text: 
  #pragma once
  
  #include "Simulator.h"
  
  
  
  
  
  // fwd:
  class cChunk;
  
  
  
  
  
  /** Per-chunk data for the simulator, specified individual chunks to simulate; Data is not used */
  typedef cCoordWithIntList cSandSimulatorChunkData;
  
  
  
  
  
  /** 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, cIniFile & a_IniFile);
  
  	// cSimulator overrides:
  	virtual void Simulate(float a_Dt) override { UNUSED(a_Dt);}  // not used
  	virtual void SimulateChunk(std::chrono::milliseconds 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, NIBBLETYPE a_BlockMeta);
  
  	/** 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;
  
  	/** 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);
  };
  
  
  
  
  
  
  
  
  
  