| 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 "liberty.h" |
| 27 | #include "patterns.h" |
| 28 | #include "random.h" |
| 29 | |
| 30 | /* ================================================================ */ |
| 31 | /* Set up fixed placement handicap stones for black side */ |
| 32 | /* ================================================================ */ |
| 33 | |
| 34 | |
| 35 | /* Handicap stones are set up according to the following diagrams: |
| 36 | * |
| 37 | * 2 stones: 3 stones: |
| 38 | * |
| 39 | * A B C D E F G H J A B C D E F G H J |
| 40 | * 9 . . . . . . . . . 9 9 . . . . . . . . . 9 |
| 41 | * 8 . . . . . . . . . 8 8 . . . . . . . . . 8 |
| 42 | * 7 . . + . . . X . . 7 7 . . X . . . X . . 7 |
| 43 | * 6 . . . . . . . . . 6 6 . . . . . . . . . 6 |
| 44 | * 5 . . . . + . . . . 5 5 . . . . + . . . . 5 |
| 45 | * 4 . . . . . . . . . 4 4 . . . . . . . . . 4 |
| 46 | * 3 . . X . . . + . . 3 3 . . X . . . + . . 3 |
| 47 | * 2 . . . . . . . . . 2 2 . . . . . . . . . 2 |
| 48 | * 1 . . . . . . . . . 1 1 . . . . . . . . . 1 |
| 49 | * A B C D E F G H J A B C D E F G H J |
| 50 | * |
| 51 | * 4 stones: 5 stones: |
| 52 | * |
| 53 | * A B C D E F G H J A B C D E F G H J |
| 54 | * 9 . . . . . . . . . 9 9 . . . . . . . . . 9 |
| 55 | * 8 . . . . . . . . . 8 8 . . . . . . . . . 8 |
| 56 | * 7 . . X . . . X . . 7 7 . . X . . . X . . 7 |
| 57 | * 6 . . . . . . . . . 6 6 . . . . . . . . . 6 |
| 58 | * 5 . . . . + . . . . 5 5 . . . . X . . . . 5 |
| 59 | * 4 . . . . . . . . . 4 4 . . . . . . . . . 4 |
| 60 | * 3 . . X . . . X . . 3 3 . . X . . . X . . 3 |
| 61 | * 2 . . . . . . . . . 2 2 . . . . . . . . . 2 |
| 62 | * 1 . . . . . . . . . 1 1 . . . . . . . . . 1 |
| 63 | * A B C D E F G H J A B C D E F G H J |
| 64 | * |
| 65 | * 6 stones: 7 stones: |
| 66 | * |
| 67 | * A B C D E F G H J A B C D E F G H J |
| 68 | * 9 . . . . . . . . . 9 9 . . . . . . . . . 9 |
| 69 | * 8 . . . . . . . . . 8 8 . . . . . . . . . 8 |
| 70 | * 7 . . X . . . X . . 7 7 . . X . . . X . . 7 |
| 71 | * 6 . . . . . . . . . 6 6 . . . . . . . . . 6 |
| 72 | * 5 . . X . + . X . . 5 5 . . X . X . X . . 5 |
| 73 | * 4 . . . . . . . . . 4 4 . . . . . . . . . 4 |
| 74 | * 3 . . X . . . X . . 3 3 . . X . . . X . . 3 |
| 75 | * 2 . . . . . . . . . 2 2 . . . . . . . . . 2 |
| 76 | * 1 . . . . . . . . . 1 1 . . . . . . . . . 1 |
| 77 | * A B C D E F G H J A B C D E F G H J |
| 78 | * |
| 79 | * 8 stones: 9 stones: |
| 80 | * |
| 81 | * A B C D E F G H J A B C D E F G H J |
| 82 | * 9 . . . . . . . . . 9 9 . . . . . . . . . 9 |
| 83 | * 8 . . . . . . . . . 8 8 . . . . . . . . . 8 |
| 84 | * 7 . . X . X . X . . 7 7 . . X . X . X . . 7 |
| 85 | * 6 . . . . . . . . . 6 6 . . . . . . . . . 6 |
| 86 | * 5 . . X . + . X . . 5 5 . . X . X . X . . 5 |
| 87 | * 4 . . . . . . . . . 4 4 . . . . . . . . . 4 |
| 88 | * 3 . . X . X . X . . 3 3 . . X . X . X . . 3 |
| 89 | * 2 . . . . . . . . . 2 2 . . . . . . . . . 2 |
| 90 | * 1 . . . . . . . . . 1 1 . . . . . . . . . 1 |
| 91 | * A B C D E F G H J A B C D E F G H J |
