pattern.c

   1 /*
   2  * pattern.c: the pattern-reconstruction game known as `nonograms'.
   3  */
   4
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <string.h>
   8 #include <assert.h>
   9 #include <ctype.h>
  10 #include <math.h>
  11
  12 #include "puzzles.h"
  13
  14 enum {
  15     COL_BACKGROUND,
  16     COL_EMPTY,
  17     COL_FULL,
  18     COL_TEXT,
  19     COL_UNKNOWN,
  20     COL_GRID,
  21     NCOLOURS
  22 };
  23
  24 #define PREFERRED_TILE_SIZE 24
  25 #define TILE_SIZE (ds->tilesize)
  26 #define BORDER (3 * TILE_SIZE / 4)
  27 #define TLBORDER(d) ( (d) / 5 + 2 )
  28 #define GUTTER (TILE_SIZE / 2)
  29
  30 #define FROMCOORD(d, x) \
  31         ( ((x) - (BORDER + GUTTER + TILE_SIZE * TLBORDER(d))) / TILE_SIZE )
  32
  33 #define SIZE(d) (2*BORDER + GUTTER + TILE_SIZE * (TLBORDER(d) + (d)))
  34 #define GETTILESIZE(d, w) ((double)w / (2.0 + (double)TLBORDER(d) + (double)(d)))
  35
  36 #define TOCOORD(d, x) (BORDER + GUTTER + TILE_SIZE * (TLBORDER(d) + (x)))
  37
  38 struct game_params {
  39     int w, h;
  40 };
  41
  42 #define GRID_UNKNOWN 2
  43 #define GRID_FULL 1
  44 #define GRID_EMPTY 0
  45
  46 struct game_state {
  47     int w, h;
  48     unsigned char *grid;
  49     int rowsize;
  50     int *rowdata, *rowlen;
  51     int completed, cheated;
  52 };
  53
  54 #define FLASH_TIME 0.13F
  55
  56 static game_params *default_params(void)
  57 {
  58     game_params *ret = snew(game_params);
  59
  60     ret->w = ret->h = 15;
  61
  62     return ret;
  63 }
  64
  65 static const struct game_params pattern_presets[] = {
  66     {10, 10},
  67     {15, 15},
  68     {20, 20},
  69 #ifndef SLOW_SYSTEM
  70     {25, 25},
  71     {30, 30},
  72 #endif
  73 };
  74
  75 static int game_fetch_preset(int i, char **name, game_params **params)
  76 {
  77     game_params *ret;
  78     char str[80];
  79
  80     if (i < 0 || i >= lenof(pattern_presets))
  81         return FALSE;
  82
  83     ret = snew(game_params);
  84     *ret = pattern_presets[i];
  85
  86     sprintf(str, "%dx%d", ret->w, ret->h);
  87
  88     *name = dupstr(str);
  89     *params = ret;
  90     return TRUE;
  91 }
  92
  93 static void free_params(game_params *params)
  94 {
  95     sfree(params);
  96 }
  97
  98 static game_params *dup_params(game_params *params)
  99 {
 100     game_params *ret = snew(game_params);
 101     *ret = *params;                    /* structure copy */
 102     return ret;
 103 }
 104
 105 static void decode_params(game_params *ret, char const *string)
 106 {
 107     char const *p = string;
 108
 109     ret->w = atoi(p);
 110     while (*p && isdigit((unsigned char)*p)) p++;
 111     if (*p == 'x') {
 112         p++;
 113         ret->h = atoi(p);
 114         while (*p && isdigit((unsigned char)*p)) p++;
 115     } else {
 116         ret->h = ret->w;
 117     }
 118 }
 119
 120 static char *encode_params(game_params *params, int full)
 121 {
 122     char ret[400];
 123     int len;
 124
 125     len = sprintf(ret, "%dx%d", params->w, params->h);
 126     assert(len < lenof(ret));
 127     ret[len] = '\0';
 128
 129     return dupstr(ret);
 130 }
 131
 132 static config_item *game_configure(game_params *params)
 133 {
 134     config_item *ret;
 135     char buf[80];
 136
 137     ret = snewn(3, config_item);
 138
 139     ret[0].name = "Width";
 140     ret[0].type = C_STRING;
 141     sprintf(buf, "%d", params->w);
 142     ret[0].sval = dupstr(buf);
 143     ret[0].ival = 0;
 144
 145     ret[1].name = "Height";
 146     ret[1].type = C_STRING;
 147     sprintf(buf, "%d", params->h);
 148     ret[1].sval = dupstr(buf);
 149     ret[1].ival = 0;
 150
 151     ret[2].name = NULL;
 152     ret[2].type = C_END;
 153     ret[2].sval = NULL;
 154     ret[2].ival = 0;
 155
 156     return ret;
 157 }
 158
 159 static game_params *custom_params(config_item *cfg)
 160 {
 161     game_params *ret = snew(game_params);
 162
 163     ret->w = atoi(cfg[0].sval);
 164     ret->h = atoi(cfg[1].sval);
 165
 166     return ret;
 167 }
 168
 169 static char *validate_params(game_params *params, int full)
 170 {
 171     if (params->w <= 0 || params->h <= 0)
 172         return "Width and height must both be greater than zero";
 173     return NULL;
 174 }
 175
 176 /* ----------------------------------------------------------------------
 177  * Puzzle generation code.
 178  *
 179  * For this particular puzzle, it seemed important to me to ensure
 180  * a unique solution. I do this the brute-force way, by having a
 181  * solver algorithm alongside the generator, and repeatedly
 182  * generating a random grid until I find one whose solution is
 183  * unique. It turns out that this isn't too onerous on a modern PC
 184  * provided you keep grid size below around 30. Any offers of
 185  * better algorithms, however, will be very gratefully received.
 186  *
 187  * Another annoyance of this approach is that it limits the
 188  * available puzzles to those solvable by the algorithm I've used.
