15 files changed, 303 insertions, 183 deletions

diff --git a/src/Blocks/BlockCauldron.h b/src/Blocks/BlockCauldron.h
index 37f274f18..28c1dfda8 100644
--- a/src/Blocks/BlockCauldron.h
+++ b/src/Blocks/BlockCauldron.h
@@ -19,11 +19,19 @@ public:
 	{
 	}
 
+
+
+
+
 	virtual cItems ConvertToPickups(NIBBLETYPE a_BlockMeta, cBlockEntity * a_BlockEntity, const cEntity * a_Digger, const cItem * a_Tool) override
 	{
 		return cItem(E_ITEM_CAULDRON, 1, 0);
 	}
 
+
+
+
+
 	virtual bool OnUse(cChunkInterface & a_ChunkInterface, cWorldInterface & a_WorldInterface, cPlayer & a_Player, int a_BlockX, int a_BlockY, int a_BlockZ, eBlockFace a_BlockFace, int a_CursorX, int a_CursorY, int a_CursorZ) override
 	{
 		NIBBLETYPE Meta = a_ChunkInterface.GetBlockMeta({a_BlockX, a_BlockY, a_BlockZ});
@@ -86,29 +94,45 @@ public:
 		return true;
 	}
 
+
+
+
+
 	virtual bool IsUseable() override
 	{
 		return true;
 	}
 
-	virtual void OnUpdate(cChunkInterface & a_ChunkInterface, cWorldInterface & a_WorldInterface, cBlockPluginInterface & a_PluginInterface, cChunk & a_Chunk, int a_RelX, int a_RelY, int a_RelZ) override
+
+
+
+
+	virtual void OnUpdate(
+		cChunkInterface & a_ChunkInterface,
+		cWorldInterface & a_WorldInterface,
+		cBlockPluginInterface & a_PluginInterface,
+		cChunk & a_Chunk,
+		const Vector3i a_RelPos
+	) override
 	{
-		int BlockX = a_RelX + a_Chunk.GetPosX() * cChunkDef::Width;
-		int BlockZ = a_RelZ + a_Chunk.GetPosZ() * cChunkDef::Width;
-		if (!a_WorldInterface.IsWeatherWetAt(BlockX, BlockZ) || (a_RelY != a_WorldInterface.GetHeight(BlockX, BlockZ)))
+		auto WorldPos = a_Chunk.RelativeToAbsolute(a_RelPos);
+		if (!a_WorldInterface.IsWeatherWetAtXYZ(WorldPos.addedY(1)))
 		{
 			// It's not raining at our current location or we do not have a direct view of the sky
-			// We cannot eat the rain :(
 			return;
 		}
 
-		NIBBLETYPE Meta = a_Chunk.GetMeta(a_RelX, a_RelY, a_RelZ);
+		auto Meta = a_Chunk.GetMeta(a_RelPos);
 		if (Meta < 3)
 		{
-			a_Chunk.SetMeta(a_RelX, a_RelY, a_RelZ, Meta + 1);
+			a_Chunk.SetMeta(a_RelPos, Meta + 1);
 		}
 	}
 
+
+
+
+
 	virtual ColourID GetMapBaseColourID(NIBBLETYPE a_Meta) override
 	{
 		UNUSED(a_Meta);
diff --git a/src/Blocks/BlockCocoaPod.h b/src/Blocks/BlockCocoaPod.h
index 11190e0ba..74b7c3caa 100644
--- a/src/Blocks/BlockCocoaPod.h
+++ b/src/Blocks/BlockCocoaPod.h
@@ -38,11 +38,17 @@ public:
 
 
 
-	virtual void OnUpdate(cChunkInterface & cChunkInterface, cWorldInterface & a_WorldInterface, cBlockPluginInterface & a_PluginInterface, cChunk & a_Chunk, int a_RelX, int a_RelY, int a_RelZ) override
+	virtual void OnUpdate(
+		cChunkInterface & a_ChunkInterface,
+		cWorldInterface & a_WorldInterface,
+		cBlockPluginInterface & a_PluginInterface,
+		cChunk & a_Chunk,
+		const Vector3i a_RelPos
+	) override
 	{
 		if (GetRandomProvider().RandBool(0.20))
 		{
-			Grow(a_Chunk, {a_RelX, a_RelY, a_RelZ});
+			Grow(a_Chunk, a_RelPos);
 		}
 	}
 
diff --git a/src/Blocks/BlockFarmland.h b/src/Blocks/BlockFarmland.h
index 20898b5e3..e5a55fcdd 100644
--- a/src/Blocks/BlockFarmland.h
+++ b/src/Blocks/BlockFarmland.h
@@ -41,26 +41,32 @@ public:
 
 
 
-	virtual void OnUpdate(cChunkInterface & cChunkInterface, cWorldInterface & a_WorldInterface, cBlockPluginInterface & a_PluginInterface, cChunk & a_Chunk, int a_RelX, int a_RelY, int a_RelZ) override
+	virtual void OnUpdate(
+		cChunkInterface & a_ChunkInterface,
+		cWorldInterface & a_WorldInterface,
+		cBlockPluginInterface & a_PluginInterface,
+		cChunk & a_Chunk,
+		const Vector3i a_RelPos
+	) override
 	{
-		NIBBLETYPE BlockMeta = a_Chunk.GetMeta(a_RelX, a_RelY, a_RelZ);
+		auto BlockMeta = a_Chunk.GetMeta(a_RelPos);
 
