5 files changed, 171 insertions, 141 deletions

diff --git a/src/WorldStorage/FastNBT.cpp b/src/WorldStorage/FastNBT.cpp
index d5b9fd0f7..df93e21e4 100644
--- a/src/WorldStorage/FastNBT.cpp
+++ b/src/WorldStorage/FastNBT.cpp
@@ -637,6 +637,18 @@ void cFastNBTWriter::AddByteArray(const AString & a_Name, const char * a_Value,
 
 
 
+void cFastNBTWriter::AddByteArray(const AString & a_Name, size_t a_NumElements, unsigned char a_Value)
+{
+	TagCommon(a_Name, TAG_ByteArray);
+	UInt32 len = htonl(static_cast<UInt32>(a_NumElements));
+	m_Result.append(reinterpret_cast<const std::byte *>(&len), 4);
+	m_Result.append(a_NumElements, std::byte(a_Value));
+}
+
+
+
+
+
 void cFastNBTWriter::AddIntArray(const AString & a_Name, const Int32 * a_Value, size_t a_NumElements)
 {
 	TagCommon(a_Name, TAG_IntArray);
diff --git a/src/WorldStorage/FastNBT.h b/src/WorldStorage/FastNBT.h
index 0df520e21..d9c388179 100644
--- a/src/WorldStorage/FastNBT.h
+++ b/src/WorldStorage/FastNBT.h
@@ -340,6 +340,7 @@ public:
 	void AddDouble   (const AString & a_Name, double a_Value);
 	void AddString   (const AString & a_Name, std::string_view a_Value);
 	void AddByteArray(const AString & a_Name, const char * a_Value, size_t a_NumElements);
+	void AddByteArray(const AString & a_Name, size_t a_NumElements, unsigned char a_Value);
 	void AddIntArray (const AString & a_Name, const Int32 * a_Value, size_t a_NumElements);
 
 	void AddByteArray(const AString & a_Name, const AString & a_Value)
diff --git a/src/WorldStorage/NBTChunkSerializer.cpp b/src/WorldStorage/NBTChunkSerializer.cpp
index 2542cd2da..714c65a91 100644
--- a/src/WorldStorage/NBTChunkSerializer.cpp
+++ b/src/WorldStorage/NBTChunkSerializer.cpp
@@ -53,16 +53,14 @@
 
 
 /** Collects and stores the chunk data via the cChunkDataCallback interface */
-class SerializerCollector:
+class SerializerCollector final :
 	public cChunkDataCopyCollector
 {
 public:
 
 	// The data collected from the chunk:
-	cChunkDef::BiomeMap mBiomes;
-	UInt8 mVanillaBiomes[cChunkDef::Width * cChunkDef::Width];
-	int mVanillaHeightMap[cChunkDef::Width * cChunkDef::Width];
-	bool mBiomesAreValid;
+	UInt8 Biomes[cChunkDef::Width * cChunkDef::Width];
+	int Heights[cChunkDef::Width * cChunkDef::Width];
 
 	/** True if a tag has been opened in the callbacks and not yet closed. */
 	bool mIsTagOpen;
@@ -84,7 +82,6 @@ public:
 
 
 	SerializerCollector(cFastNBTWriter & aWriter):
-		mBiomesAreValid(false),
 		mIsTagOpen(false),
 		mHasHadEntity(false),
 		mHasHadBlockEntity(false),
@@ -106,14 +103,13 @@ public:
 
 
 
-	virtual void HeightMap(const cChunkDef::HeightMap * a_HeightMap) override
+	virtual void HeightMap(const cChunkDef::HeightMap & a_HeightMap) override
 	{
-		for (int RelX = 0; RelX < cChunkDef::Width; RelX++)
+		for (int RelZ = 0; RelZ < cChunkDef::Width; RelZ++)
 		{
-			for (int RelZ = 0; RelZ < cChunkDef::Width; RelZ++)
+			for (int RelX = 0; RelX < cChunkDef::Width; RelX++)
 			{
-				int Height = cChunkDef::GetHeight(*a_HeightMap, RelX, RelZ);
-				mVanillaHeightMap[(RelZ << 4) | RelX] = Height;
+				Heights[RelX + RelZ * cChunkDef::Width] = cChunkDef::GetHeight(a_HeightMap, RelX, RelZ);
 			}
 		}
 	}
@@ -122,15 +118,14 @@ public:
 
