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/* util.c
GNU Chess frontend
Copyright (C) 2001-2011 Free Software Foundation, Inc.
GNU Chess is based on the two research programs
Cobalt by Chua Kong-Sian and Gazebo by Stuart Cracraft.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
Contact Info:
bug-gnu-chess@gnu.org
cracraft@ai.mit.edu, cracraft@stanfordalumni.org, cracraft@earthlink.net
*/
#include <stdio.h>
#include <string.h>
#include "common.h"
/*
* We actually do not have this configuration variable yet,
* should be manually added when inlining is not possible.
* If inlining is possible, these functions have now moved
* to util.h which must be included by all callers of
* leadz() and nbits().
*/
#ifdef NO_INLINE
unsigned char leadz (BitBoard b)
/**************************************************************************
*
* Returns the leading bit in a bitboard. Leftmost bit is 0 and
* rightmost bit is 63. Thanks to Robert Hyatt for this algorithm.
*
***************************************************************************/
{
if (b >> 48) return lzArray[b >> 48];
if (b >> 32) return lzArray[b >> 32] + 16;
if (b >> 16) return lzArray[b >> 16] + 32;
return lzArray[b] + 48;
}
unsigned char nbits (BitBoard b)
/***************************************************************************
*
* Count the number of bits in b.
*
***************************************************************************/
{
return BitCount[b>>48] + BitCount[(b>>32) & 0xffff]
+ BitCount[(b>>16) & 0xffff] + BitCount[b & 0xffff];
}
#endif /* NO_INLINE */
void UpdateFriends (void)
/***************************************************************************
*
* Update friend and enemy bitboard.
*
***************************************************************************/
{
register BitBoard *w, *b;
w = board.b[white];
b = board.b[black];
board.friends[white] =
w[pawn] | w[knight] | w[bishop] | w[rook] | w[queen] | w[king];
board.friends[black] =
b[pawn] | b[knight] | b[bishop] | b[rook] | b[queen] | b[king];
board.blocker = board.friends[white] | board.friends[black];
}
void UpdateCBoard (void)
/**************************************************************************
*
* Updates cboard[]. cboard[i] returns the piece on square i.
*
**************************************************************************/
{
BitBoard b;
int piece, sq;
memset (cboard, 0, sizeof (cboard));
for (piece = pawn; piece <= king; piece++)
{
b = board.b[white][piece] | board.b[black][piece];
while (b)
{
sq = leadz (b);
CLEARBIT (b, sq);
cboard[sq] = piece;
}
}
}
static const int OrigCboard[64] =
{ rook, knight, bishop, queen, king, bishop, knight, rook,
pawn, pawn, pawn, pawn, pawn, pawn, pawn, pawn,
empty, empty, empty, empty, empty, empty, empty, empty,
empty, empty, empty, empty, empty, empty, empty, empty,
empty, empty, empty, empty, empty, empty, empty, empty,
empty, empty, empty, empty, empty, empty, empty, empty,
pawn, pawn, pawn, pawn, pawn, pawn, pawn, pawn,
rook, knight, bishop, queen, king, bishop, knight, rook };
void UpdateMvboard (void)
/**************************************************************************
*
* Updates Mvboard[]. Mvboard[i] returns the number of times the piece
* on square i have moved. When loading from EPD, if a piece is not on
* its original square, set it to 1, otherwise set to 0.
*
**************************************************************************/
{
int sq;
for (sq = 0; sq < 64; sq++)
{
if (cboard[sq] == empty || cboard[sq] == OrigCboard[sq])
Mvboard[sq] = 0;
else
Mvboard[sq] = 1;
}
}
short ValidateBoard (void)
/***************************************************************************
*
* Check the board to make sure that its valid. Some things to check are
* a. Both sides have only 1 king.
* b. Side not on the move must not be in check.
* c. If en passant square is set, check it is possible.
* d. Check if castling status are all correct.
*
***************************************************************************/
{
int side, xside, sq;
if (nbits (board.b[white][king]) != 1)
return (false);
if (nbits (board.b[black][king]) != 1)
return (false);
side = board.side;
xside = 1^side;
if (SqAtakd (board.king[xside], side))
return (false);
if (board.ep > -1)
{
sq = board.ep + (xside == white ? 8 : -8);
if (!(BitPosArray[sq] & board.b[xside][pawn]))
return (false);
}
if (board.flag & WKINGCASTLE)
{
if (!(BitPosArray[E1] & board.b[white][king]))
return (false);
if (!(BitPosArray[H1] & board.b[white][rook]))
return (false);
}
if (board.flag & WQUEENCASTLE)
{
if (!(BitPosArray[E1] & board.b[white][king]))
return (false);
if (!(BitPosArray[A1] & board.b[white][rook]))
return (false);
}
if (board.flag & BKINGCASTLE)
{
if (!(BitPosArray[E8] & board.b[black][king]))
return (false);
if (!(BitPosArray[H8] & board.b[black][rook]))
return (false);
}
if (board.flag & BQUEENCASTLE)
{
if (!(BitPosArray[E8] & board.b[black][king]))
return (false);
if (!(BitPosArray[A8] & board.b[black][rook]))
return (false);
}
return (true);
}
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