From 52e86bd0edd464f54ef9e6ac638c74bbc17f10c2 Mon Sep 17 00:00:00 2001
From: dearmochi <1496804+dearmochi@users.noreply.github.com>
Date: Fri, 9 Jul 2021 12:39:37 +0200
Subject: [PATCH] Early stage viruses no longer show on medical HUD (#16307)

---
 code/datums/diseases/_disease.dm | 7 +++++++
 code/game/data_huds.dm           | 2 ++
 2 files changed, 9 insertions(+)

diff --git a/code/datums/diseases/_disease.dm b/code/datums/diseases/_disease.dm
index d099da71bf9..94efb17f630 100644
--- a/code/datums/diseases/_disease.dm
+++ b/code/datums/diseases/_disease.dm
@@ -50,6 +50,10 @@ GLOBAL_LIST_INIT(diseases, subtypesof(/datum/disease))
 	var/stage = 1
 	var/max_stages = 0
 	var/stage_prob = 4
+	/// The fraction of stages the virus must at least be at to show up on medical HUDs. Rounded up.
+	var/discovery_threshold = 0.5
+	/// If TRUE, this virus will show up on medical HUDs. Automatically set when it reaches mid-stage.
+	var/discovered = FALSE
 
 	//Other
 	var/list/viable_mobtypes = list() //typepaths of viable mobs
@@ -82,6 +86,9 @@ GLOBAL_LIST_INIT(diseases, subtypesof(/datum/disease))
 	if(!cure)
 		if(prob(stage_prob))
 			stage = min(stage + 1,max_stages)
+			if(!discovered && stage >= CEILING(max_stages * discovery_threshold, 1)) // Once we reach a late enough stage, medical HUDs can pick us up even if we regress
+				discovered = TRUE
+				affected_mob.med_hud_set_status()
 	else
 		if(prob(cure_chance))
 			stage = max(stage - 1, 1)
diff --git a/code/game/data_huds.dm b/code/game/data_huds.dm
index 61097b2c796..10e704fb314 100644
--- a/code/game/data_huds.dm
+++ b/code/game/data_huds.dm
@@ -90,6 +90,8 @@
 /mob/living/carbon/proc/has_virus()
 	for(var/thing in viruses)
 		var/datum/disease/D = thing
+		if(!D.discovered) // Early-stage viruses should not show up on med HUD (though health analywers can still pick them up)
+			continue
 		if((!(D.visibility_flags & HIDDEN_SCANNER)) && (D.severity != NONTHREAT))
 			return TRUE
 	return FALSE