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

   1 /*
   2  * sixteen.c: `16-puzzle', a sliding-tiles jigsaw which differs
   3  * from the 15-puzzle in that you toroidally rotate a row or column
   4  * at a time.
   5  */
   6
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <assert.h>
  11 #include <math.h>
  12
  13 #include "puzzles.h"
  14
  15 const char *const game_name = "Sixteen";
  16 const int game_can_configure = TRUE;
  17
  18 #define TILE_SIZE 48
  19 #define BORDER    TILE_SIZE            /* big border to fill with arrows */
  20 #define HIGHLIGHT_WIDTH (TILE_SIZE / 20)
  21 #define COORD(x)  ( (x) * TILE_SIZE + BORDER )
  22 #define FROMCOORD(x)  ( ((x) - BORDER + 2*TILE_SIZE) / TILE_SIZE - 2 )
  23
  24 #define ANIM_TIME 0.13F
  25 #define FLASH_FRAME 0.13F
  26
  27 #define X(state, i) ( (i) % (state)->w )
  28 #define Y(state, i) ( (i) / (state)->w )
  29 #define C(state, x, y) ( (y) * (state)->w + (x) )
  30
  31 enum {
  32     COL_BACKGROUND,
  33     COL_TEXT,
  34     COL_HIGHLIGHT,
  35     COL_LOWLIGHT,
  36     NCOLOURS
  37 };
  38
  39 struct game_params {
  40     int w, h;
  41 };
  42
  43 struct game_state {
  44     int w, h, n;
  45     int *tiles;
  46     int completed;
  47     int movecount;
  48     int last_movement_sense;
  49 };
  50
  51 game_params *default_params(void)
  52 {
  53     game_params *ret = snew(game_params);
  54
  55     ret->w = ret->h = 4;
  56
  57     return ret;
  58 }
  59
  60 int game_fetch_preset(int i, char **name, game_params **params)
  61 {
  62     game_params *ret;
  63     int w, h;
  64     char buf[80];
  65
  66     switch (i) {
  67       case 0: w = 3, h = 3; break;
  68       case 1: w = 4, h = 3; break;
  69       case 2: w = 4, h = 4; break;
  70       case 3: w = 5, h = 4; break;
  71       case 4: w = 5, h = 5; break;
  72       default: return FALSE;
  73     }
  74
  75     sprintf(buf, "%dx%d", w, h);
  76     *name = dupstr(buf);
  77     *params = ret = snew(game_params);
  78     ret->w = w;
  79     ret->h = h;
  80     return TRUE;
  81 }
  82
  83 void free_params(game_params *params)
  84 {
  85     sfree(params);
  86 }
  87
  88 game_params *dup_params(game_params *params)
  89 {
  90     game_params *ret = snew(game_params);
  91     *ret = *params;                    /* structure copy */
  92     return ret;
  93 }
  94
  95 config_item *game_configure(game_params *params)
  96 {
  97     config_item *ret;
  98     char buf[80];
  99
 100     ret = snewn(3, config_item);
 101
 102     ret[0].name = "Width";
 103     ret[0].type = C_STRING;
 104     sprintf(buf, "%d", params->w);
 105     ret[0].sval = dupstr(buf);
 106     ret[0].ival = 0;
 107
 108     ret[1].name = "Height";
 109     ret[1].type = C_STRING;
 110     sprintf(buf, "%d", params->h);
 111     ret[1].sval = dupstr(buf);
 112     ret[1].ival = 0;
 113
 114     ret[2].name = NULL;
 115     ret[2].type = C_END;
 116     ret[2].sval = NULL;
 117     ret[2].ival = 0;
 118
 119     return ret;
 120 }
 121
 122 game_params *custom_params(config_item *cfg)
 123 {
 124     game_params *ret = snew(game_params);
 125
 126     ret->w = atoi(cfg[0].sval);
 127     ret->h = atoi(cfg[1].sval);
 128
 129     return ret;
 130 }
 131
 132 char *validate_params(game_params *params)
 133 {
 134     if (params->w < 2 && params->h < 2)
 135         return "Width and height must both be at least two";
 136
 137     return NULL;
 138 }
 139
 140 int perm_parity(int *perm, int n)
 141 {
 142     int i, j, ret;
 143
 144     ret = 0;
 145
 146     for (i = 0; i < n-1; i++)
 147         for (j = i+1; j < n; j++)
 148             if (perm[i] > perm[j])
 149                 ret = !ret;
 150
 151     return ret;
 152 }
 153
 154 char *new_game_seed(game_params *params, random_state *rs)
 155 {
 156     int stop, n, i, x;
 157     int x1, x2, p1, p2;
 158     int *tiles, *used;
 159     char *ret;
 160     int retlen;
 161
 162     n = params->w * params->h;
 163
 164     tiles = snewn(n, int);
 165     used = snewn(n, int);
 166
 167     for (i = 0; i < n; i++) {
 168         tiles[i] = -1;
 169         used[i] = FALSE;
 170     }
 171
 172     /*
 173      * If both dimensions are odd, there is a parity constraint.
