| 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 "gnugo.h" |
| 25 | |
| 26 | #include <stdio.h> |
| 27 | #include <stdlib.h> |
| 28 | #include <string.h> |
| 29 | #include "liberty.h" |
| 30 | #include "eyes.h" |
| 31 | #include "gg_utils.h" |
| 32 | |
| 33 | #define MAXEYE 20 |
| 34 | |
| 35 | |
| 36 | /* This structure is used in communication between read_eye() and |
| 37 | * recognize_eye(). |
| 38 | */ |
| 39 | struct vital_points { |
| 40 | int attacks[4 * MAXEYE]; |
| 41 | int defenses[4 * MAXEYE]; |
| 42 | int num_attacks; |
| 43 | int num_defenses; |
| 44 | }; |
| 45 | |
| 46 | |
| 47 | static void |
| 48 | compute_primary_domains(int color, int domain[BOARDMAX], |
| 49 | int lively[BOARDMAX], |
| 50 | int false_margins[BOARDMAX], |
| 51 | int first_time); |
| 52 | static void count_neighbours(struct eye_data eyedata[BOARDMAX]); |
| 53 | static int is_lively(int owl_call, int pos); |
| 54 | static int false_margin(int pos, int color, int lively[BOARDMAX]); |
| 55 | static void originate_eye(int origin, int pos, |
| 56 | int *esize, int *msize, |
| 57 | struct eye_data eye[BOARDMAX]); |
| 58 | static int read_eye(int pos, int *attack_point, int *defense_point, |
| 59 | struct eyevalue *value, |
| 60 | struct eye_data eye[BOARDMAX], |
| 61 | struct half_eye_data heye[BOARDMAX], |
| 62 | int add_moves); |
| 63 | static int recognize_eye(int pos, int *attack_point, int *defense_point, |
| 64 | struct eyevalue *value, |
| 65 | struct eye_data eye[BOARDMAX], |
| 66 | struct half_eye_data heye[BOARDMAX], |
| 67 | struct vital_points *vp); |
| 68 | static void guess_eye_space(int pos, int effective_eyesize, int margins, |
| 69 | int bulk_score, struct eye_data eye[BOARDMAX], |
| 70 | struct eyevalue *value, int *pessimistic_min); |
| 71 | static void reset_map(int size); |
| 72 | static void first_map(int *map_value); |
| 73 | static int next_map(int *q, int map[MAXEYE]); |
| 74 | static void print_eye(struct eye_data eye[BOARDMAX], |
| 75 | struct half_eye_data heye[BOARDMAX], int pos); |
| 76 | static void add_false_eye(int pos, struct eye_data eye[BOARDMAX], |
| 77 | struct half_eye_data heye[BOARDMAX]); |
| 78 | static float topological_eye(int pos, int color, |
| 79 | struct eye_data my_eye[BOARDMAX], |
| 80 | struct half_eye_data heye[BOARDMAX]); |
| 81 | static float evaluate_diagonal_intersection(int m, int n, int color, |
| 82 | int *attack_point, |
| 83 | int *defense_point, |
| 84 | struct eye_data my_eye[BOARDMAX]); |
| 85 | |
| 86 | |
| 87 | /* These are used during the calculations of eye spaces. */ |
| 88 | static int black_domain[BOARDMAX]; |
| 89 | static int white_domain[BOARDMAX]; |
| 90 | |
| 91 | /* Used internally by mapping functions. */ |
| 92 | static int map_size; |
| 93 | static signed char used_index[MAXEYE]; |
| 94 | |
| 95 | |
| 96 | /* |
| 97 | * make_domains() is called from make_dragons() and from |
| 98 | * owl_determine_life(). It marks the black and white domains |
| 99 | * (eyeshape regions) and collects some statistics about each one. |
| 100 | */ |
| 101 | |
| 102 | void |
| 103 | make_domains(struct eye_data b_eye[BOARDMAX], |
| 104 | struct eye_data w_eye[BOARDMAX], |
| 105 | int owl_call) |
| 106 | { |
| 107 | int k; |
| 108 | int pos; |
| 109 | int lively[BOARDMAX]; |
| 110 | int false_margins[BOARDMAX]; |
| 111 | |
| 112 | memset(black_domain, 0, sizeof(black_domain)); |
| 113 | memset(white_domain, 0, sizeof(white_domain)); |
| 114 | memset(false_margins, 0, sizeof(false_margins)); |
| 115 | |
| 116 | if (b_eye) |
| 117 | memset(b_eye, 0, BOARDMAX * sizeof(b_eye[0])); |
| 118 | if (w_eye) |
| 119 | memset(w_eye, 0, BOARDMAX * sizeof(w_eye[0])); |
| 120 | |
| 121 | /* Initialize eye data and compute the lively array. */ |
| 122 | for (pos = BOARDMIN; pos < BOARDMAX; pos++) |
| 123 | if (ON_BOARD(pos)) |
| 124 | lively[pos] = is_lively(owl_call, pos); |
| 125 | |
| 126 | /* Compute the domains of influence of each color. */ |
| 127 | compute_primary_domains(BLACK, black_domain, lively, false_margins, 1); |
| 128 | compute_primary_domains(WHITE, white_domain, lively, false_margins, 0); |
| 129 | |
| 130 | /* Now we fill out the arrays b_eye and w_eye with data describing |
| 131 | * each eye shape. |
| 132 | */ |
| 133 | |
| 134 | for (pos = BOARDMIN; pos < BOARDMAX; pos++) { |
| 135 | if (!ON_BOARD(pos)) |
| 136 | continue; |
| 137 | |
| 138 | if (board[pos] == EMPTY || !lively[pos]) { |
| 139 | if (black_domain[pos] == 0 && white_domain[pos] == 0) { |
| 140 | if (w_eye) |
| 141 | w_eye[pos].color = GRAY; |
| 142 | if (b_eye) |
| 143 | b_eye[pos].color = GRAY; |
| 144 | } |
| 145 | else if (black_domain[pos] == 1 && white_domain[pos] == 0 && b_eye) { |
| 146 | b_eye[pos].color = BLACK; |
| 147 | for (k = 0; k < 4; k++) { |
| 148 | int apos = pos + delta[k]; |
| 149 | if (ON_BOARD(apos) && white_domain[apos] && !black_domain[apos]) { |
| 150 | b_eye[pos].marginal = 1; |
| 151 | break; |
| 152 | } |
| 153 | } |
| 154 | } |
| 155 | else if (black_domain[pos] == 0 && white_domain[pos] == 1 && w_eye) { |
| 156 | w_eye[pos].color = WHITE; |
| 157 | for (k = 0; k < 4; k++) { |
| 158 | int apos = pos + delta[k]; |
| 159 | if (ON_BOARD(apos) && black_domain[apos] && !white_domain[apos]) { |
| 160 | w_eye[pos].marginal = 1; |
| 161 | break; |
| 162 | } |
| 163 | } |
| 164 | } |
| 165 | else if (black_domain[pos] == 1 && white_domain[pos] == 1) { |
| 166 | if (b_eye) { |
| 167 | for (k = 0; k < 4; k++) { |
| 168 | int apos = pos + delta[k]; |
| 169 | if (ON_BOARD(apos) && black_domain[apos] |
| 170 | && !white_domain[apos]) { |
| 171 | b_eye[pos].marginal = 1; |
| 172 | b_eye[pos].color = BLACK; |
| 173 | break; |
| 174 | } |
| 175 | } |
| 176 | if (k == 4) |
| 177 | b_eye[pos].color = GRAY; |
| 178 | } |
| 179 | |
| 180 | if (w_eye) { |
| 181 | for (k = 0; k < 4; k++) { |
| 182 | int apos = pos + delta[k]; |
| 183 | if (ON_BOARD(apos) && white_domain[apos] |
| 184 | && !black_domain[apos]) { |
| 185 | w_eye[pos].marginal = 1; |
| 186 | w_eye[pos].color = WHITE; |
| 187 | break; |
| 188 | } |
| 189 | } |
| 190 | if (k == 4) |
| 191 | w_eye[pos].color = GRAY; |
| 192 | } |
| 193 | } |
| 194 | } |
| 195 | } |
| 196 | |
| 197 | /* The eye spaces are all found. Now we need to find the origins. */ |
| 198 | partition_eyespaces(b_eye, BLACK); |
| 199 | partition_eyespaces(w_eye, WHITE); |
| 200 | } |
| 201 | |
| 202 | /* Find connected eyespace components and compute relevant statistics. */ |
| 203 | void |
| 204 | partition_eyespaces(struct eye_data eye[BOARDMAX], int color) |
| 205 | { |
| 206 | int pos; |
| 207 | |
| 208 | if (!eye) |
| 209 | return; |
| 210 | |
| 211 | for (pos = BOARDMIN; pos < BOARDMAX; pos++) |
| 212 | if (ON_BOARD(pos)) |
| 213 | eye[pos].origin = NO_MOVE; |
| 214 | |
| 215 | for (pos = BOARDMIN; pos < BOARDMAX; pos++) { |
| 216 | if (!ON_BOARD(pos)) |
| 217 | continue; |
| 218 | if (eye[pos].origin == NO_MOVE && eye[pos].color == color) { |
| 219 | int esize = 0; |
| 220 | int msize = 0; |
| 221 | |
| 222 | originate_eye(pos, pos, &esize, &msize, eye); |
| 223 | eye[pos].esize = esize; |
| 224 | eye[pos].msize = msize; |
| 225 | } |
| 226 | } |
| 227 | |
| 228 | /* Now we count the number of neighbors and marginal neighbors |
| 229 | * of each vertex. |
| 230 | */ |
| 231 | count_neighbours(eye); |
| 232 | } |
| 233 | |
| 234 | |
| 235 | /* Compute the domains of influence of each color, used in determining |
| 236 | * eye shapes. NOTE: the term influence as used here is distinct from the |
| 237 | * influence in influence.c. |
| 238 | * |
| 239 | * For this algorithm the strings which are not lively are invisible. Ignoring |
| 240 | * these, the algorithm assigns friendly influence to: |
| 241 | * |
| 242 | * (1) every vertex which is occupied by a (lively) friendly stone, |
| 243 | * (2) every empty vertex adjoining a (lively) friendly stone, |
| 244 | * (3) every empty vertex for which two adjoining vertices (not |
| 245 | * on the first line) in the (usually 8) surrounding ones have friendly |
| 246 | * influence, with two CAVEATS explained below. |
| 247 | * |
| 248 | * Thus in the following diagram, e would be assigned friendly influence |
| 249 | * if a and b have friendly influence, or a and d. It is not sufficent |
| 250 | * for b and d to have friendly influence, because they are not adjoining. |
| 251 | * |
| 252 | * uabc |
| 253 | * def |
| 254 | * ghi |
| 255 | * |
| 256 | * The constraint that the two adjoining vertices not lie on the first |
| 257 | * line prevents influence from leaking under a stone on the third line. |
| 258 | * |
| 259 | * The first CAVEAT alluded to above is that even if a and b have friendly |
| 260 | * influence, this does not cause e to have friendly influence if there |
| 261 | * is a lively opponent stone at d. This constraint prevents |
| 262 | * influence from leaking past knight's move extensions. |
| 263 | * |
| 264 | * The second CAVEAT is that even if a and b have friendly influence |
| 265 | * this does not cause e to have influence if there are lively opponent |
| 266 | * stones at u and at c. This prevents influence from leaking past |
| 267 | * nikken tobis (two space jumps). |
| 268 | * |
| 269 | * The corner vertices are handled slightly different. |
| 270 | * |
| 271 | * +--- |
| 272 | * |ab |
| 273 | * |cd |
| 274 | * |
| 275 | * We get friendly influence at a if we have friendly influence |
| 276 | * at b or c and no lively unfriendly stone at b, c or d. |
| 277 | * |
| 278 | */ |
| 279 | |
| 280 | #define sufficient_influence(pos, apos, bpos) \ |
| 281 | (ON_BOARD(bpos) && influence[bpos] > threshold[pos] - influence[apos]) |
| 282 | |
| 283 | static void |
| 284 | compute_primary_domains(int color, int domain[BOARDMAX], |
| 285 | int lively[BOARDMAX], |
| 286 | int false_margins[BOARDMAX], |
| 287 | int first_time) |
| 288 | { |
| 289 | int other = OTHER_COLOR(color); |
| 290 | int i, j, k; |
| 291 | int pos, pos2; |
| 292 | int own, enemy; |
| 293 | signed char threshold[BOARDMAX]; |
| 294 | signed char influence[BOARDMAX]; |
| 295 | int list[BOARDMAX]; |
| 296 | int size = 0, lastchange = 0; |
| 297 | |
| 298 | memset(threshold, 0, sizeof(threshold)); |
| 299 | memset(influence, 0, sizeof(influence)); |
| 300 | |
| 301 | /* In the first pass we |
| 302 | * 1. Give influence to lively own stones and their neighbors. |
| 303 | * (Cases (1) and (2) above.) |
| 304 | * 2. Fill influence[] and threshold[] arrays with initial values. |
| 305 | */ |
| 306 | for (pos = BOARDMIN; pos < BOARDMAX; pos++) { |
| 307 | if (!ON_BOARD(pos)) |
| 308 | continue; |
| 309 | |
| 310 | if (lively[pos]) { |
| 311 | if (board[pos] == color) { |
| 312 | domain[pos] = 1; /* Case (1) above. */ |
| 313 | influence[pos] = 1; |
| 314 | } |
| 315 | else |
| 316 | influence[pos] = -1; |
| 317 | continue; |
| 318 | } |
| 319 | |
| 320 | own = enemy = 0; |
| 321 | for (k = 0; k < 4; k++) { |
| 322 | pos2 = pos + delta[k]; |
| 323 | if (ON_BOARD(pos2) && lively[pos2]) { |
| 324 | if (board[pos2] == color) |
| 325 | own = 1; |
| 326 | else |
| 327 | enemy = 1; |
| 328 | } |
| 329 | } |
| 330 | |
| 331 | if (own) { |
| 332 | /* To explain the asymmetry between the first time around |
| 333 | * this loop and subsequent ones, a false margin is adjacent |
| 334 | * to both B and W lively stones, so it's found on the first |
| 335 | * pass through the loop. |
| 336 | */ |
| 337 | if (first_time) { |
| 338 | if (board[pos] == EMPTY && (false_margin(pos, color, lively) |
| 339 | || false_margin(pos, other, lively))) |
| 340 | false_margins[pos] = 1; |
| 341 | else { |
| 342 | domain[pos] = 1; |
| 343 | influence[pos] = 1; |
| 344 | } |
| 345 | } |
| 346 | else if (board[pos] != EMPTY || !false_margins[pos]) { |
| 347 | domain[pos] = 1; |
| 348 | influence[pos] = 1; |
| 349 | } |
| 350 | } |
| 351 | else |
| 352 | list[size++] = pos; |
| 353 | |
| 354 | if (enemy) { |
| 355 | threshold[pos] = 1; |
| 356 | influence[pos]--; |
| 357 | } |
| 358 | else if (is_edge_vertex(pos)) |
| 359 | influence[pos]--; |
| 360 | } |
| 361 | |
| 362 | /* Now we loop over the board until no more vertices can be added to |
| 363 | * the domain through case (3) above. |
| 364 | */ |
| 365 | if (size) { |
| 366 | k = size; |
| 367 | while (1) { |
| 368 | if (!k) |
| 369 | k = size; |
| 370 | pos = list[--k]; |
| 371 | |
| 372 | /* Case (3) above. */ |
| 373 | if (sufficient_influence(pos, SOUTH(pos), SE(pos)) |
| 374 | || sufficient_influence(pos, SOUTH(pos), SW(pos)) |
| 375 | || sufficient_influence(pos, EAST(pos), SE(pos)) |
| 376 | || sufficient_influence(pos, EAST(pos), NE(pos)) |
| 377 | || sufficient_influence(pos, WEST(pos), SW(pos)) |
| 378 | || sufficient_influence(pos, WEST(pos), NW(pos)) |
| 379 | || sufficient_influence(pos, NORTH(pos), NW(pos)) |
| 380 | || sufficient_influence(pos, NORTH(pos), NE(pos))) { |
| 381 | domain[pos] = 1; |
| 382 | influence[pos]++; |
| 383 | |
| 384 | if (!--size) |
| 385 | break; |
| 386 | if (k < size) |
| 387 | list[k] = list[size]; |
| 388 | else |
| 389 | k--; |
| 390 | lastchange = k; |
| 391 | } |
| 392 | else if (k == lastchange) |
| 393 | break; /* Looped the whole list and found nothing new */ |
| 394 | } |
| 395 | } |
| 396 | |
| 397 | if (0 && (debug & DEBUG_EYES)) { |
| 398 | start_draw_board(); |
| 399 | for (i = 0; i < board_size; i++) |
| 400 | for (j = 0; j < board_size; j++) { |
| 401 | draw_color_char(i, j, domain[POS(i, j)] ? '1' : '0', GG_COLOR_BLACK); |
| 402 | } |
| 403 | end_draw_board(); |
| 404 | } |
| 405 | } |
| 406 | |
| 407 | |
| 408 | static void |
| 409 | count_neighbours(struct eye_data eyedata[BOARDMAX]) |
| 410 | { |
| 411 | int pos; |
| 412 | int k; |
| 413 | |
| 414 | for (pos = BOARDMIN; pos < BOARDMAX; pos++) { |
| 415 | if (!ON_BOARD(pos) || eyedata[pos].origin == NO_MOVE) |
| 416 | continue; |
| 417 | |
| 418 | eyedata[pos].esize = eyedata[eyedata[pos].origin].esize; |
| 419 | eyedata[pos].msize = eyedata[eyedata[pos].origin].msize; |
| 420 | eyedata[pos].neighbors = 0; |
| 421 | eyedata[pos].marginal_neighbors = 0; |
| 422 | |
| 423 | for (k = 0; k < 4; k++) { |
| 424 | int pos2 = pos + delta[k]; |
| 425 | if (ON_BOARD(pos2) && eyedata[pos2].origin == eyedata[pos].origin) { |
| 426 | eyedata[pos].neighbors++; |
| 427 | if (eyedata[pos2].marginal) |
| 428 | eyedata[pos].marginal_neighbors++; |
| 429 | } |
| 430 | } |
| 431 | } |
| 432 | } |
| 433 | |
| 434 | |
| 435 | static int |
| 436 | is_lively(int owl_call, int pos) |
| 437 | { |
| 438 | if (board[pos] == EMPTY) |
| 439 | return 0; |
| 440 | |
| 441 | if (owl_call) |
| 442 | return owl_lively(pos); |
| 443 | else |
| 444 | return (!worm[pos].inessential |
| 445 | && (worm[pos].attack_codes[0] == 0 |
| 446 | || worm[pos].defense_codes[0] != 0)); |
| 447 | } |
| 448 | |
| 449 | |
| 450 | /* In the following situation, we do not wish the vertex at 'a' |
| 451 | * included in the O eye space: |
| 452 | * |
| 453 | * OOOOXX |
| 454 | * OXaX.. |
| 455 | * ------ |
| 456 | * |
| 457 | * This eyespace should parse as (X), not (X!). Thus the vertex |
| 458 | * should not be included in the eyespace if it is adjacent to |
| 459 | * an X stone which is alive, yet X cannot play safely at a. |
| 460 | * The function returns 1 if this situation is found at |
| 461 | * (pos) for color O. |
| 462 | * |
| 463 | * The condition above is true, curiously enough, also for the |
| 464 | * following case: |
| 465 | * A group has two eyes, one of size 1 and one which is critical 1/2. |
| 466 | * It also has to have less than 4 external liberties, since the |
| 467 | * reading has to be able to capture the group tactically. In that |
| 468 | * case, the eye of size one will be treated as a false marginal. |
| 469 | * Thus we have to exclude this case, which is done by requiring (pos) |
| 470 | * to be adjacent to both white and black stones. Since this test is |
| 471 | * least expensive, we start with it. |
| 472 | * |
| 473 | * As a second optimization we require that one of the other colored |
| 474 | * neighbors is not lively. This should cut down on the number of |
| 475 | * calls to attack() and safe_move(). |
| 476 | */ |
| 477 | |
| 478 | static int |
| 479 | false_margin(int pos, int color, int lively[BOARDMAX]) |
| 480 | { |
| 481 | int other = OTHER_COLOR(color); |
| 482 | int neighbors = 0; |
| 483 | int k; |
| 484 | int all_lively; |
| 485 | int potential_false_margin; |
| 486 | |
| 487 | /* Require neighbors of both colors. */ |
| 488 | for (k = 0; k < 4; k++) |
| 489 | if (ON_BOARD(pos + delta[k])) |
| 490 | neighbors |= board[pos + delta[k]]; |
| 491 | |
| 492 | if (neighbors != (WHITE | BLACK)) |
| 493 | return 0; |
| 494 | |
| 495 | /* At least one opponent neighbor should be not lively. */ |
| 496 | all_lively = 1; |
| 497 | for (k = 0; k < 4; k++) |
| 498 | if (board[pos + delta[k]] == other && !lively[pos + delta[k]]) |
| 499 | all_lively = 0; |
| 500 | |
| 501 | if (all_lively) |
| 502 | return 0; |
