2 files changed, 232 insertions, 61 deletions

diff --git a/source/Simulator/SandSimulator.cpp b/source/Simulator/SandSimulator.cpp
index 04bcc498c..27e137354 100644
--- a/source/Simulator/SandSimulator.cpp
+++ b/source/Simulator/SandSimulator.cpp
@@ -12,102 +12,243 @@
 
 
 
-cSandSimulator::cSandSimulator(cWorld & a_World)
-	: cSimulator(a_World)
-	, m_Blocks(new BlockList)
-	, m_Buffer(new BlockList)
+cSandSimulator::cSandSimulator(cWorld & a_World, cIniFile & a_IniFile) :
+	cSimulator(a_World),
+	m_TotalBlocks(0)
 {
+	m_IsInstantFall = a_IniFile.GetValueSetB("Physics", "SandInstantFall", false);
+}
+
+
+
+
+
+void cSandSimulator::SimulateChunk(float a_Dt, int a_ChunkX, int a_ChunkZ, cChunk * a_Chunk)
+{
+	cSandSimulatorChunkData & ChunkData = a_Chunk->GetSandSimulatorData();
+	if (ChunkData.empty())
+	{
+		return;
+	}
 
+	int BaseX = a_Chunk->GetPosX() * cChunkDef::Width;
+	int BaseZ = a_Chunk->GetPosZ() * cChunkDef::Width;
+	for (cSandSimulatorChunkData::const_iterator itr = ChunkData.begin(), end = ChunkData.end(); itr != end; ++itr)
+	{
+		BLOCKTYPE BlockType = a_Chunk->GetBlock(itr->x, itr->y, itr->z);
+		if (!IsAllowedBlock(BlockType) || (itr->y <= 0))
+		{
+			continue;
+		}
+
+		BLOCKTYPE BlockBelow = (itr->y > 0) ? a_Chunk->GetBlock(itr->x, itr->y - 1, itr->z) : E_BLOCK_AIR;
+		if (CanStartFallingThrough(BlockBelow))
+		{
+			if (m_IsInstantFall)
+			{
+				DoInstantFall(a_Chunk, itr->x, itr->y, itr->z);
+				continue;
+			}
+			Vector3i Pos;
+			Pos.x = itr->x + BaseX;
+			Pos.y = itr->y;
+			Pos.z = itr->z + BaseZ;
+			cFallingBlock * FallingBlock = new cFallingBlock(Pos, BlockType, a_Chunk->GetMeta(itr->x, itr->y, itr->z));
+			FallingBlock->Initialize(&m_World);
+			a_Chunk->SetBlock(itr->x, itr->y, itr->z, E_BLOCK_AIR, 0);
+		}
+	}
+	m_TotalBlocks -= ChunkData.size();
+	ChunkData.clear();
 }
 
 
 
 
 
-cSandSimulator::~cSandSimulator()
+bool cSandSimulator::IsAllowedBlock(BLOCKTYPE a_BlockType)
 {
-	delete m_Buffer;
-	delete m_Blocks;
+	switch (a_BlockType)
+	{
+		case E_BLOCK_SAND:
+		case E_BLOCK_GRAVEL:
+		case E_BLOCK_ANVIL:
+		{
+			return true;
+		}
+	}
+	return false;
 }
 
 
 
 
 
-void cSandSimulator::Simulate(float a_Dt)
+void cSandSimulator::AddBlock(int a_BlockX, int a_BlockY, int a_BlockZ, cChunk * a_Chunk)
 {
-	m_Buffer->clear();
-	std::swap( m_Blocks, m_Buffer );
+	if (a_Chunk == NULL)
+	{
+		return;
+	}
+	int RelX = a_BlockX - a_Chunk->GetPosX() * cChunkDef::Width;
+	int RelZ = a_BlockZ - a_Chunk->GetPosZ() * cChunkDef::Width;
+	if (!IsAllowedBlock(a_Chunk->GetBlock(RelX, a_BlockY, RelZ)))
+	{
+		return;
+	}
 
-	for( BlockList::iterator itr = m_Buffer->begin(); itr != m_Buffer->end(); ++itr )
+	// Check for duplicates:
+	cSandSimulatorChunkData & ChunkData = a_Chunk->GetSandSimulatorData();
+	for (cSandSimulatorChunkData::iterator itr = ChunkData.begin(); itr != ChunkData.end(); ++itr)
 	{
-		Vector3i Pos = *itr;
-		BLOCKTYPE BlockID = m_World.GetBlock(Pos.x, Pos.y, Pos.z);
-		if(!IsAllowedBlock(BlockID))
-			continue;
+		if ((itr->x == RelX) && (itr->y == a_BlockY) && (itr->z == a_BlockZ))
+		{
+			return;
+		}
+	}
+
+	m_TotalBlocks += 1;
+	ChunkData.push_back(cCoordWithInt(RelX, a_BlockY, RelZ));
+}
+
 