 174      */
 175     if (params->w & params->h & 1)
 176         stop = 2;
 177     else
 178         stop = 0;
 179
 180     /*
 181      * Place everything except (possibly) the last two tiles.
 182      */
 183     for (x = 0, i = n; i > stop; i--) {
 184         int k = i > 1 ? random_upto(rs, i) : 0;
 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     if (stop) {
 201         /*
 202          * Find the last two locations, and the last two pieces.
 203          */
 204         while (tiles[x] >= 0)
 205             x++;
 206         assert(x < n);
 207         x1 = x;
 208         x++;
 209         while (tiles[x] >= 0)
 210             x++;
 211         assert(x < n);
 212         x2 = x;
 213
 214         for (i = 0; i < n; i++)
 215             if (!used[i])
 216                 break;
 217         p1 = i;
 218         for (i = p1+1; i < n; i++)
 219             if (!used[i])
 220                 break;
 221         p2 = i;
 222
 223         /*
 224          * Try the last two tiles one way round. If that fails, swap
 225          * them.
 226          */
 227         tiles[x1] = p1;
 228         tiles[x2] = p2;
 229         if (perm_parity(tiles, n) != 0) {
 230             tiles[x1] = p2;
 231             tiles[x2] = p1;
 232             assert(perm_parity(tiles, n) == 0);
 233         }
 234     }
 235
 236     /*
 237      * Now construct the game seed, by describing the tile array as
 238      * a simple sequence of comma-separated integers.
 239      */
 240     ret = NULL;
 241     retlen = 0;
 242     for (i = 0; i < n; i++) {
 243         char buf[80];
 244         int k;
 245
 246         k = sprintf(buf, "%d,", tiles[i]+1);
 247
 248         ret = sresize(ret, retlen + k + 1, char);
 249         strcpy(ret + retlen, buf);
 250         retlen += k;
 251     }
 252     ret[retlen-1] = '\0';              /* delete last comma */
 253
 254     sfree(tiles);
 255     sfree(used);
 256
 257     return ret;
 258 }
 259
 260
 261 char *validate_seed(game_params *params, char *seed)
 262 {
 263     char *p, *err;
 264     int i, area;
 265     int *used;
 266
 267     area = params->w * params->h;
 268     p = seed;
 269     err = NULL;
 270
 271     used = snewn(area, int);
 272     for (i = 0; i < area; i++)
 273         used[i] = FALSE;
 274
 275     for (i = 0; i < area; i++) {
 276         char *q = p;
 277         int n;
 278
 279         if (*p < '0' || *p > '9') {
 280             err = "Not enough numbers in string";
 281             goto leave;
 282         }
 283         while (*p >= '0' && *p <= '9')
 284             p++;
 285         if (i < area-1 && *p != ',') {
 286             err = "Expected comma after number";
 287             goto leave;
 288         }
 289         else if (i == area-1 && *p) {
 290             err = "Excess junk at end of string";
 291             goto leave;
 292         }
 293         n = atoi(q);
 294         if (n < 1 || n > area) {
 295             err = "Number out of range";
 296             goto leave;
 297         }
 298         if (used[n-1]) {
 299             err = "Number used twice";
 300             goto leave;
 301         }
 302         used[n-1] = TRUE;
 303
