Refactors beams. Adds tethering. IV drips/bags are now tethered. (#29570)

* refactor

* tether

* tetherrrs

* logic fix (i hope)

* ci fix

* ok please work

code/modules/antagonists/changeling/powers/mutations.dm

@@ -292,7 +292,7 @@
 
 /obj/item/projectile/tentacle/fire(setAngle)
 	if(firer)
-		chain = firer.Beam(src, icon_state = "tentacle", time = INFINITY, maxdistance = INFINITY, beam_sleep_time = 1)
+		chain = firer.Beam(src, icon_state = "tentacle", time = INFINITY, maxdistance = INFINITY)
 	..()
 
 /mob/proc/tentacle_stab(mob/living/carbon/C)

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

@@ -22,8 +22,7 @@
 	anchors += locate(x + 2, y - 2, z)
 
 	for(var/turf/T in anchors)
-		var/datum/beam/B = Beam(T, "vine", time=INFINITY, maxdistance=5, beam_type=/obj/effect/ebeam/vine)
-		B.sleep_time = 10 //these shouldn't move, so let's slow down updates to 1 second (any slower and the deletion of the vines would be too slow)
+		Beam(T, "vine", time = INFINITY, maxdistance = 5, beam_type = /obj/effect/ebeam/vine)
 	addtimer(CALLBACK(src, PROC_REF(bear_fruit)), growth_time)
 
 /obj/structure/alien/resin/flower_bud_enemy/proc/bear_fruit()
@@ -76,8 +75,7 @@
 		for(var/mob/living/L in grasping)
 			if(L.stat == DEAD)
 				var/datum/beam/B = grasping[L]
-				if(B)
-					B.End()
+				qdel(B)
 				grasping -= L
 
 			//Can attack+pull multiple times per cycle

code/modules/mod/modules/module_kinesis.dm

@@ -82,7 +82,7 @@
 	grabbed_atom.add_overlay(kinesis_icon)
 	pre_pixel_x = grabbed_atom.pixel_x
 	pre_pixel_y = grabbed_atom.pixel_y
-	beam.chain = beam.Beam(grabbed_atom, icon_state = "kinesis", icon='icons/effects/beam.dmi', time = 100 SECONDS, maxdistance = 15, beam_type = /obj/effect/ebeam, beam_sleep_time = 3)
+	beam.chain = beam.Beam(grabbed_atom, icon_state = "kinesis", icon='icons/effects/beam.dmi', time = 100 SECONDS, maxdistance = 15, beam_type = /obj/effect/ebeam)
 	kinesis_catcher = mod.wearer.overlay_fullscreen("kinesis", /atom/movable/screen/fullscreen/stretch/cursor_catcher/kinesis, 0)
 	kinesis_catcher.assign_to_mob(mod.wearer)
 	soundloop.start()
@@ -113,8 +113,7 @@
 		if(grabbed_atom.pixel_x == kinesis_catcher.given_x - world.icon_size/2 && grabbed_atom.pixel_y == kinesis_catcher.given_y - world.icon_size/2)
 			return //spare us redrawing if we are standing still
 		animate(grabbed_atom, 0.2 SECONDS, pixel_x = pre_pixel_x + kinesis_catcher.given_x - world.icon_size/2, pixel_y = pre_pixel_y + kinesis_catcher.given_y - world.icon_size/2)
-		beam.chain.Reset()
-		beam.chain.Draw()
+		beam.chain.redrawing()
 		return
 	animate(grabbed_atom, 0.2 SECONDS, pixel_x = pre_pixel_x + kinesis_catcher.given_x - world.icon_size/2, pixel_y = pre_pixel_y + kinesis_catcher.given_y - world.icon_size/2)
 	var/turf/next_turf = get_step_towards(grabbed_atom, kinesis_catcher.given_turf)
@@ -137,8 +136,7 @@
 	else if(direction & WEST)
 		pixel_x_change = -world.icon_size / 2
 	animate(grabbed_atom, 0.2 SECONDS, pixel_x = pre_pixel_x + pixel_x_change, pixel_y = pre_pixel_y + pixel_y_change) //Not as smooth as I would like, will look into this in the future
-	beam.chain.Reset()
-	beam.chain.Draw()
+	beam.chain.redrawing()
 	if(!isitem(grabbed_atom) || !COOLDOWN_FINISHED(src, hit_cooldown))
 		return
 	var/atom/hitting_atom

code/modules/projectiles/guns/medbeam.dm

@@ -54,9 +54,8 @@
 
 	current_target = target
 	active = TRUE
-	var/datum/beam/current_beam = new(user,current_target,time=6000,beam_icon_state="medbeam",btype=/obj/effect/ebeam/medical)
+	var/datum/beam/current_beam = user.Beam(current_target, "medbeam", time = 10 MINUTES, beam_type = /obj/effect/ebeam/medical)
 	beam_UID = current_beam.UID()
-	INVOKE_ASYNC(current_beam, TYPE_PROC_REF(/datum/beam, Start))
 