| 503 | |
| 504 | potential_false_margin = 0; |
| 505 | for (k = 0; k < 4; k++) { |
| 506 | int apos = pos + delta[k]; |
| 507 | if (board[apos] != other || !lively[apos]) |
| 508 | continue; |
| 509 | |
| 510 | if (stackp == 0 && worm[apos].attack_codes[0] == 0) |
| 511 | potential_false_margin = 1; |
| 512 | |
| 513 | if (stackp > 0 && !attack(apos, NULL)) |
| 514 | potential_false_margin = 1; |
| 515 | } |
| 516 | |
| 517 | if (potential_false_margin && safe_move(pos, other) == 0) { |
| 518 | DEBUG(DEBUG_EYES, "False margin for %C at %1m.\n", color, pos); |
| 519 | return 1; |
| 520 | } |
| 521 | |
| 522 | return 0; |
| 523 | } |
| 524 | |
| 525 | |
| 526 | /* |
| 527 | * originate_eye(pos, pos, *esize, *msize, eye) creates an eyeshape |
| 528 | * with origin pos. esize and msize return the size and the number of |
| 529 | * marginal vertices. The repeated variables (pos) are due to the |
| 530 | * recursive definition of the function. |
| 531 | */ |
| 532 | static void |
| 533 | originate_eye(int origin, int pos, |
| 534 | int *esize, int *msize, |
| 535 | struct eye_data eye[BOARDMAX]) |
| 536 | { |
| 537 | int k; |
| 538 | ASSERT_ON_BOARD1(origin); |
| 539 | ASSERT_ON_BOARD1(pos); |
| 540 | gg_assert(esize != NULL); |
| 541 | gg_assert(msize != NULL); |
| 542 | |
| 543 | eye[pos].origin = origin; |
| 544 | (*esize)++; |
| 545 | if (eye[pos].marginal) |
| 546 | (*msize)++; |
| 547 | |
| 548 | for (k = 0; k < 4; k++) { |
| 549 | int pos2 = pos + delta[k]; |
| 550 | if (ON_BOARD(pos2) |
| 551 | && eye[pos2].color == eye[pos].color |
| 552 | && eye[pos2].origin == NO_MOVE |
| 553 | && (!eye[pos2].marginal || !eye[pos].marginal)) |
| 554 | originate_eye(origin, pos2, esize, msize, eye); |
| 555 | } |
| 556 | } |
| 557 | |
| 558 | |
| 559 | /* |
| 560 | * propagate_eye(origin) copies the data at the (origin) to the |
| 561 | * rest of the eye (invariant fields only). |
| 562 | */ |
| 563 | |
| 564 | void |
| 565 | propagate_eye(int origin, struct eye_data eye[BOARDMAX]) |
| 566 | { |
| 567 | int pos; |
| 568 | |
| 569 | for (pos = BOARDMIN; pos < BOARDMAX; pos++) |
| 570 | if (ON_BOARD(pos) && eye[pos].origin == origin) { |
| 571 | eye[pos].color = eye[origin].color; |
| 572 | eye[pos].esize = eye[origin].esize; |
| 573 | eye[pos].msize = eye[origin].msize; |
| 574 | eye[pos].origin = eye[origin].origin; |
| 575 | eye[pos].value = eye[origin].value; |
| 576 | } |
| 577 | } |
| 578 | |
| 579 | |
| 580 | /* Find the dragon or dragons surrounding an eye space. Up to |
| 581 | * max_dragons dragons adjacent to the eye space are added to |
| 582 | * the dragon array, and the number of dragons found is returned. |
| 583 | */ |
| 584 | |
| 585 | int |
| 586 | find_eye_dragons(int origin, struct eye_data eye[BOARDMAX], int eye_color, |
| 587 | int dragons[], int max_dragons) |
| 588 | { |
| 589 | int mx[BOARDMAX]; |
| 590 | int num_dragons = 0; |
| 591 | int pos; |
| 592 | |
| 593 | memset(mx, 0, sizeof(mx)); |
| 594 | DEBUG(DEBUG_MISCELLANEOUS, "find_eye_dragons: %1m %C\n", origin, eye_color); |
| 595 | for (pos = BOARDMIN; pos < BOARDMAX; pos++) { |
| 596 | if (board[pos] == eye_color |
| 597 | && mx[dragon[pos].origin] == 0 |
| 598 | && ((ON_BOARD(SOUTH(pos)) |
| 599 | && eye[SOUTH(pos)].origin == origin |
| 600 | && !eye[SOUTH(pos)].marginal) |
| 601 | || (ON_BOARD(WEST(pos)) |
| 602 | && eye[WEST(pos)].origin == origin |
| 603 | && !eye[WEST(pos)].marginal) |
| 604 | || (ON_BOARD(NORTH(pos)) |
| 605 | && eye[NORTH(pos)].origin == origin |
| 606 | && !eye[NORTH(pos)].marginal) |
| 607 | || (ON_BOARD(EAST(pos)) |
| 608 | && eye[EAST(pos)].origin == origin |
| 609 | && !eye[EAST(pos)].marginal))) { |
| 610 | DEBUG(DEBUG_MISCELLANEOUS, |
| 611 | " dragon: %1m %1m\n", pos, dragon[pos].origin); |
| 612 | mx[dragon[pos].origin] = 1; |
| 613 | if (dragons != NULL && num_dragons < max_dragons) |
| 614 | dragons[num_dragons] = dragon[pos].origin; |
| 615 | num_dragons++; |
| 616 | } |
| 617 | } |
| 618 | |
| 619 | return num_dragons; |
| 620 | } |
| 621 | |
| 622 | /* Print debugging data for the eyeshape at (i,j). Useful with GDB. |
| 623 | */ |
| 624 | |
| 625 | static void |
| 626 | print_eye(struct eye_data eye[BOARDMAX], struct half_eye_data heye[BOARDMAX], |
| 627 | int pos) |
| 628 | { |
| 629 | int m, n; |
| 630 | int pos2; |
| 631 | int mini, maxi; |
| 632 | int minj, maxj; |
| 633 | int origin = eye[pos].origin; |
| 634 | |
| 635 | gprintf("Eyespace at %1m: color=%C, esize=%d, msize=%d\n", |
| 636 | pos, eye[pos].color, eye[pos].esize, eye[pos].msize); |
| 637 | |
| 638 | for (pos2 = BOARDMIN; pos2 < BOARDMAX; pos2++) { |
| 639 | if (!ON_BOARD(pos2)) |
| 640 | continue; |
| 641 | |
| 642 | if (eye[pos2].origin != pos) |
| 643 | continue; |
| 644 | |
| 645 | if (eye[pos2].marginal && IS_STONE(board[pos2])) |
| 646 | gprintf("%1m (X!)\n", pos2); |
| 647 | else if (is_halfeye(heye, pos2) && IS_STONE(board[pos2])) { |
| 648 | if (heye[pos2].value == 3.0) |
| 649 | gprintf("%1m (XH)\n", pos2); |
| 650 | else |
| 651 | gprintf("%1m (XH) (topological eye value = %f)\n", pos2, |
| 652 | heye[pos2].value); |
| 653 | } |
| 654 | else if (!eye[pos2].marginal && IS_STONE(board[pos2])) |
| 655 | gprintf("%1m (X)\n", pos2); |
| 656 | else if (eye[pos2].marginal && board[pos2] == EMPTY) |
| 657 | gprintf("%1m (!)\n", pos2); |
| 658 | else if (is_halfeye(heye, pos2) && board[pos2] == EMPTY) { |
| 659 | if (heye[pos2].value == 3.0) |
| 660 | gprintf("%1m (H)\n", pos2); |
| 661 | else |
| 662 | gprintf("%1m (H) (topological eye value = %f)\n", pos2, |
| 663 | heye[pos2].value); |
| 664 | } |
| 665 | else |
| 666 | gprintf("%1m\n", pos2); |
| 667 | } |
| 668 | gprintf("\n"); |
| 669 | |
| 670 | /* Determine the size of the eye. */ |
| 671 | mini = board_size; |
| 672 | maxi = -1; |
| 673 | minj = board_size; |
| 674 | maxj = -1; |
| 675 | for (m = 0; m < board_size; m++) |
| 676 | for (n = 0; n < board_size; n++) { |
| 677 | if (eye[POS(m, n)].origin != origin) |
| 678 | continue; |
| 679 | |
| 680 | if (m < mini) mini = m; |
| 681 | if (m > maxi) maxi = m; |
| 682 | if (n < minj) minj = n; |
| 683 | if (n > maxj) maxj = n; |
| 684 | } |
| 685 | |
| 686 | /* Prints the eye shape. A half eye is shown by h, if empty or H, if an |
| 687 | * enemy is present. Note that each half eye has a marginal point which is |
| 688 | * not printed, so the representation here may have less points than the |
| 689 | * matching eye pattern in eyes.db. Printing a marginal for the half eye |
| 690 | * would be nice, but difficult to implement. |
| 691 | */ |
| 692 | for (m = mini; m <= maxi; m++) { |
| 693 | gprintf(""); /* Get the indentation right. */ |
| 694 | for (n = minj; n <= maxj; n++) { |
| 695 | int pos2 = POS(m, n); |
| 696 | if (eye[pos2].origin == origin) { |
| 697 | if (board[pos2] == EMPTY) { |
| 698 | if (eye[pos2].marginal) |
| 699 | gprintf("%o!"); |
| 700 | else if (is_halfeye(heye, pos2)) |
| 701 | gprintf("%oh"); |
| 702 | else |
| 703 | gprintf("%o."); |
| 704 | } |
| 705 | else if (is_halfeye(heye, pos2)) |
| 706 | gprintf("%oH"); |
| 707 | else |
| 708 | gprintf("%oX"); |
| 709 | } |
| 710 | else |
| 711 | gprintf("%o "); |
| 712 | } |
| 713 | gprintf("\n"); |
| 714 | } |
| 715 | } |
| 716 | |
| 717 | |
| 718 | /* |
| 719 | * Given an eyespace with origin (pos), this function computes the |
| 720 | * minimum and maximum numbers of eyes the space can yield. If max and |
| 721 | * min are different, then vital points of attack and defense are also |
| 722 | * generated. |
| 723 | * |
| 724 | * If add_moves == 1, this function may add a move_reason for (color) at |
| 725 | * a vital point which is found by the function. If add_moves == 0, |
| 726 | * set color == EMPTY. |
| 727 | */ |
| 728 | |
| 729 | void |
| 730 | compute_eyes(int pos, struct eyevalue *value, |
| 731 | int *attack_point, int *defense_point, |
| 732 | struct eye_data eye[BOARDMAX], |
| 733 | struct half_eye_data heye[BOARDMAX], int add_moves) |
| 734 | { |
| 735 | if (attack_point) |
| 736 | *attack_point = NO_MOVE; |
| 737 | if (defense_point) |
| 738 | *defense_point = NO_MOVE; |
| 739 | |
| 740 | if (debug & DEBUG_EYES) { |
| 741 | print_eye(eye, heye, pos); |
| 742 | DEBUG(DEBUG_EYES, "\n"); |
| 743 | } |
| 744 | |
| 745 | /* Look up the eye space in the graphs database. */ |
| 746 | if (read_eye(pos, attack_point, defense_point, value, eye, heye, add_moves)) |
| 747 | return; |
| 748 | |
| 749 | /* Ideally any eye space that hasn't been matched yet should be two |
| 750 | * secure eyes. Until the database becomes more complete we have |
| 751 | * some additional heuristics to guess the values of unknown |
| 752 | * eyespaces. |
| 753 | */ |
| 754 | if (eye[pos].esize - 2*eye[pos].msize > 3) |
| 755 | set_eyevalue(value, 2, 2, 2, 2); |
| 756 | else if (eye[pos].esize - 2*eye[pos].msize > 0) |
| 757 | set_eyevalue(value, 1, 1, 1, 1); |
| 758 | else |
| 759 | set_eyevalue(value, 0, 0, 0, 0); |
| 760 | } |
| 761 | |
| 762 | |
| 763 | /* |
| 764 | * This function works like compute_eyes(), except that it also gives |
| 765 | * a pessimistic view of the chances to make eyes. Since it is intended |
| 766 | * to be used from the owl code, the option to add move reasons has |
| 767 | * been removed. |
| 768 | */ |
| 769 | void |
| 770 | compute_eyes_pessimistic(int pos, struct eyevalue *value, |
| 771 | int *pessimistic_min, |
| 772 | int *attack_point, int *defense_point, |
| 773 | struct eye_data eye[BOARDMAX], |
| 774 | struct half_eye_data heye[BOARDMAX]) |
| 775 | { |
| 776 | static int bulk_coefficients[5] = {-1, -1, 1, 4, 12}; |
| 777 | |
| 778 | int pos2; |
| 779 | int margins = 0; |
| 780 | int halfeyes = 0; |
| 781 | int margins_adjacent_to_margin = 0; |
| 782 | int effective_eyesize; |
| 783 | int bulk_score = 0; |
| 784 | signed char chainlinks[BOARDMAX]; |
| 785 | |
| 786 | /* Stones inside eyespace which do not coincide with a false eye or |
| 787 | * a halfeye. |
| 788 | */ |
| 789 | int interior_stones = 0; |
| 790 | |
| 791 | memset(chainlinks, 0, BOARDMAX); |
| 792 | |
| 793 | for (pos2 = BOARDMIN; pos2 < BOARDMAX; pos2++) { |
| 794 | int k; |
| 795 | |
| 796 | if (!ON_BOARD(pos2) || eye[pos2].origin != pos) |
| 797 | continue; |
| 798 | |
| 799 | if (eye[pos2].marginal || is_halfeye(heye, pos2)) { |
| 800 | margins++; |
| 801 | if (eye[pos2].marginal && eye[pos2].marginal_neighbors > 0) |
| 802 | margins_adjacent_to_margin++; |
| 803 | if (is_halfeye(heye, pos2)) |
| 804 | halfeyes++; |
| 805 | } |
| 806 | else if (IS_STONE(board[pos2])) |
| 807 | interior_stones++; |
| 808 | |
| 809 | bulk_score += bulk_coefficients[(int) eye[pos2].neighbors]; |
| 810 | |
| 811 | for (k = 0; k < 4; k++) { |
| 812 | int neighbor = pos2 + delta[k]; |
| 813 | |
| 814 | if (board[neighbor] == eye[pos].color) { |
| 815 | if (!chainlinks[neighbor]) { |
| 816 | bulk_score += 4; |
| 817 | mark_string(neighbor, chainlinks, 1); |
| 818 | } |
| 819 | } |
| 820 | else if (!ON_BOARD(neighbor)) |
| 821 | bulk_score += 2; |
| 822 | } |
| 823 | } |
| 824 | |
| 825 | /* This is a measure based on the simplified assumption that both |
| 826 | * players only cares about playing the marginal eye spaces. It is |
| 827 | * used later to guess the eye value for unidentified eye shapes. |
| 828 | */ |
| 829 | effective_eyesize = (eye[pos].esize + halfeyes - 2*margins |
| 830 | - margins_adjacent_to_margin); |
| 831 | |
| 832 | if (attack_point) |
| 833 | *attack_point = NO_MOVE; |
| 834 | if (defense_point) |
| 835 | *defense_point = NO_MOVE; |
| 836 | |
| 837 | if (debug & DEBUG_EYES) { |
| 838 | print_eye(eye, heye, pos); |
| 839 | DEBUG(DEBUG_EYES, "\n"); |
| 840 | } |
| 841 | |
| 842 | /* Look up the eye space in the graphs database. */ |
| 843 | if (read_eye(pos, attack_point, defense_point, value, |
| 844 | eye, heye, 0)) { |
| 845 | *pessimistic_min = min_eyes(value) - margins; |
| 846 | |
| 847 | /* A single point eye which is part of a ko can't be trusted. */ |
| 848 | if (eye[pos].esize == 1 |
| 849 | && is_ko(pos, OTHER_COLOR(eye[pos].color), NULL)) |
| 850 | *pessimistic_min = 0; |
| 851 | |
| 852 | DEBUG(DEBUG_EYES, " graph matching - %s, pessimistic_min=%d\n", |
| 853 | eyevalue_to_string(value), *pessimistic_min); |
| 854 | } |
| 855 | |
| 856 | /* Ideally any eye space that hasn't been matched yet should be two |
| 857 | * secure eyes. Until the database becomes more complete we have |
| 858 | * some additional heuristics to guess the values of unknown |
| 859 | * eyespaces. |
| 860 | */ |
| 861 | else { |
| 862 | guess_eye_space(pos, effective_eyesize, margins, bulk_score, eye, |
| 863 | value, pessimistic_min); |
| 864 | DEBUG(DEBUG_EYES, " guess_eye - %s, pessimistic_min=%d\n", |
| 865 | eyevalue_to_string(value), *pessimistic_min); |
| 866 | } |
| 867 | |
| 868 | if (*pessimistic_min < 0) { |
| 869 | *pessimistic_min = 0; |
| 870 | DEBUG(DEBUG_EYES, " pessimistic min revised to 0\n"); |
| 871 | } |
| 872 | |
| 873 | /* An eyespace with at least two interior stones is assumed to be |
| 874 | * worth at least one eye, regardless of previous considerations. |
| 875 | */ |
| 876 | if (*pessimistic_min < 1 && interior_stones >= 2) { |
| 877 | *pessimistic_min = 1; |
| 878 | DEBUG(DEBUG_EYES, " pessimistic min revised to 1 (interior stones)\n"); |
| 879 | } |
| 880 | |
| 881 | if (attack_point |
| 882 | && *attack_point == NO_MOVE |
| 883 | && max_eyes(value) != *pessimistic_min) { |
| 884 | /* Find one marginal vertex and set as attack and defense point. |
| 885 | * |
| 886 | * We make some effort to find the best marginal vertex by giving |
| 887 | * priority to ones with more than one neighbor in the eyespace. |
| 888 | * We prefer non-halfeye margins and ones which are not self-atari |
| 889 | * for the opponent. Margins not on the edge are also favored. |
| 890 | */ |
| 891 | int best_attack_point = NO_MOVE; |
| 892 | int best_defense_point = NO_MOVE; |
| 893 | float score = 0.0; |
| 894 | |
| 895 | for (pos2 = BOARDMIN; pos2 < BOARDMAX; pos2++) { |
| 896 | if (ON_BOARD(pos2) && eye[pos2].origin == pos) { |
| 897 | float this_score = 0.0; |
| 898 | int this_attack_point = NO_MOVE; |
| 899 | int this_defense_point = NO_MOVE; |
| 900 | if (eye[pos2].marginal && board[pos2] == EMPTY) { |
| 901 | this_score = eye[pos2].neighbors; |
| 902 | this_attack_point = pos2; |
| 903 | this_defense_point = pos2; |
| 904 | |
| 905 | if (is_self_atari(pos2, OTHER_COLOR(eye[pos].color))) |
| 906 | this_score -= 0.5; |
| 907 | |
| 908 | if (is_edge_vertex(pos2)) |
| 909 | this_score -= 0.1; |
| 910 | } |
| 911 | else if (is_halfeye(heye, pos2)) { |
| 912 | this_score = 0.75; |
| 913 | this_defense_point = heye[pos2].defense_point[0]; |
| 914 | this_attack_point = heye[pos2].attack_point[0]; |
| 915 | } |
| 916 | else |
| 917 | continue; |
| 918 | |
| 919 | if (gg_normalize_float2int(this_score, 0.01) |
| 920 | > gg_normalize_float2int(score, 0.01)) { |
| 921 | best_attack_point = this_attack_point; |
| 922 | best_defense_point = this_defense_point; |
| 923 | score = this_score; |
| 924 | } |
| 925 | } |
| 926 | } |
| 927 | |
| 928 | if (score > 0.0) { |
| 929 | if (defense_point) |
| 930 | *defense_point = best_defense_point; |
| 931 | if (attack_point) |
| 932 | *attack_point = best_attack_point; |
| 933 | } |
| 934 | } |
| 935 | |
| 936 | if (defense_point && *defense_point != NO_MOVE) { |
| 937 | ASSERT_ON_BOARD1(*defense_point); |
| 938 | } |
| 939 | if (attack_point && *attack_point != NO_MOVE) { |
| 940 | ASSERT_ON_BOARD1(*attack_point); |
| 941 | } |
| 942 | } |
| 943 | |
| 944 | |
| 945 | static void |
| 946 | guess_eye_space(int pos, int effective_eyesize, int margins, |
| 947 | int bulk_score, struct eye_data eye[BOARDMAX], |
| 948 | struct eyevalue *value, int *pessimistic_min) |
| 949 | { |
| 950 | if (effective_eyesize > 3) { |
| 951 | set_eyevalue(value, 2, 2, 2, 2); |
| 952 | *pessimistic_min = 1; |
| 953 | |
| 954 | if ((margins == 0 && effective_eyesize > 7) |
| 955 | || (margins > 0 && effective_eyesize > 9)) { |
| 956 | int eyes = 2 + (effective_eyesize - 2 * (margins > 0) - 8) / 2; |
| 957 | int threshold = (4 * (eye[pos].esize - 2) |
| 958 | + (effective_eyesize - 8) * (effective_eyesize - 9)); |
| 959 | |
| 960 | DEBUG(DEBUG_EYES, "size: %d(%d), threshold: %d, bulk score: %d\n", |
| 961 | eye[pos].esize, effective_eyesize, threshold, bulk_score); |
| 962 | |
| 963 | if (bulk_score > threshold && effective_eyesize < 15) |
| 964 | eyes = gg_max(2, eyes - ((bulk_score - threshold) / eye[pos].esize)); |
| 965 | |
| 966 | if (bulk_score < threshold + eye[pos].esize || effective_eyesize >= 15) |
| 967 | *pessimistic_min = eyes; |
| 968 | |
| 969 | set_eyevalue(value, eyes, eyes, eyes, eyes); |
| 970 | } |
| 971 | } |
| 972 | else if (effective_eyesize > 0) { |
| 973 | set_eyevalue(value, 1, 1, 1, 1); |
| 974 | if (margins > 0) |
| 975 | *pessimistic_min = 0; |
| 976 | else |
| 977 | *pessimistic_min = 1; |
| 978 | } |
| 979 | else { |
