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#define MOVES_INTERNAL
#include "engine/moves.h"
static bool pawn_attacks_square(position_t position, square_t square, u8 by_color) {
bitboard_t enemy_pawns;
if (by_color == WHITE_TURN) {
enemy_pawns = position.bitboards[WHITE_PAWN];
if (square < 8) return false;
bitboard_t nw = (square % 8 == 7) ? 0 : (enemy_pawns >> (square - 7));
bitboard_t ne = (square % 8 == 0) ? 0 : (enemy_pawns >> (square - 9));
return (nw | ne) & 1;
} else {
enemy_pawns = position.bitboards[BLACK_PAWN];
if (square > 54) return false;
bitboard_t se = (square % 8 == 0) ? 0 : (enemy_pawns >> (square + 7));
bitboard_t sw = (square % 8 == 7) ? 0 : (enemy_pawns >> (square + 9));
return (se | sw) & 1;
}
}
static bool knight_attacks_square(position_t position, square_t square, u8 by_color) {
bitboard_t enemy_knights = (by_color == WHITE_TURN)
? position.bitboards[WHITE_KNIGHT]
: position.bitboards[BLACK_KNIGHT];
return knight_moves[square] & enemy_knights;
}
static bool king_attacks_square(position_t position, square_t square, u8 by_color) {
bitboard_t enemy_king = (by_color == WHITE_TURN)
? position.bitboards[WHITE_KING]
: position.bitboards[BLACK_KING];
bitboard_t movement;
if (square >= 10) {
movement = 920078ULL << (square - 10);
} else {
movement = 920078ULL >> -(square - 10);
}
if ((bitboard_t)1 << square & BITMASK_FILE_A) {
movement &= BITMASK_FILE_A | BITMASK_FILE_B;
} else if ((bitboard_t)1 << square & BITMASK_FILE_H) {
movement &= BITMASK_FILE_G | BITMASK_FILE_H;
}
return movement & enemy_king;
}
static bool sliding_attacks_square(
position_t position,
square_t square,
u8 by_color,
bool check_rook,
bool check_bishop
) {
bitboard_t all_occupied = whites(position) | blacks(position);
int rank = square / 8;
int file = square % 8;
bitboard_t enemy_rooks = (by_color == WHITE_TURN) ? position.bitboards[WHITE_ROOK] : position.bitboards[BLACK_ROOK];
bitboard_t enemy_bishops = (by_color == WHITE_TURN) ? position.bitboards[WHITE_BISHOP] : position.bitboards[BLACK_BISHOP];
bitboard_t enemy_queens = (by_color == WHITE_TURN) ? position.bitboards[WHITE_QUEEN] : position.bitboards[BLACK_QUEEN];
if (check_rook) {
bitboard_t rook_like = enemy_rooks | enemy_queens;
int r, idx;
r = rank + 1;
while (r < 8) {
idx = r * 8 + file;
if ((all_occupied >> idx) & 1) {
if ((rook_like >> idx) & 1) return true;
break;
}
r++;
}
r = rank - 1;
while (r >= 0) {
idx = r * 8 + file;
if ((all_occupied >> idx) & 1) {
if ((rook_like >> idx) & 1) return true;
break;
}
r--;
}
int f = file + 1;
while (f < 8) {
idx = rank * 8 + f;
if ((all_occupied >> idx) & 1) {
if ((rook_like >> idx) & 1) return true;
break;
}
f++;
}
f = file - 1;
while (f >= 0) {
idx = rank * 8 + f;
if ((all_occupied >> idx) & 1) {
if ((rook_like >> idx) & 1) return true;
break;
}
f--;
}
}
if (check_bishop) {
bitboard_t bishop_like = enemy_bishops | enemy_queens;
int r, f, idx;
r = rank + 1; f = file + 1;
while (r < 8 && f < 8) {
idx = r * 8 + f;
if ((all_occupied >> idx) & 1) {
if ((bishop_like >> idx) & 1) return true;
break;
}
r++; f++;
}
r = rank - 1; f = file - 1;
while (r >= 0 && f >= 0) {
idx = r * 8 + f;
if ((all_occupied >> idx) & 1) {
if ((bishop_like >> idx) & 1) return true;
break;
}
r--; f--;
}
r = rank - 1; f = file + 1;
while (r >= 0 && f < 8) {
idx = r * 8 + f;
if ((all_occupied >> idx) & 1) {
if ((bishop_like >> idx) & 1) return true;
break;
}
r--; f++;
}
r = rank + 1; f = file - 1;
while (r < 8 && f >= 0) {
idx = r * 8 + f;
if ((all_occupied >> idx) & 1) {
if ((bishop_like >> idx) & 1) return true;
break;
}
r++; f--;
}
}
return false;
}
bool square_attacked(position_t position, square_t square, u8 by_color) {
if (pawn_attacks_square(position, square, by_color)) return true;
if (knight_attacks_square(position, square, by_color)) return true;
if (king_attacks_square(position, square, by_color)) return true;
if (sliding_attacks_square(position, square, by_color, true, true)) return true;
return false;
}
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