 189  * My algorithm only ever considers a single row or column at any
 190  * one time, which means it's incapable of solving the following
 191  * difficult example (found by Bella Image around 1995/6, when she
 192  * and I were both doing maths degrees):
 193  *
 194  *        2  1  2  1
 195  *
 196  *      +--+--+--+--+
 197  * 1 1  |  |  |  |  |
 198  *      +--+--+--+--+
 199  *   2  |  |  |  |  |
 200  *      +--+--+--+--+
 201  *   1  |  |  |  |  |
 202  *      +--+--+--+--+
 203  *   1  |  |  |  |  |
 204  *      +--+--+--+--+
 205  *
 206  * Obviously this cannot be solved by a one-row-or-column-at-a-time
 207  * algorithm (it would require at least one row or column reading
 208  * `2 1', `1 2', `3' or `4' to get started). However, it can be
 209  * proved to have a unique solution: if the top left square were
 210  * empty, then the only option for the top row would be to fill the
 211  * two squares in the 1 columns, which would imply the squares
 212  * below those were empty, leaving no place for the 2 in the second
 213  * row. Contradiction. Hence the top left square is full, and the
 214  * unique solution follows easily from that starting point.
 215  *
 216  * (The game ID for this puzzle is 4x4:2/1/2/1/1.1/2/1/1 , in case
 217  * it's useful to anyone.)
 218  */
 219
 220 static int float_compare(const void *av, const void *bv)
 221 {
 222     const float *a = (const float *)av;
 223     const float *b = (const float *)bv;
 224     if (*a < *b)
 225         return -1;
 226     else if (*a > *b)
 227         return +1;
 228     else
 229         return 0;
 230 }
 231
 232 static void generate(random_state *rs, int w, int h, unsigned char *retgrid)
 233 {
 234     float *fgrid;
 235     float *fgrid2;
 236     int step, i, j;
 237     float threshold;
 238
 239     fgrid = snewn(w*h, float);
 240
 241     for (i = 0; i < h; i++) {
 242         for (j = 0; j < w; j++) {
 243             fgrid[i*w+j] = random_upto(rs, 100000000UL) / 100000000.F;
 244         }
 245     }
 246
 247     /*
 248      * The above gives a completely random splattering of black and
 249      * white cells. We want to gently bias this in favour of _some_
 250      * reasonably thick areas of white and black, while retaining
 251      * some randomness and fine detail.
 252      *
 253      * So we evolve the starting grid using a cellular automaton.
 254      * Currently, I'm doing something very simple indeed, which is
 255      * to set each square to the average of the surrounding nine
 256      * cells (or the average of fewer, if we're on a corner).
 257      */
 258     for (step = 0; step < 1; step++) {
 259         fgrid2 = snewn(w*h, float);
 260
 261         for (i = 0; i < h; i++) {
 262             for (j = 0; j < w; j++) {
 263                 float sx, xbar;
 264                 int n, p, q;
 265
 266                 /*
 267                  * Compute the average of the surrounding cells.
 268                  */
 269                 n = 0;
 270                 sx = 0.F;
 271                 for (p = -1; p <= +1; p++) {
 272                     for (q = -1; q <= +1; q++) {
 273                         if (i+p < 0 || i+p >= h || j+q < 0 || j+q >= w)
 274                             continue;
 275                         /*
 276                          * An additional special case not mentioned
 277                          * above: if a grid dimension is 2xn then
 278                          * we do not average across that dimension
 279                          * at all. Otherwise a 2x2 grid would
 280                          * contain four identical squares.
 281                          */
 282                         if ((h==2 && p!=0) || (w==2 && q!=0))
 283                             continue;
 284                         n++;
 285                         sx += fgrid[(i+p)*w+(j+q)];
 286                     }
 287                 }
 288                 xbar = sx / n;
 289
 290                 fgrid2[i*w+j] = xbar;
 291             }
 292         }
 293
 294         sfree(fgrid);
 295         fgrid = fgrid2;
 296     }
 297
 298     fgrid2 = snewn(w*h, float);
 299     memcpy(fgrid2, fgrid, w*h*sizeof(float));
 300     qsort(fgrid2, w*h, sizeof(float), float_compare);
 301     threshold = fgrid2[w*h/2];
 302     sfree(fgrid2);
 303
 304     for (i = 0; i < h; i++) {
 305         for (j = 0; j < w; j++) {
 306             retgrid[i*w+j] = (fgrid[i*w+j] >= threshold ? GRID_FULL :
 307                               GRID_EMPTY);
 308         }
 309     }
 310
 311     sfree(fgrid);
 312 }
 313
 314 static int compute_rowdata(int *ret, unsigned char *start, int len, int step)
 315 {
 316     int i, n;
 317
 318     n = 0;
 319
 320     for (i = 0; i < len; i++) {
 321         if (start[i*step] == GRID_FULL) {
 322             int runlen = 1;
 323             while (i+runlen < len && start[(i+runlen)*step] == GRID_FULL)
 324                 runlen++;
 325             ret[n++] = runlen;
 326             i += runlen;
 327         }
 328
 329         if (i < len && start[i*step] == GRID_UNKNOWN)
 330             return -1;
 331     }
 332
 333     return n;
 334 }
 335
 336 #define UNKNOWN 0
 337 #define BLOCK 1
 338 #define DOT 2
 339 #define STILL_UNKNOWN 3
 340
 341 static void do_recurse(unsigned char *known, unsigned char *deduced,
 342                        unsigned char *row, int *data, int len,
 343                        int freespace, int ndone, int lowest)
 344 {
 345     int i, j, k;
 346
 347     if (data[ndone]) {
 348         for (i=0; i<=freespace; i++) {
 349             j = lowest;
 350             for (k=0; k<i; k++) row[j++] = DOT;
 351             for (k=0; k<data[ndone]; k++) row[j++] = BLOCK;
 352             if (j < len) row[j++] = DOT;
 353             do_recurse(known, deduced, row, data, len,
 354                        freespace-i, ndone+1, j);
 355         }
 356     } else {
 357         for (i=lowest; i<len; i++)
 358             row[i] = DOT;
 359         for (i=0; i<len; i++)
 360             if (known[i] && known[i] != row[i])
 361                 return;
 362         for (i=0; i<len; i++)
 363             deduced[i] |= row[i];
 364     }
 365 }
 366
 367 static int do_row(unsigned char *known, unsigned char *deduced,
 368                   unsigned char *row,
 369                   unsigned char *start, int len, int step, int *data)
 370 {
 371     int rowlen, i, freespace, done_any;
 372
 373     freespace = len+1;
 374     for (rowlen = 0; data[rowlen]; rowlen++)
 375         freespace -= data[rowlen]+1;
 376
 377     for (i = 0; i < len; i++) {
 378         known[i] = start[i*step];
 379         deduced[i] = 0;
 380     }
 381
 382     do_recurse(known, deduced, row, data, len, freespace, 0, 0);
 383     done_any = FALSE;
 384     for (i=0; i<len; i++)
 385         if (deduced[i] && deduced[i] != STILL_UNKNOWN && !known[i]) {
 386             start[i*step] = deduced[i];
 387             done_any = TRUE;
 388         }
 389     return done_any;
 390 }
 391
 392 static unsigned char *generate_soluble(random_state *rs, int w, int h)
 393 {
 394     int i, j, done_any, ok, ntries, max;
 395     unsigned char *grid, *matrix, *workspace;
 396     int *rowdata;
 397
 398     grid = snewn(w*h, unsigned char);
 399     matrix = snewn(w*h, unsigned char);
 400     max = max(w, h);
 401     workspace = snewn(max*3, unsigned char);
 402     rowdata = snewn(max+1, int);
 403
 404     ntries = 0;
 405
 406     do {
 407         ntries++;
 408
 409         generate(rs, w, h, grid);
 410
 411         /*
 412          * The game is a bit too easy if any row or column is
 413          * completely black or completely white. An exception is
 414          * made for rows/columns that are under 3 squares,
 415          * otherwise nothing will ever be successfully generated.
