#include "board.h"
#include "bit.h"
#include "hash.h"
#include "move.h"
#include "settings.h"
#include "util.h"
#include <ctype.h>
#include <stdlib.h>
#include <assert.h>
#include "flip_carry_32.c"
#include "count_last_flip_carry_32.c"

Macros
#define	packA1A8(X) (((((unsigned int)(X) & 0x01010101u) + (((unsigned int)((X) >> 32) & 0x01010101u) << 4)) * 0x01020408u) >> 24)

#define	packH1H8(X) (((((unsigned int)((X) >> 32) & 0x80808080u) + (((unsigned int)(X) & 0x80808080u) >> 4)) * 0x00204081u) >> 24)

Functions
void	board_swap_players (Board *board)
	Swap players. More...

int	board_set (Board board, const char string)
	Set a board from a string description. More...

int	board_from_FEN (Board board, const char string)
	Set a board from a string description. More...

int	board_from_obj (Board board, const Board obj, const int turn)
	Set a board from a Board object. More...

void	board_init (Board *board)
	Set a board to the starting position. More...

void	board_check (const Board *board)
	Check board consistency. More...

int	board_compare (const Board b1, const Board b2)
	Compare two board. More...

bool	board_equal (const Board b1, const Board b2)
	Compare two board for equality. More...

void	board_symetry (const Board board, const int s, Board sym)
	symetric board More...

int	board_unique (const Board board, Board unique)
	unique board More...

void	board_rand (Board board, int n_ply, Random r)
	Get a random board by playing random moves. More...

unsigned long long	board_get_move (const Board board, const int x, Move move)
	Compute a move. More...

bool	board_check_move (const Board board, Move move)
	Check if a move is legal. More...

void	board_update (Board board, const Move move)
	Update a board. More...

void	board_restore (Board board, const Move move)
	Restore a board. More...

void	board_pass (Board *board)
	Passing move. More...

unsigned long long	board_next (const Board board, const int x, Board next)
	Compute a board resulting of a move played on a previous board. More...

unsigned long long	board_pass_next (const Board board, const int x, Board next)
	Compute a board resulting of an opponent move played on a previous board. More...

static unsigned long long	get_some_moves (const unsigned long long P, const unsigned long long mask, const int dir)
	Get a part of the moves. More...

DLL_API unsigned long long	get_moves (const unsigned long long P, const unsigned long long O)
	Get legal moves. More...

unsigned long long	get_moves_6x6 (const unsigned long long P, const unsigned long long O)
	Get legal moves on a 6x6 board. More...

DLL_API bool	can_move (const unsigned long long P, const unsigned long long O)
	Check if a player can move. More...

bool	can_move_6x6 (const unsigned long long P, const unsigned long long O)
	Check if a player can move. More...

int	get_mobility (const unsigned long long P, const unsigned long long O)
	Count legal moves. More...

int	get_weighted_mobility (const unsigned long long P, const unsigned long long O)

static unsigned long long	get_some_potential_moves (const unsigned long long P, const int dir)
	Get some potential moves. More...

static unsigned long long	get_potential_moves (const unsigned long long P, const unsigned long long O)
	Get potential moves. More...

int	get_potential_mobility (const unsigned long long P, const unsigned long long O)
	Get potential mobility. More...

static int	find_edge_stable (const int old_P, const int old_O, int stable)
	search stable edge patterns. More...

void	edge_stability_init (void)
	Initialize the edge stability tables. More...

static unsigned long long	get_full_lines (const unsigned long long line, const int dir)
	Get full lines. More...

static unsigned long long	get_stable_edge (const unsigned long long P, const unsigned long long O)
	Get stable edge. More...

int	get_stability (const unsigned long long P, const unsigned long long O)
	Estimate the stability. More...

int	get_edge_stability (const unsigned long long P, const unsigned long long O)
	Estimate the stability of edges. More...

int	get_corner_stability (const unsigned long long P)
	Estimate corner stability. More...

unsigned long long	board_get_hash_code (const Board *board)
	Compute a hash code. More...

int	board_get_square_color (const Board *board, const int x)
	Get square color. More...

bool	board_is_occupied (const Board *board, const int x)
	Check if a square is occupied. More...

bool	board_is_pass (const Board *board)
	Check if current player should pass. More...

bool	board_is_game_over (const Board *board)
	Check if the game is over. More...

int	board_count_empties (const Board *board)
	Check if the game is over. More...

void	board_print (const Board board, const int player, FILE f)
	Print out the board. More...

char *	board_to_string (const Board board, const int player, char s)
	convert the to a compact string. More...

void	board_print_FEN (const Board board, const int player, FILE f)
	print using FEN description. More...

char *	board_to_FEN (const Board board, const int player, char string)
	print to FEN description. More...

