U64 hash_piece_key(S32 piece, S32 square) {
ASSERT(piece_is_ok(piece));
ASSERT(SQUARE_IS_OK(square));
return RANDOM_64(RandomPiece + (PIECE_TO_12(piece) ^ 1) * 64 + SQUARE_TO_64(square)); // HACK: ^1 for PolyGlot book
}
bool piece_attack(const board_t * board, int piece, int from, int to) {
int delta;
int inc, sq;
ASSERT(board_is_ok(board));
ASSERT(piece_is_ok(piece));
ASSERT(square_is_ok(from));
ASSERT(square_is_ok(to));
delta = to - from;
ASSERT(delta_is_ok(delta));
if ((piece & DELTA_MASK(delta)) == 0) return false; // no pseudo-attack
if (!piece_is_slider(piece)) return true;
inc = DELTA_INC(delta);
ASSERT(inc_is_ok(inc));
for (sq = from+inc; sq != to; sq += inc) {
ASSERT(square_is_ok(sq));
if (board->square[sq] != Empty) return false; // blocker
}
return true;
}
int History::move_ordering_score(Piece p, Square to) const {
assert(piece_is_ok(p));
assert(square_is_ok(to));
return history[p][to];
}
static void alists_hidden(alists_t * alists, const board_t * board, int from, int to) {
int inc;
int sq, piece;
ASSERT(alists!=NULL);
ASSERT(board!=NULL);
ASSERT(SQUARE_IS_OK(from));
ASSERT(SQUARE_IS_OK(to));
inc = DELTA_INC_LINE(to-from);
if (inc != IncNone) { // line
sq = from;
do sq -= inc; while ((piece=board->square[sq]) == Empty);
if (SLIDER_ATTACK(piece,inc)) {
ASSERT(piece_is_ok(piece));
ASSERT(PIECE_IS_SLIDER(piece));
alist_add(alists->alist[PIECE_COLOUR(piece)],sq,board);
}
}
}
bool piece_attack_king(const board_t * board, int piece, int from, int king) {
const inc_t * inc_ptr;
int code;
const int * delta_ptr;
int delta, inc;
int to;
int sq;
ASSERT(board!=NULL);
ASSERT(piece_is_ok(piece));
ASSERT(SQUARE_IS_OK(from));
ASSERT(SQUARE_IS_OK(king));
inc_ptr = PIECE_INC(piece);
code = PieceCode[piece];
ASSERT(code>=0&&code<4);
if (PIECE_IS_SLIDER(piece)) {
for (delta_ptr = PieceDeltaDelta[code][DeltaOffset+(king-from)]; (delta=*delta_ptr) != DeltaNone; delta_ptr++) {
ASSERT(delta_is_ok(delta));
inc = DeltaIncLine[DeltaOffset+delta];
ASSERT(inc!=IncNone);
to = from + delta;
sq = from;
do {
sq += inc;
// if (sq == to && SQUARE_IS_OK(to)) {
// ASSERT(DISTANCE(to,king)==1);
// return true;
if (DISTANCE(sq,king)<=2){
return true;
}
} while (board->square[sq] == Empty);
}
} else { // non-slider
for (delta_ptr = PieceDeltaDelta[code][DeltaOffset+(king-from)]; (delta=*delta_ptr) != DeltaNone; delta_ptr++) {
ASSERT(delta_is_ok(delta));
to = from + delta;
if (SQUARE_IS_OK(to)) {
ASSERT(DISTANCE(to,king)==1);
return true;
}
}
}
return false;
}
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));
}
void History::success(Piece p, Square to, Depth d) {
assert(piece_is_ok(p));
assert(square_is_ok(to));
history[p][to] += int(d) * int(d);
// Prevent history overflow
if (history[p][to] >= HistoryMax)
for (int i = 0; i < 16; i++)
for (int j = 0; j < 64; j++)
history[i][j] /= 2;
}
void History::failure(Piece p, Square to, Depth d) {
assert(piece_is_ok(p));
assert(square_is_ok(to));
history[p][to] -= int(d) * int(d);
// Prevent history underflow
if (history[p][to] <= -HistoryMax)
for (int i = 0; i < 16; i++)
for (int j = 0; j < 64; j++)
history[i][j] /= 2;
}
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));
}
static int see_rec(alists_t * alists, const board_t * board, int colour, int to, int piece_value) {
int from, piece;