 
 
-	virtual void BiomeData(const cChunkDef::BiomeMap * a_BiomeMap) override
+	virtual void BiomeMap(const cChunkDef::BiomeMap & a_BiomeMap) override
 	{
-		memcpy(mBiomes, a_BiomeMap, sizeof(mBiomes));
-		for (size_t i = 0; i < ARRAYCOUNT(mBiomes); i++)
+		for (size_t i = 0; i < ARRAYCOUNT(Biomes); i++)
 		{
-			if ((*a_BiomeMap)[i] < 255)
+			if (a_BiomeMap[i] < 255)
 			{
 				// Normal MC biome, copy as-is:
-				mVanillaBiomes[i] = static_cast<Byte>((*a_BiomeMap)[i]);
+				Biomes[i] = static_cast<Byte>(a_BiomeMap[i]);
 			}
 			else
 			{
@@ -139,7 +134,6 @@ public:
 				return;
 			}
 		}  // for i - mBiomeMap[]
-		mBiomesAreValid = true;
 	}
 
 
@@ -252,13 +246,6 @@ public:
 			mWriter.EndList();
 		}
 
-		// If light not valid, reset it to defaults:
-		if (!mIsLightValid)
-		{
-			m_Data.FillBlockLight(0x00);
-			m_Data.FillSkyLight(0x0f);
-		}
-
 		// Check if "Entity" and "TileEntities" lists exists. MCEdit requires this.
 		if (!mHasHadEntity)
 		{
@@ -1187,40 +1174,57 @@ void NBTChunkSerializer::Serialize(const cWorld & aWorld, cChunkCoords aCoords,
 	ASSERT(Result);
 	serializer.Finish();  // Close NBT tags
 
-	// Save biomes, both MCS (IntArray) and MC-vanilla (ByteArray):
-	if (serializer.mBiomesAreValid)
-	{
-		aWriter.AddByteArray("Biomes",    reinterpret_cast<const char *>(serializer.mVanillaBiomes), ARRAYCOUNT(serializer.mVanillaBiomes));
-		aWriter.AddIntArray ("MCSBiomes", reinterpret_cast<const int *>(serializer.mBiomes),         ARRAYCOUNT(serializer.mBiomes));
-	}
+	// Save biomes:
+	aWriter.AddByteArray("Biomes", reinterpret_cast<const char *>(serializer.Biomes), ARRAYCOUNT(serializer.Biomes));
 
 	// Save heightmap (Vanilla require this):
-	aWriter.AddIntArray("HeightMap", reinterpret_cast<const int *>(serializer.mVanillaHeightMap), ARRAYCOUNT(serializer.mVanillaHeightMap));
+	aWriter.AddIntArray("HeightMap", reinterpret_cast<const int *>(serializer.Heights), ARRAYCOUNT(serializer.Heights));
 
 	// Save blockdata:
 	aWriter.BeginList("Sections", TAG_Compound);
-	for (size_t Y = 0; Y != cChunkData::NumSections; ++Y)
+	ChunkDef::ForEachSection(serializer.m_BlockData, serializer.m_LightData, [&aWriter](const auto Y, const auto Blocks, const auto Metas, const auto BlockLights, const auto SkyLights)
 	{
-		auto section = serializer.m_Data.GetSection(Y);
-		if (section == nullptr)
+		aWriter.BeginCompound("");
+
+		if (Blocks != nullptr)
 		{
-			continue;
+			aWriter.AddByteArray("Blocks", reinterpret_cast<const char *>(Blocks->data()), Blocks->size());
+		}
+		else
+		{
+			aWriter.AddByteArray("Blocks", ChunkBlockData::SectionBlockCount, ChunkBlockData::DefaultValue);
 		}
 