 416          */
 417         ok = TRUE;
 418         if (w > 2) {
 419             for (i = 0; i < h; i++) {
 420                 int colours = 0;
 421                 for (j = 0; j < w; j++)
 422                     colours |= (grid[i*w+j] == GRID_FULL ? 2 : 1);
 423                 if (colours != 3)
 424                     ok = FALSE;
 425             }
 426         }
 427         if (h > 2) {
 428             for (j = 0; j < w; j++) {
 429                 int colours = 0;
 430                 for (i = 0; i < h; i++)
 431                     colours |= (grid[i*w+j] == GRID_FULL ? 2 : 1);
 432                 if (colours != 3)
 433                     ok = FALSE;
 434             }
 435         }
 436         if (!ok)
 437             continue;
 438
 439         memset(matrix, 0, w*h);
 440
 441         do {
 442             done_any = 0;
 443             for (i=0; i<h; i++) {
 444                 rowdata[compute_rowdata(rowdata, grid+i*w, w, 1)] = 0;
 445                 done_any |= do_row(workspace, workspace+max, workspace+2*max,
 446                                    matrix+i*w, w, 1, rowdata);
 447             }
 448             for (i=0; i<w; i++) {
 449                 rowdata[compute_rowdata(rowdata, grid+i, h, w)] = 0;
 450                 done_any |= do_row(workspace, workspace+max, workspace+2*max,
 451                                    matrix+i, h, w, rowdata);
 452             }
 453         } while (done_any);
 454
 455         ok = TRUE;
 456         for (i=0; i<h; i++) {
 457             for (j=0; j<w; j++) {
 458                 if (matrix[i*w+j] == UNKNOWN)
 459                     ok = FALSE;
 460             }
 461         }
 462     } while (!ok);
 463
 464     sfree(matrix);
 465     sfree(workspace);
 466     sfree(rowdata);
 467     return grid;
 468 }
 469
 470 static char *new_game_desc(game_params *params, random_state *rs,
 471                            char **aux, int interactive)
 472 {
 473     unsigned char *grid;
 474     int i, j, max, rowlen, *rowdata;
 475     char intbuf[80], *desc;
 476     int desclen, descpos;
 477
 478     grid = generate_soluble(rs, params->w, params->h);
 479     max = max(params->w, params->h);
 480     rowdata = snewn(max, int);
 481
 482     /*
 483      * Save the solved game in aux.
 484      */
 485     {
 486         char *ai = snewn(params->w * params->h + 2, char);
 487
 488         /*
 489          * String format is exactly the same as a solve move, so we
 490          * can just dupstr this in solve_game().
 491          */
 492
 493         ai[0] = 'S';
 494
 495         for (i = 0; i < params->w * params->h; i++)
 496             ai[i+1] = grid[i] ? '1' : '0';
 497
 498         ai[params->w * params->h + 1] = '\0';
 499
 500         *aux = ai;
 501     }
 502
 503     /*
 504      * Seed is a slash-separated list of row contents; each row
 505      * contents section is a dot-separated list of integers. Row
 506      * contents are listed in the order (columns left to right,
 507      * then rows top to bottom).
 508      *
 509      * Simplest way to handle memory allocation is to make two
 510      * passes, first computing the seed size and then writing it
 511      * out.
