path: root/src/BlockEntities/BlockEntity.h

#pragma once





/** Place this macro in the declaration of each cBlockEntity descendant. */
#define BLOCKENTITY_PROTODEF(classname) \
	virtual bool IsA(const char * a_ClassName) const override \
	{ \
		return ((a_ClassName != nullptr) && ((strcmp(a_ClassName, #classname) == 0) || Super::IsA(a_ClassName))); \
	} \
	virtual const char * GetClass() const override \
	{ \
		return #classname; \
	} \
	static const char * GetClassStatic() \
	{ \
		return #classname; \
	} \
	virtual const char * GetParentClass() const override \
	{ \
		return Super::GetClass(); \
	}





class cChunk;
class cItems;
class cPlayer;
class cWorld;
class cBlockEntity;

using OwnedBlockEntity = std::unique_ptr<cBlockEntity>;
using cBlockEntities = std::unordered_map<size_t, OwnedBlockEntity>;





// tolua_begin
class cBlockEntity
{
protected:
	cBlockEntity(BLOCKTYPE a_BlockType, NIBBLETYPE a_BlockMeta, Vector3i a_Pos, cWorld * a_World) :
		m_Pos(a_Pos),
		m_RelX(a_Pos.x - cChunkDef::Width * FAST_FLOOR_DIV(a_Pos.x, cChunkDef::Width)),
		m_RelZ(a_Pos.z - cChunkDef::Width * FAST_FLOOR_DIV(a_Pos.z, cChunkDef::Width)),
		m_BlockType(a_BlockType),
		m_BlockMeta(a_BlockMeta),
		m_World(a_World)
	{
	}

public:
	// tolua_end

	virtual ~cBlockEntity() {}  // force a virtual destructor in all descendants

	virtual void Destroy() {}

	void SetWorld(cWorld * a_World)
	{
		m_World = a_World;
	}

	/** Updates the internally stored position.
	Note that this should not ever be used for world-contained block entities, it is meant only for when BEs in a cBlockArea are manipulated.
	Asserts that the block entity is not assigned to a world. */
	void SetPos(Vector3i a_NewPos);

	/** Returns true if the specified blocktype is supposed to have an associated block entity. */
	static bool IsBlockEntityBlockType(BLOCKTYPE a_BlockType);

	/** Creates a new block entity for the specified block type at the specified absolute pos.
	If a_World is valid, then the entity is created bound to that world
	Returns nullptr for unknown block types. */
	static OwnedBlockEntity CreateByBlockType(BLOCKTYPE a_BlockType, NIBBLETYPE a_BlockMeta, Vector3i a_Pos, cWorld * a_World = nullptr);

	/** Makes an exact copy of this block entity, except for its m_World (set to nullptr), and at a new position.
	Uses CopyFrom() to copy the properties. */
	OwnedBlockEntity Clone(Vector3i a_Pos);

	/** Returns the contents of this block entity that it would drop if broken.
	Note that the block itself is not included; that's handled by the block handler. */
	virtual cItems ConvertToPickups() const;

	/** Copies all properties of a_Src into this entity, except for its m_World and location.
	Each non-abstract descendant should override to copy its specific properties, and call
	Super::CopyFrom(a_Src) to copy the common ones. */
	virtual void CopyFrom(const cBlockEntity & a_Src);

	static const char * GetClassStatic()  // Needed for ManualBindings's ForEach templates
	{
		return "cBlockEntity";
	}

	/** Returns true if the object is the specified class, or its descendant. */
	virtual bool IsA(const char * a_ClassName) const { return (strcmp(a_ClassName, "cBlockEntity") == 0); }

	/** Returns the name of the topmost class (the most descendant). Used for Lua bindings to push the correct object type. */
	virtual const char * GetClass() const { return GetClassStatic(); }

	/** Returns the name of the parent class, or empty string if no parent class. */
	virtual const char * GetParentClass() const { return ""; }

	// tolua_begin

	// Position, in absolute block coordinates:
	Vector3i GetPos() const { return m_Pos; }
	int GetPosX() const { return m_Pos.x; }
	int GetPosY() const { return m_Pos.y; }
	int GetPosZ() const { return m_Pos.z; }

	Vector3i GetRelPos() const { return Vector3i(m_RelX, m_Pos.y, m_RelZ); }

	BLOCKTYPE GetBlockType() const { return m_BlockType; }

	cWorld * GetWorld() const { return m_World; }

	int GetChunkX() const { return FAST_FLOOR_DIV(m_Pos.x, cChunkDef::Width); }
	int GetChunkZ() const { return FAST_FLOOR_DIV(m_Pos.y, cChunkDef::Width); }

	int GetRelX() const { return m_RelX; }
	int GetRelZ() const { return m_RelZ; }

	// tolua_end

	/** Called when a player uses this entity; should open the UI window.
	returns true if the use was successful, return false to use the block as a "normal" block */
	virtual bool UsedBy( cPlayer * a_Player) = 0;

	/** Sends the packet defining the block entity to the client specified.
	To send to all eligible clients, use cWorld::BroadcastBlockEntity() */
	virtual void SendTo(cClientHandle & a_Client) = 0;

	/** Ticks the entity; returns true if the chunk should be marked as dirty as a result of this ticking. By default does nothing. */
	virtual bool Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
	{
		UNUSED(a_Dt);
		return false;
	}


protected:

	/** Position in absolute block coordinates */
	Vector3i m_Pos;

	/** Position relative to the chunk, used to speed up ticking */
	int m_RelX, m_RelZ;

	/** The blocktype representing this particular instance in the world.
	Mainly used for multi-block-type entities, such as furnaces / lit furnaces. */
	BLOCKTYPE m_BlockType;

	/** The block meta representing this particular instance in the world
	Mainly used for directional entities, such as dispensers. */
	NIBBLETYPE m_BlockMeta;

	cWorld * m_World;
} ;  // tolua_export