| 980 | if (eye[pos].esize - margins > 2) |
| 981 | set_eyevalue(value, 0, 0, 1, 1); |
| 982 | else |
| 983 | set_eyevalue(value, 0, 0, 0, 0); |
| 984 | *pessimistic_min = 0; |
| 985 | } |
| 986 | } |
| 987 | |
| 988 | |
| 989 | /* This function does some minor reading to improve the results of |
| 990 | * recognize_eye(). Currently, it has two duties. One is to read |
| 991 | * positions like this: |
| 992 | * |
| 993 | * .XXXX| with half eye with proper eye |
| 994 | * XXOOO| |
| 995 | * XO.O.| . (1 eye) . (2 eyes) |
| 996 | * XXOa.| !.. .* |
| 997 | * -----+ |
| 998 | * |
| 999 | * recognize_eye() sees the eyespace of the white dragon as shown |
| 1000 | * (there's a half eye at a and it is considered the same as '!.' by |
| 1001 | * the optics code). Normally, that eye shape gives only one secure |
| 1002 | * eye, and owl thinks that the white dragon is dead unconditionally. |
| 1003 | * This function tries to turn such ko-dependent half eyes into proper |
| 1004 | * eyes and chooses the best alternative. Note that we don't have any |
| 1005 | * attack/defense codes here, since owl will determine them itself. |
| 1006 | * |
| 1007 | * Another one is related to some cases when replacing half eyes with |
| 1008 | * '!.' doesn't work. E.g. consider this eye (optics:328): |
| 1009 | * |
| 1010 | * XXXOO eye graph is 310: |
| 1011 | * X..X. |
| 1012 | * XOXX. !.! (second '!' is due to the halfeye) |
| 1013 | * OXO.. |
| 1014 | * O.O.. |
| 1015 | * |
| 1016 | * When this function detects such a half eye that can be attacked |
| 1017 | * and/or defended inside its eyespace, it tries to turn it into a |
| 1018 | * proper eye and see what happens. In case it gives an improvement |
| 1019 | * for attacker and/or defender, the function keeps new result but |
| 1020 | * only if new vital points are also vital points for the half eye. |
| 1021 | * The heuristics used here might need improvements since they are |
| 1022 | * based on a single game position. |
| 1023 | * |
| 1024 | * If add_moves != 0, this function may add move reasons for (color) |
| 1025 | * at the vital points which are found by recognize_eye(). If add_moves |
| 1026 | * == 0, set color to be EMPTY. |
| 1027 | */ |
| 1028 | static int |
| 1029 | read_eye(int pos, int *attack_point, int *defense_point, |
| 1030 | struct eyevalue *value, struct eye_data eye[BOARDMAX], |
| 1031 | struct half_eye_data heye[BOARDMAX], |
| 1032 | int add_moves) |
| 1033 | { |
| 1034 | int eye_color; |
| 1035 | int k; |
| 1036 | int pos2; |
| 1037 | int combination_halfeye = NO_MOVE; |
| 1038 | int combination_attack = NO_MOVE; |
| 1039 | int combination_defense = NO_MOVE; |
| 1040 | int num_ko_halfeyes = 0; |
| 1041 | int ko_halfeye = NO_MOVE; |
| 1042 | struct vital_points vp; |
| 1043 | struct vital_points ko_vp; |
| 1044 | struct vital_points *best_vp = &vp; |
| 1045 | |
| 1046 | eye_color = recognize_eye(pos, attack_point, defense_point, value, |
| 1047 | eye, heye, &vp); |
| 1048 | if (!eye_color) |
| 1049 | return 0; |
| 1050 | |
| 1051 | /* Find ko half eyes and "combination" half eyes if any. */ |
| 1052 | for (pos2 = BOARDMIN; pos2 < BOARDMAX; pos2++) { |
| 1053 | if (ON_BOARD(pos2) |
| 1054 | && eye[pos2].origin == pos |
| 1055 | && heye[pos2].type == HALF_EYE) { |
| 1056 | if (combination_halfeye == NO_MOVE) { |
| 1057 | int apos = NO_MOVE; |
| 1058 | int dpos = NO_MOVE; |
| 1059 | |
| 1060 | for (k = 0; k < heye[pos2].num_attacks; k++) { |
| 1061 | if (eye[heye[pos2].attack_point[k]].origin == pos) { |
| 1062 | apos = heye[pos2].attack_point[k]; |
| 1063 | break; |
| 1064 | } |
| 1065 | } |
| 1066 | |
| 1067 | for (k = 0; k < heye[pos2].num_defenses; k++) { |
| 1068 | if (eye[heye[pos2].defense_point[k]].origin == pos) { |
| 1069 | dpos = heye[pos2].defense_point[k]; |
| 1070 | break; |
| 1071 | } |
| 1072 | } |
| 1073 | |
| 1074 | if (apos || dpos) { |
| 1075 | combination_halfeye = pos2; |
| 1076 | combination_attack = apos; |
| 1077 | combination_defense = dpos; |
| 1078 | } |
| 1079 | } |
| 1080 | |
| 1081 | if (heye[pos2].value < 3.0) { |
| 1082 | num_ko_halfeyes++; |
| 1083 | ko_halfeye = pos2; |
| 1084 | } |
| 1085 | } |
| 1086 | } |
| 1087 | |
| 1088 | /* In case we have a "combination" half eye, turn it into a proper eye |
| 1089 | * vertex for a while and see what happens. |
| 1090 | */ |
| 1091 | if (combination_halfeye != NO_MOVE) { |
| 1092 | int result; |
| 1093 | int apos = NO_MOVE; |
| 1094 | int dpos = NO_MOVE; |
| 1095 | struct eyevalue combination_value; |
| 1096 | struct vital_points combination_vp; |
| 1097 | |
| 1098 | heye[combination_halfeye].type = 0; |
| 1099 | result = recognize_eye(pos, &apos, &dpos, &combination_value, eye, |
| 1100 | heye, &combination_vp); |
| 1101 | heye[combination_halfeye].type = HALF_EYE; |
| 1102 | |
| 1103 | if (result) { |
| 1104 | if (combination_attack |
| 1105 | && min_eyes(value) > min_eyes(&combination_value)) { |
| 1106 | /* FIXME: I'm not sure we can ever get here. */ |
| 1107 | for (k = 0; k < combination_vp.num_attacks; k++) { |
| 1108 | if (combination_vp.attacks[k] == combination_attack) { |
| 1109 | value->a = combination_value.a; |
| 1110 | value->b = combination_value.b; |
| 1111 | *attack_point = apos; |
| 1112 | best_vp->num_attacks = 1; |
| 1113 | best_vp->attacks[0] = combination_attack; |
| 1114 | break; |
| 1115 | } |
| 1116 | } |
| 1117 | } |
| 1118 | |
| 1119 | if (combination_defense |
| 1120 | && max_eyes(value) < max_eyes(&combination_value)) { |
| 1121 | /* Turning the half eye into a proper eye gives an improvement. |
| 1122 | * However, we can only accept this result if there is a vital |
| 1123 | * point that defends both the half eye and the whole eyespace. |
| 1124 | */ |
| 1125 | for (k = 0; k < combination_vp.num_defenses; k++) { |
| 1126 | if (combination_vp.defenses[k] == combination_defense) { |
| 1127 | value->c = combination_value.c; |
| 1128 | value->d = combination_value.d; |
| 1129 | *defense_point = dpos; |
| 1130 | best_vp->num_defenses = 1; |
| 1131 | best_vp->defenses[0] = combination_defense; |
| 1132 | break; |
| 1133 | } |
| 1134 | } |
| 1135 | } |
| 1136 | |
| 1137 | if (min_eyes(value) != max_eyes(value)) { |
| 1138 | ASSERT1(combination_attack || combination_defense, combination_halfeye); |
| 1139 | if (*attack_point == NO_MOVE) { |
| 1140 | *attack_point = combination_attack; |
| 1141 | if (*attack_point == NO_MOVE) |
| 1142 | *attack_point = combination_defense; |
| 1143 | } |
| 1144 | |
| 1145 | if (*defense_point == NO_MOVE) { |
| 1146 | *defense_point = combination_defense; |
| 1147 | if (*defense_point == NO_MOVE) |
| 1148 | *defense_point = combination_defense; |
| 1149 | } |
| 1150 | } |
| 1151 | } |
| 1152 | } |
| 1153 | |
| 1154 | /* The same with ko half eye (we cannot win two kos at once, therefore we |
| 1155 | * give up if there is more than one ko half eye). |
| 1156 | */ |
| 1157 | if (num_ko_halfeyes == 1) { |
| 1158 | int result; |
| 1159 | int apos = NO_MOVE; |
| 1160 | int dpos = NO_MOVE; |
| 1161 | struct eyevalue ko_value; |
| 1162 | |
| 1163 | heye[ko_halfeye].type = 0; |
| 1164 | result = recognize_eye(pos, &apos, &dpos, &ko_value, eye, |
| 1165 | heye, &ko_vp); |
| 1166 | heye[ko_halfeye].type = HALF_EYE; |
| 1167 | |
| 1168 | if (result && max_eyes(value) < max_eyes(&ko_value)) { |
| 1169 | /* It is worthy to win the ko. */ |
| 1170 | *value = ko_value; |
| 1171 | *attack_point = apos; |
| 1172 | *defense_point = dpos; |
| 1173 | best_vp = &ko_vp; |
| 1174 | } |
| 1175 | } |
| 1176 | |
| 1177 | if (add_moves) { |
| 1178 | struct vital_eye_points *vital; |
| 1179 | if (eye_color == WHITE) |
| 1180 | vital = white_vital_points; |
| 1181 | else |
| 1182 | vital = black_vital_points; |
| 1183 | for (k = 0; k < best_vp->num_defenses && k < MAX_EYE_ATTACKS; k++) |
| 1184 | vital[pos].defense_points[k] = best_vp->defenses[k]; |
| 1185 | for (k = 0; k < best_vp->num_attacks && k < MAX_EYE_ATTACKS; k++) |
| 1186 | vital[pos].attack_points[k] = best_vp->attacks[k]; |
| 1187 | } |
| 1188 | |
| 1189 | return 1; |
| 1190 | } |
| 1191 | |
| 1192 | |
| 1193 | /* recognize_eye(pos, *attack_point, *defense_point, *max, *min, eye_data, |
| 1194 | * half_eye_data, color, vp), where pos is the origin of an eyespace, returns |
| 1195 | * owner of eye (his color) if there is a pattern in eyes.db matching the |
| 1196 | * eyespace, or 0 if no match is found. If there is a key point for attack, |
| 1197 | * (*attack_point) is set to its location, or NO_MOVE if there is none. |
| 1198 | * Similarly (*defense_point) is the location of a vital defense point. |
| 1199 | * *value is set according to the pattern found. Vital attack/defense points |
| 1200 | * exist if and only if min_eyes(value) != max_eyes(value). |
| 1201 | */ |
| 1202 | |
| 1203 | static int |
| 1204 | recognize_eye(int pos, int *attack_point, int *defense_point, |
| 1205 | struct eyevalue *value, |
| 1206 | struct eye_data eye[BOARDMAX], |
| 1207 | struct half_eye_data heye[BOARDMAX], |
| 1208 | struct vital_points *vp) |
| 1209 | { |
| 1210 | int pos2; |
| 1211 | int eye_color; |
| 1212 | int eye_size = 0; |
| 1213 | int num_marginals = 0; |
| 1214 | int vpos[MAXEYE]; |
| 1215 | signed char marginal[MAXEYE], edge[MAXEYE], neighbors[MAXEYE]; |
| 1216 | int graph; |
| 1217 | int map[MAXEYE]; |
| 1218 | int best_score; |
| 1219 | int r; |
| 1220 | |
| 1221 | gg_assert(attack_point != NULL); |
| 1222 | gg_assert(defense_point != NULL); |
| 1223 | |
| 1224 | /* Set `eye_color' to the owner of the eye. */ |
| 1225 | eye_color = eye[pos].color; |
| 1226 | |
| 1227 | if (eye[pos].esize-eye[pos].msize > 8) |
| 1228 | return 0; |
| 1229 | |
| 1230 | if (eye[pos].msize > MAXEYE) |
| 1231 | return 0; |
| 1232 | |
| 1233 | /* Create list of eye vertices */ |
| 1234 | for (pos2 = BOARDMIN; pos2 < BOARDMAX; pos2++) { |
| 1235 | if (!ON_BOARD(pos2)) |
| 1236 | continue; |
| 1237 | if (eye[pos2].origin == pos) { |
| 1238 | vpos[eye_size] = pos2; |
| 1239 | marginal[eye_size] = eye[pos2].marginal; |
| 1240 | if (marginal[eye_size]) |
| 1241 | num_marginals++; |
| 1242 | neighbors[eye_size] = eye[pos2].neighbors; |
| 1243 | if (0) { |
| 1244 | if (marginal[eye_size]) |
| 1245 | TRACE("(%1m)", vpos[eye_size]); |
| 1246 | else |
| 1247 | TRACE(" %1m ", vpos[eye_size]); |
| 1248 | TRACE("\n"); |
| 1249 | } |
| 1250 | |
| 1251 | if (is_corner_vertex(pos2)) |
| 1252 | edge[eye_size] = 2; |
| 1253 | else if (is_edge_vertex(pos2)) |
| 1254 | edge[eye_size] = 1; |
| 1255 | else |
| 1256 | edge[eye_size] = 0; |
| 1257 | |
| 1258 | if (is_halfeye(heye, pos2)) { |
| 1259 | neighbors[eye_size]++; /* Increase neighbors of half eye. */ |
| 1260 | eye_size++; |
| 1261 | /* Use a virtual marginal vertex for mapping purposes. We set it |
| 1262 | * to be at NO_MOVE so it won't accidentally count as a |
| 1263 | * neighbor for another vertex. Note that the half eye precedes |
| 1264 | * the virtual marginal vertex in the list. |
| 1265 | */ |
| 1266 | vpos[eye_size] = NO_MOVE; |
| 1267 | marginal[eye_size] = 1; |
| 1268 | num_marginals++; |
| 1269 | edge[eye_size] = 0; |
| 1270 | neighbors[eye_size] = 1; |
| 1271 | } |
| 1272 | |
| 1273 | eye_size++; |
| 1274 | } |
| 1275 | } |
| 1276 | |
| 1277 | /* We attempt to construct a map from the graph to the eyespace |
| 1278 | * preserving the adjacency structure. If this can be done, we've |
| 1279 | * identified the eyeshape. |
| 1280 | */ |
| 1281 | |
| 1282 | for (graph = 0; graphs[graph].vertex != NULL; graph++) { |
| 1283 | int q; |
| 1284 | |
| 1285 | if (graphs[graph].esize != eye_size |
| 1286 | || graphs[graph].msize != num_marginals) |
| 1287 | continue; |
| 1288 | |
| 1289 | reset_map(eye_size); |
| 1290 | q = 0; |
| 1291 | first_map(&map[0]); |
| 1292 | |
| 1293 | while (1) { |
| 1294 | struct eye_vertex *gv = &graphs[graph].vertex[q]; |
| 1295 | int mv = map[q]; |
| 1296 | int ok = 1; |
| 1297 | |
| 1298 | if (0) |
| 1299 | TRACE("q=%d: %d %d %d %d %d %d\n", |
| 1300 | q, map[0], map[1], map[2], map[3], map[4], map[5]); |
| 1301 | |
| 1302 | if (neighbors[mv] != gv->neighbors |
| 1303 | || marginal[mv] != gv->marginal |
| 1304 | || edge[mv] < gv->edge) |
| 1305 | ok = 0; |
| 1306 | |
| 1307 | if (ok) { |
| 1308 | if (IS_STONE(board[vpos[mv]])) { |
| 1309 | if (!(gv->flags & CAN_CONTAIN_STONE)) |
| 1310 | ok = 0; |
| 1311 | } |
| 1312 | /* Virtual half eye marginals also fall here since they are off |
| 1313 | * board. |
| 1314 | */ |
| 1315 | else if (!(gv->flags & CAN_BE_EMPTY)) |
| 1316 | ok = 0; |
| 1317 | } |
| 1318 | |
| 1319 | if (ok) { |
| 1320 | int k; |
| 1321 | |
| 1322 | for (k = 0; k < gv->neighbors; k++) { |
| 1323 | if (gv->n[k] < q) { |
| 1324 | int mn = map[gv->n[k]]; |
| 1325 | |
| 1326 | /* Two eye vertices are neighbours if they are adjacent on the |
| 1327 | * board or one of them is a half eye and the other is its |
| 1328 | * virtual marginal vertex (and follows it in vpos[] array). |
| 1329 | */ |
| 1330 | if (vpos[mv] != SOUTH(vpos[mn]) |
| 1331 | && vpos[mv] != WEST(vpos[mn]) |
| 1332 | && vpos[mv] != NORTH(vpos[mn]) |
| 1333 | && vpos[mv] != EAST(vpos[mn]) |
| 1334 | && (mv != mn - 1 |
| 1335 | || vpos[mv] == NO_MOVE |
| 1336 | || heye[vpos[mv]].type != HALF_EYE) |
| 1337 | && (mn != mv - 1 |
| 1338 | || vpos[mn] == NO_MOVE |
| 1339 | || heye[vpos[mn]].type != HALF_EYE)) { |
| 1340 | ok = 0; |
| 1341 | break; |
| 1342 | } |
| 1343 | } |
| 1344 | } |
| 1345 | } |
| 1346 | |
| 1347 | if (!ok) { |
| 1348 | if (!next_map(&q, map)) |
| 1349 | break; |
| 1350 | |
| 1351 | if (0) |
| 1352 | gprintf(" q=%d, esize=%d: %d %d %d %d %d\n", |
| 1353 | q, eye_size, |
| 1354 | map[0], map[1], map[2], map[3], map[4]); |
| 1355 | } |
| 1356 | else { |
| 1357 | q++; |
| 1358 | if (q == eye_size) |
| 1359 | break; /* A match! */ |
| 1360 | |
| 1361 | first_map(&map[q]); |
| 1362 | } |
| 1363 | } |
| 1364 | |
| 1365 | if (q == eye_size) { |
| 1366 | /* We have found a match! Now sort out the vital moves. */ |
| 1367 | *value = graphs[graph].value; |
| 1368 | vp->num_attacks = 0; |
| 1369 | vp->num_defenses = 0; |
| 1370 | |
| 1371 | if (eye_move_urgency(value) > 0) { |
| 1372 | /* Collect all attack and defense points in the pattern. */ |
| 1373 | int k; |
| 1374 | |
| 1375 | for (k = 0; k < eye_size; k++) { |
| 1376 | struct eye_vertex *ev = &graphs[graph].vertex[k]; |
| 1377 | |
| 1378 | if (ev->flags & EYE_ATTACK_POINT) { |
| 1379 | /* Check for a marginal vertex matching a half eye virtual |
| 1380 | * marginal. This is the case if a half eye preceeds the |
| 1381 | * current vertex in the list. |
| 1382 | */ |
| 1383 | if (ev->marginal |
| 1384 | && map[k] > 0 |
| 1385 | && vpos[map[k] - 1] != NO_MOVE |
| 1386 | && is_halfeye(heye, vpos[map[k] - 1])) { |
| 1387 | /* Add all diagonals as vital. */ |
| 1388 | int ix; |
| 1389 | struct half_eye_data *he = &heye[vpos[map[k] - 1]]; |
| 1390 | |
| 1391 | for (ix = 0; ix < he->num_attacks; ix++) |
| 1392 | vp->attacks[vp->num_attacks++] = he->attack_point[ix]; |
| 1393 | } |
| 1394 | else |
| 1395 | vp->attacks[vp->num_attacks++] = vpos[map[k]]; |
| 1396 | } |
| 1397 | |
| 1398 | if (ev->flags & EYE_DEFENSE_POINT) { |
| 1399 | /* Check for a half eye virtual marginal vertex. */ |
| 1400 | if (ev->marginal |
| 1401 | && map[k] > 0 |
| 1402 | && vpos[map[k] - 1] != NO_MOVE |
| 1403 | && is_halfeye(heye, vpos[map[k] - 1])) { |
| 1404 | /* Add all diagonals as vital. */ |
| 1405 | int ix; |
| 1406 | struct half_eye_data *he = &heye[vpos[map[k] - 1]]; |
| 1407 | |
| 1408 | for (ix = 0; ix < he->num_defenses; ix++) |
| 1409 | vp->defenses[vp->num_defenses++] = he->defense_point[ix]; |
| 1410 | } |
| 1411 | else |
| 1412 | vp->defenses[vp->num_defenses++] = vpos[map[k]]; |
| 1413 | } |
| 1414 | } |
| 1415 | |
| 1416 | gg_assert(vp->num_attacks > 0 && vp->num_defenses > 0); |
| 1417 | |
| 1418 | /* We now have all vital attack and defense points listed but |
| 1419 | * we are also expected to single out of one of each to return |
| 1420 | * in *attack_point and *defense_point. Since sometimes those |
| 1421 | * are the only vital points considered, we want to choose the |
| 1422 | * best ones, in the sense that they minimize the risk for |
| 1423 | * error in the eye space analysis. |
| 1424 | * |
| 1425 | * One example is this position |
| 1426 | * |
| 1427 | * |..XXXX |
| 1428 | * |XXX..X |
| 1429 | * |..!O.X |
| 1430 | * |OO.O.X |
| 1431 | * |.O.!XX |
| 1432 | * +------ |
| 1433 | * |
| 1434 | * where O has an eyespace of the !..! type. The graph |
| 1435 | * matching finds that both marginal vertices are vital points |
| 1436 | * but here the one at 3-3 fails to defend. (For attack both |
| 1437 | * points work but the 3-3 one is still worse since it leaves |
| 1438 | * a ko threat.) |
| 1439 | * |
| 1440 | * In order to differentiate between the marginal points we |
| 1441 | * count the number of straight and diagonal neighbors within |
| 1442 | * the eye space. In the example above both have one straight |