int value;
ASSERT(alists!=NULL);
ASSERT(board!=NULL);
ASSERT(COLOUR_IS_OK(colour));
ASSERT(SQUARE_IS_OK(to));
ASSERT(piece_value>0);
// find the least valuable attacker
from = alist_pop(alists->alist[colour],board);
if (from == SquareNone) return 0; // no more attackers
// find hidden attackers
alists_hidden(alists,board,from,to);
// calculate the capture value
value = +piece_value; // captured piece
if (value == ValueKing) return value; // do not allow an answer to a king capture
piece = board->square[from];
ASSERT(piece_is_ok(piece));
ASSERT(COLOUR_IS(piece,colour));
piece_value = VALUE_PIECE(piece);
// promote
if (piece_value == ValuePawn && SQUARE_IS_PROMOTE(to)) { // HACK: PIECE_IS_PAWN(piece)
ASSERT(PIECE_IS_PAWN(piece));
piece_value = ValueQueen;
value += ValueQueen - ValuePawn;
}
value -= see_rec(alists,board,COLOUR_OPP(colour),to,piece_value);
if (value < 0) value = 0;
return value;
}
int see_square(const board_t * board, int to, int colour) {
int att, def;
alists_t alists[1];
alist_t * alist;
int piece_value;
int piece;
ASSERT(board!=NULL);
ASSERT(SQUARE_IS_OK(to));
ASSERT(COLOUR_IS_OK(colour));
ASSERT(COLOUR_IS(board->square[to],COLOUR_OPP(colour)));
// build attacker list
att = colour;
alist = alists->alist[att];
ALIST_CLEAR(alist);
alist_build(alist,board,to,att);
if (alist->size == 0) return 0; // no attacker => stop SEE
// build defender list
def = COLOUR_OPP(att);
alist = alists->alist[def];
ALIST_CLEAR(alist);
alist_build(alist,board,to,def);
// captured piece
piece = board->square[to];
ASSERT(piece_is_ok(piece));
ASSERT(COLOUR_IS(piece,def));
piece_value = VALUE_PIECE(piece);
// SEE search
return see_rec(alists,board,att,to,piece_value);
}
bool piece_is_pawn(int piece) {
ASSERT(piece_is_ok(piece));
return (piece & PawnFlags) != 0;
}
int piece_to_char(int piece) {
ASSERT(piece_is_ok(piece));
return PieceString[PIECE_TO_12(piece)];
}
bool piece_is_knight(int piece) {
ASSERT(piece_is_ok(piece));
return (piece & KnightFlag) != 0;
}
bool piece_is_rook(int piece) {
ASSERT(piece_is_ok(piece));
return (piece & QueenFlags) == RookFlag;
}
bool piece_is_bishop(int piece) {
ASSERT(piece_is_ok(piece));
return (piece & QueenFlags) == BishopFlag;
}
bool board_is_ok(const board_t * board) {
int sq, piece, colour;
int size, pos;
if (board == NULL) return false;
// optional heavy DEBUG mode
if (!UseSlowDebug) return true;
// squares
for (sq = 0; sq < SquareNb; sq++) {
piece = board->square[sq];
pos = board->pos[sq];
if (SQUARE_IS_OK(sq)) {
// inside square
if (piece == Empty) {
if (pos != -1) return false;
} else {
if (!piece_is_ok(piece)) return false;
if (!PIECE_IS_PAWN(piece)) {
colour = PIECE_COLOUR(piece);
if (pos < 0 || pos >= board->piece_size[colour]) return false;
if (board->piece[colour][pos] != sq) return false;
} else { // pawn
if (SQUARE_IS_PROMOTE(sq)) return false;
colour = PIECE_COLOUR(piece);
if (pos < 0 || pos >= board->pawn_size[colour]) return false;
if (board->pawn[colour][pos] != sq) return false;
}
}
} else {
// edge square
if (piece != Edge) return false;
if (pos != -1) return false;
}
}
// piece lists
for (colour = 0; colour < ColourNb; colour++) {
// piece list
size = board->piece_size[colour];
if (size < 1 || size > 16) return false;
for (pos = 0; pos < size; pos++) {
sq = board->piece[colour][pos];