-		if (IsWaterInNear(a_Chunk, a_RelX, a_RelY, a_RelZ))
+		if (IsWaterInNear(a_Chunk, a_RelPos))
 		{
 			// Water was found, set block meta to 7
-			a_Chunk.FastSetBlock(a_RelX, a_RelY, a_RelZ, m_BlockType, 7);
+			a_Chunk.FastSetBlock(a_RelPos, m_BlockType, 7);
 			return;
 		}
 
 		// Water wasn't found, de-hydrate block:
 		if (BlockMeta > 0)
 		{
-			a_Chunk.FastSetBlock(a_RelX, a_RelY, a_RelZ, E_BLOCK_FARMLAND, --BlockMeta);
+			a_Chunk.FastSetBlock(a_RelPos, E_BLOCK_FARMLAND, --BlockMeta);
 			return;
 		}
 
 		// Farmland too dry. If nothing is growing on top, turn back to dirt:
-		BLOCKTYPE UpperBlock = (a_RelY >= cChunkDef::Height - 1) ? static_cast<BLOCKTYPE>(E_BLOCK_AIR) : a_Chunk.GetBlock(a_RelX, a_RelY + 1, a_RelZ);
+		auto UpperBlock = cChunkDef::IsValidHeight(a_RelPos.y + 1) ? a_Chunk.GetBlock(a_RelPos.addedY(1)) : E_BLOCK_AIR;
 		switch (UpperBlock)
 		{
 			case E_BLOCK_BEETROOTS:
@@ -75,7 +81,7 @@ public:
 			}
 			default:
 			{
-				a_Chunk.SetBlock({a_RelX, a_RelY, a_RelZ}, E_BLOCK_DIRT, 0);
+				a_Chunk.SetBlock(a_RelPos, E_BLOCK_DIRT, 0);
 				break;
 			}
 		}
@@ -111,11 +117,12 @@ public:
 
 
 
-	bool IsWaterInNear(cChunk & a_Chunk, int a_RelX, int a_RelY, int a_RelZ)
+	/** Returns true if there's either a water source block close enough to hydrate the specified position, or it's raining there. */
+	bool IsWaterInNear(cChunk & a_Chunk, const Vector3i a_RelPos)
 	{
-		if (a_Chunk.GetWorld()->IsWeatherWetAt(a_RelX, a_RelZ))
+		if (a_Chunk.GetWorld()->IsWeatherWetAtXYZ(a_RelPos))
 		{
-			// Rain hydrates farmland, too, except in Desert biomes.
+			// Rain hydrates farmland, too
 			return true;
 		}
 
@@ -123,9 +130,8 @@ public:
 		// Ref.: https://minecraft.gamepedia.com/Farmland#Hydration
 		// TODO: Rewrite this to use the chunk and its neighbors directly
 		cBlockArea Area;
-		int BlockX = a_RelX + a_Chunk.GetPosX() * cChunkDef::Width;
-		int BlockZ = a_RelZ + a_Chunk.GetPosZ() * cChunkDef::Width;
-		if (!Area.Read(*a_Chunk.GetWorld(), BlockX - 4, BlockX + 4, a_RelY, a_RelY + 1, BlockZ - 4, BlockZ + 4))
+		auto WorldPos = a_Chunk.RelativeToAbsolute(a_RelPos);
+		if (!Area.Read(*a_Chunk.GetWorld(), WorldPos - Vector3i(4, 0, 4), WorldPos + Vector3i(4, 1, 4)))
 		{
 			// Too close to the world edge, cannot check surroundings
 			return false;
@@ -144,6 +150,10 @@ public:
 		return false;
 	}
 
+
+
+
+
 	virtual bool CanSustainPlant(BLOCKTYPE a_Plant) override
 	{
 		return (
diff --git a/src/Blocks/BlockFluid.h b/src/Blocks/BlockFluid.h
index 36f363a92..e856dba38 100644
--- a/src/Blocks/BlockFluid.h
+++ b/src/Blocks/BlockFluid.h
@@ -80,6 +80,10 @@ public:
 		return 0;
 	}
 
+
+
+
+
 	virtual bool CanSustainPlant(BLOCKTYPE a_Plant) override
 	{
 		return (
@@ -109,33 +113,47 @@ public:
 	{
 	}
 
-	/** Called to tick the block */
-	virtual void OnUpdate(cChunkInterface & cChunkInterface, cWorldInterface & a_WorldInterface, cBlockPluginInterface & a_PluginInterface, cChunk & a_Chunk, int a_RelX, int a_RelY, int a_RelZ) override
+
+
+
+
+	virtual void OnUpdate(
+		cChunkInterface & a_ChunkInterface,
+		cWorldInterface & a_WorldInterface,
+		cBlockPluginInterface & a_PluginInterface,
+		cChunk & a_Chunk,
+		const Vector3i a_RelPos
+	) override
 	{
 		if (a_Chunk.GetWorld()->ShouldLavaSpawnFire())
 		{
 			// Try to start up to 5 fires:
 			for (int i = 0; i < 5; i++)
 			{
-				TryStartFireNear(a_RelX, a_RelY, a_RelZ, a_Chunk);
+				TryStartFireNear(a_RelPos, a_Chunk);
 			}
 		}
 	}
 
+
+
+
+
 	/** Tries to start a fire near the lava at given coords. Returns true if fire started. */
-	static bool TryStartFireNear(int a_RelX, int a_RelY, int a_RelZ, cChunk & a_Chunk)
+	static bool TryStartFireNear(const Vector3i a_RelPos, cChunk & a_Chunk)
 	{
-		// Pick a block next to this lava block:
+		// Pick a random block next to this lava block:
 		int rnd = a_Chunk.GetWorld()->GetTickRandomNumber(cChunkDef::NumBlocks * 8) / 7;
 		int x = (rnd % 3) - 1;         // -1 .. 1
 		int y = ((rnd / 4) % 4) - 1;   // -1 .. 2
 		int z = ((rnd / 16) % 3) - 1;  // -1 .. 1
+		auto Pos = a_RelPos + Vector3i(x, y, z);
 