| 92 | * |
| 93 | * For odd-sized boards larger than 9x9, the same pattern is followed, |
| 94 | * except that the edge stones are moved to the fourth line for 13x13 |
| 95 | * boards and larger. |
| 96 | * |
| 97 | * For even-sized boards at least 8x8, only the four first diagrams |
| 98 | * are used, because there is no way to place the center stones |
| 99 | * symmetrically. As for odd-sized boards, the edge stones are moved |
| 100 | * to the fourth line for boards larger than 11x11. |
| 101 | * |
| 102 | * At most four stones are placed on 7x7 boards too (this size may or |
| 103 | * may not be supported by the rest of the engine). No handicap stones |
| 104 | * are ever placed on smaller boards. |
| 105 | * |
| 106 | * Notice that this function only deals with fixed handicap placement. |
| 107 | * Larger handicaps can be added by free placement if the used |
| 108 | * interface supports it. |
| 109 | */ |
| 110 | |
| 111 | |
| 112 | /* This table contains the (coded) positions of the stones. |
| 113 | * 2 maps to 2 or 3, depending on board size |
| 114 | * 0 maps to center |
| 115 | * -ve numbers map to board_size - number |
| 116 | * |
| 117 | * The stones are placed in this order, *except* if there are |
| 118 | * 5 or 7 stones, in which case center ({0, 0}) is placed, and |
| 119 | * then as for 4 or 6. |
| 120 | */ |
| 121 | |
| 122 | static const int places[][2] = { |
| 123 | |
| 124 | {2, -2}, {-2, 2}, {2, 2}, {-2, -2}, /* first 4 are easy */ |
| 125 | /* for 5, {0,0} is explicitly placed */ |
| 126 | |
| 127 | {0, 2}, {0, -2}, /* for 6 these two are placed */ |
| 128 | /* for 7, {0,0} is explicitly placed */ |
| 129 | |
| 130 | {2, 0}, {-2, 0}, /* for 8, these two are placed */ |
| 131 | |
| 132 | {0, 0}, /* finally tengen for 9 */ |
| 133 | }; |
| 134 | |
| 135 | |
| 136 | /* |
| 137 | * Sets up fixed handicap placement stones, returning the number of |
| 138 | * placed handicap stones and also setting the global variable |
| 139 | * handicap to the same value. |
| 140 | */ |
| 141 | |
| 142 | int |
| 143 | place_fixed_handicap(int desired_handicap) |
| 144 | { |
| 145 | int r; |
| 146 | int max_handicap; |
| 147 | int remaining_stones; |
| 148 | int three = board_size > 11 ? 3 : 2; |
| 149 | int mid = board_size/2; |
| 150 | |
| 151 | /* A handicap of 1 just means that B plays first, no komi. |
| 152 | * Black is not told where to play the first stone so no handicap |
| 153 | * is set. |
| 154 | */ |
| 155 | if (desired_handicap < 2) { |
| 156 | handicap = 0; |
| 157 | return 0; |
| 158 | } |
| 159 | |
| 160 | if ((board_size % 2 == 1) && (board_size >= 9)) |
| 161 | max_handicap = 9; |
| 162 | else if (board_size >= 7) |
| 163 | max_handicap = 4; |
| 164 | else |
| 165 | max_handicap = 0; |
| 166 | |
| 167 | /* It's up to the caller of this function to notice if the handicap |
| 168 | * was too large for fixed placement and act upon that. |
| 169 | */ |
| 170 | if (desired_handicap > max_handicap) |
| 171 | handicap = max_handicap; |
| 172 | else |
