| 1 | /* |
| 2 | * solo.c: the number-placing puzzle most popularly known as `Sudoku'. |
| 3 | * |
| 4 | * TODO: |
| 5 | * |
| 6 | * - finalise game name |
| 7 | * |
| 8 | * - can we do anything about nasty centring of text in GTK? It |
| 9 | * seems to be taking ascenders/descenders into account when |
| 10 | * centring. Ick. |
| 11 | * |
| 12 | * - implement stronger modes of reasoning in nsolve, thus |
| 13 | * enabling harder puzzles |
| 14 | * |
| 15 | * - configurable difficulty levels |
| 16 | * |
| 17 | * - vary the symmetry (rotational or none)? |
| 18 | * |
| 19 | * - try for cleverer ways of reducing the solved grid; they seem |
| 20 | * to be coming out a bit full for the most part, and in |
| 21 | * particular it's inexcusable to leave a grid with an entire |
| 22 | * block (or presumably row or column) filled! I _hope_ we can |
| 23 | * do this simply by better prioritising (somehow) the possible |
| 24 | * removals. |
| 25 | * + one simple option might be to work the other way: start |
| 26 | * with an empty grid and gradually _add_ numbers until it |
| 27 | * becomes solvable? Perhaps there might be some heuristic |
| 28 | * which enables us to pinpoint the most critical clues and |
| 29 | * thus add as few as possible. |
| 30 | * |
| 31 | * - alternative interface modes |
| 32 | * + sudoku.com's Windows program has a palette of possible |
| 33 | * entries; you select a palette entry first and then click |
| 34 | * on the square you want it to go in, thus enabling |
| 35 | * mouse-only play. Useful for PDAs! I don't think it's |
| 36 | * actually incompatible with the current highlight-then-type |
| 37 | * approach: you _either_ highlight a palette entry and then |
| 38 | * click, _or_ you highlight a square and then type. At most |
| 39 | * one thing is ever highlighted at a time, so there's no way |
| 40 | * to confuse the two. |
| 41 | * + `pencil marks' might be useful for more subtle forms of |
| 42 | * deduction, once we implement creation of puzzles that |
| 43 | * require it. |
| 44 | */ |
| 45 | |
| 46 | /* |
| 47 | * Solo puzzles need to be square overall (since each row and each |
| 48 | * column must contain one of every digit), but they need not be |
| 49 | * subdivided the same way internally. I am going to adopt a |
| 50 | * convention whereby I _always_ refer to `r' as the number of rows |
| 51 | * of _big_ divisions, and `c' as the number of columns of _big_ |
| 52 | * divisions. Thus, a 2c by 3r puzzle looks something like this: |
| 53 | * |
| 54 | * 4 5 1 | 2 6 3 |
| 55 | * 6 3 2 | 5 4 1 |
| 56 | * ------+------ (Of course, you can't subdivide it the other way |
| 57 | * 1 4 5 | 6 3 2 or you'll get clashes; observe that the 4 in the |
| 58 | * 3 2 6 | 4 1 5 top left would conflict with the 4 in the second |
| 59 | * ------+------ box down on the left-hand side.) |
| 60 | * 5 1 4 | 3 2 6 |
| 61 | * 2 6 3 | 1 5 4 |
| 62 | * |
| 63 | * The need for a strong naming convention should now be clear: |
| 64 | * each small box is two rows of digits by three columns, while the |
| 65 | * overall puzzle has three rows of small boxes by two columns. So |
| 66 | * I will (hopefully) consistently use `r' to denote the number of |
| 67 | * rows _of small boxes_ (here 3), which is also the number of |
| 68 | * columns of digits in each small box; and `c' vice versa (here |
| 69 | * 2). |
| 70 | * |
| 71 | * I'm also going to choose arbitrarily to list c first wherever |
| 72 | * possible: the above is a 2x3 puzzle, not a 3x2 one. |
| 73 | */ |
| 74 | |
| 75 | #include <stdio.h> |
| 76 | #include <stdlib.h> |
| 77 | #include <string.h> |
| 78 | #include <assert.h> |
| 79 | #include <ctype.h> |
| 80 | #include <math.h> |
| 81 | |
| 82 | #include "puzzles.h" |
| 83 | |
| 84 | /* |
| 85 | * To save space, I store digits internally as unsigned char. This |
| 86 | * imposes a hard limit of 255 on the order of the puzzle. Since |
| 87 | * even a 5x5 takes unacceptably long to generate, I don't see this |
| 88 | * as a serious limitation unless something _really_ impressive |
| 89 | * happens in computing technology; but here's a typedef anyway for |
| 90 | * general good practice. |
| 91 | */ |
| 92 | typedef unsigned char digit; |
| 93 | #define ORDER_MAX 255 |
| 94 | |
| 95 | #define TILE_SIZE 32 |
| 96 | #define BORDER 18 |
| 97 | |
| 98 | #define FLASH_TIME 0.4F |
| 99 | |
| 100 | enum { |
| 101 | COL_BACKGROUND, |
| 102 | COL_GRID, |
| 103 | COL_CLUE, |
| 104 | COL_USER, |
| 105 | COL_HIGHLIGHT, |
| 106 | NCOLOURS |
| 107 | }; |
| 108 | |
| 109 | struct game_params { |
| 110 | int c, r; |
| 111 | }; |
| 112 | |
| 113 | struct game_state { |
| 114 | int c, r; |
| 115 | digit *grid; |
| 116 | unsigned char *immutable; /* marks which digits are clues */ |
| 117 | int completed; |
| 118 | }; |
| 119 | |
| 120 | static game_params *default_params(void) |
| 121 | { |
| 122 | game_params *ret = snew(game_params); |
| 123 | |
| 124 | ret->c = ret->r = 3; |
| 125 | |
| 126 | return ret; |
| 127 | } |
| 128 | |
| 129 | static int game_fetch_preset(int i, char **name, game_params **params) |
| 130 | { |
| 131 | game_params *ret; |
| 132 | int c, r; |
| 133 | char buf[80]; |
| 134 | |
| 135 | switch (i) { |
| 136 | case 0: c = 2, r = 2; break; |
| 137 | case 1: c = 2, r = 3; break; |
| 138 | case 2: c = 3, r = 3; break; |
| 139 | case 3: c = 3, r = 4; break; |
| 140 | case 4: c = 4, r = 4; break; |
| 141 | default: return FALSE; |
| 142 | } |
| 143 | |
| 144 | sprintf(buf, "%dx%d", c, r); |
| 145 | *name = dupstr(buf); |
| 146 | *params = ret = snew(game_params); |
| 147 | ret->c = c; |
| 148 | ret->r = r; |
| 149 | /* FIXME: difficulty presets? */ |
| 150 | return TRUE; |
| 151 | } |
| 152 | |
| 153 | static void free_params(game_params *params) |
| 154 | { |
| 155 | sfree(params); |
| 156 | } |
| 157 | |
| 158 | static game_params *dup_params(game_params *params) |
| 159 | { |
| 160 | game_params *ret = snew(game_params); |
| 161 | *ret = *params; /* structure copy */ |