-		BLOCKTYPE BottomBlock = m_World.GetBlock( Pos.x, Pos.y - 1, Pos.z );
-		
-		if( IsPassable(BottomBlock) )
+
+
+
+bool cSandSimulator::CanStartFallingThrough(BLOCKTYPE a_BlockType)
+{
+	switch (a_BlockType)
+	{
+		case E_BLOCK_AIR:
+		case E_BLOCK_FIRE:
+		case E_BLOCK_WATER:
+		case E_BLOCK_STATIONARY_WATER:
+		case E_BLOCK_LAVA:
+		case E_BLOCK_STATIONARY_LAVA:
 		{
-			cFallingBlock * FallingBlock = new cFallingBlock(Pos, BlockID);
-			FallingBlock->Initialize(&m_World);
- 			m_World.SetBlock( Pos.x, Pos.y, Pos.z, E_BLOCK_AIR, 0 );
+			return true;
 		}
 	}
-		
+	return false;
 }
 
 
 
 
 
-bool cSandSimulator::IsAllowedBlock( BLOCKTYPE a_BlockType )
+bool cSandSimulator::CanContinueFallThrough(BLOCKTYPE a_BlockType)
 {
-	return a_BlockType == E_BLOCK_SAND
-		|| a_BlockType == E_BLOCK_GRAVEL;
+	switch (a_BlockType)
+	{
+		case E_BLOCK_AIR:
+		case E_BLOCK_FIRE:
+		case E_BLOCK_WATER:
+		case E_BLOCK_STATIONARY_WATER:
+		case E_BLOCK_LAVA:
+		case E_BLOCK_STATIONARY_LAVA:
+		case E_BLOCK_POWERED_RAIL:
+		case E_BLOCK_DETECTOR_RAIL:
+		case E_BLOCK_COBWEB:
+		case E_BLOCK_TALL_GRASS:
+		case E_BLOCK_DEAD_BUSH:
+		case E_BLOCK_YELLOW_FLOWER:
+		case E_BLOCK_RED_ROSE:
+		case E_BLOCK_BROWN_MUSHROOM:
+		case E_BLOCK_RED_MUSHROOM:
+		case E_BLOCK_TORCH:
+		case E_BLOCK_REDSTONE_WIRE:
+		case E_BLOCK_CROPS:
+		case E_BLOCK_PUMPKIN_STEM:
+		case E_BLOCK_MELON_STEM:
+		case E_BLOCK_REDSTONE_TORCH_OFF:
+		case E_BLOCK_REDSTONE_TORCH_ON:
+		case E_BLOCK_STONE_BUTTON:
+		case E_BLOCK_STONE_PRESSURE_PLATE:
+		case E_BLOCK_WOODEN_BUTTON:
+		case E_BLOCK_WOODEN_PRESSURE_PLATE:
+		case E_BLOCK_REDSTONE_REPEATER_OFF:
+		case E_BLOCK_REDSTONE_REPEATER_ON:
+		{
+			return true;
+		}
+	}
+	return false;
 }
 
 
 
 
 
-void cSandSimulator::AddBlock(int a_BlockX, int a_BlockY, int a_BlockZ, cChunk * a_Chunk)
+bool cSandSimulator::IsReplacedOnRematerialization(BLOCKTYPE a_BlockType)
 {
-	// TODO: Optimize this by passing the block type along
-	int RelX = a_BlockX;
-	int RelY = a_BlockY;
-	int RelZ = a_BlockZ;
-	int ChunkX, ChunkZ;
-	cChunkDef::AbsoluteToRelative(RelX, RelY, RelZ, ChunkX, ChunkZ);
-	if (!IsAllowedBlock(a_Chunk->GetBlock(RelX, RelY, RelZ)))
+	switch (a_BlockType)
 	{
-		return;
+		case E_BLOCK_AIR:
+		case E_BLOCK_FIRE:
+		case E_BLOCK_WATER:
+		case E_BLOCK_STATIONARY_WATER:
+		case E_BLOCK_LAVA:
+		case E_BLOCK_STATIONARY_LAVA:
+		case E_BLOCK_TALL_GRASS:
+		case E_BLOCK_DEAD_BUSH:
+		{
+			return true;
+		}
 	}
+	return false;
+}
 
-	Vector3i Block(a_BlockX, a_BlockY, a_BlockZ);
-	
-	//check for duplicates
-	for (BlockList::iterator itr = m_Blocks->begin(); itr != m_Blocks->end(); ++itr)
+
+
+
+
+bool cSandSimulator::DoesBreakFallingThrough(BLOCKTYPE a_BlockType)
+{
+	switch (a_BlockType)
 	{
-		Vector3i Pos = *itr;
-		if ((Pos.x == a_BlockX) && (Pos.y == a_BlockY) && (Pos.z == a_BlockZ))
+		case E_BLOCK_STONE_SLAB:
+		case E_BLOCK_WOODEN_SLAB:
 		{
-			return;
+			return true;
 		}
 	}
+	return false;
+}
+
 