 512      */
 513     desclen = 0;
 514     for (i = 0; i < params->w + params->h; i++) {
 515         if (i < params->w)
 516             rowlen = compute_rowdata(rowdata, grid+i, params->h, params->w);
 517         else
 518             rowlen = compute_rowdata(rowdata, grid+(i-params->w)*params->w,
 519                                      params->w, 1);
 520         if (rowlen > 0) {
 521             for (j = 0; j < rowlen; j++) {
 522                 desclen += 1 + sprintf(intbuf, "%d", rowdata[j]);
 523             }
 524         } else {
 525             desclen++;
 526         }
 527     }
 528     desc = snewn(desclen, char);
 529     descpos = 0;
 530     for (i = 0; i < params->w + params->h; i++) {
 531         if (i < params->w)
 532             rowlen = compute_rowdata(rowdata, grid+i, params->h, params->w);
 533         else
 534             rowlen = compute_rowdata(rowdata, grid+(i-params->w)*params->w,
 535                                      params->w, 1);
 536         if (rowlen > 0) {
 537             for (j = 0; j < rowlen; j++) {
 538                 int len = sprintf(desc+descpos, "%d", rowdata[j]);
 539                 if (j+1 < rowlen)
 540                     desc[descpos + len] = '.';
 541                 else
 542                     desc[descpos + len] = '/';
 543                 descpos += len+1;
 544             }
 545         } else {
 546             desc[descpos++] = '/';
 547         }
 548     }
 549     assert(descpos == desclen);
 550     assert(desc[desclen-1] == '/');
 551     desc[desclen-1] = '\0';
 552     sfree(rowdata);
 553     sfree(grid);
 554     return desc;
 555 }
 556
 557 static char *validate_desc(game_params *params, char *desc)
 558 {
 559     int i, n, rowspace;
 560     char *p;
 561
 562     for (i = 0; i < params->w + params->h; i++) {
 563         if (i < params->w)
 564             rowspace = params->h + 1;
 565         else
 566             rowspace = params->w + 1;
 567
 568         if (*desc && isdigit((unsigned char)*desc)) {
 569             do {
 570                 p = desc;
 571                 while (desc && isdigit((unsigned char)*desc)) desc++;
 572                 n = atoi(p);
 573                 rowspace -= n+1;
 574
 575                 if (rowspace < 0) {
 576                     if (i < params->w)
 577                         return "at least one column contains more numbers than will fit";
 578                     else
 579                         return "at least one row contains more numbers than will fit";
 580                 }
 581             } while (*desc++ == '.');
 582         } else {
 583             desc++;                    /* expect a slash immediately */
 584         }
 585
 586         if (desc[-1] == '/') {
 587             if (i+1 == params->w + params->h)
 588                 return "too many row/column specifications";
 589         } else if (desc[-1] == '\0') {
 590             if (i+1 < params->w + params->h)
 591                 return "too few row/column specifications";
 592         } else
 593             return "unrecognised character in game specification";
 594     }
 595
 596     return NULL;
 597 }
 598
 599 static game_state *new_game(midend *me, game_params *params, char *desc)
 600 {
 601     int i;
 602     char *p;
 603     game_state *state = snew(game_state);
 604
 605     state->w = params->w;
 606     state->h = params->h;
 607
 608     state->grid = snewn(state->w * state->h, unsigned char);
 609     memset(state->grid, GRID_UNKNOWN, state->w * state->h);
 610
 611     state->rowsize = max(state->w, state->h);
 612     state->rowdata = snewn(state->rowsize * (state->w + state->h), int);
 613     state->rowlen = snewn(state->w + state->h, int);
 614
 615     state->completed = state->cheated = FALSE;
 616
 617     for (i = 0; i < params->w + params->h; i++) {
 618         state->rowlen[i] = 0;
 619         if (*desc && isdigit((unsigned char)*desc)) {
 620             do {
 621                 p = desc;
 622                 while (desc && isdigit((unsigned char)*desc)) desc++;
 623                 state->rowdata[state->rowsize * i + state->rowlen[i]++] =
 624                     atoi(p);
 625             } while (*desc++ == '.');
 626         } else {
 627             desc++;                    /* expect a slash immediately */
 628         }
 629     }
 630
 631     return state;
 632 }
 633
 634 static game_state *dup_game(game_state *state)
 635 {
 636     game_state *ret = snew(game_state);
 637
 638     ret->w = state->w;
 639     ret->h = state->h;
 640
 641     ret->grid = snewn(ret->w * ret->h, unsigned char);
 642     memcpy(ret->grid, state->grid, ret->w * ret->h);
 643
 644     ret->rowsize = state->rowsize;
 645     ret->rowdata = snewn(ret->rowsize * (ret->w + ret->h), int);
 646     ret->rowlen = snewn(ret->w + ret->h, int);
 647     memcpy(ret->rowdata, state->rowdata,
 648            ret->rowsize * (ret->w + ret->h) * sizeof(int));
 649     memcpy(ret->rowlen, state->rowlen,
 650            (ret->w + ret->h) * sizeof(int));
 651
 652     ret->completed = state->completed;
 653     ret->cheated = state->cheated;
 654
 655     return ret;
 656 }
 657
 658 static void free_game(game_state *state)
 659 {
 660     sfree(state->rowdata);
 661     sfree(state->rowlen);
 662     sfree(state->grid);
 663     sfree(state);
 664 }
 665
 666 static char *solve_game(game_state *state, game_state *currstate,
 667                         char *ai, char **error)
 668 {
 669     unsigned char *matrix;
 670     int w = state->w, h = state->h;
 671     int i;
 672     char *ret;
 673     int done_any, max;
 674     unsigned char *workspace;
 675     int *rowdata;
 676
 677     /*
 678      * If we already have the solved state in ai, copy it out.