| 162 | return ret; |
| 163 | } |
| 164 | |
| 165 | static game_params *decode_params(char const *string) |
| 166 | { |
| 167 | game_params *ret = default_params(); |
| 168 | |
| 169 | ret->c = ret->r = atoi(string); |
| 170 | while (*string && isdigit((unsigned char)*string)) string++; |
| 171 | if (*string == 'x') { |
| 172 | string++; |
| 173 | ret->r = atoi(string); |
| 174 | while (*string && isdigit((unsigned char)*string)) string++; |
| 175 | } |
| 176 | /* FIXME: difficulty levels */ |
| 177 | |
| 178 | return ret; |
| 179 | } |
| 180 | |
| 181 | static char *encode_params(game_params *params) |
| 182 | { |
| 183 | char str[80]; |
| 184 | |
| 185 | sprintf(str, "%dx%d", params->c, params->r); |
| 186 | return dupstr(str); |
| 187 | } |
| 188 | |
| 189 | static config_item *game_configure(game_params *params) |
| 190 | { |
| 191 | config_item *ret; |
| 192 | char buf[80]; |
| 193 | |
| 194 | ret = snewn(5, config_item); |
| 195 | |
| 196 | ret[0].name = "Columns of sub-blocks"; |
| 197 | ret[0].type = C_STRING; |
| 198 | sprintf(buf, "%d", params->c); |
| 199 | ret[0].sval = dupstr(buf); |
| 200 | ret[0].ival = 0; |
| 201 | |
| 202 | ret[1].name = "Rows of sub-blocks"; |
| 203 | ret[1].type = C_STRING; |
| 204 | sprintf(buf, "%d", params->r); |
| 205 | ret[1].sval = dupstr(buf); |
| 206 | ret[1].ival = 0; |
| 207 | |
| 208 | /* |
| 209 | * FIXME: difficulty level. |
| 210 | */ |
| 211 | |
| 212 | ret[2].name = NULL; |
| 213 | ret[2].type = C_END; |
| 214 | ret[2].sval = NULL; |
| 215 | ret[2].ival = 0; |
| 216 | |
| 217 | return ret; |
| 218 | } |
| 219 | |
| 220 | static game_params *custom_params(config_item *cfg) |
| 221 | { |
| 222 | game_params *ret = snew(game_params); |
| 223 | |
| 224 | ret->c = atoi(cfg[0].sval); |
| 225 | ret->r = atoi(cfg[1].sval); |
| 226 | |
| 227 | return ret; |
| 228 | } |
| 229 | |
| 230 | static char *validate_params(game_params *params) |
| 231 | { |
| 232 | if (params->c < 2 || params->r < 2) |
| 233 | return "Both dimensions must be at least 2"; |
| 234 | if (params->c > ORDER_MAX || params->r > ORDER_MAX) |
| 235 | return "Dimensions greater than "STR(ORDER_MAX)" are not supported"; |
| 236 | return NULL; |
| 237 | } |
| 238 | |
| 239 | /* ---------------------------------------------------------------------- |
| 240 | * Full recursive Solo solver. |
| 241 | * |
| 242 | * The algorithm for this solver is shamelessly copied from a |
| 243 | * Python solver written by Andrew Wilkinson (which is GPLed, but |
| 244 | * I've reused only ideas and no code). It mostly just does the |
| 245 | * obvious recursive thing: pick an empty square, put one of the |
| 246 | * possible digits in it, recurse until all squares are filled, |
| 247 | * backtrack and change some choices if necessary. |
| 248 | * |
| 249 | * The clever bit is that every time it chooses which square to |
| 250 | * fill in next, it does so by counting the number of _possible_ |
| 251 | * numbers that can go in each square, and it prioritises so that |
| 252 | * it picks a square with the _lowest_ number of possibilities. The |
| 253 | * idea is that filling in lots of the obvious bits (particularly |
| 254 | * any squares with only one possibility) will cut down on the list |
| 255 | * of possibilities for other squares and hence reduce the enormous |
| 256 | * search space as much as possible as early as possible. |
| 257 | * |
| 258 | * In practice the algorithm appeared to work very well; run on |
| 259 | * sample problems from the Times it completed in well under a |
| 260 | * second on my G5 even when written in Python, and given an empty |
| 261 | * grid (so that in principle it would enumerate _all_ solved |
| 262 | * grids!) it found the first valid solution just as quickly. So |
| 263 | * with a bit more randomisation I see no reason not to use this as |
| 264 | * my grid generator. |
| 265 | */ |
| 266 | |
| 267 | /* |
| 268 | * Internal data structure used in solver to keep track of |
| 269 | * progress. |
| 270 | */ |
| 271 | struct rsolve_coord { int x, y, r; }; |
| 272 | struct rsolve_usage { |
| 273 | int c, r, cr; /* cr == c*r */ |
| 274 | /* grid is a copy of the input grid, modified as we go along */ |
| 275 | digit *grid; |
| 276 | /* row[y*cr+n-1] TRUE if digit n has been placed in row y */ |
| 277 | unsigned char *row; |
| 278 | /* col[x*cr+n-1] TRUE if digit n has been placed in row x */ |
| 279 | unsigned char *col; |
| 280 | /* blk[(y*c+x)*cr+n-1] TRUE if digit n has been placed in block (x,y) */ |
| 281 | unsigned char *blk; |
| 282 | /* This lists all the empty spaces remaining in the grid. */ |
| 283 | struct rsolve_coord *spaces; |
| 284 | int nspaces; |
| 285 | /* If we need randomisation in the solve, this is our random state. */ |
| 286 | random_state *rs; |
| 287 | /* Number of solutions so far found, and maximum number we care about. */ |
| 288 | int solns, maxsolns; |
| 289 | }; |
| 290 | |
| 291 | /* |
| 292 | * The real recursive step in the solving function. |
| 293 | */ |
| 294 | static void rsolve_real(struct rsolve_usage *usage, digit *grid) |
| 295 | { |
| 296 | int c = usage->c, r = usage->r, cr = usage->cr; |
| 297 | int i, j, n, sx, sy, bestm, bestr; |
| 298 | int *digits; |
| 299 | |
| 300 | /* |
| 301 | * Firstly, check for completion! If there are no spaces left |
| 302 | * in the grid, we have a solution. |
| 303 | */ |
| 304 | if (usage->nspaces == 0) { |
| 305 | if (!usage->solns) { |
| 306 | /* |
| 307 | * This is our first solution, so fill in the output grid. |
| 308 | */ |
| 309 | memcpy(grid, usage->grid, cr * cr); |
| 310 | } |
| 311 | usage->solns++; |
| 312 | return; |
| 313 | } |
| 314 | |
| 315 | /* |
| 316 | * Otherwise, there must be at least one space. Find the most |
| 317 | * constrained space, using the `r' field as a tie-breaker. |
| 318 | */ |
| 319 | bestm = cr+1; /* so that any space will beat it */ |
| 320 | bestr = 0; |
| 321 | i = sx = sy = -1; |
| 322 | for (j = 0; j < usage->nspaces; j++) { |
