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experiment: add pos_set_checkers_pinners_blockers()

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Bruno Raoult
2024-03-30 18:45:13 +01:00
parent 96744cea20
commit 4816b4a53a
6 changed files with 151 additions and 15 deletions
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89
src/position.c
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@@ -24,6 +24,7 @@
#include "chessdefs.h"
#include "position.h"
#include "bitboard.h"
#include "hyperbola-quintessence.h"
#include "fen.h"
#include "piece.h"
#include "util.h"
@@ -194,17 +195,83 @@ bitboard_t pos_checkers(const pos_t *pos, const color_t color)
* It should be faster than @pos_checkers + @pos_set_pinners_blockers, as
* some calculation will be done once.
*/
/*
* void pos_set_checkers_pinners_blockers(pos_t *pos)
* {
* bitboard_t b_bb = pos->bb[WHITE][BISHOP] | pos->bb[BLACK][BISHOP];
* bitboard_t r_bb = pos->bb[WHITE][ROOK] | pos->bb[BLACK][ROOK];
* bitboard_t q_bb = pos->bb[WHITE][QUEEN] | pos->bb[BLACK][QUEEN];
*
* /\* find out first piece on every diagonal *\/
*
* }
*/
void pos_set_checkers_pinners_blockers(pos_t *pos)
{
int us = pos->turn, them = OPPONENT(us);
bitboard_t occ = pos_occ(pos);
bitboard_t attackers;
bitboard_t checkers = 0, blockers = 0, pinners = 0;
bitboard_t targets, tmpcheckers, tmpblockers, tmppinners, tmpbb;
square_t king = pos->king[us];
bitboard_t king_bb = mask(king);
int pinner;
/* bishop type - we attack with a bishop from king position */
attackers = pos->bb[them][BISHOP] | pos->bb[them][QUEEN];
/* targets is all "target" pieces if K was a bishop */
targets = hyperbola_bishop_moves(occ, king) & occ;
/* checkers = only opponent B/Q */
tmpcheckers = targets & attackers;
checkers |= tmpcheckers;
/* maybe blockers = not checkers */
tmpblockers = targets & ~tmpcheckers;
/* we find second targets, by removing only first ones (excl. checkers) */
targets = hyperbola_bishop_moves(occ ^ tmpblockers, king) ^ tmpcheckers;
/* pinners = only B/Q */
tmppinners = targets & attackers;
pinners |= tmppinners;
//tmpblockers = 0;
/* blockers = we find occupied squares between pinner and king */
bit_for_each64(pinner, tmpbb, tmppinners)
blockers |= bb_between[pinner][king] & tmpblockers;
//blockers |= tmpblockers;
/* same for rook type */
attackers = pos->bb[them][ROOK] | pos->bb[them][QUEEN];
/* targets is all "target" pieces if K was a bishop */
targets = hyperbola_rook_moves(occ, king) & occ;
/* checkers = only opponent B/Q */
tmpcheckers = targets & attackers;
checkers |= tmpcheckers;
/* maybe blockers = not checkers */
tmpblockers = targets & ~tmpcheckers;
/* we find second targets, by removing only first ones (excl. checkers) */
targets = hyperbola_rook_moves(occ ^ tmpblockers, king) ^ tmpcheckers;
/* pinners = only B/Q */
tmppinners = targets & attackers;
pinners |= tmppinners;
//tmpblockers = 0;
/* blockers = we find occupied squares between pinner and king */
bit_for_each64(pinner, tmpbb, tmppinners)
blockers |= bb_between[pinner][king] & tmpblockers;
//blockers |= tmpblockers;
/* pawns */
attackers = pos->bb[them][PAWN];
targets = pawn_shift_upleft(king_bb, us) | pawn_shift_upright(king_bb, us);
checkers |= targets & attackers;
/* knight */
attackers = pos->bb[them][KNIGHT];
targets = bb_knight_moves(attackers, king);
checkers |= targets;
pos->checkers = checkers;
pos->pinners = pinners;
pos->blockers = blockers;
}
/**
* pos_set_pinners_blockers() - set position pinners and blockers.