| 1443 | * neighbor each but the edge margin wins because it also has |
| 1444 | * a diagonal margin. |
| 1445 | */ |
| 1446 | |
| 1447 | best_score = -10; |
| 1448 | for (k = 0; k < vp->num_attacks; k++) { |
| 1449 | int apos = vp->attacks[k]; |
| 1450 | int score = 0; |
| 1451 | for (r = 0; r < 8; r++) |
| 1452 | if (ON_BOARD(apos + delta[r]) |
| 1453 | && eye[apos + delta[r]].color == eye[pos].color |
| 1454 | && !eye[apos + delta[r]].marginal) { |
| 1455 | score++; |
| 1456 | if (r < 4) { |
| 1457 | score++; |
| 1458 | if (board[apos + delta[r]] != EMPTY) |
| 1459 | score++; |
| 1460 | } |
| 1461 | } |
| 1462 | |
| 1463 | /* If a vital point is not adjacent to any point in the eye |
| 1464 | * space, it must be a move to capture or defend a string |
| 1465 | * related to a halfeye, e.g. the move * in this position, |
| 1466 | * |
| 1467 | * ......| |
| 1468 | * .XXXX.| |
| 1469 | * .X.O..| |
| 1470 | * .XO.OO| |
| 1471 | * .*XO..| |
| 1472 | * ------+ |
| 1473 | * |
| 1474 | * Playing this is probably a good idea. |
| 1475 | */ |
| 1476 | if (score == 0) |
| 1477 | score += 2; |
| 1478 | |
| 1479 | if (0) |
| 1480 | gprintf("attack point %1m score %d\n", apos, score); |
| 1481 | |
| 1482 | if (score > best_score) { |
| 1483 | *attack_point = apos; |
| 1484 | best_score = score; |
| 1485 | } |
| 1486 | } |
| 1487 | |
| 1488 | best_score = -10; |
| 1489 | for (k = 0; k < vp->num_defenses; k++) { |
| 1490 | int dpos = vp->defenses[k]; |
| 1491 | int score = 0; |
| 1492 | for (r = 0; r < 8; r++) |
| 1493 | if (ON_BOARD(dpos + delta[r]) |
| 1494 | && eye[dpos + delta[r]].color == eye[pos].color |
| 1495 | && !eye[dpos + delta[r]].marginal) { |
| 1496 | score++; |
| 1497 | if (r < 4) { |
| 1498 | score++; |
| 1499 | if (board[dpos + delta[r]] != EMPTY) |
| 1500 | score++; |
| 1501 | } |
| 1502 | } |
| 1503 | |
| 1504 | /* If possible, choose a non-sacrificial defense point. |
| 1505 | * Compare white T8 and T6 in lazarus:21. |
| 1506 | */ |
| 1507 | if (safe_move(dpos, eye_color) != WIN) |
| 1508 | score -= 5; |
| 1509 | |
| 1510 | /* See comment to the same code for attack points. */ |
| 1511 | if (score == 0) |
| 1512 | score += 2; |
| 1513 | |
| 1514 | if (0) |
| 1515 | gprintf("defense point %1m score %d\n", dpos, score); |
| 1516 | |
| 1517 | if (score > best_score) { |
| 1518 | *defense_point = dpos; |
| 1519 | best_score = score; |
| 1520 | } |
| 1521 | } |
| 1522 | |
| 1523 | DEBUG(DEBUG_EYES, " vital points: %1m (attack) %1m (defense)\n", |
| 1524 | *attack_point, *defense_point); |
| 1525 | DEBUG(DEBUG_EYES, " pattern matched: %d\n", graphs[graph].patnum); |
| 1526 | |
| 1527 | } |
| 1528 | TRACE("eye space at %1m of type %d\n", pos, graphs[graph].patnum); |
| 1529 | |
| 1530 | return eye_color; |
| 1531 | } |
| 1532 | } |
| 1533 | |
| 1534 | return 0; |
| 1535 | } |
| 1536 | |
| 1537 | |
| 1538 | /* a MAP is a map of the integers 0,1,2, ... ,q into |
| 1539 | * 0,1, ... , esize-1 where q < esize. This determines a |
| 1540 | * bijection of the first q+1 elements of the graph into the |
| 1541 | * eyespace. The following three functions work with maps. |
| 1542 | */ |
| 1543 | |
| 1544 | /* Reset internal data structure used by first_map() and |
| 1545 | * next_map() functions. |
| 1546 | */ |
| 1547 | static void |
| 1548 | reset_map(int size) |
| 1549 | { |
| 1550 | map_size = size; |
| 1551 | memset(used_index, 0, size * sizeof(used_index[0])); |
| 1552 | } |
| 1553 | |
| 1554 | |
| 1555 | /* The function first_map finds the smallest valid |
| 1556 | * value of a map element. |
| 1557 | */ |
| 1558 | static void |
| 1559 | first_map(int *map_value) |
| 1560 | { |
| 1561 | int k = 0; |
| 1562 | |
| 1563 | while (used_index[k]) |
| 1564 | k++; |
| 1565 | |
| 1566 | used_index[k] = 1; |
| 1567 | *map_value = k; |
| 1568 | } |
| 1569 | |
| 1570 | |
| 1571 | /* The function next_map produces the next map in lexicographical |
| 1572 | * order. If no next map can be found, q is decremented, then we |
| 1573 | * try again. If the entire map is lexicographically last, the |
| 1574 | * function returns false. |
| 1575 | */ |
| 1576 | static int |
| 1577 | next_map(int *q, int map[MAXEYE]) |
| 1578 | { |
| 1579 | int k; |
| 1580 | |
| 1581 | do { |
| 1582 | used_index[map[*q]] = 0; |
| 1583 | for (k = map[*q]; ++k < map_size;) { |
| 1584 | if (!used_index[k]) { |
| 1585 | used_index[k] = 1; |
| 1586 | map[*q] = k; |
| 1587 | return 1; |
| 1588 | } |
| 1589 | } |
| 1590 | |
| 1591 | (*q)--; |
| 1592 | } while (*q >= 0); |
| 1593 | |
| 1594 | return 0; |
| 1595 | } |
| 1596 | |
| 1597 | |
| 1598 | /* add_false_eye() turns a proper eyespace into a margin. */ |
| 1599 | |
| 1600 | static void |
| 1601 | add_false_eye(int pos, struct eye_data eye[BOARDMAX], |
| 1602 | struct half_eye_data heye[BOARDMAX]) |
| 1603 | { |
| 1604 | int k; |
| 1605 | ASSERT1(heye[pos].type == FALSE_EYE, pos); |
| 1606 | DEBUG(DEBUG_EYES, "false eye found at %1m\n", pos); |
| 1607 | |
| 1608 | if (eye[pos].color == GRAY || eye[pos].marginal != 0) |
| 1609 | return; |
| 1610 | |
| 1611 | eye[pos].marginal = 1; |
| 1612 | eye[eye[pos].origin].msize++; |
| 1613 | for (k = 0; k < 4; k++) |
| 1614 | if (ON_BOARD(pos + delta[k]) |
| 1615 | && eye[pos + delta[k]].origin == eye[pos].origin) |
| 1616 | eye[pos + delta[k]].marginal_neighbors++; |
| 1617 | propagate_eye(eye[pos].origin, eye); |
| 1618 | } |
| 1619 | |
| 1620 | |
| 1621 | /* These functions are used from constraints to identify eye spaces, |
| 1622 | * primarily for late endgame moves. |
| 1623 | */ |
| 1624 | int |
| 1625 | is_eye_space(int pos) |
| 1626 | { |
| 1627 | return (white_eye[pos].color == WHITE |
| 1628 | || black_eye[pos].color == BLACK); |
| 1629 | } |
| 1630 | |
| 1631 | int |
| 1632 | is_proper_eye_space(int pos) |
| 1633 | { |
| 1634 | return ((white_eye[pos].color == WHITE && !white_eye[pos].marginal) |
| 1635 | || (black_eye[pos].color == BLACK && !black_eye[pos].marginal)); |
| 1636 | } |
| 1637 | |
| 1638 | /* Return the maximum number of eyes that can be obtained from the |
| 1639 | * eyespace at (i, j). This is most useful in order to determine |
| 1640 | * whether the eyespace can be assumed to produce any territory at |
| 1641 | * all. |
| 1642 | */ |
| 1643 | int |
| 1644 | max_eye_value(int pos) |
| 1645 | { |
| 1646 | int max_white = 0; |
| 1647 | int max_black = 0; |
| 1648 | |
| 1649 | if (white_eye[pos].color == WHITE) |
| 1650 | max_white = max_eyes(&white_eye[pos].value); |
| 1651 | |
| 1652 | if (black_eye[pos].color == BLACK) |
| 1653 | max_black = max_eyes(&black_eye[pos].value); |
| 1654 | |
| 1655 | return gg_max(max_white, max_black); |
| 1656 | } |
| 1657 | |
| 1658 | int |
| 1659 | is_marginal_eye_space(int pos) |
| 1660 | { |
| 1661 | return (white_eye[pos].marginal || black_eye[pos].marginal); |
| 1662 | } |
| 1663 | |
| 1664 | int |
| 1665 | is_halfeye(struct half_eye_data heye[BOARDMAX], int pos) |
| 1666 | { |
| 1667 | return heye[pos].type == HALF_EYE; |
| 1668 | } |
| 1669 | |
| 1670 | int |
| 1671 | is_false_eye(struct half_eye_data heye[BOARDMAX], int pos) |
| 1672 | { |
| 1673 | return heye[pos].type == FALSE_EYE; |
| 1674 | } |
| 1675 | |
| 1676 | |
| 1677 | /* Find topological half eyes and false eyes by analyzing the |
| 1678 | * diagonal intersections, as described in the Texinfo |
| 1679 | * documentation (Eyes/Eye Topology). |
| 1680 | */ |
| 1681 | void |
| 1682 | find_half_and_false_eyes(int color, struct eye_data eye[BOARDMAX], |
| 1683 | struct half_eye_data heye[BOARDMAX], |
| 1684 | int find_mask[BOARDMAX]) |
| 1685 | { |
| 1686 | int eye_color = color; |
| 1687 | int pos; |
| 1688 | float sum; |
| 1689 | |
| 1690 | for (pos = BOARDMIN; pos < BOARDMAX; pos++) { |
| 1691 | /* skip eyespaces which owl doesn't want to be searched */ |
| 1692 | if (!ON_BOARD(pos) || (find_mask && find_mask[eye[pos].origin] <= 1)) |
| 1693 | continue; |
| 1694 | |
| 1695 | /* skip every vertex which can't be a false or half eye */ |
| 1696 | if (eye[pos].color != eye_color |
| 1697 | || eye[pos].marginal |
| 1698 | || eye[pos].neighbors > 1) |
| 1699 | continue; |
| 1700 | |
| 1701 | sum = topological_eye(pos, color, eye, heye); |
| 1702 | if (sum >= 4.0) { |
| 1703 | /* false eye */ |
| 1704 | heye[pos].type = FALSE_EYE; |
| 1705 | if (eye[pos].esize == 1 |
| 1706 | || is_legal(pos, OTHER_COLOR(color)) |
| 1707 | || board[pos] == OTHER_COLOR(color)) |
| 1708 | add_false_eye(pos, eye, heye); |
| 1709 | } |
| 1710 | else if (sum > 2.0) { |
| 1711 | /* half eye */ |
| 1712 | heye[pos].type = HALF_EYE; |
| 1713 | ASSERT1(heye[pos].num_attacks > 0, pos); |
| 1714 | ASSERT_ON_BOARD1(heye[pos].attack_point[0]); |
| 1715 | ASSERT1(heye[pos].num_defenses > 0, pos); |
| 1716 | ASSERT_ON_BOARD1(heye[pos].defense_point[0]); |
| 1717 | } |
| 1718 | } |
| 1719 | } |
| 1720 | |
| 1721 | |
| 1722 | /* See Texinfo documentation (Eyes:Eye Topology). Returns: |
| 1723 | * - 2 or less if (pos) is a proper eye for (color); |
| 1724 | * - between 2 and 3 if the eye can be made false only by ko |
| 1725 | * - 3 if (pos) is a half eye; |
| 1726 | * - between 3 and 4 if the eye can be made real only by ko |
| 1727 | * - 4 or more if (pos) is a false eye. |
| 1728 | * |
| 1729 | * Attack and defense points for control of the diagonals are stored |
| 1730 | * in the heye[] array. |
| 1731 | * |
| 1732 | * my_eye is the eye space information with respect to (color). |
| 1733 | */ |
| 1734 | |
| 1735 | static float |
| 1736 | topological_eye(int pos, int color, |
| 1737 | struct eye_data my_eye[BOARDMAX], |
| 1738 | struct half_eye_data heye[BOARDMAX]) |
| 1739 | { |
| 1740 | float sum = 0.0; |
| 1741 | float val; |
| 1742 | int num_attacks = 0; |
| 1743 | int num_defenses = 0; |
| 1744 | int attack_values[4]; |
| 1745 | int defense_values[4]; |
| 1746 | int k; |
| 1747 | int r; |
| 1748 | int attack_point; |
| 1749 | int defense_point; |
| 1750 | int attack_value; |
| 1751 | int defense_value; |
| 1752 | |
| 1753 | memset(attack_values, 0, sizeof(attack_values)); |
| 1754 | memset(defense_values, 0, sizeof(defense_values)); |
| 1755 | |
| 1756 | /* Loop over the diagonal directions. */ |
| 1757 | for (k = 4; k < 8; k++) { |
| 1758 | int diag = pos + delta[k]; |
| 1759 | val = evaluate_diagonal_intersection(I(pos) + deltai[k], |
| 1760 | J(pos) + deltaj[k], color, |
| 1761 | &attack_point, &defense_point, |
| 1762 | my_eye); |
| 1763 | |
| 1764 | /* |
| 1765 | * Eyespaces with cutting points are problematic. In this position |
| 1766 | * |
| 1767 | * .....XXXXX |
| 1768 | * XXXXX.OO.X |
| 1769 | * X.OOOO.O.X |
| 1770 | * X.O.XXXO.X |
| 1771 | * ---------- |
| 1772 | * |
| 1773 | * the eyespace will be .XXX. which evaluates to two eyes (seki) |
| 1774 | * unless countermeasures are taken. |
| 1775 | * |
| 1776 | * This can be worked around in the topological analysis by |
| 1777 | * sometimes setting the diagonal value to 2.0 for vertices inside |
| 1778 | * the eyespace which are occupied by opponent stones. More |
| 1779 | * precisely all of the following conditions must hold: |
| 1780 | * |
| 1781 | * a) The value is not already 2.0. |
| 1782 | * a) The (potential) eyepoint is empty. |
| 1783 | * b) The diagonal is occupied by an opponent string, |
| 1784 | * c) which is also adjacent to the (potential) eye and |
| 1785 | * d) at least three stones long. |
| 1786 | * e) The (potential) eye is not on the edge (to steer clear of all the |
| 1787 | * hairy cases that are handled by eyes.db anyway). |
| 1788 | * f) At least two own strings are adjacent to the (potential) eye. |
| 1789 | * g) At least one of the own strings adjacent to the (potential) eye has |
| 1790 | * only one liberty which is an eye space and not decided false, yet. |
| 1791 | * |
| 1792 | * With this revision the eyespace above becomes .XXXh or |
| 1793 | * equivalently .XXX.! which is almost evaluated correctly, eye |
| 1794 | * value 0122 instead of the correct 1122. Compared to the |
| 1795 | * previous value 2222 it's a major improvement. |
| 1796 | * |
| 1797 | * FIXME: This approach has a number of shortcomings. |
| 1798 | * |
| 1799 | * 1. d) is kind of arbitrary and there may be exceptional |
| 1800 | * cases. |
| 1801 | * |
| 1802 | * 2. This diagonal value modification should not apply to |
| 1803 | * two diagonals of the same strings inside the eyespace. |
| 1804 | * E.g. if we have a partial eyespace looking like |
| 1805 | * |
| 1806 | * .OOO. |
| 1807 | * OO.OO |
| 1808 | * OXXXO |
| 1809 | * |
| 1810 | * it doesn't make sense to mark the middle vertex as a |
| 1811 | * false eye. Possibly this doesn't make any difference |
| 1812 | * in practice but it's at the very least confusing. |
| 1813 | * |
| 1814 | * 3. Actually it doesn't make sense to mark vertices as |
| 1815 | * false otherwise either due to these revisions (half |
| 1816 | * eyes make good sense though) as can be seen if a |
| 1817 | * stone is added to the initial diagram, |
| 1818 | * |
| 1819 | * .....XXXXX |
| 1820 | * XXXXXXOO.X |
| 1821 | * X.OOOO.O.X |
| 1822 | * X.O.XXXO.X |
| 1823 | * ---------- |
| 1824 | * |
| 1825 | * Now the eyespace instead becomes .XXX! which has the |
| 1826 | * eye value 0011 but if X tries to attack the eye O |
| 1827 | * suddenly gets two solid eyes! |
| 1828 | * |
| 1829 | * The correct analysis would be to remove the vertex |
| 1830 | * from the eyespace rather than turning it into a false |
| 1831 | * eye. Then we would have the eyespace .XXX which is |
| 1832 | * correctly evaluated to one eye (eye value 1112). |
| 1833 | * |
| 1834 | * The problem with this is that removing eye points is |
| 1835 | * messy. It can surely be done but currently there is |
| 1836 | * no support in the code for doing that. It has existed |
| 1837 | * at an earlier time but was removed because the |
| 1838 | * implementation was not robust enough and there was no |
| 1839 | * longer any apparent need for it. To correct this |
| 1840 | * problem is sufficient reason to reimplement that |
| 1841 | * functionality. |
| 1842 | * |
| 1843 | * 4. The test of condition g) has a result which |
| 1844 | * potentially depends on the ordering of the eyespaces |
| 1845 | * and thus presumably on the orientation of the board. |
| 1846 | * It might make more sense to examine whether the |
| 1847 | * string neighbors more than one empty vertex in the |
| 1848 | * same eyespace. |
| 1849 | */ |
| 1850 | if (val < 2.0 && board[pos] == EMPTY && board[diag] == OTHER_COLOR(color) |
| 1851 | && !is_edge_vertex(pos) && neighbor_of_string(pos, diag) |
| 1852 | && countstones(diag) >= 3) { |
| 1853 | int strings[3]; |
| 1854 | int string_count; |
| 1855 | int s; |
| 1856 | string_count = 0; |
| 1857 | for (r = 0; r < 4; r++) { |
| 1858 | int str; |
| 1859 | str = pos + delta[r]; |
| 1860 | |
| 1861 | if (board[str] != color) |
| 1862 | continue; |
| 1863 | |
| 1864 | ASSERT1(string_count < 3, pos); |
| 1865 | for (s = 0; s < string_count; s++) |
| 1866 | if (same_string(str, strings[s])) |
| 1867 | break; |
| 1868 | if (s != string_count) |
| 1869 | continue; |
| 1870 | |
| 1871 | strings[string_count++] = str; |
| 1872 | } |
| 1873 | if (string_count > 1) { |
| 1874 | for (s = 0; s < string_count; s++) { |
| 1875 | int libs[MAX_LIBERTIES]; |
| 1876 | int adj_eye_count; |
| 1877 | int lib_count; |
| 1878 | adj_eye_count = 0; |
| 1879 | lib_count = findlib(strings[s], MAX_LIBERTIES, libs); |
| 1880 | if (lib_count > MAX_LIBERTIES) |
| 1881 | continue; |
| 1882 | |
| 1883 | for (r = 0; r < lib_count && adj_eye_count < 2; r++) |
| 1884 | if (my_eye[libs[r]].color == OTHER_COLOR(color) |
| 1885 | && !my_eye[libs[r]].marginal) |
| 1886 | adj_eye_count++; |
| 1887 | if (adj_eye_count < 2) { |
| 1888 | val = 2.0; |
| 1889 | break; |
| 1890 | } |
| 1891 | } |
| 1892 | } |
| 1893 | } |
| 1894 | |
| 1895 | sum += val; |
| 1896 | |
| 1897 | if (val > 0.0 && val < 2.0) { |
| 1898 | /* Diagonals off the edge has value 1.0 but no attack or defense |
| 1899 | * point. |
| 1900 | */ |
| 1901 | if (attack_point != NO_MOVE && defense_point != NO_MOVE) { |
| 1902 | ASSERT_ON_BOARD1(attack_point); |
| 1903 | ASSERT_ON_BOARD1(defense_point); |
| 1904 | /* Store these in sorted (descending) order. We remap val |
| 1905 | * differently for attack and defense points according to: |
| 1906 | * |
| 1907 | * val attack_value defense_value |
| 1908 | * --- ------------ ------------- |
| 1909 | * 1.0 3 3 |
| 1910 | * <1.0 2 1 |
| 1911 | * >1.0 1 2 |
| 1912 | * |
| 1913 | * This means that we primarily want to take control of |
| 1914 | * diagonals without ko and secondarily of diagonals we can |
| 1915 | * take unconditionally but not the opponent. |
| 1916 | */ |
| 1917 | if (val == 1.0) { |
| 1918 | attack_value = 3; |
| 1919 | defense_value = 3; |
| 1920 | } |
| 1921 | else if (val < 1.0) { |
| 1922 | attack_value = 2; |
| 1923 | defense_value = 1; |
| 1924 | } |
| 1925 | else { |
| 1926 | attack_value = 1; |