| 323 | int x = usage->spaces[j].x, y = usage->spaces[j].y; |
| 324 | int m; |
| 325 | |
| 326 | /* |
| 327 | * Find the number of digits that could go in this space. |
| 328 | */ |
| 329 | m = 0; |
| 330 | for (n = 0; n < cr; n++) |
| 331 | if (!usage->row[y*cr+n] && !usage->col[x*cr+n] && |
| 332 | !usage->blk[((y/c)*c+(x/r))*cr+n]) |
| 333 | m++; |
| 334 | |
| 335 | if (m < bestm || (m == bestm && usage->spaces[j].r < bestr)) { |
| 336 | bestm = m; |
| 337 | bestr = usage->spaces[j].r; |
| 338 | sx = x; |
| 339 | sy = y; |
| 340 | i = j; |
| 341 | } |
| 342 | } |
| 343 | |
| 344 | /* |
| 345 | * Swap that square into the final place in the spaces array, |
| 346 | * so that decrementing nspaces will remove it from the list. |
| 347 | */ |
| 348 | if (i != usage->nspaces-1) { |
| 349 | struct rsolve_coord t; |
| 350 | t = usage->spaces[usage->nspaces-1]; |
| 351 | usage->spaces[usage->nspaces-1] = usage->spaces[i]; |
| 352 | usage->spaces[i] = t; |
| 353 | } |
| 354 | |
| 355 | /* |
| 356 | * Now we've decided which square to start our recursion at, |
| 357 | * simply go through all possible values, shuffling them |
| 358 | * randomly first if necessary. |
| 359 | */ |
| 360 | digits = snewn(bestm, int); |
| 361 | j = 0; |
| 362 | for (n = 0; n < cr; n++) |
| 363 | if (!usage->row[sy*cr+n] && !usage->col[sx*cr+n] && |
| 364 | !usage->blk[((sy/c)*c+(sx/r))*cr+n]) { |
| 365 | digits[j++] = n+1; |
| 366 | } |
| 367 | |
| 368 | if (usage->rs) { |
| 369 | /* shuffle */ |
| 370 | for (i = j; i > 1; i--) { |
| 371 | int p = random_upto(usage->rs, i); |
| 372 | if (p != i-1) { |
| 373 | int t = digits[p]; |
| 374 | digits[p] = digits[i-1]; |
| 375 | digits[i-1] = t; |
| 376 | } |
| 377 | } |
| 378 | } |
| 379 | |
| 380 | /* And finally, go through the digit list and actually recurse. */ |
| 381 | for (i = 0; i < j; i++) { |
| 382 | n = digits[i]; |
| 383 | |
| 384 | /* Update the usage structure to reflect the placing of this digit. */ |
| 385 | usage->row[sy*cr+n-1] = usage->col[sx*cr+n-1] = |
| 386 | usage->blk[((sy/c)*c+(sx/r))*cr+n-1] = TRUE; |
| 387 | usage->grid[sy*cr+sx] = n; |
| 388 | usage->nspaces--; |
| 389 | |
| 390 | /* Call the solver recursively. */ |
| 391 | rsolve_real(usage, grid); |
| 392 | |
| 393 | /* |
| 394 | * If we have seen as many solutions as we need, terminate |
| 395 | * all processing immediately. |
| 396 | */ |
| 397 | if (usage->solns >= usage->maxsolns) |
| 398 | break; |
| 399 | |
| 400 | /* Revert the usage structure. */ |
| 401 | usage->row[sy*cr+n-1] = usage->col[sx*cr+n-1] = |
| 402 | usage->blk[((sy/c)*c+(sx/r))*cr+n-1] = FALSE; |
| 403 | usage->grid[sy*cr+sx] = 0; |
| 404 | usage->nspaces++; |
| 405 | } |
| 406 | |
| 407 | sfree(digits); |
| 408 | } |
| 409 | |
| 410 | /* |
| 411 | * Entry point to solver. You give it dimensions and a starting |
| 412 | * grid, which is simply an array of N^4 digits. In that array, 0 |
| 413 | * means an empty square, and 1..N mean a clue square. |
| 414 | * |
| 415 | * Return value is the number of solutions found; searching will |
| 416 | * stop after the provided `max'. (Thus, you can pass max==1 to |
| 417 | * indicate that you only care about finding _one_ solution, or |
| 418 | * max==2 to indicate that you want to know the difference between |
| 419 | * a unique and non-unique solution.) The input parameter `grid' is |
| 420 | * also filled in with the _first_ (or only) solution found by the |
| 421 | * solver. |
| 422 | */ |
| 423 | static int rsolve(int c, int r, digit *grid, random_state *rs, int max) |
| 424 | { |
| 425 | struct rsolve_usage *usage; |
| 426 | int x, y, cr = c*r; |
| 427 | int ret; |
| 428 | |
| 429 | /* |
| 430 | * Create an rsolve_usage structure. |
| 431 | */ |
| 432 | usage = snew(struct rsolve_usage); |
| 433 | |
| 434 | usage->c = c; |
| 435 | usage->r = r; |
| 436 | usage->cr = cr; |
| 437 | |
| 438 | usage->grid = snewn(cr * cr, digit); |
| 439 | memcpy(usage->grid, grid, cr * cr); |
| 440 | |
| 441 | usage->row = snewn(cr * cr, unsigned char); |
| 442 | usage->col = snewn(cr * cr, unsigned char); |
| 443 | usage->blk = snewn(cr * cr, unsigned char); |
| 444 | memset(usage->row, FALSE, cr * cr); |
| 445 | memset(usage->col, FALSE, cr * cr); |
| 446 | memset(usage->blk, FALSE, cr * cr); |
| 447 | |
| 448 | usage->spaces = snewn(cr * cr, struct rsolve_coord); |
| 449 | usage->nspaces = 0; |
| 450 | |
| 451 | usage->solns = 0; |
| 452 | usage->maxsolns = max; |
| 453 | |
| 454 | usage->rs = rs; |
| 455 | |
| 456 | /* |
| 457 | * Now fill it in with data from the input grid. |
| 458 | */ |
| 459 | for (y = 0; y < cr; y++) { |
| 460 | for (x = 0; x < cr; x++) { |
| 461 | int v = grid[y*cr+x]; |
| 462 | if (v == 0) { |
| 463 | usage->spaces[usage->nspaces].x = x; |
| 464 | usage->spaces[usage->nspaces].y = y; |
| 465 | if (rs) |
| 466 | usage->spaces[usage->nspaces].r = random_bits(rs, 31); |
| 467 | else |
| 468 | usage->spaces[usage->nspaces].r = usage->nspaces; |
| 469 | usage->nspaces++; |
| 470 | } else { |
| 471 | usage->row[y*cr+v-1] = TRUE; |
| 472 | usage->col[x*cr+v-1] = TRUE; |
| 473 | usage->blk[((y/c)*c+(x/r))*cr+v-1] = TRUE; |
| 474 | } |
| 475 | } |
| 476 | } |
| 477 | |
| 478 | /* |
| 479 | * Run the real recursive solving function. |
| 480 | */ |
| 481 | rsolve_real(usage, grid); |
| 482 | ret = usage->solns; |
| 483 | |
| 484 | /* |
| 485 | * Clean up the usage structure now we have our answer. |
| 486 | */ |
| 487 | sfree(usage->spaces); |
| 488 | sfree(usage->blk); |
| 489 | sfree(usage->col); |
| 490 | sfree(usage->row); |
| 491 | sfree(usage->grid); |
| 492 | sfree(usage); |
| 493 | |
| 494 | /* |
| 495 | * And return. |
| 496 | */ |
| 497 | return ret; |
| 498 | } |
| 499 | |
| 500 | /* ---------------------------------------------------------------------- |
| 501 | * End of recursive solver code. |
| 502 | */ |
| 503 | |
| 504 | /* ---------------------------------------------------------------------- |
| 505 | * Less capable non-recursive solver. This one is used to check |
