playout/moggy.c

   1 /* Playout policy by stochastically applying a fixed set of decision
   2  * rules in given order - modelled after the intelligent playouts
   3  * in the Mogo engine. */
   4
   5 #include <assert.h>
   6 #include <math.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9
  10 #define DEBUG
  11 #include "board.h"
  12 #include "debug.h"
  13 #include "joseki/base.h"
  14 #include "mq.h"
  15 #include "pattern3.h"
  16 #include "playout.h"
  17 #include "playout/moggy.h"
  18 #include "random.h"
  19 #include "tactics.h"
  20 #include "uct/prior.h"
  21
  22 #define PLDEBUGL(n) DEBUGL_(p->debug_level, n)
  23
  24 /* Whether to avoid capturing/atariing doomed groups (this is big
  25  * performance hit and may reduce playouts balance; it does increase
  26  * the strength, but not quite proportionally to the performance). */
  27 //#define NO_DOOMED_GROUPS
  28
  29
  30 /* Note that the context can be shared by multiple threads! */
  31
  32 struct moggy_policy {
  33         bool ladders, ladderassess, borderladders, assess_local;
  34         unsigned int lcapturerate, atarirate, capturerate, patternrate, korate, josekirate;
  35         unsigned int selfatarirate, alwaysccaprate;
  36         unsigned int fillboardtries;
  37         int koage;
  38         /* Whether to look for patterns around second-to-last move. */
  39         bool pattern2;
  40         /* Whether, when self-atari attempt is detected, to play the other
  41          * group's liberty if that is non-self-atari. */
  42         bool selfatari_other;
  43
  44         struct pattern3s patterns;
  45 };
  46
  47
  48 struct group_state {
  49         enum {
  50                 G_ATARI,
  51                 G_2LIB, /* Unused. */
  52                 G_SAFE /* Unused. */
  53         } status:2;
  54
  55         /* Below, we keep track of each trait for each |color_to_play */
  56         int capturable_ready:2; // is @capturable meaningful?
  57         int capturable:2;
  58
  59         int can_countercapture_ready:2;
  60         int can_countercapture:2;
  61 };
  62
  63 /* Cache of evaluation of various board features. */
  64 struct board_state {
  65         int bsize2;
  66         hash_t hash;
  67         struct group_state *groups; /* [board_size2()], indexed by group_t */
  68         unsigned char *groups_known; /* Bitmap of known groups. */
  69 };
  70
  71 /* Using board cache: this turns out to be actually a 10% slowdown,
  72  * since we reuse data in the cache only very little within single
  73  * move. */
  74 // #define CACHE_STATE
  75 /* Reusing board cache across moves if they are successive on the
  76  * board; only cache entries within cfg distance 2 of the last move
  77  * are cleared. */
  78 // #define PERSISTENT_STATE
  79
  80 #ifdef CACHE_STATE
  81 static __thread struct board_state *ss;
  82
  83 static bool
  84 board_state_reuse(struct board_state *s, struct board *b)
  85 {
  86         /* Decide how much of the board state we can reuse. */
  87         /* We do not cache ladder decisions, so we don't have
  88          * to worry about this. */
  89         coord_t c = b->last_move.coord;
  90
  91         if (unlikely(is_pass(c))) {
  92                 /* Passes don't change anything. */
  93                 return true;
  94         }
  95
  96         if (unlikely(board_at(b, c) == S_NONE)) {
  97                 /* Suicide is hopeless. */
  98                 return false;
  99         }
 100
 101         /* XXX: we can make some moves self-atari. */
 102
 103         if (neighbor_count_at(b, c, S_BLACK) + neighbor_count_at(b, c, S_WHITE) == 0) {
 104                 /* We are not taking off liberties of any other stones. */
 105                 return true;
 106         }
 107
 108         return false;
 109 }
 110
 111 static inline struct board_state *
 112 board_state_init(struct board *b)
 113 {
 114         if (ss) {
 115                 if (ss->bsize2 != board_size2(b)) {
 116                         free(ss->groups);
 117                         free(ss->groups_known);
 118                         free(ss); ss = NULL;
 119                 }
 120 #ifdef PERSISTENT_STATE
 121                 /* Only one stone added to the board, nothing removed. */
 122                 else if (ss->hash == (b->hash ^ hash_at(b, b->last_move.coord, b->last_move.color))) {
 123                         ss->hash = b->hash;
 124                         if (likely(board_state_reuse(ss, b)))
 125                                 return ss;
 126                 }
 127 #endif
 128         }
 129         if (!ss) {
 130                 ss = malloc2(sizeof(*ss));
 131                 ss->bsize2 = board_size2(b);
 132                 ss->groups = malloc2(board_size2(b) * sizeof(*ss->groups));
 133                 ss->groups_known = malloc2(board_size2(b) / 8 + 1);
 134         }
 135         ss->hash = b->hash;
 136         memset(ss->groups_known, 0, board_size2(b) / 8 + 1);
 137         return ss;
 138 }
 139
 140 #define group_is_known(s, g) (s->groups_known[g >> 3] & (1 << (g & 7)))
 141 #define group_set_known(s, g) (s->groups_known[g >> 3] |= (1 << (g & 7)))
 142 #define group_trait_ready(s, g, color, gstat, trait) do { \
 143         if (!group_is_known(s, g)) { \
 144                 memset(&s->groups[g], 0, sizeof(s->groups[g])); \
 145                 group_set_known(s, g); \
 146         } \
 147         s->groups[g].status = gstat; \
 148         s->groups[g].trait ## _ready |= color; \
 149 } while (0)
 150 #define group_trait_is_ready(s, g, color, trait) (s->groups[g].trait ## _ready & color)
 151 #define group_trait_set(s, g, color, trait, val) s->groups[g].trait = (s->groups[g].trait & ~color) | (!!val * color)
 152 #define group_trait_get(s, g, color, trait) (s->groups[g].trait & color)
 153
 154 #else
 155
 156 #define board_state_init(b) NULL
 157 #define group_is_known(s, g) false
 158 #define group_set_known(s, g)
 159 #define group_trait_ready(s, g, color, gstat, trait)
 160 #define group_trait_is_ready(s, g, color, trait) false
 161 #define group_trait_set(s, g, color, trait, val)
 162 #define group_trait_get(s, g, color, trait) false
 163 #endif
 164
 165
 166 static char moggy_patterns_src[][11] = {
 167         /* hane pattern - enclosing hane */
 168         "XOX"
 169         "..."
