Adds limb destroyer behavior to hostile mobs. (#19451)

* Adds limb destroyer behavior to hostile mobs. Mobs with this behavior will (usually [thanks proc/ran_zone]) attack the weakest limb of a mob until it gets dismembered

Adds ishostile() for this pretty specific situation

Behavior added to viscerators

* Generalizes the ability to dismember with an unarmed strike to living

* Gives xenos limb_destroyer at WJohn consultation

If a monkey or a human is var edited to have destroyer, that works now

fixes a potential runtime

code/modules/mob/living/carbon/alien/humanoid/humanoid.dm

@@ -3,6 +3,7 @@
 	icon_state = "alien_s"
 	pass_flags = PASSTABLE
 	butcher_results = list(/obj/item/weapon/reagent_containers/food/snacks/meat/slab/xeno = 5, /obj/item/stack/sheet/animalhide/xeno = 1)
+	limb_destroyer = 1
 	var/obj/item/r_store = null
 	var/obj/item/l_store = null
 	var/caste = ""

code/modules/mob/living/carbon/carbon_defense.dm

@@ -103,4 +103,26 @@
 						"<span class='userdanger'>[src] devours you!</span>")
 		C.forceMove(src)
 		stomach_contents.Add(C)
-		add_logs(src, C, "devoured")
+		add_logs(src, C, "devoured")
+
+/mob/living/carbon/proc/dismembering_strike(mob/living/attacker, dam_zone)
+	if(!attacker.limb_destroyer || !has_limbs)
+		return dam_zone
+	var/obj/item/bodypart/affecting
+	if(dam_zone && attacker.client)
+		affecting = get_bodypart(ran_zone(dam_zone))
+	else
+		var/list/things_to_ruin = shuffle(bodyparts.Copy())
+		for(var/B in things_to_ruin)
+			var/obj/item/bodypart/bodypart = B
+			if(bodypart.body_zone == "head" || bodypart.body_zone == "chest")
+				continue
+			if(!affecting || ((affecting.get_damage() / affecting.max_damage) < (bodypart.get_damage() / bodypart.max_damage)))
+				affecting = bodypart
+	if(affecting)
+		dam_zone = affecting.body_zone
+		if(affecting.get_damage() >= affecting.max_damage)
+			affecting.dismember()
+			return null
+		return affecting.body_zone
+	return dam_zone

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

@@ -19,7 +19,8 @@
 			playsound(loc, 'sound/weapons/slice.ogg', 25, 1, -1)
 			visible_message("<span class='danger'>[M] has slashed at [src]!</span>", \
 				"<span class='userdanger'>[M] has slashed at [src]!</span>")
-
+			if(!dismembering_strike(M, M.zone_selected)) //Dismemberment successful
+				return 1
 			apply_damage(damage, BRUTE, affecting, armor_block)
 			if (prob(30))
 				visible_message("<span class='danger'>[M] has wounded [src]!</span>", \

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

@@ -6,6 +6,9 @@
 		..() //shaking
 		return 0
 
+	if(M.limb_destroyer)
+		dismembering_strike(M, affecting.body_zone)
+
 	if(can_inject(M, 1, affecting))//Thick suits can stop monkey bites.
 		if(..()) //successful monkey bite, this handles disease contraction.
 			var/damage = rand(1, 3)

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

@@ -271,7 +271,9 @@
 		var/damage = rand(M.melee_damage_lower, M.melee_damage_upper)
 		if(check_shields(damage, "the [M.name]", null, MELEE_ATTACK, M.armour_penetration))
 			return 0
-		var/dam_zone = pick("chest", "l_hand", "r_hand", "l_leg", "r_leg")
+		var/dam_zone = dismembering_strike(M, pick("chest", "l_hand", "r_hand", "l_leg", "r_leg"))
+		if(!dam_zone) //Dismemberment successful
+			return 1
 		var/obj/item/bodypart/affecting = get_bodypart(ran_zone(dam_zone))
 		var/armor = run_armor_check(affecting, "melee", armour_penetration = M.armour_penetration)
 		apply_damage(damage, M.melee_damage_type, affecting, armor)
@@ -301,7 +303,9 @@
 		if(check_shields(damage, "the [M.name]"))
 			return 0
 