 679      */
 680     if (ai)
 681         return dupstr(ai);
 682
 683     matrix = snewn(w*h, unsigned char);
 684     max = max(w, h);
 685     workspace = snewn(max*3, unsigned char);
 686     rowdata = snewn(max+1, int);
 687
 688     memset(matrix, 0, w*h);
 689
 690     do {
 691         done_any = 0;
 692         for (i=0; i<h; i++) {
 693             memcpy(rowdata, state->rowdata + state->rowsize*(w+i),
 694                    max*sizeof(int));
 695             rowdata[state->rowlen[w+i]] = 0;
 696             done_any |= do_row(workspace, workspace+max, workspace+2*max,
 697                                matrix+i*w, w, 1, rowdata);
 698         }
 699         for (i=0; i<w; i++) {
 700             memcpy(rowdata, state->rowdata + state->rowsize*i, max*sizeof(int));
 701             rowdata[state->rowlen[i]] = 0;
 702             done_any |= do_row(workspace, workspace+max, workspace+2*max,
 703                                matrix+i, h, w, rowdata);
 704         }
 705     } while (done_any);
 706
 707     sfree(workspace);
 708     sfree(rowdata);
 709
 710     for (i = 0; i < w*h; i++) {
 711         if (matrix[i] != BLOCK && matrix[i] != DOT) {
 712             sfree(matrix);
 713             *error = "Solving algorithm cannot complete this puzzle";
 714             return NULL;
 715         }
 716     }
 717
 718     ret = snewn(w*h+2, char);
 719     ret[0] = 'S';
 720     for (i = 0; i < w*h; i++) {
 721         assert(matrix[i] == BLOCK || matrix[i] == DOT);
 722         ret[i+1] = (matrix[i] == BLOCK ? '1' : '0');
 723     }
 724     ret[w*h+1] = '\0';
 725
 726     sfree(matrix);
 727
 728     return ret;
 729 }
 730
 731 static int game_can_format_as_text_now(game_params *params)
 732 {
 733     return TRUE;
 734 }
 735
 736 static char *game_text_format(game_state *state)
 737 {
 738     return NULL;
 739 }
 740
 741 struct game_ui {
 742     int dragging;
 743     int drag_start_x;
 744     int drag_start_y;
 745     int drag_end_x;
 746     int drag_end_y;
 747     int drag, release, state;
 748 };
 749
 750 static game_ui *new_ui(game_state *state)
 751 {
 752     game_ui *ret;
 753
 754     ret = snew(game_ui);
 755     ret->dragging = FALSE;
 756
 757     return ret;
 758 }
 759
 760 static void free_ui(game_ui *ui)
 761 {
 762     sfree(ui);
 763 }
 764
 765 static char *encode_ui(game_ui *ui)
 766 {
 767     return NULL;
 768 }
 769
 770 static void decode_ui(game_ui *ui, char *encoding)
 771 {
 772 }
 773
 774 static void game_changed_state(game_ui *ui, game_state *oldstate,
 775                                game_state *newstate)
 776 {
 777 }
 778
 779 struct game_drawstate {
 780     int started;
 781     int w, h;
 782     int tilesize;
 783     unsigned char *visible;
 784 };
 785
 786 static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds,
 787                             int x, int y, int button)
 788 {
 789     button &= ~MOD_MASK;
 790
 791     x = FROMCOORD(state->w, x);
 792     y = FROMCOORD(state->h, y);
 793
 794     if (x >= 0 && x < state->w && y >= 0 && y < state->h &&
 795         (button == LEFT_BUTTON || button == RIGHT_BUTTON ||
 796          button == MIDDLE_BUTTON)) {
 797 #ifdef STYLUS_BASED
 798         int currstate = state->grid[y * state->w + x];
 799 #endif
 800
 801         ui->dragging = TRUE;
 802
 803         if (button == LEFT_BUTTON) {
 804             ui->drag = LEFT_DRAG;
 805             ui->release = LEFT_RELEASE;
 806 #ifdef STYLUS_BASED
 807             ui->state = currstate == GRID_FULL ? GRID_UNKNOWN : GRID_FULL;
 808 #else
 809             ui->state = GRID_FULL;
 810 #endif
 811         } else if (button == RIGHT_BUTTON) {
 812             ui->drag = RIGHT_DRAG;
 813             ui->release = RIGHT_RELEASE;
 814 #ifdef STYLUS_BASED
 815             ui->state = currstate == GRID_EMPTY ? GRID_UNKNOWN : GRID_EMPTY;
 816 #else
 817             ui->state = GRID_EMPTY;
 818 #endif
 819         } else /* if (button == MIDDLE_BUTTON) */ {
 820             ui->drag = MIDDLE_DRAG;
 821             ui->release = MIDDLE_RELEASE;
 822             ui->state = GRID_UNKNOWN;
 823         }
 824
 825         ui->drag_start_x = ui->drag_end_x = x;
 826         ui->drag_start_y = ui->drag_end_y = y;
 827
 828         return "";                     /* UI activity occurred */
 829     }
 830
 831     if (ui->dragging && button == ui->drag) {
 832         /*
 833          * There doesn't seem much point in allowing a rectangle
 834          * drag; people will generally only want to drag a single
 835          * horizontal or vertical line, so we make that easy by
 836          * snapping to it.
 837          *
 838          * Exception: if we're _middle_-button dragging to tag
 839          * things as UNKNOWN, we may well want to trash an entire
 840          * area and start over!
 841          */
 842         if (ui->state != GRID_UNKNOWN) {
 843             if (abs(x - ui->drag_start_x) > abs(y - ui->drag_start_y))
 844                 y = ui->drag_start_y;
 845             else
 846                 x = ui->drag_start_x;
 847         }
 848
 849         if (x < 0) x = 0;
 850         if (y < 0) y = 0;
 851         if (x >= state->w) x = state->w - 1;
 852         if (y >= state->h) y = state->h - 1;
 853
 854         ui->drag_end_x = x;
 855         ui->drag_end_y = y;
 856
 857         return "";                     /* UI activity occurred */
 858     }
 859
 860     if (ui->dragging && button == ui->release) {
 861         int x1, x2, y1, y2, xx, yy;
 862         int move_needed = FALSE;
 863
 864         x1 = min(ui->drag_start_x, ui->drag_end_x);
 865         x2 = max(ui->drag_start_x, ui->drag_end_x);
 866         y1 = min(ui->drag_start_y, ui->drag_end_y);
 867         y2 = max(ui->drag_start_y, ui->drag_end_y);
 868
 869         for (yy = y1; yy <= y2; yy++)
 870             for (xx = x1; xx <= x2; xx++)
 871                 if (state->grid[yy * state->w + xx] != ui->state)
 872                     move_needed = TRUE;
 873
 874         ui->dragging = FALSE;
 875
 876         if (move_needed) {
 877             char buf[80];
 878             sprintf(buf, "%c%d,%d,%d,%d",
 879                     (char)(ui->state == GRID_FULL ? 'F' :
 880                            ui->state == GRID_EMPTY ? 'E' : 'U'),
 881                     x1, y1, x2-x1+1, y2-y1+1);
 882             return dupstr(buf);
 883         } else
 884             return "";                 /* UI activity occurred */
 885     }
 886
 887     return NULL;
 888 }
 889
 890 static game_state *execute_move(game_state *from, char *move)
 891 {
 892     game_state *ret;
 893     int x1, x2, y1, y2, xx, yy;
 894     int val;
 895
 896     if (move[0] == 'S' && strlen(move) == from->w * from->h + 1) {
 897         int i;
 898
 899         ret = dup_game(from);
 900
 901         for (i = 0; i < ret->w * ret->h; i++)
 902             ret->grid[i] = (move[i+1] == '1' ? GRID_FULL : GRID_EMPTY);
 903
 904         ret->completed = ret->cheated = TRUE;
 905
 906         return ret;
 907     } else if ((move[0] == 'F' || move[0] == 'E' || move[0] == 'U') &&
 908         sscanf(move+1, "%d,%d,%d,%d", &x1, &y1, &x2, &y2) == 4 &&
 909         x1 >= 0 && x2 >= 0 && x1+x2 <= from->w &&
 910         y1 >= 0 && y2 >= 0 && y1+y2 <= from->h) {
 911
 912         x2 += x1;
 913         y2 += y1;
 914         val = (move[0] == 'F' ? GRID_FULL :
 915                  move[0] == 'E' ? GRID_EMPTY : GRID_UNKNOWN);
 916
 917         ret = dup_game(from);
 918         for (yy = y1; yy < y2; yy++)
 919             for (xx = x1; xx < x2; xx++)
 920                 ret->grid[yy * ret->w + xx] = val;
 921
 922         /*
 923          * An actual change, so check to see if we've completed the
 924          * game.