 170         "???",
 171         /* hane pattern - non-cutting hane */
 172         "XO."
 173         "..."
 174         "?.?",
 175         /* hane pattern - magari */
 176         "XO?"
 177         "X.."
 178         "x.?",
 179         /* hane pattern - thin hane */
 180         "XOO"
 181         "..."
 182         "?.?" "X",
 183         /* generic pattern - katatsuke or diagonal attachment; similar to magari */
 184         ".O."
 185         "X.."
 186         "...",
 187         /* cut1 pattern (kiri) - unprotected cut */
 188         "XO?"
 189         "O.o"
 190         "?o?",
 191         /* cut1 pattern (kiri) - peeped cut */
 192         "XO?"
 193         "O.X"
 194         "???",
 195         /* cut2 pattern (de) */
 196         "?X?"
 197         "O.O"
 198         "ooo",
 199         /* cut keima (not in Mogo) */
 200         "OX?"
 201         "o.O"
 202         "???", /* o?? has some pathological tsumego cases */
 203         /* side pattern - chase */
 204         "X.?"
 205         "O.?"
 206         "##?",
 207         /* side pattern - block side extension */
 208         "?X?"
 209         "x.O"
 210         "###",
 211         /* side pattern - sagari (SUSPICIOUS) */
 212         "?XO"
 213         "x.x" /* Mogo has "x.?" */
 214         "###" /* Mogo has "X" */,
 215         /* side pattern - throw-in (SUSPICIOUS) */
 216 #if 0
 217         "?OX"
 218         "o.O"
 219         "?##" "X",
 220 #endif
 221         /* side pattern - cut (SUSPICIOUS) */
 222         "?OX"
 223         "X.O"
 224         "###" /* Mogo has "X" */,
 225 };
 226 #define moggy_patterns_src_n sizeof(moggy_patterns_src) / sizeof(moggy_patterns_src[0])
 227
 228 static inline bool
 229 test_pattern3_here(struct playout_policy *p, struct board *b, struct move *m)
 230 {
 231         struct moggy_policy *pp = p->data;
 232         /* Check if 3x3 pattern is matched by given move... */
 233         if (!pattern3_move_here(&pp->patterns, b, m))
 234                 return false;
 235         /* ...and the move is not obviously stupid. */
 236         if (is_bad_selfatari(b, m->color, m->coord))
 237                 return false;
 238         /* Ladder moves are stupid. */
 239         group_t atari_neighbor = board_get_atari_neighbor(b, m->coord, m->color);
 240         if (atari_neighbor && is_ladder(b, m->coord, atari_neighbor, pp->borderladders, pp->ladders))
 241                 return false;
 242         return true;
 243 }
 244
 245 static void
 246 apply_pattern_here(struct playout_policy *p, struct board *b, coord_t c, enum stone color, struct move_queue *q)
 247 {
 248         struct move m2 = { .coord = c, .color = color };
 249         if (board_is_valid_move(b, &m2) && test_pattern3_here(p, b, &m2))
 250                 mq_add(q, c);
 251 }
 252
 253 /* Check if we match any pattern around given move (with the other color to play). */
 254 static coord_t
 255 apply_pattern(struct playout_policy *p, struct board *b, struct move *m, struct move *mm)
 256 {
 257         struct move_queue q;
 258         q.moves = 0;
 259
 260         /* Suicides do not make any patterns and confuse us. */
 261         if (board_at(b, m->coord) == S_NONE || board_at(b, m->coord) == S_OFFBOARD)
 262                 return pass;
 263
 264         foreach_8neighbor(b, m->coord) {
 265                 apply_pattern_here(p, b, c, stone_other(m->color), &q);
 266         } foreach_8neighbor_end;
 267
 268         if (mm) { /* Second move for pattern searching */
 269                 foreach_8neighbor(b, mm->coord) {
 270                         if (coord_is_8adjecent(m->coord, c, b))
 271                                 continue;
 272                         apply_pattern_here(p, b, c, stone_other(m->color), &q);
 273                 } foreach_8neighbor_end;
 274         }
 275
 276         if (PLDEBUGL(5))
 277                 mq_print(&q, b, "Pattern");
 278
 279         return mq_pick(&q);
 280 }
 281
 282
 283 static bool
 284 can_play_on_lib(struct playout_policy *p, struct board_state *s,
 285                 struct board *b, group_t g, enum stone to_play)
 286 {
 287         if (group_is_known(s, g) && group_trait_is_ready(s, g, to_play, capturable)) {
 288                 /* We have already seen this group. */
 289                 assert(s->groups[g].status == G_ATARI);
 290                 if (group_trait_get(s, g, to_play, capturable))
 291                         return true;
 292                 else
 293                         return false;
 294         }
 295
 296         /* Cache miss. Set up cache entry, default at capturable = false. */
 297         group_trait_ready(s, g, to_play, G_ATARI, capturable);
 298
 299         coord_t capture = board_group_info(b, g).lib[0];
 300         if (PLDEBUGL(6))
 301                 fprintf(stderr, "can capture group %d (%s)?\n",
 302                         g, coord2sstr(capture, b));
 303         /* Does playing on the liberty usefully capture the group? */
 304         if (board_is_valid_play(b, to_play, capture)
 305             && !is_bad_selfatari(b, to_play, capture)) {
 306                 group_trait_set(s, g, to_play, capturable, true);
 307                 return true;
 308         }
 309
 310         return false;
 311 }
 312
