Refactor ladders so that they actually work (#32797)

code/game/objects/structures/ladders.dm

@@ -1,48 +1,55 @@
+// Basic ladder. By default links to the z-level above/below.
 /obj/structure/ladder
 	name = "ladder"
 	desc = "A sturdy metal ladder."
 	icon = 'icons/obj/structures.dmi'
 	icon_state = "ladder11"
-	var/id = null
+	anchored = TRUE
-	var/height = 0							//the 'height' of the ladder. higher numbers are considered physically higher
+	var/obj/structure/ladder/down   //the ladder below this one
-	var/obj/structure/ladder/down = null	//the ladder below this one
+	var/obj/structure/ladder/up     //the ladder above this one
-	var/obj/structure/ladder/up = null		//the ladder above this one
-	var/auto_connect = FALSE
 
-/obj/structure/ladder/unbreakable //mostly useful for awaymissions to prevent halting progress in a mission
+/obj/structure/ladder/Initialize(mapload, obj/structure/ladder/up, obj/structure/ladder/down)
-	name = "sturdy ladder"
-	desc = "An extremely sturdy metal ladder."
-
-
-/obj/structure/ladder/Initialize(mapload)
-	GLOB.ladders += src
 	..()
+	if (up)
+		src.up = up
+		up.down = src
+		up.update_icon()
+	if (down)
+		src.down = down
+		down.up = src
+		down.update_icon()
 	return INITIALIZE_HINT_LATELOAD
 
-/obj/structure/ladder/Destroy()
+/obj/structure/ladder/Destroy(force)
+	if ((resistance_flags & INDESTRUCTIBLE) && !force)
+		return QDEL_HINT_LETMELIVE
+
 	if(up && up.down == src)
 		up.down = null
 		up.update_icon()
 	if(down && down.up == src)
 		down.up = null
 		down.update_icon()
-	GLOB.ladders -= src
+	return ..()
-	. = ..()
 
 /obj/structure/ladder/LateInitialize()
-	for(var/obj/structure/ladder/L in GLOB.ladders)
+	// By default, discover ladders above and below us vertically
-		if(L.id == id || (auto_connect && L.auto_connect && L.x == x && L.y == y))
+	var/turf/T = get_turf(src)
-			if(L.height == (height - 1))
-				down = L
-				continue
-			if(L.height == (height + 1))
-				up = L
-				continue
 
-		if(up && down)	//if both our connections are filled
+	if (!down)
+		for (var/obj/structure/ladder/L in locate(T.x, T.y, T.z - 1))
+			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))
+			up = L
+			L.down = src  // Don't waste effort looping the other way
+			L.update_icon()
 			break
-	update_icon()
 
+	update_icon()
 
 /obj/structure/ladder/update_icon()
 	if(up && down)
@@ -57,23 +64,34 @@
 	else	//wtf make your ladders properly assholes
 		icon_state = "ladder00"
 
+/obj/structure/ladder/singularity_pull()
+	if (!(resistance_flags & INDESTRUCTIBLE))
+		visible_message("<span class='danger'>[src] is torn to pieces by the gravitational pull!</span>")
+		qdel(src)
+
 /obj/structure/ladder/proc/travel(going_up, mob/user, is_ghost, obj/structure/ladder/ladder)
 	if(!is_ghost)
-		show_fluff_message(going_up,user)
+		show_fluff_message(going_up, user)
 		ladder.add_fingerprint(user)
 
+	var/turf/T = get_turf(ladder)
 	var/atom/movable/AM
 	if(user.pulling)
 		AM = user.pulling
-		user.pulling.forceMove(get_turf(ladder))
+		AM.forceMove(T)
-	user.forceMove(get_turf(ladder))
+	user.forceMove(T)
 	if(AM)
 		user.start_pulling(AM)
 
+/obj/structure/ladder/proc/use(mob/user, is_ghost=FALSE)
+	if (!is_ghost && !in_range(src, user))
+		return
 
-/obj/structure/ladder/proc/use(mob/user,is_ghost=0)
+	if (up && down)
-	if(up && down)
+		var/result = alert("Go up or down [src]?", "Ladder", "Up", "Down", "Cancel")
-		switch( alert("Go up or down the ladder?", "Ladder", "Up", "Down", "Cancel") )
+		if (!is_ghost && !in_range(src, user))
+			return  // nice try
+		switch(result)
 			if("Up")
 				travel(TRUE, user, is_ghost, up)
 			if("Down")
@@ -83,7 +101,7 @@
 	else if(up)
 		travel(TRUE, user, is_ghost, up)
 	else if(down)
-		travel(FALSE, user,is_ghost, down)
+		travel(FALSE, user, is_ghost, down)
 	else
 		to_chat(user, "<span class='warning'>[src] doesn't seem to lead anywhere!</span>")
 
@@ -91,44 +109,66 @@
 		add_fingerprint(user)
 
 /obj/structure/ladder/attack_hand(mob/user)
-	if(can_use(user))
+	use(user)
-		use(user)
 
 /obj/structure/ladder/attack_paw(mob/user)
-	return attack_hand(user)
+	return use(user)
 
