4 files changed, 107 insertions, 43 deletions

diff --git a/src/BlockEntities/BeaconEntity.cpp b/src/BlockEntities/BeaconEntity.cpp
index 1d088a56f..a98547ba7 100644
--- a/src/BlockEntities/BeaconEntity.cpp
+++ b/src/BlockEntities/BeaconEntity.cpp
@@ -1,4 +1,4 @@
-
+
 #include "Globals.h"  // NOTE: MSVC stupidness requires this to be the same across all modules
 
 #include "BeaconEntity.h"
@@ -195,21 +195,33 @@ void cBeaconEntity::UpdateBeacon(void)
 			GetWindow()->SetProperty(0, m_BeaconLevel);
 		}
 
-		Vector3d BeaconPosition(m_PosX, m_PosY, m_PosZ);
-		GetWorld()->ForEachPlayer([=](cPlayer & a_Player)
+		class cPlayerCallback :
+			public cPlayerListCallback
+		{
+		public:
+			cPlayerCallback(Vector3d a_Position):
+				m_Position(a_Position)
 			{
-				Vector3d Distance = BeaconPosition - a_Player.GetPosition();
+			}
+
+			virtual bool Item(cPlayer * a_Player)
+			{
+				Vector3d Distance = m_Position - a_Player->GetPosition();
 				if (
 					(std::abs(Distance.y) <= 14) &&
 					(std::abs(Distance.x) <= 20) &&
 					(std::abs(Distance.z) <= 20)
 				)
 				{
-					a_Player.AwardAchievement(eStatistic::achFullBeacon);
+					a_Player->AwardAchievement(eStatistic::achFullBeacon);
 				}
 				return false;
 			}
-		);
+
+		private:
+			Vector3d m_Position;
+		} PlayerCallback(Vector3d(m_PosX, m_PosY, m_PosZ));
+		GetWorld()->ForEachPlayer(PlayerCallback);
 	}
 }
 
@@ -237,28 +249,46 @@ void cBeaconEntity::GiveEffects(void)
 		SecondaryEffect = m_SecondaryEffect;
 	}
 
-	Vector3d BeaconPosition(m_PosX, m_PosY, m_PosZ);
-	GetWorld()->ForEachPlayer([=](cPlayer & a_Player)
+	class cPlayerCallback : public cPlayerListCallback
+	{
+		int m_Radius;
+		Vector3d m_Position;
+		cEntityEffect::eType m_PrimaryEffect, m_SecondaryEffect;
+		short m_EffectLevel;
+
+		virtual bool Item(cPlayer * a_Player)
 		{
-			auto PlayerPosition = a_Player.GetPosition();
-			if (PlayerPosition.y > BeaconPosition.y)
+			Vector3d PlayerPosition = Vector3d(a_Player->GetPosition());
+			if (PlayerPosition.y > m_Position.y)
 			{
-				PlayerPosition.y = BeaconPosition.y;
+				PlayerPosition.y = m_Position.y;
 			}
 
 			// TODO: Vanilla minecraft uses an AABB check instead of a radius one
-			if ((PlayerPosition - BeaconPosition).Length() <= Radius)
+			if ((PlayerPosition - m_Position).Length() <= m_Radius)
 			{
-				a_Player.AddEntityEffect(m_PrimaryEffect, 180, EffectLevel);
+				a_Player->AddEntityEffect(m_PrimaryEffect, 180, m_EffectLevel);
 
 				if (m_SecondaryEffect != cEntityEffect::effNoEffect)
 				{
-					a_Player.AddEntityEffect(m_SecondaryEffect, 180, 0);
+					a_Player->AddEntityEffect(m_SecondaryEffect, 180, 0);
 				}
 			}
 			return false;
 		}
-	);
+
+	public:
+		cPlayerCallback(int a_Radius, Vector3d a_Position, cEntityEffect::eType a_PrimaryEffect, cEntityEffect::eType a_SecondaryEffect, short a_EffectLevel):
+			m_Radius(a_Radius),
+			m_Position(a_Position),
+			m_PrimaryEffect(a_PrimaryEffect),
+			m_SecondaryEffect(a_SecondaryEffect),
+			m_EffectLevel(a_EffectLevel)
+		{
+		}
+
+	} PlayerCallback(Radius, Vector3d(m_PosX, m_PosY, m_PosZ), m_PrimaryEffect, SecondaryEffect, EffectLevel);
+	GetWorld()->ForEachPlayer(PlayerCallback);
 }
 