 313 /* For given position @c, decide if this is a group that is in danger from
 314  * @capturer and @to_play can do anything about it (play at the last
 315  * liberty to either capture or escape). */
 316 /* Note that @to_play is important; e.g. consider snapback, it's good
 317  * to play at the last liberty by attacker, but not defender. */
 318 static __attribute__((always_inline)) bool
 319 capturable_group(struct playout_policy *p, struct board_state *s,
 320                  struct board *b, enum stone capturer, coord_t c,
 321                  enum stone to_play)
 322 {
 323         group_t g = group_at(b, c);
 324         if (likely(board_at(b, c) != stone_other(capturer)
 325                    || board_group_info(b, g).libs > 1))
 326                 return false;
 327
 328         return can_play_on_lib(p, s, b, g, to_play);
 329 }
 330
 331 /* For given atari group @group owned by @owner, decide if @to_play
 332  * can save it / keep it in danger by dealing with one of the
 333  * neighboring groups. */
 334 static bool
 335 can_countercapture(struct playout_policy *p, struct board_state *s,
 336                    struct board *b, enum stone owner, group_t g,
 337                    enum stone to_play, struct move_queue *q)
 338 {
 339         if (b->clen < 2)
 340                 return false;
 341         if (group_is_known(s, g) && group_trait_is_ready(s, g, to_play, can_countercapture)) {
 342                 /* We have already seen this group. */
 343                 assert(s->groups[g].status == G_ATARI);
 344                 if (group_trait_get(s, g, to_play, can_countercapture)) {
 345                         if (q) { /* Scan for countercapture liberties. */
 346                                 goto scan;
 347                         }
 348                         return true;
 349                 } else {
 350                         return false;
 351                 }
 352         }
 353
 354         /* Cache miss. Set up cache entry, default at can_countercapture = true. */
 355         group_trait_ready(s, g, to_play, G_ATARI, can_countercapture);
 356         group_trait_set(s, g, to_play, can_countercapture, true);
 357
 358 scan:;
 359         unsigned int qmoves_prev = q ? q->moves : 0;
 360
 361         foreach_in_group(b, g) {
 362                 foreach_neighbor(b, c, {
 363                         if (!capturable_group(p, s, b, owner, c, to_play))
 364                                 continue;
 365
 366                         if (!q) {
 367                                 return true;
 368                         }
 369                         mq_add(q, board_group_info(b, group_at(b, c)).lib[0]);
 370                         mq_nodup(q);
 371                 });
 372         } foreach_in_group_end;
 373
 374         bool can = q ? q->moves > qmoves_prev : false;
 375         group_trait_set(s, g, to_play, can_countercapture, can);
 376         return can;
 377 }
 378
 379 #ifdef NO_DOOMED_GROUPS
 380 static bool
 381 can_be_rescued(struct playout_policy *p, struct board_state *s,
 382                struct board *b, group_t group, enum stone color)
 383 {
 384         /* Does playing on the liberty rescue the group? */
 385         if (can_play_on_lib(p, s, b, group, color))
 386                 return true;
 387
 388         /* Then, maybe we can capture one of our neighbors? */
 389         return can_countercapture(p, s, b, color, group, color, NULL);
 390 }
 391 #endif
 392
 393 /* ladder != NULL implies to always enqueue all relevant moves. */
 394 static void
 395 group_atari_check(struct playout_policy *p, struct board *b, group_t group, enum stone to_play,
 396                   struct move_queue *q, coord_t *ladder, struct board_state *s)
 397 {
 398         struct moggy_policy *pp = p->data;
 399         int qmoves_prev = q->moves;
 400
 401         /* We don't use @to_play almost anywhere since any moves here are good
 402          * for both defender and attacker. */
 403
 404         enum stone color = board_at(b, group_base(group));
 405         coord_t lib = board_group_info(b, group).lib[0];
 406
 407         assert(color != S_OFFBOARD && color != S_NONE);
 408         if (PLDEBUGL(5))
 409                 fprintf(stderr, "[%s] atariiiiiiiii %s of color %d\n",
 410                         coord2sstr(group, b), coord2sstr(lib, b), color);
 411         assert(board_at(b, lib) == S_NONE);
 412
 413         /* Can we capture some neighbor? */
 414         bool ccap = can_countercapture(p, s, b, color, group, to_play, q);
 415         if (ccap && !ladder && pp->alwaysccaprate > fast_random(100))
 416                 return;
 417
 418         /* Otherwise, do not save kos. */
 419         if (group_is_onestone(b, group)
 420             && neighbor_count_at(b, lib, color) + neighbor_count_at(b, lib, S_OFFBOARD) == 4)
 421                 return;
 422
 423         /* Do not suicide... */
 424         if (!can_play_on_lib(p, s, b, group, to_play))
 425                 return;
 426 #ifdef NO_DOOMED_GROUPS
 427         /* Do not remove group that cannot be saved by the opponent. */
 428         if (to_play != color && !can_be_rescued(p, s, b, group, color))
 429                 return;
 430 #endif
 431         if (PLDEBUGL(6))
 432                 fprintf(stderr, "...escape route valid\n");
 433
