stellar

UCI Chess engine written in C++20
git clone git://git.dimitrijedobrota.com/stellar.git
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commita1e1fde71226015465fd0dacbf438af066a8f5c7
parent7ee440bb0ac6b207d99d69730ba6002bb908d96c
authorDimitrije Dobrota <mail@dimitrijedobrota.com>
dateMon, 19 Sep 2022 17:26:16 +0200

King attack mask

Diffstat:
Msrc/engine.c|+++++++++++++++++

1 files changed, 17 insertions(+), 0 deletions(-)

diff --git a/src/engine.c b/src/engine.c

@@ -122,6 +122,9 @@ U64 pawn_attacks[2][64];

// knight attack table [square]
U64 knight_attacks[64];
// king attack table [square]
U64 king_attacks[64];
// generate pawn attack
U64 mask_pawn_attacks(int side, int square) {
U64 bitboard = C64(0), attacks;

@@ -149,11 +152,25 @@ U64 mask_knight_attacks(int square) {

return attacks;
}
U64 mask_king_attacks(int square) {
U64 bitboard = C64(0), attacks = C64(0);
bit_set(bitboard, square);
attacks |= westOne(bitboard) | eastOne(bitboard);
attacks |= soutOne(bitboard) | nortOne(bitboard);
attacks |= soutOne(bitboard) | nortOne(bitboard);
attacks |= soEaOne(bitboard) | noEaOne(bitboard);
attacks |= soWeOne(bitboard) | noWeOne(bitboard);
return attacks;
}
void init_leapers_attacks(void) {
for (int square = 0; square < 64; square++) {
pawn_attacks[WHITE][square] = mask_pawn_attacks(WHITE, square);
pawn_attacks[BLACK][square] = mask_pawn_attacks(BLACK, square);
knight_attacks[square] = mask_knight_attacks(square);
king_attacks[square] = mask_king_attacks(square);
}
}