| 173 | handicap = desired_handicap; |
| 174 | |
| 175 | remaining_stones = handicap; |
| 176 | /* special cases: 5 and 7 */ |
| 177 | if (desired_handicap == 5 || desired_handicap == 7) { |
| 178 | add_stone(POS(mid, mid), BLACK); |
| 179 | remaining_stones--; |
| 180 | } |
| 181 | |
| 182 | for (r = 0; r < remaining_stones; r++) { |
| 183 | int i = places[r][0]; |
| 184 | int j = places[r][1]; |
| 185 | |
| 186 | /* Translate the encoded values to board co-ordinates. */ |
| 187 | if (i == 2) |
| 188 | i = three; /* 2 or 3 */ |
| 189 | else if (i == 0) |
| 190 | i = mid; |
| 191 | else if (i == -2) |
| 192 | i = board_size - 1 - three; |
| 193 | |
| 194 | if (j == 2) |
| 195 | j = three; |
| 196 | else if (j == 0) |
| 197 | j = mid; |
| 198 | else if (j == -2) |
| 199 | j = board_size - 1 - three; |
| 200 | |
| 201 | add_stone(POS(i, j), BLACK); |
| 202 | } |
| 203 | |
| 204 | return handicap; |
| 205 | } |
| 206 | |
| 207 | |
| 208 | /* ================================================================ */ |
| 209 | /* Set up free placement handicap stones for black side */ |
| 210 | /* ================================================================ */ |
| 211 | |
| 212 | |
| 213 | /* |
| 214 | * Sets up free handicap placement stones, returning the number of |
| 215 | * placed handicap stones. |
| 216 | */ |
| 217 | |
| 218 | static int remaining_handicap_stones = -1; |
| 219 | static int total_handicap_stones = -1; |
| 220 | |
| 221 | static int find_free_handicap_pattern(void); |
| 222 | static void free_handicap_callback(int anchor, int color, |
| 223 | struct pattern *pattern, |
| 224 | int ll, void *data); |
| 225 | |
| 226 | /* |
| 227 | * Sets up free placement handicap stones, returning the number of |
| 228 | * placed handicap stones and also setting the global variable |
| 229 | * handicap to the same value. |
| 230 | */ |
| 231 | int |
| 232 | place_free_handicap(int desired_handicap) |
| 233 | { |
| 234 | gg_assert(desired_handicap == 0 || desired_handicap >= 2); |
| 235 | |
| 236 | if (desired_handicap == 0) { |
| 237 | handicap = 0; |
| 238 | return 0; |
| 239 | } |
| 240 | |
| 241 | total_handicap_stones = desired_handicap; |
| 242 | remaining_handicap_stones = desired_handicap; |
| 243 | |
| 244 | /* First place black stones in the four corners to enable the |
| 245 | * pattern matching scheme. |
| 246 | */ |
| 247 | add_stone(POS(0, 0), BLACK); |
| 248 | add_stone(POS(0, board_size - 1), BLACK); |
| 249 | add_stone(POS(board_size - 1, 0), BLACK); |
| 250 | add_stone(POS(board_size - 1, board_size - 1), BLACK); |
| 251 | |
| 252 | /* Find and place free handicap stones by pattern matching. */ |
| 253 | while (remaining_handicap_stones > 0) { |
| 254 | if (!find_free_handicap_pattern()) |
| 255 | break; |
| 256 | } |
| 257 | |
| 258 | /* Remove the artificial corner stones. */ |
| 259 | remove_stone(POS(0, 0)); |
| 260 | remove_stone(POS(0, board_size - 1)); |
| 261 | remove_stone(POS(board_size - 1, 0)); |
| 262 | remove_stone(POS(board_size - 1, board_size - 1)); |