 /obj/structure/ladder/attackby(obj/item/W, mob/user, params)
-	return attack_hand(user)
+	return use(user)
 
 /obj/structure/ladder/attack_robot(mob/living/silicon/robot/R)
 	if(R.Adjacent(src))
-		return attack_hand(R)
+		return use(R)
 
 /obj/structure/ladder/attack_ghost(mob/dead/observer/user)
-	use(user,1)
+	use(user, TRUE)
 
-/obj/structure/ladder/proc/show_fluff_message(up,mob/user)
+/obj/structure/ladder/proc/show_fluff_message(going_up, mob/user)
-	if(up)
+	if(going_up)
-		user.visible_message("[user] climbs up \the [src].","<span class='notice'>You climb up \the [src].</span>")
+		user.visible_message("[user] climbs up [src].","<span class='notice'>You climb up [src].</span>")
 	else
-		user.visible_message("[user] climbs down \the [src].","<span class='notice'>You climb down \the [src].</span>")
+		user.visible_message("[user] climbs down [src].","<span class='notice'>You climb down [src].</span>")
-
-/obj/structure/ladder/proc/can_use(mob/user)
-	return 1
-
-/obj/structure/ladder/unbreakable/Destroy(force)
-	if(force)
-		. = ..()
-	else
-		return QDEL_HINT_LETMELIVE
-
-/obj/structure/ladder/unbreakable/singularity_pull()
-	return
-
-/obj/structure/ladder/auto_connect //They will connect to ladders with the same X and Y without needing to share an ID
-	auto_connect = TRUE
 
 
-/obj/structure/ladder/singularity_pull()
+// Indestructible away mission ladders which link based on a mapped ID and height value rather than X/Y/Z.
-	visible_message("<span class='danger'>[src] is torn to pieces by the gravitational pull!</span>")
+/obj/structure/ladder/unbreakable
-	qdel(src)
+	name = "sturdy ladder"
+	desc = "An extremely sturdy metal ladder."
+	resistance_flags = INDESTRUCTIBLE
+	var/id
+	var/height = 0  // higher numbers are considered physically higher
+
+/obj/structure/ladder/unbreakable/Initialize()
+	GLOB.ladders += src
+	return ..()
+
+/obj/structure/ladder/unbreakable/Destroy()
+	. = ..()
+	if (. != QDEL_HINT_LETMELIVE)
+		GLOB.ladders -= src
+
+/obj/structure/ladder/unbreakable/LateInitialize()
+	// Override the parent to find ladders based on being height-linked
+	if (!id || (up && down))
+		update_icon()
+		return
+
+	for (var/O in GLOB.ladders)
+		var/obj/structure/ladder/unbreakable/L = O
+		if (L.id != id)
+			continue  // not one of our pals
+		if (!down && L.height == height - 1)
+			down = L
+			L.up = src
+			L.update_icon()
+			if (up)
+				break  // break if both our connections are filled
+		else if (!up && L.height == height + 1)
+			up = L
+			L.down = src
+			L.update_icon()
+			if (down)
+				break  // break if both our connections are filled
+
+	update_icon()

code/modules/awaymissions/mission_code/Academy.dm

@@ -335,7 +335,7 @@
 			target_mob.Move(T)
 
 /obj/structure/ladder/unbreakable/rune
-	name = "Teleportation Rune"
+	name = "\improper Teleportation Rune"
 	desc = "Could lead anywhere."
 	icon = 'icons/obj/rune.dmi'
 	icon_state = "1"
@@ -347,7 +347,6 @@
 /obj/structure/ladder/unbreakable/rune/show_fluff_message(up,mob/user)
 	user.visible_message("[user] activates \the [src].","<span class='notice'>You activate \the [src].</span>")
 
-/obj/structure/ladder/can_use(mob/user)
+/obj/structure/ladder/unbreakable/rune/use(mob/user, is_ghost=FALSE)
-	if(user.mind in SSticker.mode.wizards)
+	if(is_ghost || !(user.mind in SSticker.mode.wizards))
-		return 0
+		..()
-	return 1

code/modules/mining/lavaland/necropolis_chests.dm

@@ -578,17 +578,18 @@
 	var/ladder_x = T.x
 	var/ladder_y = T.y
 	to_chat(user, "<span class='notice'>You unfold the ladder. It extends much farther than you were expecting.</span>")
+	var/last_ladder = null
 	for(var/i in 1 to world.maxz)
-		if(i == ZLEVEL_CENTCOM || i == ZLEVEL_TRANSIT)
+		if(i == ZLEVEL_CENTCOM || i == ZLEVEL_TRANSIT || i == ZLEVEL_CITYOFCOGS)
 			continue
 		var/turf/T2 = locate(ladder_x, ladder_y, i)
-		new /obj/structure/ladder/unbreakable/jacob(T2)
+		last_ladder = new /obj/structure/ladder/unbreakable/jacob(T2, null, last_ladder)
 	qdel(src)
 
+// Inherit from unbreakable but don't set ID, to suppress the default Z linkage
 /obj/structure/ladder/unbreakable/jacob
 	name = "jacob's ladder"
 	desc = "An indestructible celestial ladder that violates the laws of physics."
-	auto_connect = TRUE
 
 ///Bosses