-	m_Blocks->push_back(Block);
+
+
+
+void cSandSimulator::FinishFalling(
+	cWorld * a_World, int a_BlockX, int a_BlockY, int a_BlockZ,
+	BLOCKTYPE a_FallingBlockType, NIBBLETYPE a_FallingBlockMeta
+)
+{
+	ASSERT(a_BlockY < cChunkDef::Height);
+	
+	BLOCKTYPE CurrentBlockType = a_World->GetBlock(a_BlockX, a_BlockY, a_BlockZ);
+	if ((a_FallingBlockType == E_BLOCK_ANVIL) || IsReplacedOnRematerialization(CurrentBlockType))
+	{
+		// Rematerialize the material here:
+		a_World->SetBlock(a_BlockX, a_BlockY, a_BlockZ, a_FallingBlockType, a_FallingBlockMeta);
+		return;
+	}
+	
+	// Create a pickup instead:
+	cItems Pickups;
+	Pickups.Add((ENUM_ITEM_ID)a_FallingBlockType, 1, a_FallingBlockMeta);
+	a_World->SpawnItemPickups(Pickups, (double)a_BlockX + 0.5, (double)a_BlockY + 0.5, (double)a_BlockZ + 0.5, 0);
 }
 
 
 
 
 
-bool cSandSimulator::IsPassable(BLOCKTYPE a_BlockType)
+void cSandSimulator::DoInstantFall(cChunk * a_Chunk, int a_RelX, int a_RelY, int a_RelZ)
 {
-	return (a_BlockType == E_BLOCK_AIR)
-		|| IsBlockWater(a_BlockType)
-		|| IsBlockLava(a_BlockType)
-		|| (a_BlockType == E_BLOCK_FIRE);
+	// TODO
 }
+
+
+
+
diff --git a/source/Simulator/SandSimulator.h b/source/Simulator/SandSimulator.h
index ebd154f2d..571258049 100644
--- a/source/Simulator/SandSimulator.h
+++ b/source/Simulator/SandSimulator.h
@@ -2,32 +2,62 @@
 #pragma once
 
 #include "Simulator.h"
-#include "../BlockEntity.h"
-#include "../Vector3i.h"
 
 
 
 
 
-class cSandSimulator : public cSimulator
+/// Despite the class name, this simulator takes care of all blocks that fall when suspended in the air.
+class cSandSimulator :
+	public cSimulator
 {
 public:
-	cSandSimulator(cWorld & a_World);
-	~cSandSimulator();
-
-	virtual void Simulate( float a_Dt ) override;
-
-	virtual bool IsAllowedBlock( BLOCKTYPE a_BlockType ) override;
-	virtual bool IsPassable( BLOCKTYPE a_BlockType );
+	cSandSimulator(cWorld & a_World, cIniFile & a_IniFile);
+
+	// cSimulator overrides:
+	virtual void Simulate(float a_Dt) override {}  // Unused in this simulator
+	virtual void SimulateChunk(float a_Dt, int a_ChunkX, int a_ChunkZ, cChunk * a_Chunk) override;
+	virtual bool IsAllowedBlock(BLOCKTYPE a_BlockType) override;
+	
+	/// Returns true if a falling-able block can start falling through the specified block type
+	static bool CanStartFallingThrough(BLOCKTYPE a_BlockType);
+	
+	/// Returns true if an already-falling block can pass through the specified block type (e. g. torch)
+	static bool CanContinueFallThrough(BLOCKTYPE a_BlockType);
+	
+	/// Returns true if the falling block rematerializing will replace the specified block type (e. g. tall grass)
+	static bool IsReplacedOnRematerialization(BLOCKTYPE a_BlockType);
+	
+	/// Returns true if the specified block breaks falling blocks while they fall through it (e. g. halfslabs)
+	static bool DoesBreakFallingThrough(BLOCKTYPE a_BlockType);
+	
+	/** Called when a block finishes falling at the specified coords, either by insta-fall,
+	or through cFallingBlock entity.
+	It either rematerializes the block (a_FallingBlockType) at the specified coords, or creates a pickup,
+	based on the block currently present in the world at the dest specified coords
+	*/
+	static void FinishFalling(
+		cWorld * a_World, int a_BlockX, int a_BlockY, int a_BlockZ, 
+		BLOCKTYPE a_FallingBlockType, NIBBLETYPE a_FallingBlockMeta
+	);
 
 protected:
+	bool m_IsInstantFall;  // If set to true, blocks don't fall using cFallingBlock entity, but instantly instead
+	
+	int  m_TotalBlocks;    // Total number of blocks currently in the queue for simulating
+	
 	virtual void AddBlock(int a_BlockX, int a_BlockY, int a_BlockZ, cChunk * a_Chunk) override;
-
-	typedef std::list <Vector3i> BlockList;
-	BlockList * m_Blocks;
-	BlockList * m_Buffer;
+	
+	/// Performs the instant fall of the block - removes it from top, Finishes it at the bottom
+	void DoInstantFall(cChunk * a_Chunk, int a_RelX, int a_RelY, int a_RelZ);
 };
 
 
 
 
+/// Per-chunk data for the simulator, specified individual chunks to simulate; Data is not used
+typedef cCoordWithIntList cSandSimulatorChunkData;
+
+
+
+