 304         if (*p) p++;                   /* eat comma */
 305     }
 306
 307     leave:
 308     sfree(used);
 309     return err;
 310 }
 311
 312 game_state *new_game(game_params *params, char *seed)
 313 {
 314     game_state *state = snew(game_state);
 315     int i;
 316     char *p;
 317
 318     state->w = params->w;
 319     state->h = params->h;
 320     state->n = params->w * params->h;
 321     state->tiles = snewn(state->n, int);
 322
 323     p = seed;
 324     i = 0;
 325     for (i = 0; i < state->n; i++) {
 326         assert(*p);
 327         state->tiles[i] = atoi(p);
 328         while (*p && *p != ',')
 329             p++;
 330         if (*p) p++;                   /* eat comma */
 331     }
 332     assert(!*p);
 333
 334     state->completed = state->movecount = 0;
 335     state->last_movement_sense = 0;
 336
 337     return state;
 338 }
 339
 340 game_state *dup_game(game_state *state)
 341 {
 342     game_state *ret = snew(game_state);
 343
 344     ret->w = state->w;
 345     ret->h = state->h;
 346     ret->n = state->n;
 347     ret->tiles = snewn(state->w * state->h, int);
 348     memcpy(ret->tiles, state->tiles, state->w * state->h * sizeof(int));
 349     ret->completed = state->completed;
 350     ret->movecount = state->movecount;
 351     ret->last_movement_sense = state->last_movement_sense;
 352
 353     return ret;
 354 }
 355
 356 void free_game(game_state *state)
 357 {
 358     sfree(state);
 359 }
 360
 361 game_ui *new_ui(game_state *state)
 362 {
 363     return NULL;
 364 }
 365
 366 void free_ui(game_ui *ui)
 367 {
 368 }
 369
 370 game_state *make_move(game_state *from, game_ui *ui, int x, int y, int button)
 371 {
 372     int cx, cy;
 373     int dx, dy, tx, ty, n;
 374     game_state *ret;
 375
 376     if (button != LEFT_BUTTON)
 377         return NULL;
 378
 379     cx = FROMCOORD(x);
 380     cy = FROMCOORD(y);
 381     if (cx == -1 && cy >= 0 && cy < from->h)
 382         n = from->w, dx = +1, dy = 0;
 383     else if (cx == from->w && cy >= 0 && cy < from->h)
 384         n = from->w, dx = -1, dy = 0;
 385     else if (cy == -1 && cx >= 0 && cx < from->w)
 386         n = from->h, dy = +1, dx = 0;
 387     else if (cy == from->h && cx >= 0 && cx < from->w)
 388         n = from->h, dy = -1, dx = 0;
 389     else
 390         return NULL;                   /* invalid click location */
 391
 392     ret = dup_game(from);
 393
 394     do {
 395         cx += dx;
 396         cy += dy;
 397         tx = (cx + dx + from->w) % from->w;
 398         ty = (cy + dy + from->h) % from->h;
 399         ret->tiles[C(ret, cx, cy)] = from->tiles[C(from, tx, ty)];
 400     } while (--n > 0);
 401
 402     ret->movecount++;
 403
 404     ret->last_movement_sense = -(dx+dy);
 405
 406     /*
 407      * See if the game has been completed.
 408      */
 409     if (!ret->completed) {
 410         ret->completed = ret->movecount;
 411         for (n = 0; n < ret->n; n++)
 412             if (ret->tiles[n] != n+1)
 413                 ret->completed = FALSE;
 414     }
 415
 416     return ret;
 417 }
 418
 419 /* ----------------------------------------------------------------------
 420  * Drawing routines.
