♻️ Refactor AddMonster to return a monster pointer (#4894)

Source/debug.cpp

@@ -731,13 +731,12 @@ std::string DebugCmdSpawnUniqueMonster(const string_view parameter)
 			if (!IsTileWalkable(pos))
 				continue;
 
-			int mon = AddMonster(pos, myPlayer._pdir, id, true);
-			if (mon < 0)
+			Monster *monster = AddMonster(pos, myPlayer._pdir, id, true);
+			if (monster == nullptr)
 				return fmt::format("I could only summon {} Monsters. The rest strike for shorter working hours.", spawnedMonster);
-			auto &monster = Monsters[mon];
-			PrepareUniqueMonst(monster, uniqueIndex, 0, 0, UniqueMonstersData[uniqueIndex]);
+			PrepareUniqueMonst(*monster, uniqueIndex, 0, 0, UniqueMonstersData[uniqueIndex]);
 			ActiveMonsterCount--;
-			monster._udeadval = 1;
+			monster->_udeadval = 1;
 			spawnedMonster += 1;
 
 			if (spawnedMonster >= count)
@@ -816,7 +815,7 @@ std::string DebugCmdSpawnMonster(const string_view parameter)
 			if (!IsTileWalkable(pos))
 				continue;
 
-			if (AddMonster(pos, myPlayer._pdir, id, true) < 0)
+			if (AddMonster(pos, myPlayer._pdir, id, true) == nullptr)
 				return fmt::format("I could only summon {} Monsters. The rest strike for shorter working hours.", spawnedMonster);
 			spawnedMonster += 1;
 

Source/levels/themes.cpp

@@ -594,50 +594,50 @@ void Theme_SkelRoom(int t)
 	AddObject(OBJ_SKFIRE, { xp, yp });
 
 	if (GenerateRnd(monstrnd[leveltype - 1]) != 0) {
-		int i = PreSpawnSkeleton();
-		SpawnSkeleton(i, { xp - 1, yp - 1 });
+		Monster *skeleton = PreSpawnSkeleton();
+		SpawnSkeleton(skeleton, { xp - 1, yp - 1 });
 	} else {
 		AddObject(OBJ_BANNERL, { xp - 1, yp - 1 });
 	}
 
 	{
-		int i = PreSpawnSkeleton();
-		SpawnSkeleton(i, { xp, yp - 1 });
+		Monster *skeleton = PreSpawnSkeleton();
+		SpawnSkeleton(skeleton, { xp, yp - 1 });
 	}
 
 	if (GenerateRnd(monstrnd[leveltype - 1]) != 0) {
-		int i = PreSpawnSkeleton();
-		SpawnSkeleton(i, { xp + 1, yp - 1 });
+		Monster *skeleton = PreSpawnSkeleton();
+		SpawnSkeleton(skeleton, { xp + 1, yp - 1 });
 	} else {
 		AddObject(OBJ_BANNERR, { xp + 1, yp - 1 });
 	}
 	if (GenerateRnd(monstrnd[leveltype - 1]) != 0) {
-		int i = PreSpawnSkeleton();
-		SpawnSkeleton(i, { xp - 1, yp });
+		Monster *skeleton = PreSpawnSkeleton();
+		SpawnSkeleton(skeleton, { xp - 1, yp });
 	} else {
 		AddObject(OBJ_BANNERM, { xp - 1, yp });
 	}
 	if (GenerateRnd(monstrnd[leveltype - 1]) != 0) {
-		int i = PreSpawnSkeleton();
-		SpawnSkeleton(i, { xp + 1, yp });
+		Monster *skeleton = PreSpawnSkeleton();
+		SpawnSkeleton(skeleton, { xp + 1, yp });
 	} else {
 		AddObject(OBJ_BANNERM, { xp + 1, yp });
 	}
 	if (GenerateRnd(monstrnd[leveltype - 1]) != 0) {
-		int i = PreSpawnSkeleton();
-		SpawnSkeleton(i, { xp - 1, yp + 1 });
+		Monster *skeleton = PreSpawnSkeleton();
+		SpawnSkeleton(skeleton, { xp - 1, yp + 1 });
 	} else {
 		AddObject(OBJ_BANNERR, { xp - 1, yp + 1 });
 	}
 