| 1927 | defense_value = 2; |
| 1928 | } |
| 1929 | |
| 1930 | for (r = 0; r < 4; r++) { |
| 1931 | if (attack_values[r] < attack_value) { |
| 1932 | int tmp_value = attack_values[r]; |
| 1933 | int tmp_point; |
| 1934 | if (tmp_value) |
| 1935 | tmp_point = heye[pos].attack_point[r]; |
| 1936 | else |
| 1937 | tmp_point = 0; |
| 1938 | attack_values[r] = attack_value; |
| 1939 | heye[pos].attack_point[r] = attack_point; |
| 1940 | attack_value = tmp_value; |
| 1941 | attack_point = tmp_point; |
| 1942 | } |
| 1943 | |
| 1944 | if (defense_values[r] < defense_value) { |
| 1945 | int tmp_value = defense_values[r]; |
| 1946 | int tmp_point; |
| 1947 | if (tmp_value) |
| 1948 | tmp_point = heye[pos].defense_point[r]; |
| 1949 | else |
| 1950 | tmp_point = 0; |
| 1951 | defense_values[r] = defense_value; |
| 1952 | heye[pos].defense_point[r] = defense_point; |
| 1953 | defense_value = tmp_value; |
| 1954 | defense_point = tmp_point; |
| 1955 | } |
| 1956 | } |
| 1957 | |
| 1958 | num_attacks++; |
| 1959 | num_defenses++; |
| 1960 | } |
| 1961 | } |
| 1962 | } |
| 1963 | |
| 1964 | /* Remove attacks and defenses with smaller value than the best |
| 1965 | * ones. (These might be useful to save as well, but not unless we |
| 1966 | * also store the attack/defense values in the half_eye_data.) |
| 1967 | */ |
| 1968 | for (r = 0; r < num_attacks; r++) { |
| 1969 | if (attack_values[r] < attack_values[0]) { |
| 1970 | num_attacks = r; |
| 1971 | break; |
| 1972 | } |
| 1973 | } |
| 1974 | |
| 1975 | for (r = 0; r < num_defenses; r++) { |
| 1976 | if (defense_values[r] < defense_values[0]) { |
| 1977 | num_defenses = r; |
| 1978 | break; |
| 1979 | } |
| 1980 | } |
| 1981 | |
| 1982 | heye[pos].num_attacks = num_attacks; |
| 1983 | heye[pos].num_defenses = num_defenses; |
| 1984 | heye[pos].value = sum; |
| 1985 | |
| 1986 | return sum; |
| 1987 | } |
| 1988 | |
| 1989 | |
| 1990 | |
| 1991 | /* Evaluate an intersection (m, n) which is diagonal to an eye space, |
| 1992 | * as described in the Texinfo documentation (Eyes/Eye Topology). |
| 1993 | * |
| 1994 | * Returns: |
| 1995 | * |
| 1996 | * 0 if both coordinates are off the board |
| 1997 | * 1 if one coordinate is off the board |
| 1998 | * |
| 1999 | * 0 if (color) has control over the vertex |
| 2000 | * a if (color) can take control over the vertex unconditionally and |
| 2001 | * the opponent can take control by winning a ko. |
| 2002 | * 1 if both (color) and the opponent can take control of the vertex |
| 2003 | * unconditionally |
| 2004 | * b if (color) can take control over the vertex by winning a ko and |
| 2005 | * the opponent can take control unconditionally. |
| 2006 | * 2 if the opponent has control over the vertex |
| 2007 | * |
| 2008 | * The values a and b are discussed in the documentation. We are |
| 2009 | * currently using a = 0.75 and b = 1.25. |
| 2010 | * |
| 2011 | * Notice that it's necessary to pass the coordinates separately |
| 2012 | * instead of as a 1D coordinate. The reason is that the 1D mapping |
| 2013 | * can't uniquely identify "off the corner" points. |
| 2014 | * |
| 2015 | * my_eye has to be the eye_data with respect to color. |
| 2016 | */ |
| 2017 | static float |
| 2018 | evaluate_diagonal_intersection(int m, int n, int color, |
| 2019 | int *attack_point, int *defense_point, |
| 2020 | struct eye_data my_eye[BOARDMAX]) |
| 2021 | { |
| 2022 | float value = 0; |
| 2023 | int other = OTHER_COLOR(color); |
| 2024 | int pos = POS(m, n); |
| 2025 | int acode = 0; |
| 2026 | int apos = NO_MOVE; |
| 2027 | int dcode = 0; |
| 2028 | int dpos = NO_MOVE; |
| 2029 | int off_edge = 0; |
| 2030 | const float a = 0.75; |
| 2031 | const float b = 2 - a; |
| 2032 | |
| 2033 | *attack_point = NO_MOVE; |
| 2034 | *defense_point = NO_MOVE; |
| 2035 | |
| 2036 | /* Check whether intersection is off the board. We must do this for |
| 2037 | * each board coordinate separately because points "off the corner" |
| 2038 | * are special cases. |
| 2039 | */ |
| 2040 | if (m < 0 || m >= board_size) |
| 2041 | off_edge++; |
| 2042 | |
| 2043 | if (n < 0 || n >= board_size) |
| 2044 | off_edge++; |
| 2045 | |
| 2046 | /* Must return 0 if both coordinates out of bounds. */ |
| 2047 | if (off_edge > 0) |
| 2048 | return (float) (off_edge % 2); |
| 2049 | |
| 2050 | /* Discard points within own eyespace, unless marginal or ko point. |
| 2051 | * |
| 2052 | * Comment: For some time discardment of points within own eyespace |
| 2053 | * was contingent on this being the same eyespace as that of the |
| 2054 | * examined vertex. This caused problems, e.g. in this position, |
| 2055 | * |
| 2056 | * |........ |
| 2057 | * |XXXXX... |
| 2058 | * |OOOOX... |
| 2059 | * |aO.OX... |
| 2060 | * |OXXOX... |
| 2061 | * |.XXOX... |
| 2062 | * +-------- |
| 2063 | * |
| 2064 | * where the empty vertex at a was evaluated as a false eye and the |
| 2065 | * whole group as dead (instead of living in seki). |
| 2066 | * |
| 2067 | * The reason for the requirement of less than two marginal |
| 2068 | * neighbors is this position: |
| 2069 | * |
| 2070 | * |.XXXX... |
| 2071 | * |.OOOX... |
| 2072 | * |O..OX... |
| 2073 | * |aOO.X... |
| 2074 | * |O..XX... |
| 2075 | * |..O.X... |
| 2076 | * |.X..X... |
| 2077 | * |..XXX... |
| 2078 | * |
| 2079 | * where the empty vertex at a should not count as a solid eye. |
| 2080 | * (The eyespace diagonally below a looks like this: |
| 2081 | * .! |
| 2082 | * ! |
| 2083 | * so we can clearly see why having two marginal vertices makes a |
| 2084 | * difference.) |
| 2085 | */ |
| 2086 | if (my_eye[pos].color == color |
| 2087 | && !my_eye[pos].marginal |
| 2088 | && my_eye[pos].marginal_neighbors < 2 |
| 2089 | && !(board[pos] == EMPTY && does_capture_something(pos, other))) |
| 2090 | return 0.0; |
| 2091 | |
| 2092 | if (board[pos] == EMPTY) { |
| 2093 | int your_safety = safe_move(pos, other); |
| 2094 | |
| 2095 | apos = pos; |
| 2096 | dpos = pos; |
| 2097 | |
| 2098 | /* We should normally have a safe move, but occasionally it may |
| 2099 | * happen that it's not safe. There are complications, however, |
| 2100 | * with a position like this: |
| 2101 | * |
| 2102 | * .XXXX| |
| 2103 | * XXOO.| |
| 2104 | * XO.O.| |
| 2105 | * XXO.O| |
| 2106 | * -----+ |
| 2107 | * |
| 2108 | * Therefore we ignore our own safety if opponent's safety depends |
| 2109 | * on ko. |
| 2110 | */ |
| 2111 | if (your_safety == 0) |
| 2112 | value = 0.0; |
| 2113 | else if (your_safety != WIN) |
| 2114 | value = a; |
| 2115 | else { /* So your_safety == WIN. */ |
| 2116 | int our_safety = safe_move(pos, color); |
| 2117 | |
| 2118 | if (our_safety == 0) { |
| 2119 | int k; |
| 2120 | |
| 2121 | value = 2.0; |
| 2122 | |
| 2123 | /* This check is intended to fix a certain special case, but might |
| 2124 | * be helpful in other situations as well. Consider this position, |
| 2125 | * happened in owl reading deep enough: |
| 2126 | * |
| 2127 | * |XXXXX |
| 2128 | * |XOOXX |
| 2129 | * |O.OOX |
| 2130 | * |.OXX. |
| 2131 | * +----- |
| 2132 | * |
| 2133 | * Without this check, the corner eye is considered false, not half- |
| 2134 | * eye. Thus, owl thinks that the capture gains at most one eye and |
| 2135 | * gives up. |
| 2136 | */ |
| 2137 | for (k = 4; k < 8; k++) { |
| 2138 | int diagonal = pos + delta[k]; |
| 2139 | int lib; |
| 2140 | |
| 2141 | if (board[diagonal] == other && findlib(diagonal, 1, &lib) == 1) { |
| 2142 | if (lib != pos && does_secure(color, lib, pos)) { |
| 2143 | value = 1.0; |
| 2144 | apos = lib; |
| 2145 | break; |
| 2146 | } |
| 2147 | } |
| 2148 | } |
| 2149 | } |
| 2150 | else if (our_safety == WIN) |
| 2151 | value = 1.0; |
| 2152 | else /* our_safety depends on ko. */ |
| 2153 | value = b; |
| 2154 | } |
| 2155 | } |
| 2156 | else if (board[pos] == color) { |
| 2157 | /* This stone had better be safe, otherwise we wouldn't have an |
| 2158 | * eyespace in the first place. |
| 2159 | */ |
| 2160 | value = 0.0; |
| 2161 | } |
| 2162 | else if (board[pos] == other) { |
| 2163 | if (stackp == 0) { |
| 2164 | acode = worm[pos].attack_codes[0]; |
| 2165 | apos = worm[pos].attack_points[0]; |
| 2166 | dcode = worm[pos].defense_codes[0]; |
| 2167 | dpos = worm[pos].defense_points[0]; |
| 2168 | } |
| 2169 | else |
| 2170 | attack_and_defend(pos, &acode, &apos, &dcode, &dpos); |
| 2171 | |
| 2172 | /* Must test acode first since dcode only is reliable if acode is |
| 2173 | * non-zero. |
| 2174 | */ |
| 2175 | if (acode == 0) |
| 2176 | value = 2.0; |
| 2177 | else if (dcode == 0) |
| 2178 | value = 0.0; |
| 2179 | else if (acode == WIN && dcode == WIN) |
| 2180 | value = 1.0; |
| 2181 | else if (acode == WIN && dcode != WIN) |
| 2182 | value = a; |
| 2183 | else if (acode != WIN && dcode == WIN) |
| 2184 | value = b; |
| 2185 | else if (acode != WIN && dcode != WIN) |
| 2186 | value = 1.0; /* Both contingent on ko. Probably can't happen. */ |
| 2187 | } |
| 2188 | |
| 2189 | if (value > 0.0 && value < 2.0) { |
| 2190 | /* FIXME: |
| 2191 | * Usually there are several attack and defense moves that would |
| 2192 | * be equally valid. It's not good that we make an arbitrary |
| 2193 | * choice at this point. |
| 2194 | */ |
| 2195 | ASSERT_ON_BOARD1(apos); |
| 2196 | ASSERT_ON_BOARD1(dpos); |
| 2197 | /* Notice: |
| 2198 | * The point to ATTACK the half eye is the point which DEFENDS |
| 2199 | * the stones on the diagonal intersection and vice versa. Thus |
| 2200 | * we must switch attack and defense points here. |
| 2201 | * If the vertex is empty, dpos == apos and it doesn't matter |
| 2202 | * whether we switch. |
| 2203 | */ |
| 2204 | *attack_point = dpos; |
| 2205 | *defense_point = apos; |
| 2206 | } |
| 2207 | |
| 2208 | return value; |
| 2209 | } |
| 2210 | |
| 2211 | |
| 2212 | /* Conservative relative of topological_eye(). Essentially the same |
| 2213 | * algorithm is used, but only tactically safe opponent strings on |
| 2214 | * diagonals are considered. This may underestimate the false/half eye |
| 2215 | * status, but it should never be overestimated. |
| 2216 | */ |
| 2217 | int |
| 2218 | obvious_false_eye(int pos, int color) |
| 2219 | { |
| 2220 | int i = I(pos); |
| 2221 | int j = J(pos); |
| 2222 | int k; |
| 2223 | int diagonal_sum = 0; |
| 2224 | for (k = 4; k < 8; k++) { |
| 2225 | int di = deltai[k]; |
| 2226 | int dj = deltaj[k]; |
| 2227 | |
| 2228 | if (!ON_BOARD2(i+di, j) && !ON_BOARD2(i, j+dj)) |
| 2229 | diagonal_sum--; |
| 2230 | |
| 2231 | if (!ON_BOARD2(i+di, j+dj)) |
| 2232 | diagonal_sum++; |
| 2233 | else if (BOARD(i+di, j+dj) == OTHER_COLOR(color) |
| 2234 | && !attack(POS(i+di, j+dj), NULL)) |
| 2235 | diagonal_sum += 2; |
| 2236 | } |
| 2237 | |
| 2238 | return diagonal_sum >= 4; |
| 2239 | } |
| 2240 | |
| 2241 | |
| 2242 | /* Set the parameters into struct eyevalue as follows: |
| 2243 | a = number of eyes if attacker plays first twice |
| 2244 | b = number of eyes if attacker plays first |
| 2245 | c = number of eyes if defender plays first |
| 2246 | d =number of eyes if defender plays first twice |
| 2247 | */ |
| 2248 | |
| 2249 | void |
| 2250 | set_eyevalue(struct eyevalue *e, int a, int b, int c, int d) |
| 2251 | { |
| 2252 | e->a = a; |
| 2253 | e->b = b; |
| 2254 | e->c = c; |
| 2255 | e->d = d; |
| 2256 | } |
| 2257 | |
| 2258 | /* Number of eyes if attacker plays first twice (the threat of the first |
| 2259 | * move by attacker). |
| 2260 | */ |
| 2261 | int |
| 2262 | min_eye_threat(struct eyevalue *e) |
| 2263 | { |
| 2264 | return e->a; |
| 2265 | } |
| 2266 | |
| 2267 | /* Number of eyes if attacker plays first followed by alternating play. */ |
| 2268 | int |
| 2269 | min_eyes(struct eyevalue *e) |
| 2270 | { |
| 2271 | return e->b; |
| 2272 | } |
| 2273 | |
| 2274 | /* Number of eyes if defender plays first followed by alternating play. */ |
| 2275 | int |
| 2276 | max_eyes(struct eyevalue *e) |
| 2277 | { |
| 2278 | return e->c; |
| 2279 | } |
| 2280 | |
| 2281 | /* Number of eyes if defender plays first twice (the threat of the first |
| 2282 | * move by defender). |
| 2283 | */ |
| 2284 | int |
| 2285 | max_eye_threat(struct eyevalue *e) |
| 2286 | { |
| 2287 | return e->d; |
| 2288 | } |
| 2289 | |
| 2290 | /* Add the eyevalues *e1 and *e2, leaving the result in *sum. It is |
| 2291 | * safe to let sum be the same as e1 or e2. |
| 2292 | */ |
| 2293 | void |
| 2294 | add_eyevalues(struct eyevalue *e1, struct eyevalue *e2, struct eyevalue *sum) |
| 2295 | { |
| 2296 | struct eyevalue res; |
| 2297 | res.a = gg_min(gg_min(e1->a + e2->c, e1->c + e2->a), |
| 2298 | gg_max(e1->a + e2->b, e1->b + e2->a)); |
| 2299 | res.b = gg_min(gg_max(e1->b + e2->b, gg_min(e1->a + e2->d, e1->b + e2->c)), |
| 2300 | gg_max(e1->b + e2->b, gg_min(e1->d + e2->a, e1->c + e2->b))); |
| 2301 | res.c = gg_max(gg_min(e1->c + e2->c, gg_max(e1->d + e2->a, e1->c + e2->b)), |
| 2302 | gg_min(e1->c + e2->c, gg_max(e1->a + e2->d, e1->b + e2->c))); |
| 2303 | res.d = gg_max(gg_max(e1->d + e2->b, e1->b + e2->d), |
| 2304 | gg_min(e1->d + e2->c, e1->c + e2->d)); |
| 2305 | |
| 2306 | /* The rules above give 0011 + 0002 = 0012, which is incorrect. Thus |
| 2307 | * we need this annoying exception. |
| 2308 | */ |
| 2309 | if ((e1->d - e1->c == 2 && e2->c - e2->b == 1) |
| 2310 | || (e1->c - e1->b == 1 && e2->d - e2->c == 2)) { |
| 2311 | res.d = gg_max(gg_min(e1->c + e2->d, e1->d + e2->b), |
| 2312 | gg_min(e1->d + e2->c, e1->b + e2->d)); |
| 2313 | } |
| 2314 | |
| 2315 | /* The temporary storage in res is necessary if sum is the same as |
| 2316 | * e1 or e2. |
| 2317 | */ |
| 2318 | sum->a = res.a; |
| 2319 | sum->b = res.b; |
| 2320 | sum->c = res.c; |
| 2321 | sum->d = res.d; |
| 2322 | } |
| 2323 | |
| 2324 | /* The impact on the number of eyes (counting up to two) if a vital |
| 2325 | * move is made. The possible values are |
| 2326 | * 0 - settled eye, no vital move |
| 2327 | * 2 - 1/2 eye or 3/2 eyes |
| 2328 | * 3 - 3/4 eyes or 5/4 eyes |
| 2329 | * 4 - 1* eyes (a chimera) |
| 2330 | */ |
| 2331 | int |
| 2332 | eye_move_urgency(struct eyevalue *e) |
| 2333 | { |
| 2334 | int a = gg_min(e->a, 2); |
| 2335 | int b = gg_min(e->b, 2); |
| 2336 | int c = gg_min(e->c, 2); |
| 2337 | int d = gg_min(e->d, 2); |
| 2338 | if (b == c) |
| 2339 | return 0; |
| 2340 | else |
| 2341 | return d + c - b - a; |
| 2342 | } |
| 2343 | |
| 2344 | /* Produces a string representing the eyevalue. |
| 2345 | * |
| 2346 | * Note: the result string is stored in a statically allocated buffer |
| 2347 | * which will be overwritten the next time this function is called. |
| 2348 | */ |
| 2349 | char * |
| 2350 | eyevalue_to_string(struct eyevalue *e) |
| 2351 | { |
| 2352 | static char result[30]; |
| 2353 | if (e->a < 10 && e->b < 10 && e->c < 10 && e->d < 10) |
| 2354 | gg_snprintf(result, 29, "%d%d%d%d", e->a, e->b, e->c, e->d); |
| 2355 | else |
| 2356 | gg_snprintf(result, 29, "[%d,%d,%d,%d]", e->a, e->b, e->c, e->d); |
| 2357 | return result; |
| 2358 | } |
| 2359 | |
| 2360 | |
| 2361 | |
| 2362 | /* Test whether the optics code evaluates an eyeshape consistently. */ |
| 2363 | void |
| 2364 | test_eyeshape(int eyesize, int *eye_vertices) |
| 2365 | { |
| 2366 | int k; |
| 2367 | int n, N; |
| 2368 | int mx[BOARDMAX]; |
| 2369 | int pos; |
| 2370 | int str = NO_MOVE; |
| 2371 | int attack_code; |
| 2372 | int attack_point; |
| 2373 | int defense_code; |
| 2374 | int defense_point; |
| 2375 | int save_verbose; |
| 2376 | struct board_state starting_position; |
| 2377 | |
| 2378 | /* Clear the board and initialize the engine properly. */ |
| 2379 | clear_board(); |
| 2380 | reset_engine(); |
| 2381 | |
| 2382 | /* Mark the eyespace in the mx array. */ |
| 2383 | memset(mx, 0, sizeof(mx)); |
| 2384 | for (k = 0; k < eyesize; k++) { |
| 2385 | ASSERT_ON_BOARD1(eye_vertices[k]); |
| 2386 | mx[eye_vertices[k]] = 1; |
| 2387 | } |
| 2388 | |
| 2389 | /* Play white stones surrounding the eyespace, including diagonals. */ |
| 2390 | for (pos = BOARDMIN; pos < BOARDMAX; pos++) { |
| 2391 | if (!ON_BOARD(pos) || mx[pos] == 1) |
| 2392 | continue; |
| 2393 | for (k = 0; k < 8; k++) { |
| 2394 | if (ON_BOARD(pos + delta[k]) && mx[pos + delta[k]] == 1) { |
| 2395 | play_move(pos, WHITE); |
| 2396 | str = pos; |
| 2397 | break; |
| 2398 | } |
| 2399 | } |
| 2400 | } |
| 2401 | |
| 2402 | /* Play black stones surrounding the white group, but leaving all |
| 2403 | * liberties empty. |
| 2404 | */ |
| 2405 | for (pos = BOARDMIN; pos < BOARDMAX; pos++) { |
| 2406 | if (mx[pos] == 1 || board[pos] != EMPTY || liberty_of_string(pos, str)) |
| 2407 | continue; |
| 2408 | for (k = 0; k < 8; k++) { |
| 2409 | if (ON_BOARD(pos + delta[k]) |
| 2410 | && liberty_of_string(pos + delta[k], str)) { |
| 2411 | play_move(pos, BLACK); |
| 2412 | break; |
| 2413 | } |
| 2414 | } |
| 2415 | } |
| 2416 | |
| 2417 | /* Show the board if verbose is on. Then turn off traces so we don't |