 		// Check if it's fuel:
 		BLOCKTYPE BlockType;
 		if (
-			((a_RelY + y < 0) || (a_RelY + y >= cChunkDef::Height)) ||
-			!a_Chunk.UnboundedRelGetBlockType(a_RelX + x, a_RelY + y, a_RelZ + z, BlockType) ||
+			!cChunkDef::IsValidHeight(Pos.y) ||
+			!a_Chunk.UnboundedRelGetBlockType(Pos, BlockType) ||
 			!cFireSimulator::IsFuel(BlockType)
 		)
 		{
@@ -143,10 +161,7 @@ public:
 		}
 
 		// Try to set it on fire:
-		static struct
-		{
-			int x, y, z;
-		} CrossCoords[] =
+		static Vector3i CrossCoords[] =
 		{
 			{-1,  0,  0},
 			{ 1,  0,  0},
@@ -155,31 +170,37 @@ public:
 			{ 0,  0, -1},
 			{ 0,  0,  1},
 		} ;
-		int RelX = a_RelX + x;
-		int RelY = a_RelY + y;
-		int RelZ = a_RelZ + z;
 		for (size_t i = 0; i < ARRAYCOUNT(CrossCoords); i++)
 		{
+			auto NeighborPos = Pos + CrossCoords[i];
 			if (
-				((RelY + CrossCoords[i].y >= 0) && (RelY + CrossCoords[i].y < cChunkDef::Height)) &&
-				a_Chunk.UnboundedRelGetBlockType(RelX + CrossCoords[i].x, RelY + CrossCoords[i].y, RelZ + CrossCoords[i].z, BlockType) &&
+				cChunkDef::IsValidHeight(NeighborPos.y) &&
+				a_Chunk.UnboundedRelGetBlockType(NeighborPos, BlockType) &&
 				(BlockType == E_BLOCK_AIR)
 			)
 			{
-				// This is an air block next to a fuel next to lava, light it up:
-				a_Chunk.UnboundedRelSetBlock(RelX + CrossCoords[i].x, RelY + CrossCoords[i].y, RelZ + CrossCoords[i].z, E_BLOCK_FIRE, 0);
+				// This is an air block next to a fuel next to lava, light the fuel block up:
+				a_Chunk.UnboundedRelSetBlock(NeighborPos, E_BLOCK_FIRE, 0);
 				return true;
 			}
 		}  // for i - CrossCoords[]
 		return false;
 	}
 
+
+
+
+
 	virtual ColourID GetMapBaseColourID(NIBBLETYPE a_Meta) override
 	{
 		UNUSED(a_Meta);
 		return 4;
 	}
 
+
+
+
+
 	virtual bool CanSustainPlant(BLOCKTYPE a_Plant) override
 	{
 		return false;
diff --git a/src/Blocks/BlockGrass.h b/src/Blocks/BlockGrass.h
index 0e54cb092..374fcceed 100644
--- a/src/Blocks/BlockGrass.h
+++ b/src/Blocks/BlockGrass.h
@@ -39,34 +39,39 @@ public:
 
 
 
-	virtual void OnUpdate(cChunkInterface & cChunkInterface, cWorldInterface & a_WorldInterface, cBlockPluginInterface & a_PluginInterface, cChunk & a_Chunk, int a_RelX, int a_RelY, int a_RelZ) override
+	virtual void OnUpdate(
+		cChunkInterface & a_ChunkInterface,
+		cWorldInterface & a_WorldInterface,
+		cBlockPluginInterface & a_PluginInterface,
+		cChunk & a_Chunk,
+		const Vector3i a_RelPos
+	) override
 	{
-		// Make sure that there is enough light at the source block to spread
 		if (!a_Chunk.GetWorld()->IsChunkLighted(a_Chunk.GetPosX(), a_Chunk.GetPosZ()))
 		{
 			a_Chunk.GetWorld()->QueueLightChunk(a_Chunk.GetPosX(), a_Chunk.GetPosZ());
 			return;
 		}
-		else if ((a_RelY < cChunkDef::Height - 1))
+		auto AbovePos = a_RelPos.addedY(1);
+		if (cChunkDef::IsValidHeight(AbovePos.y))
 		{
-			BLOCKTYPE above = a_Chunk.GetBlock(a_RelX, a_RelY + 1, a_RelZ);
-
-			// Grass turns back to dirt when the block above it is not transparent or water.
-			// It does not turn to dirt when a snow layer is above.
-			if ((above != E_BLOCK_SNOW) &&
-				(!cBlockInfo::IsTransparent(above) || IsBlockWater(above)))
+			// Grass turns back to dirt when the block Above it is not transparent or water.
+			// It does not turn to dirt when a snow layer is Above.
+			auto Above = a_Chunk.GetBlock(AbovePos);
+			if (
+				(Above != E_BLOCK_SNOW) &&
+				(!cBlockInfo::IsTransparent(Above) || IsBlockWater(Above)))
 			{
-				a_Chunk.FastSetBlock(a_RelX, a_RelY, a_RelZ, E_BLOCK_DIRT, E_META_DIRT_NORMAL);
+				a_Chunk.FastSetBlock(a_RelPos, E_BLOCK_DIRT, E_META_DIRT_NORMAL);
 				return;
 			}
 