 
diff --git a/src/BlockEntities/ChestEntity.cpp b/src/BlockEntities/ChestEntity.cpp
index 5e8b29a45..a8f5b7242 100644
--- a/src/BlockEntities/ChestEntity.cpp
+++ b/src/BlockEntities/ChestEntity.cpp
@@ -138,18 +138,33 @@ bool cChestEntity::UsedBy(cPlayer * a_Player)
 void cChestEntity::ScanNeighbours()
 {
 	// Callback for finding neighbouring chest:
-	auto FindNeighbour = [this](cChestEntity & a_Chest)
+	class cFindNeighbour :
+		public cChestCallback
 	{
-		if (a_Chest.GetBlockType() != m_BlockType)
+	public:
+		cChestEntity * m_Neighbour;
+		BLOCKTYPE      m_ChestType;
+
+		cFindNeighbour(BLOCKTYPE a_ChestType) :
+			m_Neighbour(nullptr),
+			m_ChestType(a_ChestType)
 		{
-			// Neighboring block is not the same type of chest
-			return true;
 		}
-		m_Neighbour = &a_Chest;
-		return false;
+
+		virtual bool Item(cChestEntity * a_Chest) override
+		{
+			if (a_Chest->GetBlockType() != m_ChestType)
+			{
+				// Neighboring block is not the same type of chest
+				return true;
+			}
+			m_Neighbour = a_Chest;
+			return false;
+		}
 	};
 
 	// Scan horizontally adjacent blocks for any neighbouring chest of the same type:
+	cFindNeighbour FindNeighbour(m_BlockType);
 	if (
 		m_World->DoWithChestAt(m_PosX - 1, m_PosY, m_PosZ,     FindNeighbour) ||
 		m_World->DoWithChestAt(m_PosX + 1, m_PosY, m_PosZ,     FindNeighbour) ||
@@ -157,6 +172,7 @@ void cChestEntity::ScanNeighbours()
 		m_World->DoWithChestAt(m_PosX,     m_PosY, m_PosZ + 1, FindNeighbour)
 	)
 	{
+		m_Neighbour = FindNeighbour.m_Neighbour;
 		m_Neighbour->m_Neighbour = this;
 		// Force neighbour's window shut. Does Mojang server do this or should a double window open?
 		m_Neighbour->DestroyWindow();
diff --git a/src/BlockEntities/HopperEntity.cpp b/src/BlockEntities/HopperEntity.cpp
index 2fac188b1..0467685af 100644
--- a/src/BlockEntities/HopperEntity.cpp
+++ b/src/BlockEntities/HopperEntity.cpp
@@ -193,7 +193,8 @@ bool cHopperEntity::MovePickupsIn(cChunk & a_Chunk, Int64 a_CurrentTick)
 {
 	UNUSED(a_CurrentTick);
 
-	class cHopperPickupSearchCallback
+	class cHopperPickupSearchCallback :
+		public cEntityCallback
 	{
 	public:
 		cHopperPickupSearchCallback(const Vector3i & a_Pos, cItemGrid & a_Contents) :
@@ -203,20 +204,22 @@ bool cHopperEntity::MovePickupsIn(cChunk & a_Chunk, Int64 a_CurrentTick)
 		{
 		}
 
-		bool operator () (cEntity & a_Entity)
+		virtual bool Item(cEntity * a_Entity) override
 		{
-			if (!a_Entity.IsPickup())
+			ASSERT(a_Entity != nullptr);
+
+			if (!a_Entity->IsPickup())
 			{
 				return false;
 			}
 
-			Vector3f EntityPos = a_Entity.GetPosition();
+			Vector3f EntityPos = a_Entity->GetPosition();
 			Vector3f BlockPos(m_Pos.x + 0.5f, static_cast<float>(m_Pos.y) + 1, m_Pos.z + 0.5f);  // One block above hopper, and search from center outwards
 			double Distance = (EntityPos - BlockPos).Length();
 
 			if (Distance < 0.5)
 			{
-				if (TrySuckPickupIn(static_cast<cPickup &>(a_Entity)))
+				if (TrySuckPickupIn(static_cast<cPickup *>(a_Entity)))
 				{
 					return false;
 				}
@@ -225,9 +228,9 @@ bool cHopperEntity::MovePickupsIn(cChunk & a_Chunk, Int64 a_CurrentTick)
 			return false;
 		}
 
-		bool TrySuckPickupIn(cPickup & a_Pickup)
+		bool TrySuckPickupIn(cPickup * a_Pickup)
 		{
-			cItem & Item = a_Pickup.GetItem();
+			cItem & Item = a_Pickup->GetItem();
 
 			for (int i = 0; i < ContentsWidth * ContentsHeight; i++)
 			{
@@ -235,7 +238,7 @@ bool cHopperEntity::MovePickupsIn(cChunk & a_Chunk, Int64 a_CurrentTick)
 				{
 					m_bFoundPickupsAbove = true;
 					m_Contents.SetSlot(i, Item);
-					a_Pickup.Destroy();  // Kill pickup
+					a_Pickup->Destroy();  // Kill pickup
 
 					return true;
 				}
@@ -249,7 +252,7 @@ bool cHopperEntity::MovePickupsIn(cChunk & a_Chunk, Int64 a_CurrentTick)
 
