Add look up verb for multi-z (tgstation#50782)

* Add look up verb

* Made requested changes

* Added a toggle

* Removed redundant arg from signal

* Update code/modules/mob/living/living.dm

Co-authored-by: Rohesie <[email protected]>

* Update code/modules/mob/living/living.dm

Co-authored-by: Rohesie <[email protected]>

* Adds keybinding description

* Removed unused signal

Co-authored-by: Rohesie <[email protected]>

code/__DEFINES/combat.dm

@@ -57,6 +57,7 @@
 #define CLICK_CD_HANDCUFFED 10
 #define CLICK_CD_RESIST 20
 #define CLICK_CD_GRABBING 10
+#define CLICK_CD_LOOK_UP 5
 
 //Cuff resist speeds
 #define FAST_CUFFBREAK 1

code/__DEFINES/dcs/signals.dm

@@ -214,6 +214,7 @@
 
 // /mob/living signals
 #define COMSIG_LIVING_RESIST "living_resist"					//from base of mob/living/resist() (/mob/living)
+#define COMSIG_LIVING_LOOK_UP "living_look_up"					//from base of mob/living/look_up() (/mob/living)
 #define COMSIG_LIVING_IGNITED "living_ignite"					//from base of mob/living/IgniteMob() (/mob/living)
 #define COMSIG_LIVING_EXTINGUISHED "living_extinguished"		//from base of mob/living/ExtinguishMob() (/mob/living)
 #define COMSIG_LIVING_ELECTROCUTE_ACT "living_electrocute_act"		//from base of mob/living/electrocute_act(): (shock_damage, source, siemens_coeff, flags)

code/__DEFINES/is_helpers.dm

@@ -41,6 +41,8 @@ GLOBAL_LIST_INIT(turfs_without_ground, typecacheof(list(
 
 #define isplatingturf(A) (istype(A, /turf/open/floor/plating))
 
+#define isopenspace(A) (istype(A, /turf/open/openspace))
+
 //Mobs
 #define isliving(A) (istype(A, /mob/living))
 

code/datums/keybinding/living.dm

@@ -15,3 +15,19 @@
 	var/mob/living/L = user.mob
 	L.resist()
 	return TRUE
+
+/datum/keybinding/living/look_up
+	hotkey_keys = list("L")
+	name = "look up"
+	full_name = "Look Up"
+	description = "Look up at the next z-level.  Only works if directly below open space."
+
+/datum/keybinding/living/look_up/down(client/user)
+	var/mob/living/L = user.mob
+	L.look_up()
+	return TRUE
+
+/datum/keybinding/living/look_up/up(client/user)
+	var/mob/living/L = user.mob
+	L.stop_look_up()
+	return TRUE

code/modules/mob/living/living.dm

@@ -1495,3 +1495,36 @@
 	if(!apply_change)
 		return BODYTEMP_NORMAL
 	return BODYTEMP_NORMAL + get_body_temp_normal_change()
+
+///Checks if the user is incapacitated or on cooldown.
+/mob/living/proc/can_look_up()
+	return !((next_move > world.time) || incapacitated(ignore_restraints = TRUE))
+
+/**
+ * look_up Changes the perspective of the mob to any openspace turf above the mob
+ *
+ * This also checks if an openspace turf is above the mob before looking up or resets the perspective if already looking up
+ *
+ */
+/mob/living/proc/look_up()
+
+	if(client.perspective != MOB_PERSPECTIVE) //We are already looking up.
+		stop_look_up()
+		return
+	if(!can_look_up())
+		return
+	var/turf/ceiling = get_step_multiz(src, UP)
+	if(!ceiling) //We are at the highest z-level.
+		to_chat(src, "<span class='warning'>You can't see through the ceiling above you.</span>")
+		return
+	else if(!isopenspace(ceiling)) //There is no openspace turf above us.
+		to_chat(src, "<span class='warning'>You can't see through the floor above you.</span>")
+		return
+
+	changeNext_move(CLICK_CD_LOOK_UP)
+	reset_perspective(ceiling)
+	RegisterSignal(src, COMSIG_MOVABLE_PRE_MOVE, .proc/stop_look_up) //We stop looking up if we move.
+
+/mob/living/proc/stop_look_up()
+	reset_perspective()
+	UnregisterSignal(src, COMSIG_MOVABLE_PRE_MOVE)