 	{
-		int i = PreSpawnSkeleton();
-		SpawnSkeleton(i, { xp, yp + 1 });
+		Monster *skeleton = PreSpawnSkeleton();
+		SpawnSkeleton(skeleton, { xp, yp + 1 });
 	}
 
 	if (GenerateRnd(monstrnd[leveltype - 1]) != 0) {
-		int i = PreSpawnSkeleton();
-		SpawnSkeleton(i, { xp + 1, yp + 1 });
+		Monster *skeleton = PreSpawnSkeleton();
+		SpawnSkeleton(skeleton, { xp + 1, yp + 1 });
 	} else {
 		AddObject(OBJ_BANNERL, { xp + 1, yp + 1 });
 	}

Source/missiles.cpp

@@ -2952,9 +2952,9 @@ void MI_HorkSpawn(Missile &missile)
 
 		if (spawnPosition) {
 			auto facing = static_cast<Direction>(missile.var1);
-			int monsterId = AddMonster(*spawnPosition, facing, 1, true);
-			if (monsterId != -1) {
-				M_StartStand(Monsters[monsterId], facing);
+			Monster *monster = AddMonster(*spawnPosition, facing, 1, true);
+			if (monster != nullptr) {
+				M_StartStand(*monster, facing);
 			}
 		}
 	} else {

Source/monster.cpp

@@ -1710,7 +1710,7 @@ bool MonsterPetrified(Monster &monster)
 	return false;
 }
 
-int AddSkeleton(Point position, Direction dir, bool inMap)
+Monster *AddSkeleton(Point position, Direction dir, bool inMap)
 {
 	int j = 0;
 	for (int i = 0; i < LevelMonsterTypeCount; i++) {
@@ -1719,7 +1719,7 @@ int AddSkeleton(Point position, Direction dir, bool inMap)
 	}
 
 	if (j == 0) {
-		return -1;
+		return nullptr;
 	}
 
 	int skeltypes = GenerateRnd(j);
@@ -1733,9 +1733,9 @@ int AddSkeleton(Point position, Direction dir, bool inMap)
 
 void SpawnSkeleton(Point position, Direction dir)
 {
-	int skel = AddSkeleton(position, dir, true);
-	if (skel != -1)
-		StartSpecialStand(Monsters[skel], dir);
+	Monster *skeleton = AddSkeleton(position, dir, true);
+	if (skeleton != nullptr)
+		StartSpecialStand(*skeleton, dir);
 }
 
 bool IsLineNotSolid(Point startPoint, Point endPoint)
@@ -3813,17 +3813,17 @@ void SetMapMonsters(const uint16_t *dunData, Point startPosition)
 	}
 }
 
-int AddMonster(Point position, Direction dir, int mtype, bool inMap)
+Monster *AddMonster(Point position, Direction dir, int mtype, bool inMap)
 {
 	if (ActiveMonsterCount < MaxMonsters) {
-		int i = ActiveMonsters[ActiveMonsterCount++];
+		Monster &monster = Monsters[ActiveMonsters[ActiveMonsterCount++]];
 		if (inMap)
-			dMonster[position.x][position.y] = i + 1;
-		InitMonster(Monsters[i], dir, mtype, position);
-		return i;
+			dMonster[position.x][position.y] = monster.getId() + 1;
+		InitMonster(monster, dir, mtype, position);
+		return &monster;
 	}
 
-	return -1;
+	return nullptr;
 }
 
 void AddDoppelganger(Monster &monster)
@@ -4708,16 +4708,14 @@ bool IsGoat(_monster_id mt)
 	    MT_NGOATBW, MT_BGOATBW, MT_RGOATBW, MT_GGOATBW);
 }
 
-bool SpawnSkeleton(int ii, Point position)
+bool SpawnSkeleton(Monster *monster, Point position)
 {
-	if (ii == -1)
+	if (monster == nullptr)
 		return false;
 
-	Monster &monster = Monsters[ii];
-
 	if (IsTileAvailable(position)) {
 		Direction dir = GetDirection(position, position); // TODO useless calculation
-		ActivateSpawn(monster, position, dir);
+		ActivateSpawn(*monster, position, dir);
 		return true;
 	}
 
@@ -4757,18 +4755,18 @@ bool SpawnSkeleton(int ii, Point position)
 
 	Point spawn = position + Displacement { x2 - 1, y2 - 1 };
 	Direction dir = GetDirection(spawn, position);
-	ActivateSpawn(monster, spawn, dir);
+	ActivateSpawn(*monster, spawn, dir);
 
 	return true;
 }
 
-int PreSpawnSkeleton()
+Monster *PreSpawnSkeleton()
 {
-	int skel = AddSkeleton({ 0, 0 }, Direction::South, false);
-	if (skel != -1)
-		M_StartStand(Monsters[skel], Direction::South);
+	Monster *skeleton = AddSkeleton({ 0, 0 }, Direction::South, false);
+	if (skeleton != nullptr)
+		M_StartStand(*skeleton, Direction::South);
 
