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Revision: 1.9
Committed: Wed Jun 25 20:11:33 2008 UTC (15 years, 10 months ago) by root
Branch: MAIN
Changes since 1.8: +38 -42 lines
Log Message:
completely rewrote mvoe logic

File Contents

# Content
1 package Games::Go::SimpleBoard;
2
3 =head1 NAME
4
5 Games::Go::SimpleBoard - represent a simple go board
6
7 =head1 SYNOPSIS
8
9 use Games::Go::SimpleBoard;
10
11 =head1 DESCRIPTION
12
13 Please supply a description )
14
15 =head2 EXPORTED CONSTANTS
16
17 Marker types for each board position (ORed together):
18
19 MARK_TRIANGLE # triangle mark
20 MARK_SQUARE # square mark
21 MARK_CIRCLE # circle mark
22 MARK_CROSS # cross mark
23 MARK_SMALL_B # small stone, used for scoring or marking
24 MARK_SMALL_W # small stone, used for scoring or marking
25 MARK_B # normal black stone
26 MARK_W # normal whit stone
27 MARK_GRAYED # in conjunction with MARK_[BW], grays the stone
28 MARK_LABEL # a text label
29 MARK_HOSHI # this is a hoshi point (not used much)
30 MARK_MOVE # this is a regular move
31 MARK_KO # this is a ko position
32 MARK_REDRAW # ignored, can be used for your own purposes
33
34 COLOUR_WHITE # guarenteed to be 0
35 COLOUR_BLACK # guarenteed to be 1
36
37 MOVE_HANDICAP # used as "x-coordinate" for handicap moves
38 MOVE_PASS # can be used as "x-coordinate" for pass moves
39
40 =head2 METHODS
41
42 =over 4
43
44 =cut
45
46 no warnings;
47 use strict;
48
49 use Carp ();
50
51 use base Exporter::;
52
53 our $VERSION = '1.0';
54
55 our @EXPORT = qw(
56 MARK_TRIANGLE MARK_SQUARE MARK_CIRCLE MARK_SMALL_B MARK_SMALL_W MARK_B
57 MARK_W MARK_GRAYED MARK_MOVE MARK_LABEL MARK_HOSHI MARK_KO MARK_CROSS
58 MARK_REDRAW
59 COLOUR_BLACK COLOUR_WHITE
60 MOVE_HANDICAP MOVE_PASS
61 );
62
63 # marker types for each board position (ORed together)
64
65 sub MARK_TRIANGLE (){ 0x0001 }
66 sub MARK_SQUARE (){ 0x0002 }
67 sub MARK_CIRCLE (){ 0x0004 }
68 sub MARK_SMALL_B (){ 0x0008 } # small stone, used for scoring or marking
69 sub MARK_SMALL_W (){ 0x0010 } # small stone, used for scoring or marking
70 sub MARK_B (){ 0x0020 } # normal black stone
71 sub MARK_W (){ 0x0040 } # normal whit stone
72 sub MARK_GRAYED (){ 0x0080 } # in conjunction with MARK_[BW], grays the stone
73 sub MARK_LABEL (){ 0x0100 }
74 sub MARK_HOSHI (){ 0x0200 } # this is a hoshi point (not used much)
75 sub MARK_MOVE (){ 0x0400 } # this is a regular move
76 sub MARK_KO (){ 0x0800 } # this is a ko position
77 sub MARK_CROSS (){ 0x1000 }
78 sub MARK_REDRAW (){ 0x8000 }
79
80 sub COLOUR_WHITE (){ 0 }
81 sub COLOUR_BLACK (){ 1 }
82
83 sub MOVE_PASS (){ undef }
84 sub MOVE_HANDICAP (){ -2 }
85
86 =item my $board = new $size
87
88 Creates a new empty board of the given size.
89
90 C<< $board->{size} >> stores the board size.
91
92 C<< $board->{max} >> stores the maximum board coordinate (size-1).
93
94 C<< $board->{captures}[COLOUR_xxx] >> stores the number of captured stones for
95 the given colour.
96
97 C<< $board->{board} >> stores a two-dimensional array with board contents.
98
99 =cut
100
101 sub new {
102 my $class = shift;
103 my $size = shift;
104
105 bless {
106 max => $size - 1,
107 size => $size,
108 board => [map [(0) x $size], 1 .. $size],
109 captures => [0, 0], # captures
110 #timer => [],
111 #score => [],
112 @_,
113 unmark => [],
114 }, $class
115 }
116
117 # inefficient and primitive, I hear you say?
