above = GetAbove(src)
+		if(istype(above, /turf/space))
+			above.ChangeTurf(/turf/simulated/open)
+
+	initialize()
+		var/updown = icon_state == "rampbottom" ? UP : DOWN
+
+		var/turf/T = get_step(src, dir | updown)
+		connected = locate() in T
+		ASSERT(connected)
+
+	Uncross(var/atom/movable/M)
+		if(connected && M.dir == dir)
+			M.loc = connected.loc
+		return 1
+
+	CanPass(obj/mover, turf/source, height, airflow)
+		return airflow || !density

code/modules/multiz/turf.dm

@@ -0,0 +1,111 @@
+/turf/simulated/open
+	name = "open space"
+	icon = 'icons/turf/space.dmi'
+	icon_state = "black"
+	alpha = 16
+	layer = 0
+	density = 0
+	pathweight = 100000 //Seriously, don't try and path over this one numbnuts
+
+	var/turf/below
+	var/list/underlay_references
+	var/global/overlay_map = list()
+
+/turf/simulated/open/New()
+	. = ..()
+	ASSERT(HasBelow(z))
+	below = GetBelow(src)
+
+/turf/simulated/open/Entered(var/atom/movable/mover)
+	// only fall down in defined areas (read: areas with artificial gravitiy)
+	if(!istype(below)) //make sure that there is actually something below
+		below = GetBelow(src)
+		if(!below)
+			return
+
+	// No gravity in space, apparently.
+	var/area/area = get_area(src)
+	if(area.name == "Space")
+		return
+
+	// Prevent pipes from falling into the void... if there is a pipe to support it.
+	if(istype(mover, /obj/item/pipe) && \
+		(locate(/obj/structure/disposalpipe/up) in below) || \
+		 locate(/obj/machinery/atmospherics/pipe/zpipe/up in below))
+		return
+
+	// See if something prevents us from falling.
+	var/soft = 0
+	for(var/atom/A in below)
+		if(A.density)
+			if(!istype(A, /obj/structure/window))
+				return
+			else
+				var/obj/structure/window/W = A
+				if(W.is_fulltile())
+					return
+		// Dont break here, since we still need to be sure that it isnt blocked
+		if(istype(A, /obj/structure/stairs))
+			soft = 1
+
+	// We've made sure we can move, now.
+	mover.Move(below)
+
+	if(!soft)
+		if(!istype(mover, /mob))
+			if(istype(below, /turf/simulated/open))
+				below.visible_message("\The [mover] falls from the deck above through \the [below]!", "You hear a whoosh of displaced air.")
+			else
+				below.visible_message("\The [mover] falls from the deck above and slams into \the [below]!", "You hear something slam into the deck.")
+		else
+			var/mob/M = mover
+			if(istype(below, /turf/simulated/open))
+				below.visible_message("\The [mover] falls from the deck above through \the [below]!", "You hear a soft whoosh.[M.stat ? "" : ".. and some screaming."]")
+			else
+				M.visible_message("\The [mover] falls from the deck above and slams into \the [below]!", "You land on \the [below].", "You hear a soft whoosh and a crunch")
+
+			// Handle people getting hurt, it's funny!
+			if (istype(mover, /mob/living/carbon/human))
+				var/mob/living/carbon/human/H = mover
+				var/damage = 5
+				H.apply_damage(rand(0, damage), BRUTE, "head")
+				H.apply_damage(rand(0, damage), BRUTE, "chest")
+				H.apply_damage(rand(0, damage), BRUTE, "l_leg")
+				H.apply_damage(rand(0, damage), BRUTE, "r_leg")
+				H.apply_damage(rand(0, damage), BRUTE, "l_arm")
+				H.apply_damage(rand(0, damage), BRUTE, "r_arm")
+				H.weakened = max(H.weakened,2)
+				H.updatehealth()
+
+// override to make sure nothing is hidden
+/turf/simulated/open/levelupdate()
+	for(var/obj/O in src)
+		O.hide(0)
+
+// Straight copy from space.
+/turf/simulated/open/attackby(obj/item/C as obj, mob/user as mob)
+	if (istype(C, /obj/item/stack/rods))
+		var/obj/structure/lattice/L = locate(/obj/structure/lattice, src)
+		if(L)
+			return
+		var/obj/item/stack/rods/R = C
+		if (R.use(1))
+			user << "<span class='notice'>Constructing support lattice ...</span>"
+			playsound(src, 'sound/weapons/Genhit.ogg', 50, 1)
+			ReplaceWithLattice()
+		return
+
+	if (istype(C, /obj/item/stack/tile/floor))
+		var/obj/structure/lattice/L = locate(/obj/structure/lattice, src)
+		if(L)
+			var/obj/item/stack/tile/floor/S = C
+			if (S.get_amount() < 1)
+				return
+			qdel(L)
+			playsound(src, 'sound/weapons/Genhit.ogg', 50, 1)
+			S.use(1)
+			ChangeTurf(/turf/simulated/floor/airless)
+			return
+		else
+			user << "<span class='warning'>The plating is going to need some support.</span>"
+	return