int get_next_tetri(int const fd, t_list **head, char letter)
{
int ret;
char buf[22];
int resval;
ret = read(fd, buf, 21);
buf[ret] = '\0';
if (!(resval = is_valid(buf)) && *buf)
return (0);
if (ret != 0)
create_piece(head, buf, letter);
return (ret);
}
/*
* Fill the provided list with all pseudolegal captures in the given position.
*/
static int generate_pseudo_captures(const position_t* pos, move_t* moves)
{
move_t* moves_head = moves;
color_t side = pos->side_to_move;
piece_t piece;
square_t from;
for (int i = 0; i < pos->num_pieces[side]; ++i) {
from = pos->pieces[side][i];
piece = pos->board[from];
generate_piece_captures(pos, from, piece, &moves);
}
piece = create_piece(side, PAWN);
for (int i=0; i<pos->num_pawns[side]; ++i) {
from = pos->pawns[side][i];
generate_pawn_captures(pos, from, piece, &moves);
}
*moves = 0;
return moves-moves_head;
}
/*
* Add all pseudo-legal non-capturing promotions.
*/
static int generate_promotions(const position_t* pos, move_t* moves)
{
move_t* moves_head = moves;
color_t side = pos->side_to_move;
piece_t piece = create_piece(side, PAWN);
for (int i = 0; i < pos->num_pawns[side]; ++i) {
square_t from = pos->pawns[side][i];
rank_t r_rank = relative_rank[side][square_rank(from)];
if (r_rank < RANK_7) continue;
square_t to = from + pawn_push[side];
if (pos->board[to]) continue;
for (piece_type_t type=KNIGHT; type<=QUEEN; ++type) {
moves = add_move(pos,
create_move_promote(from, to, piece, EMPTY, type),
moves);
}
}
*moves = 0;
return (moves-moves_head);
}
static void init_army_pieces( army_type * owner )
{
unsigned int row = 7*(1-owner->colour);
// piece[0].Init( this, row, 3, 4 ); ...
create_piece( owner, row, 3, 4 ); // Queen
create_piece( owner, row, 0, 3 ); // Rooks
create_piece( owner, row, 7, 3 );
create_piece( owner, row, 2, 2 ); // Bishops
create_piece( owner, row, 5, 2 );
create_piece( owner, row, 1, 1 ); // Knights
create_piece( owner, row, 6, 1 );
create_piece( owner, row, 4, 5 ); // King
row = 5*(1-owner->colour)+1;
create_piece( owner, row, 0, 0 ); // Pawns
create_piece( owner, row, 1, 0 );
create_piece( owner, row, 2, 0 );
create_piece( owner, row, 3, 0 );
create_piece( owner, row, 4, 0 );
create_piece( owner, row, 5, 0 );
create_piece( owner, row, 6, 0 );
create_piece( owner, row, 7, 0 );
} // init_army_pieces()
static void construct_study( army_type army[] )
{
char str[10];
unsigned int i, row, col, pc_num, colour;
army_type * owner;
piece_type * pc;
close_open_book( army->sh );
// Automatically create the 2 kings,
// prompting user for coords
for( i = 0; i < 2; i++ ) {
owner = &army[i];
do {
printf( "Coordinates of %s king: ",
owner->name );
scanf( "%s", str );
} while( !coord_ext_to_int( str, &row, &col )
|| !create_piece( owner, row, col, 5 ) );
if( row != 7*(1-i) || col != 4 ) {
printf( "Castling disallowed for %s\n", owner->name );
owner->castle_lost[0] = owner->castle_lost[1] = 0;
}
}
/* Allow creation of extra pieces */
for( ; ; ) {
print_board( army );
for( i = 0; i < NUM_PIECE_DEFS; i++ ) {
printf( "%d: %s ", i,
army->sh->pc_def[i].name );
}
printf( "\nCreate which piece (-1 to exit): " );
scanf( "%d", &pc_num );
if( pc_num >= NUM_PIECE_DEFS ) break;
do {
printf( "Colour (white=%d, black=%d): ",
