Use DVIEW (#6712)

# About the pull request

Switches several uses of `view` over to `dview` and related
procs/defines instead. Only swaps over where it would be inappropriate
for native BYOND darkness to effect the results, i.e. it cares about a
lack of obstructions rather than actual visibility.

Created `doview()` and `USE_DOVIEW` as the `oview` version of `dview`.

Tweaked `dview` and related procs to work slightly more like `view`
would. `view` is from the perspective of the provided atom, seeing
itself, its loc (usually a turf), and if on a turf, any surrounding
turfs. `dview` set its loc to the provided atom, meaning it was in the
*contents* of that atom, and would see itself and its loc (the atom)...
which, as an atom, means it wouldn't see surrounding turfs. Existing
uses of `dview` got around this by using `get_turf` on the provided
atom. I changed the behavior so this wasn't necessary, allowing you to
`dview` from the perspective of a atom and have it work like `view`
would.
Perhaps that should just be a built-in `get_turf` instead, but this more
closely matches how `view` works.

Used `HIDE_INVISIBLE_OBSERVER` as the see invis for `dview` as all the
uses I saw were for in-character things, and thus should only effect
things that were also in-character. Anything as invisible as an observer
or more is assumed to be out-of-character.

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# Explain why it's good for the game

Should (currently) have no effect on the game as native BYOND darkness
isn't used (all areas have luminosity), but is one step towards allowing
that system to work appropriately if enabled.
# Testing Photographs and Procedure
<details>
<summary>Screenshots & Videos</summary>

Performance testing. All procs in question return a list of atoms.
The procs of interest:

![image](https://github.com/user-attachments/assets/d4b487c9-5b8d-470e-8692-c7b2d8045d19)

Current, with darkness disabled (area luminosity = 1):

![image](https://github.com/user-attachments/assets/f6ab0229-c868-4f9c-a98a-541357dd0a65)
No performance difference between `view` and `dview`.

As a test, darkness enabled (area luminosity = 0):

![image](https://github.com/user-attachments/assets/bb60b345-0df7-45f3-8f09-a97fdfd43cd9)
`dview` is notably slower than `view`, likely because `view` has smaller
lists of things it can see due to darkness and thus shorter loops.

</details>


# Changelog
No player facing changes.

---------

Co-authored-by: Drathek <[email protected]>

code/__HELPERS/unsorted.dm

@@ -1340,29 +1340,35 @@ GLOBAL_LIST_INIT(WALLITEMS, list(
 GLOBAL_DATUM_INIT(dview_mob, /mob/dview, new)
 
 /// Version of view() which ignores darkness, because BYOND doesn't have it (I actually suggested it but it was tagged redundant, BUT HEARERS IS A T- /rant).
-/proc/dview(range = world.view, center, invis_flags = 0)
+/proc/dview(range = world.view, atom/center, invis_flags = 0)
 	if(!center)
 		return
 
-	GLOB.dview_mob.loc = center
-
+	GLOB.dview_mob.loc = isturf(center) ? center : center.loc
 	GLOB.dview_mob.see_invisible = invis_flags
 
-	. = view(range, GLOB.dview_mob)
+	. = oview(range, GLOB.dview_mob)
 	GLOB.dview_mob.loc = null
 
+/// Version of oview() which ignores darkness
+/proc/doview(range, atom/center, invis_flags)
+	if(!center)
+		return
+
+	return dview(range, center, invis_flags) - center
+
 /mob/dview
 	name = "INTERNAL DVIEW MOB"
-	invisibility = 101
+	invisibility = INVISIBILITY_ABSTRACT
 	density = FALSE
-	see_in_dark = 1e6
+	see_in_dark = INFINITY
 	var/ready_to_die = FALSE
 
