patternsp.c

   1 #define DEBUG
   2 #include <assert.h>
   3 #include <ctype.h>
   4 #include <inttypes.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7
   8 #include "board.h"
   9 #include "debug.h"
  10 #include "pattern.h"
  11 #include "patternsp.h"
  12 #include "tactics.h"
  13
  14 /* Mapping from point sequence to coordinate offsets (to determine
  15  * coordinates relative to pattern center). The array is ordered
  16  * in the gridcular metric order so that we can go through it
  17  * and incrementally match spatial features in nested circles.
  18  * Within one circle, coordinates are ordered by rows to keep
  19  * good cache behavior. */
  20 struct ptcoord ptcoords[MAX_PATTERN_AREA];
  21
  22 /* For each radius, starting index in ptcoords[]. */
  23 int ptind[MAX_PATTERN_DIST + 2];
  24
  25 /* ptcoords[], ptind[] setup */
  26 static void
  27 ptcoords_init(void)
  28 {
  29         int i = 0; /* Indexing ptcoords[] */
  30
  31         /* First, center point. */
  32         ptind[0] = ptind[1] = 0;
  33         ptcoords[i].x = ptcoords[i].y = 0; i++;
  34
  35         for (int d = 2; d <= MAX_PATTERN_DIST; d++) {
  36                 ptind[d] = i;
  37                 /* For each y, examine all integer solutions
  38                  * of d = |x| + |y| + max(|x|, |y|). */
  39                 /* TODO: (Stern, 2006) uses a hand-modified
  40                  * circles that are finer for small d. */
  41                 for (short y = d / 2; y >= 0; y--) {
  42                         short x;
  43                         if (y > d / 3) {
  44                                 /* max(|x|, |y|) = |y|, non-zero x */
  45                                 x = d - y * 2;
  46                                 if (x + y * 2 != d) continue;
  47                         } else {
  48                                 /* max(|x|, |y|) = |x| */
  49                                 /* Or, max(|x|, |y|) = |y| and x is zero */
  50                                 x = (d - y) / 2;
  51                                 if (x * 2 + y != d) continue;
  52                         }
  53
  54                         assert((x > y ? x : y) + x + y == d);
  55
  56                         ptcoords[i].x = x; ptcoords[i].y = y; i++;
  57                         if (x != 0) { ptcoords[i].x = -x; ptcoords[i].y = y; i++; }
  58                         if (y != 0) { ptcoords[i].x = x; ptcoords[i].y = -y; i++; }
  59                         if (x != 0 && y != 0) { ptcoords[i].x = -x; ptcoords[i].y = -y; i++; }
  60                 }
  61         }
  62         ptind[MAX_PATTERN_DIST + 1] = i;
  63
  64 #if 0
  65         for (int d = 0; d <= MAX_PATTERN_DIST; d++) {
  66                 fprintf(stderr, "d=%d (%d) ", d, ptind[d]);
  67                 for (int j = ptind[d]; j < ptind[d + 1]; j++) {
  68                         fprintf(stderr, "%d,%d ", ptcoords[j].x, ptcoords[j].y);
  69                 }
  70                 fprintf(stderr, "\n");
  71         }
  72 #endif
  73 }
  74
  75
  76 /* Zobrist hashes used for points in patterns. */
  77 hash_t pthashes[PTH__ROTATIONS][MAX_PATTERN_AREA][S_MAX];
  78
  79 static void
  80 pthashes_init(void)
  81 {
  82         /* We need fixed hashes for all pattern-relative in
  83          * all pattern users! This is a simple way to generate
  84          * hopefully good ones. Park-Miller powa. :) */
  85
  86         /* We create a virtual board (centered at the sequence start),
  87          * plant the hashes there, then pick them up into the sequence
  88          * with correct coordinates. It would be possible to generate
  89          * the sequence point hashes directly, but the rotations would
  90          * make for enormous headaches. */
