| 1 | /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\ |
| 2 | * This is GNU Go, a Go program. Contact gnugo@gnu.org, or see * |
| 3 | * http://www.gnu.org/software/gnugo/ for more information. * |
| 4 | * * |
| 5 | * Copyright 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, * |
| 6 | * 2008 and 2009 by the Free Software Foundation. * |
| 7 | * * |
| 8 | * This program is free software; you can redistribute it and/or * |
| 9 | * modify it under the terms of the GNU General Public License as * |
| 10 | * published by the Free Software Foundation - version 3 or * |
| 11 | * (at your option) any later version. * |
| 12 | * * |
| 13 | * This program is distributed in the hope that it will be useful, * |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of * |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * |
| 16 | * GNU General Public License in file COPYING for more details. * |
| 17 | * * |
| 18 | * You should have received a copy of the GNU General Public * |
| 19 | * License along with this program; if not, write to the Free * |
| 20 | * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, * |
| 21 | * Boston, MA 02111, USA. * |
| 22 | \* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ |
| 23 | |
| 24 | #include <stdio.h> |
| 25 | #include "liberty.h" |
| 26 | #include "patterns.h" |
| 27 | |
| 28 | |
| 29 | /* Test whether apos and bpos can be cut. If yes, return 1 and |
| 30 | * store it in the cut list of dragons.c. |
| 31 | */ |
| 32 | int |
| 33 | disconnect_helper(int apos, int bpos) |
| 34 | { |
| 35 | int color = board[apos]; |
| 36 | int move; |
| 37 | ASSERT1(color == board[bpos] && IS_STONE(color), apos); |
| 38 | |
| 39 | if (disconnect(apos, bpos, &move)) { |
| 40 | add_cut(apos, bpos, move); |
| 41 | return 1; |
| 42 | } |
| 43 | return 0; |
| 44 | } |
| 45 | |
| 46 | /* Try to match all (permutations of) connection patterns at (m,n). |
| 47 | * For each match, if it is a B pattern, set cutting point in |
| 48 | * cutting_points array. If it is a C pattern, amalgamate the dragons |
| 49 | * in the pattern. |
| 50 | */ |
| 51 | |
| 52 | static void |
| 53 | cut_connect_callback(int anchor, int color, struct pattern *pattern, |
| 54 | int ll, void *data) |
| 55 | { |
| 56 | int move; |
| 57 | int k; |
| 58 | int first_dragon = NO_MOVE; |
| 59 | int second_dragon = NO_MOVE; |
| 60 | |
| 61 | int other = OTHER_COLOR(color); |
| 62 | UNUSED(data); |
| 63 | |
| 64 | move = AFFINE_TRANSFORM(pattern->move_offset, ll, anchor); |
| 65 | |
| 66 | if ((pattern->class & CLASS_B) && !safe_move(move, other)) |
| 67 | return; |
| 68 | |
| 69 | if (pattern->class & CLASS_C) { |
| 70 | /* If C pattern, test if there are more than one dragon in this |
| 71 | * pattern so that there is something to connect, before doing any |
| 72 | * expensive reading. |
| 73 | */ |
| 74 | |
| 75 | for (k = 0; k < pattern->patlen; ++k) { /* match each point */ |
| 76 | /* transform pattern real coordinate */ |
| 77 | int pos = AFFINE_TRANSFORM(pattern->patn[k].offset, ll, anchor); |
| 78 | |
| 79 | /* Look for distinct dragons. */ |
| 80 | if (pattern->patn[k].att == ATT_O) { |
| 81 | if (first_dragon == NO_MOVE) |
| 82 | first_dragon = dragon[pos].origin; |
| 83 | else if (second_dragon == NO_MOVE |
| 84 | && dragon[pos].origin != first_dragon) { |
| 85 | second_dragon = dragon[pos].origin; |
| 86 | /* A second dragon found, no need to continue looping. */ |
| 87 | break; |
| 88 | } |
| 89 | } |
| 90 | } |
| 91 | if (second_dragon == NO_MOVE) |
| 92 | return; /* Nothing to amalgamate. */ |
| 93 | } |
| 94 | |
| 95 | /* If the pattern has a constraint, call the autohelper to see |
| 96 | * if the pattern must be rejected. |
| 97 | */ |
| 98 | if (pattern->autohelper_flag & HAVE_CONSTRAINT) { |
| 99 | if (!pattern->autohelper(ll, move, color, 0)) |
| 100 | return; |
| 101 | } |
| 102 | |
| 103 | /* If the pattern has a helper, call it to see if the pattern must |
| 104 | * be rejected. |
| 105 | */ |
| 106 | if (pattern->helper) { |
| 107 | if (!pattern->helper(pattern, ll, move, color)) |
| 108 | return; |
| 109 | } |
| 110 | |
| 111 | if ((pattern->class & CLASS_B) |
| 112 | && !(pattern->class & CLASS_s)) { |
| 113 | /* Require that the X stones in the pattern are tactically safe. */ |
| 114 | for (k = 0; k < pattern->patlen; ++k) { /* match each point */ |
| 115 | if (pattern->patn[k].att == ATT_X) { |
| 116 | /* transform pattern real coordinate */ |