-	return skel;
+	return skeleton;
 }
 
 void TalktoMonster(Monster &monster)

Source/monster.h

@@ -301,7 +301,7 @@ void WeakenNaKrul();
 void InitGolems();
 void InitMonsters();
 void SetMapMonsters(const uint16_t *dunData, Point startPosition);
-int AddMonster(Point position, Direction dir, int mtype, bool inMap);
+Monster *AddMonster(Point position, Direction dir, int mtype, bool inMap);
 void AddDoppelganger(Monster &monster);
 bool M_Talker(const Monster &monster);
 void M_StartStand(Monster &monster, Direction md);
@@ -339,8 +339,8 @@ Monster *MonsterAtPosition(Point position);
 bool IsTileAvailable(const Monster &monster, Point position);
 bool IsSkel(_monster_id mt);
 bool IsGoat(_monster_id mt);
-bool SpawnSkeleton(int ii, Point position);
-int PreSpawnSkeleton();
+bool SpawnSkeleton(Monster *monster, Point position);
+Monster *PreSpawnSkeleton();
 void TalktoMonster(Monster &monster);
 void SpawnGolem(int id, Point position, Missile &missile);
 bool CanTalkToMonst(const Monster &monster);

Source/objects.cpp

@@ -1074,8 +1074,14 @@ void AddSarc(int i)
 	dObject[Objects[i].position.x][Objects[i].position.y - 1] = -(i + 1);
 	Objects[i]._oVar1 = GenerateRnd(10);
 	Objects[i]._oRndSeed = AdvanceRndSeed();
-	if (Objects[i]._oVar1 >= 8)
-		Objects[i]._oVar2 = PreSpawnSkeleton();
+	if (Objects[i]._oVar1 >= 8) {
+		Monster *monster = PreSpawnSkeleton();
+		if (monster != nullptr) {
+			Objects[i]._oVar2 = monster->getId();
+		} else {
+			Objects[i]._oVar2 = -1;
+		}
+	}
 }
 
 void AddFlameTrap(int i)
@@ -1127,8 +1133,14 @@ void AddBarrel(Object &barrel)
 	barrel._oVar2 = barrel.isExplosive() ? 0 : GenerateRnd(10);
 	barrel._oVar3 = GenerateRnd(3);
 
-	if (barrel._oVar2 >= 8)
-		barrel._oVar4 = PreSpawnSkeleton();
+	if (barrel._oVar2 >= 8) {
+		Monster *skeleton = PreSpawnSkeleton();
+		if (skeleton != nullptr) {
+			barrel._oVar4 = skeleton->getId();
+		} else {
+			barrel._oVar4 = -1;
+		}
+	}
 }
 
 void AddShrine(int i)
@@ -2494,8 +2506,8 @@ void OperateSarc(int i, bool sendMsg, bool sendLootMsg)
 	SetRndSeed(Objects[i]._oRndSeed);
 	if (Objects[i]._oVar1 <= 2)
 		CreateRndItem(Objects[i].position, false, sendLootMsg, false);
-	if (Objects[i]._oVar1 >= 8)
-		SpawnSkeleton(Objects[i]._oVar2, Objects[i].position);
+	if (Objects[i]._oVar1 >= 8 && Objects[i]._oVar2 >= 0)
+		SpawnSkeleton(&Monsters[Objects[i]._oVar2], Objects[i].position);
 	if (sendMsg)
 		NetSendCmdParam1(false, CMD_OPERATEOBJ, i);
 }
@@ -3855,8 +3867,8 @@ void BreakBarrel(int pnum, Object &barrel, bool forcebreak, bool sendmsg)
 			else
 				CreateRndItem(barrel.position, false, sendmsg, false);
 		}
-		if (barrel._oVar2 >= 8)
-			SpawnSkeleton(barrel._oVar4, barrel.position);
+		if (barrel._oVar2 >= 8 && barrel._oVar4 >= 0)
+			SpawnSkeleton(&Monsters[barrel._oVar4], barrel.position);
 	}
 	if (pnum == MyPlayerId) {
 		NetSendCmdParam2(false, CMD_BREAKOBJ, pnum, static_cast<uint16_t>(barrel.GetId()));