  91         hash_t pthboard[MAX_PATTERN_AREA][4];
  92         int pthbc = MAX_PATTERN_AREA / 2; // tengen coord
  93
  94         /* The magic numbers are tuned for minimal collisions. */
  95         hash_t h = 0x313131;
  96         for (int i = 0; i < MAX_PATTERN_AREA; i++) {
  97                 pthboard[i][S_NONE] = (h = h * 16803 - 7);
  98                 pthboard[i][S_BLACK] = (h = h * 16805 + 7);
  99                 pthboard[i][S_WHITE] = (h = h * 16807 + 3);
 100                 pthboard[i][S_OFFBOARD] = (h = h * 16809 - 3);
 101         }
 102
 103         /* Virtual board with hashes created, now fill
 104          * pthashes[] with hashes for points in actual
 105          * sequences, also considering various rotations. */
 106 #define PTH_VMIRROR     1
 107 #define PTH_HMIRROR     2
 108 #define PTH_90ROT       4
 109         for (int r = 0; r < PTH__ROTATIONS; r++) {
 110                 for (int i = 0; i < MAX_PATTERN_AREA; i++) {
 111                         /* Rotate appropriately. */
 112                         int rx = ptcoords[i].x;
 113                         int ry = ptcoords[i].y;
 114                         if (r & PTH_VMIRROR) ry = -ry;
 115                         if (r & PTH_HMIRROR) rx = -rx;
 116                         if (r & PTH_90ROT) {
 117                                 int rs = rx; rx = -ry; ry = rs;
 118                         }
 119                         int bi = pthbc + ry * MAX_PATTERN_DIST + rx;
 120
 121                         /* Copy info. */
 122                         pthashes[r][i][S_NONE] = pthboard[bi][S_NONE];
 123                         pthashes[r][i][S_BLACK] = pthboard[bi][S_BLACK];
 124                         pthashes[r][i][S_WHITE] = pthboard[bi][S_WHITE];
 125                         pthashes[r][i][S_OFFBOARD] = pthboard[bi][S_OFFBOARD];
 126                 }
 127         }
 128 }
 129
 130 static void __attribute__((constructor))
 131 spatial_init(void)
 132 {
 133         /* Initialization of various static data structures for
 134          * fast pattern processing. */
 135         ptcoords_init();
 136         pthashes_init();
 137 }
 138
 139 inline hash_t
 140 spatial_hash(int rotation, struct spatial *s)
 141 {
 142         hash_t h = 0;
 143         for (int i = 0; i < ptind[s->dist + 1]; i++) {
 144                 h ^= pthashes[rotation][i][spatial_point_at(*s, i)];
 145         }
 146         return h & spatial_hash_mask;
 147 }
 148
 149 char *
 150 spatial2str(struct spatial *s)
 151 {
 152         static char buf[1024];
 153         for (int i = 0; i < ptind[s->dist + 1]; i++) {
 154                 buf[i] = stone2char(spatial_point_at(*s, i));
 155         }
 156         buf[ptind[s->dist + 1]] = 0;
 157         return buf;
 158 }
 159
 160 void
 161 spatial_from_board(struct pattern_config *pc, struct spatial *s,
 162                    struct board *b, struct move *m)
 163 {
 164         assert(pc->spat_min > 0);
 165
 166         /* We record all spatial patterns black-to-play; simply
 167          * reverse all colors if we are white-to-play. */
 168         static enum stone bt_black[4] = { S_NONE, S_BLACK, S_WHITE, S_OFFBOARD };
 169         static enum stone bt_white[4] = { S_NONE, S_WHITE, S_BLACK, S_OFFBOARD };
 170         enum stone (*bt)[4] = m->color == S_WHITE ? &bt_white : &bt_black;
 171
 172         memset(s, 0, sizeof(*s));
 173         for (int j = 0; j < ptind[pc->spat_max + 1]; j++) {
 174                 ptcoords_at(x, y, m->coord, b, j);
 175                 s->points[j / 4] |= (*bt)[board_atxy(b, x, y)] << ((j % 4) * 2);
 176         }
 177         s->dist = pc->spat_max;
 178 }
 179
 180 /* Compare two spatials, allowing for differences up to isomorphism.
