function reachable_squares()
{
#Array of square where the piece can move to
$squares = array();
$csq = $this->get_current_square();
$hdist = abs(Board::horz_distance("a1", $csq));
$vdist = abs(Board::vert_distance("a1", $csq));
$dist = $hdist > $vdist ? $vdist : $hdist;
$sq = Board::add_horz_distance($csq, -$dist);
$sq = Board::add_vert_distance($sq, -$dist);
$squares = array_merge($squares, Board::squares_in_line($csq, $sq));
$hdist = abs(Board::horz_distance("h1", $csq));
$vdist = abs(Board::vert_distance("h1", $csq));
$dist = $hdist > $vdist ? $vdist : $hdist;
$sq = Board::add_horz_distance($csq, $dist);
$sq = Board::add_vert_distance($sq, -$dist);
$squares = array_merge($squares, Board::squares_in_line($csq, $sq));
$hdist = abs(Board::horz_distance("a8", $csq));
$vdist = abs(Board::vert_distance("a8", $csq));
$dist = $hdist > $vdist ? $vdist : $hdist;
$sq = Board::add_horz_distance($csq, -$dist);
$sq = Board::add_vert_distance($sq, $dist);
$squares = array_merge($squares, Board::squares_in_line($csq, $sq));
$hdist = abs(Board::horz_distance("h8", $csq));
$vdist = abs(Board::vert_distance("h8", $csq));
$dist = $hdist > $vdist ? $vdist : $hdist;
$sq = Board::add_horz_distance($csq, $dist);
$sq = Board::add_vert_distance($sq, $dist);
$squares = array_merge($squares, Board::squares_in_line($csq, $sq));
#Removes current position square
$squares = preg_grep("/^{$csq}\$/", $squares, PREG_GREP_INVERT);
return $squares;
}
function reachable_squares()
{
#Array of square where the piece can move to
$squares = array();
$csq = $this->get_current_square();
$x = Board::horz_distance("a4", $csq);
$y = Board::vert_distance("d1", $csq);
$row_start = 'a' . ($y + 1);
$row_end = 'h' . ($y + 1);
$col_start = chr(ord('a') + $x) . '1';
$col_end = chr(ord('a') + $x) . '8';
$row = Board::squares_in_line($row_start, $row_end);
$col = Board::squares_in_line($col_start, $col_end);
$squares = array_merge($squares, $row, $col);
#Removes current position square
$squares = preg_grep("/^{$csq}\$/", $squares, PREG_GREP_INVERT);
return $squares;
}
/**
* Takes two parameters containing the name of the square to move from and
* the name of the square to move to. They should be validated with
* "square_is_valid()" in Board before calling. Optionally takes a
* third parameter, which can be set to zero to indicate that no legality
* checking should be done. In this case, flags indicating 'en passant' pawn
* captures or castling will not be set! Only by entirely validating the move
* do these flags have any meaning. The default is to validate every move.