if (!SQUARE_IS_OK(sq)) return false;
if (board->pos[sq] != pos) return false;
piece = board->square[sq];
if (!COLOUR_IS(piece,colour)) return false;
if (pos == 0 && !PIECE_IS_KING(piece)) return false;
if (pos != 0 && PIECE_IS_KING(piece)) return false;
if (pos != 0 && PIECE_ORDER(piece) > PIECE_ORDER(board->square[board->piece[colour][pos-1]])) {
return false;
}
}
sq = board->piece[colour][size];
if (sq != SquareNone) return false;
// pawn list
size = board->pawn_size[colour];
if (size < 0 || size > 8) return false;
for (pos = 0; pos < size; pos++) {
sq = board->pawn[colour][pos];
if (!SQUARE_IS_OK(sq)) return false;
if (SQUARE_IS_PROMOTE(sq)) return false;
if (board->pos[sq] != pos) return false;
piece = board->square[sq];
if (!COLOUR_IS(piece,colour)) return false;
if (!PIECE_IS_PAWN(piece)) return false;
}
sq = board->pawn[colour][size];
if (sq != SquareNone) return false;
// piece total
if (board->piece_size[colour] + board->pawn_size[colour] > 16) return false;
}
// material
if (board->piece_nb != board->piece_size[White] + board->pawn_size[White]
+ board->piece_size[Black] + board->pawn_size[Black]) {
return false;
}
if (board->number[WhitePawn12] != board->pawn_size[White]) return false;
if (board->number[BlackPawn12] != board->pawn_size[Black]) return false;
if (board->number[WhiteKing12] != 1) return false;
if (board->number[BlackKing12] != 1) return false;
// misc
if (!COLOUR_IS_OK(board->turn)) return false;
if (board->ply_nb < 0) return false;
if (board->sp < board->ply_nb) return false;
if (board->cap_sq != SquareNone && !SQUARE_IS_OK(board->cap_sq)) return false;
if (board->opening != board_opening(board)) return false;
if (board->endgame != board_endgame(board)) return false;
if (board->key != hash_key(board)) return false;
if (board->pawn_key != hash_pawn_key(board)) return false;
if (board->material_key != hash_material_key(board)) return false;
return true;
}
bool piece_is_queen(int piece) {
ASSERT(piece_is_ok(piece));
return (piece & QueenFlags) == QueenFlags;
}
static void square_move(board_t * board, int from, int to, int piece, bool update) {
int colour;
int pos;
int from_64, to_64;
int piece_12;
int piece_index;
uint64 hash_xor;
ASSERT(board!=NULL);
ASSERT(SQUARE_IS_OK(from));
ASSERT(SQUARE_IS_OK(to));
ASSERT(piece_is_ok(piece));
ASSERT(update==true||update==false);
// 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
if (!PIECE_IS_PAWN(piece)) {
ASSERT(board->piece[colour][pos]==from);
board->piece[colour][pos] = to;
} else {
ASSERT(board->pawn[colour][pos]==from);
board->pawn[colour][pos] = to;
// pawn "bitboard"
board->pawn_file[colour][SQUARE_FILE(from)] ^= BIT(PAWN_RANK(from,colour));
board->pawn_file[colour][SQUARE_FILE(to)] ^= BIT(PAWN_RANK(to,colour));
}
// update
if (update) {
// init
from_64 = SQUARE_TO_64(from);
to_64 = SQUARE_TO_64(to);
piece_12 = PIECE_TO_12(piece);
// PST
board->opening += PST(piece_12,to_64,Opening) - PST(piece_12,from_64,Opening);
board->endgame += PST(piece_12,to_64,Endgame) - PST(piece_12,from_64,Endgame);
// hash key
piece_index = RandomPiece + (piece_12^1) * 64; // HACK: ^1 for PolyGlot book
hash_xor = RANDOM_64(piece_index+to_64) ^ RANDOM_64(piece_index+from_64);
board->key ^= hash_xor;
if (PIECE_IS_PAWN(piece)) board->pawn_key ^= hash_xor;
}