Variables
static unsigned char	edge_stability [256][256]

static const unsigned long long	A1_A8 [256]

static const unsigned long long	H1_H8 [256]

Detailed Description

This module deals with the Board management.

The Board is represented with a structure containing the following data:

a bitboard with the current player's square.
a bitboard with the current opponent's square.

High level functions are provided to set/modify the board data or to compute some board properties. Most of the functions are optimized to be as fast as possible, while remaining readable.

Date: 1998 - 2017

Author: Richard Delorme

Version: 4.4

Macro Definition Documentation

◆ packA1A8

#define packA1A8 ( X ) (((((unsigned int)(X) & 0x01010101u) + (((unsigned int)((X) >> 32) & 0x01010101u) << 4)) * 0x01020408u) >> 24)

◆ packH1H8

#define packH1H8 ( X ) (((((unsigned int)((X) >> 32) & 0x80808080u) + (((unsigned int)(X) & 0x80808080u) >> 4)) * 0x00204081u) >> 24)

Function Documentation

◆ board_check()

void board_check ( const Board * board )

Check board consistency.

Parameters

board the board to initialize

◆ board_check_move()

bool board_check_move	(	const Board *	board,
		Move *	move
	)

Check if a move is legal.

Parameters

board	board
move	a Move.

Returns: true if the move is legal, false otherwise.

◆ board_compare()

int board_compare	(	const Board *	b1,
		const Board *	b2
	)

Compare two board.

Parameters

b1	first board
b2	second board

Returns: -1, 0, 1

◆ board_count_empties()

int board_count_empties ( const Board * board )

Check if the game is over.

Parameters

board board.

Returns: true if game is over, false otherwise.

◆ board_equal()

bool board_equal	(	const Board *	b1,
		const Board *	b2
	)

Compare two board for equality.

Parameters

b1	first board
b2	second board

Returns: true if both board are equal

◆ board_from_FEN()

int board_from_FEN	(	Board *	board,
		const char *	string
	)

Set a board from a string description.

Read a Forsyth-Edwards Notation string and translate it into our internal Board structure.

Parameters

board	the board to set
string	string describing the board

Returns: turn's color.

◆ board_from_obj()

int board_from_obj	(	Board *	board,
		const Board *	obj,
		const int	turn
	)

Set a board from a Board object.

Parameters

board	the board to set
obj	object describing the board. assumes player attribute as black, opponent attribute as white
turn	turn's color

Returns: turn's color.

Date: 2018

Author: lavox

◆ board_get_hash_code()

unsigned long long board_get_hash_code ( const Board * board )

Compute a hash code.

Parameters

board the board.

Returns: the hash code of the bitboard

◆ board_get_move()

unsigned long long board_get_move	(	const Board *	board,
		const int	x,
		Move *	move
	)

Compute a move.

Compute how the board will be modified by a move without playing it.

Parameters

board	board
x	square on which to move.
move	a Move structure remembering the modification.

Returns: the flipped discs.

◆ board_get_square_color()

int board_get_square_color	(	const Board *	board,
		const int	x
	)

Get square color.

returned value: 0 = player, 1 = opponent, 2 = empty;

Parameters

board	board.
x	square coordinate.

Returns: square color.

◆ board_init()

void board_init ( Board * board )

Set a board to the starting position.

Parameters

board the board to initialize

◆ board_is_game_over()

bool board_is_game_over ( const Board * board )

Check if the game is over.

Parameters

board board.

Returns: true if game is over, false otherwise.

◆ board_is_occupied()

bool board_is_occupied	(	const Board *	board,
		const int	x
	)

Check if a square is occupied.

Parameters

board	board.
x	square coordinate.

Returns: true if a square is occupied.

◆ board_is_pass()

bool board_is_pass ( const Board * board )

Check if current player should pass.

Parameters

board board.

Returns: true if player is passing, false otherwise.

◆ board_next()

unsigned long long board_next	(	const Board *	board,
		const int	x,
		Board *	next
	)

Compute a board resulting of a move played on a previous board.

Parameters

board	board to play the move on.
x	move to play.
next	resulting board.

Returns: flipped discs.

◆ board_pass()

void board_pass ( Board * board )

Passing move.

Modify a board by passing player's turn.

Parameters

board board to update.

◆ board_pass_next()

unsigned long long board_pass_next	(	const Board *	board,
		const int	x,
		Board *	next
	)

Compute a board resulting of an opponent move played on a previous board.

Compute the board after passing and playing a move.

Parameters

board	board to play the move on.
x	opponent move to play.
next	resulting board.

Returns: flipped discs.