-			NIBBLETYPE light = std::max(a_Chunk.GetBlockLight(a_RelX, a_RelY + 1, a_RelZ), a_Chunk.GetTimeAlteredLight(a_Chunk.GetSkyLight(a_RelX, a_RelY + 1, a_RelZ)));
-			// Source block is not bright enough to spread
+			// Make sure that there is enough light at the source block to spread
+			auto light = std::max(a_Chunk.GetBlockLight(AbovePos), a_Chunk.GetTimeAlteredLight(a_Chunk.GetSkyLight(AbovePos)));
 			if (light < 9)
 			{
 				return;
 			}
-
 		}
 
 		// Grass spreads to adjacent dirt blocks:
@@ -79,37 +84,36 @@ public:
 
 			BLOCKTYPE  DestBlock;
 			NIBBLETYPE DestMeta;
-			if (!cChunkDef::IsValidHeight(a_RelY + OfsY))
+			auto Pos = a_RelPos + Vector3i(OfsX, OfsY, OfsZ);
+			if (!cChunkDef::IsValidHeight(Pos.y))
 			{
 				// Y Coord out of range
 				continue;
 			}
-			Vector3i pos(a_RelX + OfsX, a_RelY + OfsY, a_RelZ + OfsZ);
-			auto chunk = a_Chunk.GetRelNeighborChunkAdjustCoords(pos);
+			auto chunk = a_Chunk.GetRelNeighborChunkAdjustCoords(Pos);
 			if (chunk == nullptr)
 			{
 				// Unloaded chunk
 				continue;
 			}
-			chunk->GetBlockTypeMeta(pos, DestBlock, DestMeta);
+			chunk->GetBlockTypeMeta(Pos, DestBlock, DestMeta);
 			if ((DestBlock != E_BLOCK_DIRT) || (DestMeta != E_META_DIRT_NORMAL))
 			{
 				// Not a regular dirt block
 				continue;
 			}
-			auto abovePos = pos.addedY(1);
-			BLOCKTYPE above = chunk->GetBlock(abovePos);
-			NIBBLETYPE light = std::max(chunk->GetBlockLight(abovePos), chunk->GetTimeAlteredLight(chunk->GetSkyLight(abovePos)));
+			BLOCKTYPE Above = chunk->GetBlock(AbovePos);
+			NIBBLETYPE light = std::max(chunk->GetBlockLight(AbovePos), chunk->GetTimeAlteredLight(chunk->GetSkyLight(AbovePos)));
 			if ((light > 4)  &&
-				cBlockInfo::IsTransparent(above) &&
-				(!IsBlockLava(above)) &&
-				(!IsBlockWaterOrIce(above))
+				cBlockInfo::IsTransparent(Above) &&
+				(!IsBlockLava(Above)) &&
+				(!IsBlockWaterOrIce(Above))
 			)
 			{
-				auto absPos = chunk->RelativeToAbsolute(pos);
+				auto absPos = chunk->RelativeToAbsolute(Pos);
 				if (!cRoot::Get()->GetPluginManager()->CallHookBlockSpread(*chunk->GetWorld(), absPos.x, absPos.y, absPos.z, ssGrassSpread))
 				{
-					chunk->FastSetBlock(pos, E_BLOCK_GRASS, 0);
+					chunk->FastSetBlock(Pos, E_BLOCK_GRASS, 0);
 				}
 			}
 		}  // for i - repeat twice
diff --git a/src/Blocks/BlockHandler.cpp b/src/Blocks/BlockHandler.cpp
index b3c777b05..f1df4db44 100644
--- a/src/Blocks/BlockHandler.cpp
+++ b/src/Blocks/BlockHandler.cpp
@@ -421,7 +421,13 @@ bool cBlockHandler::GetPlacementBlockTypeMeta(
 
 
 
-void cBlockHandler::OnUpdate(cChunkInterface & cChunkInterface, cWorldInterface & a_WorldInterface, cBlockPluginInterface & a_PluginInterface, cChunk & a_Chunk, int a_BlockX, int a_BlockY, int a_BlockZ)
+void cBlockHandler::OnUpdate(
+	cChunkInterface & a_ChunkInterface,
+	cWorldInterface & a_WorldInterface,
+	cBlockPluginInterface & a_PluginInterface,
+	cChunk & a_Chunk,
+	const Vector3i a_RelPos
+)
 {
 }
 
diff --git a/src/Blocks/BlockHandler.h b/src/Blocks/BlockHandler.h
index 75f6610ce..f4a7fc674 100644
--- a/src/Blocks/BlockHandler.h
+++ b/src/Blocks/BlockHandler.h
@@ -30,8 +30,14 @@ public:
 	virtual ~cBlockHandler() {}
 
 	/** Called when the block gets ticked either by a random tick or by a queued tick.
-	Note that the coords are chunk-relative! */
-	virtual void OnUpdate(cChunkInterface & cChunkInterface, cWorldInterface & a_WorldInterface, cBlockPluginInterface & a_BlockPluginInterface, cChunk & a_Chunk, int a_RelX, int a_RelY, int a_RelZ);
+	Note that the coords in a_RelPos are chunk-relative! */
+	virtual void OnUpdate(
+		cChunkInterface & a_ChunkInterface,
+		cWorldInterface & a_WorldInterface,
+		cBlockPluginInterface & a_BlockPluginInterface,
+		cChunk & a_Chunk,
+		const Vector3i a_RelPos
+	);
 
 	/** Returns the relative bounding box that must be entity-free in
 	order for the block to be placed. a_XM, a_XP, etc. stand for the
@@ -108,7 +114,14 @@ public:
 	static void NeighborChanged(cChunkInterface & a_ChunkInterface, Vector3i a_NeighborPos, eBlockFace a_WhichNeighbor);
 