}
void board_init_list(board_t * board) {
int sq_64, sq, piece;
int colour, pos;
int i, size;
int square;
int order;
int file;
ASSERT(board!=NULL);
// init
for (sq = 0; sq < SquareNb; sq++) {
board->pos[sq] = -1;
}
board->piece_nb = 0;
for (piece = 0; piece < 12; piece++) board->number[piece] = 0;
// piece lists
for (colour = 0; colour < ColourNb; colour++) {
// piece list
pos = 0;
for (sq_64 = 0; sq_64 < 64; sq_64++) {
sq = SQUARE_FROM_64(sq_64);
piece = board->square[sq];
if (piece != Empty && !piece_is_ok(piece)) my_fatal("board_init_list(): illegal position\n");
if (COLOUR_IS(piece,colour) && !PIECE_IS_PAWN(piece)) {
if (pos >= 16) my_fatal("board_init_list(): illegal position\n");
ASSERT(pos>=0&&pos<16);
board->pos[sq] = pos;
board->piece[colour][pos] = sq;
pos++;
board->piece_nb++;
board->number[PIECE_TO_12(piece)]++;
}
}
if (board->number[COLOUR_IS_WHITE(colour)?WhiteKing12:BlackKing12] != 1) my_fatal("board_init_list(): illegal position\n");
ASSERT(pos>=1&&pos<=16);
board->piece[colour][pos] = SquareNone;
board->piece_size[colour] = pos;
// MV sort
size = board->piece_size[colour];
for (i = 1; i < size; i++) {
square = board->piece[colour][i];
piece = board->square[square];
order = PIECE_ORDER(piece);
for (pos = i; pos > 0 && order > PIECE_ORDER(board->square[(sq=board->piece[colour][pos-1])]); pos--) {
ASSERT(pos>0&&pos<size);
board->piece[colour][pos] = sq;
ASSERT(board->pos[sq]==pos-1);
board->pos[sq] = pos;
}
ASSERT(pos>=0&&pos<size);
board->piece[colour][pos] = square;
ASSERT(board->pos[square]==i);
board->pos[square] = pos;
}
// debug
if (DEBUG) {
for (i = 0; i < board->piece_size[colour]; i++) {
sq = board->piece[colour][i];
ASSERT(board->pos[sq]==i);
if (i == 0) { // king
ASSERT(PIECE_IS_KING(board->square[sq]));
} else {
ASSERT(!PIECE_IS_KING(board->square[sq]));
ASSERT(PIECE_ORDER(board->square[board->piece[colour][i]])<=PIECE_ORDER(board->square[board->piece[colour][i-1]]));
}
}
}
// pawn list
for (file = 0; file < FileNb; file++) {
board->pawn_file[colour][file] = 0;
}
pos = 0;
for (sq_64 = 0; sq_64 < 64; sq_64++) {
sq = SQUARE_FROM_64(sq_64);
piece = board->square[sq];
if (COLOUR_IS(piece,colour) && PIECE_IS_PAWN(piece)) {
if (pos >= 8 || SQUARE_IS_PROMOTE(sq)) my_fatal("board_init_list(): illegal position\n");
ASSERT(pos>=0&&pos<8);
board->pos[sq] = pos;
board->pawn[colour][pos] = sq;
pos++;
board->piece_nb++;
board->number[PIECE_TO_12(piece)]++;
board->pawn_file[colour][SQUARE_FILE(sq)] |= BIT(PAWN_RANK(sq,colour));
}
}
ASSERT(pos>=0&&pos<=8);
board->pawn[colour][pos] = SquareNone;
board->pawn_size[colour] = pos;
if (board->piece_size[colour] + board->pawn_size[colour] > 16) my_fatal("board_init_list(): illegal position\n");
}
// last square
board->cap_sq = SquareNone;
// PST
board->opening = board_opening(board);
board->endgame = board_endgame(board);
// hash key
for (i = 0; i < board->ply_nb; i++) board->stack[i] = 0; // HACK
board->sp = board->ply_nb;
board->key = hash_key(board);
board->pawn_key = hash_pawn_key(board);
board->material_key = hash_material_key(board);
// legality
if (!board_is_legal(board)) my_fatal("board_init_list(): illegal position\n");
// debug
ASSERT(board_is_ok(board));
}
bool piece_is_king(int piece) {
ASSERT(piece_is_ok(piece));
return (piece & KingFlag) != 0;
}