 434         /* ...or play out ladders. */
 435         if (is_ladder(b, lib, group, pp->borderladders, pp->ladders)) {
 436                 /* Sometimes we want to keep the ladder move in the
 437                  * queue in order to discourage it. */
 438                 if (!ladder)
 439                         return;
 440                 else
 441                         *ladder = lib;
 442         }
 443         if (PLDEBUGL(6))
 444                 fprintf(stderr, "...no ladder\n");
 445
 446         if (to_play != color) {
 447                 /* We are the attacker! In that case, throw away the moves
 448                  * that defend our groups, since we can capture the culprit. */
 449                 q->moves = qmoves_prev;
 450         }
 451
 452         mq_add(q, lib);
 453         mq_nodup(q);
 454 }
 455
 456 static coord_t
 457 joseki_check(struct playout_policy *p, struct board *b, enum stone to_play, struct board_state *s)
 458 {
 459         struct move_queue q;
 460         q.moves = 0;
 461
 462         for (int i = 0; i < 4; i++) {
 463                 hash_t h = b->qhash[i] & joseki_hash_mask;
 464                 coord_t *cc = joseki_pats[h].moves[to_play];
 465                 if (!cc) continue;
 466                 for (; !is_pass(*cc); cc++) {
 467                         if (coord_quadrant(*cc, b) != i)
 468                                 continue;
 469                         mq_add(&q, *cc);
 470                 }
 471         }
 472
 473         if (q.moves > 0) {
 474                 if (PLDEBUGL(5))
 475                         mq_print(&q, b, "Joseki");
 476                 return mq_pick(&q);
 477         }
 478         return pass;
 479 }
 480
 481 static coord_t
 482 global_atari_check(struct playout_policy *p, struct board *b, enum stone to_play, struct board_state *s)
 483 {
 484         struct move_queue q;
 485         q.moves = 0;
 486
 487         if (b->clen == 0)
 488                 return pass;
 489
 490         int g_base = fast_random(b->clen);
 491         for (int g = g_base; g < b->clen; g++) {
 492                 group_atari_check(p, b, group_at(b, group_base(b->c[g])), to_play, &q, NULL, s);
 493                 if (q.moves > 0) {
 494                         if (PLDEBUGL(5))
 495                                 mq_print(&q, b, "Global atari");
 496                         return mq_pick(&q);
 497                 }
 498         }
 499         for (int g = 0; g < g_base; g++) {
 500                 group_atari_check(p, b, group_at(b, group_base(b->c[g])), to_play, &q, NULL, s);
 501                 if (q.moves > 0) {
 502                         if (PLDEBUGL(5))
 503                                 mq_print(&q, b, "Global atari");
 504                         return mq_pick(&q);
 505                 }
 506         }
 507         return pass;
 508 }
 509
 510 static coord_t
 511 local_atari_check(struct playout_policy *p, struct board *b, struct move *m, struct board_state *s)
 512 {
 513         struct move_queue q;
 514         q.moves = 0;
 515
 516         /* Did the opponent play a self-atari? */
 517         if (board_group_info(b, group_at(b, m->coord)).libs == 1) {
 518                 group_atari_check(p, b, group_at(b, m->coord), stone_other(m->color), &q, NULL, s);
 519         }
 520
 521         foreach_neighbor(b, m->coord, {
 522                 group_t g = group_at(b, c);
 523                 if (!g || board_group_info(b, g).libs != 1)
 524                         continue;
 525                 group_atari_check(p, b, g, stone_other(m->color), &q, NULL, s);
 526         });
 527
 528         if (PLDEBUGL(5))
 529                 mq_print(&q, b, "Local atari");
 530
 531         return mq_pick(&q);
 532 }
 533
 534 static bool
 535 miai_2lib(struct board *b, group_t group, enum stone color)
 536 {
 537         bool can_connect = false, can_pull_out = false;
 538         /* We have miai if we can either connect on both libs,
 539          * or connect on one lib and escape on another. (Just
 540          * having two escape routes can be risky.) We must make
 541          * sure that we don't consider following as miai:
 542          * X X X O
 543          * X . . O
 544          * O O X O - left dot would be pull-out, right dot connect */
 545         foreach_neighbor(b, board_group_info(b, group).lib[0], {
 546                 enum stone cc = board_at(b, c);
 547                 if (cc == S_NONE && cc != board_at(b, board_group_info(b, group).lib[1])) {
 548                         can_pull_out = true;
 549                 } else if (cc != color) {
 550                         continue;
 551                 }
 552
 553                 group_t cg = group_at(b, c);
 554                 if (cg && cg != group && board_group_info(b, cg).libs > 1)
 555                         can_connect = true;
 556         });
 557         foreach_neighbor(b, board_group_info(b, group).lib[1], {
 558                 enum stone cc = board_at(b, c);
 559                 if (c == board_group_info(b, group).lib[0])
 560                         continue;
 561                 if (cc == S_NONE && can_connect) {
 562                         return true;
 563                 } else if (cc != color) {
 564                         continue;
 565                 }
 566