| 506 | * solubility of a grid as we gradually remove numbers from it: by |
| 507 | * verifying a grid using this solver we can ensure it isn't _too_ |
| 508 | * hard (e.g. does not actually require guessing and backtracking). |
| 509 | * |
| 510 | * It supports a variety of specific modes of reasoning. By |
| 511 | * enabling or disabling subsets of these modes we can arrange a |
| 512 | * range of difficulty levels. |
| 513 | */ |
| 514 | |
| 515 | /* |
| 516 | * Modes of reasoning currently supported: |
| 517 | * |
| 518 | * - Positional elimination: a number must go in a particular |
| 519 | * square because all the other empty squares in a given |
| 520 | * row/col/blk are ruled out. |
| 521 | * |
| 522 | * - Numeric elimination: a square must have a particular number |
| 523 | * in because all the other numbers that could go in it are |
| 524 | * ruled out. |
| 525 | * |
| 526 | * More advanced modes of reasoning I'd like to support in future: |
| 527 | * |
| 528 | * - Intersectional elimination: given two domains which overlap |
| 529 | * (hence one must be a block, and the other can be a row or |
| 530 | * col), if the possible locations for a particular number in |
| 531 | * one of the domains can be narrowed down to the overlap, then |
| 532 | * that number can be ruled out everywhere but the overlap in |
| 533 | * the other domain too. |
| 534 | * |
| 535 | * - Setwise numeric elimination: if there is a subset of the |
| 536 | * empty squares within a domain such that the union of the |
| 537 | * possible numbers in that subset has the same size as the |
| 538 | * subset itself, then those numbers can be ruled out everywhere |
| 539 | * else in the domain. (For example, if there are five empty |
| 540 | * squares and the possible numbers in each are 12, 23, 13, 134 |
| 541 | * and 1345, then the first three empty squares form such a |
| 542 | * subset: the numbers 1, 2 and 3 _must_ be in those three |
| 543 | * squares in some permutation, and hence we can deduce none of |
| 544 | * them can be in the fourth or fifth squares.) |
| 545 | */ |
| 546 | |
| 547 | struct nsolve_usage { |
| 548 | int c, r, cr; |
| 549 | /* |
| 550 | * We set up a cubic array, indexed by x, y and digit; each |
| 551 | * element of this array is TRUE or FALSE according to whether |
| 552 | * or not that digit _could_ in principle go in that position. |
| 553 | * |
| 554 | * The way to index this array is cube[(x*cr+y)*cr+n-1]. |
| 555 | */ |
| 556 | unsigned char *cube; |
| 557 | /* |
| 558 | * This is the grid in which we write down our final |
| 559 | * deductions. |
| 560 | */ |
| 561 | digit *grid; |
| 562 | /* |
| 563 | * Now we keep track, at a slightly higher level, of what we |
| 564 | * have yet to work out, to prevent doing the same deduction |
| 565 | * many times. |
| 566 | */ |
| 567 | /* row[y*cr+n-1] TRUE if digit n has been placed in row y */ |
| 568 | unsigned char *row; |
| 569 | /* col[x*cr+n-1] TRUE if digit n has been placed in row x */ |
| 570 | unsigned char *col; |
| 571 | /* blk[(y*c+x)*cr+n-1] TRUE if digit n has been placed in block (x,y) */ |
| 572 | unsigned char *blk; |
| 573 | }; |
| 574 | #define cube(x,y,n) (usage->cube[((x)*usage->cr+(y))*usage->cr+(n)-1]) |
| 575 | |
| 576 | /* |
| 577 | * Function called when we are certain that a particular square has |
| 578 | * a particular number in it. |
| 579 | */ |
| 580 | static void nsolve_place(struct nsolve_usage *usage, int x, int y, int n) |
| 581 | { |
| 582 | int c = usage->c, r = usage->r, cr = usage->cr; |
| 583 | int i, j, bx, by; |
| 584 | |
| 585 | assert(cube(x,y,n)); |
| 586 | |
| 587 | /* |
| 588 | * Rule out all other numbers in this square. |
| 589 | */ |
| 590 | for (i = 1; i <= cr; i++) |
| 591 | if (i != n) |
| 592 | cube(x,y,i) = FALSE; |
| 593 | |
| 594 | /* |
| 595 | * Rule out this number in all other positions in the row. |
| 596 | */ |
| 597 | for (i = 0; i < cr; i++) |
| 598 | if (i != y) |
| 599 | cube(x,i,n) = FALSE; |
| 600 | |
| 601 | /* |
| 602 | * Rule out this number in all other positions in the column. |
| 603 | */ |
| 604 | for (i = 0; i < cr; i++) |
| 605 | if (i != x) |
| 606 | cube(i,y,n) = FALSE; |
| 607 | |
| 608 | /* |
| 609 | * Rule out this number in all other positions in the block. |
| 610 | */ |
| 611 | bx = (x/r)*r; |
| 612 | by = (y/c)*c; |
| 613 | for (i = 0; i < r; i++) |
| 614 | for (j = 0; j < c; j++) |
| 615 | if (bx+i != x || by+j != y) |
| 616 | cube(bx+i,by+j,n) = FALSE; |
| 617 | |
| 618 | /* |
| 619 | * Enter the number in the result grid. |
| 620 | */ |
| 621 | usage->grid[y*cr+x] = n; |
| 622 | |
| 623 | /* |
| 624 | * Cross out this number from the list of numbers left to place |
| 625 | * in its row, its column and its block. |
| 626 | */ |
| 627 | usage->row[y*cr+n-1] = usage->col[x*cr+n-1] = |
| 628 | usage->blk[((y/c)*c+(x/r))*cr+n-1] = TRUE; |
| 629 | } |
| 630 | |
| 631 | static int nsolve_blk_pos_elim(struct nsolve_usage *usage, |
| 632 | int x, int y, int n) |
| 633 | { |
| 634 | int c = usage->c, r = usage->r; |
| 635 | int i, j, fx, fy, m; |
| 636 | |
| 637 | x *= r; |
| 638 | y *= c; |
| 639 | |
| 640 | /* |
| 641 | * Count the possible positions within this block where this |
| 642 | * number could appear. |
| 643 | */ |
| 644 | m = 0; |
| 645 | fx = fy = -1; |
| 646 | for (i = 0; i < r; i++) |
| 647 | for (j = 0; j < c; j++) |
| 648 | if (cube(x+i,y+j,n)) { |
| 649 | fx = x+i; |
| 650 | fy = y+j; |
| 651 | m++; |
| 652 | } |
| 653 | |
| 654 | if (m == 1) { |
| 655 | assert(fx >= 0 && fy >= 0); |
| 656 | nsolve_place(usage, fx, fy, n); |
| 657 | return TRUE; |
| 658 | } |
| 659 | |
| 660 | return FALSE; |
| 661 | } |
| 662 | |
| 663 | static int nsolve_row_pos_elim(struct nsolve_usage *usage, |
| 664 | int y, int n) |
| 665 | { |
| 666 | int cr = usage->cr; |
| 667 | int x, fx, m; |
| 668 | |
| 669 | /* |
| 670 | * Count the possible positions within this row where this |
| 671 | * number could appear. |
