bool is_pinned(const board_t * board, int from, int to, int colour) {
int king;
int inc;
int sq, piece;
ASSERT(board!=NULL);
ASSERT(square_is_ok(from));
ASSERT(square_is_ok(to));
ASSERT(colour_is_ok(colour));
king = king_pos(board,colour);
inc = DELTA_INC(king-from);
if (inc == IncNone) return false; // not a line
sq = from;
do sq += inc;
while (board->square[sq] == Empty);
if (sq != king) return false; // blocker
sq = from;
do sq -= inc;
while ((piece=board->square[sq]) == Empty);
return square_is_ok(sq)
&& (piece & DELTA_MASK(king-sq)) != 0
&& piece_colour(piece) == colour_opp(colour)
&& DELTA_INC(king-to) != inc;
}
static void square_clear(board_t * board, int square, int piece) {
int pos, piece_12, colour;
int sq, size;
ASSERT(board!=NULL);
ASSERT(square_is_ok(square));
ASSERT(piece_is_ok(piece));
// init
pos = board->pos[square];
ASSERT(pos>=0);
colour = piece_colour(piece);
piece_12 = piece_to_12(piece);
// square
ASSERT(board->square[square]==piece);
board->square[square] = Empty;
ASSERT(board->pos[square]==pos);
board->pos[square] = -1; // not needed
// piece list
ASSERT(board->variant==Horde?board->list_size[colour]>=1:board->list_size[colour]>=2);
size = --board->list_size[colour];
ASSERT(pos<=size);
if (pos != size) {
sq = board->list[colour][size];
ASSERT(square_is_ok(sq));
ASSERT(sq!=square);
ASSERT(board->pos[sq]==size);
board->pos[sq] = pos;
ASSERT(board->list[colour][pos]==square);
board->list[colour][pos] = sq;
}
board->list[colour][size] = SquareNone;
// material
ASSERT(board->number[piece_12]>=1);
board->number[piece_12]--;
// hash key
board->key ^= random_64(RandomPiece+piece_12*64+square_to_64(square));
}
static void square_set(board_t * board, int square, int piece, int pos) {
int piece_12, colour;
int sq, size;
ASSERT(board!=NULL);
ASSERT(square_is_ok(square));
ASSERT(piece_is_ok(piece));
ASSERT(pos>=0);
// init
colour = piece_colour(piece);
piece_12 = piece_to_12(piece);
// square
ASSERT(board->square[square]==Empty);
board->square[square] = piece;
ASSERT(board->pos[square]==-1);
board->pos[square] = pos;
// piece list
size = board->list_size[colour]++;
ASSERT(board->list[colour][size]==SquareNone);
ASSERT(pos<=size);
if (pos != size) {
sq = board->list[colour][pos];
ASSERT(square_is_ok(sq));
ASSERT(sq!=square);
ASSERT(board->pos[sq]==pos);
board->pos[sq] = size;
ASSERT(board->list[colour][size]==SquareNone);
board->list[colour][size] = sq;
}
board->list[colour][pos] = square;
// material
ASSERT(board->number[piece_12]<=8);
board->number[piece_12]++;
// hash key
board->key ^= random_64(RandomPiece+piece_12*64+square_to_64(square));
}
static void square_move(board_t * board, int from, int to, int piece) {
int colour, pos;
int piece_index;
ASSERT(board!=NULL);
ASSERT(square_is_ok(from));
ASSERT(square_is_ok(to));
ASSERT(piece_is_ok(piece));
// init
colour = piece_colour(piece);
pos = board->pos[from];
ASSERT(pos>=0);
// from
ASSERT(board->square[from]==piece);
board->square[from] = Empty;
ASSERT(board->pos[from]==pos);
board->pos[from] = -1; // not needed
// to
ASSERT(board->square[to]==Empty);
board->square[to] = piece;
ASSERT(board->pos[to]==-1);
board->pos[to] = pos;
// piece list
ASSERT(board->list[colour][pos]==from);
board->list[colour][pos] = to;
// hash key
piece_index = RandomPiece + piece_to_12(piece) * 64;
board->key ^= random_64(piece_index+square_to_64(from))
^ random_64(piece_index+square_to_64(to));
}
bool board_is_ok(const board_t * board) {
int sq, piece;
int colour, pos;
int king, rook;
if (board == NULL) return false;
// optional heavy DEBUG mode
if (!UseSlowDebug) return true;
// squares
for (sq = 0; sq < SquareNb; sq++) {