 	SSblackbox.record_feedback("tally", "gun_fired", 1, type)
 
@@ -87,6 +86,8 @@
 /obj/item/gun/medbeam/proc/los_check(atom/movable/user, mob/target)
 	var/turf/user_turf = user.loc
 	var/datum/beam/current_beam = locateUID(beam_UID)
+	if(QDELETED(current_beam))
+		return FALSE
 	if(mounted)
 		user_turf = get_turf(user)
 	else if(!istype(user_turf))
@@ -104,7 +105,7 @@
 				qdel(dummy)
 				return FALSE
 		for(var/obj/effect/ebeam/medical/B in turf)// Don't cross the str-beams!
-			if(B.owner != current_beam)
+			if(B.owner && B.owner != current_beam && !QDELETED(B)) // only blow up if it has a CONFIRMED different owner than us. Don't want it blowing up on creation/deletion of beams.
 				turf.visible_message("<span class='userdanger'>The medbeams cross and EXPLODE!</span>")
 				explosion(B.loc,0,3,5,8, cause = "Crossed beams")
 				qdel(dummy)

code/modules/reagents/reagent_containers/iv_bag.dm

@@ -18,6 +18,10 @@
 	var/mob/living/carbon/human/injection_target
 	var/injection_action_delay = 3 SECONDS
 
+/obj/item/reagent_containers/iv_bag/Initialize(mapload)
+	. = ..()
+	RegisterSignal(src, COMSIG_TETHER_DESTROYED, PROC_REF(tether_snapped))
+
 /obj/item/reagent_containers/iv_bag/Destroy()
 	end_processing()
 	return ..()
@@ -52,12 +56,34 @@
 	injection_target = target
 	RegisterSignal(injection_target, COMSIG_PARENT_EXAMINE, PROC_REF(on_examine))
 	START_PROCESSING(SSobj, src)
+	update_iv_type()
 
-/obj/item/reagent_containers/iv_bag/proc/end_processing()
+/obj/item/reagent_containers/iv_bag/proc/update_iv_type()
+	var/target = injection_target
+	injection_target = null
+	SEND_SIGNAL(src, COMSIG_TETHER_STOP)
+	injection_target = target
+	if(!injection_target)
+		return
+	if(istype(loc, /obj/machinery/iv_drip))
+		injection_target.AddComponent(/datum/component/tether, src, 2, 50, "iv_tether", "tubing")
+	else
+		injection_target.AddComponent(/datum/component/tether, src, 1, 5, "iv_tether", "tubing")
+
+/obj/item/reagent_containers/iv_bag/proc/end_processing(send_signal = TRUE)
 	if(injection_target)
 		UnregisterSignal(injection_target, COMSIG_PARENT_EXAMINE)
 	injection_target = null
 	STOP_PROCESSING(SSobj, src)
+	if(send_signal)
+		SEND_SIGNAL(src, COMSIG_TETHER_STOP)
+
+/obj/item/reagent_containers/iv_bag/proc/tether_snapped()
+	if(!injection_target)
+		return
+	to_chat(injection_target, "<span class='userdanger'>[src]'s needle is ripped out of you!</span>")
+	injection_target.apply_damage(3, BRUTE, pick("r_arm", "l_arm"))
+	end_processing(FALSE)
 
 /obj/item/reagent_containers/iv_bag/process()
 	if(QDELETED(injection_target))
@@ -69,12 +95,6 @@
 		end_processing()
 		return
 
-	if(get_dist(get_turf(src), get_turf(injection_target)) > 1)
-		to_chat(injection_target, "<span class='userdanger'>[src]'s needle is ripped out of you!</span>")
-		injection_target.apply_damage(3, BRUTE, pick("r_arm", "l_arm"))
-		end_processing()
-		return
-
 	if(mode) 	// Injecting
 		if(reagents.total_volume)
 			var/fraction = min(amount_per_transfer_from_this/reagents.total_volume, 1) 	//The amount of reagents we'll transfer to the person