 181  * True means the spatials are equivalent. */
 182 static bool
 183 spatial_cmp(struct spatial *s1, struct spatial *s2)
 184 {
 185         /* Quick preliminary check. */
 186         if (s1->dist != s2->dist)
 187                 return false;
 188
 189         /* We could create complex transposition tables, but it seems most
 190          * foolproof to just check if the sets of rotation hashes are the
 191          * same for both. */
 192         hash_t s1r[PTH__ROTATIONS];
 193         for (int r = 0; r < PTH__ROTATIONS; r++)
 194                 s1r[r] = spatial_hash(r, s1);
 195         for (int r = 0; r < PTH__ROTATIONS; r++) {
 196                 hash_t s2r = spatial_hash(r, s2);
 197                 for (int p = 0; p < PTH__ROTATIONS; p++)
 198                         if (s2r == s1r[p])
 199                                 goto found_rot;
 200                 /* Rotation hash s2r does not correspond to s1r. */
 201                 return false;
 202 found_rot:;
 203         }
 204
 205         /* All rotation hashes of s2 occur in s1. Hopefully that
 206          * indicates something. */
 207         return true;
 208 }
 209
 210
 211 /* Spatial dict manipulation. */
 212
 213 static int
 214 spatial_dict_addc(struct spatial_dict *dict, struct spatial *s)
 215 {
 216         /* Allocate space in 1024 blocks. */
 217 #define SPATIALS_ALLOC 1024
 218         if (!(dict->nspatials % SPATIALS_ALLOC)) {
 219                 dict->spatials = realloc(dict->spatials,
 220                                 (dict->nspatials + SPATIALS_ALLOC)
 221                                 * sizeof(*dict->spatials));
 222         }
 223         dict->spatials[dict->nspatials] = *s;
 224         return dict->nspatials++;
 225 }
 226
 227 static bool
 228 spatial_dict_addh(struct spatial_dict *dict, hash_t hash, int id)
 229 {
 230         if (dict->hash[hash] && dict->hash[hash] != id)
 231                 dict->collisions++;
 232         dict->hash[hash] = id;
 233         return true;
 234 }
 235
 236 /* Spatial dictionary file format:
 237  * /^#/ - comments
 238  * INDEX RADIUS STONES HASH...
 239  * INDEX: index in the spatial table
 240  * RADIUS: @d of the pattern
 241  * STONES: string of ".XO#" chars
 242  * HASH...: space-separated 18bit hash-table indices for the pattern */
 243
 244 static void
 245 spatial_dict_read(struct spatial_dict *dict, char *buf)
 246 {
 247         /* XXX: We trust the data. Bad data will crash us. */
 248         char *bufp = buf;
 249
 250         int index, radius;
 251         index = strtol(bufp, &bufp, 10);
 252         radius = strtol(bufp, &bufp, 10);
 253         while (isspace(*bufp)) bufp++;
 254
 255         /* Load the stone configuration. */
 256         struct spatial s = { .dist = radius };
 257         int sl = 0;
 258         while (!isspace(*bufp)) {
 259                 s.points[sl / 4] |= char2stone(*bufp++) << ((sl % 4)*2);
 260                 sl++;
 261         }
 262         while (isspace(*bufp)) bufp++;
 263
 264         /* Sanity check. */
 265         if (sl != ptind[s.dist + 1]) {
 266                 fprintf(stderr, "Spatial dictionary: Invalid number of stones (%d != %d) on this line: %s\n",
 267                         sl, ptind[radius + 1] - 1, buf);
 268                 exit(EXIT_FAILURE);
 269         }
 270
 271         /* Add to collection. */
 272         int id = spatial_dict_addc(dict, &s);
 273
 274         /* Add to specified hash places. */
 275         while (*bufp) {
 276                 int hash = strtol(bufp, &bufp, 16);
 277                 while (isspace(*bufp)) bufp++;
 278                 spatial_dict_addh(dict, hash & spatial_hash_mask, id);
 279         }
 280 }
 281
 282 void