 /mob/dview/Initialize() //Properly prevents this mob from gaining huds or joining any global lists
 	SHOULD_CALL_PARENT(FALSE)
-	if(flags_atom & INITIALIZED)
+	if(CHECK_BITFIELD(flags_atom, INITIALIZED))
 		stack_trace("Warning: [src]([type]) initialized multiple times!")
-	flags_atom |= INITIALIZED
+	ENABLE_BITFIELD(flags_atom, INITIALIZED)
 	return INITIALIZE_HINT_NORMAL
 
 /mob/dview/Destroy(force = FALSE)
@@ -1378,12 +1384,19 @@ GLOBAL_DATUM_INIT(dview_mob, /mob/dview, new)
 
 
 #define FOR_DVIEW(type, range, center, invis_flags) \
-	GLOB.dview_mob.loc = center;           \
+	GLOB.dview_mob.loc = isturf(center) ? (center) : (center).loc; \
 	GLOB.dview_mob.see_invisible = invis_flags; \
-	for(type in view(range, GLOB.dview_mob))
+	for(type in oview(range, GLOB.dview_mob))
 
 #define FOR_DVIEW_END GLOB.dview_mob.loc = null
 
+#define FOR_DOVIEW(type, range, center, invis_flags) \
+	GLOB.dview_mob.loc = isturf(center) ? (center) : (center).loc; \
+	GLOB.dview_mob.see_invisible = invis_flags; \
+	for(type in oview(range, GLOB.dview_mob) - (center))
+
+#define FOR_DOVIEW_END FOR_DVIEW_END
+
 /proc/get_turf_pixel(atom/AM)
 	if(!istype(AM))
 		return

code/datums/ammo/energy.dm

@@ -204,7 +204,7 @@
 
 /datum/ammo/energy/yautja/caster/sphere/stun/proc/do_area_stun(obj/projectile/P)
 	playsound(P, 'sound/weapons/wave.ogg', 75, 1, 25)
-	for (var/mob/living/carbon/M in view(src.stun_range, get_turf(P)))
+	FOR_DVIEW(var/mob/living/carbon/M, src.stun_range, get_turf(P), HIDE_INVISIBLE_OBSERVER)
 		var/stun_time = src.stun_time
 		log_attack("[key_name(M)] was stunned by a plasma immobilizer from [key_name(P.firer)] at [get_area(P)]")
 		if (isyautja(M))
@@ -214,6 +214,7 @@
 		to_chat(M, SPAN_DANGER("A powerful electric shock ripples through your body, freezing you in place!"))
 		M.apply_effect(stun_time, STUN)
 		M.apply_effect(stun_time, WEAKEN)
+	FOR_DVIEW_END
 
 /datum/ammo/energy/yautja/rifle/bolt
 	name = "plasma rifle bolt"

code/datums/beam.dm

@@ -215,17 +215,12 @@
 	return newbeam
 
 /proc/zap_beam(atom/source, zap_range, damage, list/blacklistmobs)
-	var/list/zap_data = list()
-	for(var/mob/living/carbon/xenomorph/beno in oview(zap_range, source))
-		zap_data += beno
-	for(var/xeno in zap_data)
-		var/mob/living/carbon/xenomorph/living = xeno
-		if(!living)
-			return
+	FOR_DOVIEW(var/mob/living/carbon/xenomorph/living, zap_range, source, HIDE_INVISIBLE_OBSERVER)
 		if(living.stat == DEAD)
 			continue
 		if(living in blacklistmobs)
 			continue
 		source.beam(living, icon_state="lightning[rand(1,12)]", time = 3, maxdistance = zap_range + 2)
 		living.set_effect(2, SLOW)
 		log_attack("[living] was zapped by [source]")
+	FOR_DOVIEW_END

code/datums/disease.dm

@@ -121,10 +121,11 @@ GLOBAL_LIST_INIT(diseases, typesof(/datum/disease) - /datum/disease)
 		check_range = 1 // everything else, like infect-on-contact things, only infect things on top of it
 
