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 0.1F
  25 #define FLASH_FRAME 0.1F
  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)
 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 ? rand_upto(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 game_state *new_game(game_params *params, char *seed)
 261 {
 262     game_state *state = snew(game_state);
 263     int i;
 264     char *p;
 265
 266     state->w = params->w;
 267     state->h = params->h;
 268     state->n = params->w * params->h;
 269     state->tiles = snewn(state->n, int);
 270
 271     p = seed;
 272     i = 0;
 273     for (i = 0; i < state->n; i++) {
 274         assert(*p);
 275         state->tiles[i] = atoi(p);
 276         while (*p && *p != ',')
 277             p++;
 278         if (*p) p++;                   /* eat comma */
 279     }
 280     assert(!*p);
 281
 282     state->completed = state->movecount = 0;
 283     state->last_movement_sense = 0;
 284
 285     return state;
 286 }
 287
 288 game_state *dup_game(game_state *state)
 289 {
 290     game_state *ret = snew(game_state);
 291
 292     ret->w = state->w;
 293     ret->h = state->h;
 294     ret->n = state->n;
 295     ret->tiles = snewn(state->w * state->h, int);
 296     memcpy(ret->tiles, state->tiles, state->w * state->h * sizeof(int));
 297     ret->completed = state->completed;
 298     ret->movecount = state->movecount;
 299     ret->last_movement_sense = state->last_movement_sense;
 300
 301     return ret;
 302 }
 303
 304 void free_game(game_state *state)
 305 {
 306     sfree(state);
 307 }
 308
 309 game_state *make_move(game_state *from, int x, int y, int button)
 310 {
 311     int cx, cy;
 312     int dx, dy, tx, ty, n;
 313     game_state *ret;
 314
 315     if (button != LEFT_BUTTON)
 316         return NULL;
 317
 318     cx = FROMCOORD(x);
 319     cy = FROMCOORD(y);
 320     if (cx == -1 && cy >= 0 && cy < from->h)
 321         n = from->w, dx = +1, dy = 0;
 322     else if (cx == from->w && cy >= 0 && cy < from->h)
 323         n = from->w, dx = -1, dy = 0;
 324     else if (cy == -1 && cx >= 0 && cx < from->w)
 325         n = from->h, dy = +1, dx = 0;
 326     else if (cy == from->h && cx >= 0 && cx < from->w)
 327         n = from->h, dy = -1, dx = 0;
 328     else
 329         return NULL;                   /* invalid click location */
 330
 331     ret = dup_game(from);
 332
 333     do {
 334         cx += dx;
 335         cy += dy;
 336         tx = (cx + dx + from->w) % from->w;
 337         ty = (cy + dy + from->h) % from->h;
 338         ret->tiles[C(ret, cx, cy)] = from->tiles[C(from, tx, ty)];
 339     } while (--n > 0);
 340
 341     ret->movecount++;
 342
 343     ret->last_movement_sense = -(dx+dy);
 344
 345     /*
 346      * See if the game has been completed.
 347      */
 348     if (!ret->completed) {
 349         ret->completed = ret->movecount;
 350         for (n = 0; n < ret->n; n++)
 351             if (ret->tiles[n] != n+1)
 352                 ret->completed = FALSE;
 353     }
 354
 355     return ret;
 356 }
 357
 358 /* ----------------------------------------------------------------------
 359  * Drawing routines.
 360  */
 361
 362 struct game_drawstate {
 363     int started;
 364     int w, h, bgcolour;
 365     int *tiles;
 366 };
 367
 368 void game_size(game_params *params, int *x, int *y)
 369 {
 370     *x = TILE_SIZE * params->w + 2 * BORDER;
 371     *y = TILE_SIZE * params->h + 2 * BORDER;
 372 }
 373
 374 float *game_colours(frontend *fe, game_state *state, int *ncolours)
 375 {
 376     float *ret = snewn(3 * NCOLOURS, float);
 377     int i;
 378     float max;
 379
 380     frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
 381
 382     /*
 383      * Drop the background colour so that the highlight is
 384      * noticeably brighter than it while still being under 1.