 283 spatial_write(struct spatial_dict *dict, struct spatial *s, int id, FILE *f)
 284 {
 285         fprintf(f, "%d %d ", id, s->dist);
 286         fputs(spatial2str(s), f);
 287         for (int r = 0; r < PTH__ROTATIONS; r++) {
 288                 hash_t rhash = spatial_hash(r, s);
 289                 int id2 = dict->hash[rhash];
 290                 if (id2 != id) {
 291                         /* This hash does not belong to us. Decide whether
 292                          * we or the current owner is better owner. */
 293                         /* TODO: Compare also # of patternscan encounters? */
 294                         struct spatial *s2 = &dict->spatials[id2];
 295                         if (s2->dist < s->dist)
 296                                 continue;
 297                         if (s2->dist == s->dist && id2 < id)
 298                                 continue;
 299                 }
 300                 fprintf(f, " %"PRIhash"", spatial_hash(r, s));
 301         }
 302         fputc('\n', f);
 303 }
 304
 305 static void
 306 spatial_dict_load(struct spatial_dict *dict, FILE *f)
 307 {
 308         char buf[1024];
 309         while (fgets(buf, sizeof(buf), f)) {
 310                 if (buf[0] == '#') continue;
 311                 spatial_dict_read(dict, buf);
 312         }
 313 }
 314
 315 void
 316 spatial_dict_writeinfo(struct spatial_dict *dict, FILE *f)
 317 {
 318         /* New file. First, create a comment describing order
 319          * of points in the array. This is just for purposes
 320          * of external tools, Pachi never interprets it itself. */
 321         fprintf(f, "# Pachi spatial patterns dictionary v1.0 maxdist %d\n",
 322                 MAX_PATTERN_DIST);
 323         for (int d = 0; d <= MAX_PATTERN_DIST; d++) {
 324                 fprintf(f, "# Point order: d=%d ", d);
 325                 for (int j = ptind[d]; j < ptind[d + 1]; j++) {
 326                         fprintf(f, "%d,%d ", ptcoords[j].x, ptcoords[j].y);
 327                 }
 328                 fprintf(f, "\n");
 329         }
 330 }
 331
 332 const char *spatial_dict_filename = "patterns.spat";
 333 struct spatial_dict *
 334 spatial_dict_init(bool will_append)
 335 {
 336         FILE *f = fopen(spatial_dict_filename, "r");
 337         if (!f && !will_append) {
 338                 if (DEBUGL(1))
 339                         fprintf(stderr, "No spatial dictionary, will not match spatial pattern features.\n");
 340                 return NULL;
 341         }
 342
 343         struct spatial_dict *dict = calloc(1, sizeof(*dict));
 344         /* We create a dummy record for index 0 that we will
 345          * never reference. This is so that hash value 0 can
 346          * represent "no value". */
 347         struct spatial dummy = { .dist = 0 };
 348         spatial_dict_addc(dict, &dummy);
 349
 350         if (f) {
 351                 spatial_dict_load(dict, f);
 352                 fclose(f); f = NULL;
 353         } else {
 354                 assert(will_append);
 355         }
 356
 357         return dict;
 358 }
 359
 360 int
 361 spatial_dict_put(struct spatial_dict *dict, struct spatial *s, hash_t h)
 362 {
 363         /* We avoid spatial_dict_get() here, since we want to ignore radius
 364          * differences - we have custom collision detection. */
 365         int id = dict->hash[h];
 366         if (id > 0) {
 367                 /* Is this the same or isomorphous spatial? */
 368                 if (spatial_cmp(s, &dict->spatials[id]))
 369                         return id;
 370
 371                 /* Look a bit harder - perhaps one of our rotations still
 372                  * points at the correct spatial. */