| 672 | */ |
| 673 | m = 0; |
| 674 | fx = -1; |
| 675 | for (x = 0; x < cr; x++) |
| 676 | if (cube(x,y,n)) { |
| 677 | fx = x; |
| 678 | m++; |
| 679 | } |
| 680 | |
| 681 | if (m == 1) { |
| 682 | assert(fx >= 0); |
| 683 | nsolve_place(usage, fx, y, n); |
| 684 | return TRUE; |
| 685 | } |
| 686 | |
| 687 | return FALSE; |
| 688 | } |
| 689 | |
| 690 | static int nsolve_col_pos_elim(struct nsolve_usage *usage, |
| 691 | int x, int n) |
| 692 | { |
| 693 | int cr = usage->cr; |
| 694 | int y, fy, m; |
| 695 | |
| 696 | /* |
| 697 | * Count the possible positions within this column where this |
| 698 | * number could appear. |
| 699 | */ |
| 700 | m = 0; |
| 701 | fy = -1; |
| 702 | for (y = 0; y < cr; y++) |
| 703 | if (cube(x,y,n)) { |
| 704 | fy = y; |
| 705 | m++; |
| 706 | } |
| 707 | |
| 708 | if (m == 1) { |
| 709 | assert(fy >= 0); |
| 710 | nsolve_place(usage, x, fy, n); |
| 711 | return TRUE; |
| 712 | } |
| 713 | |
| 714 | return FALSE; |
| 715 | } |
| 716 | |
| 717 | static int nsolve_num_elim(struct nsolve_usage *usage, |
| 718 | int x, int y) |
| 719 | { |
| 720 | int cr = usage->cr; |
| 721 | int n, fn, m; |
| 722 | |
| 723 | /* |
| 724 | * Count the possible numbers that could appear in this square. |
| 725 | */ |
| 726 | m = 0; |
| 727 | fn = -1; |
| 728 | for (n = 1; n <= cr; n++) |
| 729 | if (cube(x,y,n)) { |
| 730 | fn = n; |
| 731 | m++; |
| 732 | } |
| 733 | |
| 734 | if (m == 1) { |
| 735 | assert(fn > 0); |
| 736 | nsolve_place(usage, x, y, fn); |
| 737 | return TRUE; |
| 738 | } |
| 739 | |
| 740 | return FALSE; |
| 741 | } |
| 742 | |
| 743 | static int nsolve(int c, int r, digit *grid) |
| 744 | { |
| 745 | struct nsolve_usage *usage; |
| 746 | int cr = c*r; |
| 747 | int x, y, n; |
| 748 | |
| 749 | /* |
| 750 | * Set up a usage structure as a clean slate (everything |
| 751 | * possible). |
| 752 | */ |
| 753 | usage = snew(struct nsolve_usage); |
| 754 | usage->c = c; |
| 755 | usage->r = r; |
| 756 | usage->cr = cr; |
| 757 | usage->cube = snewn(cr*cr*cr, unsigned char); |
| 758 | usage->grid = grid; /* write straight back to the input */ |
| 759 | memset(usage->cube, TRUE, cr*cr*cr); |
| 760 | |
| 761 | usage->row = snewn(cr * cr, unsigned char); |
| 762 | usage->col = snewn(cr * cr, unsigned char); |
| 763 | usage->blk = snewn(cr * cr, unsigned char); |
| 764 | memset(usage->row, FALSE, cr * cr); |
| 765 | memset(usage->col, FALSE, cr * cr); |
| 766 | memset(usage->blk, FALSE, cr * cr); |
| 767 | |
| 768 | /* |
| 769 | * Place all the clue numbers we are given. |
| 770 | */ |
| 771 | for (x = 0; x < cr; x++) |
| 772 | for (y = 0; y < cr; y++) |
| 773 | if (grid[y*cr+x]) |
| 774 | nsolve_place(usage, x, y, grid[y*cr+x]); |
| 775 | |
| 776 | /* |
| 777 | * Now loop over the grid repeatedly trying all permitted modes |
| 778 | * of reasoning. The loop terminates if we complete an |
| 779 | * iteration without making any progress; we then return |
| 780 | * failure or success depending on whether the grid is full or |
| 781 | * not. |
| 782 | */ |
| 783 | while (1) { |
| 784 | /* |
| 785 | * Blockwise positional elimination. |
| 786 | */ |
| 787 | for (x = 0; x < c; x++) |
| 788 | for (y = 0; y < r; y++) |
| 789 | for (n = 1; n <= cr; n++) |
| 790 | if (!usage->blk[((y/c)*c+(x/r))*cr+n-1] && |
| 791 | nsolve_blk_pos_elim(usage, x, y, n)) |
| 792 | continue; |
| 793 | |
| 794 | /* |
| 795 | * Row-wise positional elimination. |
| 796 | */ |
| 797 | for (y = 0; y < cr; y++) |
| 798 | for (n = 1; n <= cr; n++) |
| 799 | if (!usage->row[y*cr+n-1] && |
| 800 | nsolve_row_pos_elim(usage, y, n)) |
| 801 | continue; |
| 802 | /* |
| 803 | * Column-wise positional elimination. |
| 804 | */ |
| 805 | for (x = 0; x < cr; x++) |
| 806 | for (n = 1; n <= cr; n++) |
| 807 | if (!usage->col[x*cr+n-1] && |
| 808 | nsolve_col_pos_elim(usage, x, n)) |
| 809 | continue; |
| 810 | |
| 811 | /* |
| 812 | * Numeric elimination. |
| 813 | */ |
| 814 | for (x = 0; x < cr; x++) |
| 815 | for (y = 0; y < cr; y++) |
| 816 | if (!usage->grid[y*cr+x] && |
| 817 | nsolve_num_elim(usage, x, y)) |
| 818 | continue; |
| 819 | |
| 820 | /* |
| 821 | * If we reach here, we have made no deductions in this |
| 822 | * iteration, so the algorithm terminates. |
| 823 | */ |
| 824 | break; |
| 825 | } |
| 826 | |
| 827 | sfree(usage->cube); |
| 828 | sfree(usage->row); |
| 829 | sfree(usage->col); |
| 830 | sfree(usage->blk); |
| 831 | sfree(usage); |
| 832 | |
| 833 | for (x = 0; x < cr; x++) |
| 834 | for (y = 0; y < cr; y++) |
| 835 | if (!grid[y*cr+x]) |
| 836 | return FALSE; |
| 837 | return TRUE; |
| 838 | } |
| 839 | |
| 840 | /* ---------------------------------------------------------------------- |
| 841 | * End of non-recursive solver code. |
| 842 | */ |
| 843 | |
| 844 | /* |
| 845 | * Check whether a grid contains a valid complete puzzle. |
| 846 | */ |
| 847 | static int check_valid(int c, int r, digit *grid) |
| 848 | { |
| 849 | int cr = c*r; |
| 850 | unsigned char *used; |
| 851 | int x, y, n; |
| 852 | |
| 853 | used = snewn(cr, unsigned char); |
| 854 | |
| 855 | /* |
| 856 | * Check that each row contains precisely one of everything. |
| 857 | */ |
| 858 | for (y = 0; y < cr; y++) { |
| 859 | memset(used, FALSE, cr); |
| 860 | for (x = 0; x < cr; x++) |
| 861 | if (grid[y*cr+x] > 0 && grid[y*cr+x] <= cr) |
| 862 | used[grid[y*cr+x]-1] = TRUE; |
| 863 | for (n = 0; n < cr; n++) |
| 864 | if (!used[n]) { |
| 865 | sfree(used); |
| 866 | return FALSE; |
| 867 | } |
| 868 | } |
| 869 | |
| 870 | /* |
| 871 | * Check that each column contains precisely one of everything. |
| 872 | */ |
| 873 | for (x = 0; x < cr; x++) { |
| 874 | memset(used, FALSE, cr); |
| 875 | for (y = 0; y < cr; y++) |
| 876 | if (grid[y*cr+x] > 0 && grid[y*cr+x] <= cr) |
| 877 | used[grid[y*cr+x]-1] = TRUE; |
| 878 | for (n = 0; n < cr; n++) |
| 879 | if (!used[n]) { |
| 880 | sfree(used); |
| 881 | return FALSE; |
| 882 | } |
| 883 | } |
| 884 | |
| 885 | /* |