bool piece_is_slider(int piece) {
ASSERT(piece_is_ok(piece));
return (piece & QueenFlags) != 0;
}
int piece_to_12(int piece) {
ASSERT(piece_is_ok(piece));
return PieceTo12[piece];
}
int piece_type(int piece) {
ASSERT(piece_is_ok(piece));
return piece & ~3;
}
int piece_colour(int piece) {
ASSERT(piece_is_ok(piece));
return piece & 3;
}
int see_move(int move, const board_t * board) {
int att, def;
int from, to;
alists_t alists[1];
int value, piece_value;
int piece, capture;
alist_t * alist;
int pos;
ASSERT(move_is_ok(move));
ASSERT(board!=NULL);
// init
from = MOVE_FROM(move);
to = MOVE_TO(move);
// move the piece
piece_value = 0;
piece = board->square[from];
ASSERT(piece_is_ok(piece));
att = PIECE_COLOUR(piece);
def = COLOUR_OPP(att);
// promote
if (MOVE_IS_PROMOTE(move)) {
ASSERT(PIECE_IS_PAWN(piece));
piece = move_promote(move);
ASSERT(piece_is_ok(piece));
ASSERT(COLOUR_IS(piece,att));
}
piece_value += VALUE_PIECE(piece);
// clear attacker lists
ALIST_CLEAR(alists->alist[Black]);
ALIST_CLEAR(alists->alist[White]);
// find hidden attackers
alists_hidden(alists,board,from,to);
// capture the piece
value = 0;
capture = board->square[to];
if (capture != Empty) {
ASSERT(piece_is_ok(capture));
ASSERT(COLOUR_IS(capture,def));
value += VALUE_PIECE(capture);
}
// promote
if (MOVE_IS_PROMOTE(move)) {
value += VALUE_PIECE(piece) - ValuePawn;
}
// en-passant
if (MOVE_IS_EN_PASSANT(move)) {
ASSERT(value==0);
ASSERT(PIECE_IS_PAWN(board->square[SQUARE_EP_DUAL(to)]));
value += ValuePawn;
alists_hidden(alists,board,SQUARE_EP_DUAL(to),to);
}
// build defender list
alist = alists->alist[def];
alist_build(alist,board,to,def);
if (alist->size == 0) return value; // no defender => stop SEE
// build attacker list
alist = alists->alist[att];
alist_build(alist,board,to,att);
// remove the moved piece (if it's an attacker)
for (pos = 0; pos < alist->size && alist->square[pos] != from; pos++)
;
if (pos < alist->size) alist_remove(alist,pos);
// SEE search
value -= see_rec(alists,board,def,to,piece_value);
return value;
}
bool move_is_pseudo(int move, board_t * board) {
int me, opp;
int from, to;
int piece, capture;
int inc, delta;
ASSERT(move_is_ok(move));
ASSERT(board!=NULL);
ASSERT(!board_is_check(board));
// special cases
if (MOVE_IS_SPECIAL(move)) {
return move_is_pseudo_debug(move,board);
}
ASSERT((move&~07777)==0);
// init
me = board->turn;
opp = COLOUR_OPP(board->turn);
// from
from = MOVE_FROM(move);
ASSERT(SQUARE_IS_OK(from));
piece = board->square[from];
if (!COLOUR_IS(piece,me)) return false;
ASSERT(piece_is_ok(piece));
// to
to = MOVE_TO(move);
ASSERT(SQUARE_IS_OK(to));
capture = board->square[to];
if (COLOUR_IS(capture,me)) return false;
// move
if (PIECE_IS_PAWN(piece)) {
if (SQUARE_IS_PROMOTE(to)) return false;
inc = PAWN_MOVE_INC(me);
delta = to - from;
ASSERT(delta_is_ok(delta));
if (capture == Empty) {
// pawn push
if (delta == inc) return true;
if (delta == (2*inc)
&& PAWN_RANK(from,me) == Rank2
&& board->square[from+inc] == Empty) {
return true;
}
} else {
// pawn capture
if (delta == (inc-1) || delta == (inc+1)) return true;
}
} else {
if (PIECE_ATTACK(board,piece,from,to)) return true;
}
return false;
}
bool board_to_fen(const board_t * board, char fen[], int size) {
int pos;
int file, rank;
int sq, piece;
int c;
int len;