| 263 | |
| 264 | /* Find and place additional free handicap stones by the aftermath |
| 265 | * algorithm. |
| 266 | */ |
| 267 | while (remaining_handicap_stones > 0) { |
| 268 | int move; |
| 269 | /* Call genmove_conservative() in order to prepare the engine for |
| 270 | * an aftermath_genmove() call. We discard the genmove result. |
| 271 | */ |
| 272 | genmove_conservative(BLACK, NULL); |
| 273 | move = aftermath_genmove(BLACK, 0, NULL); |
| 274 | if (move != PASS_MOVE) { |
| 275 | add_stone(move, BLACK); |
| 276 | remaining_handicap_stones--; |
| 277 | } |
| 278 | else |
| 279 | break; |
| 280 | } |
| 281 | |
| 282 | /* Set handicap to the number of actually placed stones. */ |
| 283 | handicap = desired_handicap - remaining_handicap_stones; |
| 284 | |
| 285 | /* Reset these to invalid values, so that improper use of handicap |
| 286 | * helper functions can be detected. |
| 287 | */ |
| 288 | total_handicap_stones = -1; |
| 289 | remaining_handicap_stones = -1; |
| 290 | |
| 291 | return handicap; |
| 292 | } |
| 293 | |
| 294 | struct handicap_match { |
| 295 | int value; |
| 296 | int anchor; |
| 297 | struct pattern *pattern; |
| 298 | int ll; |
| 299 | }; |
| 300 | |
| 301 | #define MAX_HANDICAP_MATCHES 40 |
| 302 | |
| 303 | static struct handicap_match handicap_matches[MAX_HANDICAP_MATCHES]; |
| 304 | static int number_of_matches; |
| 305 | |
| 306 | static int |
| 307 | find_free_handicap_pattern() |
| 308 | { |
| 309 | int k; |
| 310 | int highest_value = -1; |
| 311 | int sum_values = 0; |
| 312 | int r; |
| 313 | int anchor; |
| 314 | struct pattern *pattern; |
| 315 | int ll; |
| 316 | int move; |
| 317 | |
| 318 | number_of_matches = 0; |
| 319 | matchpat(free_handicap_callback, BLACK, &handipat_db, NULL, NULL); |
| 320 | |
| 321 | if (number_of_matches == 0) |
| 322 | return 0; |
| 323 | |
| 324 | /* Find the highest value among the matched patterns. */ |
| 325 | for (k = 0; k < number_of_matches; k++) |
| 326 | if (highest_value < handicap_matches[k].value) |
| 327 | highest_value = handicap_matches[k].value; |
| 328 | |
| 329 | /* Replace the values by 2^(value - highest_value + 10) and compute |
| 330 | * the sum of these values. Fractional values are discarded. |
| 331 | */ |
| 332 | for (k = 0; k < number_of_matches; k++) { |
| 333 | if (handicap_matches[k].value < highest_value - 10) |
| 334 | handicap_matches[k].value = 0; |
| 335 | else |
| 336 | handicap_matches[k].value = 1 << (handicap_matches[k].value |
| 337 | - highest_value + 10); |
| 338 | sum_values += handicap_matches[k].value; |
| 339 | } |
| 340 | |
| 341 | /* Pick a random number between 0 and sum_values. Don't bother with |
| 342 | * the fact that lower numbers will tend to be very slightly |
| 343 | * overrepresented. |
| 344 | */ |
| 345 | r = gg_rand() % sum_values; |
| 346 | |
| 347 | /* Find the chosen pattern. */ |
| 348 | for (k = 0; k < number_of_matches; k++) { |
| 349 | r -= handicap_matches[k].value; |
| 350 | if (r < 0) |
| 351 | break; |
| 352 | } |
| 353 | |