 385      */
 386     max = ret[COL_BACKGROUND*3];
 387     for (i = 1; i < 3; i++)
 388         if (ret[COL_BACKGROUND*3+i] > max)
 389             max = ret[COL_BACKGROUND*3+i];
 390     if (max * 1.2F > 1.0F) {
 391         for (i = 0; i < 3; i++)
 392             ret[COL_BACKGROUND*3+i] /= (max * 1.2F);
 393     }
 394
 395     for (i = 0; i < 3; i++) {
 396         ret[COL_HIGHLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 1.2F;
 397         ret[COL_LOWLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 0.8F;
 398         ret[COL_TEXT * 3 + i] = 0.0;
 399     }
 400
 401     *ncolours = NCOLOURS;
 402     return ret;
 403 }
 404
 405 game_drawstate *game_new_drawstate(game_state *state)
 406 {
 407     struct game_drawstate *ds = snew(struct game_drawstate);
 408     int i;
 409
 410     ds->started = FALSE;
 411     ds->w = state->w;
 412     ds->h = state->h;
 413     ds->bgcolour = COL_BACKGROUND;
 414     ds->tiles = snewn(ds->w*ds->h, int);
 415     for (i = 0; i < ds->w*ds->h; i++)
 416         ds->tiles[i] = -1;
 417
 418     return ds;
 419 }
 420
 421 void game_free_drawstate(game_drawstate *ds)
 422 {
 423     sfree(ds->tiles);
 424     sfree(ds);
 425 }
 426
 427 static void draw_tile(frontend *fe, game_state *state, int x, int y,
 428                       int tile, int flash_colour)
 429 {
 430     if (tile == 0) {
 431         draw_rect(fe, x, y, TILE_SIZE, TILE_SIZE,
 432                   flash_colour);
 433     } else {
 434         int coords[6];
 435         char str[40];
 436
 437         coords[0] = x + TILE_SIZE - 1;
 438         coords[1] = y + TILE_SIZE - 1;
 439         coords[2] = x + TILE_SIZE - 1;
 440         coords[3] = y;
 441         coords[4] = x;
 442         coords[5] = y + TILE_SIZE - 1;
 443         draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
 444         draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);
 445
 446         coords[0] = x;
 447         coords[1] = y;
 448         draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
 449         draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);
 450
 451         draw_rect(fe, x + HIGHLIGHT_WIDTH, y + HIGHLIGHT_WIDTH,
 452                   TILE_SIZE - 2*HIGHLIGHT_WIDTH, TILE_SIZE - 2*HIGHLIGHT_WIDTH,
 453                   flash_colour);
 454
 455         sprintf(str, "%d", tile);
 456         draw_text(fe, x + TILE_SIZE/2, y + TILE_SIZE/2,
 457                   FONT_VARIABLE, TILE_SIZE/3, ALIGN_VCENTRE | ALIGN_HCENTRE,
 458                   COL_TEXT, str);
 459     }
 460     draw_update(fe, x, y, TILE_SIZE, TILE_SIZE);
 461 }
 462
 463 static void draw_arrow(frontend *fe, int x, int y, int xdx, int xdy)
 464 {
 465     int coords[14];
 466     int ydy = -xdx, ydx = xdy;
 467
 468 #define POINT(n, xx, yy) ( \
 469     coords[2*(n)+0] = x + (xx)*xdx + (yy)*ydx, \
 470     coords[2*(n)+1] = y + (xx)*xdy + (yy)*ydy)
 471
 472     POINT(0, TILE_SIZE / 2, 3 * TILE_SIZE / 4);   /* top of arrow */
 473     POINT(1, 3 * TILE_SIZE / 4, TILE_SIZE / 2);   /* right corner */
 474     POINT(2, 5 * TILE_SIZE / 8, TILE_SIZE / 2);   /* right concave */
 475     POINT(3, 5 * TILE_SIZE / 8, TILE_SIZE / 4);   /* bottom right */
 476     POINT(4, 3 * TILE_SIZE / 8, TILE_SIZE / 4);   /* bottom left */
 477     POINT(5, 3 * TILE_SIZE / 8, TILE_SIZE / 2);   /* left concave */
 478     POINT(6,     TILE_SIZE / 4, TILE_SIZE / 2);   /* left corner */
 479
 480     draw_polygon(fe, coords, 7, TRUE, COL_LOWLIGHT);