piece = board->square[sq];
if (square_is_ok(sq)) {
pos = board->pos[sq];
if (piece == Empty) {
if (pos != -1) return false;
} else {
if (pos < 0) return false;
if (board->list[piece_colour(piece)][pos] != sq) return false;
}
} else {
if (piece != Knight64) return false;
}
}
// white piece list
colour = White;
pos = 0;
if (board->list_size[colour] <= 0 || board->list_size[colour] > 16) return false;
sq = board->list[colour][pos];
if (sq == SquareNone) return false;
if (board->pos[sq] != pos) return false;
piece = board->square[sq];
if (!colour_equal(piece,colour) || !piece_is_king(piece)) return false;
for (pos++; pos < board->list_size[colour]; pos++) {
sq = board->list[colour][pos];
if (sq == SquareNone) return false;
if (board->pos[sq] != pos) return false;
if (!colour_equal(board->square[sq],colour)) return false;
}
sq = board->list[colour][pos];
if (sq != SquareNone) return false;
// black piece list
colour = Black;
pos = 0;
if (board->list_size[colour] <= 0 || board->list_size[colour] > 16) return false;
sq = board->list[colour][pos];
if (sq == SquareNone) return false;
if (board->pos[sq] != pos) return false;
piece = board->square[sq];
if (!colour_equal(piece,colour) || !piece_is_king(piece)) return false;
for (pos++; pos < board->list_size[colour]; pos++) {
sq = board->list[colour][pos];
if (sq == SquareNone) return false;
if (board->pos[sq] != pos) return false;
if (!colour_equal(board->square[sq],colour)) return false;
}
sq = board->list[colour][pos];
if (sq != SquareNone) return false;
// TODO: material
if (board->number[WhiteKing12] != 1) return false;
if (board->number[BlackKing12] != 1) return false;
if (!colour_is_ok(board->turn)) return false;
// castling status
if (board->castle[White][SideH] != SquareNone) {
king = board->list[White][0];
if (king < A1 || king > H1) return false;
if (board->square[king] != WhiteKing256) return false;
rook = board->castle[White][SideH];
if (rook < A1 || rook > H1) return false;
if (board->square[rook] != WhiteRook256) return false;
if (rook <= king) return false;
}
if (board->castle[White][SideA] != SquareNone) {
king = board->list[White][0];
if (king < A1 || king > H1) return false;
if (board->square[king] != WhiteKing256) return false;
rook = board->castle[White][SideA];
if (rook < A1 || rook > H1) return false;
if (board->square[rook] != WhiteRook256) return false;
if (rook >= king) return false;
}
if (board->castle[Black][SideH] != SquareNone) {
king = board->list[Black][0];
if (king < A8 || king > H8) return false;
if (board->square[king] != BlackKing256) return false;
rook = board->castle[Black][SideH];
if (rook < A8 || rook > H8) return false;
if (board->square[rook] != BlackRook256) return false;
if (rook <= king) return false;
}
if (board->castle[Black][SideA] != SquareNone) {
king = board->list[Black][0];
if (king < A8 || king > H8) return false;
if (board->square[king] != BlackKing256) return false;
rook = board->castle[Black][SideA];
if (rook < A8 || rook > H8) return false;
if (board->square[rook] != BlackRook256) return false;
if (rook >= king) return false;
}
return true;
}
bool board_from_fen(board_t * board, const char string[]) {
int pos;
int file, rank, sq;
int c;
int i, len;
int piece;
int king_pos[ColourNb];
ASSERT(board!=NULL);
ASSERT(string!=NULL);
board_clear(board);
king_pos[White] = SquareNone;
king_pos[Black] = SquareNone;
pos = 0;
c = string[pos];
// piece placement
for (rank = 7; rank >= 0; rank--) {
for (file = 0; file < 8;) {
sq = square_make(file,rank);
if (c >= '1' && c <= '8') { // empty square(s)
len = c - '0';
if (file + len > 8) my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos);
