com.alonsoruibal.chess.bitboard

Class BitboardAttacks

java.lang.Object

com.alonsoruibal.chess.bitboard.BitboardAttacks

public class BitboardAttacks
extends Object

Discover attacks to squares

Field Summary

Fields

Modifier and Type	Field and Description
static long[][]	bishopMagic
static byte[]	bishopShiftBits
static boolean	initialized
static long[]	king
static long[]	knight
static long[]	pawnDownwards
static long[]	pawnUpwards
static byte[]	rookShiftBits

Constructor Summary

Constructors

Constructor and Description
BitboardAttacks()

Method Summary

Modifier and Type	Method and Description
static void	generateAttacks()
static long	generatePieces(int index, int bits, long mask) Fills pieces from a mask.
static long	getBishopAttacks(int index, long all)
static long	getBishopShiftAttacks(long square, long all)
static long	getIndexAttacks(com.alonsoruibal.chess.Board board, int index) Discover attacks to squares using magics: cheap version
static long	getRookAttacks(int index, long all) Magic! attacks, very fast method
static long	getRookShiftAttacks(long square, long all) without magic bitboards, too expensive, but neccesary for magic generation
static long	getXrayAttacks(com.alonsoruibal.chess.Board board, int index, long all)
static void	init() Build/load attack tables
static boolean	isIndexAttacked(com.alonsoruibal.chess.Board board, byte index, boolean white) Discover attacks to squares using magics: cheap version
static boolean	isSquareAttacked(com.alonsoruibal.chess.Board board, long square, boolean white) Discover attacks to squares using magics: expensive version
static int	magicTransform(long b, long magic, byte bits)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

initialized

public static boolean initialized

rookShiftBits

public static final byte[] rookShiftBits

bishopShiftBits

public static final byte[] bishopShiftBits

bishopMagic

public static long[][] bishopMagic

knight

public static long[] knight

king

public static long[] king

pawnDownwards

public static long[] pawnDownwards

pawnUpwards

public static long[] pawnUpwards

Constructor Detail

BitboardAttacks

public BitboardAttacks()

Method Detail

generateAttacks

public static void generateAttacks()

init

public static void init()

Build/load attack tables

isSquareAttacked

public static boolean isSquareAttacked(com.alonsoruibal.chess.Board board,
                                       long square,
                                       boolean white)

Discover attacks to squares using magics: expensive version

isIndexAttacked

public static boolean isIndexAttacked(com.alonsoruibal.chess.Board board,
                                      byte index,
                                      boolean white)

Discover attacks to squares using magics: cheap version

getIndexAttacks

public static long getIndexAttacks(com.alonsoruibal.chess.Board board,
                                   int index)

Discover attacks to squares using magics: cheap version

getXrayAttacks

public static long getXrayAttacks(com.alonsoruibal.chess.Board board,
                                  int index,
                                  long all)

getRookAttacks

public static long getRookAttacks(int index,
                                  long all)

Magic! attacks, very fast method

getBishopAttacks

public static long getBishopAttacks(int index,
                                    long all)

magicTransform

public static int magicTransform(long b,
                                 long magic,
                                 byte bits)

generatePieces

public static long generatePieces(int index,
                                  int bits,
                                  long mask)

Fills pieces from a mask. Neccesary for magic generation variable bits is the mask bytes number index goes from 0 to 2^bits

getRookShiftAttacks

public static long getRookShiftAttacks(long square,
                                       long all)

without magic bitboards, too expensive, but neccesary for magic generation

getBishopShiftAttacks

public static long getBishopShiftAttacks(long square,
                                         long all)