Makes showers wash away touching reagents

Also moves reagent permeability to it's own proc, and makes splash_mob respect copy

code/game/objects/structures/watercloset.dm

@@ -225,6 +225,12 @@
 		if(M.back)
 			if(M.back.clean_blood())
 				M.update_inv_back(0)
+		
+		//flush away reagents on the skin
+		if(M.touching)
+			var/remove_amount = M.touching.maximum_volume * M.reagent_permeability() //take off your suit first
+			M.touching.remove_any(remove_amount)
+		
 		if(ishuman(M))
 			var/mob/living/carbon/human/H = M
 			var/washgloves = 1

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

@@ -444,4 +444,41 @@ emp_act
 	if(!istype(wear_suit,/obj/item/clothing/suit/space)) return
 	var/obj/item/clothing/suit/space/SS = wear_suit
 	var/penetrated_dam = max(0,(damage - SS.breach_threshold))
-	if(penetrated_dam) SS.create_breaches(damtype, penetrated_dam)
+	if(penetrated_dam) SS.create_breaches(damtype, penetrated_dam)
+
+/mob/living/human/reagent_permeability()
+	var/perm = 0
+	
+	var/list/perm_by_part = list(
+		"head" = THERMAL_PROTECTION_HEAD, 
+		"upper_torso" = THERMAL_PROTECTION_UPPER_TORSO, 
+		"lower_torso" = THERMAL_PROTECTION_LOWER_TORSO, 
+		"legs" = THERMAL_PROTECTION_LEG_LEFT + THERMAL_PROTECTION_LEG_RIGHT, 
+		"feet" = THERMAL_PROTECTION_FOOT_LEFT + THERMAL_PROTECTION_FOOT_RIGHT, 
+		"arms" = THERMAL_PROTECTION_ARM_LEFT + THERMAL_PROTECTION_ARM_RIGHT, 
+		"hands" = THERMAL_PROTECTION_HAND_LEFT + THERMAL_PROTECTION_HAND_RIGHT
+		)
+	
+	for(var/obj/item/clothing/C in src.get_equipped_items())
+		if(C.permeability_coefficient == 1 || !C.body_parts_covered)
+			continue
+		if(C.body_parts_covered & HEAD)
+			perm_by_part["head"] *= C.permeability_coefficient
+		if(C.body_parts_covered & UPPER_TORSO)
+			perm_by_part["upper_torso"] *= C.permeability_coefficient
+		if(C.body_parts_covered & LOWER_TORSO)
+			perm_by_part["lower_torso"] *= C.permeability_coefficient
+		if(C.body_parts_covered & LEGS)
+			perm_by_part["legs"] *= C.permeability_coefficient
+		if(C.body_parts_covered & FEET)
+			perm_by_part["feet"] *= C.permeability_coefficient
+		if(C.body_parts_covered & ARMS)
+			perm_by_part["arms"] *= C.permeability_coefficient
+		if(C.body_parts_covered & HANDS)
+			perm_by_part["hands"] *= C.permeability_coefficient
+	
+	for(var/part in perm_by_part)
+		perm += perm_by_part[part]
+	
+	return perm
+

code/modules/mob/living/living_defense.dm

@@ -247,3 +247,6 @@
 	//Scale quadratically so that single digit numbers of fire stacks don't burn ridiculously hot.
 	//lower limit of 700 K, same as matches and roughly the temperature of a cool flame. 
 	return max(2.25*round(FIRESUIT_MAX_HEAT_PROTECTION_TEMPERATURE*(fire_stacks/FIRE_MAX_FIRESUIT_STACKS)**2), 700)
+
+/mob/living/proc/reagent_permeability()
+	return 1