 	if(isturf(source.loc))
-		for(var/mob/living/carbon/victim in oview(check_range, source))
+		FOR_DOVIEW(var/mob/living/carbon/victim, check_range, source, HIDE_INVISIBLE_OBSERVER)
 			if(isturf(victim.loc))
 				if(AStar(source.loc, victim.loc, /turf/proc/AdjacentTurfs, /turf/proc/Distance, check_range))
 					victim.contract_disease(src, 0, 1, force_spread)
+		FOR_DOVIEW_END
 
 	return
 

code/datums/emergency_calls/cryo_marines.dm

@@ -37,10 +37,11 @@
 		human.create_hud()
 
 	if(!mind)
-		for(var/obj/structure/machinery/cryopod/pod in view(7,human))
+		FOR_DVIEW(var/obj/structure/machinery/cryopod/pod, 7, human, HIDE_INVISIBLE_OBSERVER)
 			if(pod && !pod.occupant)
 				pod.go_in_cryopod(human, silent = TRUE)
 				break
+		FOR_DVIEW_END
 
 	sleep(5)
 	var/datum/squad/marine/cryo/cryo_squad = GLOB.RoleAuthority.squads_by_type[/datum/squad/marine/cryo]

code/datums/emergency_calls/cryo_spec.dm

@@ -35,10 +35,11 @@
 		human.create_hud()
 
 	if(!mind)
-		for(var/obj/structure/machinery/cryopod/pod in view(7,human))
+		FOR_DVIEW(var/obj/structure/machinery/cryopod/pod, 7, human, HIDE_INVISIBLE_OBSERVER)
 			if(pod && !pod.occupant)
 				pod.go_in_cryopod(human, silent = TRUE)
 				break
+		FOR_DVIEW_END
 
 	sleep(5)
 	human.client?.prefs.copy_all_to(human, JOB_SQUAD_SPECIALIST, TRUE, TRUE)

code/game/machinery/camera/camera.dm

@@ -263,9 +263,11 @@ GLOBAL_LIST_EMPTY_TYPED(all_cameras, /obj/structure/machinery/camera)
 //Return a working camera that can see a given mob
 //or null if none
 /proc/seen_by_camera(mob/M)
-	for(var/obj/structure/machinery/camera/C in oview(4, M))
+	FOR_DOVIEW(var/obj/structure/machinery/camera/C, 4, M, HIDE_INVISIBLE_OBSERVER)
 		if(C.can_use()) // check if camera disabled
+			FOR_DOVIEW_END
 			return C
+	FOR_DOVIEW_END
 	return null
 
 /proc/near_range_camera(mob/M)

code/game/machinery/computer/almayer_control.dm

@@ -184,7 +184,7 @@
 				to_chat(user, SPAN_WARNING("Arrays are re-cycling.  Please stand by."))
 				return FALSE
 			var/input = stripped_input(user, "Please choose a message to transmit to USCM.  Please be aware that this process is very expensive, and abuse will lead to termination.  Transmission does not guarantee a response. There is a small delay before you may send another message. Be clear and concise.", "To abort, send an empty message.", "")
-			if(!input || !(user in view(1,src)) || !COOLDOWN_FINISHED(src, cooldown_central))
+			if(!input || !(user in dview(1, src)) || !COOLDOWN_FINISHED(src, cooldown_central))
 				return FALSE
 
 			high_command_announce(input, user)
@@ -211,7 +211,7 @@
 				to_chat(user, SPAN_WARNING("Please allow at least [COOLDOWN_TIMELEFT(src, cooldown_message)/10] second\s to pass between announcements."))
 				return FALSE
 			var/input = stripped_multiline_input(user, "Please write a message to announce to the station crew.", "Priority Announcement", "")
-			if(!input || !COOLDOWN_FINISHED(src, cooldown_message) || !(user in view(1,src)))
+			if(!input || !COOLDOWN_FINISHED(src, cooldown_message) || !(user in dview(1, src)))
 				return FALSE
 
