mdw@git.distorted.org.uk Git - sgt/puzzles/blob - fifteen.c

   1 /*
   2  * fifteen.c: standard 15-puzzle.
   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 #define TILE_SIZE 48
  15 #define BORDER    (TILE_SIZE / 2)
  16 #define HIGHLIGHT_WIDTH (TILE_SIZE / 20)
  17 #define COORD(x)  ( (x) * TILE_SIZE + BORDER )
  18 #define FROMCOORD(x)  ( ((x) - BORDER + TILE_SIZE) / TILE_SIZE - 1 )
  19
  20 #define ANIM_TIME 0.13F
  21 #define FLASH_FRAME 0.13F
  22
  23 #define X(state, i) ( (i) % (state)->w )
  24 #define Y(state, i) ( (i) / (state)->w )
  25 #define C(state, x, y) ( (y) * (state)->w + (x) )
  26
  27 enum {
  28     COL_BACKGROUND,
  29     COL_TEXT,
  30     COL_HIGHLIGHT,
  31     COL_LOWLIGHT,
  32     NCOLOURS
  33 };
  34
  35 struct game_params {
  36     int w, h;
  37 };
  38
  39 struct game_state {
  40     int w, h, n;
  41     int *tiles;
  42     int gap_pos;
  43     int completed;
  44     int just_used_solve;               /* used to suppress undo animation */
  45     int used_solve;                    /* used to suppress completion flash */
  46     int movecount;
  47 };
  48
  49 static game_params *default_params(void)
  50 {
  51     game_params *ret = snew(game_params);
  52
  53     ret->w = ret->h = 4;
  54
  55     return ret;
  56 }
  57
  58 static int game_fetch_preset(int i, char **name, game_params **params)
  59 {
  60     return FALSE;
  61 }
  62
  63 static void free_params(game_params *params)
  64 {
  65     sfree(params);
  66 }
  67
  68 static game_params *dup_params(game_params *params)
  69 {
  70     game_params *ret = snew(game_params);
  71     *ret = *params;                    /* structure copy */
  72     return ret;
  73 }
  74
  75 static game_params *decode_params(char const *string)
  76 {
  77     game_params *ret = default_params();
  78
  79     ret->w = ret->h = atoi(string);
  80     while (*string && isdigit(*string)) string++;
  81     if (*string == 'x') {
  82         string++;
  83         ret->h = atoi(string);
  84     }
  85
  86     return ret;
  87 }
  88
  89 static char *encode_params(game_params *params)
  90 {
  91     char data[256];
  92
  93     sprintf(data, "%dx%d", params->w, params->h);
  94
  95     return dupstr(data);
  96 }
  97
  98 static config_item *game_configure(game_params *params)
  99 {
 100     config_item *ret;
 101     char buf[80];
 102
 103     ret = snewn(3, config_item);
 104
 105     ret[0].name = "Width";
 106     ret[0].type = C_STRING;
 107     sprintf(buf, "%d", params->w);
 108     ret[0].sval = dupstr(buf);
 109     ret[0].ival = 0;
 110
 111     ret[1].name = "Height";
 112     ret[1].type = C_STRING;
 113     sprintf(buf, "%d", params->h);
 114     ret[1].sval = dupstr(buf);
 115     ret[1].ival = 0;
 116
 117     ret[2].name = NULL;
 118     ret[2].type = C_END;
 119     ret[2].sval = NULL;
 120     ret[2].ival = 0;
 121
 122     return ret;
 123 }
 124
 125 static game_params *custom_params(config_item *cfg)
 126 {
 127     game_params *ret = snew(game_params);
 128
 129     ret->w = atoi(cfg[0].sval);
 130     ret->h = atoi(cfg[1].sval);
 131
 132     return ret;
 133 }
 134
 135 static char *validate_params(game_params *params)
 136 {
 137     if (params->w < 2 && params->h < 2)
 138         return "Width and height must both be at least two";
 139
 140     return NULL;
 141 }
 142
 143 static int perm_parity(int *perm, int n)
 144 {
 145     int i, j, ret;
 146
 147     ret = 0;
 148
 149     for (i = 0; i < n-1; i++)
 150         for (j = i+1; j < n; j++)
 151             if (perm[i] > perm[j])
 152                 ret = !ret;
 153
 154     return ret;
 155 }
 156
 157 static char *new_game_seed(game_params *params, random_state *rs,
 158                            game_aux_info **aux)
 159 {
 160     int gap, n, i, x;
 161     int x1, x2, p1, p2, parity;
 162     int *tiles, *used;
 163     char *ret;
 164     int retlen;
 165
 166     n = params->w * params->h;
 167
 168     tiles = snewn(n, int);
 169     used = snewn(n, int);
 170
 171     for (i = 0; i < n; i++) {
 172         tiles[i] = -1;
 173         used[i] = FALSE;
 174     }
 175
 176     gap = random_upto(rs, n);
 177     tiles[gap] = 0;
 178     used[0] = TRUE;
 179
 180     /*
 181      * Place everything else except the last two tiles.