-		aWriter.BeginCompound("");
-		aWriter.AddByteArray("Blocks", reinterpret_cast<const char *>(section->m_BlockTypes), ARRAYCOUNT(section->m_BlockTypes));
-		aWriter.AddByteArray("Data",   reinterpret_cast<const char *>(section->m_BlockMetas), ARRAYCOUNT(section->m_BlockMetas));
+		if (Metas != nullptr)
+		{
+			aWriter.AddByteArray("Data", reinterpret_cast<const char *>(Metas->data()), Metas->size());
+		}
+		else
+		{
+			aWriter.AddByteArray("Data", ChunkBlockData::SectionMetaCount, ChunkBlockData::DefaultMetaValue);
+		}
+
+		if (BlockLights != nullptr)
+		{
+			aWriter.AddByteArray("BlockLight", reinterpret_cast<const char *>(BlockLights->data()), BlockLights->size());
+		}
+		else
+		{
+			aWriter.AddByteArray("BlockLight", ChunkLightData::SectionLightCount, ChunkLightData::DefaultBlockLightValue);
+		}
 
-		#ifdef DEBUG_SKYLIGHT
-			aWriter.AddByteArray("BlockLight", reinterpret_cast<const char *>(section->m_BlockSkyLight), ARRAYCOUNT(section->m_BlockSkyLight));
-		#else
-			aWriter.AddByteArray("BlockLight", reinterpret_cast<const char *>(section->m_BlockLight),    ARRAYCOUNT(section->m_BlockLight));
-		#endif
+		if (SkyLights != nullptr)
+		{
+			aWriter.AddByteArray("SkyLight", reinterpret_cast<const char *>(SkyLights->data()), SkyLights->size());
+		}
+		else
+		{
+			aWriter.AddByteArray("SkyLight", ChunkLightData::SectionLightCount, ChunkLightData::DefaultSkyLightValue);
+		}
 
-		aWriter.AddByteArray("SkyLight", reinterpret_cast<const char *>(section->m_BlockSkyLight), ARRAYCOUNT(section->m_BlockSkyLight));
 		aWriter.AddByte("Y", static_cast<unsigned char>(Y));
 		aWriter.EndCompound();
-	}
+	});
 	aWriter.EndList();  // "Sections"
 
 	// Store the information that the lighting is valid.
diff --git a/src/WorldStorage/WSSAnvil.cpp b/src/WorldStorage/WSSAnvil.cpp
index 78320d636..e2a9b1539 100644
--- a/src/WorldStorage/WSSAnvil.cpp
+++ b/src/WorldStorage/WSSAnvil.cpp
@@ -353,16 +353,7 @@ Compression::Result cWSSAnvil::SaveChunkToData(const cChunkCoords & a_Chunk)
 
 bool cWSSAnvil::LoadChunkFromNBT(const cChunkCoords & a_Chunk, const cParsedNBT & a_NBT, const ContiguousByteBufferView a_RawChunkData)
 {
-	// The data arrays, in MCA-native y / z / x ordering (will be reordered for the final chunk data)
-	cChunkDef::BlockTypes   BlockTypes;
-	cChunkDef::BlockNibbles MetaData;
-	cChunkDef::BlockNibbles BlockLight;
-	cChunkDef::BlockNibbles SkyLight;
-
-	memset(BlockTypes, 0,    sizeof(BlockTypes));
-	memset(MetaData,   0,    sizeof(MetaData));
-	memset(SkyLight,   0xff, sizeof(SkyLight));  // By default, data not present in the NBT means air, which means full skylight
-	memset(BlockLight, 0x00, sizeof(BlockLight));
+	struct SetChunkData Data(a_Chunk);
 