 925          */
 926         if (!ret->completed) {
 927             int *rowdata = snewn(ret->rowsize, int);
 928             int i, len;
 929
 930             ret->completed = TRUE;
 931
 932             for (i=0; i<ret->w; i++) {
 933                 len = compute_rowdata(rowdata,
 934                                       ret->grid+i, ret->h, ret->w);
 935                 if (len != ret->rowlen[i] ||
 936                     memcmp(ret->rowdata+i*ret->rowsize, rowdata,
 937                            len * sizeof(int))) {
 938                     ret->completed = FALSE;
 939                     break;
 940                 }
 941             }
 942             for (i=0; i<ret->h; i++) {
 943                 len = compute_rowdata(rowdata,
 944                                       ret->grid+i*ret->w, ret->w, 1);
 945                 if (len != ret->rowlen[i+ret->w] ||
 946                     memcmp(ret->rowdata+(i+ret->w)*ret->rowsize, rowdata,
 947                            len * sizeof(int))) {
 948                     ret->completed = FALSE;
 949                     break;
 950                 }
 951             }
 952
 953             sfree(rowdata);
 954         }
 955
 956         return ret;
 957     } else
 958         return NULL;
 959 }
 960
 961 /* ----------------------------------------------------------------------
 962  * Drawing routines.
 963  */
 964
 965 static void game_compute_size(game_params *params, int tilesize,
 966                               int *x, int *y)
 967 {
 968     /* Ick: fake up `ds->tilesize' for macro expansion purposes */
 969     struct { int tilesize; } ads, *ds = &ads;
 970     ads.tilesize = tilesize;
 971
 972     *x = SIZE(params->w);
 973     *y = SIZE(params->h);
 974 }
 975
 976 static void game_set_size(drawing *dr, game_drawstate *ds,
 977                           game_params *params, int tilesize)
 978 {
 979     ds->tilesize = tilesize;
 980 }
 981
 982 static float *game_colours(frontend *fe, int *ncolours)
 983 {
 984     float *ret = snewn(3 * NCOLOURS, float);
 985
 986     frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
 987
 988     ret[COL_GRID * 3 + 0] = 0.3F;
 989     ret[COL_GRID * 3 + 1] = 0.3F;
 990     ret[COL_GRID * 3 + 2] = 0.3F;
 991
 992     ret[COL_UNKNOWN * 3 + 0] = 0.5F;
 993     ret[COL_UNKNOWN * 3 + 1] = 0.5F;
 994     ret[COL_UNKNOWN * 3 + 2] = 0.5F;
 995
 996     ret[COL_TEXT * 3 + 0] = 0.0F;
 997     ret[COL_TEXT * 3 + 1] = 0.0F;
 998     ret[COL_TEXT * 3 + 2] = 0.0F;
 999
1000     ret[COL_FULL * 3 + 0] = 0.0F;
1001     ret[COL_FULL * 3 + 1] = 0.0F;
1002     ret[COL_FULL * 3 + 2] = 0.0F;
1003
1004     ret[COL_EMPTY * 3 + 0] = 1.0F;
1005     ret[COL_EMPTY * 3 + 1] = 1.0F;
1006     ret[COL_EMPTY * 3 + 2] = 1.0F;
1007
1008     *ncolours = NCOLOURS;
1009     return ret;
1010 }
1011
1012 static game_drawstate *game_new_drawstate(drawing *dr, game_state *state)
1013 {
1014     struct game_drawstate *ds = snew(struct game_drawstate);
1015
1016     ds->started = FALSE;
1017     ds->w = state->w;
1018     ds->h = state->h;
1019     ds->visible = snewn(ds->w * ds->h, unsigned char);
1020     ds->tilesize = 0;                  /* not decided yet */
1021     memset(ds->visible, 255, ds->w * ds->h);
1022
1023     return ds;
1024 }
1025
1026 static void game_free_drawstate(drawing *dr, game_drawstate *ds)
1027 {
1028     sfree(ds->visible);
1029     sfree(ds);
1030 }
1031
1032 static void grid_square(drawing *dr, game_drawstate *ds,
1033                         int y, int x, int state)
1034 {
1035     int xl, xr, yt, yb;
1036
1037     draw_rect(dr, TOCOORD(ds->w, x), TOCOORD(ds->h, y),
1038               TILE_SIZE, TILE_SIZE, COL_GRID);
1039
1040     xl = (x % 5 == 0 ? 1 : 0);
1041     yt = (y % 5 == 0 ? 1 : 0);
1042     xr = (x % 5 == 4 || x == ds->w-1 ? 1 : 0);
1043     yb = (y % 5 == 4 || y == ds->h-1 ? 1 : 0);
1044
1045     draw_rect(dr, TOCOORD(ds->w, x) + 1 + xl, TOCOORD(ds->h, y) + 1 + yt,
1046               TILE_SIZE - xl - xr - 1, TILE_SIZE - yt - yb - 1,
1047               (state == GRID_FULL ? COL_FULL :
1048                state == GRID_EMPTY ? COL_EMPTY : COL_UNKNOWN));
1049
1050     draw_update(dr, TOCOORD(ds->w, x), TOCOORD(ds->h, y),
1051                 TILE_SIZE, TILE_SIZE);
1052 }
1053
1054 static void draw_numbers(drawing *dr, game_drawstate *ds, game_state *state,
1055                          int colour)
1056 {
1057     int i, j;
1058
1059     /*
1060      * Draw the numbers.