 182      */
 183     for (x = 0, i = n-1; i > 2; i--) {
 184         int k = random_upto(rs, i);
 185         int j;
 186
 187         for (j = 0; j < n; j++)
 188             if (!used[j] && (k-- == 0))
 189                 break;
 190
 191         assert(j < n && !used[j]);
 192         used[j] = TRUE;
 193
 194         while (tiles[x] >= 0)
 195             x++;
 196         assert(x < n);
 197         tiles[x] = j;
 198     }
 199
 200     /*
 201      * Find the last two locations, and the last two pieces.
 202      */
 203     while (tiles[x] >= 0)
 204         x++;
 205     assert(x < n);
 206     x1 = x;
 207     x++;
 208     while (tiles[x] >= 0)
 209         x++;
 210     assert(x < n);
 211     x2 = x;
 212
 213     for (i = 0; i < n; i++)
 214         if (!used[i])
 215             break;
 216     p1 = i;
 217     for (i = p1+1; i < n; i++)
 218         if (!used[i])
 219             break;
 220     p2 = i;
 221
 222     /*
 223      * Determine the required parity of the overall permutation.
 224      * This is the XOR of:
 225      *
 226      *  - The chessboard parity ((x^y)&1) of the gap square. The
 227      *    bottom right counts as even.
 228      *
 229      *  - The parity of n. (The target permutation is 1,...,n-1,0
 230      *    rather than 0,...,n-1; this is a cyclic permutation of
 231      *    the starting point and hence is odd iff n is even.)
 232      */
 233     parity = ((X(params, gap) - (params->w-1)) ^
 234               (Y(params, gap) - (params->h-1)) ^
 235               (n+1)) & 1;
 236
 237     /*
 238      * Try the last two tiles one way round. If that fails, swap
 239      * them.
 240      */
 241     tiles[x1] = p1;
 242     tiles[x2] = p2;
 243     if (perm_parity(tiles, n) != parity) {
 244         tiles[x1] = p2;
 245         tiles[x2] = p1;
 246         assert(perm_parity(tiles, n) == parity);
 247     }
 248
 249     /*
 250      * Now construct the game seed, by describing the tile array as
 251      * a simple sequence of comma-separated integers.
 252      */
 253     ret = NULL;
 254     retlen = 0;
 255     for (i = 0; i < n; i++) {
 256         char buf[80];
 257         int k;
 258
 259         k = sprintf(buf, "%d,", tiles[i]);
 260
 261         ret = sresize(ret, retlen + k + 1, char);
 262         strcpy(ret + retlen, buf);
 263         retlen += k;
 264     }
 265     ret[retlen-1] = '\0';              /* delete last comma */
 266
 267     sfree(tiles);
 268     sfree(used);
 269
 270     return ret;
 271 }
 272
 273 static void game_free_aux_info(game_aux_info *aux)
 274 {
 275     assert(!"Shouldn't happen");
 276 }
 277
 278 static char *validate_seed(game_params *params, char *seed)
 279 {
 280     char *p, *err;
 281     int i, area;
 282     int *used;
 283
 284     area = params->w * params->h;
 285     p = seed;
 286     err = NULL;
 287
 288     used = snewn(area, int);
 289     for (i = 0; i < area; i++)
 290         used[i] = FALSE;
 291
 292     for (i = 0; i < area; i++) {
 293         char *q = p;
 294         int n;
 295
 296         if (*p < '0' || *p > '9') {
 297             err = "Not enough numbers in string";
 298             goto leave;
 299         }
 300         while (*p >= '0' && *p <= '9')
 301             p++;
 302         if (i < area-1 && *p != ',') {
 303             err = "Expected comma after number";
 304             goto leave;
 305         }
 306         else if (i == area-1 && *p) {