 567                 group_t cg = group_at(b, c);
 568                 if (cg && cg != group && board_group_info(b, cg).libs > 1)
 569                         return (can_connect || can_pull_out);
 570         });
 571         return false;
 572 }
 573
 574 static void
 575 check_group_atari(struct board *b, group_t group, enum stone owner,
 576                   enum stone to_play, struct move_queue *q)
 577 {
 578         for (int i = 0; i < 2; i++) {
 579                 coord_t lib = board_group_info(b, group).lib[i];
 580                 assert(board_at(b, lib) == S_NONE);
 581                 if (!board_is_valid_play(b, to_play, lib))
 582                         continue;
 583
 584                 /* Don't play at the spot if it is extremely short
 585                  * of liberties... */
 586                 /* XXX: This looks harmful, could significantly
 587                  * prefer atari to throwin:
 588                  *
 589                  * XXXOOOOOXX
 590                  * .OO.....OX
 591                  * XXXOOOOOOX */
 592 #if 0
 593                 if (neighbor_count_at(b, lib, stone_other(owner)) + immediate_liberty_count(b, lib) < 2)
 594                         continue;
 595 #endif
 596
 597                 /* If the move is too "lumpy", do not play it:
 598                  *
 599                  * #######
 600                  * ..O.X.X <- always play the left one!
 601                  * OXXXXXX */
 602                 if (neighbor_count_at(b, lib, stone_other(owner)) + neighbor_count_at(b, lib, S_OFFBOARD) == 3)
 603                         continue;
 604
 605 #ifdef NO_DOOMED_GROUPS
 606                 /* If the owner can't play at the spot, we don't want
 607                  * to bother either. */
 608                 if (is_bad_selfatari(b, owner, lib))
 609                         continue;
 610 #endif
 611
 612                 /* Of course we don't want to play bad selfatari
 613                  * ourselves, if we are the attacker... */
 614                 if (
 615 #ifdef NO_DOOMED_GROUPS
 616                     to_play != owner &&
 617 #endif
 618                     is_bad_selfatari(b, to_play, lib))
 619                         continue;
 620
 621                 /* Tasty! Crispy! Good! */
 622                 mq_add(q, lib);
 623                 mq_nodup(q);
 624         }
 625 }
 626
 627 static void
 628 group_2lib_check(struct playout_policy *p, struct board *b, group_t group, enum stone to_play,
 629                  struct move_queue *q, struct board_state *s)
 630 {
 631         enum stone color = board_at(b, group_base(group));
 632         assert(color != S_OFFBOARD && color != S_NONE);
 633
 634         if (PLDEBUGL(5))
 635                 fprintf(stderr, "[%s] 2lib check of color %d\n",
 636                         coord2sstr(group, b), color);
 637
 638         /* Do not try to atari groups that cannot be harmed. */
 639         if (miai_2lib(b, group, color))
 640                 return;
 641
 642         check_group_atari(b, group, color, to_play, q);
 643
 644         /* Can we counter-atari another group, if we are the defender? */
 645         if (to_play != color)
 646                 return;
 647         foreach_in_group(b, group) {
 648                 foreach_neighbor(b, c, {
 649                         if (board_at(b, c) != stone_other(color))
 650                                 continue;
 651                         group_t g2 = group_at(b, c);
 652                         if (board_group_info(b, g2).libs != 2)
 653                                 continue;
 654                         check_group_atari(b, g2, color, to_play, q);
 655                 });
 656         } foreach_in_group_end;
 657 }
 658
 659 static coord_t
 660 local_2lib_check(struct playout_policy *p, struct board *b, struct move *m, struct board_state *s)
 661 {
 662         struct move_queue q;
 663         q.moves = 0;
 664
 665         /* Does the opponent have just two liberties? */
 666         if (board_group_info(b, group_at(b, m->coord)).libs == 2) {
 667                 group_2lib_check(p, b, group_at(b, m->coord), stone_other(m->color), &q, s);
 668 #if 0
 669                 /* We always prefer to take off an enemy chain liberty
 670                  * before pulling out ourselves. */
 671                 /* XXX: We aren't guaranteed to return to that group
 672                  * later. */
 673                 if (q.moves)
 674                         return q.move[fast_random(q.moves)];
 675 #endif
 676         }
 677
 678         /* Then he took a third liberty from neighboring chain? */
 679         foreach_neighbor(b, m->coord, {
 680                 group_t g = group_at(b, c);
 681                 if (!g || board_group_info(b, g).libs != 2)
 682                         continue;
 683                 group_2lib_check(p, b, g, stone_other(m->color), &q, s);
 684         });
 685
 686         if (PLDEBUGL(5))
 687                 mq_print(&q, b, "Local 2lib");
 688
 689         return mq_pick(&q);
 690 }
 691
 692 coord_t
 693 playout_moggy_choose(struct playout_policy *p, struct board *b, enum stone to_play)
 694 {
 695         struct moggy_policy *pp = p->data;
 696         coord_t c;
 697
 698         struct board_state *s = board_state_init(b);
 699
