[MIRROR] Motion tracker subsystem (#10232)

Co-authored-by: Cameron Lennox <killer65311@gmail.com>
Co-authored-by: Kashargul <144968721+Kashargul@users.noreply.github.com>

code/game/objects/effects/mines.dm

@@ -141,6 +141,7 @@
 		domutcheck(M,null)
 		M.UpdateAppearance()
 	visible_message("\The [src.name] flashes violently before disintegrating!")
+	SSmotiontracker.ping(src,100)
 	spawn(0)
 		qdel(s)
 		qdel(src)
@@ -158,6 +159,7 @@
 	if(istype(M))
 		M.Stun(30)
 	visible_message("\The [src.name] flashes violently before disintegrating!")
+	SSmotiontracker.ping(src,100)
 	spawn(0)
 		qdel(s)
 		qdel(src)
@@ -173,6 +175,7 @@
 		if(!target.blocks_air)
 			target.assume_gas(GAS_N2O, 30)
 	visible_message("\The [src.name] detonates!")
+	SSmotiontracker.ping(src,100)
 	spawn(0)
 		qdel(src)
 
@@ -188,6 +191,7 @@
 			target.assume_gas(GAS_PHORON, 30)
 			target.hotspot_expose(1000, CELL_VOLUME)
 	visible_message("\The [src.name] detonates!")
+	SSmotiontracker.ping(src,100)
 	spawn(0)
 		qdel(src)
 
@@ -229,6 +233,7 @@
 		return
 	src.fragmentate(O, 20, 7, list(/obj/item/projectile/bullet/pellet/fragment)) //only 20 weak fragments because you're stepping directly on it
 	visible_message("\The [src.name] detonates!")
+	SSmotiontracker.ping(src,100)
 	spawn(0)
 		qdel(s)
 		qdel(src)
@@ -258,6 +263,7 @@
 	s.set_up(3, 1, src)
 	s.start()
 	visible_message("\The [src.name] flashes violently before disintegrating!")
+	SSmotiontracker.ping(src,100)
 	empulse(loc, 2, 4, 7, 10, 1) // As strong as an EMP grenade
 	spawn(0)
 		qdel(src)
@@ -279,6 +285,7 @@
 		M.adjust_fire_stacks(5)
 		M.fire_act()
 	visible_message("\The [src.name] bursts into flames!")
+	SSmotiontracker.ping(src,100)
 	spawn(0)
 		qdel(src)
 
@@ -300,6 +307,7 @@
 	else
 		explosion(loc, 0, 0, 2, 2)
 		visible_message("\The [src.name] detonates!")
+	SSmotiontracker.ping(src,100)
 
 	qdel(s)
 	qdel(src)

code/game/objects/effects/motion_echo.dm

@@ -0,0 +1,27 @@
+/image/motion_echo
+	plane = PLANE_FULLSCREEN
+	mouse_opacity = MOUSE_OPACITY_TRANSPARENT
+	appearance_flags = (RESET_COLOR|PIXEL_SCALE|KEEP_APART)
+	var/list/clients = list()
+
+/image/motion_echo/New(icon, loc, icon_state, layer, dir)
+	. = ..()
+	QDEL_IN(src, 2 SECONDS)
+
+/image/motion_echo/proc/place_from_root(var/turf/At)
+	var/rand_limit = 12
+	pixel_x += ((At.x - loc.x) * 32) + rand(-rand_limit,rand_limit)
+	pixel_y += ((At.y - loc.y) * 32) + rand(-rand_limit,rand_limit)
+
+/image/motion_echo/proc/append_client(var/datum/weakref/C)
+	var/client/CW = C?.resolve()
+	if(CW)
+		CW.images += src
+		clients.Add(C)
+
+/image/motion_echo/Destroy(force)
+	. = ..()
+	for(var/datum/weakref/C in clients)
+		var/client/CW = C?.resolve()
+		if(CW)
+			CW.images -= src