 	// Load the blockdata, blocklight and skylight:
 	int Level = a_NBT.FindChildByName(0, "Level");
@@ -371,12 +362,14 @@ bool cWSSAnvil::LoadChunkFromNBT(const cChunkCoords & a_Chunk, const cParsedNBT
 		ChunkLoadFailed(a_Chunk.m_ChunkX, a_Chunk.m_ChunkZ, "Missing NBT tag: Level", a_RawChunkData);
 		return false;
 	}
+
 	int Sections = a_NBT.FindChildByName(Level, "Sections");
 	if ((Sections < 0) || (a_NBT.GetType(Sections) != TAG_List))
 	{
 		ChunkLoadFailed(a_Chunk.m_ChunkX, a_Chunk.m_ChunkZ, "Missing NBT tag: Sections", a_RawChunkData);
 		return false;
 	}
+
 	eTagType SectionsType = a_NBT.GetChildrenType(Sections);
 	if ((SectionsType != TAG_Compound) && (SectionsType != TAG_End))
 	{
@@ -385,39 +378,56 @@ bool cWSSAnvil::LoadChunkFromNBT(const cChunkCoords & a_Chunk, const cParsedNBT
 	}
 	for (int Child = a_NBT.GetFirstChild(Sections); Child >= 0; Child = a_NBT.GetNextSibling(Child))
 	{
-		int y = 0;
-		int SectionY = a_NBT.FindChildByName(Child, "Y");
-		if ((SectionY < 0) || (a_NBT.GetType(SectionY) != TAG_Byte))
+		const int SectionYTag = a_NBT.FindChildByName(Child, "Y");
+		if ((SectionYTag < 0) || (a_NBT.GetType(SectionYTag) != TAG_Byte))
 		{
-			continue;
+			ChunkLoadFailed(a_Chunk.m_ChunkX, a_Chunk.m_ChunkZ, "NBT tag missing or has wrong: Y", a_RawChunkData);
+			return false;
 		}
-		y = a_NBT.GetByte(SectionY);
-		if ((y < 0) || (y > 15))
+
+		const int Y = a_NBT.GetByte(SectionYTag);
+		if ((Y < 0) || (Y > static_cast<int>(cChunkDef::NumSections - 1)))
 		{
-			continue;
+			ChunkLoadFailed(a_Chunk.m_ChunkX, a_Chunk.m_ChunkZ, "NBT tag exceeds chunk bounds: Y", a_RawChunkData);
+			return false;
+		}
+
+		const auto
+			BlockData = GetSectionData(a_NBT, Child, "Blocks", ChunkBlockData::SectionBlockCount),
+			MetaData = GetSectionData(a_NBT, Child, "Data", ChunkBlockData::SectionMetaCount),
+			BlockLightData = GetSectionData(a_NBT, Child, "BlockLight", ChunkLightData::SectionLightCount),
+			SkyLightData = GetSectionData(a_NBT, Child, "SkyLight", ChunkLightData::SectionLightCount);
+		if ((BlockData != nullptr) && (MetaData != nullptr) && (SkyLightData != nullptr) && (BlockLightData != nullptr))
+		{
+			Data.BlockData.SetSection(*reinterpret_cast<const ChunkBlockData::SectionType *>(BlockData), *reinterpret_cast<const ChunkBlockData::SectionMetaType *>(MetaData), static_cast<size_t>(Y));
+			Data.LightData.SetSection(*reinterpret_cast<const ChunkLightData::SectionType *>(BlockLightData), *reinterpret_cast<const ChunkLightData::SectionType *>(SkyLightData), static_cast<size_t>(Y));
+		}
+		else
+		{
+			ChunkLoadFailed(a_Chunk.m_ChunkX, a_Chunk.m_ChunkZ, "Missing chunk block/light data", a_RawChunkData);
+			return false;
 		}
-		CopyNBTData(a_NBT, Child, "Blocks",     reinterpret_cast<char *>(&(BlockTypes[y * 4096])), 4096);
-		CopyNBTData(a_NBT, Child, "Data",       reinterpret_cast<char *>(&(MetaData[y   * 2048])), 2048);
-		CopyNBTData(a_NBT, Child, "SkyLight",   reinterpret_cast<char *>(&(SkyLight[y   * 2048])), 2048);
-		CopyNBTData(a_NBT, Child, "BlockLight", reinterpret_cast<char *>(&(BlockLight[y * 2048])), 2048);
 	}  // for itr - LevelSections[]
 