1061      */
1062     for (i = 0; i < state->w + state->h; i++) {
1063         int rowlen = state->rowlen[i];
1064         int *rowdata = state->rowdata + state->rowsize * i;
1065         int nfit;
1066
1067         /*
1068          * Normally I space the numbers out by the same
1069          * distance as the tile size. However, if there are
1070          * more numbers than available spaces, I have to squash
1071          * them up a bit.
1072          */
1073         nfit = max(rowlen, TLBORDER(state->h))-1;
1074         assert(nfit > 0);
1075
1076         for (j = 0; j < rowlen; j++) {
1077             int x, y;
1078             char str[80];
1079
1080             if (i < state->w) {
1081                 x = TOCOORD(state->w, i);
1082                 y = BORDER + TILE_SIZE * (TLBORDER(state->h)-1);
1083                 y -= ((rowlen-j-1)*TILE_SIZE) * (TLBORDER(state->h)-1) / nfit;
1084             } else {
1085                 y = TOCOORD(state->h, i - state->w);
1086                 x = BORDER + TILE_SIZE * (TLBORDER(state->w)-1);
1087                 x -= ((rowlen-j-1)*TILE_SIZE) * (TLBORDER(state->h)-1) / nfit;
1088             }
1089
1090             sprintf(str, "%d", rowdata[j]);
1091             draw_text(dr, x+TILE_SIZE/2, y+TILE_SIZE/2, FONT_VARIABLE,
1092                       TILE_SIZE/2, ALIGN_HCENTRE | ALIGN_VCENTRE, colour, str);
1093         }
1094     }
1095 }
1096
1097 static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate,
1098                         game_state *state, int dir, game_ui *ui,
1099                         float animtime, float flashtime)
1100 {
1101     int i, j;
1102     int x1, x2, y1, y2;
1103
1104     if (!ds->started) {
1105         /*
1106          * The initial contents of the window are not guaranteed
1107          * and can vary with front ends. To be on the safe side,
1108          * all games should start by drawing a big background-
1109          * colour rectangle covering the whole window.
1110          */
1111         draw_rect(dr, 0, 0, SIZE(ds->w), SIZE(ds->h), COL_BACKGROUND);
1112
1113         /*
1114          * Draw the numbers.
1115          */
1116         draw_numbers(dr, ds, state, COL_TEXT);
1117
1118         /*
1119          * Draw the grid outline.
1120          */
1121         draw_rect(dr, TOCOORD(ds->w, 0) - 1, TOCOORD(ds->h, 0) - 1,
1122                   ds->w * TILE_SIZE + 3, ds->h * TILE_SIZE + 3,
1123                   COL_GRID);
1124
1125         ds->started = TRUE;
1126
1127         draw_update(dr, 0, 0, SIZE(ds->w), SIZE(ds->h));
1128     }
1129
1130     if (ui->dragging) {
1131         x1 = min(ui->drag_start_x, ui->drag_end_x);
1132         x2 = max(ui->drag_start_x, ui->drag_end_x);
1133         y1 = min(ui->drag_start_y, ui->drag_end_y);
1134         y2 = max(ui->drag_start_y, ui->drag_end_y);
1135     } else {
1136         x1 = x2 = y1 = y2 = -1;        /* placate gcc warnings */
1137     }
1138
1139     /*
1140      * Now draw any grid squares which have changed since last
1141      * redraw.
1142      */
1143     for (i = 0; i < ds->h; i++) {
1144         for (j = 0; j < ds->w; j++) {
1145             int val;
1146
1147             /*
1148              * Work out what state this square should be drawn in,
1149              * taking any current drag operation into account.
1150              */
1151             if (ui->dragging && x1 <= j && j <= x2 && y1 <= i && i <= y2)
1152                 val = ui->state;
1153             else
1154                 val = state->grid[i * state->w + j];
1155
1156             /*
1157              * Briefly invert everything twice during a completion
1158              * flash.
1159              */
1160             if (flashtime > 0 &&
1161                 (flashtime <= FLASH_TIME/3 || flashtime >= FLASH_TIME*2/3) &&
1162                 val != GRID_UNKNOWN)
1163                 val = (GRID_FULL ^ GRID_EMPTY) ^ val;
1164
1165             if (ds->visible[i * ds->w + j] != val) {
1166                 grid_square(dr, ds, i, j, val);
1167                 ds->visible[i * ds->w + j] = val;
1168             }
1169         }
1170     }
1171 }
1172
1173 static float game_anim_length(game_state *oldstate,
1174                               game_state *newstate, int dir, game_ui *ui)
1175 {
1176     return 0.0F;
1177 }
1178
1179 static float game_flash_length(game_state *oldstate,
1180                                game_state *newstate, int dir, game_ui *ui)
1181 {
1182     if (!oldstate->completed && newstate->completed &&
1183         !oldstate->cheated && !newstate->cheated)
1184         return FLASH_TIME;
1185     return 0.0F;
1186 }
1187
1188 static int game_timing_state(game_state *state, game_ui *ui)
1189 {
1190     return TRUE;
1191 }
1192
1193 static void game_print_size(game_params *params, float *x, float *y)
1194 {
1195     int pw, ph;
1196
1197     /*
1198      * I'll use 5mm squares by default.
1199      */
1200     game_compute_size(params, 500, &pw, &ph);
1201     *x = pw / 100.0;
1202     *y = ph / 100.0;
1203 }
1204
1205 static void game_print(drawing *dr, game_state *state, int tilesize)
1206 {
1207     int w = state->w, h = state->h;
1208     int ink = print_mono_colour(dr, 0);
1209     int x, y;
1210
1211     /* Ick: fake up `ds->tilesize' for macro expansion purposes */
1212     game_drawstate ads, *ds = &ads;
1213     game_set_size(dr, ds, NULL, tilesize);
1214
1215     /*
1216      * Border.
