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
  13 /* Mapping from point sequence to coordinate offsets (to determine
  14  * coordinates relative to pattern center). The array is ordered
  15  * in the gridcular metric order so that we can go through it
  16  * and incrementally match spatial features in nested circles.
  17  * Within one circle, coordinates are ordered by rows to keep
  18  * good cache behavior. */
  19 struct ptcoord ptcoords[MAX_PATTERN_AREA];
  20
  21 /* For each radius, starting index in ptcoords[]. */
  22 int ptind[MAX_PATTERN_DIST + 2];
  23
  24 /* ptcoords[], ptind[] setup */
  25 static void
  26 ptcoords_init(void)
  27 {
  28         int i = 0; /* Indexing ptcoords[] */
  29
  30         /* First, center point. */
  31         ptind[0] = ptind[1] = 0;
  32         ptcoords[i].x = ptcoords[i].y = 0; i++;
  33
  34         for (int d = 2; d <= MAX_PATTERN_DIST; d++) {
  35                 ptind[d] = i;
  36                 /* For each y, examine all integer solutions
  37                  * of d = |x| + |y| + max(|x|, |y|). */
  38                 /* TODO: (Stern, 2006) uses a hand-modified
  39                  * circles that are finer for small d and more
  40                  * coarse for large 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 h1 = 0xd6d6d6d1;
  96         hash_t h2 = 0xd6d6d6d2;
  97         hash_t h3 = 0xd6d6d6d3;
  98         hash_t h4 = 0xd6d6d6d4;
  99         for (int i = 0; i < MAX_PATTERN_AREA; i++) {
 100                 pthboard[i][S_NONE] = (h1 = h1 * 16787);
 101                 pthboard[i][S_BLACK] = (h2 = h2 * 16823);
 102                 pthboard[i][S_WHITE] = (h3 = h3 * 16811 - 13);
 103                 pthboard[i][S_OFFBOARD] = (h4 = h4 * 16811);
 104         }
 105
 106         /* Virtual board with hashes created, now fill
 107          * pthashes[] with hashes for points in actual
 108          * sequences, also considering various rotations. */
 109 #define PTH_VMIRROR     1
 110 #define PTH_HMIRROR     2
 111 #define PTH_90ROT       4
 112         for (int r = 0; r < PTH__ROTATIONS; r++) {
 113                 for (int i = 0; i < MAX_PATTERN_AREA; i++) {
 114                         /* Rotate appropriately. */
 115                         int rx = ptcoords[i].x;
 116                         int ry = ptcoords[i].y;
 117                         if (r & PTH_VMIRROR) ry = -ry;
 118                         if (r & PTH_HMIRROR) rx = -rx;
 119                         if (r & PTH_90ROT) {
 120                                 int rs = rx; rx = -ry; ry = rs;
 121                         }
 122                         int bi = pthbc + ry * MAX_PATTERN_DIST + rx;
 123
 124                         /* Copy info. */
 125                         pthashes[r][i][S_NONE] = pthboard[bi][S_NONE];
 126                         pthashes[r][i][S_BLACK] = pthboard[bi][S_BLACK];
 127                         pthashes[r][i][S_WHITE] = pthboard[bi][S_WHITE];
 128                         pthashes[r][i][S_OFFBOARD] = pthboard[bi][S_OFFBOARD];
 129                 }
 130         }
 131 }
 132
 133 static void __attribute__((constructor))
 134 spatial_init(void)
 135 {
 136         /* Initialization of various static data structures for
 137          * fast pattern processing. */
 138         ptcoords_init();
 139         pthashes_init();
 140 }
 141
 142 inline hash_t
 143 spatial_hash(int rotation, struct spatial *s)
 144 {
 145         hash_t h = 0;
 146         for (int i = 0; i < ptind[s->dist + 1]; i++) {
 147                 h ^= pthashes[rotation][i][spatial_point_at(*s, i)];
 148         }
 149         return h & spatial_hash_mask;
 150 }
 151
 152 char *
 153 spatial2str(struct spatial *s)
 154 {
 155         static char buf[1024];
 156         for (int i = 0; i < ptind[s->dist + 1]; i++) {
 157                 buf[i] = stone2char(spatial_point_at(*s, i));
 158         }
 159         buf[ptind[s->dist + 1]] = 0;
 160         return buf;
 161 }
 162
 163 void
 164 spatial_from_board(struct pattern_config *pc, struct spatial *s,
 165                    struct board *b, struct move *m)
 166 {
 167         assert(pc->spat_min > 0);
 168
 169         /* We record all spatial patterns black-to-play; simply
 170          * reverse all colors if we are white-to-play. */
 171         static enum stone bt_black[4] = { S_NONE, S_BLACK, S_WHITE, S_OFFBOARD };
 172         static enum stone bt_white[4] = { S_NONE, S_WHITE, S_BLACK, S_OFFBOARD };
 173         enum stone (*bt)[4] = m->color == S_WHITE ? &bt_white : &bt_black;
 174
 175         memset(s, 0, sizeof(*s));
 176         for (int j = 0; j < ptind[pc->spat_max + 1]; j++) {
 177                 ptcoords_at(x, y, m->coord, b, j);
 178                 s->points[j / 4] |= (*bt)[board_atxy(b, x, y)] << ((j % 4) * 2);
 179         }
 180         s->dist = pc->spat_max;
 181 }
 182
 183 /* Compare two spatials, allowing for differences up to isomorphism.