-		var/dam_zone = pick("head", "chest", "l_arm", "r_arm", "l_leg", "r_leg", "groin")
+		var/dam_zone = dismembering_strike(M, pick("head", "chest", "l_arm", "r_arm", "l_leg", "r_leg"))
+		if(!dam_zone) //Dismemberment successful
+			return 1
 
 		var/obj/item/bodypart/affecting = get_bodypart(ran_zone(dam_zone))
 		var/armor_block = run_armor_check(affecting, "melee")

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

@@ -970,6 +970,8 @@
 				H.visible_message("<span class='danger'>[M] has [atk_verb]ed [H]!</span>", \
 								"<span class='userdanger'>[M] has [atk_verb]ed [H]!</span>")
 
+				if(M.limb_destroyer)
+					H.dismembering_strike(M, affecting.body_zone)
 				H.apply_damage(damage, BRUTE, affecting, armor_block)
 				add_logs(M, H, "punched")
 				if((H.stat != DEAD) && damage >= M.dna.species.punchstunthreshold)

code/modules/mob/living/living_defines.dm

@@ -41,6 +41,8 @@
 	var/bloodcrawl = 0 //0 No blood crawling, BLOODCRAWL for bloodcrawling, BLOODCRAWL_EAT for crawling+mob devour
 	var/holder = null //The holder for blood crawling
 	var/ventcrawler = 0 //0 No vent crawling, 1 vent crawling in the nude, 2 vent crawling always
+	var/limb_destroyer = 0 //1 Sets AI behavior that allows mobs to target and dismember limbs with their basic attack.
+
 	var/floating = 0
 	var/mob_size = MOB_SIZE_HUMAN
 	var/metabolism_efficiency = 1 //more or less efficiency to metabolize helpful/harmful reagents and regulate body temperature..

code/modules/mob/living/simple_animal/hostile/hostile.dm

@@ -41,7 +41,6 @@
 	var/stat_attack = 0 //Mobs with stat_attack to 1 will attempt to attack things that are unconscious, Mobs with stat_attack set to 2 will attempt to attack the dead.
 	var/stat_exclusive = 0 //Mobs with this set to 1 will exclusively attack things defined by stat_attack, stat_attack 2 means they will only attack corpses
 	var/attack_same = 0 //Set us to 1 to allow us to attack our own faction, or 2, to only ever attack our own faction
-
 	var/AIStatus = AI_ON //The Status of our AI, can be set to AI_ON (On, usual processing), AI_IDLE (Will not process, but will return to AI_ON if an enemy comes near), AI_OFF (Off, Not processing ever)
 	var/atom/targets_from = null //all range/attack/etc. calculations should be done from this atom, defaults to the mob itself, useful for Vehicles and such
 

code/modules/mob/living/simple_animal/hostile/syndicate.dm

@@ -161,6 +161,7 @@
 	minbodytemp = 0
 	mob_size = MOB_SIZE_TINY
 	flying = 1
+	limb_destroyer = 1
 	speak_emote = list("states")
 	bubble_icon = "syndibot"
 	gold_core_spawnable = 1

code/modules/research/xenobiology/xenobiology.dm

@@ -596,7 +596,7 @@
 /obj/effect/timestop/proc/unfreeze_mob(mob/living/M)
 	M.AdjustStunned(-10, 1, 1)
 	M.anchored = 0
-	if(istype(M, /mob/living/simple_animal/hostile))
+	if(ishostile(M))
 		var/mob/living/simple_animal/hostile/H = M
 		H.AIStatus = initial(H.AIStatus)