3 # There are too many chess modules on CPAN already, so here's another one...
13 # Takes in a FICS style 12-type position.
15 my ($class, $str) = @_;
17 my (@x) = split / /, $str;
19 $pos->{'board'} = Board->new(@x[1..8]);
20 $pos->{'toplay'} = $x[9];
21 $pos->{'ep_file_num'} = $x[10];
22 $pos->{'white_castle_k'} = $x[11];
23 $pos->{'white_castle_q'} = $x[12];
24 $pos->{'black_castle_k'} = $x[13];
25 $pos->{'black_castle_q'} = $x[14];
26 $pos->{'time_since_100move_rule_reset'} = $x[15];
27 $pos->{'player_w'} = $x[17];
28 $pos->{'player_b'} = $x[18];
29 $pos->{'player_w'} =~ s/^W?[FCIG]M//;
30 $pos->{'player_b'} =~ s/^W?[FCIG]M//;
31 $pos->{'move_num'} = $x[26];
32 $pos->{'last_move'} = $x[29];
39 my ($class, $white, $black) = @_;
40 $white = "base64:" . MIME::Base64::encode_base64($white);
41 $black = "base64:" . MIME::Base64::encode_base64($black);
42 return $class->new("<12> rnbqkbnr pppppppp -------- -------- -------- -------- PPPPPPPP RNBQKBNR W -1 1 1 1 1 0 dummygamenum $white $black -2 dummytime dummyincrement 39 39 dummytime dummytime 1 none (0:00) none 0 0 0");
49 my $fen = $pos->{'board'}->fen();
53 $fen .= lc($pos->{'toplay'});
57 $castling .= "K" if ($pos->{'white_castle_k'} == 1);
58 $castling .= "Q" if ($pos->{'white_castle_q'} == 1);
59 $castling .= "k" if ($pos->{'black_castle_k'} == 1);
60 $castling .= "q" if ($pos->{'black_castle_q'} == 1);
61 $castling = "-" if ($castling eq "");
62 # $castling = "-"; # chess960
68 if ($pos->{'ep_file_num'} != -1) {
69 my $col = $pos->{'ep_file_num'};
70 my $nep = (qw(a b c d e f g h))[$col];
72 if ($pos->{'toplay'} eq 'B') {
79 # Showing the en passant square when actually no capture can be made
80 # seems to confuse at least Rybka. Thus, check if there's actually
81 # a pawn of the opposite side that can do the en passant move, and if
82 # not, just lie -- it doesn't matter anyway. I'm unsure what's the
83 # "right" thing as per the standard, though.
85 if ($pos->{'toplay'} eq 'B') {
86 $ep = $nep if ($col > 0 && $pos->{'board'}[4][$col-1] eq 'p');
87 $ep = $nep if ($col < 7 && $pos->{'board'}[4][$col+1] eq 'p');
89 $ep = $nep if ($col > 0 && $pos->{'board'}[3][$col-1] eq 'P');
90 $ep = $nep if ($col < 7 && $pos->{'board'}[3][$col+1] eq 'P');
98 $fen .= $pos->{'time_since_100move_rule_reset'};
102 $fen .= $pos->{'move_num'};
109 my $json = { %$pos, board => undef, fen => $pos->fen() };
110 if ($json->{'player_w'} =~ /^base64:(.*)$/) {
111 $json->{'player_w'} = MIME::Base64::decode_base64($1);
113 if ($json->{'player_b'} =~ /^base64:(.*)$/) {
114 $json->{'player_b'} = MIME::Base64::decode_base64($1);
119 sub parse_pretty_move {
120 my ($pos, $move) = @_;
121 return $pos->{'board'}->parse_pretty_move($move, $pos->{'toplay'});
124 # Returns a new Position object.
126 my ($pos, $from_row, $from_col, $to_row, $to_col, $promo) = @_;
128 my $from_square = _pos_to_square($from_row, $from_col);
129 my $to_square = _pos_to_square($to_row, $to_col);
132 $np->{'board'} = $pos->{'board'}->make_move($from_row, $from_col, $to_row, $to_col, $promo);
133 if ($pos->{'toplay'} eq 'W') {
134 $np->{'toplay'} = 'B';
135 $np->{'move_num'} = $pos->{'move_num'};
137 $np->{'toplay'} = 'W';
138 $np->{'move_num'} = $pos->{'move_num'} + 1;
141 my $piece = $pos->{'board'}[$from_row][$from_col];
142 my $dest_piece = $pos->{'board'}[$to_row][$to_col];
144 # Find out if this was a two-step pawn move.
145 if (lc($piece) eq 'p' && abs($from_row - $to_row) == 2) {
146 $np->{'ep_file_num'} = $from_col;
148 $np->{'ep_file_num'} = -1;
152 $np->{'white_castle_k'} = $pos->{'white_castle_k'};
153 $np->{'white_castle_q'} = $pos->{'white_castle_q'};
154 $np->{'black_castle_k'} = $pos->{'black_castle_k'};
155 $np->{'black_castle_q'} = $pos->{'black_castle_q'};
157 $np->{'white_castle_k'} = 0;
158 $np->{'white_castle_q'} = 0;
159 } elsif ($piece eq 'k') {
160 $np->{'black_castle_k'} = 0;
161 $np->{'black_castle_q'} = 0;
162 } elsif ($from_square eq 'a1' || $to_square eq 'a1') {
163 $np->{'white_castle_q'} = 0;
164 } elsif ($from_square eq 'h1' || $to_square eq 'h1') {
165 $np->{'white_castle_k'} = 0;
166 } elsif ($from_square eq 'a8' || $to_square eq 'a8') {
167 $np->{'black_castle_q'} = 0;
168 } elsif ($from_square eq 'h8' || $to_square eq 'h8') {
169 $np->{'black_castle_k'} = 0;
173 if (lc($piece) eq 'p' || $dest_piece ne '-') {
174 $np->{'time_since_100move_rule_reset'} = 0;
176 $np->{'time_since_100move_rule_reset'} = $pos->{'time_since_100move_rule_reset'} + 1;
178 $np->{'player_w'} = $pos->{'player_w'};
179 $np->{'player_b'} = $pos->{'player_b'};
180 my ($move, $nb) = $pos->{'board'}->prettyprint_move($from_row, $from_col, $to_row, $to_col, $promo);
181 $np->{'last_move'} = $move;
186 my ($row, $col) = @_;
187 return sprintf("%c%d", ord('a') + $col, 8 - $row);
194 for my $pv_move (@pv) {
195 my ($from_row, $from_col, $to_row, $to_col, $promo) = _parse_uci_move($pv_move);
196 $pvpos = $pvpos->make_move($from_row, $from_col, $to_row, $to_col, $promo);
202 sub _col_letter_to_num {
203 return ord(shift) - ord('a');
206 sub _row_letter_to_num {
207 return 7 - (ord(shift) - ord('1'));
210 sub _parse_uci_move {
212 my $from_col = _col_letter_to_num(substr($move, 0, 1));
213 my $from_row = _row_letter_to_num(substr($move, 1, 1));
214 my $to_col = _col_letter_to_num(substr($move, 2, 1));
215 my $to_row = _row_letter_to_num(substr($move, 3, 1));
216 my $promo = substr($move, 4, 1);
217 return ($from_row, $from_col, $to_row, $to_col, $promo);