| 354 | /* Place handicap stones according to pattern k. */ |
| 355 | anchor = handicap_matches[k].anchor; |
| 356 | pattern = handicap_matches[k].pattern; |
| 357 | ll = handicap_matches[k].ll; |
| 358 | |
| 359 | /* Pick up the location of the move */ |
| 360 | move = AFFINE_TRANSFORM(pattern->move_offset, ll, anchor); |
| 361 | add_stone(move, BLACK); |
| 362 | remaining_handicap_stones--; |
| 363 | |
| 364 | /* Add stones at all '!' in the pattern. */ |
| 365 | for (k = 0; k < pattern->patlen; k++) { |
| 366 | if (pattern->patn[k].att == ATT_not) { |
| 367 | int pos = AFFINE_TRANSFORM(pattern->patn[k].offset, ll, anchor); |
| 368 | add_stone(pos, BLACK); |
| 369 | remaining_handicap_stones--; |
| 370 | } |
| 371 | } |
| 372 | |
| 373 | return 1; |
| 374 | } |
| 375 | |
| 376 | static void |
| 377 | free_handicap_callback(int anchor, int color, struct pattern *pattern, |
| 378 | int ll, void *data) |
| 379 | { |
| 380 | int r = -1; |
| 381 | int k; |
| 382 | int number_of_stones = 1; |
| 383 | |
| 384 | /* Pick up the location of the move */ |
| 385 | int move = AFFINE_TRANSFORM(pattern->move_offset, ll, anchor); |
| 386 | |
| 387 | UNUSED(data); |
| 388 | |
| 389 | /* Check how many stones are placed by the pattern. This must not be |
| 390 | * larger than the number of remaining handicap stones. |
| 391 | */ |
| 392 | for (k = 0; k < pattern->patlen; k++) { |
| 393 | if (pattern->patn[k].att == ATT_not) |
| 394 | number_of_stones++; |
| 395 | } |
| 396 | if (number_of_stones > remaining_handicap_stones) |
| 397 | return; |
| 398 | |
| 399 | /* If the pattern has a constraint, call the autohelper to see |
| 400 | * if the pattern must be rejected. |
| 401 | */ |
| 402 | if (pattern->autohelper_flag & HAVE_CONSTRAINT) { |
| 403 | if (!pattern->autohelper(ll, move, color, 0)) |
| 404 | return; |
| 405 | } |
| 406 | |
| 407 | if (number_of_matches < MAX_HANDICAP_MATCHES) { |
| 408 | r = number_of_matches; |
| 409 | number_of_matches++; |
| 410 | } |
| 411 | else { |
| 412 | int least_value = handicap_matches[0].value + 1; |
| 413 | for (k = 0; k < number_of_matches; k++) { |
| 414 | if (handicap_matches[k].value < least_value) { |
| 415 | r = k; |
| 416 | least_value = handicap_matches[k].value; |
| 417 | } |
| 418 | } |
| 419 | } |
| 420 | gg_assert(r >= 0 && r < MAX_HANDICAP_MATCHES); |
| 421 | handicap_matches[r].value = pattern->value; |
| 422 | handicap_matches[r].anchor = anchor; |
| 423 | handicap_matches[r].pattern = pattern; |
| 424 | handicap_matches[r].ll = ll; |
| 425 | } |
| 426 | |
| 427 | int |
| 428 | free_handicap_remaining_stones() |
| 429 | { |
| 430 | gg_assert(remaining_handicap_stones >= 0); |
| 431 | return remaining_handicap_stones; |
| 432 | } |
| 433 | |
| 434 | int |
| 435 | free_handicap_total_stones() |
| 436 | { |
| 437 | gg_assert(total_handicap_stones >= 0); |
| 438 | return total_handicap_stones; |
| 439 | } |
| 440 | |
| 441 | /* |
| 442 | * Local Variables: |
| 443 | * tab-width: 8 |
| 444 | * c-basic-offset: 2 |
| 445 | * End: |
| 446 | */ |