| 2418 | * get any from make_worms(), make_dragons(), or the owl reading. |
| 2419 | */ |
| 2420 | if (verbose) |
| 2421 | showboard(0); |
| 2422 | save_verbose = verbose; |
| 2423 | verbose = 0; |
| 2424 | |
| 2425 | |
| 2426 | /* Store this position so we can come back to it. */ |
| 2427 | store_board(&starting_position); |
| 2428 | |
| 2429 | /* Loop over all configurations of black stones inserted in the |
| 2430 | * eyeshape. There are N = 2^(eyesize) configurations and we can |
| 2431 | * straightforwardly use binary representation to enumerate them. |
| 2432 | */ |
| 2433 | N = 1 << eyesize; |
| 2434 | for (n = 0; n < N; n++) { |
| 2435 | int valid = 1; |
| 2436 | int internal_stones = 0; |
| 2437 | |
| 2438 | restore_board(&starting_position); |
| 2439 | /* Play the stones for this configuration. */ |
| 2440 | for (k = 0; k < eyesize; k++) { |
| 2441 | if (n & (1 << k)) { |
| 2442 | if (!is_legal(eye_vertices[k], BLACK)) { |
| 2443 | valid = 0; |
| 2444 | break; |
| 2445 | } |
| 2446 | play_move(eye_vertices[k], BLACK); |
| 2447 | internal_stones++; |
| 2448 | } |
| 2449 | } |
| 2450 | |
| 2451 | if (!valid) |
| 2452 | continue; |
| 2453 | |
| 2454 | if (save_verbose > 1) |
| 2455 | showboard(0); |
| 2456 | |
| 2457 | /* Now we are ready to test the consistency. This is most easily |
| 2458 | * done with help from the owl code. First we must prepare for |
| 2459 | * this though. |
| 2460 | */ |
| 2461 | examine_position(EXAMINE_DRAGONS_WITHOUT_OWL, 0); |
| 2462 | |
| 2463 | attack_code = owl_attack(str, &attack_point, NULL, NULL); |
| 2464 | |
| 2465 | if (attack_code == 0) { |
| 2466 | /* The owl code claims there is no attack. We test this by |
| 2467 | * trying to attack on all empty spaces in the eyeshape. |
| 2468 | */ |
| 2469 | for (k = 0; k < eyesize; k++) { |
| 2470 | if (board[eye_vertices[k]] == EMPTY |
| 2471 | && is_legal(eye_vertices[k], BLACK) |
| 2472 | && owl_does_attack(eye_vertices[k], str, NULL)) { |
| 2473 | gprintf("%1m alive, but %1m attacks:\n", str, eye_vertices[k]); |
| 2474 | showboard(0); |
| 2475 | gprintf("\n"); |
| 2476 | } |
| 2477 | } |
| 2478 | |
| 2479 | /* Furthermore, if the eyespace is almost filled, white should |
| 2480 | * be able to play on the remaining eyespace point and still be |
| 2481 | * alive. |
| 2482 | */ |
| 2483 | if (internal_stones == eyesize - 1) { |
| 2484 | for (k = 0; k < eyesize; k++) { |
| 2485 | if (board[eye_vertices[k]] == EMPTY |
| 2486 | && !owl_does_defend(eye_vertices[k], str, NULL)) { |
| 2487 | gprintf("%1m alive, but almost filled with nakade:\n", str); |
| 2488 | showboard(0); |
| 2489 | } |
| 2490 | } |
| 2491 | } |
| 2492 | } |
| 2493 | else { |
| 2494 | defense_code = owl_defend(str, &defense_point, NULL, NULL); |
| 2495 | if (defense_code == 0) { |
| 2496 | /* The owl code claims there is no defense. We test this by |
| 2497 | * trying to defend on all empty spaces in the eyeshape. |
| 2498 | */ |
| 2499 | for (k = 0; k < eyesize; k++) { |
| 2500 | if (board[eye_vertices[k]] == EMPTY |
| 2501 | && is_legal(eye_vertices[k], WHITE) |
| 2502 | && owl_does_defend(eye_vertices[k], str, NULL)) { |
| 2503 | gprintf("%1m dead, but %1m defends:\n", str, eye_vertices[k]); |
| 2504 | showboard(0); |
| 2505 | gprintf("\n"); |
| 2506 | } |
| 2507 | } |
| 2508 | } |
| 2509 | else { |
| 2510 | /* The owl code claims the dragon is critical. Verify the |
| 2511 | * attack and defense points. |
| 2512 | */ |
| 2513 | if (board[attack_point] != EMPTY |
| 2514 | || !is_legal(attack_point, BLACK)) { |
| 2515 | gprintf("Bad attack point %1m:\n", attack_point); |
| 2516 | showboard(0); |
| 2517 | } |
| 2518 | else if (!owl_does_attack(attack_point, str, NULL)) { |
| 2519 | gprintf("Attack point %1m failed:\n", attack_point); |
| 2520 | showboard(0); |
| 2521 | } |
| 2522 | |
| 2523 | if (board[defense_point] != EMPTY |
| 2524 | || !is_legal(defense_point, WHITE)) { |
| 2525 | gprintf("Bad defense point %1m:\n", defense_point); |
| 2526 | showboard(0); |
| 2527 | } |
| 2528 | else if (!owl_does_defend(defense_point, str, NULL)) { |
| 2529 | gprintf("Defense point %1m failed:\n", defense_point); |
| 2530 | showboard(0); |
| 2531 | } |
| 2532 | } |
| 2533 | } |
| 2534 | } |
| 2535 | verbose = save_verbose; |
| 2536 | } |
| 2537 | |
| 2538 | /******************************************************************** |
| 2539 | * The following static functions are helpers for analyze_eyegraph() |
| 2540 | * further down. The purpose is to evaluate eye graphs according to |
| 2541 | * the rules for local games, as described in doc/eyes.texi. |
| 2542 | * |
| 2543 | * The technique to do this is to convert the eye evaluation problem |
| 2544 | * into a tactical style life and death reading problem. Tactical in |
| 2545 | * the sense of needing to decide whether certain stones can be |
| 2546 | * captured, but not in the sense of the tactical reading that five |
| 2547 | * liberties are considered safe. |
| 2548 | * |
| 2549 | * We illustrate how this works with an example. Consider the eye shape |
| 2550 | * |
| 2551 | * ! |
| 2552 | * .X |
| 2553 | * !... |
| 2554 | * |
| 2555 | * The basic idea is to embed the eyespace in a perfectly connected |
| 2556 | * group without additional eyes or eye potential. This is most easily |
| 2557 | * done by the somewhat brutal trick to fill the entire board with |
| 2558 | * stones. We let the group consist of white stones (O) and get this |
| 2559 | * result, disregarding the two marginal eye vertices: |
| 2560 | * |
| 2561 | * A B C D E F G H J K L M N O P Q R S T |
| 2562 | * 19 O O O O O O O O O O O O O O O O O O O 19 |
| 2563 | * 18 O O O O O O O O O O O O O O O O O O O 18 |
| 2564 | * 17 O O O O O O O O O O O O O O O O O O O 17 |
| 2565 | * 16 O O O O O O O O O O O O O O O O O O O 16 |
| 2566 | * 15 O O O O O O O O O O O O O O O O O O O 15 |
| 2567 | * 14 O O O O O O O O O O O O O O O O O O O 14 |
| 2568 | * 13 O O O O O O O O O O O O O O O O O O O 13 |
| 2569 | * 12 O O O O O O O O . O O O O O O O O O O 12 |
| 2570 | * 11 O O O O O O O . X O O O O O O O O O O 11 |
| 2571 | * 10 O O O O O O . . . . O O O O O O O O O 10 |
| 2572 | * 9 O O O O O O O O O O O O O O O O O O O 9 |
| 2573 | * 8 O O O O O O O O O O O O O O O O O O O 8 |
| 2574 | * 7 O O O O O O O O O O O O O O O O O O O 7 |
| 2575 | * 6 O O O O O O O O O O O O O O O O O O O 6 |
| 2576 | * 5 O O O O O O O O O O O O O O O O O O O 5 |
| 2577 | * 4 O O O O O O O O O O O O O O O O O O O 4 |
| 2578 | * 3 O O O O O O O O O O O O O O O O O O O 3 |
| 2579 | * 2 O O O O O O O O O O O O O O O O O O O 2 |
| 2580 | * 1 O O O O O O O O O O O O O O O O O O O 1 |
| 2581 | * A B C D E F G H J K L M N O P Q R S T |
| 2582 | * |
| 2583 | * The question now is whether black can capture all the white stones |
| 2584 | * under alternating play where only white may pass. However, first we |
| 2585 | * need to make the top and leftmost eye vertices marginal. This is |
| 2586 | * done by inserting small invincible black groups in the sea of white |
| 2587 | * stones, in contact with the marginal vertices. |
| 2588 | * |
| 2589 | * A B C D E F G H J K L M N O P Q R S T |
| 2590 | * 19 . O O O O O O O O O O O O O O O O O O 19 |
| 2591 | * 18 O O O O O O O O X X X O O O O O O O O 18 |
| 2592 | * 17 O O O O O O O O X . X O O O O O O O O 17 |
| 2593 | * 16 O O O O O O O O X X X O O O O O O O O 16 |
| 2594 | * 15 O O O O O O O O X . X O O O O O O O O 15 |
| 2595 | * 14 O O O O O O O O X X X O O O O O O O O 14 |
| 2596 | * 13 O O O O O O O O X O O O O O O O O O O 13 |
| 2597 | * 12 O O O O O O O O . O O O O O O O O O O 12 |
| 2598 | * 11 O O O O O O O . X O O O O O O O O O O 11 |
| 2599 | * 10 O O O O O O . . . . O O O O O O O O O 10 |
| 2600 | * 9 O O O O O O X O O O O O O O O O O O O 9 |
| 2601 | * 8 O O O O X X X O O O O O O O O O O O O 8 |
| 2602 | * 7 O O O O X . X O O O O O O O O O O O O 7 |
| 2603 | * 6 O O O O X X X O O O O O O O O O O O O 6 |
| 2604 | * 5 O O O O X . X O O O O O O O O O O O O 5 |
| 2605 | * 4 . O O O X X X O O O O O O O O O O O O 4 |
| 2606 | * 3 X X . O O O O O O O O O O O O O O O O 3 |
| 2607 | * 2 X . X O O O O O O O O O O O O O O O O 2 |
| 2608 | * 1 . X X O O O O O O O O O O O O O O O O 1 |
| 2609 | * A B C D E F G H J K L M N O P Q R S T |
| 2610 | * |
| 2611 | * In this diagram we have also added an invincible black group in the |
| 2612 | * lower left corner in order to add two outer liberties (at A4 and |
| 2613 | * C3) for the white group (this is sometimes needed for the tactical |
| 2614 | * life and death reading to make sense). Furthermore there is an |
| 2615 | * extra eye at A19. This is used when we want to distinguish between |
| 2616 | * 0 and 1 (or 2) eyes since the tactical life and death reading by |
| 2617 | * itself only cares about two eyes or not. When trying to distinguish |
| 2618 | * between 1 (or 0) and 2 eyes we first fill in A19 again. |
| 2619 | * |
| 2620 | * Depending on the tactical life and death status with or without the |
| 2621 | * extra eye we can determine the number of eyes. By evaluating |
| 2622 | * tactical life and death status after having made a move we can also |
| 2623 | * identify ko threats and critical moves. |
| 2624 | * |
| 2625 | * This code is organized as follows: |
| 2626 | * |
| 2627 | * analyze_eyegraph() converts the eyegraph into the tactical board |
| 2628 | * position as demonstrated, then calls evaluate_eyespace() to its eye |
| 2629 | * value. |
| 2630 | * |
| 2631 | * white_area() is a helper to add a small invincible black group on |
| 2632 | * the board. |
| 2633 | * |
| 2634 | * evaluate_eyespace() calls tactical_life() and itself recursively to |
| 2635 | * determine the eye value and the critical points. |
| 2636 | * |
| 2637 | * tactical_life() determines whether the white stones on the board |
| 2638 | * (assumed to be a single string) can be captured under alternating |
| 2639 | * play. |
| 2640 | * |
| 2641 | * tactical_life_attack() and tactical_life_defend() are two mutually |
| 2642 | * recursive functions which perform the actual reading for |
| 2643 | * tactical_life(). |
| 2644 | * |
| 2645 | * Worth to mention in this overview is also the cache used for |
| 2646 | * tactical_life_attack() and tactical_life_defend(). Since we have a |
| 2647 | * limited number of vertices (eye space points + two outer liberties |
| 2648 | * + possibly an extra eye) to play on we use a complete cache with a |
| 2649 | * unique entry for every possible configuration of stones on the |
| 2650 | * considered vertices. |
| 2651 | * |
| 2652 | * For each cache entry four bits are used, two for attack results and |
| 2653 | * two four defense results. Each of these can take the values 0-3 |
| 2654 | * with the following interpretations: |
| 2655 | * 0 - not yet considered |
| 2656 | * 1 - result is being computed |
| 2657 | * 2 - result has been computed and was a failure (0) |
| 2658 | * 3 - result has been computed and was a success (1) |
| 2659 | */ |
| 2660 | |
| 2661 | /* Like trymove() except that it does a superko check. This does, |
| 2662 | * however, only disallow repetition (besides simple ko) if the move |
| 2663 | * does not capture any stones. |
| 2664 | */ |
| 2665 | static int |
| 2666 | eyegraph_trymove(int pos, int color, const char *message, int str) |
| 2667 | { |
| 2668 | static Hash_data remembered_board_hashes[MAXSTACK]; |
| 2669 | int k; |
| 2670 | int does_capture = does_capture_something(pos, color); |
| 2671 | |
| 2672 | remembered_board_hashes[stackp] = board_hash; |
| 2673 | |
| 2674 | if (!trymove(pos, color, message, str)) |
| 2675 | return 0; |
| 2676 | |
| 2677 | if (does_capture) |
| 2678 | return 1; |
| 2679 | |
| 2680 | for (k = 0; k < stackp; k++) |
| 2681 | if (hashdata_is_equal(board_hash, remembered_board_hashes[k])) { |
| 2682 | popgo(); |
| 2683 | return 0; |
| 2684 | } |
| 2685 | |
| 2686 | return 1; |
| 2687 | } |
| 2688 | |
| 2689 | static int |
| 2690 | eyegraph_is_margin_or_outer_liberty(int vertex) |
| 2691 | { |
| 2692 | int k; |
| 2693 | int r; |
| 2694 | int num_libs; |
| 2695 | int libs[MAXLIBS]; |
| 2696 | int eyes; |
| 2697 | |
| 2698 | for (k = 0; k < 4; k++) { |
| 2699 | if (board[vertex + delta[k]] == BLACK) { |
| 2700 | eyes = 0; |
| 2701 | num_libs = findlib(vertex + delta[k], MAXLIBS, libs); |
| 2702 | |
| 2703 | for (r = 0; r < num_libs; r++) |
| 2704 | if (is_suicide(libs[r], WHITE)) |
| 2705 | eyes++; |
| 2706 | |
| 2707 | if (eyes >= 2) |
| 2708 | return 1; |
| 2709 | } |
| 2710 | } |
| 2711 | return 0; |
| 2712 | } |
| 2713 | |
| 2714 | static int |
| 2715 | eyegraph_order_moves(int num_vertices, int *vertices, int color_to_move, int *moves) |
| 2716 | { |
| 2717 | int num_moves = 0; |
| 2718 | int scores[BOARDMAX]; |
| 2719 | int move; |
| 2720 | int score; |
| 2721 | int k; |
| 2722 | int r; |
| 2723 | |
| 2724 | for (k = 0; k < num_vertices; k++) { |
| 2725 | if (k >= num_vertices - 3) { |
| 2726 | /* Never useful for white to fill in outer liberties or a second eye. */ |
| 2727 | if (color_to_move == WHITE) |
| 2728 | break; |
| 2729 | /* No use playing the second outer liberty before the first one. */ |
| 2730 | if (k == num_vertices - 2 && board[vertices[num_vertices - 3]] == EMPTY) |
| 2731 | continue; |
| 2732 | } |
| 2733 | |
| 2734 | move = vertices[k]; |
| 2735 | score = 0; |
| 2736 | |
| 2737 | if (board[move] != EMPTY) |
| 2738 | continue; |
| 2739 | |
| 2740 | if (eyegraph_is_margin_or_outer_liberty(move)) { |
| 2741 | if (k < num_vertices - 3) |
| 2742 | score = 5; /* margin */ |
| 2743 | else |
| 2744 | score = -10; /* outer liberty */ |
| 2745 | } |
| 2746 | |
| 2747 | if (accuratelib(move, color_to_move, 2, NULL) == 1) |
| 2748 | score -= 3; |
| 2749 | |
| 2750 | for (r = 0; r < 4; r++) { |
| 2751 | if (board[move + delta[r]] == EMPTY) |
| 2752 | score += 2; |
| 2753 | else if (board[move + delta[r]] == BLACK) |
| 2754 | score += 3; |
| 2755 | } |
| 2756 | |
| 2757 | moves[num_moves] = move; |
| 2758 | scores[num_moves] = score; |
| 2759 | num_moves++; |
| 2760 | } |
| 2761 | |
| 2762 | for (k = 0; k < num_moves; k++) { |
| 2763 | int maxscore = scores[k]; |
| 2764 | int max_at = 0; |
| 2765 | |
| 2766 | /* Find the move with the biggest score. */ |
| 2767 | for (r = k + 1; r < num_moves; r++) { |
| 2768 | if (scores[r] > maxscore) { |
| 2769 | maxscore = scores[r]; |
| 2770 | max_at = r; |
| 2771 | } |
| 2772 | } |
| 2773 | |
| 2774 | /* Now exchange the move at k with the move at max_at. |
| 2775 | * Don't forget to exchange the scores as well. |
| 2776 | */ |
| 2777 | if (max_at != 0) { |
| 2778 | int temp = moves[max_at]; |
| 2779 | moves[max_at] = moves[k]; |
| 2780 | moves[k] = temp; |
| 2781 | temp = scores[max_at]; |
| 2782 | scores[max_at] = scores[k]; |
| 2783 | scores[k] = temp; |
| 2784 | } |
| 2785 | } |
| 2786 | |
| 2787 | return num_moves; |
| 2788 | } |
| 2789 | |
| 2790 | /* Place a small invincible black group on the board. |
| 2791 | * It is required that previously there were white stones at all |
| 2792 | * involved vertices and on the surrounding vertices. |
| 2793 | * |
| 2794 | * Returns 1 if a group was placed, 0 otherwise. |
| 2795 | */ |
| 2796 | static int |
| 2797 | white_area(int mx[BOARDMAX], int pos, int up, int right, int marginpos, |
| 2798 | int distance) |
| 2799 | { |
| 2800 | int u, v; |
| 2801 | int k; |
| 2802 | int edge = is_edge_vertex(marginpos); |
| 2803 | |
| 2804 | for (k = 1; k < distance; k++) |
| 2805 | if (!ON_BOARD(marginpos + k * up) |
| 2806 | || mx[marginpos + k * up] != WHITE) |
| 2807 | return 0; |
| 2808 | |
| 2809 | for (u = -1; u <= 4; u++) |
| 2810 | for (v = -1; v <= 4; v++) { |
| 2811 | int pos2 = pos + u * up + v * right; |
| 2812 | if (!ON_BOARD(pos2)) { |
| 2813 | if (!edge) |
| 2814 | return 0; |
| 2815 | else if (u >= 0 && u <= 3 && v >= 0 && v <= 3) |
| 2816 | return 0; |
| 2817 | else if (I(pos2) != I(NORTH(marginpos)) |
| 2818 | && I(pos2) != I(SOUTH(marginpos)) |
| 2819 | && J(pos2) != J(WEST(marginpos)) |
| 2820 | && J(pos2) != J(EAST(marginpos))) |
| 2821 | return 0; |
| 2822 | } |
| 2823 | else if (mx[pos2] != WHITE) |
| 2824 | return 0; |
| 2825 | } |
| 2826 | |
| 2827 | for (u = 0; u <= 3; u++) |
| 2828 | for (v = 0; v <= 3; v++) { |
| 2829 | int pos2 = pos + u * up + v * right; |
| 2830 | mx[pos2] = BLACK; |
| 2831 | } |
| 2832 | |
| 2833 | mx[pos + up + right] = EMPTY; |
| 2834 | mx[pos + 2 * up + 2 * right] = EMPTY; |
| 2835 | |
| 2836 | return 1; |
| 2837 | } |
| 2838 | |
| 2839 | |
| 2840 | #define EYEGRAPH_RETURN(result, trace) \ |
| 2841 | do { \ |
| 2842 | if (sgf_dumptree) \ |
| 2843 | sgftreeAddComment(sgf_dumptree, (trace)); \ |
| 2844 | return (result); \ |
| 2845 | } while (0); |
| 2846 | |
| 2847 | static int tactical_life_defend(int str, int num_vertices, int *vertices, |
| 2848 | unsigned char *results); |
| 2849 | |
| 2850 | /* Determine whether black can capture all white stones. */ |
| 2851 | static int |