O_WHITE, O_BLACK );
scanf( "%d", &colour );
} while( colour >= 2 );
owner = &army[colour];
if( owner->num_pieces >= MAX_ARMY_SIZE ) {
printf( "%s already has %d pieces\n",
owner->name, owner->num_pieces );
continue;
}
do {
printf( "Coordinates: " );
scanf( "%s", str );
} while( !coord_ext_to_int( str, &row, &col )
|| !create_piece( owner, row, col, pc_num ) );
}
// Check rooks for castling
for( colour = 0; colour <= 1; colour++ ) { // Army num
owner = &army[colour];
for( i = 0; i <= 1; i++ ) { // Castle type
if( owner->castle_lost[i] == 0 ) continue;
pc = read_board(owner,7*(1-colour),7*(1-i));
if( pc == NULL || pc->owner != owner
|| pc->def->token != ROOK_TOKEN ) {
printf( "%sside castling disallowed for %s\n",
(i == 0) ? "King" : "Queen", owner->name );
owner->castle_lost[i] = 0;
}
}
}
} // construct_study()
/*
* Generate all moves that evade check in the given position. This is purely
* legal move generation; no pseudo-legal moves.
*/
int generate_evasions(const position_t* pos, move_t* moves)
{
assert(pos->is_check && pos->board[pos->check_square]);
move_t* moves_head = moves;
color_t side = pos->side_to_move, other_side = side^1;
square_t king_sq = pos->pieces[side][0];
square_t check_sq = pos->check_square;
piece_t king = create_piece(side, KING);
piece_t checker = pos->board[check_sq];
// Generate king moves.
// Don't let the king mask its possible destination squares in calls
// to is_square_attacked.
square_t from = king_sq, to = INVALID_SQUARE;
((position_t*)pos)->board[king_sq] = EMPTY;
for (const direction_t* delta = piece_deltas[king]; *delta; ++delta) {
to = from + *delta;
piece_t capture = pos->board[to];
if (capture != EMPTY && !can_capture(king, capture)) continue;
if (is_square_attacked((position_t*)pos,to,other_side)) continue;
((position_t*)pos)->board[king_sq] = king;
moves = add_move(pos, create_move(from, to, king, capture), moves);
((position_t*)pos)->board[king_sq] = EMPTY;
}
((position_t*)pos)->board[king_sq] = king;
// If there are multiple checkers, only king moves are possible.
if (pos->is_check > 1) {
*moves = 0;
return moves-moves_head;
}
// First, the most common case: a check that can be evaded via an
// en passant capture. Note that if we're in check and an en passant
// capture is available, the only way the en passant capture would evade
// the check is if it's the newly moved pawn that's checking us.
direction_t pin_dir;
if (pos->ep_square != EMPTY &&
check_sq+pawn_push[side] == pos->ep_square &&
pos->board[pos->ep_square] == EMPTY) {
piece_t our_pawn = create_piece(side, PAWN);
to = pos->ep_square;
for (int i=0; i<2; ++i) {
from = to-piece_deltas[our_pawn][i];
if (pos->board[from] && pos->board[from] == our_pawn) {
pin_dir = pin_direction(pos, from, king_sq);
if (pin_dir) continue;
moves = add_move(pos,
create_move_enpassant(from, to, our_pawn, checker),
moves);
}
}
}
// Generate captures of the checker.
for (int i = 0; i < pos->num_pawns[side]; ++i) {
from = pos->pawns[side][i];
piece_t piece = create_piece(side, PAWN);
pin_dir = pin_direction(pos, from, king_sq);
if (pin_dir) continue;
if (!possible_attack(from, check_sq, piece)) continue;
if (relative_rank[side][square_rank(from)] == RANK_7) {
// Capture and promote.