-	// Load the biomes from NBT, if present and valid. First try MCS-style, then Vanilla-style:
-	cChunkDef::BiomeMap BiomeMap;
-	cChunkDef::BiomeMap * Biomes = LoadBiomeMapFromNBT(&BiomeMap, a_NBT, a_NBT.FindChildByName(Level, "MCSBiomes"));
-	if (Biomes == nullptr)
+	// Load the biomes from NBT, if present and valid:
+	if (!LoadBiomeMapFromNBT(Data.BiomeMap, a_NBT, a_NBT.FindChildByName(Level, "Biomes")))
+	{
+		ChunkLoadFailed(a_Chunk.m_ChunkX, a_Chunk.m_ChunkZ, "Missing chunk biome data", a_RawChunkData);
+		return false;
+	}
+
+	// Height map too:
+	if (!LoadHeightMapFromNBT(Data.HeightMap, a_NBT, a_NBT.FindChildByName(Level, "HeightMap")))
 	{
-		// MCS-style biomes not available, load vanilla-style:
-		Biomes = LoadVanillaBiomeMapFromNBT(&BiomeMap, a_NBT, a_NBT.FindChildByName(Level, "Biomes"));
+		ChunkLoadFailed(a_Chunk.m_ChunkX, a_Chunk.m_ChunkZ, "Missing chunk height data", a_RawChunkData);
+		return false;
 	}
 
 	// Load the entities from NBT:
-	cEntityList      Entities;
-	cBlockEntities   BlockEntities;
-	LoadEntitiesFromNBT     (Entities,      a_NBT, a_NBT.FindChildByName(Level, "Entities"));
-	LoadBlockEntitiesFromNBT(BlockEntities, a_NBT, a_NBT.FindChildByName(Level, "TileEntities"), BlockTypes, MetaData);
+	LoadEntitiesFromNBT     (Data.Entities,      a_NBT, a_NBT.FindChildByName(Level, "Entities"));
+	LoadBlockEntitiesFromNBT(Data.BlockEntities, a_NBT, a_NBT.FindChildByName(Level, "TileEntities"), Data.BlockData);
 
-	bool IsLightValid = (a_NBT.FindChildByName(Level, "MCSIsLightValid") > 0);
+	Data.IsLightValid = (a_NBT.FindChildByName(Level, "MCSIsLightValid") > 0);
 
 	/*
 	// Uncomment this block for really cool stuff :)
@@ -455,16 +465,7 @@ bool cWSSAnvil::LoadChunkFromNBT(const cChunkCoords & a_Chunk, const cParsedNBT
 	}  // for y
 	//*/
 
-	auto SetChunkData = std::make_unique<cSetChunkData>(
-		a_Chunk.m_ChunkX, a_Chunk.m_ChunkZ,
-		BlockTypes, MetaData,
-		IsLightValid ? BlockLight : nullptr,
-		IsLightValid ? SkyLight : nullptr,
-		nullptr, Biomes,
-		std::move(Entities), std::move(BlockEntities),
-		false
-	);
-	m_World->QueueSetChunkData(std::move(SetChunkData));
+	m_World->QueueSetChunkData(std::move(Data));
 	return true;
 }
 
@@ -472,69 +473,66 @@ bool cWSSAnvil::LoadChunkFromNBT(const cChunkCoords & a_Chunk, const cParsedNBT
 
 
 