| 2852 | tactical_life_attack(int str, int num_vertices, int *vertices, |
| 2853 | unsigned char *results) |
| 2854 | { |
| 2855 | int k; |
| 2856 | int hash = 0; |
| 2857 | int cached_result; |
| 2858 | int result; |
| 2859 | int num_moves; |
| 2860 | int moves[BOARDMAX]; |
| 2861 | |
| 2862 | /* Compute hash value to index the result cache with. */ |
| 2863 | for (k = 0; k < num_vertices; k++) { |
| 2864 | hash *= 3; |
| 2865 | hash += board[vertices[k]]; |
| 2866 | } |
| 2867 | hash *= 2; |
| 2868 | hash += (board_ko_pos != NO_MOVE); |
| 2869 | |
| 2870 | /* Is the result known from the cache? */ |
| 2871 | cached_result = results[hash] & 3; |
| 2872 | |
| 2873 | if (0) { |
| 2874 | showboard(0); |
| 2875 | gprintf("%d %d (%d)\n", hash, cached_result, results[hash]); |
| 2876 | } |
| 2877 | |
| 2878 | if (cached_result == 2) |
| 2879 | EYEGRAPH_RETURN(0, "tactical_life_attack: 0 (cached)"); |
| 2880 | if (cached_result == 3) |
| 2881 | EYEGRAPH_RETURN(1, "tactical_life_attack: win (cached)"); |
| 2882 | if (cached_result == 1) |
| 2883 | EYEGRAPH_RETURN(1, "tactical_life_attack: win (open node in cache)"); |
| 2884 | |
| 2885 | /* Mark this entry in the cache as currently being computed. */ |
| 2886 | results[hash] |= 1; |
| 2887 | |
| 2888 | /* Try to play on all relevant vertices. */ |
| 2889 | num_moves = eyegraph_order_moves(num_vertices, vertices, |
| 2890 | OTHER_COLOR(board[str]), moves); |
| 2891 | for (k = 0; k < num_moves; k++) { |
| 2892 | int move = moves[k]; |
| 2893 | if (eyegraph_trymove(move, OTHER_COLOR(board[str]), |
| 2894 | "tactical_life_attack", str)) { |
| 2895 | /* We were successful if the white stones were captured or if no |
| 2896 | * defense can be found. |
| 2897 | */ |
| 2898 | if (board[str] == EMPTY) |
| 2899 | result = 1; |
| 2900 | else |
| 2901 | result = !tactical_life_defend(str, num_vertices, vertices, results); |
| 2902 | |
| 2903 | popgo(); |
| 2904 | |
| 2905 | if (result == 1) { |
| 2906 | /* Store the result (success) in the cache. */ |
| 2907 | results[hash] = (results[hash] & (~3)) | 3; |
| 2908 | EYEGRAPH_RETURN(1, "tactical_life_attack: win"); |
| 2909 | } |
| 2910 | } |
| 2911 | } |
| 2912 | |
| 2913 | /* Store the result (failure) in the cache. */ |
| 2914 | results[hash] = (results[hash] & (~3)) | 2; |
| 2915 | EYEGRAPH_RETURN(0, "tactical_life_attack: 0"); |
| 2916 | } |
| 2917 | |
| 2918 | /* Determine whether white can live with all stones. */ |
| 2919 | static int |
| 2920 | tactical_life_defend(int str, int num_vertices, int *vertices, |
| 2921 | unsigned char *results) |
| 2922 | { |
| 2923 | int k; |
| 2924 | int hash = 0; |
| 2925 | int cached_result; |
| 2926 | int result; |
| 2927 | int num_moves; |
| 2928 | int moves[BOARDMAX]; |
| 2929 | |
| 2930 | /* Compute hash value to index the result cache with. */ |
| 2931 | for (k = 0; k < num_vertices; k++) { |
| 2932 | hash *= 3; |
| 2933 | ASSERT1(board[vertices[k]] <= 2, vertices[k]); |
| 2934 | hash += board[vertices[k]]; |
| 2935 | } |
| 2936 | hash *= 2; |
| 2937 | hash += (board_ko_pos != NO_MOVE); |
| 2938 | |
| 2939 | /* Is the result known from the cache? */ |
| 2940 | cached_result = (results[hash] >> 2) & 3; |
| 2941 | |
| 2942 | if (0) { |
| 2943 | showboard(0); |
| 2944 | gprintf("%d %d (%d)\n", hash, cached_result, results[hash]); |
| 2945 | } |
| 2946 | |
| 2947 | if (cached_result == 2) |
| 2948 | EYEGRAPH_RETURN(0, "tactical_life_defend: 0 (cached)"); |
| 2949 | if (cached_result == 3) |
| 2950 | EYEGRAPH_RETURN(1, "tactical_life_defend: win (cached)"); |
| 2951 | if (cached_result == 1) |
| 2952 | EYEGRAPH_RETURN(1, "tactical_life_defend: win (node open in cache)"); |
| 2953 | |
| 2954 | /* Mark this entry in the cache as currently being computed. */ |
| 2955 | results[hash] |= (1 << 2); |
| 2956 | |
| 2957 | /* Try to play on all relevant vertices. */ |
| 2958 | num_moves = eyegraph_order_moves(num_vertices, vertices, board[str], moves); |
| 2959 | for (k = 0; k < num_moves; k++) { |
| 2960 | int move = moves[k]; |
| 2961 | if ((!is_suicide(move, OTHER_COLOR(board[str])) |
| 2962 | || does_capture_something(move, board[str])) |
| 2963 | && eyegraph_trymove(move, board[str], "tactical_life_defend", str)) { |
| 2964 | /* We were successful if no attack can be found. */ |
| 2965 | result = !tactical_life_attack(str, num_vertices, vertices, results); |
| 2966 | |
| 2967 | popgo(); |
| 2968 | |
| 2969 | if (result == 1) { |
| 2970 | /* Store the result (success) in the cache. */ |
| 2971 | results[hash] = (results[hash] & (~12)) | (3 << 2); |
| 2972 | EYEGRAPH_RETURN(1, "tactical_life_defend: win"); |
| 2973 | } |
| 2974 | } |
| 2975 | } |
| 2976 | |
| 2977 | /* If no move worked, also try passing. */ |
| 2978 | if (!tactical_life_attack(str, num_vertices, vertices, results)) { |
| 2979 | /* Store the result (success) in the cache. */ |
| 2980 | results[hash] = (results[hash] & (~12)) | (3 << 2); |
| 2981 | EYEGRAPH_RETURN(1, "tactical_life_defend: win"); |
| 2982 | } |
| 2983 | |
| 2984 | /* Store the result (failure) in the cache. */ |
| 2985 | results[hash] = (results[hash] & (~12)) | (2 << 2); |
| 2986 | EYEGRAPH_RETURN(0, "tactical_life_defend: 0"); |
| 2987 | } |
| 2988 | |
| 2989 | /* Determine the tactical life and death status of all white stones. |
| 2990 | * Also find all attack and defense moves. The parameter have_eye |
| 2991 | * determines whether the extra eye in the upper left corner should be |
| 2992 | * used or filled in before starting reading. |
| 2993 | */ |
| 2994 | static void |
| 2995 | tactical_life(int have_eye, int num_vertices, int *vertices, |
| 2996 | int *attack_code, int *num_attacks, int *attack_points, |
| 2997 | int *defense_code, int *num_defenses, int *defense_points, |
| 2998 | unsigned char *results) |
| 2999 | { |
| 3000 | int k; |
| 3001 | int str; |
| 3002 | int num_moves; |
| 3003 | int moves[BOARDMAX]; |
| 3004 | |
| 3005 | gg_assert(attack_code != NULL && defense_code != NULL); |
| 3006 | |
| 3007 | /* We know that the large white group includes A18. This is the |
| 3008 | * vertex we test to determine whether the white stones have been |
| 3009 | * captured. |
| 3010 | */ |
| 3011 | str = POS(1, 0); |
| 3012 | |
| 3013 | if (board[str] == EMPTY) { |
| 3014 | /* The stones have already been captured, too late to defend. */ |
| 3015 | *attack_code = WIN; |
| 3016 | *defense_code = 0; |
| 3017 | return; |
| 3018 | } |
| 3019 | |
| 3020 | /* Fill in the extra eye if have_eye is 0. If filling in would be |
| 3021 | * suicide the white stones can be considered dead. |
| 3022 | */ |
| 3023 | if (!have_eye) { |
| 3024 | if (!eyegraph_trymove(POS(0, 0), WHITE, "tactical_life-A", NO_MOVE)) { |
| 3025 | *attack_code = WIN; |
| 3026 | *defense_code = 0; |
| 3027 | return; |
| 3028 | } |
| 3029 | } |
| 3030 | |
| 3031 | *attack_code = 0; |
| 3032 | *defense_code = 0; |
| 3033 | |
| 3034 | /* Call tactical_life_attack() and tactical_life_defend() to |
| 3035 | * determine status. |
| 3036 | */ |
| 3037 | if (tactical_life_attack(str, num_vertices, vertices, results)) { |
| 3038 | *attack_code = WIN; |
| 3039 | if (tactical_life_defend(str, num_vertices, vertices, results)) |
| 3040 | *defense_code = WIN; |
| 3041 | } |
| 3042 | else |
| 3043 | *defense_code = WIN; |
| 3044 | |
| 3045 | |
| 3046 | /* If the status is critical, try to play at each relevant vertex |
| 3047 | * and call tactical_life_defend() or tactical_life_attack() to |
| 3048 | * determine whether the move works as attack or defense. |
| 3049 | */ |
| 3050 | if (*attack_code != 0 && *defense_code != 0) { |
| 3051 | if (num_attacks != NULL && attack_points != NULL) { |
| 3052 | *num_attacks = 0; |
| 3053 | num_moves = eyegraph_order_moves(num_vertices, vertices, |
| 3054 | OTHER_COLOR(board[str]), moves); |
| 3055 | for (k = 0; k < num_moves; k++) { |
| 3056 | int move = moves[k]; |
| 3057 | if (eyegraph_trymove(move, OTHER_COLOR(board[str]), "tactical_life-B", |
| 3058 | str)) { |
| 3059 | if (board[str] == EMPTY |
| 3060 | || !tactical_life_defend(str, num_vertices, vertices, results)) |
| 3061 | attack_points[(*num_attacks)++] = move; |
| 3062 | popgo(); |
| 3063 | } |
| 3064 | } |
| 3065 | } |
| 3066 | |
| 3067 | if (num_defenses != NULL && defense_points != NULL) { |
| 3068 | *num_defenses = 0; |
| 3069 | num_moves = eyegraph_order_moves(num_vertices, vertices, board[str], |
| 3070 | moves); |
| 3071 | for (k = 0; k < num_moves; k++) { |
| 3072 | int move = moves[k]; |
| 3073 | if (eyegraph_trymove(move, board[str], "tactical_life-C", str)) { |
| 3074 | if (!tactical_life_attack(str, num_vertices, vertices, results)) |
| 3075 | defense_points[(*num_defenses)++] = move; |
| 3076 | popgo(); |
| 3077 | } |
| 3078 | } |
| 3079 | } |
| 3080 | } |
| 3081 | |
| 3082 | /* Unfill the extra eye if we didn't use it. */ |
| 3083 | if (!have_eye) |
| 3084 | popgo(); |
| 3085 | } |
| 3086 | |
| 3087 | /* Determine the eye value of the eyespace for the big white group on |
| 3088 | * the board and vital moves. The possible eye values are documented |
| 3089 | * in the preamble to eyes.db. By calling tactical_life() multiple |
| 3090 | * times, with and without using an extra eye, we can compute the eye |
| 3091 | * values. To determine ko threats and vital moves, tactical_life() is |
| 3092 | * called again after trying to play on one of the relevant vertices. |
| 3093 | * In order to find out whether ko threats really are effective and to |
| 3094 | * distinguish between 0122/1122 and 0012/0011 eye values (see |
| 3095 | * discussion on pattern 6141 in the preamble of eyes.db), we may also |
| 3096 | * need to recursively call ourselves after a move has been made. |
| 3097 | */ |
| 3098 | static void |
| 3099 | evaluate_eyespace(struct eyevalue *result, int num_vertices, int *vertices, |
| 3100 | int *num_vital_attacks, int *vital_attacks, |
| 3101 | int *num_vital_defenses, int *vital_defenses, |
| 3102 | unsigned char *tactical_life_results) |
| 3103 | { |
| 3104 | int k; |
| 3105 | int attack_code; |
| 3106 | int num_attacks; |
| 3107 | int attack_points[BOARDMAX]; |
| 3108 | int defense_code; |
| 3109 | int num_defenses; |
| 3110 | int defense_points[BOARDMAX]; |
| 3111 | int attack_code2; |
| 3112 | int num_attacks2; |
| 3113 | int attack_points2[BOARDMAX]; |
| 3114 | int defense_code2; |
| 3115 | struct eyevalue result2; |
| 3116 | int num_vital_attacks2; |
| 3117 | int vital_attacks2[BOARDMAX]; |
| 3118 | int num_vital_defenses2; |
| 3119 | int vital_defenses2[BOARDMAX]; |
| 3120 | int num_moves; |
| 3121 | int moves[BOARDMAX]; |
| 3122 | |
| 3123 | *num_vital_attacks = 0; |
| 3124 | *num_vital_defenses = 0; |
| 3125 | |
| 3126 | /* Determine tactical life without an extra eye. */ |
| 3127 | tactical_life(0, num_vertices, vertices, |
| 3128 | &attack_code, &num_attacks, attack_points, |
| 3129 | &defense_code, &num_defenses, defense_points, |
| 3130 | tactical_life_results); |
| 3131 | |
| 3132 | if (attack_code == 0) { |
| 3133 | /* Alive without extra eye. |
| 3134 | * Possible results: 0222, 1222, 2222 |
| 3135 | * |
| 3136 | * Determine whether there are ko threats and how serious. |
| 3137 | */ |
| 3138 | int a = 2; |
| 3139 | |
| 3140 | if (sgf_dumptree) |
| 3141 | sgftreeAddComment(sgf_dumptree, "Alive without extra eye.\n"); |
| 3142 | |
| 3143 | num_moves = eyegraph_order_moves(num_vertices, vertices, BLACK, moves); |
| 3144 | for (k = 0; k < num_moves; k++) { |
| 3145 | int acode, dcode; |
| 3146 | int move = moves[k]; |
| 3147 | if (eyegraph_trymove(move, BLACK, "evaluate_eyespace-A", NO_MOVE)) { |
| 3148 | tactical_life(0, num_vertices, vertices, &acode, NULL, NULL, |
| 3149 | &dcode, NULL, NULL, tactical_life_results); |
| 3150 | if (acode != 0) { |
| 3151 | tactical_life(1, num_vertices, vertices, &acode, NULL, NULL, |
| 3152 | &dcode, NULL, NULL, tactical_life_results); |
| 3153 | if (acode != 0) { |
| 3154 | if (a == 1) |
| 3155 | *num_vital_attacks = 0; |
| 3156 | a = 0; |
| 3157 | vital_attacks[(*num_vital_attacks)++] = move; |
| 3158 | if (sgf_dumptree) |
| 3159 | sgftreeAddComment(sgf_dumptree, |
| 3160 | "Ko threat to remove both eyes.\n"); |
| 3161 | } |
| 3162 | else { |
| 3163 | if (a != 0) { |
| 3164 | vital_attacks[(*num_vital_attacks)++] = move; |
| 3165 | a = 1; |
| 3166 | } |
| 3167 | if (sgf_dumptree) |
| 3168 | sgftreeAddComment(sgf_dumptree, "Ko threat to remove one eye.\n"); |
| 3169 | } |
| 3170 | } |
| 3171 | popgo(); |
| 3172 | } |
| 3173 | } |
| 3174 | set_eyevalue(result, a, 2, 2, 2); |
| 3175 | if (sgf_dumptree) { |
| 3176 | if (a == 0) |
| 3177 | sgftreeAddComment(sgf_dumptree, "Eyevalue 0222.\n"); |
| 3178 | else if (a == 1) |
| 3179 | sgftreeAddComment(sgf_dumptree, "Eyevalue 1222.\n"); |
| 3180 | else |
| 3181 | sgftreeAddComment(sgf_dumptree, "Eyevalue 2222.\n"); |
| 3182 | } |
| 3183 | } |
| 3184 | else if (defense_code != 0) { |
| 3185 | /* Critical without extra eye. |
| 3186 | * Possible results: 0022, 0122, 1122 |
| 3187 | */ |
| 3188 | if (sgf_dumptree) |
| 3189 | sgftreeAddComment(sgf_dumptree, "Critical without extra eye.\n"); |
| 3190 | tactical_life(1, num_vertices, vertices, |
| 3191 | &attack_code2, &num_attacks2, attack_points2, |
| 3192 | &defense_code2, NULL, NULL, tactical_life_results); |
| 3193 | for (k = 0; k < num_defenses; k++) |
| 3194 | vital_defenses[(*num_vital_defenses)++] = defense_points[k]; |
| 3195 | if (attack_code2 == WIN) { |
| 3196 | /* A chimera. 0022. */ |
| 3197 | set_eyevalue(result, 0, 0, 2, 2); |
| 3198 | for (k = 0; k < num_attacks2; k++) |
| 3199 | vital_attacks[(*num_vital_attacks)++] = attack_points2[k]; |
| 3200 | if (sgf_dumptree) |
| 3201 | sgftreeAddComment(sgf_dumptree, "Eyevalue: 0022.\n"); |
| 3202 | } |
| 3203 | else { |
| 3204 | int a = 1; |
| 3205 | for (k = 0; k < num_attacks; k++) { |
| 3206 | int move = attack_points[k]; |
| 3207 | if (eyegraph_trymove(move, BLACK, "evaluate_eyespace-B", NO_MOVE)) { |
| 3208 | evaluate_eyespace(&result2, num_vertices, vertices, |
| 3209 | &num_vital_attacks2, vital_attacks2, |
| 3210 | &num_vital_defenses2, vital_defenses2, |
| 3211 | tactical_life_results); |
| 3212 | /* If result2 is 0011 for some move we have 0122 as final |
| 3213 | * result, otherwise 1122. |
| 3214 | */ |
| 3215 | if (min_eyes(&result2) == 0 |
| 3216 | && max_eyes(&result2) == 1 |
| 3217 | && max_eye_threat(&result2) == 1) { |
| 3218 | if (a == 1) |
| 3219 | *num_vital_attacks = 0; |
| 3220 | a = 0; |
| 3221 | vital_attacks[(*num_vital_attacks)++] = move; |
| 3222 | } |
| 3223 | else if (a == 1) |
| 3224 | vital_attacks[(*num_vital_attacks)++] = move; |
| 3225 | popgo(); |
| 3226 | } |
| 3227 | } |
| 3228 | set_eyevalue(result, a, 1, 2, 2); |
| 3229 | if (sgf_dumptree) { |
| 3230 | if (a == 0) |
| 3231 | sgftreeAddComment(sgf_dumptree, "Eyevalue: 0122.\n"); |
| 3232 | else |
| 3233 | sgftreeAddComment(sgf_dumptree, "Eyevalue: 1122.\n"); |
| 3234 | } |
| 3235 | } |
| 3236 | } |
| 3237 | else { |
| 3238 | /* Dead without extra eye. |
| 3239 | * Possible results: 0000, 0001, 0002, 0011, 0012, 0111, 0112, 1111, 1112 |
| 3240 | * |
| 3241 | * Now determine tactical life with an extra eye. |
| 3242 | */ |
| 3243 | if (sgf_dumptree) |
| 3244 | sgftreeAddComment(sgf_dumptree, "Dead without extra eye.\n"); |
| 3245 | tactical_life(1, num_vertices, vertices, |
| 3246 | &attack_code, &num_attacks, attack_points, |
| 3247 | &defense_code, &num_defenses, defense_points, |
| 3248 | tactical_life_results); |
| 3249 | if (attack_code == 0) { |
| 3250 | /* Alive with extra eye. |
| 3251 | * Possible results: 0111, 0112, 1111, 1112 |
| 3252 | */ |
| 3253 | int a = 1; |
| 3254 | int d = 1; |
| 3255 | if (sgf_dumptree) |
| 3256 | sgftreeAddComment(sgf_dumptree, "Alive with extra eye.\n"); |
| 3257 | num_moves = eyegraph_order_moves(num_vertices, vertices, BLACK, moves); |
| 3258 | for (k = 0; k < num_moves; k++) { |
| 3259 | int acode, dcode; |
| 3260 | int move = moves[k]; |
| 3261 | if (eyegraph_trymove(move, BLACK, "evaluate_eyespace-C", NO_MOVE)) { |
| 3262 | tactical_life(1, num_vertices, vertices, &acode, NULL, NULL, |
| 3263 | &dcode, NULL, NULL, tactical_life_results); |
| 3264 | if (acode != 0) { |
| 3265 | evaluate_eyespace(&result2, num_vertices, vertices, |
| 3266 | &num_vital_attacks2, vital_attacks2, |
| 3267 | &num_vital_defenses2, vital_defenses2, |
| 3268 | tactical_life_results); |
| 3269 | /* This is either 0011 or 0012. Only the first is acceptable. */ |
| 3270 | if (max_eye_threat(&result2) == 1) { |
| 3271 | vital_attacks[(*num_vital_attacks)++] = move; |
| 3272 | a = 0; |
| 3273 | if (sgf_dumptree) |
| 3274 | sgftreeAddComment(sgf_dumptree, "Attacking ko threat.\n"); |
| 3275 | } |
| 3276 | } |
| 3277 | popgo(); |
| 3278 | } |
| 3279 | } |
| 3280 | |
| 3281 | num_moves = eyegraph_order_moves(num_vertices, vertices, WHITE, moves); |
| 3282 | for (k = 0; k < num_moves; k++) { |
| 3283 | int acode, dcode; |
| 3284 | int move = moves[k]; |