 421  */
 422
 423 struct game_drawstate {
 424     int started;
 425     int w, h, bgcolour;
 426     int *tiles;
 427 };
 428
 429 void game_size(game_params *params, int *x, int *y)
 430 {
 431     *x = TILE_SIZE * params->w + 2 * BORDER;
 432     *y = TILE_SIZE * params->h + 2 * BORDER;
 433 }
 434
 435 float *game_colours(frontend *fe, game_state *state, int *ncolours)
 436 {
 437     float *ret = snewn(3 * NCOLOURS, float);
 438     int i;
 439     float max;
 440
 441     frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
 442
 443     /*
 444      * Drop the background colour so that the highlight is
 445      * noticeably brighter than it while still being under 1.
 446      */
 447     max = ret[COL_BACKGROUND*3];
 448     for (i = 1; i < 3; i++)
 449         if (ret[COL_BACKGROUND*3+i] > max)
 450             max = ret[COL_BACKGROUND*3+i];
 451     if (max * 1.2F > 1.0F) {
 452         for (i = 0; i < 3; i++)
 453             ret[COL_BACKGROUND*3+i] /= (max * 1.2F);
 454     }
 455
 456     for (i = 0; i < 3; i++) {
 457         ret[COL_HIGHLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 1.2F;
 458         ret[COL_LOWLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 0.8F;
 459         ret[COL_TEXT * 3 + i] = 0.0;
 460     }
 461
 462     *ncolours = NCOLOURS;
 463     return ret;
 464 }
 465
 466 game_drawstate *game_new_drawstate(game_state *state)
 467 {
 468     struct game_drawstate *ds = snew(struct game_drawstate);
 469     int i;
 470
 471     ds->started = FALSE;
 472     ds->w = state->w;
 473     ds->h = state->h;
 474     ds->bgcolour = COL_BACKGROUND;
 475     ds->tiles = snewn(ds->w*ds->h, int);
 476     for (i = 0; i < ds->w*ds->h; i++)
 477         ds->tiles[i] = -1;
 478
 479     return ds;
 480 }
 481
 482 void game_free_drawstate(game_drawstate *ds)
 483 {
 484     sfree(ds->tiles);
 485     sfree(ds);
 486 }
 487
 488 static void draw_tile(frontend *fe, game_state *state, int x, int y,
 489                       int tile, int flash_colour)
 490 {
 491     if (tile == 0) {
 492         draw_rect(fe, x, y, TILE_SIZE, TILE_SIZE,
 493                   flash_colour);
 494     } else {
 495         int coords[6];
 496         char str[40];
 497
 498         coords[0] = x + TILE_SIZE - 1;
 499         coords[1] = y + TILE_SIZE - 1;
 500         coords[2] = x + TILE_SIZE - 1;
 501         coords[3] = y;
 502         coords[4] = x;
 503         coords[5] = y + TILE_SIZE - 1;
 504         draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
 505         draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);
 506
 507         coords[0] = x;
 508         coords[1] = y;
 509         draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
 510         draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);
 511
 512         draw_rect(fe, x + HIGHLIGHT_WIDTH, y + HIGHLIGHT_WIDTH,
 513                   TILE_SIZE - 2*HIGHLIGHT_WIDTH, TILE_SIZE - 2*HIGHLIGHT_WIDTH,
 514                   flash_colour);
 515
 516         sprintf(str, "%d", tile);
 517         draw_text(fe, x + TILE_SIZE/2, y + TILE_SIZE/2,
 518                   FONT_VARIABLE, TILE_SIZE/3, ALIGN_VCENTRE | ALIGN_HCENTRE,
 519                   COL_TEXT, str);
 520     }
 521     draw_update(fe, x, y, TILE_SIZE, TILE_SIZE);
 522 }
 523
 524 static void draw_arrow(frontend *fe, int x, int y, int xdx, int xdy)
 525 {
 526     int coords[14];
 527     int ydy = -xdx, ydx = xdy;
 528
 529 #define POINT(n, xx, yy) ( \