code/modules/reagents/Chemistry-Holder.dm

@@ -296,9 +296,7 @@
 	touch(target) //First, handle mere touch effects
 
 	if(ismob(target))
-		//warning("[my_atom] is trying to transfer reagents to [target], which is a mob, using trans_to()")
-		//return trans_to_mob(target, amount, multiplier, copy)
-		return splash_mob(target, amount)
+		return splash_mob(target, amount, copy)
 	if(isturf(target))
 		return trans_to_turf(target, amount, multiplier, copy)
 	if(isobj(target))
@@ -369,41 +367,12 @@
 // Attempts to place a reagent on the mob's skin.
 // Reagents are not guaranteed to transfer to the target.
 // Do not call this directly, call trans_to() instead.
-/datum/reagents/proc/splash_mob(var/mob/target, var/amount = 1, var/clothes = 1)
-	var/perm = 0
-	
-	//this all seems very human-specific
-	var/list/L = list(
-		"head" = THERMAL_PROTECTION_HEAD, 
-		"upper_torso" = THERMAL_PROTECTION_UPPER_TORSO, 
-		"lower_torso" = THERMAL_PROTECTION_LOWER_TORSO, 
-		"legs" = THERMAL_PROTECTION_LEG_LEFT + THERMAL_PROTECTION_LEG_RIGHT, 
-		"feet" = THERMAL_PROTECTION_FOOT_LEFT + THERMAL_PROTECTION_FOOT_RIGHT, 
-		"arms" = THERMAL_PROTECTION_ARM_LEFT + THERMAL_PROTECTION_ARM_RIGHT, 
-		"hands" = THERMAL_PROTECTION_HAND_LEFT + THERMAL_PROTECTION_HAND_RIGHT
-		)
-	
-	if(clothes)
-		for(var/obj/item/clothing/C in target.get_equipped_items())
-			if(C.permeability_coefficient == 1 || C.body_parts_covered == 0)
-				continue
-			if(C.body_parts_covered & HEAD)
-				L["head"] *= C.permeability_coefficient
-			if(C.body_parts_covered & UPPER_TORSO)
-				L["upper_torso"] *= C.permeability_coefficient
-			if(C.body_parts_covered & LOWER_TORSO)
-				L["lower_torso"] *= C.permeability_coefficient
-			if(C.body_parts_covered & LEGS)
-				L["legs"] *= C.permeability_coefficient
-			if(C.body_parts_covered & FEET)
-				L["feet"] *= C.permeability_coefficient
-			if(C.body_parts_covered & ARMS)
-				L["arms"] *= C.permeability_coefficient
-			if(C.body_parts_covered & HANDS)
-				L["hands"] *= C.permeability_coefficient
-	for(var/t in L)
-		perm += L[t]
-	return trans_to_mob(target, amount, CHEM_TOUCH, perm)
+/datum/reagents/proc/splash_mob(var/mob/target, var/amount = 1, var/copy = 0)
+	var/perm = 1
+	if(isliving(target)) //will we ever even need to tranfer reagents to non-living mobs?
+		var/mob/living/L = target
+		perm = L.reagent_permeability()
+	return trans_to_mob(target, amount, CHEM_TOUCH, perm, copy)
 
 /datum/reagents/proc/trans_to_mob(var/mob/target, var/amount = 1, var/type = CHEM_BLOOD, var/multiplier = 1, var/copy = 0) // Transfer after checking into which holder...
 	if(!target || !istype(target))

code/modules/reagents/Chemistry-Metabolism.dm

@@ -0,0 +1,17 @@
+/datum/reagents/metabolism
+	var/metabolism_type
+
+/datum/reagents/metabolism/New(var/max = 100, var/met_type, mob/living/carbon/parent_mob)
+	..()
+	metabolism_type = met_type
+	my_atom = parent_mob
+
+/datum/reagents/proc/metabolize(var/alien)
+	if(!iscarbon(my_atom))
+		return
+	var/mob/living/carbon/C = my_atom
+	if(!C || !istype(C))
+		return
+	for(var/datum/reagent/current in reagent_list)
+		current.on_mob_life(C, alien, metabolism_type)
+	update_total()