code/game/objects/effects/spiders.dm

@@ -223,6 +223,7 @@
 
 					if(prob(50))
 						src.visible_message(span_notice("You hear something squeezing through the ventilation ducts."),2)
+						SSmotiontracker.ping(src,10)
 					sleep(travel_time)
 
 					if(!exit_vent || exit_vent.welded)
@@ -269,6 +270,7 @@
 				walk_to(src, target_atom, 5)
 				if(prob(25))
 					src.visible_message(span_notice("\The [src] skitters[pick(" away"," around","")]."))
+				SSmotiontracker.ping(src,10)
 		else if(amount_grown < 75 && prob(5))
 			//vent crawl!
 			for(var/obj/machinery/atmospherics/unary/vent_pump/v in view(7,src))

code/game/objects/items/devices/scanners/motion_tracker.dm

@@ -0,0 +1,49 @@
+/obj/item/motiontracker
+	name = "Motion Tracker"
+	desc = "The \"Vibromaster V1.7\", a handheld motion tracker. Often picks up nearby vibrations as motion however."
+	icon = 'icons/obj/device_alt.dmi'
+	icon_state = "pinoff"
+	item_state = "analyzer"
+	w_class = ITEMSIZE_SMALL
+	slot_flags = SLOT_BELT
+	throwforce = 5
+	throw_speed = 4
+	throw_range = 20
+
+	matter = list(MAT_STEEL = 30,MAT_GLASS = 20)
+	origin_tech = list(TECH_MAGNET = 1, TECH_DATA = 1)
+
+	pickup_sound = 'sound/items/pickup/device.ogg'
+	drop_sound = 'sound/items/drop/device.ogg'
+
+/obj/item/motiontracker/Initialize(mapload)
+	RegisterSignal(SSmotiontracker, COMSIG_MOVABLE_MOTIONTRACKER, PROC_REF(handle_motion_tracking))
+	. = ..()
+
+/obj/item/motiontracker/Destroy(force, ...)
+	if(ismob(loc))
+		var/mob/M = loc
+		M.motiontracker_subscribe()
+	UnregisterSignal(SSmotiontracker, COMSIG_MOVABLE_MOTIONTRACKER)
+	. = ..()
+
+/obj/item/motiontracker/proc/handle_motion_tracking(mob/source, var/datum/weakref/RW, var/turf/T)
+	SIGNAL_HANDLER
+	SHOULD_NOT_OVERRIDE(TRUE)
+	PRIVATE_PROC(TRUE)
+	var/atom/echo_source = RW?.resolve()
+	var/atom/scan_pos = src
+	if(!isturf(loc))
+		scan_pos = loc
+	if(!echo_source || get_dist(scan_pos,echo_source) > SSmotiontracker.max_range || scan_pos.z != echo_source.z)
+		return
+	flick("pinondirect",src)
+
+/obj/item/motiontracker/Moved(atom/old_loc, direction, forced, movetime)
+	. = ..()
+	if(ismob(old_loc))
+		var/mob/M = old_loc
+		M.motiontracker_unsubscribe()
+	if(ismob(loc))
+		var/mob/M = loc
+		M.motiontracker_subscribe()

code/game/objects/items/weapons/grenades/grenade.dm

@@ -87,6 +87,7 @@
 	var/turf/T = get_turf(src)
 	if(T)
 		T.hotspot_expose(700,125)
+		SSmotiontracker.ping(src,100)
 
 
 /obj/item/grenade/attackby(obj/item/W as obj, mob/user as mob)

code/game/objects/items/weapons/traps.dm

@@ -131,6 +131,7 @@
 				span_danger("You step on \the [src]!"),
 				span_infoplain(span_bold("You hear a loud metallic snap!"))
 				)
+			SSmotiontracker.ping(src,100) // Clunk!
 			attack_mob(L)
 			if(!has_buckled_mobs())
 				anchored = FALSE