 530     coords[2*(n)+0] = x + (xx)*xdx + (yy)*ydx, \
 531     coords[2*(n)+1] = y + (xx)*xdy + (yy)*ydy)
 532
 533     POINT(0, TILE_SIZE / 2, 3 * TILE_SIZE / 4);   /* top of arrow */
 534     POINT(1, 3 * TILE_SIZE / 4, TILE_SIZE / 2);   /* right corner */
 535     POINT(2, 5 * TILE_SIZE / 8, TILE_SIZE / 2);   /* right concave */
 536     POINT(3, 5 * TILE_SIZE / 8, TILE_SIZE / 4);   /* bottom right */
 537     POINT(4, 3 * TILE_SIZE / 8, TILE_SIZE / 4);   /* bottom left */
 538     POINT(5, 3 * TILE_SIZE / 8, TILE_SIZE / 2);   /* left concave */
 539     POINT(6,     TILE_SIZE / 4, TILE_SIZE / 2);   /* left corner */
 540
 541     draw_polygon(fe, coords, 7, TRUE, COL_LOWLIGHT);
 542     draw_polygon(fe, coords, 7, FALSE, COL_TEXT);
 543 }
 544
 545 void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate,
 546                  game_state *state, game_ui *ui,
 547                  float animtime, float flashtime)
 548 {
 549     int i, bgcolour;
 550
 551     if (flashtime > 0) {
 552         int frame = (int)(flashtime / FLASH_FRAME);
 553         bgcolour = (frame % 2 ? COL_LOWLIGHT : COL_HIGHLIGHT);
 554     } else
 555         bgcolour = COL_BACKGROUND;
 556
 557     if (!ds->started) {
 558         int coords[6];
 559
 560         draw_rect(fe, 0, 0,
 561                   TILE_SIZE * state->w + 2 * BORDER,
 562                   TILE_SIZE * state->h + 2 * BORDER, COL_BACKGROUND);
 563         draw_update(fe, 0, 0,
 564                     TILE_SIZE * state->w + 2 * BORDER,
 565                     TILE_SIZE * state->h + 2 * BORDER);
 566
 567         /*
 568          * Recessed area containing the whole puzzle.
 569          */
 570         coords[0] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
 571         coords[1] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
 572         coords[2] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
 573         coords[3] = COORD(0) - HIGHLIGHT_WIDTH;
 574         coords[4] = COORD(0) - HIGHLIGHT_WIDTH;
 575         coords[5] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
 576         draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
 577         draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);
 578
 579         coords[1] = COORD(0) - HIGHLIGHT_WIDTH;
 580         coords[0] = COORD(0) - HIGHLIGHT_WIDTH;
 581         draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
 582         draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);
 583
 584         /*
 585          * Arrows for making moves.
 586          */
 587         for (i = 0; i < state->w; i++) {
 588             draw_arrow(fe, COORD(i), COORD(0), +1, 0);
 589             draw_arrow(fe, COORD(i+1), COORD(state->h), -1, 0);
 590         }
 591         for (i = 0; i < state->h; i++) {
 592             draw_arrow(fe, COORD(state->w), COORD(i), 0, +1);
 593             draw_arrow(fe, COORD(0), COORD(i+1), 0, -1);
 594         }
 595
 596         ds->started = TRUE;
 597     }
 598
 599     /*
 600      * Now draw each tile.
 601      */
 602
 603     clip(fe, COORD(0), COORD(0), TILE_SIZE*state->w, TILE_SIZE*state->h);
 604
 605     for (i = 0; i < state->n; i++) {
 606         int t, t0;
 607         /*
 608          * Figure out what should be displayed at this
 609          * location. It's either a simple tile, or it's a
 610          * transition between two tiles (in which case we say
 611          * -1 because it must always be drawn).
