Fixes zombies being able to use huds / zombie code refactor (#5313)

# About the pull request

Fixes zombies being able to use tech huds, applies to sec, medical and
sl huds.Fixes #4309. Also did a little refactoring for some of the
zombie code while I was at it. There is also another bug which was found
and fixed, basically whenever mobs removed their huds it still displayed
the examine text for that hud type.

# Explain why it's good for the game

my immersion is ruined when I can modify sec records as a zombie.

# Changelog

:cl:
fix: fixes the associated examine text being displayed for different hud
types even when removed.
balance: slightly increases zombie infection rate in dead mobs
refactor: refactored some zombie code. 
/:cl:

---------

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

code/datums/diseases/black_goo.dm

@@ -1,4 +1,12 @@
 //Disease Datum
+#define ZOMBIE_INFECTION_STAGE_ONE 1
+#define ZOMBIE_INFECTION_STAGE_TWO 2
+#define ZOMBIE_INFECTION_STAGE_THREE 3
+#define SLOW_INFECTION_RATE 1
+#define FAST_INFECTION_RATE 7
+#define STAGE_LEVEL_THRESHOLD 360
+#define MESSAGE_COOLDOWN_TIME 1 MINUTES
+
 /datum/disease/black_goo
 	name = "Black Goo"
 	max_stages = 3
@@ -16,117 +24,117 @@
 	longevity = 500 //the virus tend to die before the dead is turn into zombie this should fix it.
 	stage_prob = 0//no randomness
 
-	/// whether we're currently transforming the host into a zombie.
-	var/zombie_transforming = 0
-	/// tells a dead infectee their stage, so they can know when-abouts they'll revive
+	/// boolean value to determine if the mob is currently transforming into a zombie.
+	var/zombie_is_transforming = FALSE
+
+	/// variable to keep track of the stage level, used to prevent the stage message from being displayed more than once for any given stage.
 	var/stage_counter = 0
 
 //new variables to handle infection progression inside a stage.
 
-	/// variable that contain accumulated virus progression for an host.
+	/// variable that contains accumulated virus progression for a host. Iterates to a value above 360 and is then reset.
 	var/stage_level = 0
-	/// variable that handle passive increase of the virus of an host.
-	var/infection_rate = 1
 
-	///the number of stage level needed to pass another stage.
-	var/stage_level_check = 360
+	/// variable that handles passive increase of the virus of a host.
+	var/infection_rate = SLOW_INFECTION_RATE
 
-	/// cooldown between each check to see if we display a symptome idea is to get 60s between symptome atleast.
-	var/message_cooldown_time = 1 MINUTES
+	/// cooldown for the living mob's symptom messages
 	COOLDOWN_DECLARE(goo_message_cooldown)
 
 /datum/disease/black_goo/stage_act()
 	..()
-	if(!ishuman(affected_mob)) return
-	var/mob/living/carbon/human/H = affected_mob
+	if(!ishuman_strict(affected_mob))
+		return
+	var/mob/living/carbon/human/infected_mob = affected_mob
 
-	// check if your already a zombie or in the process of being transform into one...
-	if(iszombie(H))
+	if(iszombie(infected_mob))
 		return
 
-	// check if dead
-	if(H.stat == DEAD)
-		infection_rate = 4
+	// infection rate is faster for dead mobs
+	if(infected_mob.stat == DEAD)
+		infection_rate = FAST_INFECTION_RATE
 
-	// check if he isn't dead
-	if(H.stat != DEAD)
-		infection_rate = 1
+	// standard infection rate for living mobs
+	if(infected_mob.stat != DEAD)
+		infection_rate = SLOW_INFECTION_RATE
 
-	// here we add the new infection rate to the stage level.
 	stage_level += infection_rate
 
-	// we want to check if we have reach enough stage level to gain a stage 3 stage of 6 min if you get it once.
-	if(stage_level >= stage_level_check)
+	// resets the stage_level once it passes the threshold.
+	if(stage_level >= STAGE_LEVEL_THRESHOLD)
 		stage++
-		stage_level -= stage_level_check
+		stage_level = stage_level % STAGE_LEVEL_THRESHOLD
 
 	switch(stage)
-		if(1)
-			if(H.stat == DEAD && stage_counter != stage)
-				to_chat(H, SPAN_CENTERBOLD("Your zombie infection is now at stage one! Zombie transformation begins at stage three."))
+		if(ZOMBIE_INFECTION_STAGE_ONE)
+			if(infected_mob.stat == DEAD && stage_counter != stage)
+				to_chat(infected_mob, SPAN_CENTERBOLD("Your zombie infection is now at stage one! Zombie transformation begins at stage three."))
 				stage_counter = stage
 