 			var/signed = null

code/game/machinery/computer/communications.dm

@@ -134,7 +134,7 @@
 					to_chat(usr, SPAN_WARNING("Please allow at least [COOLDOWN_COMM_MESSAGE_LONG*0.1] second\s to pass between announcements."))
 					return FALSE
 				var/input = stripped_multiline_input(usr, "Please write a message to announce to the station crew.", "Priority Announcement", "")
-				if(!input || authenticated != 2 || world.time < cooldown_message + COOLDOWN_COMM_MESSAGE_LONG || !(usr in view(1,src)))
+				if(!input || authenticated != 2 || world.time < cooldown_message + COOLDOWN_COMM_MESSAGE_LONG || !(usr in dview(1, src)))
 					return FALSE
 
 				marine_announcement(input)
@@ -302,7 +302,7 @@
 					to_chat(usr, SPAN_WARNING("Arrays recycling.  Please stand by."))
 					return FALSE
 				var/input = stripped_input(usr, "Please choose a message to transmit to USCM.  Please be aware that this process is very expensive, and abuse will lead to termination.  Transmission does not guarantee a response. There is a small delay before you may send another message. Be clear and concise.", "To abort, send an empty message.", "")
-				if(!input || !(usr in view(1,src)) || authenticated != 2 || world.time < cooldown_central + COOLDOWN_COMM_CENTRAL) return FALSE
+				if(!input || !(usr in dview(1, src)) || authenticated != 2 || world.time < cooldown_central + COOLDOWN_COMM_CENTRAL) return FALSE
 
 				high_command_announce(input, usr)
 				to_chat(usr, SPAN_NOTICE("Message transmitted."))

code/game/machinery/computer/groundside_operations.dm

@@ -235,7 +235,7 @@
 				to_chat(usr, SPAN_WARNING("Access denied."))
 				return
 			var/input = stripped_multiline_input(usr, "Please write a message to announce to the station crew.", "Priority Announcement", "")
-			if(!input || !is_announcement_active || !(usr in view(1,src)))
+			if(!input || !is_announcement_active || !(usr in dview(1, src)))
 				return FALSE
 
 			is_announcement_active = FALSE

code/game/objects/effects/effect_system/chemsmoke.dm

@@ -57,10 +57,11 @@
 	targetTurfs = new()
 
 	//build affected area list
-	for(var/turf/T in view(range, location))
+	FOR_DVIEW(var/turf/T, range, location, HIDE_INVISIBLE_OBSERVER)
 		//cull turfs to circle
 		if(cheap_pythag(T.x - location.x, T.y - location.y) <= range)
 			targetTurfs += T
+	FOR_DVIEW_END
 
 	//make secondary list for reagents that affect walls
 	if(chemholder.reagents.has_reagent("thermite") || chemholder.reagents.has_reagent("plantbgone"))

code/game/objects/items/devices/cictablet.dm

@@ -104,7 +104,7 @@
 				return FALSE
 
 			var/input = stripped_multiline_input(user, "Please write a message to announce to the [MAIN_SHIP_NAME]'s crew and all groundside personnel.", "Priority Announcement", "")
-			if(!input || !COOLDOWN_FINISHED(src, announcement_cooldown) || !(user in view(1, src)))
+			if(!input || !COOLDOWN_FINISHED(src, announcement_cooldown) || !(user in dview(1, src)))
 				return FALSE
 
 			var/signed = null

code/game/objects/items/devices/pinpointer.dm

@@ -126,10 +126,10 @@
 			mode = 1
 
 			var/locationx = tgui_input_real_number(usr, "Please input the x coordinate to search for.", "Location?")
-			if(!locationx || !(usr in view(1,src)))
+			if(!locationx || !(usr in dview(1, src)))
 				return
 			var/locationy = tgui_input_real_number(usr, "Please input the y coordinate to search for.", "Location?")
-			if(!locationy || !(usr in view(1,src)))
+			if(!locationy || !(usr in dview(1, src)))
 				return
 
 			var/turf/Z = get_turf(src)

code/game/objects/structures/tables_racks.dm

@@ -385,9 +385,11 @@
 		to_chat(usr, SPAN_WARNING("You have moved a table too recently."))
 		return FALSE
 