 700         if (PLDEBUGL(5))
 701                 board_print(b, stderr);
 702
 703         /* Ko fight check */
 704         if (!is_pass(b->last_ko.coord) && is_pass(b->ko.coord)
 705             && b->moves - b->last_ko_age < pp->koage
 706             && pp->korate > fast_random(100)) {
 707                 if (board_is_valid_play(b, to_play, b->last_ko.coord)
 708                     && !is_bad_selfatari(b, to_play, b->last_ko.coord))
 709                         return b->last_ko.coord;
 710         }
 711
 712         /* Local checks */
 713         if (!is_pass(b->last_move.coord)) {
 714                 /* Local group in atari? */
 715                 if (pp->lcapturerate > fast_random(100)) {
 716                         c = local_atari_check(p, b, &b->last_move, s);
 717                         if (!is_pass(c))
 718                                 return c;
 719                 }
 720
 721                 /* Local group can be PUT in atari? */
 722                 if (pp->atarirate > fast_random(100)) {
 723                         c = local_2lib_check(p, b, &b->last_move, s);
 724                         if (!is_pass(c))
 725                                 return c;
 726                 }
 727
 728                 /* Check for patterns we know */
 729                 if (pp->patternrate > fast_random(100)) {
 730                         c = apply_pattern(p, b, &b->last_move,
 731                                           pp->pattern2 && b->last_move2.coord >= 0 ? &b->last_move2 : NULL);
 732                         if (!is_pass(c))
 733                                 return c;
 734                 }
 735         }
 736
 737         /* Global checks */
 738
 739         /* Any groups in atari? */
 740         if (pp->capturerate > fast_random(100)) {
 741                 c = global_atari_check(p, b, to_play, s);
 742                 if (!is_pass(c))
 743                         return c;
 744         }
 745
 746         /* Joseki moves? */
 747         if (pp->josekirate > fast_random(100)) {
 748                 c = joseki_check(p, b, to_play, s);
 749                 if (!is_pass(c))
 750                         return c;
 751         }
 752
 753         /* Fill board */
 754         unsigned int fbtries = b->flen / 8;
 755         for (unsigned int i = 0; i < (fbtries < pp->fillboardtries ? fbtries : pp->fillboardtries); i++) {
 756                 coord_t coord = b->f[fast_random(b->flen)];
 757                 if (immediate_liberty_count(b, coord) != 4)
 758                         continue;
 759                 foreach_diag_neighbor(b, coord) {
 760                         if (board_at(b, c) != S_NONE)
 761                                 goto next_try;
 762                 } foreach_diag_neighbor_end;
 763                 return coord;
 764 next_try:;
 765         }
 766
 767         return pass;
 768 }
 769
 770
 771 static coord_t
 772 selfatari_cousin(struct board *b, enum stone color, coord_t coord)
 773 {
 774         group_t groups[4]; int groups_n = 0;
 775         foreach_neighbor(b, coord, {
 776                 enum stone s = board_at(b, c);
 777                 if (s != color) continue;
 778                 group_t g = group_at(b, c);
 779                 if (board_group_info(b, g).libs == 2)
 780                         groups[groups_n++] = g;
 781         });
 782
 783         if (!groups_n)
 784                 return pass;
 785         group_t group = groups[fast_random(groups_n)];
 786
 787         coord_t lib2 = board_group_other_lib(b, group, coord);
 788         if (is_bad_selfatari(b, color, lib2))
 789                 return pass;
 790         return lib2;
 791 }
 792
 793 static int
 794 assess_local_bonus(struct playout_policy *p, struct board *board, coord_t a, coord_t b, int games)
 795 {
 796         struct moggy_policy *pp = p->data;
 797         if (!pp->assess_local)
 798                 return games;
 799
 800         int dx = abs(coord_x(a, board) - coord_x(b, board));
 801         int dy = abs(coord_y(a, board) - coord_y(b, board));
 802         /* adjecent move, directly or diagonally? */
 803         if (dx + dy <= 1 + (dx && dy))
 804                 return games;
 805         else
 806                 return games / 2;
 807 }
 808
 809 void
 810 playout_moggy_assess_group(struct playout_policy *p, struct prior_map *map, group_t g, int games,
 811                            struct board_state *s)
 812 {
 813         struct moggy_policy *pp = p->data;
 814         struct board *b = map->b;
 815         struct move_queue q; q.moves = 0;
 816
 817         if (board_group_info(b, g).libs > 2)
 818                 return;
 819
 820         if (PLDEBUGL(5)) {
 821                 fprintf(stderr, "ASSESS of group %s:\n", coord2sstr(g, b));
 822                 board_print(b, stderr);
 823         }
 824
 825         if (board_group_info(b, g).libs == 2) {
 826                 if (!pp->atarirate)
 827                         return;
 828                 group_2lib_check(p, b, g, map->to_play, &q, s);
 829                 while (q.moves--) {
 830                         coord_t coord = q.move[q.moves];
 831                         if (PLDEBUGL(5))
 832                                 fprintf(stderr, "1.0: 2lib %s\n", coord2sstr(coord, b));
