Make monsters walk to spawn by chunked path (otland#3612)

Issues addressed: otland#3600
Supersedes PR: otland#3610

src/creature.cpp

@@ -211,11 +211,11 @@ void Creature::onWalk()
 				forceUpdateFollowPath = true;
 			}
 		} else {
+			stopEventWalk();
+
 			if (listWalkDir.empty()) {
 				onWalkComplete();
 			}
-
-			stopEventWalk();
 		}
 	}
 

src/luascript.cpp

@@ -2558,6 +2558,9 @@ void LuaScriptInterface::registerFunctions()
 	registerMethod("Monster", "selectTarget", LuaScriptInterface::luaMonsterSelectTarget);
 	registerMethod("Monster", "searchTarget", LuaScriptInterface::luaMonsterSearchTarget);
 
+	registerMethod("Monster", "isWalkingToSpawn", LuaScriptInterface::luaMonsterIsWalkingToSpawn);
+	registerMethod("Monster", "walkToSpawn", LuaScriptInterface::luaMonsterWalkToSpawn);
+
 	// Npc
 	registerClass("Npc", "Creature", LuaScriptInterface::luaNpcCreate);
 	registerMetaMethod("Npc", "__eq", LuaScriptInterface::luaUserdataCompare);
@@ -10635,6 +10638,30 @@ int LuaScriptInterface::luaMonsterSearchTarget(lua_State* L)
 	return 1;
 }
 
+int LuaScriptInterface::luaMonsterIsWalkingToSpawn(lua_State* L)
+{
+	// monster:isWalkingToSpawn()
+	Monster* monster = getUserdata<Monster>(L, 1);
+	if (monster) {
+		pushBoolean(L, monster->isWalkingToSpawn());
+	} else {
+		lua_pushnil(L);
+	}
+	return 1;
+}
+
+int LuaScriptInterface::luaMonsterWalkToSpawn(lua_State* L)
+{
+	// monster:walkToSpawn()
+	Monster* monster = getUserdata<Monster>(L, 1);
+	if (monster) {
+		pushBoolean(L, monster->walkToSpawn());
+	} else {
+		lua_pushnil(L);
+	}
+	return 1;
+}
+
 // Npc
 int LuaScriptInterface::luaNpcCreate(lua_State* L)
 {

src/luascript.h

@@ -1064,6 +1064,9 @@ class LuaScriptInterface
 		static int luaMonsterSelectTarget(lua_State* L);
 		static int luaMonsterSearchTarget(lua_State* L);
 
+		static int luaMonsterIsWalkingToSpawn(lua_State* L);
+		static int luaMonsterWalkToSpawn(lua_State* L);
+
 		// Npc
 		static int luaNpcCreate(lua_State* L);
 

src/monster.cpp

@@ -517,17 +517,13 @@ void Monster::onCreatureLeave(Creature* creature)
 	//update targetList
 	if (isOpponent(creature)) {
 		removeTarget(creature);
-		if (targetList.empty()) {
+		updateIdleStatus();
+
+		if (!isSummon() && targetList.empty()) {
 			int32_t walkToSpawnRadius = g_config.getNumber(ConfigManager::DEFAULT_WALKTOSPAWNRADIUS);
 			if (walkToSpawnRadius > 0 && !Position::areInRange(position, masterPos, walkToSpawnRadius, walkToSpawnRadius)) {
-				std::vector<Direction> dirList;
-				if (getPathTo(masterPos, dirList, 0, 0, true, true)) {
-					startAutoWalk(dirList);
-					return;
-				}
+				walkToSpawn();
 			}
-
-			updateIdleStatus();
 		}
 	}
 }
@@ -718,10 +714,6 @@ void Monster::updateIdleStatus()
 		}) == conditions.end();
 	}
 
-	if (idle) {
-		idle = listWalkDir.empty();
-	}
-
 	setIdle(idle);
 }
 
@@ -1059,11 +1051,41 @@ void Monster::onThinkYell(uint32_t interval)
 	}
 }
 
+bool Monster::walkToSpawn()
+{
+	if (walkingToSpawn || !spawn || !targetList.empty()) {
+		return false;
+	}
+
+	int32_t distance = std::max<int32_t>(Position::getDistanceX(position, masterPos), Position::getDistanceY(position, masterPos));
+	if (distance == 0) {
+		return false;
+	}
+
+	listWalkDir.clear();
+	if (!getPathTo(masterPos, listWalkDir, 0, std::max<int32_t>(0, distance - 5), true, true, distance)) {
+		return false;
+	}
+
+	walkingToSpawn = true;
+	startAutoWalk();
+	return true;
+}
+
 void Monster::onWalk()
 {
 	Creature::onWalk();
 }
 
+void Monster::onWalkComplete()
+{
+	// Continue walking to spawn
+	if (walkingToSpawn) {
+		walkingToSpawn = false;
+		walkToSpawn();
+	}
+}
+
 bool Monster::pushItem(Item* item)
 {
 	const Position& centerPos = item->getPosition();
@@ -1168,20 +1190,20 @@ void Monster::pushCreatures(Tile* tile)
 
 bool Monster::getNextStep(Direction& direction, uint32_t& flags)
 {
-	if (listWalkDir.empty() && (isIdle || getHealth() <= 0)) {
+	if (!walkingToSpawn && (isIdle || getHealth() <= 0)) {
 		//we don't have anyone watching, might as well stop walking
 		eventWalk = 0;
 		return false;
 	}
 
 	bool result = false;
-	if (listWalkDir.empty() && (!followCreature || !hasFollowPath) && (!isSummon() || !isMasterInRange)) {
+	if (!walkingToSpawn && (!followCreature || !hasFollowPath) && (!isSummon() || !isMasterInRange)) {
 		if (getTimeSinceLastMove() >= 1000) {
 			randomStepping = true;
 			//choose a random direction
 			result = getRandomStep(getPosition(), direction);
 		}
-	} else if ((isSummon() && isMasterInRange) || followCreature || !listWalkDir.empty()) {
+	} else if ((isSummon() && isMasterInRange) || followCreature || walkingToSpawn) {
 		randomStepping = false;
 		result = Creature::getNextStep(direction, flags);
 		if (result) {

src/monster.h

@@ -134,7 +134,13 @@ class Monster final : public Creature
 
 		void drainHealth(Creature* attacker, int32_t damage) override;
 		void changeHealth(int32_t healthChange, bool sendHealthChange = true) override;
+
+		bool isWalkingToSpawn() const {
+			return walkingToSpawn;
+		}
+		bool walkToSpawn();
 		void onWalk() override;
+		void onWalkComplete() override;
 		bool getNextStep(Direction& direction, uint32_t& flags) override;
 		void onFollowCreatureComplete(const Creature* creature) override;
 
@@ -203,10 +209,11 @@ class Monster final : public Creature
 
 		Position masterPos;
 
+		bool ignoreFieldDamage = false;
 		bool isIdle = true;
 		bool isMasterInRange = false;
 		bool randomStepping = false;
-		bool ignoreFieldDamage = false;
+		bool walkingToSpawn = false;
 
 		void onCreatureEnter(Creature* creature);
 		void onCreatureLeave(Creature* creature);