118 # well... you are right :)
119 # use an extremely dumb floodfill algorithm to get rid of captured stones
120 sub capture {
121 my ($self, $mark, $x, $y) = @_;
122
123 my %seen;
124 my @found;
125 my @nodes = ([$x,$y]);
126 my $board = $self->{board};
127
128 my $max = $self->{max};
129
130 while (@nodes) {
131 my ($x, $y) = @{pop @nodes};
132 unless ($seen{$x,$y}++) {
133 if ($board->[$x][$y] & $mark) {
134 push @found, [$x, $y];
135
136 push @nodes, [$x-1, $y] unless $seen{$x-1, $y} || $x <= 0;
137 push @nodes, [$x+1, $y] unless $seen{$x+1, $y} || $x >= $max;
138 push @nodes, [$x, $y-1] unless $seen{$x, $y-1} || $y <= 0;
139 push @nodes, [$x, $y+1] unless $seen{$x, $y+1} || $y >= $max;
140 } elsif (!($board->[$x][$y] & (MARK_B | MARK_W))) {
141 return;
142 }
143 }
144 }
145
146 @found
147 }
148
149 =item $hint = $board->update ([update-structures...])
150
151 Each update-structure itself is also an array-ref:
152
153 [$x, $y, $clr, $set, $label, $hint] # update or move
154 [MOVE_HANDICAP, $handicap] # black move, setup handicap
155 [MOVE_PASS] # pass
156 [] # also pass (deprecated!)
157
158 It changes the board or executes a move, by first clearing the bits
159 specified in C<$clr>, then setting bits specified in C<$set>.
160
161 If C<$set> includes C<MARK_LABEL>, the label text must be given in
162 C<$label>.
163
164 If C<$set> contains C<MARK_MOVE> then surrounded stones will be removed
165 from the board and (simple) Kos are detected and marked with square
166 symbols and C<MARK_KO>, after removing other marking symbols. The
167 markings are also removed with the next next update structure that uses
168 C<MARK_MOVE>, so this flag is suited well for marking, well, moves. Note
169 that you can make invalid "moves" (such as suicide) and C<update> will
170 try to cope with it. You can use C<is_valid_move> to avoid making illegal
171 moves.
172
173 For handicap "moves", currently only board sizes 9, 13 and 19 are
174 supported and only handicap values from 2 to 9. The placement follows the
175 IGS rules, if you want other placements, you have to set it up yourself.
176
177 This function modifies the C<$hint> member of the specified structure
178 to speed up repeated board generation and updates with the same update
179 structures.
180
181 If the hint member is a reference the scalar pointed to by the reference
182 is updated instead.
183
184 If all this hint member thing is confusing, just ignore it and specify
185 it as C<undef> or leave it out of the array entirely. Do make sure that
186 you keep your update structures around as long as previous updates don't
187 change, however, as regenerating a full board position from hinted
188 update structures is I<much> faster then recreating it from fresh update
189 structures.
190
191 Example, make two silly moves:
192
193 $board->update ([[0, 18, -1, MARK_B | MARK_MOVE],
194 [0, 17, -1, MARK_W | MARK_MOVE]]);
195
196 =cut
197
198 our %HANDICAP_COORD = (
199 9 => [2, 4, 6],
200 13 => [3, 6, 9],
201 19 => [3, 9, 15],
202 );
203 our %HANDICAP_XY = (
204 2 => [qw(0,2 2,0 )],
205 3 => [qw(0,2 2,0 0,0 )],
206 4 => [qw(0,2 2,0 0,0 2,2 )],
207 5 => [qw(0,2 2,0 0,0 2,2 1,1)],
208 6 => [qw(0,2 2,0 0,0 2,2 0,1 2,1 )],
209 7 => [qw(0,2 2,0 0,0 2,2 0,1 2,1 1,1)],
210 8 => [qw(0,2 2,0 0,0 2,2 0,1 2,1 1,0 1,2 )],
211 9 => [qw(0,2 2,0 0,0 2,2 0,1 2,1 1,0 1,2 1,1)],
212 );
213
214 our $mark_symbols = MARK_CIRCLE | MARK_SQUARE | MARK_TRIANGLE | MARK_CROSS | MARK_KO;
215
216 sub update {
217 my ($self, $path) = @_;
218
219 my $board = $self->{board};
220
221 for (@$path) {
222 my ($x, $y, $clr, $set, $label) = @$_;