-	for(var/mob/living/mob_behind_table in oview(src, 0))
+	FOR_DOVIEW(var/mob/living/mob_behind_table, 0, src, HIDE_INVISIBLE_OBSERVER)
 		to_chat(usr, SPAN_WARNING("[mob_behind_table] is in the way of [src]."))
+		FOR_DVIEW_END
 		return FALSE
+	FOR_DVIEW_END
 
 	var/list/directions = list()
 	if(direction)

code/game/turfs/turf.dm

@@ -478,18 +478,20 @@
 
 /turf/proc/AdjacentTurfs()
 	var/L[] = new()
-	for(var/turf/t in oview(src,1))
+	FOR_DOVIEW(var/turf/t, 1, src, HIDE_INVISIBLE_OBSERVER)
 		if(!t.density)
 			if(!LinkBlocked(src, t) && !TurfBlockedNonWindow(t))
 				L.Add(t)
+	FOR_DOVIEW_END
 	return L
 
 /turf/proc/AdjacentTurfsSpace()
 	var/L[] = new()
-	for(var/turf/t in oview(src,1))
+	FOR_DOVIEW(var/turf/t, 1, src, HIDE_INVISIBLE_OBSERVER)
 		if(!t.density)
 			if(!LinkBlocked(src, t) && !TurfBlockedNonWindow(t))
 				L.Add(t)
+	FOR_DOVIEW_END
 	return L
 
 /turf/proc/Distance(turf/t)

code/modules/cm_tech/droppod/droppod.dm

@@ -168,8 +168,9 @@
 	for(var/obj/structure/machinery/defenses/def in loc)
 		qdel(def)
 
-	for(var/mob/mob in view(7, loc))
+	FOR_DVIEW(var/mob/mob, 7, loc, HIDE_INVISIBLE_OBSERVER)
 		shake_camera(mob, 4, 5)
+	FOR_DVIEW_END
 
 	addtimer(CALLBACK(src, PROC_REF(open)), open_time)
 

code/modules/defenses/tesla_coil.dm

@@ -70,7 +70,7 @@
 /obj/structure/machinery/defenses/tesla_coil/proc/get_target()
 	targets = list()
 
-	for(var/mob/living/M in oview(tesla_range, src))
+	FOR_DOVIEW(var/mob/living/M, tesla_range, src, HIDE_INVISIBLE_OBSERVER)
 		if(M.stat == DEAD)
 			continue
 		if(HAS_TRAIT(M, TRAIT_CHARGING))
@@ -81,10 +81,12 @@
 			continue
 
 		targets += M
+	FOR_DOVIEW_END
 
-	for(var/obj/structure/machinery/defenses/D in oview(tesla_range, src))
+	FOR_DOVIEW(var/obj/structure/machinery/defenses/D, tesla_range, src, HIDE_INVISIBLE_OBSERVER)
 		if(D.turned_on)
 			targets += D
+	FOR_DOVIEW_END
 
 /obj/structure/machinery/defenses/tesla_coil/proc/fire(atoms)
 	if(!(world.time - last_fired >= fire_delay) || !turned_on)

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

@@ -134,9 +134,10 @@
 				return
 			if(RADIO_CHANNEL_INTERCOM)
 				message_mode = null
-				for(var/obj/item/device/radio/intercom/I in view(1))
+				FOR_DVIEW(var/obj/item/device/radio/intercom/I, 1, src, HIDE_INVISIBLE_OBSERVER)
 					used_radios += I
 					break // remove this if we EVER have two different intercomms with DIFFERENT frequencies IN ONE ROOM
+				FOR_DVIEW_END
 			else
 				if(message_mode != MESSAGE_MODE_LOCAL)
 					var/earpiece = get_type_in_ears(/obj/item/device/radio)