for (i = 0; i < len; i++) {
board->square[sq++] = Empty;
file++;
}
} else { // piece
piece = piece_from_char(c);
if (piece == PieceNone256) my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos);
if (piece_is_king(piece)) king_pos[piece_colour(piece)] = sq;
board->square[sq++] = piece;
file++;
}
c = string[++pos];
}
if (rank > 0) {
if (c != '/') my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos);
c = string[++pos];
}
}
// active colour
if (c != ' ') my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos);
c = string[++pos];
switch (c) {
case 'w':
board->turn = White;
break;
case 'b':
board->turn = Black;
break;
default:
my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos);
break;
}
c = string[++pos];
// castling
if (c != ' ') my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos);
c = string[++pos];
board->castle[White][SideH] = SquareNone;
board->castle[White][SideA] = SquareNone;
board->castle[Black][SideH] = SquareNone;
board->castle[Black][SideA] = SquareNone;
if (c == '-') { // no castling rights
c = string[++pos];
} else {
// TODO: filter out illegal rights
do {
if (false) {
} else if (c == 'K') {
for (sq = H1; sq > king_pos[White]; sq--) {
if (board->square[sq] == WhiteRook256) {
board->castle[White][SideH] = sq;
break;
}
}
} else if (c == 'Q') {
for (sq = A1; sq < king_pos[White]; sq++) {
if (board->square[sq] == WhiteRook256) {
board->castle[White][SideA] = sq;
break;
}
}
} else if (c == 'k') {
for (sq = H8; sq > king_pos[Black]; sq--) {
if (board->square[sq] == BlackRook256) {
board->castle[Black][SideH] = sq;
break;
}
}
} else if (c == 'q') {
for (sq = A8; sq < king_pos[Black]; sq++) {
if (board->square[sq] == BlackRook256) {
board->castle[Black][SideA] = sq;
break;
}
}
} else if (c >= 'A' && c <= 'H') {
// white castling right
sq = square_make(file_from_char(tolower(c)),Rank1);
if (sq > king_pos[White]) { // h side
board->castle[White][SideH] = sq;
} else { // a side
board->castle[White][SideA] = sq;
}
} else if (c >= 'a' && c <= 'h') {
// black castling right
sq = square_make(file_from_char(tolower(c)),Rank8);
if (sq > king_pos[Black]) { // h side
board->castle[Black][SideH] = sq;
} else { // a side
board->castle[Black][SideA] = sq;
}
} else {
my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos);
}
c = string[++pos];
} while (c != ' ');
}
// en-passant
if (c != ' ') my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos);
c = string[++pos];
if (c == '-') { // no en-passant
sq = SquareNone;
c = string[++pos];
} else {
if (c < 'a' || c > 'h') my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos);
file = file_from_char(c);
c = string[++pos];
if (c < '1' || c > '8') my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos);
rank = rank_from_char(c);
c = string[++pos];
sq = square_make(file,rank);
}
board->ep_square = sq;
// halfmove clock
board->ply_nb = 0;
board->move_nb = 0; // HACK, in case of broken syntax
if (c != ' ') {
if (!Strict) goto update;
my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos);
}
c = string[++pos];
if (!isdigit(c)) {
if (!Strict) goto update;
my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos);
}
board->ply_nb = atoi(&string[pos]);
do c = string[++pos]; while (isdigit(c));
// fullmove number
board->move_nb = 0;
if (c != ' ') {
if (!Strict) goto update;
my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos);
}
c = string[++pos];
if (!isdigit(c)) {
if (!Strict) goto update;
my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos);
}
board->move_nb = atoi(&string[pos]) - 1;
do c = string[++pos]; while (isdigit(c));
// board update
update:
board_init_list(board);
return true;
}