 307             err = "Excess junk at end of string";
 308             goto leave;
 309         }
 310         n = atoi(q);
 311         if (n < 0 || n >= area) {
 312             err = "Number out of range";
 313             goto leave;
 314         }
 315         if (used[n]) {
 316             err = "Number used twice";
 317             goto leave;
 318         }
 319         used[n] = TRUE;
 320
 321         if (*p) p++;                   /* eat comma */
 322     }
 323
 324     leave:
 325     sfree(used);
 326     return err;
 327 }
 328
 329 static game_state *new_game(game_params *params, char *seed)
 330 {
 331     game_state *state = snew(game_state);
 332     int i;
 333     char *p;
 334
 335     state->w = params->w;
 336     state->h = params->h;
 337     state->n = params->w * params->h;
 338     state->tiles = snewn(state->n, int);
 339
 340     state->gap_pos = 0;
 341     p = seed;
 342     i = 0;
 343     for (i = 0; i < state->n; i++) {
 344         assert(*p);
 345         state->tiles[i] = atoi(p);
 346         if (state->tiles[i] == 0)
 347             state->gap_pos = i;
 348         while (*p && *p != ',')
 349             p++;
 350         if (*p) p++;                   /* eat comma */
 351     }
 352     assert(!*p);
 353     assert(state->tiles[state->gap_pos] == 0);
 354
 355     state->completed = state->movecount = 0;
 356     state->used_solve = state->just_used_solve = FALSE;
 357
 358     return state;
 359 }
 360
 361 static game_state *dup_game(game_state *state)
 362 {
 363     game_state *ret = snew(game_state);
 364
 365     ret->w = state->w;
 366     ret->h = state->h;
 367     ret->n = state->n;
 368     ret->tiles = snewn(state->w * state->h, int);
 369     memcpy(ret->tiles, state->tiles, state->w * state->h * sizeof(int));
 370     ret->gap_pos = state->gap_pos;
 371     ret->completed = state->completed;
 372     ret->movecount = state->movecount;
 373     ret->used_solve = state->used_solve;
 374     ret->just_used_solve = state->just_used_solve;
 375
 376     return ret;
 377 }
 378
 379 static void free_game(game_state *state)
 380 {
 381     sfree(state);
 382 }
 383
 384 static game_state *solve_game(game_state *state, game_aux_info *aux,
 385                               char **error)
 386 {
 387     game_state *ret = dup_game(state);
 388     int i;
 389
 390     /*
 391      * Simply replace the grid with a solved one. For this game,
 392      * this isn't a useful operation for actually telling the user
 393      * what they should have done, but it is useful for
 394      * conveniently being able to get hold of a clean state from
 395      * which to practise manoeuvres.
 396      */
 397     for (i = 0; i < ret->n; i++)
 398         ret->tiles[i] = (i+1) % ret->n;
 399     ret->gap_pos = ret->n-1;
 400     ret->used_solve = ret->just_used_solve = TRUE;
 401     ret->completed = ret->movecount;
 402
 403     return ret;
 404 }
 405
 406 static char *game_text_format(game_state *state)
 407 {
 408     char *ret, *p, buf[80];
 409     int x, y, col, maxlen;
 410
 411     /*
 412      * First work out how many characters we need to display each
 413      * number.
 414      */
 415     col = sprintf(buf, "%d", state->n-1);
 416
 417     /*
 418      * Now we know the exact total size of the grid we're going to
 419      * produce: it's got h rows, each containing w lots of col, w-1
 420      * spaces and a trailing newline.