| 3285 | if (eyegraph_trymove(move, WHITE, "evaluate_eyespace-D", NO_MOVE)) { |
| 3286 | tactical_life(0, num_vertices, vertices, &acode, NULL, NULL, |
| 3287 | &dcode, NULL, NULL, tactical_life_results); |
| 3288 | if (dcode != 0) { |
| 3289 | evaluate_eyespace(&result2, num_vertices, vertices, |
| 3290 | &num_vital_attacks2, vital_attacks2, |
| 3291 | &num_vital_defenses2, vital_defenses2, |
| 3292 | tactical_life_results); |
| 3293 | /* This is either 1122 or 0122. Only the first is acceptable. */ |
| 3294 | if (min_eye_threat(&result2) == 1) { |
| 3295 | vital_defenses[(*num_vital_defenses)++] = move; |
| 3296 | d = 2; |
| 3297 | if (sgf_dumptree) |
| 3298 | sgftreeAddComment(sgf_dumptree, "Defending ko threat.\n"); |
| 3299 | } |
| 3300 | } |
| 3301 | popgo(); |
| 3302 | } |
| 3303 | } |
| 3304 | set_eyevalue(result, a, 1, 1, d); |
| 3305 | if (sgf_dumptree) { |
| 3306 | if (a == 0 && d == 1) |
| 3307 | sgftreeAddComment(sgf_dumptree, "Eyevalue 0111.\n"); |
| 3308 | else if (a == 0 && d == 2) |
| 3309 | sgftreeAddComment(sgf_dumptree, "Eyevalue 0112.\n"); |
| 3310 | else if (a == 1 && d == 1) |
| 3311 | sgftreeAddComment(sgf_dumptree, "Eyevalue 1111.\n"); |
| 3312 | else |
| 3313 | sgftreeAddComment(sgf_dumptree, "Eyevalue 1112.\n"); |
| 3314 | } |
| 3315 | } |
| 3316 | else if (defense_code != 0) { |
| 3317 | /* Critical with extra eye. |
| 3318 | * Possible results: 0011, 0012 |
| 3319 | */ |
| 3320 | int d = 1; |
| 3321 | if (sgf_dumptree) |
| 3322 | sgftreeAddComment(sgf_dumptree, "Critical with extra eye.\n"); |
| 3323 | for (k = 0; k < num_attacks; k++) |
| 3324 | vital_attacks[(*num_vital_attacks)++] = attack_points[k]; |
| 3325 | for (k = 0; k < num_defenses; k++) { |
| 3326 | int move = defense_points[k]; |
| 3327 | if (eyegraph_trymove(move, WHITE, "evaluate_eyespace-E", NO_MOVE)) { |
| 3328 | evaluate_eyespace(&result2, num_vertices, vertices, |
| 3329 | &num_vital_attacks2, vital_attacks2, |
| 3330 | &num_vital_defenses2, vital_defenses2, |
| 3331 | tactical_life_results); |
| 3332 | /* If result2 is 1122 for some move we have 0012 as final |
| 3333 | * result, otherwise 0011. |
| 3334 | */ |
| 3335 | if (min_eye_threat(&result2) == 1 |
| 3336 | && min_eyes(&result2) == 1 |
| 3337 | && max_eyes(&result2) == 2) { |
| 3338 | if (d == 1) |
| 3339 | *num_vital_defenses = 0; |
| 3340 | d = 2; |
| 3341 | vital_defenses[(*num_vital_defenses)++] = move; |
| 3342 | } |
| 3343 | else if (d == 1) |
| 3344 | vital_defenses[(*num_vital_defenses)++] = move; |
| 3345 | popgo(); |
| 3346 | } |
| 3347 | } |
| 3348 | set_eyevalue(result, 0, 0, 1, d); |
| 3349 | if (sgf_dumptree) { |
| 3350 | if (d == 1) |
| 3351 | sgftreeAddComment(sgf_dumptree, "Eyevalue: 0011.\n"); |
| 3352 | else |
| 3353 | sgftreeAddComment(sgf_dumptree, "Eyevalue: 0012.\n"); |
| 3354 | } |
| 3355 | } |
| 3356 | else { |
| 3357 | /* Dead with extra eye. |
| 3358 | * Possible results: 0000, 0001, 0002 |
| 3359 | * |
| 3360 | * Determine whether there are ko threats and how serious. |
| 3361 | */ |
| 3362 | int d = 0; |
| 3363 | if (sgf_dumptree) |
| 3364 | sgftreeAddComment(sgf_dumptree, "Dead with extra eye.\n"); |
| 3365 | num_moves = eyegraph_order_moves(num_vertices, vertices, WHITE, moves); |
| 3366 | for (k = 0; k < num_moves; k++) { |
| 3367 | int acode, dcode; |
| 3368 | int move = moves[k]; |
| 3369 | if (eyegraph_trymove(move, WHITE, "evaluate_eyespace-F", NO_MOVE)) { |
| 3370 | tactical_life(1, num_vertices, vertices, &acode, NULL, NULL, |
| 3371 | &dcode, NULL, NULL, tactical_life_results); |
| 3372 | if (dcode != 0) { |
| 3373 | tactical_life(0, num_vertices, vertices, &acode, NULL, NULL, |
| 3374 | &dcode, NULL, NULL, tactical_life_results); |
| 3375 | if (dcode != 0) { |
| 3376 | if (d == 1) |
| 3377 | *num_vital_defenses = 0; |
| 3378 | d = 2; |
| 3379 | vital_defenses[(*num_vital_defenses)++] = move; |
| 3380 | if (sgf_dumptree) |
| 3381 | sgftreeAddComment(sgf_dumptree, |
| 3382 | "Ko threat to make two eyes.\n"); |
| 3383 | } |
| 3384 | else { |
| 3385 | if (d != 2) { |
| 3386 | vital_defenses[(*num_vital_defenses)++] = move; |
| 3387 | d = 1; |
| 3388 | } |
| 3389 | if (sgf_dumptree) |
| 3390 | sgftreeAddComment(sgf_dumptree, |
| 3391 | "Ko threat to make one eye.\n"); |
| 3392 | } |
| 3393 | } |
| 3394 | popgo(); |
| 3395 | } |
| 3396 | } |
| 3397 | set_eyevalue(result, 0, 0, 0, d); |
| 3398 | if (sgf_dumptree) { |
| 3399 | if (d == 0) |
| 3400 | sgftreeAddComment(sgf_dumptree, "Eyevalue 0000.\n"); |
| 3401 | else if (d == 1) |
| 3402 | sgftreeAddComment(sgf_dumptree, "Eyevalue 0001.\n"); |
| 3403 | else |
| 3404 | sgftreeAddComment(sgf_dumptree, "Eyevalue 0002.\n"); |
| 3405 | } |
| 3406 | } |
| 3407 | } |
| 3408 | } |
| 3409 | |
| 3410 | /* Add small invincible black groups in contact with the marginal |
| 3411 | * vertices, without destroying the connectivity of the white stones. |
| 3412 | * |
| 3413 | */ |
| 3414 | static int |
| 3415 | add_margins(int num_margins, int *margins, int mx[BOARDMAX]) |
| 3416 | { |
| 3417 | int k; |
| 3418 | int i, j; |
| 3419 | int old_mx[BOARDMAX]; |
| 3420 | int pos; |
| 3421 | |
| 3422 | if (num_margins == 0) |
| 3423 | return 1; |
| 3424 | |
| 3425 | memcpy(old_mx, mx, sizeof(old_mx)); |
| 3426 | |
| 3427 | pos = margins[num_margins - 1]; |
| 3428 | |
| 3429 | for (k = 0; k < 4; k++) { |
| 3430 | int up = delta[k]; |
| 3431 | int right = delta[(k + 1) % 4]; |
| 3432 | |
| 3433 | if (!ON_BOARD(pos + up)) |
| 3434 | continue; |
| 3435 | |
| 3436 | if (mx[pos + up] == WHITE |
| 3437 | && (!ON_BOARD(pos + up + right) || mx[pos + up + right] == WHITE) |
| 3438 | && (!ON_BOARD(pos + up - right) || mx[pos + up - right] == WHITE)) { |
| 3439 | for (i = -3; i <= 0; i++) { |
| 3440 | for (j = 2; j < 6; j++) { |
| 3441 | if (white_area(mx, pos + j * up + i * right, up, right, pos, j)) { |
| 3442 | int s = 1; |
| 3443 | while (mx[pos + s * up] == WHITE) { |
| 3444 | mx[pos + s * up] = BLACK; |
| 3445 | s++; |
| 3446 | } |
| 3447 | if (add_margins(num_margins - 1, margins, mx)) |
| 3448 | return 1; |
| 3449 | else |
| 3450 | memcpy(mx, old_mx, sizeof(old_mx)); |
| 3451 | } |
| 3452 | } |
| 3453 | } |
| 3454 | } |
| 3455 | } |
| 3456 | |
| 3457 | return 0; |
| 3458 | } |
| 3459 | |
| 3460 | /* Analyze an eye graph to determine the eye value and vital moves. |
| 3461 | * |
| 3462 | * The eye graph is given by a string which is encoded with "%" for |
| 3463 | * newlines and "O" for spaces. E.g., the eye graph |
| 3464 | * |
| 3465 | * ! |
| 3466 | * .X |
| 3467 | * !... |
| 3468 | * |
| 3469 | * is encoded as "OO!%O.X%!...". (The encoding is needed for the GTP |
| 3470 | * interface to this function.) |
| 3471 | * |
| 3472 | * The result is an eye value and a (nonencoded) pattern showing the |
| 3473 | * vital moves, using the same notation as eyes.db. In the example above |
| 3474 | * we would get the eye value 0112 and the graph (showing ko threat moves) |
| 3475 | * |
| 3476 | * @ |
| 3477 | * .X |
| 3478 | * !.*. |
| 3479 | * |
| 3480 | * If the eye graph cannot be realized, 0 is returned, 1 otherwise. |
| 3481 | */ |
| 3482 | int |
| 3483 | analyze_eyegraph(const char *coded_eyegraph, struct eyevalue *value, |
| 3484 | char *analyzed_eyegraph) |
| 3485 | { |
| 3486 | int k; |
| 3487 | int i, j; |
| 3488 | int mini, minj; |
| 3489 | int mx[BOARDMAX]; |
| 3490 | char mg[BOARDMAX]; |
| 3491 | int pos; |
| 3492 | |
| 3493 | int num_vital_attacks; |
| 3494 | int vital_attacks[BOARDMAX]; /* Way larger than necessary. */ |
| 3495 | int num_vital_defenses; |
| 3496 | int vital_defenses[BOARDMAX]; /* Way larger than necessary. */ |
| 3497 | |
| 3498 | int maxwidth; |
| 3499 | int current_width; |
| 3500 | int num_rows; |
| 3501 | int horizontal_edge; |
| 3502 | int vertical_edge; |
| 3503 | |
| 3504 | int num_margins; |
| 3505 | int margins[BOARDMAX]; /* Way larger than necessary. */ |
| 3506 | |
| 3507 | int num_vertices; |
| 3508 | int vertices[BOARDMAX]; /* Way larger than necessary. */ |
| 3509 | |
| 3510 | int table_size; |
| 3511 | unsigned char *tactical_life_results; |
| 3512 | |
| 3513 | if (0) |
| 3514 | gprintf("Analyze eyegraph %s\n", coded_eyegraph); |
| 3515 | |
| 3516 | /* Mark the eyespace in the mx array. We construct the position in |
| 3517 | * the mx array and copy it to the actual board later. |
| 3518 | */ |
| 3519 | for (pos = BOARDMIN; pos < BOARDMAX; pos++) |
| 3520 | if (ON_BOARD(pos)) |
| 3521 | mx[pos] = WHITE; |
| 3522 | |
| 3523 | /* Find out the size of the eye graph pattern so that we can center |
| 3524 | * it properly. |
| 3525 | */ |
| 3526 | maxwidth = 0; |
| 3527 | current_width = 0; |
| 3528 | num_rows = 1; |
| 3529 | horizontal_edge = -1; |
| 3530 | vertical_edge = -1; |
| 3531 | for (k = 0; k < (int) strlen(coded_eyegraph); k++) { |
| 3532 | if (coded_eyegraph[k] == '\n') |
| 3533 | continue; |
| 3534 | if (coded_eyegraph[k] == '%') { |
| 3535 | num_rows++; |
| 3536 | if (current_width > maxwidth) |
| 3537 | maxwidth = current_width; |
| 3538 | current_width = 0; |
| 3539 | } |
| 3540 | else { |
| 3541 | if (coded_eyegraph[k] == '-') |
| 3542 | horizontal_edge = num_rows - 1; |
| 3543 | else if (coded_eyegraph[k] == '|') |
| 3544 | vertical_edge = current_width; |
| 3545 | current_width++; |
| 3546 | } |
| 3547 | } |
| 3548 | if (current_width > maxwidth) |
| 3549 | maxwidth = current_width; |
| 3550 | |
| 3551 | /* Cut out the eyespace from the solid white string. */ |
| 3552 | num_margins = 0; |
| 3553 | num_vertices = 0; |
| 3554 | |
| 3555 | if (horizontal_edge == 0) |
| 3556 | mini = -1; |
| 3557 | else if (horizontal_edge > 0) |
| 3558 | mini = board_size - num_rows + 1; |
| 3559 | else |
| 3560 | mini = (board_size - num_rows) / 2; |
| 3561 | |
| 3562 | if (vertical_edge == 0) |
| 3563 | minj = -1; |
| 3564 | else if (vertical_edge > 0) |
| 3565 | minj = board_size - maxwidth + 1; |
| 3566 | else |
| 3567 | minj = (board_size - maxwidth) / 2; |
| 3568 | |
| 3569 | i = mini; |
| 3570 | j = minj; |
| 3571 | for (k = 0; k < (int) strlen(coded_eyegraph); k++) { |
| 3572 | char c = coded_eyegraph[k]; |
| 3573 | if (c == '\n') |
| 3574 | continue; |
| 3575 | if (c == '%') { |
| 3576 | i++; |
| 3577 | j = minj - 1; |
| 3578 | } |
| 3579 | else if (c == 'X' || c == '$') |
| 3580 | mx[POS(i, j)] = BLACK; |
| 3581 | else if (c == '.' || c == '*' || c == '<' || c == '>' |
| 3582 | || c == '!' || c == '@' || c == '(' || c == ')') |
| 3583 | mx[POS(i, j)] = EMPTY; |
| 3584 | if (c == '!' || c == '@' || c == '(' || c == ')' || c == '$') |
| 3585 | margins[num_margins++] = POS(i, j); |
| 3586 | if (c != '|' && c != '-' && c != '+' && c != '%' |
| 3587 | && ON_BOARD(POS(i, j)) && mx[POS(i, j)] != WHITE) |
| 3588 | vertices[num_vertices++] = POS(i, j); |
| 3589 | j++; |
| 3590 | } |
| 3591 | |
| 3592 | /* Add an invincible black group in the lower left plus two outer |
| 3593 | * liberties for the white string. However, if the eyespace is |
| 3594 | * placed in or near the lower left corner, we put this group in the |
| 3595 | * upper right instead. |
| 3596 | */ |
| 3597 | pos = POS(board_size - 2, 1); |
| 3598 | if ((vertical_edge == 0 && horizontal_edge != 0) |
| 3599 | || (horizontal_edge > 0 && vertical_edge <= 0)) |
| 3600 | pos = POS(1, board_size - 2); |
| 3601 | mx[pos] = EMPTY; |
| 3602 | mx[NORTH(pos)] = BLACK; |
| 3603 | mx[NW(pos)] = BLACK; |
| 3604 | mx[NE(pos)] = EMPTY; |
| 3605 | mx[WEST(pos)] = BLACK; |
| 3606 | mx[EAST(pos)] = BLACK; |
| 3607 | mx[SW(pos)] = EMPTY; |
| 3608 | mx[SOUTH(pos)] = BLACK; |
| 3609 | mx[SE(pos)] = BLACK; |
| 3610 | if (ON_BOARD(NN(pos))) |
| 3611 | mx[NN(pos)] = EMPTY; |
| 3612 | else |
| 3613 | mx[SS(pos)] = EMPTY; |
| 3614 | |
| 3615 | /* Add the two outer liberties in the lower left or upper right to |
| 3616 | * the list of vertices. |
| 3617 | */ |
| 3618 | if (ON_BOARD(NN(pos))) { |
| 3619 | vertices[num_vertices++] = NE(pos); |
| 3620 | vertices[num_vertices++] = NN(pos); |
| 3621 | } |
| 3622 | else { |
| 3623 | vertices[num_vertices++] = SW(pos); |
| 3624 | vertices[num_vertices++] = SS(pos); |
| 3625 | } |
| 3626 | |
| 3627 | /* Add an extra eye in the upper left corner. */ |
| 3628 | mx[POS(0, 0)] = EMPTY; |
| 3629 | vertices[num_vertices++] = POS(0, 0); |
| 3630 | |
| 3631 | if (!add_margins(num_margins, margins, mx)) |
| 3632 | return 0; |
| 3633 | |
| 3634 | /* Copy the mx array over to the board. */ |
| 3635 | clear_board(); |
| 3636 | for (pos = BOARDMIN; pos < BOARDMAX; pos++) |
| 3637 | if (ON_BOARD(pos)) { |
| 3638 | if (mx[pos] == WHITE) |
| 3639 | add_stone(pos, WHITE); |
| 3640 | else if (mx[pos] == BLACK) |
| 3641 | add_stone(pos, BLACK); |
| 3642 | } |
| 3643 | |
| 3644 | if (verbose) |
| 3645 | showboard(0); |
| 3646 | |
| 3647 | /* If there are any isolated O stones, those should also be added to |
| 3648 | * the playable vertices. |
| 3649 | */ |
| 3650 | for (pos = BOARDMIN; pos < BOARDMAX; pos++) |
| 3651 | if (board[pos] == WHITE && !same_string(pos, POS(1, 0))) { |
| 3652 | vertices[num_vertices] = vertices[num_vertices - 1]; |
| 3653 | vertices[num_vertices - 1] = vertices[num_vertices - 2]; |
| 3654 | vertices[num_vertices - 2] = vertices[num_vertices - 3]; |
| 3655 | vertices[num_vertices - 3] = pos; |
| 3656 | num_vertices++; |
| 3657 | } |
| 3658 | |
| 3659 | if (verbose) { |
| 3660 | int k; |
| 3661 | gprintf("\nPlayable vertices:\n"); |
| 3662 | for (k = 0; k < num_vertices; k++) |
| 3663 | gprintf("%1m ", vertices[k]); |
| 3664 | gprintf("\n\n"); |
| 3665 | } |
| 3666 | |
| 3667 | /* Disable this test if you need to evaluate larger eyespaces, have |
| 3668 | * no shortage of memory, and know what you're doing. |
| 3669 | */ |
| 3670 | if (num_vertices > 17) { |
| 3671 | gprintf("analyze_eyegraph: too large eyespace, %d vertices\n", |
| 3672 | num_vertices); |
| 3673 | gg_assert(num_vertices <= 17); |
| 3674 | } |
| 3675 | |
| 3676 | /* The cache must have 2*3^num_vertices entries. */ |
| 3677 | table_size = 2; |
| 3678 | for (k = 0; k < num_vertices; k++) |
| 3679 | table_size *= 3; |
| 3680 | |
| 3681 | /* Allocate memory for the cache. */ |
| 3682 | tactical_life_results = malloc(table_size); |
| 3683 | if (!tactical_life_results) { |
| 3684 | gprintf("analyze_eyegraph: failed to allocate %d bytes\n", table_size); |
| 3685 | gg_assert(tactical_life_results != NULL); |
| 3686 | } |
| 3687 | memset(tactical_life_results, 0, table_size); |
| 3688 | |
| 3689 | if (sgf_dumptree) |
| 3690 | sgffile_printboard(sgf_dumptree); |
| 3691 | |
| 3692 | /* Evaluate the eyespace on the board. */ |
| 3693 | evaluate_eyespace(value, num_vertices, vertices, |
| 3694 | &num_vital_attacks, vital_attacks, |
| 3695 | &num_vital_defenses, vital_defenses, |
| 3696 | tactical_life_results); |
| 3697 | |
| 3698 | /* Return the cache memory. */ |
| 3699 | free(tactical_life_results); |
| 3700 | |
| 3701 | if (verbose) { |
| 3702 | gprintf("Eyevalue: %s\n", eyevalue_to_string(value)); |
| 3703 | for (k = 0; k < num_vital_attacks; k++) |
| 3704 | gprintf(" vital attack point %1m\n", vital_attacks[k]); |
| 3705 | for (k = 0; k < num_vital_defenses; k++) |
| 3706 | gprintf(" vital defense point %1m\n", vital_defenses[k]); |
| 3707 | } |
| 3708 | |
| 3709 | /* Encode the attack and defense points with symbols in the mg[] array. */ |
| 3710 | memset(mg, ' ', sizeof(mg)); |
| 3711 | |
| 3712 | for (k = 0; k < num_vertices - 2; k++) |
| 3713 | mg[vertices[k]] = (board[vertices[k]] == BLACK ? 'X' : '.'); |
| 3714 | |
| 3715 | for (k = 0; k < num_margins; k++) |
| 3716 | mg[margins[k]] = (mg[margins[k]] == 'X' ? '$' : '!'); |
| 3717 | |
| 3718 | for (k = 0; k < num_vital_attacks; k++) |
| 3719 | mg[vital_attacks[k]] = (mg[vital_attacks[k]] == '!' ? '(' : '<'); |
| 3720 | |
| 3721 | for (k = 0; k < num_vital_defenses; k++) { |
| 3722 | int pos = vital_defenses[k]; |
| 3723 | if (mg[pos] == '.') |
| 3724 | mg[pos] = '>'; |
| 3725 | else if (mg[pos] == '!') |
| 3726 | mg[pos] = ')'; |
| 3727 | else if (mg[pos] == '<') |
| 3728 | mg[pos] = '*'; |
| 3729 | else if (mg[pos] == '(') |
| 3730 | mg[pos] = '@'; |
| 3731 | } |
| 3732 | |
| 3733 | /* Return the central part of the mg[] array (corresponding to the |
| 3734 | * input eye graph). |
| 3735 | */ |
| 3736 | k = 0; |
| 3737 | for (i = mini; i < mini + num_rows; i++) { |
| 3738 | for (j = minj; j < minj + maxwidth; j++) { |
| 3739 | if ((i < 0 || i >= board_size) && (j < 0 || j >= board_size)) |
| 3740 | analyzed_eyegraph[k++] = '+'; |
| 3741 | else if (i < 0 || i >= board_size) |
| 3742 | analyzed_eyegraph[k++] = '-'; |
| 3743 | else if (j < 0 || j >= board_size) |
| 3744 | analyzed_eyegraph[k++] = '|'; |
| 3745 | else |
| 3746 | analyzed_eyegraph[k++] = mg[POS(i, j)]; |
| 3747 | } |
| 3748 | analyzed_eyegraph[k++] = '\n'; |
| 3749 | } |
| 3750 | analyzed_eyegraph[k - 1] = 0; |
| 3751 | |
| 3752 | return 1; |
| 3753 | } |
| 3754 | |
| 3755 | |
| 3756 | /* |
| 3757 | * Local Variables: |
| 3758 | * tab-width: 8 |
| 3759 | * c-basic-offset: 2 |
| 3760 | * End: |
| 3761 | */ |