From 6db48e1506e533550dd635bad2e7fd5beb8e2cae Mon Sep 17 00:00:00 2001
From: Jack Li <jackrjli@berkeley.edu>
Date: Tue, 8 Apr 2025 15:01:51 -0700
Subject: [PATCH] Prevent P_LookForPlayers from retrying sighting a player who
 failed (#528)

Mitigates the poor performance in Necromantic Thirst MAP25.

From Eternity Engine: https://github.com/team-eternity/eternity/commit/857826ba3e39041b072c50e911850000f8b17d8c
---
 src/p_enemy.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/p_enemy.c b/src/p_enemy.c
index 7da3ee21..6d366dae 100644
--- a/src/p_enemy.c
+++ b/src/p_enemy.c
@@ -816,6 +816,7 @@ static boolean P_LookForPlayers(mobj_t *actor, boolean allaround)
 {
   player_t *player;
   int stop, stopc, c;
+  boolean unseen[MAXPLAYERS] = {0};
 
   if (actor->flags & MF_FRIEND)
     {  // killough 9/9/98: friendly monsters go about players differently
@@ -891,8 +892,11 @@ static boolean P_LookForPlayers(mobj_t *actor, boolean allaround)
       if (player->health <= 0)
 	continue;               // dead
 
-      if (!P_IsVisible(actor, player->mo, allaround))
+      if (unseen[actor->lastlook] || !P_IsVisible(actor, player->mo, allaround))
+      {
+	unseen[actor->lastlook] = true;
 	continue;
+      }
       
       P_SetTarget(&actor->target, player->mo);