 421      */
 422     maxlen = state->h * state->w * (col+1);
 423
 424     ret = snewn(maxlen+1, char);
 425     p = ret;
 426
 427     for (y = 0; y < state->h; y++) {
 428         for (x = 0; x < state->w; x++) {
 429             int v = state->tiles[state->w*y+x];
 430             if (v == 0)
 431                 sprintf(buf, "%*s", col, "");
 432             else
 433                 sprintf(buf, "%*d", col, v);
 434             memcpy(p, buf, col);
 435             p += col;
 436             if (x+1 == state->w)
 437                 *p++ = '\n';
 438             else
 439                 *p++ = ' ';
 440         }
 441     }
 442
 443     assert(p - ret == maxlen);
 444     *p = '\0';
 445     return ret;
 446 }
 447
 448 static game_ui *new_ui(game_state *state)
 449 {
 450     return NULL;
 451 }
 452
 453 static void free_ui(game_ui *ui)
 454 {
 455 }
 456
 457 static game_state *make_move(game_state *from, game_ui *ui,
 458                              int x, int y, int button)
 459 {
 460     int gx, gy, dx, dy, ux, uy, up, p;
 461     game_state *ret;
 462
 463     gx = X(from, from->gap_pos);
 464     gy = Y(from, from->gap_pos);
 465
 466     if (button == CURSOR_RIGHT && gx > 0)
 467         dx = gx - 1, dy = gy;
 468     else if (button == CURSOR_LEFT && gx < from->w-1)
 469         dx = gx + 1, dy = gy;
 470     else if (button == CURSOR_DOWN && gy > 0)
 471         dy = gy - 1, dx = gx;
 472     else if (button == CURSOR_UP && gy < from->h-1)
 473         dy = gy + 1, dx = gx;
 474     else if (button == LEFT_BUTTON) {
 475         dx = FROMCOORD(x);
 476         dy = FROMCOORD(y);
 477         if (dx < 0 || dx >= from->w || dy < 0 || dy >= from->h)
 478             return NULL;               /* out of bounds */
 479         /*
 480          * Any click location should be equal to the gap location
 481          * in _precisely_ one coordinate.
 482          */
 483         if ((dx == gx && dy == gy) || (dx != gx && dy != gy))
 484             return NULL;
 485     } else
 486         return NULL;                   /* no move */
 487
 488     /*
 489      * Find the unit displacement from the original gap
 490      * position towards this one.
 491      */
 492     ux = (dx < gx ? -1 : dx > gx ? +1 : 0);
 493     uy = (dy < gy ? -1 : dy > gy ? +1 : 0);
 494     up = C(from, ux, uy);
 495
 496     ret = dup_game(from);
 497     ret->just_used_solve = FALSE;      /* zero this in a hurry */
 498
 499     ret->gap_pos = C(from, dx, dy);
 500     assert(ret->gap_pos >= 0 && ret->gap_pos < ret->n);
 501
 502     ret->tiles[ret->gap_pos] = 0;
 503
 504     for (p = from->gap_pos; p != ret->gap_pos; p += up) {
 505         assert(p >= 0 && p < from->n);
 506         ret->tiles[p] = from->tiles[p + up];
 507         ret->movecount++;
 508     }
 509
 510     /*
 511      * See if the game has been completed.
 512      */
 513     if (!ret->completed) {
 514         ret->completed = ret->movecount;
 515         for (p = 0; p < ret->n; p++)
 516             if (ret->tiles[p] != (p < ret->n-1 ? p+1 : 0))
 517                 ret->completed = 0;
 518     }
 519
 520     return ret;
 521 }
 522
 523 /* ----------------------------------------------------------------------
 524  * Drawing routines.
 525  */
 526
 527 struct game_drawstate {
 528     int started;
 529     int w, h, bgcolour;
 530     int *tiles;
 531 };
 532
 533 static void game_size(game_params *params, int *x, int *y)
 534 {
 535     *x = TILE_SIZE * params->w + 2 * BORDER;
 536     *y = TILE_SIZE * params->h + 2 * BORDER;
 537 }
 538
 539 static float *game_colours(frontend *fe, game_state *state, int *ncolours)
 540 {
 541     float *ret = snewn(3 * NCOLOURS, float);
 542     int i;
 543     float max;
 544
 545     frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
 546
 547     /*
 548      * Drop the background colour so that the highlight is
 549      * noticeably brighter than it while still being under 1.