 833                         int assess = assess_local_bonus(p, b, b->last_move.coord, coord, games) / 2;
 834                         add_prior_value(map, coord, 1, assess);
 835                 }
 836                 return;
 837         }
 838
 839         /* This group, sir, is in atari! */
 840
 841         if (!pp->capturerate && !pp->lcapturerate && !pp->ladderassess)
 842                 return;
 843
 844         coord_t ladder = pass;
 845         group_atari_check(p, b, g, map->to_play, &q, &ladder, s);
 846         while (q.moves--) {
 847                 coord_t coord = q.move[q.moves];
 848
 849                 /* _Never_ play here if this move plays out
 850                  * a caught ladder. */
 851                 if (coord == ladder && !board_playing_ko_threat(b)) {
 852                         /* Note that the opposite is not guarded against;
 853                          * we do not advise against capturing a laddered
 854                          * group (but we don't encourage it either). Such
 855                          * a move can simplify tactical situations if we
 856                          * can afford it. */
 857                         if (!pp->ladderassess || map->to_play != board_at(b, g))
 858                                 continue;
 859                         /* FIXME: We give the malus even if this move
 860                          * captures another group. */
 861                         if (PLDEBUGL(5))
 862                                 fprintf(stderr, "0.0: ladder %s\n", coord2sstr(coord, b));
 863                         add_prior_value(map, coord, 0, games);
 864                         continue;
 865                 }
 866
 867                 if (!pp->capturerate && !pp->lcapturerate)
 868                         continue;
 869
 870                 if (PLDEBUGL(5))
 871                         fprintf(stderr, "1.0: atari %s\n", coord2sstr(coord, b));
 872                 int assess = assess_local_bonus(p, b, b->last_move.coord, coord, games) * 2;
 873                 add_prior_value(map, coord, 1, assess);
 874         }
 875 }
 876
 877 void
 878 playout_moggy_assess_one(struct playout_policy *p, struct prior_map *map, coord_t coord, int games)
 879 {
 880         struct moggy_policy *pp = p->data;
 881         struct board *b = map->b;
 882
 883         if (PLDEBUGL(5)) {
 884                 fprintf(stderr, "ASSESS of move %s:\n", coord2sstr(coord, b));
 885                 board_print(b, stderr);
 886         }
 887
 888         /* Is this move a self-atari? */
 889         if (pp->selfatarirate) {
 890                 if (!board_playing_ko_threat(b) && is_bad_selfatari(b, map->to_play, coord)) {
 891                         if (PLDEBUGL(5))
 892                                 fprintf(stderr, "0.0: self-atari\n");
 893                         add_prior_value(map, coord, 0, games);
 894                         if (!pp->selfatari_other)
 895                                 return;
 896                         /* If we can play on the other liberty of the
 897                          * endangered group, do! */
 898                         coord = selfatari_cousin(b, map->to_play, coord);
 899                         if (is_pass(coord))
 900                                 return;
 901                         if (PLDEBUGL(5))
 902                                 fprintf(stderr, "1.0: self-atari redirect %s\n", coord2sstr(coord, b));
 903                         add_prior_value(map, coord, 1.0, games);
 904                         return;
 905                 }
 906         }
 907
 908         /* Pattern check */
 909         if (pp->patternrate) {
 910                 struct move m = { .color = map->to_play, .coord = coord };
 911                 if (test_pattern3_here(p, b, &m)) {
 912                         if (PLDEBUGL(5))
 913                                 fprintf(stderr, "1.0: pattern\n");
 914                         int assess = assess_local_bonus(p, b, b->last_move.coord, coord, games);
 915                         add_prior_value(map, coord, 1, assess);
 916                 }
 917         }
 918
 919         return;
 920 }
 921
 922 void
 923 playout_moggy_assess(struct playout_policy *p, struct prior_map *map, int games)
 924 {
 925         struct moggy_policy *pp = p->data;
 926
 927         struct board_state *s = board_state_init(map->b);
 928
 929         /* First, go through all endangered groups. */
 930         if (pp->lcapturerate || pp->capturerate || pp->atarirate || pp->ladderassess)
 931                 for (group_t g = 1; g < board_size2(map->b); g++)
 932                         if (group_at(map->b, g) == g)
 933                                 playout_moggy_assess_group(p, map, g, games, s);
 934
 935         /* Then, assess individual moves. */
 936         if (!pp->patternrate && !pp->selfatarirate)
 937                 return;
 938         foreach_free_point(map->b) {
 939                 if (map->consider[c])
 940                         playout_moggy_assess_one(p, map, c, games);
 941         } foreach_free_point_end;
 942 }
 943
 944 bool
 945 playout_moggy_permit(struct playout_policy *p, struct board *b, struct move *m)
 946 {
 947         struct moggy_policy *pp = p->data;
 948
 949         /* The idea is simple for now - never allow self-atari moves.