 	/** Called when the player starts digging the block. */
-	virtual void OnDigging(cChunkInterface & cChunkInterface, cWorldInterface & a_WorldInterface, cPlayer & a_Player, int a_BlockX, int a_BlockY, int a_BlockZ) {}
+	virtual void OnDigging(
+		cChunkInterface & a_ChunkInterface,
+		cWorldInterface & a_WorldInterface,
+		cPlayer & a_Player,
+		int a_BlockX, int a_BlockY, int a_BlockZ
+	)
+	{
+	}
 
 	/** Called if the user right clicks the block and the block is useable
 	returns true if the use was successful, return false to use the block as a "normal" block */
diff --git a/src/Blocks/BlockLeaves.h b/src/Blocks/BlockLeaves.h
index 065c5ec19..c936e0405 100644
--- a/src/Blocks/BlockLeaves.h
+++ b/src/Blocks/BlockLeaves.h
@@ -10,29 +10,88 @@
 // Leaves can be this many blocks that away (inclusive) from the log not to decay
 #define LEAVES_CHECK_DISTANCE 6
 
-#define PROCESS_NEIGHBOR(x, y, z) \
-	do { \
-		switch (a_Area.GetBlockType(x, y, z)) \
-		{ \
-			case E_BLOCK_LEAVES: a_Area.SetBlockType(x, y, z, static_cast<BLOCKTYPE>(E_BLOCK_SPONGE + i + 1)); break; \
-			case E_BLOCK_LOG: return true; \
-			case E_BLOCK_NEW_LEAVES: a_Area.SetBlockType(x, y, z, static_cast<BLOCKTYPE>(E_BLOCK_SPONGE + i + 1)); break; \
-			case E_BLOCK_NEW_LOG: return true; \
-		} \
-	} while (false)
 
-bool HasNearLog(cBlockArea &a_Area, int a_BlockX, int a_BlockY, int a_BlockZ);
 
 
 
-
-
-class cBlockLeavesHandler :
+class cBlockLeavesHandler:
 	public cBlockHandler
 {
+	using Super = cBlockHandler;
+
+	/** Returns true if the area contains a continous path from the specified block to a log block entirely made out of leaves blocks. */
+	static bool HasNearLog(cBlockArea & a_Area, const Vector3i a_BlockPos)
+	{
+		// Filter the blocks into a {leaves, log, other (air)} set:
+		auto * Types = a_Area.GetBlockTypes();
+		for (size_t i = a_Area.GetBlockCount() - 1; i > 0; i--)
+		{
+			switch (Types[i])
+			{
+				case E_BLOCK_LEAVES:
+				case E_BLOCK_LOG:
+				case E_BLOCK_NEW_LEAVES:
+				case E_BLOCK_NEW_LOG:
+				{
+					break;
+				}
+				default:
+				{
+					Types[i] = E_BLOCK_AIR;
+					break;
+				}
+			}
+		}  // for i - Types[]
+
+		// Perform a breadth-first search to see if there's a log connected within 4 blocks of the leaves block:
+		// Simply replace all reachable leaves blocks with a sponge block plus iteration (in the Area) and see if we can reach a log
+		a_Area.SetBlockType(a_BlockPos.x, a_BlockPos.y, a_BlockPos.z, E_BLOCK_SPONGE);
+		for (int i = 0; i < LEAVES_CHECK_DISTANCE; i++)
+		{
+			auto ProcessNeighbor = [&a_Area, i](int cbx, int cby, int cbz) -> bool
+			{
+				switch (a_Area.GetBlockType(cbx, cby, cbz))
+				{
+					case E_BLOCK_LEAVES: a_Area.SetBlockType(cbx, cby, cbz, static_cast<BLOCKTYPE>(E_BLOCK_SPONGE + i + 1)); break;
+					case E_BLOCK_LOG: return true;
+					case E_BLOCK_NEW_LEAVES: a_Area.SetBlockType(cbx, cby, cbz, static_cast<BLOCKTYPE>(E_BLOCK_SPONGE + i + 1)); break;
+					case E_BLOCK_NEW_LOG: return true;
+				}
+				return false;
+			};
+			for (int y = std::max(a_BlockPos.y - i, 0); y <= std::min(a_BlockPos.y + i, cChunkDef::Height - 1); y++)
+			{
+				for (int z = a_BlockPos.z - i; z <= a_BlockPos.z + i; z++)
+				{
+					for (int x = a_BlockPos.x - i; x <= a_BlockPos.x + i; x++)
+					{
+						if (a_Area.GetBlockType(x, y, z) != E_BLOCK_SPONGE + i)
+						{
+							continue;
+						}
+						if (
+							ProcessNeighbor(x - 1, y,     z) ||
+							ProcessNeighbor(x + 1, y,     z) ||
+							ProcessNeighbor(x,     y,     z - 1) ||
+							ProcessNeighbor(x,     y,     z + 1) ||
+							ProcessNeighbor(x,     y + 1, z) ||
+							ProcessNeighbor(x,     y - 1, z)
+						)
+						{
+							return true;
+						}
+					}  // for x
+				}  // for z
+			}  // for y
+		}  // for i - BFS iterations
+		return false;
+	}
+
+
 public:
-	cBlockLeavesHandler(BLOCKTYPE a_BlockType)
-		: cBlockHandler(a_BlockType)
+
+	cBlockLeavesHandler(BLOCKTYPE a_BlockType):
+		Super(a_BlockType)
 	{
 	}
 
@@ -104,30 +163,34 @@ public:
 
 
 