-void cWSSAnvil::CopyNBTData(const cParsedNBT & a_NBT, int a_Tag, const AString & a_ChildName, char * a_Destination, size_t a_Length)
+bool cWSSAnvil::LoadBiomeMapFromNBT(cChunkDef::BiomeMap & a_BiomeMap, const cParsedNBT & a_NBT, const int a_TagIdx)
 {
-	int Child = a_NBT.FindChildByName(a_Tag, a_ChildName);
-	if ((Child >= 0) && (a_NBT.GetType(Child) == TAG_ByteArray) && (a_NBT.GetDataLength(Child) == a_Length))
+	if (
+		(a_TagIdx < 0) ||
+		(a_NBT.GetType(a_TagIdx) != TAG_ByteArray) ||
+		(a_NBT.GetDataLength(a_TagIdx) != std::size(a_BiomeMap))
+	)
 	{
-		memcpy(a_Destination, a_NBT.GetData(Child), a_Length);
+		return false;
 	}
-}
 
-
-
-
-
-cChunkDef::BiomeMap * cWSSAnvil::LoadVanillaBiomeMapFromNBT(cChunkDef::BiomeMap * a_BiomeMap, const cParsedNBT & a_NBT, int a_TagIdx)
-{
-	if ((a_TagIdx < 0) || (a_NBT.GetType(a_TagIdx) != TAG_ByteArray))
-	{
-		return nullptr;
-	}
-	if (a_NBT.GetDataLength(a_TagIdx) != 16 * 16)
+	const auto * const BiomeData = a_NBT.GetData(a_TagIdx);
+	for (size_t i = 0; i < ARRAYCOUNT(a_BiomeMap); i++)
 	{
-		// The biomes stored don't match in size
-		return nullptr;
-	}
-	const unsigned char * VanillaBiomeData = reinterpret_cast<const unsigned char *>(a_NBT.GetData(a_TagIdx));
-	for (size_t i = 0; i < ARRAYCOUNT(*a_BiomeMap); i++)
-	{
-		if ((VanillaBiomeData)[i] == 0xff)
+		if (BiomeData[i] > std::byte(EMCSBiome::biMaxVariantBiome))
 		{
-			// Unassigned biomes
-			return nullptr;
+			// Unassigned biomes:
+			return false;
 		}
-		(*a_BiomeMap)[i] = static_cast<EMCSBiome>(VanillaBiomeData[i]);
+
+		a_BiomeMap[i] = static_cast<EMCSBiome>(BiomeData[i]);
 	}
-	return a_BiomeMap;
+
+	return true;
 }
 
 
 
 
 
-cChunkDef::BiomeMap * cWSSAnvil::LoadBiomeMapFromNBT(cChunkDef::BiomeMap * a_BiomeMap, const cParsedNBT & a_NBT, int a_TagIdx)
+bool cWSSAnvil::LoadHeightMapFromNBT(cChunkDef::HeightMap & a_HeightMap, const cParsedNBT & a_NBT, const int a_TagIdx)
 {
-	if ((a_TagIdx < 0) || (a_NBT.GetType(a_TagIdx) != TAG_IntArray))
+	if (
+		(a_TagIdx < 0) ||
+		(a_NBT.GetType(a_TagIdx) != TAG_IntArray) ||
+		(a_NBT.GetDataLength(a_TagIdx) != (4 * std::size(a_HeightMap)))
+	)
 	{
-		return nullptr;
-	}
-	if (a_NBT.GetDataLength(a_TagIdx) != sizeof(*a_BiomeMap))
-	{
-		// The biomes stored don't match in size
-		return nullptr;
+		return false;
 	}
-	const auto * BiomeData = a_NBT.GetData(a_TagIdx);
-	for (size_t i = 0; i < ARRAYCOUNT(*a_BiomeMap); i++)
+
+	const auto * const HeightData = a_NBT.GetData(a_TagIdx);
+	for (int RelZ = 0; RelZ < cChunkDef::Width; RelZ++)
 	{
-		(*a_BiomeMap)[i] = static_cast<EMCSBiome>(GetBEInt(&BiomeData[i * 4]));
-		if ((*a_BiomeMap)[i] == 0xff)
+		for (int RelX = 0; RelX < cChunkDef::Width; RelX++)
 		{
-			// Unassigned biomes
-			return nullptr;
+			const int Index = 4 * (RelX + RelZ * cChunkDef::Width);
+			const int Height = GetBEInt(HeightData + Index);
+
+			if (Height > std::numeric_limits<HEIGHTTYPE>::max())
+			{
+				// Invalid data:
+				return false;
+			}
+
+			cChunkDef::SetHeight(a_HeightMap, RelX, RelZ, static_cast<HEIGHTTYPE>(Height));
 		}
 	}
-	return a_BiomeMap;
+
+	return true;
 }
 