| 886 | * Check that each block contains precisely one of everything. |
| 887 | */ |
| 888 | for (x = 0; x < cr; x += r) { |
| 889 | for (y = 0; y < cr; y += c) { |
| 890 | int xx, yy; |
| 891 | memset(used, FALSE, cr); |
| 892 | for (xx = x; xx < x+r; xx++) |
| 893 | for (yy = 0; yy < y+c; yy++) |
| 894 | if (grid[yy*cr+xx] > 0 && grid[yy*cr+xx] <= cr) |
| 895 | used[grid[yy*cr+xx]-1] = TRUE; |
| 896 | for (n = 0; n < cr; n++) |
| 897 | if (!used[n]) { |
| 898 | sfree(used); |
| 899 | return FALSE; |
| 900 | } |
| 901 | } |
| 902 | } |
| 903 | |
| 904 | sfree(used); |
| 905 | return TRUE; |
| 906 | } |
| 907 | |
| 908 | static char *new_game_seed(game_params *params, random_state *rs) |
| 909 | { |
| 910 | int c = params->c, r = params->r, cr = c*r; |
| 911 | int area = cr*cr; |
| 912 | digit *grid, *grid2; |
| 913 | struct xy { int x, y; } *locs; |
| 914 | int nlocs; |
| 915 | int ret; |
| 916 | char *seed; |
| 917 | |
| 918 | /* |
| 919 | * Start the recursive solver with an empty grid to generate a |
| 920 | * random solved state. |
| 921 | */ |
| 922 | grid = snewn(area, digit); |
| 923 | memset(grid, 0, area); |
| 924 | ret = rsolve(c, r, grid, rs, 1); |
| 925 | assert(ret == 1); |
| 926 | assert(check_valid(c, r, grid)); |
| 927 | |
| 928 | #ifdef DEBUG |
| 929 | memcpy(grid, |
| 930 | "\x0\x1\x0\x0\x6\x0\x0\x0\x0" |
| 931 | "\x5\x0\x0\x7\x0\x4\x0\x2\x0" |
| 932 | "\x0\x0\x6\x1\x0\x0\x0\x0\x0" |
| 933 | "\x8\x9\x7\x0\x0\x0\x0\x0\x0" |
| 934 | "\x0\x0\x3\x0\x4\x0\x9\x0\x0" |
| 935 | "\x0\x0\x0\x0\x0\x0\x8\x7\x6" |
| 936 | "\x0\x0\x0\x0\x0\x9\x1\x0\x0" |
| 937 | "\x0\x3\x0\x6\x0\x5\x0\x0\x7" |
| 938 | "\x0\x0\x0\x0\x8\x0\x0\x5\x0" |
| 939 | , area); |
| 940 | |
| 941 | { |
| 942 | int y, x; |
| 943 | for (y = 0; y < cr; y++) { |
| 944 | for (x = 0; x < cr; x++) { |
| 945 | printf("%2.0d", grid[y*cr+x]); |
| 946 | } |
| 947 | printf("\n"); |
| 948 | } |
| 949 | printf("\n"); |
| 950 | } |
| 951 | |
| 952 | nsolve(c, r, grid); |
| 953 | |
| 954 | { |
| 955 | int y, x; |
| 956 | for (y = 0; y < cr; y++) { |
| 957 | for (x = 0; x < cr; x++) { |
| 958 | printf("%2.0d", grid[y*cr+x]); |
| 959 | } |
| 960 | printf("\n"); |
| 961 | } |
| 962 | printf("\n"); |
| 963 | } |
| 964 | #endif |
| 965 | |
| 966 | /* |
| 967 | * Now we have a solved grid, start removing things from it |
| 968 | * while preserving solubility. |
| 969 | */ |
| 970 | locs = snewn((cr+1)/2 * (cr+1)/2, struct xy); |
| 971 | grid2 = snewn(area, digit); |
| 972 | while (1) { |
| 973 | int x, y, i; |
| 974 | |
| 975 | /* |
| 976 | * Iterate over the top left corner of the grid and |
| 977 | * enumerate all the filled squares we could empty. |
| 978 | */ |
| 979 | nlocs = 0; |
| 980 | |
| 981 | for (x = 0; 2*x < cr; x++) |
| 982 | for (y = 0; 2*y < cr; y++) |
| 983 | if (grid[y*cr+x]) { |
| 984 | locs[nlocs].x = x; |
| 985 | locs[nlocs].y = y; |
| 986 | nlocs++; |
| 987 | } |
| 988 | |
| 989 | /* |
| 990 | * Now shuffle that list. |
| 991 | */ |
| 992 | for (i = nlocs; i > 1; i--) { |
| 993 | int p = random_upto(rs, i); |
| 994 | if (p != i-1) { |
| 995 | struct xy t = locs[p]; |
| 996 | locs[p] = locs[i-1]; |
| 997 | locs[i-1] = t; |
| 998 | } |
| 999 | } |
| 1000 | |
| 1001 | /* |
| 1002 | * Now loop over the shuffled list and, for each element, |
| 1003 | * see whether removing that element (and its reflections) |
| 1004 | * from the grid will still leave the grid soluble by |
| 1005 | * nsolve. |
| 1006 | */ |
| 1007 | for (i = 0; i < nlocs; i++) { |
| 1008 | x = locs[i].x; |
| 1009 | y = locs[i].y; |
| 1010 | |
| 1011 | memcpy(grid2, grid, area); |
| 1012 | grid2[y*cr+x] = 0; |
| 1013 | grid2[y*cr+cr-1-x] = 0; |
| 1014 | grid2[(cr-1-y)*cr+x] = 0; |
| 1015 | grid2[(cr-1-y)*cr+cr-1-x] = 0; |
| 1016 | |
| 1017 | if (nsolve(c, r, grid2)) { |
| 1018 | grid[y*cr+x] = 0; |
| 1019 | grid[y*cr+cr-1-x] = 0; |
| 1020 | grid[(cr-1-y)*cr+x] = 0; |
| 1021 | grid[(cr-1-y)*cr+cr-1-x] = 0; |
| 1022 | break; |
| 1023 | } |
| 1024 | } |
| 1025 | |
| 1026 | if (i == nlocs) { |
| 1027 | /* |
| 1028 | * There was nothing we could remove without destroying |
| 1029 | * solvability. |
| 1030 | */ |
| 1031 | break; |
| 1032 | } |
| 1033 | } |
| 1034 | sfree(grid2); |
| 1035 | sfree(locs); |
| 1036 | |
| 1037 | #ifdef DEBUG |
| 1038 | { |
| 1039 | int y, x; |
| 1040 | for (y = 0; y < cr; y++) { |
| 1041 | for (x = 0; x < cr; x++) { |
| 1042 | printf("%2.0d", grid[y*cr+x]); |
| 1043 | } |
| 1044 | printf("\n"); |
| 1045 | } |
| 1046 | printf("\n"); |
| 1047 | } |
| 1048 | #endif |
| 1049 | |
| 1050 | /* |
| 1051 | * Now we have the grid as it will be presented to the user. |
| 1052 | * Encode it in a game seed. |
| 1053 | */ |
| 1054 | { |
| 1055 | char *p; |
| 1056 | int run, i; |
| 1057 | |
| 1058 | seed = snewn(5 * area, char); |
| 1059 | p = seed; |
| 1060 | run = 0; |
| 1061 | for (i = 0; i <= area; i++) { |
| 1062 | int n = (i < area ? grid[i] : -1); |
| 1063 | |
| 1064 | if (!n) |
| 1065 | run++; |
| 1066 | else { |
| 1067 | if (run) { |
| 1068 | while (run > 0) { |
| 1069 | int c = 'a' - 1 + run; |
| 1070 | if (run > 26) |
| 1071 | c = 'z'; |
| 1072 | *p++ = c; |
| 1073 | run -= c - ('a' - 1); |
| 1074 | } |
| 1075 | } else { |
| 1076 | /* |
| 1077 | * If there's a number in the very top left or |
| 1078 | * bottom right, there's no point putting an |
| 1079 | * unnecessary _ before or after it. |
| 1080 | */ |
| 1081 | if (p > seed && n > 0) |
| 1082 | *p++ = '_'; |
| 1083 | } |
| 1084 | if (n > 0) |
| 1085 | p += sprintf(p, "%d", n); |
| 1086 | run = 0; |
| 1087 | } |
| 1088 | } |
| 1089 | assert(p - seed < 5 * area); |
| 1090 | *p++ = '\0'; |
| 1091 | seed = sresize(seed, p - seed, char); |
| 1092 | } |
| 1093 | |
| 1094 | sfree(grid); |
| 1095 | |
| 1096 | return seed; |
| 1097 | } |
| 1098 | |
| 1099 | static char *validate_seed(game_params *params, char *seed) |
| 1100 | { |
| 1101 | int area = params->r * params->r * params->c * params->c; |
| 1102 | int squares = 0; |
| 1103 | |
| 1104 | while (*seed) { |
| 1105 | int n = *seed++; |
