From d538bf0de028ffce037338e9135df2f1f26fa0e6 Mon Sep 17 00:00:00 2001
From: SkyratBot <59378654+SkyratBot@users.noreply.github.com>
Date: Thu, 28 Dec 2023 16:55:30 +0100
Subject: [PATCH] [MIRROR] Optimize find_potential_targets self cost [MDB
 IGNORE] (#25883)

* Optimize find_potential_targets self cost (#80602)

![image](https://github.com/tgstation/tgstation/assets/35135081/84ae20b6-5f44-4a69-bda3-0df1435dea5c)

`find_potential_targets/perform` currently has a pretty bad self cost in
part due to it running a second "loop over everything in range" check to
find turrets and mechs. This doesn't drop it down by as much as I'd like
because it still needs `hearers`, it still shows up pretty high, but
this at least cuts out some unnecessary work.

Best case is likely to minimize work AIs need to do when there are no
players on their z-level, as there are a lot of calls from Lavaland.

* Optimize find_potential_targets self cost

---------

Co-authored-by: Mothblocks <35135081+Mothblocks@users.noreply.github.com>
---
 .../ai/basic_mobs/basic_ai_behaviors/targeting.dm | 11 ++++++-----
 code/datums/elements/hostile_machine.dm           | 15 +++++++++++++++
 .../machinery/porta_turret/portable_turret.dm     |  2 ++
 code/modules/vehicles/mecha/_mecha.dm             |  1 +
 tgstation.dme                                     |  1 +
 5 files changed, 25 insertions(+), 5 deletions(-)
 create mode 100644 code/datums/elements/hostile_machine.dm

diff --git a/code/datums/ai/basic_mobs/basic_ai_behaviors/targeting.dm b/code/datums/ai/basic_mobs/basic_ai_behaviors/targeting.dm
index 435b9cb1ef3..8ba9624c21e 100644
--- a/code/datums/ai/basic_mobs/basic_ai_behaviors/targeting.dm
+++ b/code/datums/ai/basic_mobs/basic_ai_behaviors/targeting.dm
@@ -1,11 +1,12 @@
+/// List of objects that AIs will treat as targets
+GLOBAL_LIST_EMPTY_TYPED(hostile_machines, /atom)
+
 /datum/ai_behavior/find_potential_targets
 	action_cooldown = 2 SECONDS
 	/// How far can we see stuff?
 	var/vision_range = 9
 	/// Blackboard key for aggro range, uses vision range if not specified
 	var/aggro_range_key = BB_AGGRO_RANGE
-	/// Static typecache list of potentially dangerous objs
-	var/static/list/hostile_machines = typecacheof(list(/obj/machinery/porta_turret, /obj/vehicle/sealed/mecha))
 
 /datum/ai_behavior/find_potential_targets/perform(seconds_per_tick, datum/ai_controller/controller, target_key, targeting_strategy_key, hiding_location_key)
 	. = ..()
@@ -26,9 +27,9 @@
 
 	var/list/potential_targets = hearers(aggro_range, get_turf(controller.pawn)) - living_mob //Remove self, so we don't suicide
 
-	for(var/HM in typecache_filter_list(range(aggro_range, living_mob), hostile_machines)) //Can we see any hostile machines?
-		if(can_see(living_mob, HM, aggro_range))
-			potential_targets += HM
+	for (var/atom/hostile_machine as anything in GLOB.hostile_machines)
+		if (can_see(living_mob, hostile_machine, aggro_range))
+			potential_targets += hostile_machine
 
 	if(!potential_targets.len)
 		finish_action(controller, succeeded = FALSE)
diff --git a/code/datums/elements/hostile_machine.dm b/code/datums/elements/hostile_machine.dm
new file mode 100644
index 00000000000..0a5f19287bb
--- /dev/null
+++ b/code/datums/elements/hostile_machine.dm
@@ -0,0 +1,15 @@
+/// AIs will attack this as a potential target if they see it
+/datum/element/hostile_machine
+	element_flags = ELEMENT_DETACH_ON_HOST_DESTROY
+
+/datum/element/hostile_machine/Attach(datum/target)
+	. = ..()
+
+	if (!isatom(target))
+		return ELEMENT_INCOMPATIBLE
+
+	GLOB.hostile_machines += target
+
+/datum/element/hostile_machine/Detach(datum/source)
+	GLOB.hostile_machines -= source
+	return ..()
diff --git a/code/game/machinery/porta_turret/portable_turret.dm b/code/game/machinery/porta_turret/portable_turret.dm
index 5a7e1da9984..76b1b73ba53 100644
--- a/code/game/machinery/porta_turret/portable_turret.dm
+++ b/code/game/machinery/porta_turret/portable_turret.dm
@@ -133,6 +133,8 @@ DEFINE_BITFIELD(turret_flags, list(
 	if(!has_cover)
 		INVOKE_ASYNC(src, PROC_REF(popUp))
 
+	AddElement(/datum/element/hostile_machine)
+
 /obj/machinery/porta_turret/proc/toggle_on(set_to)
 	var/current = on
 	if (!isnull(set_to))
diff --git a/code/modules/vehicles/mecha/_mecha.dm b/code/modules/vehicles/mecha/_mecha.dm
index 208bd8d68c2..d971b82a856 100644
--- a/code/modules/vehicles/mecha/_mecha.dm
+++ b/code/modules/vehicles/mecha/_mecha.dm
@@ -267,6 +267,7 @@
 			equip_by_category[key] -= path
 
 	AddElement(/datum/element/falling_hazard, damage = 80, wound_bonus = 10, hardhat_safety = FALSE, crushes = TRUE)
+	AddElement(/datum/element/hostile_machine)
 
 /obj/vehicle/sealed/mecha/Destroy()
 	for(var/ejectee in occupants)
diff --git a/tgstation.dme b/tgstation.dme
index 1615237a9b7..07414c62a5f 100644
--- a/tgstation.dme
+++ b/tgstation.dme
@@ -1495,6 +1495,7 @@
 #include "code\datums\elements\haunted.dm"
 #include "code\datums\elements\high_fiver.dm"
 #include "code\datums\elements\honkspam.dm"
+#include "code\datums\elements\hostile_machine.dm"
 #include "code\datums\elements\human_biter.dm"
 #include "code\datums\elements\immerse.dm"
 #include "code\datums\elements\item_fov.dm"