 					if (Item.IsEmpty())
 					{
-						a_Pickup.Destroy();  // Kill pickup if all items were added
+						a_Pickup->Destroy();  // Kill pickup if all items were added
 					}
 					return true;
 				}
diff --git a/src/BlockEntities/MobSpawnerEntity.cpp b/src/BlockEntities/MobSpawnerEntity.cpp
index 8a4cc4d38..5246ae6ca 100644
--- a/src/BlockEntities/MobSpawnerEntity.cpp
+++ b/src/BlockEntities/MobSpawnerEntity.cpp
@@ -1,4 +1,4 @@
-
+
 #include "Globals.h"  // NOTE: MSVC stupidness requires this to be the same across all modules
 
 #include "MobSpawnerEntity.h"
@@ -138,36 +138,47 @@ void cMobSpawnerEntity::SpawnEntity(void)
 		return;
 	}
 
-	auto MobType = m_Entity;
-	bool EntitiesSpawned = m_World->DoWithChunk(GetChunkX(), GetChunkZ(), [&](cChunk & a_Chunk)
+	class cCallback : public cChunkCallback
+	{
+	public:
+		cCallback(int a_RelX, int a_RelY, int a_RelZ, eMonsterType a_MobType, int a_NearbyEntitiesNum) :
+			m_RelX(a_RelX),
+			m_RelY(a_RelY),
+			m_RelZ(a_RelZ),
+			m_MobType(a_MobType),
+			m_NearbyEntitiesNum(a_NearbyEntitiesNum)
+		{
+		}
+
+		virtual bool Item(cChunk * a_Chunk)
 		{
 			auto & Random = GetRandomProvider();
 
-			bool HaveSpawnedEntity = false;
+			bool EntitiesSpawned = false;
 			for (size_t i = 0; i < 4; i++)
 			{
-				if (NearbyEntities >= 6)
+				if (m_NearbyEntitiesNum >= 6)
 				{
 					break;
 				}
 
 				int RelX = m_RelX + static_cast<int>((Random.RandReal<double>() - Random.RandReal<double>()) * 4.0);
-				int RelY = m_PosY + Random.RandInt(-1, 1);
+				int RelY = m_RelY + Random.RandInt(-1, 1);
 				int RelZ = m_RelZ + static_cast<int>((Random.RandReal<double>() - Random.RandReal<double>()) * 4.0);
 
-				cChunk * Chunk = a_Chunk.GetRelNeighborChunkAdjustCoords(RelX, RelZ);
+				cChunk * Chunk = a_Chunk->GetRelNeighborChunkAdjustCoords(RelX, RelZ);
 				if ((Chunk == nullptr) || !Chunk->IsValid())
 				{
 					continue;
 				}
 				EMCSBiome Biome = Chunk->GetBiomeAt(RelX, RelZ);
 
-				if (cMobSpawner::CanSpawnHere(Chunk, RelX, RelY, RelZ, MobType, Biome))
+				if (cMobSpawner::CanSpawnHere(Chunk, RelX, RelY, RelZ, m_MobType, Biome))
 				{
 					double PosX = Chunk->GetPosX() * cChunkDef::Width + RelX;
 					double PosZ = Chunk->GetPosZ() * cChunkDef::Width + RelZ;
 
-					auto Monster = cMonster::NewMonsterFromType(MobType);
+					auto Monster = cMonster::NewMonsterFromType(m_MobType);
 					if (Monster == nullptr)
 					{
 						continue;
@@ -177,7 +188,7 @@ void cMobSpawnerEntity::SpawnEntity(void)
 					Monster->SetYaw(Random.RandReal(360.0f));
 					if (Chunk->GetWorld()->SpawnMobFinalize(std::move(Monster)) != cEntity::INVALID_ID)
 					{
-						HaveSpawnedEntity = true;
+						EntitiesSpawned = true;
 						Chunk->BroadcastSoundParticleEffect(
 							EffectID::PARTICLE_MOBSPAWN,
 							static_cast<int>(PosX * 8.0),
@@ -185,15 +196,19 @@ void cMobSpawnerEntity::SpawnEntity(void)
 							static_cast<int>(PosZ * 8.0),
 							0
 						);
-						NearbyEntities++;
+						m_NearbyEntitiesNum++;
 					}
 				}
 			}
 			return EntitiesSpawned;
 		}
-	);
+	protected:
+		int m_RelX, m_RelY, m_RelZ;
+		eMonsterType m_MobType;
+		int m_NearbyEntitiesNum;
+	} Callback(m_RelX, m_PosY, m_RelZ, m_Entity, NearbyEntities);
 
-	if (EntitiesSpawned)
+	if (m_World->DoWithChunk(GetChunkX(), GetChunkZ(), Callback))
 	{
 		ResetTimer();
 	}