 550      */
 551     max = ret[COL_BACKGROUND*3];
 552     for (i = 1; i < 3; i++)
 553         if (ret[COL_BACKGROUND*3+i] > max)
 554             max = ret[COL_BACKGROUND*3+i];
 555     if (max * 1.2F > 1.0F) {
 556         for (i = 0; i < 3; i++)
 557             ret[COL_BACKGROUND*3+i] /= (max * 1.2F);
 558     }
 559
 560     for (i = 0; i < 3; i++) {
 561         ret[COL_HIGHLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 1.2F;
 562         ret[COL_LOWLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 0.8F;
 563         ret[COL_TEXT * 3 + i] = 0.0;
 564     }
 565
 566     *ncolours = NCOLOURS;
 567     return ret;
 568 }
 569
 570 static game_drawstate *game_new_drawstate(game_state *state)
 571 {
 572     struct game_drawstate *ds = snew(struct game_drawstate);
 573     int i;
 574
 575     ds->started = FALSE;
 576     ds->w = state->w;
 577     ds->h = state->h;
 578     ds->bgcolour = COL_BACKGROUND;
 579     ds->tiles = snewn(ds->w*ds->h, int);
 580     for (i = 0; i < ds->w*ds->h; i++)
 581         ds->tiles[i] = -1;
 582
 583     return ds;
 584 }
 585
 586 static void game_free_drawstate(game_drawstate *ds)
 587 {
 588     sfree(ds->tiles);
 589     sfree(ds);
 590 }
 591
 592 static void draw_tile(frontend *fe, game_state *state, int x, int y,
 593                       int tile, int flash_colour)
 594 {
 595     if (tile == 0) {
 596         draw_rect(fe, x, y, TILE_SIZE, TILE_SIZE,
 597                   flash_colour);
 598     } else {
 599         int coords[6];
 600         char str[40];
 601
 602         coords[0] = x + TILE_SIZE - 1;
 603         coords[1] = y + TILE_SIZE - 1;
 604         coords[2] = x + TILE_SIZE - 1;
 605         coords[3] = y;
 606         coords[4] = x;
 607         coords[5] = y + TILE_SIZE - 1;
 608         draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
 609         draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);
 610
 611         coords[0] = x;
 612         coords[1] = y;
 613         draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
 614         draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);
 615
 616         draw_rect(fe, x + HIGHLIGHT_WIDTH, y + HIGHLIGHT_WIDTH,
 617                   TILE_SIZE - 2*HIGHLIGHT_WIDTH, TILE_SIZE - 2*HIGHLIGHT_WIDTH,
 618                   flash_colour);
 619
 620         sprintf(str, "%d", tile);
 621         draw_text(fe, x + TILE_SIZE/2, y + TILE_SIZE/2,
 622                   FONT_VARIABLE, TILE_SIZE/3, ALIGN_VCENTRE | ALIGN_HCENTRE,
 623                   COL_TEXT, str);
 624     }
 625     draw_update(fe, x, y, TILE_SIZE, TILE_SIZE);
 626 }
 627
 628 static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate,
 629                  game_state *state, int dir, game_ui *ui,
 630                  float animtime, float flashtime)
 631 {
 632     int i, pass, bgcolour;
 633
 634     if (flashtime > 0) {
 635         int frame = (int)(flashtime / FLASH_FRAME);
 636         bgcolour = (frame % 2 ? COL_LOWLIGHT : COL_HIGHLIGHT);
 637     } else
 638         bgcolour = COL_BACKGROUND;
 639
 640     if (!ds->started) {
 641         int coords[6];
 642
 643         draw_rect(fe, 0, 0,
 644                   TILE_SIZE * state->w + 2 * BORDER,
 645                   TILE_SIZE * state->h + 2 * BORDER, COL_BACKGROUND);
 646         draw_update(fe, 0, 0,
 647                     TILE_SIZE * state->w + 2 * BORDER,
 648                     TILE_SIZE * state->h + 2 * BORDER);
 649
 650         /*
 651          * Recessed area containing the whole puzzle.
 652          */
 653         coords[0] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
 654         coords[1] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
 655         coords[2] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
 656         coords[3] = COORD(0) - HIGHLIGHT_WIDTH;
 657         coords[4] = COORD(0) - HIGHLIGHT_WIDTH;
 658         coords[5] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
 659         draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
 660         draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);
 661
 662         coords[1] = COORD(0) - HIGHLIGHT_WIDTH;
 663         coords[0] = COORD(0) - HIGHLIGHT_WIDTH;
 664         draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
 665         draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);
 666
 667         ds->started = TRUE;
 668     }
 669
 670     /*
 671      * Now draw each tile. We do this in two passes to make
 672      * animation easy.
 673      */
 674     for (pass = 0; pass < 2; pass++) {
 675         for (i = 0; i < state->n; i++) {
 676             int t, t0;
 677             /*
 678              * Figure out what should be displayed at this
 679              * location. It's either a simple tile, or it's a
 680              * transition between two tiles (in which case we say
 681              * -1 because it must always be drawn).
 682              */
 683
 684             if (oldstate && oldstate->tiles[i] != state->tiles[i])
 685                 t = -1;
 686             else
 687                 t = state->tiles[i];
 688
 689             t0 = t;
 690
 691             if (ds->bgcolour != bgcolour ||   /* always redraw when flashing */
 692                 ds->tiles[i] != t || ds->tiles[i] == -1 || t == -1) {
 693                 int x, y;
 694
 695                 /*
 696                  * Figure out what to _actually_ draw, and where to
 697                  * draw it.
