twirl knife to flick off the blood

_std/defines/component_defines/component_defines_atom.dm

@@ -50,6 +50,8 @@
 	#define COMSIG_ATOM_SET_OPACITY "atom_set_opacity"
 	/// get radioactivity level of atom (0 if signal not registered - ie, has no radioactive component) (return_val as a list)
 	#define COMSIG_ATOM_RADIOACTIVITY "atom_get_radioactivity"
+	/// when this atom has clean_forensic called, send this signal.
+	#define COMSIG_ATOM_CLEANED "atom_cleaned"
 
 // ---- minimap ----
 
@@ -151,6 +153,8 @@
 	#define COMSIG_ITEM_PROCESS "itm_process"
 	/// After attacking any atom (not just mob) with this item (item, atom/target, mob/user, reach, params)
 	#define COMSIG_ITEM_AFTERATTACK "itm_afterattack"
+	/// When the item in hand is twirl emoted and spun in hand. (user, item)
+	#define COMSIG_ITEM_TWIRLED "itm_twirled"
 
 	// ---- bomb assembly signals ----
 

code/datums/components/bloodflick.dm

@@ -0,0 +1,74 @@
+TYPEINFO(/datum/component/bloodflick)
+	initialization_args = list()
+
+/// a component that makes items flick blood off them and onto the ground when twirled.
+/datum/component/bloodflick
+	/// is the blood on the parent dried? if so, can't be cleaned by flicking.
+	var/hasdry = FALSE
+	/// Can blood be flicked off?
+	var/haswet = FALSE
+	/// a counter. represents how many sets of wet blood are on the parent
+	var/iswet = 0
+	/// how long the blood takes to dry.
+	var/drytime = 30 SECONDS
+	/// typecasted parent
+	var/obj/item/weapon
+
+/datum/component/bloodflick/Initialize()
+	if (!isitem(src.parent))
+		return COMPONENT_INCOMPATIBLE
+	src.weapon = src.parent
+	RegisterSignal(parent, COMSIG_ITEM_TWIRLED, PROC_REF(flickblood))
+	RegisterSignal(parent, COMSIG_ITEM_ATTACK_POST, PROC_REF(wetten))
+	RegisterSignal(parent, COMSIG_ATOM_CLEANED, PROC_REF(clean))
+	..()
+
+/datum/component/bloodflick/UnregisterFromParent()
+	UnregisterSignal(parent, COMSIG_ITEM_TWIRLED)
+	UnregisterSignal(parent, COMSIG_ITEM_ATTACK_POST)
+	UnregisterSignal(parent, COMSIG_ATOM_CLEANED)
+	..()
+
+/datum/component/bloodflick/proc/flickblood()
+	if (!src.weapon.blood_DNA)
+		return
+	// if all the blood is wet, flicking it off cleans it.
+	if (!src.hasdry)
+		src.weapon.clean_forensic()
+	// if there's wet blood on it, flick it off
+	if (src.haswet)
+		src.haswet = FALSE
+		make_cleanable(/obj/decal/cleanable/blood, get_turf(src.parent))
+		playsound(src.weapon.loc, 'sound/impact_sounds/Slimy_Splat_1.ogg', 40, 1)
+		SPAWN(1 DECI SECOND) // so that the twirl emote message appears first (in theory)
+			boutput("<span class='notice'>Blood splatters onto the floor!</span>") 
+
+/// applies wet blood to the knife and starts the blood drying countdown
+/datum/component/bloodflick/proc/wetten()
+	var/obj/item/dummy = src.parent
+	if (!dummy.blood_DNA) // not all attacks leave blood on the parent
+		return
+	if (!src.haswet)
+		src.haswet = TRUE
+		src.iswet += 1
+	SPAWN(drytime)
+		// it could get cleaned while it's drying
+		if (!dummy.blood_DNA)
+			src.hasdry = FALSE
+			src.haswet = FALSE
+			src.iswet = 0
+			// just in case
+			return
+		// if the parent is wet, dry it
+		if (src.haswet)
+			src.hasdry = TRUE
+			src.iswet -= 1
+		// if there's no more lingering sets of wet blood waiting to dry, dry the parent
+		if (!src.iswet)
+			src.haswet = FALSE
+
+/// resets the variables
+/datum/component/bloodflick/proc/clean()
+	src.hasdry = FALSE
+	src.haswet = FALSE
+	src.iswet = 0

code/mob/living/carbon/human/procs/emote.dm

@@ -659,6 +659,7 @@
 							else if (src.r_hand)
 								thing = src.r_hand
 						if (thing)
+							SEND_SIGNAL(thing, COMSIG_ITEM_TWIRLED, src, thing)
 							message = thing.on_spin_emote(src)
 							maptext_out = "<I>twirls [thing]</I>"
 							animate_spin(thing, prob(50) ? "L" : "R", 1, 0)

code/modules/forensics/atom_forensic.dm

@@ -254,6 +254,7 @@
 			L.forensics_blood_color = null
 			L.tracked_blood = null
 			L.set_clothing_icon_dirty()
+	SEND_SIGNAL(src, COMSIG_ATOM_CLEANED)
 
 /atom/movable/proc/track_blood()
 	return

code/obj/item/kitchen.dm

@@ -168,6 +168,7 @@ TRAYS
 
 	New()
 		..()
+		src.AddComponent(/datum/component/bloodflick)
 		src.setItemSpecial(/datum/item_special/double)
 
 	attack(mob/living/carbon/M, mob/living/carbon/user)

code/obj/item/misc_weapons.dm

@@ -796,6 +796,7 @@ TYPEINFO(/obj/item/sword/pink/angel)
 
 /obj/item/knife/butcher/New()
 	..()
+	src.AddComponent(/datum/component/bloodflick)
 	BLOCK_SETUP(BLOCK_KNIFE)
 
 /obj/item/knife/butcher/throw_impact(atom/A, datum/thrown_thing/thr)
@@ -1122,6 +1123,10 @@ TYPEINFO(/obj/item/bat)
 	var/midair_fruit_slice_stamina_cost = 7 //! The amount of stamina it costs to slice food midair
 	custom_suicide = 1
 
+/obj/item/swords/New()
+	src.AddComponent(/datum/component/bloodflick)
+	..()
+
 /obj/item/swords/proc/handle_parry(mob/target, mob/user)
 	if (target != user && ishuman(target))
 		var/mob/living/carbon/human/H = target
@@ -1707,6 +1712,7 @@ obj/item/whetstone
 	New()
 		..()
 		START_TRACKING_CAT(TR_CAT_NUKE_OP_STYLE)
+		src.AddComponent(/datum/component/bloodflick)
 		src.setItemSpecial(/datum/item_special/swipe)
 		src.update_special_color()
 		AddComponent(/datum/component/itemblock/saberblock, null, PROC_REF(get_reflect_color))

goonstation.dme

@@ -190,6 +190,7 @@ var/datum/preMapLoad/preMapLoad = new
 #include "code\datums\components\baseball_bat_reflect.dm"
 #include "code\datums\components\battleroyale_death.dm"
 #include "code\datums\components\biodegradable.dm"
+#include "code\datums\components\bloodflick.dm"
 #include "code\datums\components\buildableturf.dm"
 #include "code\datums\components\bullet_holes.dm"
 #include "code\datums\components\cell_holder.dm"