| 117 | int pos = AFFINE_TRANSFORM(pattern->patn[k].offset, ll, anchor); |
| 118 | |
| 119 | if (attack(pos, NULL) == WIN |
| 120 | && (move == NO_MOVE |
| 121 | || !does_defend(move, pos))) |
| 122 | return; /* Match failed */ |
| 123 | } |
| 124 | } |
| 125 | } |
| 126 | |
| 127 | /* Get here => Pattern matches. */ |
| 128 | if (pattern->class & CLASS_B) { |
| 129 | DEBUG(DEBUG_DRAGONS, "Cutting pattern %s+%d found at %1m\n", |
| 130 | pattern->name, ll, anchor); |
| 131 | DEBUG(DEBUG_DRAGONS, "cutting point %1m\n", move); |
| 132 | } |
| 133 | else if (pattern->class & CLASS_C) |
| 134 | DEBUG(DEBUG_DRAGONS, "Connecting pattern %s+%d found at %1m\n", |
| 135 | pattern->name, ll, anchor); |
| 136 | |
| 137 | /* does the pattern have an action? */ |
| 138 | if (pattern->autohelper_flag & HAVE_ACTION) { |
| 139 | pattern->autohelper(ll, move, color, 1); |
| 140 | } |
| 141 | |
| 142 | /* If it is a B pattern, set cutting point. */ |
| 143 | |
| 144 | if (pattern->class & CLASS_B) { |
| 145 | cutting_points[move] |= color; |
| 146 | } |
| 147 | else if (!(pattern->class & CLASS_C)) |
| 148 | return; /* Nothing more to do, up to the helper or autohelper |
| 149 | to amalgamate dragons or modify eye space. */ |
| 150 | |
| 151 | /* If it is a C pattern, find the dragons to connect. |
| 152 | * If it is a B pattern, find eye space points to inhibit connection |
| 153 | * through. |
| 154 | */ |
| 155 | first_dragon = NO_MOVE; |
| 156 | second_dragon = NO_MOVE; |
| 157 | for (k = 0; k < pattern->patlen; ++k) { /* match each point */ |
| 158 | /* transform pattern real coordinate */ |
| 159 | int pos = AFFINE_TRANSFORM(pattern->patn[k].offset, ll, anchor); |
| 160 | |
| 161 | /* Look for dragons to amalgamate. Never amalgamate stones which |
| 162 | * can be attacked. |
| 163 | */ |
| 164 | if ((pattern->class & CLASS_C) |
| 165 | && board[pos] == color |
| 166 | && pattern->patn[k].att == ATT_O |
| 167 | && ((pattern->class & CLASS_s) || attack(pos, NULL) == 0)) { |
| 168 | if (first_dragon == NO_MOVE) |
| 169 | first_dragon = dragon[pos].origin; |
| 170 | else if (second_dragon == NO_MOVE |
| 171 | && dragon[pos].origin != first_dragon) { |
| 172 | second_dragon = dragon[pos].origin; |
| 173 | /* A second dragon found, we amalgamate them at once. */ |
| 174 | /* Want this output if verbose or DEBUG_DRAGONS is on. */ |
| 175 | if (verbose || (debug & DEBUG_DRAGONS)) |
| 176 | gprintf("Pattern %s joins %C dragons %1m, %1m\n", |
| 177 | pattern->name, color, first_dragon, second_dragon); |
| 178 | join_dragons(second_dragon, first_dragon); |
| 179 | /* Now look for another second dragon. */ |
| 180 | second_dragon = NO_MOVE; |
| 181 | first_dragon = dragon[pos].origin; |
| 182 | } |
| 183 | } |
| 184 | |
| 185 | /* Inhibit connections */ |
| 186 | if (pattern->class & CLASS_B) { |
| 187 | if (pattern->patn[k].att != ATT_not) |
| 188 | break; /* The inhibition points are guaranteed to come first. */ |
| 189 | cutting_points[pos] |= color; |
| 190 | DEBUG(DEBUG_DRAGONS, "inhibiting connection at %1m\n", pos); |
| 191 | } |
| 192 | } /* loop over elements */ |
| 193 | } |
| 194 | |
| 195 | |
| 196 | /* Only consider B patterns. */ |
| 197 | static void |
| 198 | cut_callback(int anchor, int color, struct pattern *pattern, int ll, |
| 199 | void *data) |
| 200 | { |
| 201 | if (pattern->class & CLASS_B) |
| 202 | cut_connect_callback(anchor, color, pattern, ll, data); |
| 203 | } |
| 204 | |
| 205 | |
| 206 | /* Consider C patterns and those without classification. */ |
| 207 | static void |
| 208 | conn_callback(int anchor, int color, struct pattern *pattern, int ll, |
| 209 | void *data) |
| 210 | { |
| 211 | if (!(pattern->class & CLASS_B)) |
| 212 | cut_connect_callback(anchor, color, pattern, ll, data); |
| 213 | } |
| 214 | |
| 215 | /* Find cutting points which should inhibit amalgamations and sever |
| 216 | * the adjacent eye space. |
| 217 | */ |
| 218 | void |
| 219 | find_cuts(void) |
| 220 | { |
| 221 | matchpat(cut_callback, ANCHOR_COLOR, &conn_db, NULL, NULL); |
| 222 | } |
| 223 | |
| 224 | /* Find explicit connection patterns and amalgamate the involved dragons. */ |
| 225 | void |
| 226 | find_connections(void) |
| 227 | { |
| 228 | matchpat(conn_callback, ANCHOR_COLOR, &conn_db, NULL, NULL); |
| 229 | } |
| 230 | |
| 231 | |
| 232 | /* |
| 233 | * Local Variables: |
| 234 | * tab-width: 8 |
| 235 | * c-basic-offset: 2 |
| 236 | * End: |
| 237 | */ |