ZobristHash Class Reference

Zobrist Hashing. More...

#include <ZobristHash.hpp>

List of all members.

Classes
struct	GlobalData
	Data shared amoungst all instances of ZobristHash. More...
Public Member Functions
	ZobristHash (int width, int height)
	Constructs a ZobristHash object for the given boardsize.
hash_t	Hash (HexColor toPlay) const
	Returns the current hash value for the color to play.
hash_t	Hash () const
	Helper function: same as Hash(EMPTY).
void	Reset ()
	Reset hash to the base hash value.
void	Compute (const bitset_t &black, const bitset_t &white)
	Sets the hash to base hash value updated with the played stones in black and white.
void	Update (HexColor color, HexPoint cell)
	Incrementally updates the hash value with the given move.
Static Private Member Functions
static GlobalData &	GetGlobalData ()
	Returns a reference to a static local variable so that it is initialized on first use if some global variable is initialized.
Private Attributes
hash_t	m_hash
	Hash for the current state.
hash_t	m_base
	Base hash.

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Detailed Description

Zobrist Hashing.

Hash values are shared amoung all instances of ZobristHash.

Each unique boardsize has its own base hash, so hashes of positions on different boardsizes should never collide.

Definition at line 22 of file ZobristHash.hpp.

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Constructor & Destructor Documentation

ZobristHash::ZobristHash	(	int	width,
		int	height
	)

Constructs a ZobristHash object for the given boardsize.

Definition at line 67 of file ZobristHash.cpp.

References HexAssert, and Reset().

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Member Function Documentation

void ZobristHash::Compute	(	const bitset_t &	black,
		const bitset_t &	white
	)

Sets the hash to base hash value updated with the played stones in black and white.

Definition at line 80 of file ZobristHash.cpp.

References BITSETSIZE, GetGlobalData(), ZobristHash::GlobalData::m_black_hashes, m_hash, ZobristHash::GlobalData::m_white_hashes, Reset(), and benzene_bitset< _Nb >::test().

Referenced by StoneBoard::ComputeHash().

ZobristHash::GlobalData & ZobristHash::GetGlobalData

(

)

[static, private]

Returns a reference to a static local variable so that it is initialized on first use if some global variable is initialized.

Definition at line 74 of file ZobristHash.cpp.

Referenced by Compute(), Hash(), and Update().

hash_t ZobristHash::Hash

(

)

const [inline]

Helper function: same as Hash(EMPTY).

Definition at line 87 of file ZobristHash.hpp.

References EMPTY.

hash_t ZobristHash::Hash

(

HexColor

toPlay

)

const [inline]

Returns the current hash value for the color to play.

Definition at line 82 of file ZobristHash.hpp.

References GetGlobalData(), m_hash, and ZobristHash::GlobalData::m_toPlay_hashes.

Referenced by StoneBoard::Hash().

void ZobristHash::Reset

(

)

[inline]

Reset hash to the base hash value.

Definition at line 92 of file ZobristHash.hpp.

References m_base, and m_hash.

Referenced by Compute(), and ZobristHash().

void ZobristHash::Update	(	HexColor	color,
		HexPoint	cell
	)			[inline]

Incrementally updates the hash value with the given move.

Definition at line 97 of file ZobristHash.hpp.

References BITSETSIZE, GetGlobalData(), HexAssert, HexColorUtil::isBlackWhite(), ZobristHash::GlobalData::m_color_hashes, and m_hash.

Referenced by StoneBoard::PlayMove(), and StoneBoard::UndoMove().

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Member Data Documentation

hash_t ZobristHash::m_base [private]

Base hash.

Definition at line 50 of file ZobristHash.hpp.

Referenced by Reset().

hash_t ZobristHash::m_hash [private]

Hash for the current state.

Definition at line 47 of file ZobristHash.hpp.

Referenced by Compute(), Hash(), Reset(), and Update().

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The documentation for this class was generated from the following files:

• ZobristHash.hpp
• ZobristHash.cpp