-			if (!COOLDOWN_FINISHED(src, goo_message_cooldown))
-				return
-			COOLDOWN_START(src, goo_message_cooldown, message_cooldown_time)
-
-			switch(rand(0, 100))
-				if(0 to 25)
+			// dead mobs should not have symptoms, because... they are dead.
+			if(infected_mob.stat != DEAD)
+				if (!COOLDOWN_FINISHED(src, goo_message_cooldown))
 					return
-				if(25 to 75)
-					to_chat(affected_mob, SPAN_DANGER("You feel warm..."))
-					stage_level += 9
-				if(75 to 95)
-					to_chat(affected_mob, SPAN_DANGER("Your throat is really dry..."))
-					stage_level += 18
-				if(95 to 100)
-					to_chat(affected_mob, SPAN_DANGER("You can't trust them..."))
-					stage_level += 36
-
-		if(2)
-			if(H.stat == DEAD && stage_counter != stage)
-				to_chat(H, SPAN_CENTERBOLD("Your zombie infection is now at stage two! Zombie transformation begins at stage three."))
+				COOLDOWN_START(src, goo_message_cooldown, MESSAGE_COOLDOWN_TIME)
+
+				switch(rand(0, 100))
+					if(0 to 25)
+						return
+					if(25 to 75)
+						to_chat(infected_mob, SPAN_DANGER("You feel warm..."))
+						stage_level += 9
+					if(75 to 95)
+						to_chat(infected_mob, SPAN_DANGER("Your throat is really dry..."))
+						stage_level += 18
+					if(95 to 100)
+						to_chat(infected_mob, SPAN_DANGER("You can't trust them..."))
+						stage_level += 36
+
+		if(ZOMBIE_INFECTION_STAGE_TWO)
+			if(infected_mob.stat == DEAD && stage_counter != stage)
+				to_chat(infected_mob, SPAN_CENTERBOLD("Your zombie infection is now at stage two! Zombie transformation begins at stage three."))
 				stage_counter = stage
 
-			if (!COOLDOWN_FINISHED(src, goo_message_cooldown))
-				return
-			COOLDOWN_START(src, goo_message_cooldown, message_cooldown_time)
-
-			switch(rand(0, 100))
-				if(0 to 25)
+			if(infected_mob.stat != DEAD)
+				if (!COOLDOWN_FINISHED(src, goo_message_cooldown))
 					return
-				if(25 to 50)
-					to_chat(affected_mob, SPAN_DANGER("You can't trust them..."))
-					stage_level += 5
-				if(50 to 75)
-					to_chat(affected_mob, SPAN_DANGER("You feel really warm..."))
-					stage_level += 9
-				if(75 to 85)
-					to_chat(affected_mob, SPAN_DANGER("Your throat is really dry..."))
-					stage_level += 18
-				if(85 to 95)
-					H.vomit_on_floor()
-					stage_level += 36
-				if(95 to 100)
-					to_chat(affected_mob, SPAN_DANGER("You cough up some black fluid..."))
-					stage_level += 42
-
-		if(3)
-			//check if your already a zombie just return to avoid weird stuff... if for some weird reason first filter deoesn't work...
-			if(iszombie(H))
+				COOLDOWN_START(src, goo_message_cooldown, MESSAGE_COOLDOWN_TIME)
+
+				switch(rand(0, 100))
+					if(0 to 25)
+						return
+					if(25 to 50)
+						to_chat(infected_mob, SPAN_DANGER("You can't trust them..."))
+						stage_level += 5
+					if(50 to 75)
+						to_chat(infected_mob, SPAN_DANGER("You feel really warm..."))
+						stage_level += 9
+					if(75 to 85)
+						to_chat(infected_mob, SPAN_DANGER("Your throat is really dry..."))
+						stage_level += 18
+					if(85 to 95)
+						infected_mob.vomit_on_floor()
+						stage_level += 36
+					if(95 to 100)
+						to_chat(infected_mob, SPAN_DANGER("You cough up some black fluid..."))
+						stage_level += 42
+
+		if(ZOMBIE_INFECTION_STAGE_THREE)
+			//check if the mob is already a zombie and just return to avoid weird stuff, edge case if zombie_is_transforming deoesn't work.
+			if(iszombie(infected_mob))
 				return
 
-			if(H.stat == DEAD && stage_counter != stage)
-				to_chat(H, SPAN_CENTERBOLD("Your zombie infection is now at stage three! Zombie transformation begin!"))
+			if(infected_mob.stat == DEAD && stage_counter != stage)
+				to_chat(infected_mob, SPAN_CENTERBOLD("Your zombie infection is now at stage three! Zombie transformation begin!"))
 				stage_counter = stage
 			hidden = list(0,0)
-			if(!zombie_transforming)
-				zombie_transform(H)
-			H.next_move_slowdown = max(H.next_move_slowdown, 2)
+			if(!zombie_is_transforming)
+				zombie_transform(infected_mob)
+			infected_mob.next_move_slowdown = max(infected_mob.next_move_slowdown, 2)
 