| 1106 | if (n >= 'a' && n <= 'z') { |
| 1107 | squares += n - 'a' + 1; |
| 1108 | } else if (n == '_') { |
| 1109 | /* do nothing */; |
| 1110 | } else if (n > '0' && n <= '9') { |
| 1111 | squares++; |
| 1112 | while (*seed >= '0' && *seed <= '9') |
| 1113 | seed++; |
| 1114 | } else |
| 1115 | return "Invalid character in game specification"; |
| 1116 | } |
| 1117 | |
| 1118 | if (squares < area) |
| 1119 | return "Not enough data to fill grid"; |
| 1120 | |
| 1121 | if (squares > area) |
| 1122 | return "Too much data to fit in grid"; |
| 1123 | |
| 1124 | return NULL; |
| 1125 | } |
| 1126 | |
| 1127 | static game_state *new_game(game_params *params, char *seed) |
| 1128 | { |
| 1129 | game_state *state = snew(game_state); |
| 1130 | int c = params->c, r = params->r, cr = c*r, area = cr * cr; |
| 1131 | int i; |
| 1132 | |
| 1133 | state->c = params->c; |
| 1134 | state->r = params->r; |
| 1135 | |
| 1136 | state->grid = snewn(area, digit); |
| 1137 | state->immutable = snewn(area, unsigned char); |
| 1138 | memset(state->immutable, FALSE, area); |
| 1139 | |
| 1140 | state->completed = FALSE; |
| 1141 | |
| 1142 | i = 0; |
| 1143 | while (*seed) { |
| 1144 | int n = *seed++; |
| 1145 | if (n >= 'a' && n <= 'z') { |
| 1146 | int run = n - 'a' + 1; |
| 1147 | assert(i + run <= area); |
| 1148 | while (run-- > 0) |
| 1149 | state->grid[i++] = 0; |
| 1150 | } else if (n == '_') { |
| 1151 | /* do nothing */; |
| 1152 | } else if (n > '0' && n <= '9') { |
| 1153 | assert(i < area); |
| 1154 | state->immutable[i] = TRUE; |
| 1155 | state->grid[i++] = atoi(seed-1); |
| 1156 | while (*seed >= '0' && *seed <= '9') |
| 1157 | seed++; |
| 1158 | } else { |
| 1159 | assert(!"We can't get here"); |
| 1160 | } |
| 1161 | } |
| 1162 | assert(i == area); |
| 1163 | |
| 1164 | return state; |
| 1165 | } |
| 1166 | |
| 1167 | static game_state *dup_game(game_state *state) |
| 1168 | { |
| 1169 | game_state *ret = snew(game_state); |
| 1170 | int c = state->c, r = state->r, cr = c*r, area = cr * cr; |
| 1171 | |
| 1172 | ret->c = state->c; |
| 1173 | ret->r = state->r; |
| 1174 | |
| 1175 | ret->grid = snewn(area, digit); |
| 1176 | memcpy(ret->grid, state->grid, area); |
| 1177 | |
| 1178 | ret->immutable = snewn(area, unsigned char); |
| 1179 | memcpy(ret->immutable, state->immutable, area); |
| 1180 | |
| 1181 | ret->completed = state->completed; |
| 1182 | |
| 1183 | return ret; |
| 1184 | } |
| 1185 | |
| 1186 | static void free_game(game_state *state) |
| 1187 | { |
| 1188 | sfree(state->immutable); |
| 1189 | sfree(state->grid); |
| 1190 | sfree(state); |
| 1191 | } |
| 1192 | |
| 1193 | struct game_ui { |
| 1194 | /* |
| 1195 | * These are the coordinates of the currently highlighted |
| 1196 | * square on the grid, or -1,-1 if there isn't one. When there |
| 1197 | * is, pressing a valid number or letter key or Space will |
| 1198 | * enter that number or letter in the grid. |
| 1199 | */ |
| 1200 | int hx, hy; |
| 1201 | }; |
| 1202 | |
| 1203 | static game_ui *new_ui(game_state *state) |
| 1204 | { |
| 1205 | game_ui *ui = snew(game_ui); |
| 1206 | |
| 1207 | ui->hx = ui->hy = -1; |
| 1208 | |
| 1209 | return ui; |
| 1210 | } |
| 1211 | |
| 1212 | static void free_ui(game_ui *ui) |
| 1213 | { |
| 1214 | sfree(ui); |
| 1215 | } |
| 1216 | |
| 1217 | static game_state *make_move(game_state *from, game_ui *ui, int x, int y, |
| 1218 | int button) |
| 1219 | { |
| 1220 | int c = from->c, r = from->r, cr = c*r; |
| 1221 | int tx, ty; |
| 1222 | game_state *ret; |
| 1223 | |
| 1224 | tx = (x - BORDER) / TILE_SIZE; |
| 1225 | ty = (y - BORDER) / TILE_SIZE; |
| 1226 | |
| 1227 | if (tx >= 0 && tx < cr && ty >= 0 && ty < cr && button == LEFT_BUTTON) { |
| 1228 | if (tx == ui->hx && ty == ui->hy) { |
| 1229 | ui->hx = ui->hy = -1; |
| 1230 | } else { |
| 1231 | ui->hx = tx; |
| 1232 | ui->hy = ty; |
| 1233 | } |
| 1234 | return from; /* UI activity occurred */ |
| 1235 | } |
| 1236 | |
| 1237 | if (ui->hx != -1 && ui->hy != -1 && |
| 1238 | ((button >= '1' && button <= '9' && button - '0' <= cr) || |
| 1239 | (button >= 'a' && button <= 'z' && button - 'a' + 10 <= cr) || |
| 1240 | (button >= 'A' && button <= 'Z' && button - 'A' + 10 <= cr) || |
| 1241 | button == ' ')) { |
| 1242 | int n = button - '0'; |
| 1243 | if (button >= 'A' && button <= 'Z') |
| 1244 | n = button - 'A' + 10; |
| 1245 | if (button >= 'a' && button <= 'z') |
| 1246 | n = button - 'a' + 10; |
| 1247 | if (button == ' ') |
| 1248 | n = 0; |
| 1249 | |
| 1250 | if (from->immutable[ui->hy*cr+ui->hx]) |
| 1251 | return NULL; /* can't overwrite this square */ |
| 1252 | |
| 1253 | ret = dup_game(from); |
| 1254 | ret->grid[ui->hy*cr+ui->hx] = n; |
| 1255 | ui->hx = ui->hy = -1; |
| 1256 | |
| 1257 | /* |
| 1258 | * We've made a real change to the grid. Check to see |
| 1259 | * if the game has been completed. |
| 1260 | */ |
| 1261 | if (!ret->completed && check_valid(c, r, ret->grid)) { |
| 1262 | ret->completed = TRUE; |
| 1263 | } |
| 1264 | |
| 1265 | return ret; /* made a valid move */ |
| 1266 | } |
| 1267 | |
| 1268 | return NULL; |
| 1269 | } |
| 1270 | |
| 1271 | /* ---------------------------------------------------------------------- |
| 1272 | * Drawing routines. |
| 1273 | */ |
| 1274 | |
| 1275 | struct game_drawstate { |
| 1276 | int started; |
| 1277 | int c, r, cr; |
| 1278 | digit *grid; |
| 1279 | unsigned char *hl; |
| 1280 | }; |
| 1281 | |
| 1282 | #define XSIZE(cr) ((cr) * TILE_SIZE + 2*BORDER + 1) |
| 1283 | #define YSIZE(cr) ((cr) * TILE_SIZE + 2*BORDER + 1) |
| 1284 | |
| 1285 | static void game_size(game_params *params, int *x, int *y) |
| 1286 | { |
| 1287 | int c = params->c, r = params->r, cr = c*r; |
| 1288 | |
| 1289 | *x = XSIZE(cr); |
| 1290 | *y = YSIZE(cr); |
| 1291 | } |
| 1292 | |
| 1293 | static float *game_colours(frontend *fe, game_state *state, int *ncolours) |
| 1294 | { |
| 1295 | float *ret = snewn(3 * NCOLOURS, float); |
| 1296 | |
| 1297 | frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]); |