*
* @param string $sq1 current position of the piece
* @param string $sq2 destination of the piece
* @param bool $validate whether to validate the move
*
* @return MoveListEntry|NULL a MoveListEntry representing the move just made or NULL
* if any errors occur and the move was not considered
*/
public function make_move($sq1, $sq2, $validate = true)
{
$move = NULL;
#Invalid square
if (Board::square_is_valid($sq1) == false) {
return NULL;
}
if (Board::square_is_valid($sq2) == false) {
return NULL;
}
if ($validate) {
if ($this->is_move_legal($sq1, $sq2) == false) {
return NULL;
}
}
$player1 = $this->players[0];
$player2 = $this->players[1];
$board = $this->board;
$piece = $board->get_piece_at($sq1);
$player = $piece->get_player();
#if no piece at sq1
if ($piece == NULL) {
return NULL;
}
$movelist = $this->movelist;
$capture = $board->get_piece_at($sq2);
$flags = 0x0;
if ($validate && $piece instanceof Pawn) {
if ($player == $player1) {
if (Board::vert_distance("d8", $sq2) == 0) {
$flags = $flags | self::__MOVE_PROMOTE__;
}
//Bitwise Or
} else {
if (Board::vert_distance("d1", $sq2) == 0) {
$flags = $flags | self::__MOVE_PROMOTE__;
}
//Bitwise Or
}
}
if ($capture) {
$flags = $flags | self::__MOVE_CAPTURE__;
//Bitwise Or
$capture->set_captured(1);
$board->set_piece_at($sq1, NULL);
$board->set_piece_at($sq2, $piece);
$piece->set_current_square($sq2);
$piece->set_moved(1);
$move = $movelist->add_move($piece, $sq1, $sq2, $flags);
$movenum = $move->get_move_num();
$this->captures[$player][$movenum] = $capture;
} else {
if ($validate && $piece instanceof Pawn && $this->_is_valid_en_passant($piece, $sq1, $sq2)) {
$last_moved = $movelist->get_last_moved();
$move = $movelist->get_move($movelist->get_move_num(), $last_moved);
$capture = $move->get_piece();
$flags = $flags | self::__MOVE_CAPTURE__;
$flags = $flags | self::__MOVE_EN_PASSANT__;
$capture->set_captured(1);
$board->set_piece_at($sq1, NULL);
$board->set_piece_at($sq2, $piece);
$piece->set_current_square($sq2);
$move = $movelist->add_move($piece, $sq1, $sq2, $flags);
$this->analyzed = 0;
$movenum = $move->get_move_num();
$piece->_set_firstmoved($movenum);
$this->captures[$player][$movenum] = $capture;
} else {
if ($validate && $piece instanceof King) {
if ($this->_is_valid_short_castle($piece, $sq1, $sq2)) {
$flags = $flags | self::__MOVE_CASTLE_SHORT__;
}
if ($this->_is_valid_long_castle($piece, $sq1, $sq2)) {
$flags = $flags | self::__MOVE_CASTLE_LONG__;
}
}
if ($flags & self::__MOVE_CASTLE_SHORT__ || $flags & self::__MOVE_CASTLE_LONG__) {
$rook_sq = $king_sq = $rook_sq_new = $king_sq_new = NULL;
$rook = $king = NULL;
if ($player == $player1) {
$rook_sq = $flags & self::__MOVE_CASTLE_SHORT__ ? "h1" : "a1";
$rook_sq_new = $flags & self::__MOVE_CASTLE_SHORT__ ? "f1" : "d1";
$king_sq = "e1";
$king_sq_new = $flags & self::__MOVE_CASTLE_SHORT__ ? "g1" : "c1";
} else {
$rook_sq = $flags & self::__MOVE_CASTLE_SHORT__ ? "h8" : "a8";
$rook_sq_new = $flags & self::__MOVE_CASTLE_SHORT__ ? "f8" : "d8";
$king_sq = "e8";
$king_sq_new = $flags & self::__MOVE_CASTLE_SHORT__ ? "g8" : "c8";
}
$king = $board->get_piece_at($king_sq);
$rook = $board->get_piece_at($rook_sq);
$board->set_piece_at($king_sq, NULL);
$board->set_piece_at($king_sq_new, $king);
$king->set_current_square($king_sq_new);
$king->set_moved(1);
$board->set_piece_at($rook_sq, NULL);
$board->set_piece_at($rook_sq_new, $rook);
$rook->set_current_square($rook_sq_new);
$rook->set_moved(1);
$move = $movelist->add_move($piece, $sq1, $sq2, $flags);
$movenum = $move->get_move_num();
$this->analyzed = 0;
$king->_set_firstmoved($movenum);
$rook->_set_firstmoved($movenum);
} else {
$board->set_piece_at($sq1, NULL);
$board->set_piece_at($sq2, $piece);
$piece->set_current_square($sq2);
$piece->set_moved(1);
$move = $movelist->add_move($piece, $sq1, $sq2, $flags);
$movenum = $move->get_move_num();
$piece->_set_firstmoved($movenum);
}
}
}
return $move;
}