cuberite-2a/src/Generating/Prefab.h

// Prefab.h

/*
Declares the cPrefab class, representing a cPiece descendant for the cPieceGenerator that
uses a prefabricate in a cBlockArea for drawing itself.
The class can be constructed from data that is stored directly in the executable, in a sPrefabDef structure
declared in this file as well; the Gallery server exports areas in this format.
*/





#pragma once

#include "PiecePool.h"
#include "../BlockArea.h"





// fwd:
class cChunkDesc;





class cPrefab :
	public cPiece
{
public:
	/** How to handle the space between the prefab bottom and the terrain top. */
	enum eExtendFloorStrategy
	{
		efsNone,                    ///< No processing, the prefab is left "floating in the air"
		efsRepeatBottomTillNonAir,  ///< Repeat the bottom-most block down until the first non-air block
		efsRepeatBottomTillSolid,   ///< Repeat the bottom-most block down until the first solid block; non-solids are overwritten
	};

	struct sDef
	{
		int m_SizeX;
		int m_SizeY;
		int m_SizeZ;

		/** The hitbox used for collision-checking between prefabs. Relative to the bounds. */
		int m_HitboxMinX, m_HitboxMinY, m_HitboxMinZ;
		int m_HitboxMaxX, m_HitboxMaxY, m_HitboxMaxZ;

		/** The mapping between characters in m_Image and the blocktype / blockmeta.
		Format: "Char: BlockType: BlockMeta \n Char: BlockType : BlockMeta \n ..." */
		const char * m_CharMap;

		/** The actual image to be used for the prefab. Organized YZX (Y changes the least often).
		Each character represents a single block, the type is mapped through m_CharMap. */
		const char * m_Image;

		/** List of connectors.
		Format: "Type: X, Y, Z : Direction \n Type : X, Y, Z : Direction \n ...".
		Type is an arbitrary number, Direction is the BlockFace constant value (0 .. 5). */
		const char * m_Connectors;

		/** Bitmask specifying the allowed rotations.
		N rotations CCW are allowed if bit N is set. */
		int m_AllowedRotations;

		/** The merge strategy to use while drawing the prefab. */
		cBlockArea::eMergeStrategy m_MergeStrategy;

		/** How the prefab should handle not being on top of the ground.
		This is used for houses to be "on the ground", as well as nether fortresses not to float. */
		eExtendFloorStrategy m_ExtendFloorStrategy;

		/** Chance of this piece being used, if no other modifier is active. */
		int m_DefaultWeight;

		/** Chances of this piece being used, per depth of the generated piece tree.
		The starting piece has a depth of 0, the pieces connected to it are depth 1, etc.
		The specified depth stands for the depth of the new piece (not the existing already-placed piece),
		so valid depths start at 1.
		Format: "Depth : Weight | Depth : Weight | Depth : Weight ..."
		Depths that are not specified will use the m_DefaultWeight value. */
		const char * m_DepthWeight;

		/** The weight to add to this piece's base per-depth chance if the previous piece is the same.
		Can be positive or negative.
		This is used e. g. to make nether bridges prefer spanning multiple segments or to penalize turrets next to each other. */
		int m_AddWeightIfSame;

		/** If true, the piece will be moved Y-wise so that its first connector is sitting on the terrain.
		This is used e. g. for village houses. */
		bool m_MoveToGround;
	};


	/** Creates a prefab from the provided definition. */
	cPrefab(const sDef & a_Def);

	/** Creates a prefab based on the given BlockArea and allowed rotations. */
	cPrefab(const cBlockArea & a_Image, int a_AllowedRotations);

	/** Creates a prefab based on the given BlockArea. Allowed rotations can be added later on using SetAllowedRotations(). */
	cPrefab(const cBlockArea & a_Image);

	/** Creates a prefab based on the specified block data, using the char-to-block map in a_BlockDefinitions.
	Allowed rotations can be added later on using SetAllowedRotations(). */
	cPrefab(const AString & a_BlockDefinitions, const AString & a_BlockData, int a_SizeX, int a_SizeY, int a_SizeZ);

	/** Draws the prefab into the specified chunk, according to the placement stored in the PlacedPiece. */
	void Draw(cChunkDesc & a_Dest, const cPlacedPiece * a_Placement) const;

	/** Draws the prefab into the specified chunks, according to the specified placement and rotations. */
	void Draw(cChunkDesc & a_Dest, const Vector3i & a_Placement, int a_NumRotations) const;

	/** Returns true if the prefab has any connector of the specified type. */
	bool HasConnectorType(int a_ConnectorType) const;

	/** Returns the weight (chance) of this prefab generating as the next piece after the specified placed piece.
	PiecePool implementations can use this for their GetPieceWeight() implementations. */
	int GetPieceWeight(const cPlacedPiece & a_PlacedPiece, const cPiece::cConnector & a_ExistingConnector) const;

	/** Sets the (unmodified) DefaultWeight property for this piece. */
	void SetDefaultWeight(int a_DefaultWeight);