-	virtual void OnUpdate(cChunkInterface & a_ChunkInterface, cWorldInterface & a_WorldInterface, cBlockPluginInterface & a_PluginInterface, cChunk & a_Chunk, int a_RelX, int a_RelY, int a_RelZ) override
+	virtual void OnUpdate(
+		cChunkInterface & a_ChunkInterface,
+		cWorldInterface & a_WorldInterface,
+		cBlockPluginInterface & a_PluginInterface,
+		cChunk & a_Chunk,
+		const Vector3i a_RelPos
+	) override
 	{
-		NIBBLETYPE Meta = a_Chunk.GetMeta(a_RelX, a_RelY, a_RelZ);
+		auto Meta = a_Chunk.GetMeta(a_RelPos);
 		if ((Meta & 0x04) != 0)
 		{
 			// Player-placed leaves, don't decay
 			return;
 		}
 
-		if ((Meta & 0x8) == 0)
+		if ((Meta & 0x08) == 0)
 		{
 			// These leaves have been checked for decay lately and nothing around them changed
 			return;
 		}
 
 		// Get the data around the leaves:
-		int BlockX = a_RelX + a_Chunk.GetPosX() * cChunkDef::Width;
-		int BlockZ = a_RelZ + a_Chunk.GetPosZ() * cChunkDef::Width;
+		auto worldPos = a_Chunk.RelativeToAbsolute(a_RelPos);
 		cBlockArea Area;
 		if (!Area.Read(
 			*a_Chunk.GetWorld(),
-			BlockX - LEAVES_CHECK_DISTANCE, BlockX + LEAVES_CHECK_DISTANCE,
-			a_RelY - LEAVES_CHECK_DISTANCE, a_RelY + LEAVES_CHECK_DISTANCE,
-			BlockZ - LEAVES_CHECK_DISTANCE, BlockZ + LEAVES_CHECK_DISTANCE,
+			worldPos - Vector3i(LEAVES_CHECK_DISTANCE, LEAVES_CHECK_DISTANCE, LEAVES_CHECK_DISTANCE),
+			worldPos + Vector3i(LEAVES_CHECK_DISTANCE, LEAVES_CHECK_DISTANCE, LEAVES_CHECK_DISTANCE),
 			cBlockArea::baTypes)
 		)
 		{
@@ -135,15 +198,15 @@ public:
 			return;
 		}
 
-		if (HasNearLog(Area, BlockX, a_RelY, BlockZ))
+		if (HasNearLog(Area, worldPos))
 		{
 			// Wood found, the leaves stay; unset the check bit
-			a_Chunk.SetMeta(a_RelX, a_RelY, a_RelZ, Meta ^ 0x08, true, false);
+			a_Chunk.SetMeta(a_RelPos, Meta ^ 0x08, true, false);
 			return;
 		}
 
 		// Decay the leaves:
-		a_ChunkInterface.DropBlockAsPickups({BlockX, a_RelY, BlockZ});
+		a_ChunkInterface.DropBlockAsPickups(worldPos);
 	}
 
 
@@ -156,62 +219,3 @@ public:
 		return 7;
 	}
 } ;
-
-
-
-
-
-bool HasNearLog(cBlockArea & a_Area, int a_BlockX, int a_BlockY, int a_BlockZ)
-{
-	// Filter the blocks into a {leaves, log, other (air)} set:
-	BLOCKTYPE * Types = a_Area.GetBlockTypes();
-	for (size_t i = a_Area.GetBlockCount() - 1; i > 0; i--)
-	{
-		switch (Types[i])
-		{
-			case E_BLOCK_LEAVES:
-			case E_BLOCK_LOG:
-			case E_BLOCK_NEW_LEAVES:
-			case E_BLOCK_NEW_LOG:
-			{
-				break;
-			}
-			default:
-			{
-				Types[i] = E_BLOCK_AIR;
-				break;
-			}
-		}
-	}  // for i - Types[]
-
-	// Perform a breadth-first search to see if there's a log connected within 4 blocks of the leaves block:
-	// Simply replace all reachable leaves blocks with a sponge block plus iteration (in the Area) and see if we can reach a log in 4 iterations
-	a_Area.SetBlockType(a_BlockX, a_BlockY, a_BlockZ, E_BLOCK_SPONGE);
-	for (int i = 0; i < LEAVES_CHECK_DISTANCE; i++)
-	{
-		for (int y = std::max(a_BlockY - i, 0); y <= std::min(a_BlockY + i, cChunkDef::Height - 1); y++)
-		{
-			for (int z = a_BlockZ - i; z <= a_BlockZ + i; z++)
-			{
-				for (int x = a_BlockX - i; x <= a_BlockX + i; x++)
-				{
-					if (a_Area.GetBlockType(x, y, z) != E_BLOCK_SPONGE + i)
-					{
-						continue;
-					}
-					PROCESS_NEIGHBOR(x - 1, y,     z);
-					PROCESS_NEIGHBOR(x + 1, y,     z);
-					PROCESS_NEIGHBOR(x,     y,     z - 1);
-					PROCESS_NEIGHBOR(x,     y,     z + 1);
-					PROCESS_NEIGHBOR(x,     y + 1, z);
-					PROCESS_NEIGHBOR(x,     y - 1, z);
-				}  // for x
-			}  // for z
-		}  // for y
-	}  // for i - BFS iterations
-	return false;
-}
-
-
-
-
diff --git a/src/Blocks/BlockPlant.h b/src/Blocks/BlockPlant.h
index 589619b26..b0760528c 100644
--- a/src/Blocks/BlockPlant.h
+++ b/src/Blocks/BlockPlant.h
@@ -26,20 +26,25 @@ public:
 
 
 
