1 files changed, 109 insertions, 31 deletions

diff --git a/source/cChunk.cpp b/source/cChunk.cpp
index ff1f7472b..6c9165b30 100644
--- a/source/cChunk.cpp
+++ b/source/cChunk.cpp
@@ -27,6 +27,8 @@
 #include "cBlockToPickup.h"
 #include "MersenneTwister.h"
 #include "cPlayer.h"
+#include "BlockArea.h"
+#include "cPluginManager.h"
 
 #include "packets/cPacket_DestroyEntity.h"
 #include "packets/cPacket_PreChunk.h"
@@ -39,6 +41,13 @@
 
 
 
+// Leaves can be this many blocks that away from the log not to decay
+#define LEAVES_CHECK_DISTANCE 4
+
+
+
+
+
 extern bool g_bWaterPhysics;
 
 
@@ -515,6 +524,13 @@ void cChunk::CheckBlocks(void)
 				}
 				break;
 			}
+			
+			// If anything next to a leaves block changes, set the leaves' "check for decay" bit (clear bit 0x08):
+			case E_BLOCK_LEAVES:
+			{
+				cChunkDef::SetNibble(m_BlockMeta, index, BlockMeta & 0x07);
+				break;
+			}
 		}  // switch (BlockType)
 	}  // for itr - ToTickBlocks[]
 }
@@ -591,7 +607,7 @@ void cChunk::TickBlocks(MTRand & a_TickRandom)
 				break;
 			}
 			
-			case E_BLOCK_LEAVES: TickLeaves(m_BlockTickX, m_BlockTickY, m_BlockTickZ); break;
+			case E_BLOCK_LEAVES: TickLeaves(m_BlockTickX, m_BlockTickY, m_BlockTickZ, a_TickRandom); break;
 			
 			default:
 			{
@@ -746,53 +762,115 @@ void cChunk::TickFarmland(int a_RelX, int a_RelY, int a_RelZ)
 
 
 
-void cChunk::TickLeaves(int a_RelX, int a_RelY, int a_RelZ)
+void cChunk::TickLeaves(int a_RelX, int a_RelY, int a_RelZ, MTRand & a_TickRandom)
 {
 	// Since leaves-checking is a costly operation, it is done only if leaves are marked for checking (Meta has its 0x08 bit cleared)
-	// TODO: The meta is cleared (check flag set) each time a block next to the leaves changes
+	// The meta bit 0x08 bit is cleared (check flag set) each time a block next to the leaves changes
 	
-	NIBBLETYPE Meta = GetMeta(m_BlockTickX, m_BlockTickY, m_BlockTickZ);
+	NIBBLETYPE Meta = GetMeta(a_RelX, a_RelY, a_RelZ);
 	if ((Meta & 0x04) != 0)
 	{
 		// Player-placed leaves, don't decay
 		return;
 	}
-	if ((Meta & 0x08) == 0)
+	if ((Meta & 0x08) != 0)
 	{
 		// These leaves have been checked for decay lately and nothing around them changed
 		return;
 	}
-	
-	// TODO: We need a proper BFS check - is the leaves block connected to a log via other leaves blocks?
-	for (int y = 4; y > - 5; y--)
+
+	// Get the data around the leaves:
+	cBlockArea Area;
+	int BaseX = cChunkDef::Width * m_PosX + a_RelX;
+	int BaseZ = cChunkDef::Width * m_PosZ + a_RelZ;
+	if (!Area.Read(
+		m_World, 
+		BaseX - LEAVES_CHECK_DISTANCE, BaseX + LEAVES_CHECK_DISTANCE, 
+		a_RelY - LEAVES_CHECK_DISTANCE, a_RelY + LEAVES_CHECK_DISTANCE, 
+		BaseZ - LEAVES_CHECK_DISTANCE, BaseZ + LEAVES_CHECK_DISTANCE, 
+		cBlockArea::baTypes)
+	)
 	{
-		for (int z = - 4; z < 5; z++ )
+		// Cannot check leaves, a chunk is missing too close
+		return;
+	}
+
+	if (HasNearLog(Area, BaseX, a_RelY, BaseZ))
+	{
+		// Wood found, the leaves stay; mark them as checked:
+		SetNibble(m_BlockMeta, a_RelX, a_RelY, a_RelZ, Meta & 0x07);
+		return;
+	}
+	// Decay the leaves:
+	m_World->DigBlock(m_PosX * cChunkDef::Width + a_RelX, a_RelY, m_PosZ * cChunkDef::Width + a_RelZ);
+
+	// Let them drop something if the random is right:
+	cItems PickupItems;
+	cBlockToPickup::ToPickup(E_BLOCK_LEAVES, Meta, cItem(), PickupItems);
+		
+	// Allow plugins to change the dropped objects:
+	cRoot::Get()->GetPluginManager()->CallHookBlockToPickup(E_BLOCK_LEAVES, Meta, NULL, cItem(), PickupItems);
+	m_World->SpawnItemPickups(PickupItems, BaseX, a_RelY, BaseZ);
+}
+
+
+
+
+
+#define PROCESS_NEIGHBOR(x,y,z) \
+	switch (a_Area.GetBlockType(x, y, z)) \
+	{ \
+		case E_BLOCK_LEAVES: a_Area.SetBlockType(x, y, z, E_BLOCK_SPONGE + i + 1); break; \
+		case E_BLOCK_LOG: return true; \
+	}
+
+bool cChunk::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 (int i = a_Area.GetBlockCount() - 1; i > 0; i--)
+	{
+		switch (Types[i])
 		{
-			for (int x = - 4; x < 5; x++ )
+			case E_BLOCK_LEAVES:
+			case E_BLOCK_LOG:
 			{
-				if (abs(x) + abs(y) + abs(z) > 4)
-				{
-					// Too far away
-					continue;
-				}
-				BLOCKTYPE  BlockType;
-				NIBBLETYPE BlockMeta;
-				if (!UnboundedRelGetBlock(a_RelX + x, a_RelY + y, a_RelZ + z, BlockType, BlockMeta))
-				{
-					// Too close to unloaded chunks, don't check at all
-					return;
-				} 
-				if (BlockType == E_BLOCK_LOG)
-				{
-					// Wood found, the leaves stay; mark them as checked:
-					SetNibble(m_BlockMeta, a_RelX, a_RelY, a_RelZ, Meta & 0x07);
-					return;
-				}
+				break;
+			}
+			default:
+			{
+				Types[i] = E_BLOCK_AIR;
+				break;
 			}
 		}
-	}
-	// Decay the leaves. Let them drop something if the random is right
-	m_World->DigBlock(m_PosX * cChunkDef::Width + a_RelX, a_RelY, m_PosZ * cChunkDef::Width + a_RelZ);
+	}  // 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 = a_BlockY - i; y <= a_BlockY + i; 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;
 }