◆ board_print()

void board_print	(	const Board *	board,
		const int	player,
		FILE *	f
	)

Print out the board.

Print an ASCII representation of the board to an output stream.

Parameters

board	board to print.
player	player's color.
f	output stream.

◆ board_print_FEN()

void board_print_FEN	(	const Board *	board,
		const int	player,
		FILE *	f
	)

print using FEN description.

Write the board according to the Forsyth-Edwards Notation.

Parameters

board	the board to write
player	turn's color.
f	output stream.

◆ board_rand()

void board_rand	(	Board *	board,
		int	n_ply,
		Random *	r
	)

Get a random board by playing random moves.

Parameters

board	The output board.
n_ply	The number of random move to generate.
r	The random generator.

◆ board_restore()

void board_restore	(	Board *	board,
		const Move *	move
	)

Restore a board.

Restore a board by un-flipping its discs and restoring every other data, according to the 'move' description, in order to cancel a board_update_move.

Parameters

board	board to restore.
move	a Move structure describing the modification.

◆ board_set()

int board_set	(	Board *	board,
		const char *	string
	)

Set a board from a string description.

Read a standardized string (See http://www.nada.kth.se/~gunnar/download2.html for details) and translate it into our internal Board structure.

Parameters

board	the board to set
string	string describing the board

Returns: turn's color.

◆ board_swap_players()

void board_swap_players ( Board * board )

Swap players.

Swap players, i.e. change player's turn.

Parameters

board board

◆ board_symetry()

void board_symetry	(	const Board *	board,
		const int	s,
		Board *	sym
	)

symetric board

Parameters

board	input board
s	symetry
sym	symetric output board

◆ board_to_FEN()

char * board_to_FEN	(	const Board *	board,
		const int	player,
		char *	string
	)

print to FEN description.

Write the board into a Forsyth-Edwards Notation string.

Parameters

board	the board to write
player	turn's color.
string	output string.

◆ board_to_string()

char * board_to_string	(	const Board *	board,
		const int	player,
		char *	s
	)

convert the to a compact string.

Parameters

board	board to convert.
player	player's color.
s	output string.

◆ board_unique()

int board_unique	(	const Board *	board,
		Board *	unique
	)

unique board

Compute a board unique from all its possible symertries.

Parameters

board	input board
unique	output board

◆ board_update()

void board_update	(	Board *	board,
		const Move *	move
	)

Update a board.

Update a board by flipping its discs and updating every other data, according to the 'move' description.

Parameters

board	the board to modify
move	A Move structure describing the modification.

◆ can_move()

DLL_API bool can_move	(	const unsigned long long	P,
		const unsigned long long	O
	)

Check if a player can move.

Parameters

P	bitboard with player's discs.
O	bitboard with opponent's discs.

Returns: true or false.

◆ can_move_6x6()

bool can_move_6x6	(	const unsigned long long	P,
		const unsigned long long	O
	)

Check if a player can move.

Parameters

P	bitboard with player's discs.
O	bitboard with opponent's discs.

Returns: true or false.

◆ edge_stability_init()

void edge_stability_init ( void )

Initialize the edge stability tables.

◆ find_edge_stable()

static int find_edge_stable	(	const int	old_P,
		const int	old_O,
		int	stable
	)

static

search stable edge patterns.

Compute a 8-bit bitboard where each stable square is set to one

Parameters

old_P	previous player edge discs.
old_O	previous opponent edge discs.
stable	8-bit bitboard with stable edge squares.

◆ get_corner_stability()

int get_corner_stability ( const unsigned long long P )

Estimate corner stability.

Count the number of stable discs around the corner. Limiting the count to the corner keep the function fast but still get this information, particularly important at Othello. Corner stability will be used for move sorting.

Parameters

P	bitboard with player's discs.

Returns: the number of stable discs around the corner.

◆ get_edge_stability()

int get_edge_stability	(	const unsigned long long	P,
		const unsigned long long	O
	)

Estimate the stability of edges.

Count the number (in fact a lower estimate) of stable discs on the edges.

Parameters

P	bitboard with player's discs.
O	bitboard with opponent's discs.

Returns: the number of stable discs on the edges.

◆ get_full_lines()

static unsigned long long get_full_lines	(	const unsigned long long	line,
		const int	dir
	)

inlinestatic

Get full lines.

Parameters

line	all discs on a line.
dir	tested direction

Returns: a bitboard with full lines along the tested direction.

◆ get_mobility()

int get_mobility	(	const unsigned long long	P,
		const unsigned long long	O
	)

Count legal moves.

Compute mobility, ie the number of legal moves.

Parameters

P	bitboard with player's discs.
O	bitboard with opponent's discs.

Returns: a count of all legal moves.