-	virtual void OnUpdate(cChunkInterface & a_ChunkInterface, cWorldInterface & a_WorldInterface, cBlockPluginInterface & a_PluginInterface, cChunk & a_Chunk, int a_RelX, int a_RelY, int a_RelZ) override
+	virtual void OnUpdate(
+		cChunkInterface & a_ChunkInterface,
+		cWorldInterface & a_WorldInterface,
+		cBlockPluginInterface & a_PluginInterface,
+		cChunk & a_Chunk,
+		const Vector3i a_RelPos
+	) override
 	{
-		Vector3i relPos(a_RelX, a_RelY, a_RelZ);
-		auto action = CanGrow(a_Chunk, relPos);
-		switch (action)
+		auto Action = CanGrow(a_Chunk, a_RelPos);
+		switch (Action)
 		{
 			case paGrowth:
 			{
-				Grow(a_Chunk, relPos);
+				Grow(a_Chunk, a_RelPos);
 				break;
 			}
 			case paDeath:
 			{
-				a_ChunkInterface.DigBlock(a_WorldInterface, a_Chunk.RelativeToAbsolute(relPos));
+				a_ChunkInterface.DigBlock(a_WorldInterface, a_Chunk.RelativeToAbsolute(a_RelPos));
 				break;
 			}
 			case paStay: break;  // do nothing
diff --git a/src/Blocks/BlockPortal.h b/src/Blocks/BlockPortal.h
index 852a231b6..3f5d87155 100644
--- a/src/Blocks/BlockPortal.h
+++ b/src/Blocks/BlockPortal.h
@@ -46,18 +46,26 @@ public:
 
 
 
-	virtual void OnUpdate(cChunkInterface & cChunkInterface, cWorldInterface & a_WorldInterface, cBlockPluginInterface & a_PluginInterface, cChunk & a_Chunk, int a_RelX, int a_RelY, int a_RelZ) override
+	virtual void OnUpdate(
+		cChunkInterface & a_ChunkInterface,
+		cWorldInterface & a_WorldInterface,
+		cBlockPluginInterface & a_PluginInterface,
+		cChunk & a_Chunk,
+		const Vector3i a_RelPos
+	) override
 	{
+		// Spawn zombie pigmen with a 0.05% chance:
 		if (GetRandomProvider().RandBool(0.9995))
 		{
 			return;
 		}
+		auto WorldPos = a_Chunk.RelativeToAbsolute(a_RelPos);
+		a_WorldInterface.SpawnMob(WorldPos.x, WorldPos.y, WorldPos.z, mtZombiePigman, false);
+	}
+
+
 
-		int PosX = a_Chunk.GetPosX() * cChunkDef::Width + a_RelX;
-		int PosZ = a_Chunk.GetPosZ() * cChunkDef::Width + a_RelZ;
 
-		a_WorldInterface.SpawnMob(PosX, a_RelY, PosZ, mtZombiePigman, false);
-	}
 
 	virtual bool CanBeAt(cChunkInterface & a_ChunkInterface, int a_RelX, int a_RelY, int a_RelZ, const cChunk & a_Chunk) override
 	{
diff --git a/src/Blocks/BlockRedstoneOre.h b/src/Blocks/BlockRedstoneOre.h
index cb6f73733..4b570ab73 100644
--- a/src/Blocks/BlockRedstoneOre.h
+++ b/src/Blocks/BlockRedstoneOre.h
@@ -12,9 +12,10 @@ class cBlockRedstoneOreHandler :
 	public cBlockOreHandler
 {
 	using Super = cBlockOreHandler;
+
 public:
 
-	using Super::Super;
+	using Super::Super;  // Inherit constructor from base
 
 	virtual bool OnUse(
 		cChunkInterface & a_ChunkInterface,
@@ -55,19 +56,19 @@ class cBlockGlowingRedstoneOreHandler:
 	public cBlockOreHandler
 {
 	using Super = cBlockOreHandler;
+
 public:
 
-	using Super::Super;
+	using Super::Super;  // Inherit constructor from base
 
 	virtual void OnUpdate(
 		cChunkInterface & a_ChunkInterface,
 		cWorldInterface & a_WorldInterface,
 		cBlockPluginInterface & a_BlockPluginInterface,
 		cChunk & a_Chunk,
-		int a_RelX, int a_RelY, int a_RelZ
+		const Vector3i a_RelPos
 	) override
 	{
-		const Vector3i a_RelPos{a_RelX, a_RelY, a_RelZ};
 		auto BlockPos = a_Chunk.RelativeToAbsolute(a_RelPos);
 		a_ChunkInterface.SetBlock(BlockPos, E_BLOCK_REDSTONE_ORE, 0);
 	}
diff --git a/src/Blocks/BlockSapling.h b/src/Blocks/BlockSapling.h
index b66587288..370353882 100644
--- a/src/Blocks/BlockSapling.h
+++ b/src/Blocks/BlockSapling.h
@@ -43,26 +43,31 @@ public:
 
 
 
-	virtual void OnUpdate(cChunkInterface & cChunkInterface, cWorldInterface & a_WorldInterface, cBlockPluginInterface & a_PluginInterface, cChunk & a_Chunk, int a_RelX, int a_RelY, int a_RelZ) override
+	virtual void OnUpdate(
+		cChunkInterface & a_ChunkInterface,
+		cWorldInterface & a_WorldInterface,
+		cBlockPluginInterface & a_PluginInterface,
+		cChunk & a_Chunk,
+		const Vector3i a_RelPos
+	) override
 	{
-		NIBBLETYPE Meta = a_Chunk.GetMeta(a_RelX, a_RelY, a_RelZ);
-		NIBBLETYPE Light = std::max(a_Chunk.GetBlockLight(a_RelX, a_RelY, a_RelZ), a_Chunk.GetTimeAlteredLight(a_Chunk.GetSkyLight(a_RelX, a_RelY, a_RelZ)));
+		auto Meta = a_Chunk.GetMeta(a_RelPos);
+		auto Light = std::max(a_Chunk.GetBlockLight(a_RelPos), a_Chunk.GetTimeAlteredLight(a_Chunk.GetSkyLight(a_RelPos)));
 
