refactor(creature): replace polling-based pathfinding with event-driven follow system

src/creature.cpp

@@ -126,12 +126,18 @@
 	tfs::events::creature::onThink(asCreature(), interval);
 }
 
-void Creature::forceUpdatePath()
+void Creature::updateFollowPath(bool force)
 {
-	if (attackedCreature.expired() && followCreature.expired()) {
+	if (followCreature.expired()) {
 		return;
 	}
 
+	if (!force) {
+		if (lastPathUpdate >= OTSYS_TIME()) {
+			return;
+		}
+	}
+
 	lastPathUpdate = OTSYS_TIME() + getNumber(ConfigManager::PATHFINDING_DELAY);
 	g_dispatcher.addTask(createTask([id = getID()]() { g_game.updateCreatureWalk(id); }));
 }
@@ -179,12 +185,7 @@
 		addEventWalk();
 	}
 
-	if (!attackedCreature.expired() || !followCreature.expired()) {
-		if (lastPathUpdate < OTSYS_TIME()) {
-			g_dispatcher.addTask(createTask([id = getID()]() { g_game.updateCreatureWalk(id); }));
-			lastPathUpdate = OTSYS_TIME() + getNumber(ConfigManager::PATHFINDING_DELAY);
-		}
-	}
+	updateFollowPath();
 }
 
 void Creature::onWalk(Direction& dir)
@@ -688,15 +689,12 @@
 	}
 
 	attackedCreature = creature;
-	creature->addFollower(asCreature());
 	onAttackedCreature(creature);
 
 	if (const auto& player = creature->asPlayer()) {
 		player->addInFightTicks();
 	}
 
-	forceUpdatePath();
-
 	for (const auto& summon : summons | tfs::views::lock_weak_ptrs) {
 		summon->setAttackedCreature(creature);
 	}
@@ -740,15 +738,24 @@
 		return;
 	}
 
-	followCreature = creature;
+	if (const auto& oldFollow = getFollowCreature()) {
+		oldFollow->removeFollower(asCreature());
+	}
 	creature->addFollower(asCreature());
+
+	followCreature = creature;
 	hasFollowPath = false;
 	onFollowCreature(creature);
-	forceUpdatePath();
+
+	updateFollowPath(true);
 }
 
 void Creature::removeFollowCreature()
 {
+	if (const auto& oldFollow = getFollowCreature()) {
+		oldFollow->removeFollower(asCreature());
+	}
+
 	followCreature.reset();
 	onUnfollowCreature();
 }
@@ -789,13 +796,9 @@
 	            }) |
 	            std::ranges::to<decltype(followers)>();
 
+	const auto size = followers.size();
 	for (const auto& follower : followers | tfs::views::lock_weak_ptrs) {
-		if (follower->lastPathUpdate < OTSYS_TIME()) {
-			continue;
-		}
-
-		g_dispatcher.addTask(createTask([id = follower->getID()]() { g_game.updateCreatureWalk(id); }));
-		follower->lastPathUpdate = OTSYS_TIME() + getNumber(ConfigManager::PATHFINDING_DELAY);
+		follower->updateFollowPath();
 	}
 }
 

src/creature.h

@@ -317,7 +317,7 @@ class Creature : public Thing
 	virtual void onThink(uint32_t interval);
 	virtual void onAttacking(uint32_t) {}
 
-	virtual void forceUpdatePath();
+	virtual void updateFollowPath(bool force = false);
 	virtual void onWalk();
 	virtual bool getNextStep(Direction& dir, uint32_t& flags);
 

src/game.cpp

@@ -3796,7 +3796,7 @@ void Game::updateCreaturesPath(size_t index)
 
 	for (const auto& creature : checkCreatureLists[index] | tfs::views::lock_weak_ptrs) {
 		if (!creature->isDead()) {
-			creature->forceUpdatePath();
+			creature->updateFollowPath(true);
 		}
 	}
 }