 612          */
 613
 614         if (oldstate && oldstate->tiles[i] != state->tiles[i])
 615             t = -1;
 616         else
 617             t = state->tiles[i];
 618
 619         t0 = t;
 620
 621         if (ds->bgcolour != bgcolour ||   /* always redraw when flashing */
 622             ds->tiles[i] != t || ds->tiles[i] == -1 || t == -1) {
 623             int x, y, x2, y2;
 624
 625             /*
 626              * Figure out what to _actually_ draw, and where to
 627              * draw it.
 628              */
 629             if (t == -1) {
 630                 int x0, y0, x1, y1, dx, dy;
 631                 int j;
 632                 float c;
 633                 int sense;
 634
 635                 if (oldstate && state->movecount < oldstate->movecount)
 636                     sense = -oldstate->last_movement_sense;
 637                 else
 638                     sense = state->last_movement_sense;
 639
 640                 t = state->tiles[i];
 641
 642                 /*
 643                  * FIXME: must be prepared to draw a double
 644                  * tile in some situations.
 645                  */
 646
 647                 /*
 648                  * Find the coordinates of this tile in the old and
 649                  * new states.
 650                  */
 651                 x1 = COORD(X(state, i));
 652                 y1 = COORD(Y(state, i));
 653                 for (j = 0; j < oldstate->n; j++)
 654                     if (oldstate->tiles[j] == state->tiles[i])
 655                         break;
 656                 assert(j < oldstate->n);
 657                 x0 = COORD(X(state, j));
 658                 y0 = COORD(Y(state, j));
 659
 660                 dx = (x1 - x0);
 661                 if (dx != 0 &&
 662                     dx != TILE_SIZE * sense) {
 663                     dx = (dx < 0 ? dx + TILE_SIZE * state->w :
 664                           dx - TILE_SIZE * state->w);
 665                     assert(abs(dx) == TILE_SIZE);
 666                 }
 667                 dy = (y1 - y0);
 668                 if (dy != 0 &&
 669                     dy != TILE_SIZE * sense) {
 670                     dy = (dy < 0 ? dy + TILE_SIZE * state->h :
 671                           dy - TILE_SIZE * state->h);
 672                     assert(abs(dy) == TILE_SIZE);
 673                 }
 674
 675                 c = (animtime / ANIM_TIME);
 676                 if (c < 0.0F) c = 0.0F;
 677                 if (c > 1.0F) c = 1.0F;
 678
 679                 x = x0 + (int)(c * dx);
 680                 y = y0 + (int)(c * dy);
 681                 x2 = x1 - dx + (int)(c * dx);
 682                 y2 = y1 - dy + (int)(c * dy);
 683             } else {
 684                 x = COORD(X(state, i));
 685                 y = COORD(Y(state, i));
 686                 x2 = y2 = -1;
 687             }
 688
 689             draw_tile(fe, state, x, y, t, bgcolour);
 690             if (x2 != -1 || y2 != -1)
 691                 draw_tile(fe, state, x2, y2, t, bgcolour);
 692         }
 693         ds->tiles[i] = t0;
 694     }
 695
 696     unclip(fe);
 697
 698     ds->bgcolour = bgcolour;
 699
 700     /*
 701      * Update the status bar.
 702      */
 703     {
 704         char statusbuf[256];
 705
 706         /*
 707          * Don't show the new status until we're also showing the
 708          * new _state_ - after the game animation is complete.
 709          */
 710         if (oldstate)
 711             state = oldstate;
 712
 713         sprintf(statusbuf, "%sMoves: %d",
 714                 (state->completed ? "COMPLETED! " : ""),
 715                 (state->completed ? state->completed : state->movecount));
 716
 717         status_bar(fe, statusbuf);
 718     }
 719 }
 720
 721 float game_anim_length(game_state *oldstate, game_state *newstate)
 722 {
 723     return ANIM_TIME;
 724 }
 725
 726 float game_flash_length(game_state *oldstate, game_state *newstate)
 727 {
 728     if (!oldstate->completed && newstate->completed)
 729         return 2 * FLASH_FRAME;
 730     else
 731         return 0.0F;
 732 }
 733
 734 int game_wants_statusbar(void)
 735 {
 736     return TRUE;
 737 }