 		// Only grow if we have the right amount of light
 		if (Light > 8)
 		{
 			auto & random = GetRandomProvider();
 			// Only grow if we are in the right growth stage and have the right amount of space around them.
-			if (((Meta & 0x08) != 0) && random.RandBool(0.45) && CanGrowAt(a_Chunk, a_RelX, a_RelY, a_RelZ, Meta))
+			if (((Meta & 0x08) != 0) && random.RandBool(0.45) && CanGrowAt(a_Chunk, a_RelPos.x, a_RelPos.y, a_RelPos.z, Meta))
 			{
-				int BlockX = a_RelX + a_Chunk.GetPosX() * cChunkDef::Width;
-				int BlockZ = a_RelZ + a_Chunk.GetPosZ() * cChunkDef::Width;
-				a_Chunk.GetWorld()->GrowTree(BlockX, a_RelY, BlockZ);
+				auto WorldPos = a_Chunk.RelativeToAbsolute(a_RelPos);
+				a_Chunk.GetWorld()->GrowTree(WorldPos.x, WorldPos.y, WorldPos.z);
 			}
 			// Only move to the next growth stage if we haven't gone there yet
 			else if (((Meta & 0x08) == 0) && random.RandBool(0.45))
 			{
-				a_Chunk.SetMeta(a_RelX, a_RelY, a_RelZ, Meta | 0x08);
+				a_Chunk.SetMeta(a_RelPos, Meta | 0x08);
 			}
 		}
 	}
diff --git a/src/Blocks/BlockVine.h b/src/Blocks/BlockVine.h
index 9c3c1c53e..f8328f046 100644
--- a/src/Blocks/BlockVine.h
+++ b/src/Blocks/BlockVine.h
@@ -221,25 +221,33 @@ public:
 
 
 
-	virtual void OnUpdate(cChunkInterface & a_ChunkInterface, cWorldInterface & a_WorldInterface, cBlockPluginInterface & a_BlockPluginInterface, cChunk & a_Chunk, int a_RelX, int a_RelY, int a_RelZ) override
+	virtual void OnUpdate(
+		cChunkInterface & a_ChunkInterface,
+		cWorldInterface & a_WorldInterface,
+		cBlockPluginInterface & a_PluginInterface,
+		cChunk & a_Chunk,
+		const Vector3i a_RelPos
+	) override
 	{
 		UNUSED(a_ChunkInterface);
 		UNUSED(a_WorldInterface);
 
 		// Vine cannot grow down if at the bottom:
-		if (a_RelY < 1)
+		auto GrowPos = a_RelPos.addedY(-1);
+		if (!cChunkDef::IsValidHeight(GrowPos.y))
 		{
 			return;
 		}
 
 		// Grow one block down, if possible:
 		BLOCKTYPE Block;
-		a_Chunk.UnboundedRelGetBlockType(a_RelX, a_RelY - 1, a_RelZ, Block);
+		a_Chunk.UnboundedRelGetBlockType(GrowPos, Block);
 		if (Block == E_BLOCK_AIR)
 		{
-			if (!a_BlockPluginInterface.CallHookBlockSpread(a_RelX + a_Chunk.GetPosX() * cChunkDef::Width, a_RelY - 1, a_RelZ + a_Chunk.GetPosZ() * cChunkDef::Width, ssVineSpread))
+			auto WorldPos = a_Chunk.RelativeToAbsolute(GrowPos);
+			if (!a_PluginInterface.CallHookBlockSpread(WorldPos.x, WorldPos.y, WorldPos.z, ssVineSpread))
 			{
-				a_Chunk.UnboundedRelSetBlock(a_RelX, a_RelY - 1, a_RelZ, E_BLOCK_VINES, a_Chunk.GetMeta(a_RelX, a_RelY, a_RelZ));
+				a_Chunk.UnboundedRelSetBlock(GrowPos, E_BLOCK_VINES, a_Chunk.GetMeta(a_RelPos));
 			}
 		}
 	}
diff --git a/src/Blocks/CMakeLists.txt b/src/Blocks/CMakeLists.txt
index 24d0a20a6..dea14b7f1 100644
--- a/src/Blocks/CMakeLists.txt
+++ b/src/Blocks/CMakeLists.txt
@@ -47,6 +47,7 @@ SET (HDRS
 	BlockFurnace.h
 	BlockGlass.h
 	BlockGlowstone.h
+	BlockGrass.h
 	BlockGravel.h
 	BlockHandler.h
 	BlockHopper.h
diff --git a/src/Blocks/WorldInterface.h b/src/Blocks/WorldInterface.h
index b4dcfa4a9..0967e2bb8 100644
--- a/src/Blocks/WorldInterface.h
+++ b/src/Blocks/WorldInterface.h
@@ -73,6 +73,10 @@ public:
 	/** Returns true if it is raining or storming at the specified location. This takes into account biomes. */
 	virtual bool IsWeatherWetAt(int a_BlockX, int a_BlockZ) = 0;
 
+	/** Returns true if it is raining or storming at the specified location,
+	and the rain reaches the specified block position. */
+	virtual bool IsWeatherWetAtXYZ(Vector3i a_Pos) = 0;
+
 	/** Returns or sets the minumim or maximum netherportal width */
 	virtual int GetMinNetherPortalWidth(void) const = 0;
 	virtual int GetMaxNetherPortalWidth(void) const = 0;