Amazing

zone/client.cpp

@@ -12968,6 +12968,18 @@ void Client::CheckSendBulkClientPositionUpdate()
 				}
 			}
 
+			// if we have seen this mob before and it hasn't moved, skip it
+			if (m_last_seen_mob_position.contains(mob->GetID())) {
+				if (m_last_seen_mob_position[mob->GetID()] == mob->GetPosition()) {
+					LogVisibilityDetail(
+						"Mob [{}] has already been sent to client [{}] at this position, skipping",
+						mob->GetCleanName(),
+						GetCleanName()
+					);
+					continue;
+				}
+			}
+
 			mob_movement_manager.SendCommandToClients(
 				mob,
 				0.0,

zone/client_packet.cpp

@@ -971,6 +971,8 @@ void Client::CompleteConnect()
 	RecordStats();
 	AutoGrantAAPoints();
 
+	m_last_seen_mob_position.reserve(entity_list.GetMobList().size());
+
 	// enforce some rules..
 	if (!CanEnterZone()) {
 		LogInfo("Kicking character [{}] from zone, not allowed here (missing requirements)", GetCleanName());

zone/entity.cpp

@@ -2870,6 +2870,7 @@ bool EntityList::RemoveMobFromCloseLists(Mob *mob)
 
 		it->second->m_close_mobs.erase(entity_id);
 		it->second->m_can_see_mob.erase(entity_id);
+		it->second->m_last_seen_mob_position.erase(entity_id);
 		++it;
 	}
 
@@ -2975,7 +2976,7 @@ void EntityList::ScanCloseMobs(Mob *scanning_mob)
 }
 
 BenchTimer g_vis_bench_timer;
-#define STATE_HIDDEN -1
+#define STATE_HIDDEN (-1)
 #define STATE_VISIBLE 1
 
 void EntityList::UpdateVisibility(Mob *scanning_mob) {

zone/entity.h

@@ -571,6 +571,7 @@ public:
 	void SendAlternateAdvancementStats();
 	void ScanCloseMobs(Mob *scanning_mob);
 	void UpdateVisibility(Mob *scanning_mob);
+	void UpdateKnownPositions(Mob *scanning_mob);
 
 	void GetTrapInfo(Client* c);
 	bool IsTrapGroupSpawned(uint32 trap_id, uint8 group);

zone/mob.h

@@ -201,11 +201,12 @@ public:
 
 	void DisplayInfo(Mob *mob);
 
-	std::unordered_map<uint16, Mob *> m_close_mobs;
-	std::unordered_map<int, int8>     m_can_see_mob;
-	Timer                             m_scan_close_mobs_timer;
-	Timer                             m_see_close_mobs_timer;
-	Timer                             m_mob_check_moving_timer;
+	std::unordered_map<uint16, Mob *>  m_close_mobs;
+	std::unordered_map<int, int8>      m_can_see_mob;
+	std::unordered_map<int, glm::vec4> m_last_seen_mob_position;
+	Timer                              m_scan_close_mobs_timer;
+	Timer                              m_see_close_mobs_timer;
+	Timer                              m_mob_check_moving_timer;
 
 	// Bot attack flag
 	Timer bot_attack_flag_timer;

zone/mob_movement_manager.cpp

@@ -852,6 +852,7 @@ void MobMovementManager::SendCommandToClients(
 			}
 
 			c->QueuePacket(&outapp, false);
+			c->m_last_seen_mob_position[mob->GetID()] = mob->GetPosition();
 		}
 	}
 	else {
@@ -902,6 +903,7 @@ void MobMovementManager::SendCommandToClients(
 				}
 
 				c->QueuePacket(&outapp, false);
+				c->m_last_seen_mob_position[mob->GetID()] = mob->GetPosition();
 			}
 		}
 	}