	/** Returns the unmodified DefaultWeight property for the piece. */
	int GetDefaultWeight(void) const { return m_DefaultWeight; }

	/** Sets the AddWeightIfSame member, that is used to modify the weight when the previous piece is the same prefab */
	void SetAddWeightIfSame(int a_AddWeightIfSame) { m_AddWeightIfSame = a_AddWeightIfSame; }

	/** Adds the specified connector to the list of connectors this piece supports. */
	void AddConnector(int a_RelX, int a_RelY, int a_RelZ, cPiece::cConnector::eDirection a_Direction, int a_Type);

	/** Returns whether the prefab should be moved Y-wise to ground before drawing, rather than staying
	at the coords governed by the connectors. */
	bool ShouldMoveToGround(void) const { return m_MoveToGround; }

	/** Sets the m_AllowedRotations bitmask and fills the m_BlockArea[] with rotated versions of m_BlockArea[0]. */
	void SetAllowedRotations(int a_AllowedRotations);

	/** Parses the per-depth weight into m_DepthWeight member. */
	void ParseDepthWeight(const char * a_DepthWeightDef);

	/** Sets the merge strategy to be used when drawing the piece. */
	void SetMergeStrategy(cBlockArea::eMergeStrategy a_MergeStrategy) { m_MergeStrategy = a_MergeStrategy; }

	/** Sets the flag whether the prefab should be moved to ground level before being drawn. */
	void SetMoveToGround(bool a_MoveToGround) { m_MoveToGround = a_MoveToGround; }

	/** Sets the strategy to use between the bottom of the prefab and the terrain top. */
	void SetExtendFloorStrategy(eExtendFloorStrategy a_Strategy) { m_ExtendFloorStrategy = a_Strategy; }

	/** Sets the internal hitbox to the specified value. */
	void SetHitBox(const cCuboid & a_HitBox) { m_HitBox = a_HitBox; }

protected:
	/** Packs complete definition of a single block, for per-letter assignment. */
	struct sBlockTypeDef
	{
		BLOCKTYPE  m_BlockType;
		NIBBLETYPE m_BlockMeta;
	};

	/** Maps letters in the sDef::m_Image onto a sBlockTypeDef block type definition. */
	typedef sBlockTypeDef CharMap[256];

	/** Maps generator tree depth to weight. */
	typedef std::map<int, int> cDepthWeight;


	/** The cBlockArea that contains the block definitions for the prefab.
	The index identifies the number of CCW rotations applied (0 = no rotation, 1 = 1 CCW rotation, ...). */
	cBlockArea m_BlockArea[4];

	/** The size of the prefab */
	Vector3i m_Size;

	/** The hitbox used for collision-checking between prefabs. */
	cCuboid m_HitBox;

	/** The connectors through which the piece connects to other pieces */
	cConnectors m_Connectors;

	/** Bitmask, bit N set -> N rotations CCW supported */
	int m_AllowedRotations;

	/** The merge strategy to use when drawing the prefab into a block area */
	cBlockArea::eMergeStrategy m_MergeStrategy;

	/** How the prefab should handle not being on top of the ground.
	This is used for houses to be "on the ground", as well as nether fortresses not to float. */
	eExtendFloorStrategy m_ExtendFloorStrategy;

	/** Chance of this piece being used, if no other modifier is active. */
	int m_DefaultWeight;

	/** Chances of this piece being used, per depth of the generated piece tree.
	The starting piece has a depth of 0, the pieces connected to it are depth 1, etc.
	The specified depth stands for the depth of the new piece (not the existing already-placed piece),
	so valid depths start at 1.
	Depths that are not specified will use the m_DefaultWeight value. */
	cDepthWeight m_DepthWeight;

	/** The weight to add to this piece's base per-depth chance if the previous piece is the same.
	Can be positive or negative.
	This is used e. g. to make nether bridges prefer spanning multiple segments or to penalize turrets next to each other. */
	int m_AddWeightIfSame;

	/** If true, the piece will be moved Y-wise so that its first connector is sitting on the terrain.
	This is used e. g. for village houses. */
	bool m_MoveToGround;


	// cPiece overrides:
	virtual cConnectors GetConnectors(void) const override;
	virtual Vector3i GetSize(void) const override;
	virtual cCuboid GetHitBox(void) const override;
	virtual bool CanRotateCCW(int a_NumRotations) const override;

	/** Based on the m_AllowedRotations, adds rotated cBlockAreas to the m_BlockArea array.
	To be called only from this class's constructor! */
	void AddRotatedBlockAreas(void);

	/** Parses the CharMap in the definition into a CharMap binary data used for translating the definition into BlockArea. */
	void ParseCharMap(CharMap & a_CharMapOut, const char * a_CharMapDef);

	/** Parses the Image in the definition into m_BlockArea[0]'s block types and metas, using the specified CharMap. */
	void ParseBlockImage(const CharMap & a_CharMap, const char * a_BlockImage);

	/** Parses the connectors definition text into m_Connectors member. */
	void ParseConnectors(const char * a_ConnectorsDef);
};