Merge pull request #4302 from Citadel-Station-13/upstream-merge-33280

[MIRROR] Add caltrop component for spikey floor objects

code/datums/components/caltrop.dm

@@ -0,0 +1,60 @@
+/datum/component/caltrop
+	var/min_damage
+	var/max_damage
+	var/probability
+	var/flags
+
+	var/cooldown = 0
+
+/datum/component/caltrop/Initialize(_min_damage = 0, _max_damage = 0, _probability = 100,  _flags = NONE)
+	min_damage = _min_damage
+	max_damage = max(_min_damage, _max_damage)
+	probability = _probability
+	flags = _flags
+
+	RegisterSignal(list(COMSIG_MOVABLE_CROSSED), .proc/Crossed)
+
+/datum/component/caltrop/proc/Crossed(atom/movable/AM)
+	var/atom/A = parent
+	if(!A.has_gravity())
+		return
+
+	if(!prob(probability))
+		return
+
+	if(ishuman(AM))
+		var/mob/living/carbon/human/H = AM
+		if(PIERCEIMMUNE in H.dna.species.species_traits)
+			return
+
+		if((flags & CALTROP_IGNORE_WALKERS) && H.m_intent == MOVE_INTENT_WALK)
+			return
+
+		var/picked_def_zone = pick("l_leg", "r_leg")
+		var/obj/item/bodypart/O = H.get_bodypart(picked_def_zone)
+		if(!istype(O))
+			return
+		if(O.status == BODYPART_ROBOTIC)
+			return
+
+		var/feetCover = (H.wear_suit && (H.wear_suit.body_parts_covered & FEET)) || (H.w_uniform && (H.w_uniform.body_parts_covered & FEET))
+
+		if(!(flags & CALTROP_BYPASS_SHOES) && (H.shoes || feetCover))
+			return
+
+		if((H.movement_type & FLYING) || H.buckled)
+			return
+
+		var/damage = rand(min_damage, max_damage)
+		H.apply_damage(damage, BRUTE, picked_def_zone)
+
+		if(cooldown < world.time - 10) //cooldown to avoid message spam.
+			if(!H.incapacitated(ignore_restraints = TRUE))
+				H.visible_message("<span class='danger'>[H] steps on [A].</span>", \
+						"<span class='userdanger'>You step on [A]!</span>")
+			else
+				H.visible_message("<span class='danger'>[H] slides on [A]!</span>", \
+						"<span class='userdanger'>You slide on [A]!</span>")
+
+			cooldown = world.time
+		H.Knockdown(60)