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

@@ -79,10 +79,11 @@
 				listening += C
 
 	//pass on the message to objects that can hear us.
-	for (var/obj/O in view(message_range, src))
+	FOR_DVIEW(var/obj/O, message_range, src, HIDE_INVISIBLE_OBSERVER)
 		spawn (0)
 			if (O)
 				O.hear_talk(src, message) //O.hear_talk(src, message, verb, speaking)
+	FOR_DVIEW_END
 
 	var/list/eavesdropping = hearers(eavesdropping_range, src)
 	eavesdropping -= src

code/modules/mob/living/carbon/xenomorph/Abilities.dm

@@ -144,16 +144,18 @@
 	xeno.visible_message(SPAN_XENOHIGHDANGER("[xeno] emits an ear-splitting guttural roar!"))
 	xeno.create_shriekwave(14) //Adds the visual effect. Wom wom wom, 14 shriekwaves
 
-	for(var/mob/mob in view())
+	FOR_DVIEW(var/mob/mob, world.view, owner, HIDE_INVISIBLE_OBSERVER)
 		if(mob && mob.client)
 			if(isxeno(mob))
 				shake_camera(mob, 10, 1)
 			else
 				shake_camera(mob, 30, 1) //50 deciseconds, SORRY 5 seconds was way too long. 3 seconds now
+	FOR_DVIEW_END
 
 	var/list/mobs_in_view = list()
-	for(var/mob/living/carbon/M in oview(7, xeno))
+	FOR_DOVIEW(var/mob/living/carbon/M, 7, xeno, HIDE_INVISIBLE_OBSERVER)
 		mobs_in_view += M
+	FOR_DOVIEW_END
 	for(var/mob/living/carbon/M in orange(10, xeno))
 		if(SEND_SIGNAL(M, COMSIG_MOB_SCREECH_ACT, xeno) & COMPONENT_SCREECH_ACT_CANCEL)
 			continue
@@ -247,14 +249,15 @@
 	var/whisper = strip_html(input("Message:", "Psychic Radiance") as text|null)
 	if(!whisper || !xeno_player.check_state(TRUE))
 		return
-	for(var/mob/living/possible_target in view(12, xeno_player))
+	FOR_DVIEW(var/mob/living/possible_target, 12, xeno_player, HIDE_INVISIBLE_OBSERVER)
 		if(possible_target == xeno_player || !possible_target.client)
 			continue
 		target_list += possible_target
 		if(!istype(possible_target, /mob/living/carbon/xenomorph))
 			to_chat(possible_target, SPAN_XENOQUEEN("You hear a strange, alien voice in your head. \"[whisper]\""))
 		else
 			to_chat(possible_target, SPAN_XENOQUEEN("You hear the voice of [xeno_player] resonate in your head. \"[whisper]\""))
+	FOR_DVIEW_END
 	if(!length(target_list))
 		return
 	var/targetstring = english_list(target_list)

code/modules/mob/living/carbon/xenomorph/abilities/predalien/predalien_powers.dm

@@ -13,7 +13,7 @@
 	playsound(xeno.loc, pick(predalien_roar), 75, 0, status = 0)
 	xeno.visible_message(SPAN_XENOHIGHDANGER("[xeno] emits a guttural roar!"))
 	xeno.create_shriekwave(7) //Adds the visual effect. Wom wom wom, 7 shriekwaves
-	for(var/mob/living/carbon/carbon in view(7, xeno))
+	FOR_DVIEW(var/mob/living/carbon/carbon, 7, xeno, HIDE_INVISIBLE_OBSERVER)
 		if(ishuman(carbon))
 			var/mob/living/carbon/human/human = carbon
 			human.disable_special_items()
@@ -29,6 +29,7 @@
 			if(!istype(behavior))
 				continue
 			new /datum/effects/xeno_buff(carbon, xeno, ttl = (0.25 SECONDS * behavior.kills + 3 SECONDS), bonus_damage = bonus_damage_scale * behavior.kills, bonus_speed = (bonus_speed_scale * behavior.kills))
+	FOR_DVIEW_END
 
 	apply_cooldown()
 	return ..()