 698                  */
 699                 if (t == -1) {
 700                     int x0, y0, x1, y1;
 701                     int j;
 702
 703                     /*
 704                      * On the first pass, just blank the tile.
 705                      */
 706                     if (pass == 0) {
 707                         x = COORD(X(state, i));
 708                         y = COORD(Y(state, i));
 709                         t = 0;
 710                     } else {
 711                         float c;
 712
 713                         t = state->tiles[i];
 714
 715                         /*
 716                          * Don't bother moving the gap; just don't
 717                          * draw it.
 718                          */
 719                         if (t == 0)
 720                             continue;
 721
 722                         /*
 723                          * Find the coordinates of this tile in the old and
 724                          * new states.
 725                          */
 726                         x1 = COORD(X(state, i));
 727                         y1 = COORD(Y(state, i));
 728                         for (j = 0; j < oldstate->n; j++)
 729                             if (oldstate->tiles[j] == state->tiles[i])
 730                                 break;
 731                         assert(j < oldstate->n);
 732                         x0 = COORD(X(state, j));
 733                         y0 = COORD(Y(state, j));
 734
 735                         c = (animtime / ANIM_TIME);
 736                         if (c < 0.0F) c = 0.0F;
 737                         if (c > 1.0F) c = 1.0F;
 738
 739                         x = x0 + (int)(c * (x1 - x0));
 740                         y = y0 + (int)(c * (y1 - y0));
 741                     }
 742
 743                 } else {
 744                     if (pass == 0)
 745                         continue;
 746                     x = COORD(X(state, i));
 747                     y = COORD(Y(state, i));
 748                 }
 749
 750                 draw_tile(fe, state, x, y, t, bgcolour);
 751             }
 752             ds->tiles[i] = t0;
 753         }
 754     }
 755     ds->bgcolour = bgcolour;
 756
 757     /*
 758      * Update the status bar.
 759      */
 760     {
 761         char statusbuf[256];
 762
 763         /*
 764          * Don't show the new status until we're also showing the
 765          * new _state_ - after the game animation is complete.
 766          */
 767         if (oldstate)
 768             state = oldstate;
 769
 770         if (state->used_solve)
 771             sprintf(statusbuf, "Moves since auto-solve: %d",
 772                     state->movecount - state->completed);
 773         else
 774             sprintf(statusbuf, "%sMoves: %d",
 775                     (state->completed ? "COMPLETED! " : ""),
 776                     (state->completed ? state->completed : state->movecount));
 777
 778         status_bar(fe, statusbuf);
 779     }
 780 }
 781
 782 static float game_anim_length(game_state *oldstate,
 783                               game_state *newstate, int dir)
 784 {
 785     if ((dir > 0 && newstate->just_used_solve) ||
 786         (dir < 0 && oldstate->just_used_solve))
 787         return 0.0F;
 788     else
 789         return ANIM_TIME;
 790 }
 791
 792 static float game_flash_length(game_state *oldstate,
 793                                game_state *newstate, int dir)
 794 {
 795     if (!oldstate->completed && newstate->completed &&
 796         !oldstate->used_solve && !newstate->used_solve)
 797         return 2 * FLASH_FRAME;
 798     else
 799         return 0.0F;
 800 }
 801
 802 static int game_wants_statusbar(void)
 803 {
 804     return TRUE;
 805 }
 806
 807 #ifdef COMBINED
 808 #define thegame fifteen
 809 #endif
 810
 811 const struct game thegame = {
 812     "Fifteen", "games.fifteen",
 813     default_params,
 814     game_fetch_preset,
 815     decode_params,
 816     encode_params,
 817     free_params,
 818     dup_params,
 819     TRUE, game_configure, custom_params,
 820     validate_params,
 821     new_game_seed,
 822     game_free_aux_info,
 823     validate_seed,
 824     new_game,
 825     dup_game,
 826     free_game,
 827     TRUE, solve_game,
 828     TRUE, game_text_format,
 829     new_ui,
 830     free_ui,
 831     make_move,
 832     game_size,
 833     game_colours,
 834     game_new_drawstate,
 835     game_free_drawstate,
 836     game_redraw,
 837     game_anim_length,
 838     game_flash_length,
 839     game_wants_statusbar,
 840 };