for (piece_t promoted=QUEEN; promoted > PAWN; --promoted) {
moves = add_move(pos,
create_move_promote(from, check_sq, piece,
checker, promoted),
moves);
}
} else {
moves = add_move(pos,
create_move(from, check_sq, piece, checker),
moves);
}
}
for (int i = 1; i < pos->num_pieces[side]; ++i) {
from = pos->pieces[side][i];
piece_t piece = pos->board[from];
pin_dir = pin_direction(pos, from, king_sq);
if (pin_dir) continue;
if (!possible_attack(from, check_sq, piece)) continue;
if (piece_slide_type(piece) == NONE) {
moves = add_move(pos,
create_move(from, check_sq, piece, checker),
moves);
} else {
// A sliding piece, keep going until we hit something.
direction_t check_dir = direction(from, check_sq);
for (to=from+check_dir; pos->board[to] == EMPTY; to+=check_dir) {}
if (to == check_sq) {
moves = add_move(pos,
create_move(from, to, piece, checker),
moves);
continue;
}
}
}
if (piece_slide_type(checker) == NONE) {
*moves = 0;
return moves-moves_head;
}
// A slider is doing the checking; generate blocking moves.
direction_t block_dir = direction(check_sq, king_sq);
for (int i = 0; i < pos->num_pawns[side]; ++i) {
from = pos->pawns[side][i];
piece_t piece = create_piece(side, PAWN);
direction_t k_dir;
pin_dir = pin_direction(pos, from, king_sq);
if (pin_dir) continue;
to = from + pawn_push[side];
if (pos->board[to] != EMPTY) continue;
rank_t rank = relative_rank[side][square_rank(from)];
k_dir = direction(to, king_sq);
if (k_dir == block_dir &&
((king_sq < to && check_sq > to) ||
(king_sq > to && check_sq < to))) {
if (rank == RANK_7) {
// Block and promote.
for (piece_t promoted=QUEEN; promoted > PAWN; --promoted) {
moves = add_move(pos,
create_move_promote(from, to, piece, EMPTY, promoted),
moves);
}
} else {
moves = add_move(pos,
create_move(from, to, piece, EMPTY),
moves);
}
}
if (rank != RANK_2) continue;
to += pawn_push[side];
if (pos->board[to]) continue;
k_dir = direction(to, king_sq);
if (k_dir == block_dir &&
((king_sq < to && check_sq > to) ||
(king_sq > to && check_sq < to))) {
moves = add_move(pos,
create_move(from, to, piece, EMPTY),
moves);
}
}
for (int i=1; i<pos->num_pieces[side]; ++i) {
from = pos->pieces[side][i];
piece_t piece = pos->board[from];
direction_t k_dir;
pin_dir = pin_direction(pos, from, king_sq);
if (pin_dir) continue;
if (piece_is_type(piece, KNIGHT)) {
for (const direction_t* delta=piece_deltas[piece];
*delta; ++delta) {
to = from + *delta;
if (pos->board[to] != EMPTY) continue;
k_dir = direction(to, king_sq);
if (k_dir == block_dir &&
((king_sq < to && check_sq > to) ||
(king_sq > to && check_sq < to))) {
moves = add_move(pos,
create_move(from, to, piece, EMPTY),
moves);
}
}
} else {
for (const direction_t* delta=piece_deltas[piece];
*delta; ++delta) {
for (to = from+*delta; pos->board[to] == EMPTY; to+=*delta) {
k_dir = direction(to, king_sq);
if (k_dir == block_dir &&
((king_sq < to && check_sq > to) ||
(king_sq > to && check_sq < to))) {
moves = add_move(pos,
create_move(from, to, piece, EMPTY),
moves);
break;
}
}
}
}
}
*moves = 0;
return moves-moves_head;
}
/*
* Generate pseudo-legal moves which are neither captures nor promotions.
*/
int generate_pseudo_quiet_moves(const position_t* pos, move_t* moves)
{
move_t* moves_head = moves;
color_t side = pos->side_to_move;
piece_t piece;
square_t from;
// Castling. Castles are considered pseudo-legal if we have appropriate
// castling rights, the squares between king and rook are unoccupied,
// and the intermediate square is unattacked. Therefore checking for
// legality just requires seeing if we're in check afterwards.