ASSERT(board!=NULL);
ASSERT(fen!=NULL);
ASSERT(size>=92);
// init
if (size < 92) return false;
pos = 0;
// piece placement
for (rank = Rank8; rank >= Rank1; rank--) {
for (file = FileA; file <= FileH;) {
sq = SQUARE_MAKE(file,rank);
piece = board->square[sq];
ASSERT(piece==Empty||piece_is_ok(piece));
if (piece == Empty) {
len = 0;
for (; file <= FileH && board->square[SQUARE_MAKE(file,rank)] == Empty; file++) {
len++;
}
ASSERT(len>=1&&len<=8);
c = '0' + len;
} else {
c = piece_to_char(piece);
file++;
}
fen[pos++] = c;
}
fen[pos++] = '/';
}
fen[pos-1] = ' '; // HACK: remove the last '/'
// active colour
fen[pos++] = (COLOUR_IS_WHITE(board->turn)) ? 'w' : 'b';
fen[pos++] = ' ';
// castling
if (board->flags == FlagsNone) {
fen[pos++] = '-';
} else {
if ((board->flags & FlagsWhiteKingCastle) != 0) fen[pos++] = 'K';
if ((board->flags & FlagsWhiteQueenCastle) != 0) fen[pos++] = 'Q';
if ((board->flags & FlagsBlackKingCastle) != 0) fen[pos++] = 'k';
if ((board->flags & FlagsBlackQueenCastle) != 0) fen[pos++] = 'q';
}
fen[pos++] = ' ';
// en-passant
if (board->ep_square == SquareNone) {
fen[pos++] = '-';
} else {
square_to_string(board->ep_square,&fen[pos],3);
pos += 2;
}
fen[pos++] = ' ';
// halfmove clock
sprintf(&fen[pos],"%d 1",board->ply_nb);
return true;
}
static void square_set(board_t * board, int square, int piece, int pos, bool update) {
int piece_12, colour;
int sq;
int i, size;
int sq_64;
uint64 hash_xor;
ASSERT(board!=NULL);
ASSERT(SQUARE_IS_OK(square));
ASSERT(piece_is_ok(piece));
ASSERT(pos>=0);
ASSERT(update==true||update==false);
// init
piece_12 = PIECE_TO_12(piece);
colour = PIECE_COLOUR(piece);
// square
ASSERT(board->square[square]==Empty);
board->square[square] = piece;
// piece list
if (!PIECE_IS_PAWN(piece)) {
// init
size = board->piece_size[colour];
ASSERT(size>=0);
// size
size++;
board->piece[colour][size] = SquareNone;
board->piece_size[colour] = size;
// stable swap
ASSERT(pos>=0&&pos<size);
for (i = size-1; i > pos; i--) {
sq = board->piece[colour][i-1];
board->piece[colour][i] = sq;
ASSERT(board->pos[sq]==i-1);
board->pos[sq] = i;
}
board->piece[colour][pos] = square;
ASSERT(board->pos[square]==-1);
board->pos[square] = pos;
} else {
// init
size = board->pawn_size[colour];
ASSERT(size>=0);
// size
size++;
board->pawn[colour][size] = SquareNone;
board->pawn_size[colour] = size;
// stable swap
ASSERT(pos>=0&&pos<size);
for (i = size-1; i > pos; i--) {
sq = board->pawn[colour][i-1];
board->pawn[colour][i] = sq;
ASSERT(board->pos[sq]==i-1);
board->pos[sq] = i;
}
board->pawn[colour][pos] = square;
ASSERT(board->pos[square]==-1);
board->pos[square] = pos;
// pawn "bitboard"
board->pawn_file[colour][SQUARE_FILE(square)] ^= BIT(PAWN_RANK(square,colour));
}
// material
ASSERT(board->piece_nb<32);
board->piece_nb++;;
ASSERT(board->number[piece_12]<9);
board->number[piece_12]++;
// update
if (update) {
// init
sq_64 = SQUARE_TO_64(square);
// PST
board->opening += PST(piece_12,sq_64,Opening);
board->endgame += PST(piece_12,sq_64,Endgame);
// hash key
hash_xor = RANDOM_64(RandomPiece+(piece_12^1)*64+sq_64); // HACK: ^1 for PolyGlot book
board->key ^= hash_xor;
if (PIECE_IS_PAWN(piece)) board->pawn_key ^= hash_xor;
// material key
board->material_key ^= RANDOM_64(piece_12*16+(board->number[piece_12]-1));
}
}