1217      */
1218     print_line_width(dr, TILE_SIZE / 16);
1219     draw_rect_outline(dr, TOCOORD(w, 0), TOCOORD(h, 0),
1220                       w*TILE_SIZE, h*TILE_SIZE, ink);
1221
1222     /*
1223      * Grid.
1224      */
1225     for (x = 1; x < w; x++) {
1226         print_line_width(dr, TILE_SIZE / (x % 5 ? 128 : 24));
1227         draw_line(dr, TOCOORD(w, x), TOCOORD(h, 0),
1228                   TOCOORD(w, x), TOCOORD(h, h), ink);
1229     }
1230     for (y = 1; y < h; y++) {
1231         print_line_width(dr, TILE_SIZE / (y % 5 ? 128 : 24));
1232         draw_line(dr, TOCOORD(w, 0), TOCOORD(h, y),
1233                   TOCOORD(w, w), TOCOORD(h, y), ink);
1234     }
1235
1236     /*
1237      * Clues.
1238      */
1239     draw_numbers(dr, ds, state, ink);
1240
1241     /*
1242      * Solution.
1243      */
1244     print_line_width(dr, TILE_SIZE / 128);
1245     for (y = 0; y < h; y++)
1246         for (x = 0; x < w; x++) {
1247             if (state->grid[y*w+x] == GRID_FULL)
1248                 draw_rect(dr, TOCOORD(w, x), TOCOORD(h, y),
1249                           TILE_SIZE, TILE_SIZE, ink);
1250             else if (state->grid[y*w+x] == GRID_EMPTY)
1251                 draw_circle(dr, TOCOORD(w, x) + TILE_SIZE/2,
1252                             TOCOORD(h, y) + TILE_SIZE/2,
1253                             TILE_SIZE/12, ink, ink);
1254         }
1255 }
1256
1257 #ifdef COMBINED
1258 #define thegame pattern
1259 #endif
1260
1261 const struct game thegame = {
1262     "Pattern", "games.pattern", "pattern",
1263     default_params,
1264     game_fetch_preset,
1265     decode_params,
1266     encode_params,
1267     free_params,
1268     dup_params,
1269     TRUE, game_configure, custom_params,
1270     validate_params,
1271     new_game_desc,
1272     validate_desc,
1273     new_game,
1274     dup_game,
1275     free_game,
1276     TRUE, solve_game,
1277     FALSE, game_can_format_as_text_now, game_text_format,
1278     new_ui,
1279     free_ui,
1280     encode_ui,
1281     decode_ui,
1282     game_changed_state,
1283     interpret_move,
1284     execute_move,
1285     PREFERRED_TILE_SIZE, game_compute_size, game_set_size,
1286     game_colours,
1287     game_new_drawstate,
1288     game_free_drawstate,
1289     game_redraw,
1290     game_anim_length,
1291     game_flash_length,
1292     TRUE, FALSE, game_print_size, game_print,
1293     FALSE,                             /* wants_statusbar */
1294     FALSE, game_timing_state,
1295     REQUIRE_RBUTTON,                   /* flags */
1296 };
1297
1298 #ifdef STANDALONE_SOLVER
1299
1300 int main(int argc, char **argv)
1301 {
1302     game_params *p;
1303     game_state *s;
1304     char *id = NULL, *desc, *err;
1305
1306     while (--argc > 0) {
1307         char *p = *++argv;
1308         if (*p == '-') {
1309             fprintf(stderr, "%s: unrecognised option `%s'\n", argv[0], p);
1310             return 1;
1311         } else {
1312             id = p;
1313         }
1314     }
1315
1316     if (!id) {
1317         fprintf(stderr, "usage: %s <game_id>\n", argv[0]);
1318         return 1;
1319     }
1320
1321     desc = strchr(id, ':');
1322     if (!desc) {
1323         fprintf(stderr, "%s: game id expects a colon in it\n", argv[0]);
1324         return 1;
1325     }
1326     *desc++ = '\0';
1327
1328     p = default_params();
1329     decode_params(p, id);
1330     err = validate_desc(p, desc);
1331     if (err) {
1332         fprintf(stderr, "%s: %s\n", argv[0], err);
1333         return 1;
1334     }
1335     s = new_game(NULL, p, desc);
1336
1337     {
1338         int w = p->w, h = p->h, i, j, done_any, max;
1339         unsigned char *matrix, *workspace;
1340         int *rowdata;
1341
1342         matrix = snewn(w*h, unsigned char);
1343         max = max(w, h);
1344         workspace = snewn(max*3, unsigned char);
1345         rowdata = snewn(max+1, int);
1346
1347         memset(matrix, 0, w*h);
1348
1349         do {
1350             done_any = 0;
1351             for (i=0; i<h; i++) {
1352                 memcpy(rowdata, s->rowdata + s->rowsize*(w+i),
1353                        max*sizeof(int));
1354                 rowdata[s->rowlen[w+i]] = 0;
1355                 done_any |= do_row(workspace, workspace+max, workspace+2*max,
1356                                    matrix+i*w, w, 1, rowdata);
1357             }
1358             for (i=0; i<w; i++) {
1359                 memcpy(rowdata, s->rowdata + s->rowsize*i, max*sizeof(int));
1360                 rowdata[s->rowlen[i]] = 0;
1361                 done_any |= do_row(workspace, workspace+max, workspace+2*max,
1362                                    matrix+i, h, w, rowdata);
1363             }
1364         } while (done_any);
1365
1366         for (i = 0; i < h; i++) {
1367             for (j = 0; j < w; j++) {
1368                 int c = (matrix[i*w+j] == UNKNOWN ? '?' :
1369                          matrix[i*w+j] == BLOCK ? '#' :
1370                          matrix[i*w+j] == DOT ? '.' :
1371                          '!');
1372                 putchar(c);
1373             }
1374             printf("\n");
1375         }
1376     }
1377
1378     return 0;
1379 }
1380
1381 #endif