// This is messy for Chess960, so it's separated into separate cases.
square_t my_king_home = king_home + side*A8;
if (!options.chess960) {
if (has_oo_rights(pos, side) &&
pos->board[my_king_home+1] == EMPTY &&
pos->board[my_king_home+2] == EMPTY &&
!is_square_attacked((position_t*)pos,my_king_home+1,side^1)) {
assert(pos->board[my_king_home] ==
create_piece(pos->side_to_move, KING));
moves = add_move(pos,
create_move_castle(my_king_home, my_king_home+2,
create_piece(side, KING)),
moves);
}
if (has_ooo_rights(pos, side) &&
pos->board[my_king_home-1] == EMPTY &&
pos->board[my_king_home-2] == EMPTY &&
pos->board[my_king_home-3] == EMPTY &&
!is_square_attacked((position_t*)pos,my_king_home-1,side^1)) {
assert(pos->board[my_king_home] ==
create_piece(pos->side_to_move, KING));
moves = add_move(pos,
create_move_castle(my_king_home, my_king_home-2,
create_piece(side, KING)),
moves);
}
} else {
if (has_oo_rights(pos, side)) {
square_t my_f1 = F1 + side*A8;
square_t my_g1 = G1 + side*A8;
square_t my_kr = king_rook_home + side*A8;
bool castle_ok = true;
// Check that rook is unimpeded.
for (square_t sq = MIN(my_kr, my_f1);
sq <= MAX(my_kr, my_f1); ++sq) {
if (sq != my_kr && sq != my_king_home &&
pos->board[sq] != EMPTY) {
castle_ok = false;
break;
}
}
// Check that the king is unimpeded and unattacked
if (castle_ok) {
for (square_t sq = MIN(my_king_home, my_g1);
sq <= my_g1; ++sq) {
if (sq != my_king_home && sq != my_kr &&
pos->board[sq] != EMPTY) {
castle_ok = false;
break;
}
if (sq != my_g1 &&
is_square_attacked((position_t*)pos, sq, side^1)) {
castle_ok = false;
break;
}
}
}
if (castle_ok) moves = add_move(pos,
create_move_castle(my_king_home, my_g1,
create_piece(side, KING)), moves);
}
if (has_ooo_rights(pos, side)) {
square_t my_d1 = D1 + side*A8;
square_t my_c1 = C1 + side*A8;
square_t my_qr = queen_rook_home + side*A8;
bool castle_ok = true;
// Check that rook is unimpeded.
for (square_t sq = MIN(my_qr, my_d1);
sq <= MAX(my_qr, my_d1); ++sq) {
if (sq != my_qr && sq != my_king_home &&
pos->board[sq] != EMPTY) {
castle_ok = false;
break;
}
}
// Check that the king is unimpeded and unattacked
if (castle_ok) {
for (square_t sq = MIN(my_king_home, my_c1);
sq <= MAX(my_king_home, my_c1); ++sq) {
if (sq != my_king_home && sq != my_qr &&
pos->board[sq] != EMPTY) {
castle_ok = false;
break;
}
if (sq != my_c1 &&
is_square_attacked((position_t*)pos, sq, side^1)) {
castle_ok = false;
break;
}
}
}
if (castle_ok) moves = add_move(pos,
create_move_castle(my_king_home, my_c1,
create_piece(side, KING)),
moves);
}
}
for (int i = 0; i < pos->num_pieces[side]; ++i) {
from = pos->pieces[side][i];
piece = pos->board[from];
assert(piece_color(piece) == side && piece_type(piece) != PAWN);
generate_piece_noncaptures(pos, from, piece, &moves);
}
piece = create_piece(side, PAWN);
for (int i=0; i<pos->num_pawns[side]; ++i) {
from = pos->pawns[side][i];
assert(pos->board[from] == piece);
generate_pawn_quiet_moves(pos, from, piece, &moves);
}
*moves = 0;
return (moves-moves_head);
}