From 9ff90bea11426410b1013611eadf9646af4fc12d Mon Sep 17 00:00:00 2001
From: MacHac <piheads@gmail.com>
Date: Wed, 27 Jun 2018 23:44:11 -0400
Subject: [PATCH] Added the pheromone receptor power to changelings.

---
 .../changeling/powers/pheromone_receptors.dm  | 57 +++++++++++++++++++
 .../traitor/IAA/internal_affairs.dm           |  5 +-
 tgstation.dme                                 |  1 +
 3 files changed, 61 insertions(+), 2 deletions(-)
 create mode 100644 code/modules/antagonists/changeling/powers/pheromone_receptors.dm

diff --git a/code/modules/antagonists/changeling/powers/pheromone_receptors.dm b/code/modules/antagonists/changeling/powers/pheromone_receptors.dm
new file mode 100644
index 00000000000..c3fe3c9bc0b
--- /dev/null
+++ b/code/modules/antagonists/changeling/powers/pheromone_receptors.dm
@@ -0,0 +1,57 @@
+#define CHANGELING_PHEROMONE_MIN_DISTANCE 10 //More generous than the agent pinpointer because you don't know who you're looking for.
+#define CHANGELING_PHEROMONE_MAX_DISTANCE 25 //They can smell your fear a mile away.  Well, 50 meters.
+#define CHANGELING_PHEROMONE_PING_TIME 20 //2s update time.
+
+
+/obj/effect/proc_holder/changeling/pheromone_receptors
+	name = "Pheromone Receptors"
+	desc = "We attune our senses to track other changelings by scent.  The closer they are, the easier we can find them."
+	helptext = "We will know the general direction of nearby changelings, with closer scents being stronger.  Our chemical generation is slowed while this is active."
+	chemical_cost = 0 //Reduces regain rate while active.
+	dna_cost = 2
+	var/receptors_active = FALSE
+
+/obj/effect/proc_holder/changeling/pheromone_receptors/sting_action(mob/living/carbon/user)
+	var/datum/antagonist/changeling/changeling = user.mind.has_antag_datum(/datum/antagonist/changeling)
+	if(!receptors_active)
+		to_chat(user, "<span class='warning'>We search for the scent of any nearby changelings.</span>")
+		changeling.chem_recharge_slowdown += 0.5
+		user.apply_status_effect(/datum/status_effect/agent_pinpointer/changeling)
+	else
+		to_chat(user, "<span class='notice'>We stop searching for now.</span>")
+		changeling.chem_recharge_slowdown -= 0.5
+		user.remove_status_effect(/datum/status_effect/agent_pinpointer/changeling)
+
+	receptors_active = !receptors_active
+
+//Modified IA pinpointer - Points to the NEAREST changeling, but will only get you within a few tiles of the target.
+//You'll still have to rely on intuition and observation to make the identification.  Lings can 'hide' in public places.
+/datum/status_effect/agent_pinpointer/changeling
+	alert_type = /obj/screen/alert/status_effect/agent_pinpointer/changeling
+	minimum_range = CHANGELING_PHEROMONE_MIN_DISTANCE
+	tick_interval = CHANGELING_PHEROMONE_PING_TIME
+	range_fuzz_factor = 0
+
+/datum/status_effect/agent_pinpointer/changeling/scan_for_target()
+	var/turf/my_loc = get_turf(owner)
+
+	var/list/mob/living/carbon/changelings = list()
+
+	for(var/mob/living/carbon/C in GLOB.alive_mob_list)
+		if(C != owner && C.mind)
+			var/datum/antagonist/changeling/antag_datum = C.mind.has_antag_datum(/datum/antagonist/changeling)
+			if(istype(antag_datum))
+				var/their_loc = get_turf(C)
+				var/distance = get_dist_euclidian(my_loc, their_loc)
+				if (distance < CHANGELING_PHEROMONE_MAX_DISTANCE)
+					changelings[C] = (CHANGELING_PHEROMONE_MAX_DISTANCE ** 2) - (distance ** 2)
+
+	if(changelings.len)
+		scan_target = pickweight(changelings) //Point at a 'random' changeling, biasing heavily towards closer ones.
+	else
+		scan_target = null
+
+
+/obj/screen/alert/status_effect/agent_pinpointer/changeling
+	name = "Pheromone Scent"
+	desc = "The nose always knows."
\ No newline at end of file
diff --git a/code/modules/antagonists/traitor/IAA/internal_affairs.dm b/code/modules/antagonists/traitor/IAA/internal_affairs.dm
index e17d1a23b47..85f4c4958de 100644
--- a/code/modules/antagonists/traitor/IAA/internal_affairs.dm
+++ b/code/modules/antagonists/traitor/IAA/internal_affairs.dm
@@ -44,6 +44,7 @@
 	tick_interval = PINPOINTER_PING_TIME
 	alert_type = /obj/screen/alert/status_effect/agent_pinpointer
 	var/minimum_range = PINPOINTER_MINIMUM_RANGE
+	var/range_fuzz_factor = PINPOINTER_EXTRA_RANDOM_RANGE
 	var/mob/scan_target = null
 
 /obj/screen/alert/status_effect/agent_pinpointer
@@ -61,7 +62,7 @@
 	if(here.z != there.z)
 		linked_alert.icon_state = "pinonnull"
 		return
-	if(get_dist_euclidian(here,there)<=minimum_range + rand(0, PINPOINTER_EXTRA_RANDOM_RANGE))
+	if(get_dist_euclidian(here,there)<=minimum_range + rand(0, range_fuzz_factor))
 		linked_alert.icon_state = "pinondirect"
 	else
 		linked_alert.setDir(get_dir(here, there))
@@ -228,7 +229,7 @@
 
 /datum/antagonist/traitor/internal_affairs/forge_traitor_objectives()
 	forge_iaa_objectives()
-	
+
 	var/objtype = traitor_kind == TRAITOR_HUMAN ? /datum/objective/escape : /datum/objective/survive
 	var/datum/objective/escape_objective = new objtype
 	escape_objective.owner = owner
diff --git a/tgstation.dme b/tgstation.dme
index 66e5915650e..eb2a29943a9 100755
--- a/tgstation.dme
+++ b/tgstation.dme
@@ -1144,6 +1144,7 @@
 #include "code\modules\antagonists\changeling\powers\mimic_voice.dm"
 #include "code\modules\antagonists\changeling\powers\mutations.dm"
 #include "code\modules\antagonists\changeling\powers\panacea.dm"
+#include "code\modules\antagonists\changeling\powers\pheromone_receptors.dm"
 #include "code\modules\antagonists\changeling\powers\regenerate.dm"
 #include "code\modules\antagonists\changeling\powers\revive.dm"
 #include "code\modules\antagonists\changeling\powers\shriek.dm"