 481     draw_polygon(fe, coords, 7, FALSE, COL_TEXT);
 482 }
 483
 484 void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate,
 485                  game_state *state, float animtime, float flashtime)
 486 {
 487     int i, pass, bgcolour;
 488
 489     if (flashtime > 0) {
 490         int frame = (int)(flashtime / FLASH_FRAME);
 491         bgcolour = (frame % 2 ? COL_LOWLIGHT : COL_HIGHLIGHT);
 492     } else
 493         bgcolour = COL_BACKGROUND;
 494
 495     if (!ds->started) {
 496         int coords[6];
 497
 498         draw_rect(fe, 0, 0,
 499                   TILE_SIZE * state->w + 2 * BORDER,
 500                   TILE_SIZE * state->h + 2 * BORDER, COL_BACKGROUND);
 501         draw_update(fe, 0, 0,
 502                     TILE_SIZE * state->w + 2 * BORDER,
 503                     TILE_SIZE * state->h + 2 * BORDER);
 504
 505         /*
 506          * Recessed area containing the whole puzzle.
 507          */
 508         coords[0] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
 509         coords[1] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
 510         coords[2] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
 511         coords[3] = COORD(0) - HIGHLIGHT_WIDTH;
 512         coords[4] = COORD(0) - HIGHLIGHT_WIDTH;
 513         coords[5] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
 514         draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
 515         draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);
 516
 517         coords[1] = COORD(0) - HIGHLIGHT_WIDTH;
 518         coords[0] = COORD(0) - HIGHLIGHT_WIDTH;
 519         draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
 520         draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);
 521
 522         /*
 523          * Arrows for making moves.
 524          */
 525         for (i = 0; i < state->w; i++) {
 526             draw_arrow(fe, COORD(i), COORD(0), +1, 0);
 527             draw_arrow(fe, COORD(i+1), COORD(state->h), -1, 0);
 528         }
 529         for (i = 0; i < state->h; i++) {
 530             draw_arrow(fe, COORD(state->w), COORD(i), 0, +1);
 531             draw_arrow(fe, COORD(0), COORD(i+1), 0, -1);
 532         }
 533
 534         ds->started = TRUE;
 535     }
 536
 537     /*
 538      * Now draw each tile. We do this in two passes to make
 539      * animation easy.
 540      */
 541
 542     clip(fe, COORD(0), COORD(0), TILE_SIZE*state->w, TILE_SIZE*state->h);
 543
 544     for (pass = 0; pass < 2; pass++) {
 545         for (i = 0; i < state->n; i++) {
 546             int t, t0;
 547             /*
 548              * Figure out what should be displayed at this
 549              * location. It's either a simple tile, or it's a
 550              * transition between two tiles (in which case we say
 551              * -1 because it must always be drawn).
 552              */
 553
 554             if (oldstate && oldstate->tiles[i] != state->tiles[i])
 555                 t = -1;
 556             else
 557                 t = state->tiles[i];
 558
 559             t0 = t;
 560
 561             if (ds->bgcolour != bgcolour ||   /* always redraw when flashing */
 562                 ds->tiles[i] != t || ds->tiles[i] == -1 || t == -1) {
 563                 int x, y, x2, y2;
 564
 565                 /*
 566                  * Figure out what to _actually_ draw, and where to
 567                  * draw it.