 184  * True means the spatials are equivalent. */
 185 static bool
 186 spatial_cmp(struct spatial *s1, struct spatial *s2)
 187 {
 188         /* Quick preliminary check. */
 189         if (s1->dist != s2->dist)
 190                 return false;
 191
 192         /* We could create complex transposition tables, but it seems most
 193          * foolproof to just check if the sets of rotation hashes are the
 194          * same for both. */
 195         hash_t s1r[PTH__ROTATIONS];
 196         for (int r = 0; r < PTH__ROTATIONS; r++)
 197                 s1r[r] = spatial_hash(r, s1);
 198         for (int r = 0; r < PTH__ROTATIONS; r++) {
 199                 hash_t s2r = spatial_hash(r, s2);
 200                 for (int p = 0; p < PTH__ROTATIONS; p++)
 201                         if (s2r == s1r[p])
 202                                 goto found_rot;
 203                 /* Rotation hash s2r does not correspond to s1r. */
 204                 return false;
 205 found_rot:;
 206         }
 207
 208         /* All rotation hashes of s2 occur in s1. Hopefully that
 209          * indicates something. */
 210         return true;
 211 }
 212
 213
 214 /* Spatial dict manipulation. */
 215
 216 static unsigned int
 217 spatial_dict_addc(struct spatial_dict *dict, struct spatial *s)
 218 {
 219         /* Allocate space in 1024 blocks. */
 220 #define SPATIALS_ALLOC 1024
 221         if (!(dict->nspatials % SPATIALS_ALLOC)) {
 222                 dict->spatials = realloc(dict->spatials,
 223                                 (dict->nspatials + SPATIALS_ALLOC)
 224                                 * sizeof(*dict->spatials));
 225         }
 226         dict->spatials[dict->nspatials] = *s;
 227         return dict->nspatials++;
 228 }
 229
 230 static bool
 231 spatial_dict_addh(struct spatial_dict *dict, hash_t hash, unsigned int id)
 232 {
 233         if (dict->hash[hash] && dict->hash[hash] != id)
 234                 dict->collisions++;
 235         dict->hash[hash] = id;
 236         return true;
 237 }
 238
 239 /* Spatial dictionary file format:
 240  * /^#/ - comments
 241  * INDEX RADIUS STONES HASH...
 242  * INDEX: index in the spatial table
 243  * RADIUS: @d of the pattern
 244  * STONES: string of ".XO#" chars
 245  * HASH...: space-separated 18bit hash-table indices for the pattern */
 246
 247 static void
 248 spatial_dict_read(struct spatial_dict *dict, char *buf)
 249 {
 250         /* XXX: We trust the data. Bad data will crash us. */
 251         char *bufp = buf;
 252
 253         int index, radius;
 254         index = strtol(bufp, &bufp, 10);
 255         radius = strtol(bufp, &bufp, 10);
 256         while (isspace(*bufp)) bufp++;
 257
 258         /* Load the stone configuration. */
 259         struct spatial s = { .dist = radius };
 260         int sl = 0;
 261         while (!isspace(*bufp)) {
 262                 s.points[sl / 4] |= char2stone(*bufp++) << ((sl % 4)*2);
 263                 sl++;
 264         }
 265         while (isspace(*bufp)) bufp++;
 266
 267         /* Sanity check. */
 268         if (sl != ptind[s.dist + 1]) {
 269                 fprintf(stderr, "Spatial dictionary: Invalid number of stones (%d != %d) on this line: %s\n",
 270                         sl, ptind[radius + 1] - 1, buf);
 271                 exit(EXIT_FAILURE);
 272         }
 273
 274         /* Add to collection. */
 275         unsigned int id = spatial_dict_addc(dict, &s);
 276
 277         /* Add to specified hash places. */
 278         for (int r = 0; r < PTH__ROTATIONS; r++)
 279                 spatial_dict_addh(dict, spatial_hash(r, &s), id);
 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         if (DEBUGL(1))
 314                 fprintf(stderr, "Loaded spatial dictionary of %d patterns (hash: %d coll., %d effective, %.2f%% fill rate).\n",
 315                         dict->nspatials, dict->collisions, dict->collisions / PTH__ROTATIONS,
 316                         (double) dict->nspatials * 100 / (sizeof(dict->hash) / sizeof(dict->hash[0])));
 317 }
 318
 319 void
 320 spatial_dict_writeinfo(struct spatial_dict *dict, FILE *f)