 
@@ -575,7 +573,7 @@ void cWSSAnvil::LoadEntitiesFromNBT(cEntityList & a_Entities, const cParsedNBT &
 
 
 
-void cWSSAnvil::LoadBlockEntitiesFromNBT(cBlockEntities & a_BlockEntities, const cParsedNBT & a_NBT, int a_TagIdx, BLOCKTYPE * a_BlockTypes, NIBBLETYPE * a_BlockMetas)
+void cWSSAnvil::LoadBlockEntitiesFromNBT(cBlockEntities & a_BlockEntities, const cParsedNBT & a_NBT, int a_TagIdx, const ChunkBlockData & a_BlockData)
 {
 	if ((a_TagIdx < 0) || (a_NBT.GetType(a_TagIdx) != TAG_List))
 	{
@@ -596,11 +594,11 @@ void cWSSAnvil::LoadBlockEntitiesFromNBT(cBlockEntities & a_BlockEntities, const
 			LOGWARNING("Bad block entity, missing the coords. Will be ignored.");
 			continue;
 		}
-		auto relPos = cChunkDef::AbsoluteToRelative(absPos);
+		const auto relPos = cChunkDef::AbsoluteToRelative(absPos);
 
 		// Load the proper BlockEntity type based on the block type:
-		BLOCKTYPE BlockType = cChunkDef::GetBlock(a_BlockTypes, relPos);
-		NIBBLETYPE BlockMeta = cChunkDef::GetNibble(a_BlockMetas, relPos);
+		const auto BlockType = a_BlockData.GetBlock(relPos);
+		const auto BlockMeta = a_BlockData.GetMeta(relPos);
 		OwnedBlockEntity Entity;
 
 		try
@@ -3990,6 +3988,20 @@ bool cWSSAnvil::cMCAFile::GetChunkData(const cChunkCoords & a_Chunk, ContiguousB
 
 
 
+const std::byte * cWSSAnvil::GetSectionData(const cParsedNBT & a_NBT, int a_Tag, const AString & a_ChildName, size_t a_Length)
+{
+	int Child = a_NBT.FindChildByName(a_Tag, a_ChildName);
+	if ((Child >= 0) && (a_NBT.GetType(Child) == TAG_ByteArray) && (a_NBT.GetDataLength(Child) == a_Length))
+	{
+		return a_NBT.GetData(Child);
+	}
+	return nullptr;
+}
+
+
+
+
+
 bool cWSSAnvil::cMCAFile::SetChunkData(const cChunkCoords & a_Chunk, const ContiguousByteBufferView a_Data)
 {
 	if (!OpenFile(false))
diff --git a/src/WorldStorage/WSSAnvil.h b/src/WorldStorage/WSSAnvil.h
index 1751c6761..d37bf2d25 100755
--- a/src/WorldStorage/WSSAnvil.h
+++ b/src/WorldStorage/WSSAnvil.h
@@ -24,6 +24,7 @@ class cMonster;
 class cProjectileEntity;
 class cHangingEntity;
 class cUUID;
+class ChunkBlockData;
 