 568                  */
 569                 if (t == -1) {
 570                     int x0, y0, x1, y1, dx, dy;
 571                     int j;
 572
 573                     /*
 574                      * On the first pass, just blank the tile.
 575                      */
 576                     if (pass == 0) {
 577                         x = COORD(X(state, i));
 578                         y = COORD(Y(state, i));
 579                         x2 = y2 = -1;
 580                         t = 0;
 581                     } else {
 582                         float c;
 583
 584                         t = state->tiles[i];
 585
 586                         /*
 587                          * FIXME: must be prepared to draw a double
 588                          * tile in some situations.
 589                          */
 590
 591                         /*
 592                          * Find the coordinates of this tile in the old and
 593                          * new states.
 594                          */
 595                         x1 = COORD(X(state, i));
 596                         y1 = COORD(Y(state, i));
 597                         for (j = 0; j < oldstate->n; j++)
 598                             if (oldstate->tiles[j] == state->tiles[i])
 599                                 break;
 600                         assert(j < oldstate->n);
 601                         x0 = COORD(X(state, j));
 602                         y0 = COORD(Y(state, j));
 603
 604                         dx = (x1 - x0);
 605                         if (dx != 0 &&
 606                             dx != TILE_SIZE * state->last_movement_sense) {
 607                             dx = (dx < 0 ? dx + TILE_SIZE * state->w :
 608                                   dx - TILE_SIZE * state->w);
 609                             assert(abs(dx) == TILE_SIZE);
 610                         }
 611                         dy = (y1 - y0);
 612                         if (dy != 0 &&
 613                             dy != TILE_SIZE * state->last_movement_sense) {
 614                             dy = (dy < 0 ? dy + TILE_SIZE * state->h :
 615                                   dy - TILE_SIZE * state->h);
 616                             assert(abs(dy) == TILE_SIZE);
 617                         }
 618
 619                         c = (animtime / ANIM_TIME);
 620                         if (c < 0.0F) c = 0.0F;
 621                         if (c > 1.0F) c = 1.0F;
 622
 623                         x = x0 + (int)(c * dx);
 624                         y = y0 + (int)(c * dy);
 625                         x2 = x1 - dx + (int)(c * dx);
 626                         y2 = y1 - dy + (int)(c * dy);
 627                     }
 628
 629                 } else {
 630                     if (pass == 0)
 631                         continue;
 632                     x = COORD(X(state, i));
 633                     y = COORD(Y(state, i));
 634                     x2 = y2 = -1;
 635                 }
 636
 637                 draw_tile(fe, state, x, y, t, bgcolour);
 638                 if (x2 != -1 || y2 != -1)
 639                     draw_tile(fe, state, x2, y2, t, bgcolour);
 640             }
 641             ds->tiles[i] = t0;
 642         }
 643     }
 644
 645     unclip(fe);
 646
 647     ds->bgcolour = bgcolour;
 648
 649     /*
 650      * Update the status bar.
 651      */
 652     {
 653         char statusbuf[256];
 654
 655         /*
 656          * Don't show the new status until we're also showing the
 657          * new _state_ - after the game animation is complete.
 658          */
 659         if (oldstate)
 660             state = oldstate;
 661
 662         sprintf(statusbuf, "%sMoves: %d",
 663                 (state->completed ? "COMPLETED! " : ""),
 664                 (state->completed ? state->completed : state->movecount));
 665
 666         status_bar(fe, statusbuf);
 667     }
 668 }
 669
 670 float game_anim_length(game_state *oldstate, game_state *newstate)
 671 {
 672     return ANIM_TIME;
 673 }
 674
 675 float game_flash_length(game_state *oldstate, game_state *newstate)
 676 {
 677     if (!oldstate->completed && newstate->completed)
 678         return 2 * FLASH_FRAME;
 679     else
 680         return 0.0F;
 681 }
 682
 683 int game_wants_statusbar(void)
 684 {
 685     return TRUE;
 686 }