 321 {
 322         /* New file. First, create a comment describing order
 323          * of points in the array. This is just for purposes
 324          * of external tools, Pachi never interprets it itself. */
 325         fprintf(f, "# Pachi spatial patterns dictionary v1.0 maxdist %d\n",
 326                 MAX_PATTERN_DIST);
 327         for (int d = 0; d <= MAX_PATTERN_DIST; d++) {
 328                 fprintf(f, "# Point order: d=%d ", d);
 329                 for (int j = ptind[d]; j < ptind[d + 1]; j++) {
 330                         fprintf(f, "%d,%d ", ptcoords[j].x, ptcoords[j].y);
 331                 }
 332                 fprintf(f, "\n");
 333         }
 334 }
 335
 336 const char *spatial_dict_filename = "patterns.spat";
 337 struct spatial_dict *
 338 spatial_dict_init(bool will_append)
 339 {
 340         FILE *f = fopen(spatial_dict_filename, "r");
 341         if (!f && !will_append) {
 342                 if (DEBUGL(1))
 343                         fprintf(stderr, "No spatial dictionary, will not match spatial pattern features.\n");
 344                 return NULL;
 345         }
 346
 347         struct spatial_dict *dict = calloc2(1, sizeof(*dict));
 348         /* We create a dummy record for index 0 that we will
 349          * never reference. This is so that hash value 0 can
 350          * represent "no value". */
 351         struct spatial dummy = { .dist = 0 };
 352         spatial_dict_addc(dict, &dummy);
 353
 354         if (f) {
 355                 spatial_dict_load(dict, f);
 356                 fclose(f); f = NULL;
 357         } else {
 358                 assert(will_append);
 359         }
 360
 361         return dict;
 362 }
 363
 364 int
 365 spatial_dict_put(struct spatial_dict *dict, struct spatial *s, hash_t h)
 366 {
 367         /* We avoid spatial_dict_get() here, since we want to ignore radius
 368          * differences - we have custom collision detection. */
 369         int id = dict->hash[h];
 370         if (id > 0) {
 371                 /* Is this the same or isomorphous spatial? */
 372                 if (spatial_cmp(s, &dict->spatials[id]))
 373                         return id;
 374
 375                 /* Look a bit harder - perhaps one of our rotations still
 376                  * points at the correct spatial. */
 377                 for (int r = 0; r < PTH__ROTATIONS; r++) {
 378                         hash_t rhash = spatial_hash(r, s);
 379                         int rid = dict->hash[rhash];
 380                         /* No match means we definitely aren't stored yet. */
 381                         if (!rid)
 382                                 break;
 383                         if (id != rid && spatial_cmp(s, &dict->spatials[rid])) {
 384                                 /* Yay, this is us! */
 385                                 if (DEBUGL(3))
 386                                         fprintf(stderr, "Repeated collision %d vs %d\n", id, rid);
 387                                 id = rid;
 388                                 /* Point the hashes back to us. */
 389                                 goto hash_store;
 390                         }
 391                 }
 392
 393                 if (DEBUGL(1))
 394                         fprintf(stderr, "Collision %d vs %d\n", id, dict->nspatials);
 395                 id = 0;
 396                 /* dict->collisions++; gets done by addh */
 397         }
 398
 399         /* Add new pattern! */
 400         id = spatial_dict_addc(dict, s);
 401         if (DEBUGL(4)) {
 402                 fprintf(stderr, "new spat %d(%d) %s <%"PRIhash"> ", id, s->dist, spatial2str(s), h);
 403                 for (int r = 0; r < 8; r++)
 404                         fprintf(stderr,"[%"PRIhash"] ", spatial_hash(r, s));
 405                 fprintf(stderr, "\n");
 406         }
 407
 408         /* Store new pattern in the hash. */
 409 hash_store:
 410         for (int r = 0; r < PTH__ROTATIONS; r++)
 411                 spatial_dict_addh(dict, spatial_hash(r, s), id);
 412
 413         return id;
 414 }