 950          * They suck in general, but this also permits us to actually
 951          * handle seki in the playout stage. */
 952
 953         if (fast_random(100) >= pp->selfatarirate) {
 954                 if (PLDEBUGL(5))
 955                         fprintf(stderr, "skipping sar test\n");
 956                 return true;
 957         }
 958         bool selfatari = is_bad_selfatari(b, m->color, m->coord);
 959         if (selfatari) {
 960                 if (PLDEBUGL(5))
 961                         fprintf(stderr, "__ Prohibiting self-atari %s %s\n",
 962                                 stone2str(m->color), coord2sstr(m->coord, b));
 963                 if (pp->selfatari_other) {
 964                         /* Ok, try the other liberty of the atari'd group. */
 965                         coord_t c = selfatari_cousin(b, m->color, m->coord);
 966                         if (is_pass(c)) return false;
 967                         if (PLDEBUGL(5))
 968                                 fprintf(stderr, "___ Redirecting to other lib %s\n",
 969                                         coord2sstr(c, b));
 970                         m->coord = c;
 971                         return true;
 972                 }
 973                 return false;
 974         }
 975         return true;
 976 }
 977
 978
 979 struct playout_policy *
 980 playout_moggy_init(char *arg, struct board *b)
 981 {
 982         struct playout_policy *p = calloc2(1, sizeof(*p));
 983         struct moggy_policy *pp = calloc2(1, sizeof(*pp));
 984         p->data = pp;
 985         p->choose = playout_moggy_choose;
 986         p->assess = playout_moggy_assess;
 987         p->permit = playout_moggy_permit;
 988
 989         int rate = 90;
 990
 991         pp->lcapturerate = pp->atarirate = pp->capturerate = pp->patternrate = pp->selfatarirate
 992                         = -1U;
 993         pp->korate = 0; pp->koage = 4;
 994         pp->alwaysccaprate = 0;
 995         pp->josekirate = 0;
 996         pp->ladders = pp->borderladders = true;
 997         pp->ladderassess = true;
 998
 999         if (arg) {
1000                 char *optspec, *next = arg;
1001                 while (*next) {
1002                         optspec = next;
1003                         next += strcspn(next, ":");
1004                         if (*next) { *next++ = 0; } else { *next = 0; }
1005
1006                         char *optname = optspec;
1007                         char *optval = strchr(optspec, '=');
1008                         if (optval) *optval++ = 0;
1009
1010                         if (!strcasecmp(optname, "lcapturerate") && optval) {
1011                                 pp->lcapturerate = atoi(optval);
1012                         } else if (!strcasecmp(optname, "atarirate") && optval) {
1013                                 pp->atarirate = atoi(optval);
1014                         } else if (!strcasecmp(optname, "capturerate") && optval) {
1015                                 pp->capturerate = atoi(optval);
1016                         } else if (!strcasecmp(optname, "patternrate") && optval) {
1017                                 pp->patternrate = atoi(optval);
1018                         } else if (!strcasecmp(optname, "selfatarirate") && optval) {
1019                                 pp->selfatarirate = atoi(optval);
1020                         } else if (!strcasecmp(optname, "korate") && optval) {
1021                                 pp->korate = atoi(optval);
1022                         } else if (!strcasecmp(optname, "josekirate") && optval) {
1023                                 pp->josekirate = atoi(optval);
1024                         } else if (!strcasecmp(optname, "alwaysccaprate") && optval) {
1025                                 pp->alwaysccaprate = atoi(optval);
1026                         } else if (!strcasecmp(optname, "rate") && optval) {
1027                                 rate = atoi(optval);
1028                         } else if (!strcasecmp(optname, "fillboardtries")) {
1029                                 pp->fillboardtries = atoi(optval);
1030                         } else if (!strcasecmp(optname, "koage") && optval) {
1031                                 pp->koage = atoi(optval);
1032                         } else if (!strcasecmp(optname, "ladders")) {
1033                                 pp->ladders = optval && *optval == '0' ? false : true;
1034                         } else if (!strcasecmp(optname, "borderladders")) {
1035                                 pp->borderladders = optval && *optval == '0' ? false : true;
1036                         } else if (!strcasecmp(optname, "ladderassess")) {
1037                                 pp->ladderassess = optval && *optval == '0' ? false : true;
1038                         } else if (!strcasecmp(optname, "assess_local")) {
1039                                 pp->assess_local = optval && *optval == '0' ? false : true;
1040                         } else if (!strcasecmp(optname, "pattern2")) {
1041                                 pp->pattern2 = optval && *optval == '0' ? false : true;
1042                         } else if (!strcasecmp(optname, "selfatari_other")) {
1043                                 pp->selfatari_other = optval && *optval == '0' ? false : true;
1044                         } else {
1045                                 fprintf(stderr, "playout-moggy: Invalid policy argument %s or missing value\n", optname);
1046                                 exit(1);
1047                         }
1048                 }
1049         }
1050         if (pp->lcapturerate == -1U) pp->lcapturerate = rate;
1051         if (pp->atarirate == -1U) pp->atarirate = rate;
1052         if (pp->capturerate == -1U) pp->capturerate = rate;
1053         if (pp->patternrate == -1U) pp->patternrate = rate;
1054         if (pp->selfatarirate == -1U) pp->selfatarirate = rate;
1055         if (pp->korate == -1U) pp->korate = rate;
1056         if (pp->josekirate == -1U) pp->josekirate = rate;
1057         if (pp->alwaysccaprate == -1U) pp->alwaysccaprate = rate;
1058
1059         pattern3s_init(&pp->patterns, moggy_patterns_src, moggy_patterns_src_n);
1060
1061         return p;
1062 }