 373                 for (int r = 0; r < PTH__ROTATIONS; r++) {
 374                         hash_t rhash = spatial_hash(r, s);
 375                         int rid = dict->hash[rhash];
 376                         /* No match means we definitely aren't stored yet. */
 377                         if (!rid)
 378                                 break;
 379                         if (id != rid && spatial_cmp(s, &dict->spatials[rid])) {
 380                                 /* Yay, this is us! */
 381                                 if (DEBUGL(3))
 382                                         fprintf(stderr, "Repeated collision %d vs %d\n", id, rid);
 383                                 id = rid;
 384                                 /* Point the hashes back to us. */
 385                                 goto hash_store;
 386                         }
 387                 }
 388
 389                 if (DEBUGL(1))
 390                         fprintf(stderr, "Collision %d vs %d\n", id, dict->nspatials);
 391                 id = 0;
 392                 /* dict->collisions++; gets done by addh */
 393         }
 394
 395         /* Add new pattern! */
 396         id = spatial_dict_addc(dict, s);
 397         if (DEBUGL(4)) {
 398                 fprintf(stderr, "new spat %d(%d) %s <%"PRIhash"> ", id, s->dist, spatial2str(s), h);
 399                 for (int r = 0; r < 8; r++)
 400                         fprintf(stderr,"[%"PRIhash"] ", spatial_hash(r, s));
 401                 fprintf(stderr, "\n");
 402         }
 403
 404         /* Store new pattern in the hash. */
 405 hash_store:
 406         for (int r = 0; r < PTH__ROTATIONS; r++)
 407                 spatial_dict_addh(dict, spatial_hash(r, s), id);
 408
 409         return id;
 410 }
 411
 412
 413 /** Pattern3 helpers */
 414
 415 /* XXX: We have hard-coded this point order:
 416  * # Point order: d=1 0,0
 417  * # Point order: d=2 0,1 0,-1 1,0 -1,0
 418  * # Point order: d=3 1,1 -1,1 1,-1 -1,-1
 419  */
 420 /* p3bits describe location of given point in the
 421  * pattern3 hash word. */
 422 static const int p3bits[] = { -1,  1, 6, 3, 4,  0, 2, 5, 7 };
 423
 424
 425 static hash_t
 426 pattern3_to_spatial(int r, int pat3)
 427 {
 428         hash_t h = pthashes[r][0][S_NONE];
 429         for (int i = 1; i < 9; i++)
 430                 h ^= pthashes[r][i][(pat3 >> (p3bits[i] * 2)) & 0x3];
 431         return h & spatial_hash_mask;
 432 }
 433
 434 int
 435 spatial_to_pattern3(struct spatial *s)
 436 {
 437         assert(s->dist == 3);
 438         int pat3 = 0;
 439         for (int i = 1; i < 9; i++)
 440                 pat3 |= spatial_point_at(*s, i) << (p3bits[i] * 2);
 441         return pat3;
 442 }
 443
 444 int
 445 pattern3_by_spatial(struct spatial_dict *dict, int pat3)
 446 {
 447         /* Just pull pat3 through the spatial database to generate
 448          * hash of its canonical form. */
 449         int s;
 450         for (int r = 0; r < PTH__ROTATIONS; r++) {
 451                 hash_t h = pattern3_to_spatial(r, pat3);
 452                 s = spatial_dict_get(dict, 3, h);
 453                 if (s > 0) break;
 454                 /* We might need to try another rotation in case
 455                  * of a collision. */
 456         }
 457         /* XXX: We assume our spatial dictionary is _sane_, that is,
 458          * all valid 3x3 patterns we could encounter are in the
 459          * dictionary. If you hit this assert(), you probably
 460          * generated the spatial dict over too few games; it is best
 461          * to generate it over the same set of games as you match
 462          * patterns on afterwards. */
 463         assert(s > 0);
 464         return spatial_to_pattern3(&dict->spatials[s]);
 465 }