 /datum/disease/black_goo/proc/zombie_transform(mob/living/carbon/human/human)
 	set waitfor = 0
-	zombie_transforming = TRUE
+	zombie_is_transforming = TRUE
 	human.vomit_on_floor()
 	human.adjust_effect(5, STUN)
 	sleep(20)
@@ -143,7 +151,7 @@
 		human.set_species(SPECIES_ZOMBIE)
 		stage = 3
 		human.faction = FACTION_ZOMBIE
-		zombie_transforming = FALSE
+		zombie_is_transforming = FALSE
 
 
 /obj/item/weapon/zombie_claws
@@ -298,3 +306,11 @@
 	for(var/i=1; i <= storage_slots; i++)
 		new /obj/item/reagent_container/food/drinks/bottle/black_goo(src)
 	return
+
+#undef ZOMBIE_INFECTION_STAGE_ONE
+#undef ZOMBIE_INFECTION_STAGE_TWO
+#undef ZOMBIE_INFECTION_STAGE_THREE
+#undef STAGE_LEVEL_THRESHOLD
+#undef SLOW_INFECTION_RATE
+#undef FAST_INFECTION_RATE
+#undef MESSAGE_COOLDOWN_TIME

code/datums/mob_hud.dm

@@ -33,10 +33,8 @@ GLOBAL_LIST_INIT_TYPED(huds, /datum/mob_hud, list(
 /datum/mob_hud/proc/remove_hud_from(mob/user, source)
 	if(length(hudusers[user]) && (source in hudusers[user]))
 		hudusers[user] -= source
-
 	if(length(hudusers[user]))
 		return FALSE
-
 	for(var/mob/target in hudmobs)
 		remove_from_single_hud(user, target)
 

code/modules/mob/living/carbon/human/examine.dm

@@ -528,24 +528,24 @@
 	if(istype(passed_mob, /mob/living/carbon/human))
 		var/mob/living/carbon/human/passed_human = passed_mob
 		if (issynth(passed_human))
-			return 1
+			return TRUE
 		switch(hudtype)
 			if("security")
 				if(skillcheck(passed_human, SKILL_POLICE, SKILL_POLICE_SKILLED))
 					var/datum/mob_hud/sec_hud = GLOB.huds[MOB_HUD_SECURITY_ADVANCED]
-					if(locate(passed_mob) in sec_hud.hudusers)
+					if(sec_hud.hudusers[passed_human])
 						return TRUE
 			if("medical")
 				if(skillcheck(passed_human, SKILL_MEDICAL, SKILL_MEDICAL_MEDIC))
 					var/datum/mob_hud/med_hud = GLOB.huds[MOB_HUD_MEDICAL_ADVANCED]
-					if(locate(passed_mob) in med_hud.hudusers)
+					if(med_hud.hudusers[passed_human])
 						return TRUE
 			if("squadleader")
 				var/datum/mob_hud/faction_hud = GLOB.huds[MOB_HUD_FACTION_USCM]
-				if(passed_human.mind && passed_human.assigned_squad && passed_human.assigned_squad.squad_leader == passed_human && locate(passed_mob) in faction_hud.hudusers)
+				if(passed_human.mind && passed_human.assigned_squad && passed_human.assigned_squad.squad_leader == passed_human && faction_hud.hudusers[passed_mob])
 					return TRUE
 			else
-				return 0
+				return FALSE
 	else if(isrobot(passed_mob))
 		var/mob/living/silicon/robot/R = passed_mob
 		switch(hudtype)
@@ -554,6 +554,6 @@
 			if("medical")
 				return istype(R.module_state_1, /obj/item/robot/sight/hud/med) || istype(R.module_state_2, /obj/item/robot/sight/hud/med) || istype(R.module_state_3, /obj/item/robot/sight/hud/med)
 			else
-				return 0
+				return FALSE
 	else
-		return 0
+		return FALSE

code/modules/mob/living/carbon/human/species/zombie.dm

@@ -59,17 +59,18 @@
 	zombie.equip_to_slot_or_del(new /obj/item/weapon/zombie_claws(zombie), WEAR_L_HAND, TRUE)
 	zombie.equip_to_slot_or_del(new /obj/item/clothing/glasses/zombie_eyes(zombie), WEAR_EYES, TRUE)
 
-	var/datum/disease/black_goo/D = locate() in zombie.viruses
-	if(!D)
-		D = zombie.AddDisease(new /datum/disease/black_goo())
-	D.stage = 5
+	var/datum/disease/black_goo/zombie_infection = locate() in zombie.viruses
+	if(!zombie_infection)
+		zombie_infection = zombie.AddDisease(new /datum/disease/black_goo())
+	zombie_infection.stage = 3
 
 	var/datum/mob_hud/Hu = GLOB.huds[MOB_HUD_MEDICAL_OBSERVER]
 	Hu.add_hud_to(zombie, zombie)
 
 	return ..()
 
 
+
 /datum/species/zombie/post_species_loss(mob/living/carbon/human/zombie)
 	..()
 	remove_from_revive(zombie)