223
224 if (!defined $x) {
225 # pass
226
227 } elsif ($x == MOVE_HANDICAP) {
228 # $y = #handicap stones
229 my $c = $HANDICAP_COORD{$self->{size}}
230 or Carp::croak "$self->{size}: illegal board size for handicap";
231 my $h = $HANDICAP_XY{$y}
232 or Carp::croak "$y: illegal number of handicap stones";
233
234 for (@$h) {
235 my ($x, $y) = map $c->[$_], split /,/;
236 $board->[$x][$y] = MARK_B | MARK_MOVE;
237 }
238
239 } else {
240 my $space = \$board->[$x][$y];
241
242 $$space = $$space & ~$clr | $set;
243
244 $self->{label}[$x][$y] = $label if $set & MARK_LABEL;
245
246 if ($set & MARK_MOVE) {
247 $$_ &= ~$mark_symbols for @{ $self->{unmark} };
248 @{ $self->{unmark} } = $space;
249
250 unless (${ $_->[5] ||= \my $hint }) {
251 my ($own, $opp) =
252 $set & MARK_B
253 ? (MARK_B, MARK_W)
254 : (MARK_W, MARK_B);
255
256 my (@capture, $suicide);
257
258 push @capture, $self->capture ($opp, $x-1, $y) if $x > 0 && $board->[$x-1][$y] & $opp;
259 push @capture, $self->capture ($opp, $x+1, $y) if $x < $self->{max} && $board->[$x+1][$y] & $opp;
260 push @capture, $self->capture ($opp, $x, $y-1) if $y > 0 && $board->[$x][$y-1] & $opp;
261 push @capture, $self->capture ($opp, $x, $y+1) if $y < $self->{max} && $board->[$x][$y+1] & $opp;
262
263 # keep only unique coordinates
264 @capture = do { my %seen; grep !$seen{"$_->[0],$_->[1]"}++, @capture };
265
266 # remove captured stones
267 $self->{captures}[$own == MARK_B ? COLOUR_BLACK : COLOUR_WHITE] += @capture;
268 $self->{board}[$_->[0]][$_->[1]] = 0
269 for @capture;
270
271 $suicide += $self->capture ($own, $x, $y);
272
273 ${ $_->[5] } ||= !(@capture || $suicide);
274
275 if (!$suicide && @capture == 1) {
276 # possible ko. now check liberties on placed stone
277
278 my $libs;
279
280 $libs++ if $x > 0 && !($board->[$x-1][$y] & $opp);
281 $libs++ if $x < $self->{max} && !($board->[$x+1][$y] & $opp);
282 $libs++ if $y > 0 && !($board->[$x][$y-1] & $opp);
283 $libs++ if $y < $self->{max} && !($board->[$x][$y+1] & $opp);
284
285 if ($libs == 1) {
286 $$space = $$space & ~$mark_symbols | MARK_KO;
287
288 ($x, $y) = @{$capture[0]};
289 $board->[$x][$y] |= MARK_KO;
290
291 push @{ $self->{unmark} }, \$board->[$x][$y];
292 }
293 }
294 }
295 }
296 }
297 }
298 }
299
300 =item $board->is_valid_move ($colour, $x, $y[, $may_suicide])
301
302 Returns true if the move of the given colour on the given coordinates is
303 valid or not. Kos are taken into account as long as they are marked with
304 C<MARK_KO>. Suicides are invalid unless C<$may_suicide> is true (e.g. for
305 new zealand rules)
306
307 =cut
308
309 sub is_valid_move {
310 my ($self, $colour, $x, $y, $may_suicide) = @_;
311
312 my $board = $self->{board};
313
314 return if $board->[$x][$y] & (MARK_B | MARK_W | MARK_KO);
315
316 if ($may_suicide) {
317 return 1;
318 } else {
319 my ($own, $opp) = $colour == COLOUR_BLACK
320 ? (MARK_B, MARK_W)
321 : (MARK_W, MARK_B);
322
323 # try the move
324 local $board->[$x][$y] = $board->[$x][$y] | $own;
325
326 return 1 if $x > 0 && $board->[$x-1][$y] & $opp && $self->capture ($opp, $x-1, $y, 1);
327 return 1 if $x < $self->{max} && $board->[$x+1][$y] & $opp && $self->capture ($opp, $x+1, $y, 1);
328 return 1 if $y > 0 && $board->[$x][$y-1] & $opp && $self->capture ($opp, $x, $y-1, 1);
329 return 1 if $y < $self->{max} && $board->[$x][$y+1] & $opp && $self->capture ($opp, $x, $y+1, 1);
330
331 return !$self->capture ($own, $x, $y, 1);
332 }
333 }
334
335 1;
336
337 =back
338
339 =head2 AUTHOR
340
341 Marc Lehmann <schmorp@schmorp.de>
342
343 =head2 SEE ALSO
344
345 L<Gtk2::GoBoard>.
346
347 =cut
348