◆ get_moves()

DLL_API unsigned long long get_moves	(	const unsigned long long	P,
		const unsigned long long	O
	)

Get legal moves.

Compute a bitboard where each coordinate with a legal move is set to one.

Parameters

P	bitboard with player's discs.
O	bitboard with opponent's discs.

Returns: all legal moves in a 64-bit unsigned integer.

◆ get_moves_6x6()

unsigned long long get_moves_6x6	(	const unsigned long long	P,
		const unsigned long long	O
	)

Get legal moves on a 6x6 board.

Compute a bitboard where each coordinate with a legal move is set to one.

Parameters

P	bitboard with player's discs.
O	bitboard with opponent's discs.

Returns: all legal moves in a 64-bit unsigned integer.

◆ get_potential_mobility()

int get_potential_mobility	(	const unsigned long long	P,
		const unsigned long long	O
	)

Get potential mobility.

Count the list of empty squares in contact of a player square.

Parameters

P	bitboard with player's discs.
O	bitboard with opponent's discs.

Returns: a count of potential moves.

◆ get_potential_moves()

static unsigned long long get_potential_moves	(	const unsigned long long	P,
		const unsigned long long	O
	)

static

Get potential moves.

Get the list of empty squares in contact of a player square.

Parameters

P	bitboard with player's discs.
O	bitboard with opponent's discs.

Returns: all potential moves in a 64-bit unsigned integer.

◆ get_some_moves()

static unsigned long long get_some_moves	(	const unsigned long long	P,
		const unsigned long long	mask,
		const int	dir
	)

inlinestatic

Get a part of the moves.

Partially compute a bitboard where each coordinate with a legal move is set to one.

Two variants of the algorithm are provided, one based on Kogge-Stone parallel prefix.

Parameters

P	bitboard with player's discs.
mask	bitboard with flippable opponent's discs.
dir	flipping direction.

Returns: some legal moves in a 64-bit unsigned integer.

◆ get_some_potential_moves()

static unsigned long long get_some_potential_moves	(	const unsigned long long	P,
		const int	dir
	)

inlinestatic

Get some potential moves.

Parameters

P	bitboard with player's discs.
dir	flipping direction.

Returns: some potential moves in a 64-bit unsigned integer.

◆ get_stability()

int get_stability	(	const unsigned long long	P,
		const unsigned long long	O
	)

Estimate the stability.

Count the number (in fact a lower estimate) of stable discs.

Parameters

P	bitboard with player's discs.
O	bitboard with opponent's discs.

Returns: the number of stable discs.

◆ get_stable_edge()

static unsigned long long get_stable_edge	(	const unsigned long long	P,
		const unsigned long long	O
	)

inlinestatic

Get stable edge.

Parameters

P	bitboard with player's discs.
O	bitboard with opponent's discs.

Returns: a bitboard with (some of) player's stable discs.

◆ get_weighted_mobility()

int get_weighted_mobility	(	const unsigned long long	P,
		const unsigned long long	O
	)

Variable Documentation

◆ A1_A8

const unsigned long long A1_A8[256]

static

conversion from an 8-bit line to the A1-A8 line

◆ edge_stability

unsigned char edge_stability[256][256]

static

edge stability global data

◆ H1_H8

const unsigned long long H1_H8[256]

static

conversion from an 8-bit line to the H1-H8 line

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ packA1A8

◆ packH1H8

Function Documentation

◆ board_check()

◆ board_check_move()

◆ board_compare()

◆ board_count_empties()

◆ board_equal()

◆ board_from_FEN()

◆ board_from_obj()

◆ board_get_hash_code()

◆ board_get_move()

◆ board_get_square_color()

◆ board_init()

◆ board_is_game_over()

◆ board_is_occupied()

◆ board_is_pass()

◆ board_next()

◆ board_pass()

◆ board_pass_next()

◆ board_print()

◆ board_print_FEN()

◆ board_rand()

◆ board_restore()

◆ board_set()

◆ board_swap_players()

◆ board_symetry()

◆ board_to_FEN()

◆ board_to_string()

◆ board_unique()

◆ board_update()

◆ can_move()

◆ can_move_6x6()

◆ edge_stability_init()

◆ find_edge_stable()

◆ get_corner_stability()

◆ get_edge_stability()

◆ get_full_lines()

◆ get_mobility()

◆ get_moves()

◆ get_moves_6x6()

◆ get_potential_mobility()

◆ get_potential_moves()

◆ get_some_moves()

◆ get_some_potential_moves()

◆ get_stability()

◆ get_stable_edge()

◆ get_weighted_mobility()

Variable Documentation

◆ A1_A8

◆ edge_stability

◆ H1_H8