stellar

Knight attack mask

1 files changed, 20 insertions(+), 1 deletions(-)

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

@@ -119,6 +119,9 @@ void bitboard_print(U64 bitboard) { // pawn attack table [side][square] U64 pawn_attacks[2][64];

// knight attack table [square]

U64 knight_attacks[64];

// generate pawn attack U64 mask_pawn_attacks(int side, int square) { U64 bitboard = C64(0), attacks;

@@ -130,11 +133,27 @@ U64 mask_pawn_attacks(int side, int square) { return soWeOne(bitboard) | soEaOne(bitboard); }

U64 mask_knight_attacks(int square) {

U64 bitboard = C64(0), attacks = C64(0), tmp;

bit_set(bitboard, square);

tmp = nortOne(nortOne(bitboard));

attacks |= westOne(tmp) | eastOne(tmp);

tmp = soutOne(soutOne(bitboard));

attacks |= westOne(tmp) | eastOne(tmp);

tmp = westOne(westOne(bitboard));

attacks |= soutOne(tmp) | nortOne(tmp);

tmp = eastOne(eastOne(bitboard));

attacks |= soutOne(tmp) | nortOne(tmp);

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);

bitboard_print(pawn_attacks[WHITE][square]);

knight_attacks[square] = mask_knight_attacks(square);

} }