 
 
@@ -106,6 +107,9 @@ protected:
 	/** Gets chunk data from the correct file; locks file CS as needed */
 	bool GetChunkData(const cChunkCoords & a_Chunk, ContiguousByteBuffer & a_Data);
 
+	/** Copies a_Length bytes of data from the specified NBT Tag's Child into the a_Destination buffer */
+	const std::byte * GetSectionData(const cParsedNBT & a_NBT, int a_Tag, const AString & a_ChildName, size_t a_Length);
+
 	/** Sets chunk data into the correct file; locks file CS as needed */
 	bool SetChunkData(const cChunkCoords & a_Chunk, ContiguousByteBufferView a_Data);
 
@@ -119,17 +123,17 @@ protected:
 	a_RawChunkData is the raw (compressed) chunk data, used for offloading when chunk loading fails. */
 	bool LoadChunkFromNBT(const cChunkCoords & a_Chunk, const cParsedNBT & a_NBT, ContiguousByteBufferView a_RawChunkData);
 
-	/** Loads the chunk's biome map from vanilla-format; returns a_BiomeMap if biomes present and valid, nullptr otherwise */
-	cChunkDef::BiomeMap * LoadVanillaBiomeMapFromNBT(cChunkDef::BiomeMap * a_BiomeMap, const cParsedNBT & a_NBT, int a_TagIdx);
+	/** Loads the chunk's biome map into a_BiomeMap if biomes present and valid; returns false otherwise. */
+	bool LoadBiomeMapFromNBT(cChunkDef::BiomeMap & a_BiomeMap, const cParsedNBT & a_NBT, int a_TagIdx);
 
-	/** Loads the chunk's biome map from MCS format; returns a_BiomeMap if biomes present and valid, nullptr otherwise */
-	cChunkDef::BiomeMap * LoadBiomeMapFromNBT(cChunkDef::BiomeMap * a_BiomeMap, const cParsedNBT & a_NBT, int a_TagIdx);
+	/** Loads the chunk's height map into a_HeightMap if heights present and valid; returns false otherwise. */
+	bool LoadHeightMapFromNBT(cChunkDef::HeightMap & a_HeightMap, const cParsedNBT & a_NBT, int a_TagIdx);
 
 	/** Loads the chunk's entities from NBT data (a_Tag is the Level\\Entities list tag; may be -1) */
 	void LoadEntitiesFromNBT(cEntityList & a_Entitites, const cParsedNBT & a_NBT, int a_Tag);
 
 	/** Loads the chunk's BlockEntities from NBT data (a_Tag is the Level\\TileEntities list tag; may be -1) */
-	void LoadBlockEntitiesFromNBT(cBlockEntities & a_BlockEntitites, const cParsedNBT & a_NBT, int a_Tag, BLOCKTYPE * a_BlockTypes, NIBBLETYPE * a_BlockMetas);
+	void LoadBlockEntitiesFromNBT(cBlockEntities & a_BlockEntitites, const cParsedNBT & a_NBT, int a_Tag, const ChunkBlockData & a_BlockData);
 
 	/** Loads the data for a block entity from the specified NBT tag.
 	Returns the loaded block entity, or nullptr upon failure. */
@@ -298,9 +302,6 @@ protected:
 	/** Gets the correct MCA file either from cache or from disk, manages the m_MCAFiles cache; assumes m_CS is locked */
 	cMCAFile * LoadMCAFile(const cChunkCoords & a_Chunk);
 
-	/** Copies a_Length bytes of data from the specified NBT Tag's Child into the a_Destination buffer */
-	void CopyNBTData(const cParsedNBT & a_NBT, int a_Tag, const AString & a_ChildName, char * a_Destination, size_t a_Length);
-
 	// cWSSchema overrides:
 	virtual bool LoadChunk(const cChunkCoords & a_Chunk) override;
 	virtual bool SaveChunk(const cChunkCoords & a_Chunk) override;