| 1298 | |
| 1299 | ret[COL_GRID * 3 + 0] = 0.0F; |
| 1300 | ret[COL_GRID * 3 + 1] = 0.0F; |
| 1301 | ret[COL_GRID * 3 + 2] = 0.0F; |
| 1302 | |
| 1303 | ret[COL_CLUE * 3 + 0] = 0.0F; |
| 1304 | ret[COL_CLUE * 3 + 1] = 0.0F; |
| 1305 | ret[COL_CLUE * 3 + 2] = 0.0F; |
| 1306 | |
| 1307 | ret[COL_USER * 3 + 0] = 0.0F; |
| 1308 | ret[COL_USER * 3 + 1] = 0.6F * ret[COL_BACKGROUND * 3 + 1]; |
| 1309 | ret[COL_USER * 3 + 2] = 0.0F; |
| 1310 | |
| 1311 | ret[COL_HIGHLIGHT * 3 + 0] = 0.85F * ret[COL_BACKGROUND * 3 + 0]; |
| 1312 | ret[COL_HIGHLIGHT * 3 + 1] = 0.85F * ret[COL_BACKGROUND * 3 + 1]; |
| 1313 | ret[COL_HIGHLIGHT * 3 + 2] = 0.85F * ret[COL_BACKGROUND * 3 + 2]; |
| 1314 | |
| 1315 | *ncolours = NCOLOURS; |
| 1316 | return ret; |
| 1317 | } |
| 1318 | |
| 1319 | static game_drawstate *game_new_drawstate(game_state *state) |
| 1320 | { |
| 1321 | struct game_drawstate *ds = snew(struct game_drawstate); |
| 1322 | int c = state->c, r = state->r, cr = c*r; |
| 1323 | |
| 1324 | ds->started = FALSE; |
| 1325 | ds->c = c; |
| 1326 | ds->r = r; |
| 1327 | ds->cr = cr; |
| 1328 | ds->grid = snewn(cr*cr, digit); |
| 1329 | memset(ds->grid, 0, cr*cr); |
| 1330 | ds->hl = snewn(cr*cr, unsigned char); |
| 1331 | memset(ds->hl, 0, cr*cr); |
| 1332 | |
| 1333 | return ds; |
| 1334 | } |
| 1335 | |
| 1336 | static void game_free_drawstate(game_drawstate *ds) |
| 1337 | { |
| 1338 | sfree(ds->hl); |
| 1339 | sfree(ds->grid); |
| 1340 | sfree(ds); |
| 1341 | } |
| 1342 | |
| 1343 | static void draw_number(frontend *fe, game_drawstate *ds, game_state *state, |
| 1344 | int x, int y, int hl) |
| 1345 | { |
| 1346 | int c = state->c, r = state->r, cr = c*r; |
| 1347 | int tx, ty; |
| 1348 | int cx, cy, cw, ch; |
| 1349 | char str[2]; |
| 1350 | |
| 1351 | if (ds->grid[y*cr+x] == state->grid[y*cr+x] && ds->hl[y*cr+x] == hl) |
| 1352 | return; /* no change required */ |
| 1353 | |
| 1354 | tx = BORDER + x * TILE_SIZE + 2; |
| 1355 | ty = BORDER + y * TILE_SIZE + 2; |
| 1356 | |
| 1357 | cx = tx; |
| 1358 | cy = ty; |
| 1359 | cw = TILE_SIZE-3; |
| 1360 | ch = TILE_SIZE-3; |
| 1361 | |
| 1362 | if (x % r) |
| 1363 | cx--, cw++; |
| 1364 | if ((x+1) % r) |
| 1365 | cw++; |
| 1366 | if (y % c) |
| 1367 | cy--, ch++; |
| 1368 | if ((y+1) % c) |
| 1369 | ch++; |
| 1370 | |
| 1371 | clip(fe, cx, cy, cw, ch); |
| 1372 | |
| 1373 | /* background needs erasing? */ |
| 1374 | if (ds->grid[y*cr+x] || ds->hl[y*cr+x] != hl) |
| 1375 | draw_rect(fe, cx, cy, cw, ch, hl ? COL_HIGHLIGHT : COL_BACKGROUND); |
| 1376 | |
| 1377 | /* new number needs drawing? */ |
| 1378 | if (state->grid[y*cr+x]) { |
| 1379 | str[1] = '\0'; |
| 1380 | str[0] = state->grid[y*cr+x] + '0'; |
| 1381 | if (str[0] > '9') |
| 1382 | str[0] += 'a' - ('9'+1); |
| 1383 | draw_text(fe, tx + TILE_SIZE/2, ty + TILE_SIZE/2, |
| 1384 | FONT_VARIABLE, TILE_SIZE/2, ALIGN_VCENTRE | ALIGN_HCENTRE, |
| 1385 | state->immutable[y*cr+x] ? COL_CLUE : COL_USER, str); |
| 1386 | } |
| 1387 | |
| 1388 | unclip(fe); |
| 1389 | |
| 1390 | draw_update(fe, cx, cy, cw, ch); |
| 1391 | |
| 1392 | ds->grid[y*cr+x] = state->grid[y*cr+x]; |
| 1393 | ds->hl[y*cr+x] = hl; |
| 1394 | } |
| 1395 | |
| 1396 | static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate, |
| 1397 | game_state *state, int dir, game_ui *ui, |
| 1398 | float animtime, float flashtime) |
| 1399 | { |
| 1400 | int c = state->c, r = state->r, cr = c*r; |
| 1401 | int x, y; |
| 1402 | |
| 1403 | if (!ds->started) { |
| 1404 | /* |
| 1405 | * The initial contents of the window are not guaranteed |
| 1406 | * and can vary with front ends. To be on the safe side, |
| 1407 | * all games should start by drawing a big |
| 1408 | * background-colour rectangle covering the whole window. |
| 1409 | */ |
| 1410 | draw_rect(fe, 0, 0, XSIZE(cr), YSIZE(cr), COL_BACKGROUND); |
| 1411 | |
| 1412 | /* |
| 1413 | * Draw the grid. |
| 1414 | */ |
| 1415 | for (x = 0; x <= cr; x++) { |
| 1416 | int thick = (x % r ? 0 : 1); |
| 1417 | draw_rect(fe, BORDER + x*TILE_SIZE - thick, BORDER-1, |
| 1418 | 1+2*thick, cr*TILE_SIZE+3, COL_GRID); |
| 1419 | } |
| 1420 | for (y = 0; y <= cr; y++) { |
| 1421 | int thick = (y % c ? 0 : 1); |
| 1422 | draw_rect(fe, BORDER-1, BORDER + y*TILE_SIZE - thick, |
| 1423 | cr*TILE_SIZE+3, 1+2*thick, COL_GRID); |
| 1424 | } |
| 1425 | } |
| 1426 | |
| 1427 | /* |
| 1428 | * Draw any numbers which need redrawing. |
| 1429 | */ |
| 1430 | for (x = 0; x < cr; x++) { |
| 1431 | for (y = 0; y < cr; y++) { |
| 1432 | draw_number(fe, ds, state, x, y, |
| 1433 | (x == ui->hx && y == ui->hy) || |
| 1434 | (flashtime > 0 && |
| 1435 | (flashtime <= FLASH_TIME/3 || |
| 1436 | flashtime >= FLASH_TIME*2/3))); |
| 1437 | } |
| 1438 | } |
| 1439 | |
| 1440 | /* |
| 1441 | * Update the _entire_ grid if necessary. |
| 1442 | */ |
| 1443 | if (!ds->started) { |
| 1444 | draw_update(fe, 0, 0, XSIZE(cr), YSIZE(cr)); |
| 1445 | ds->started = TRUE; |
| 1446 | } |
| 1447 | } |
| 1448 | |
| 1449 | static float game_anim_length(game_state *oldstate, game_state *newstate, |
| 1450 | int dir) |
| 1451 | { |
| 1452 | return 0.0F; |
| 1453 | } |
| 1454 | |
| 1455 | static float game_flash_length(game_state *oldstate, game_state *newstate, |
| 1456 | int dir) |
| 1457 | { |
| 1458 | if (!oldstate->completed && newstate->completed) |
| 1459 | return FLASH_TIME; |
| 1460 | return 0.0F; |
| 1461 | } |
| 1462 | |
| 1463 | static int game_wants_statusbar(void) |
| 1464 | { |
| 1465 | return FALSE; |
| 1466 | } |
| 1467 | |
| 1468 | #ifdef COMBINED |
| 1469 | #define thegame solo |
| 1470 | #endif |
| 1471 | |
| 1472 | const struct game thegame = { |
| 1473 | "Solo", "games.solo", TRUE, |
| 1474 | default_params, |
| 1475 | game_fetch_preset, |
| 1476 | decode_params, |
| 1477 | encode_params, |
| 1478 | free_params, |
| 1479 | dup_params, |
| 1480 | game_configure, |
| 1481 | custom_params, |
| 1482 | validate_params, |
| 1483 | new_game_seed, |
| 1484 | validate_seed, |
| 1485 | new_game, |
| 1486 | dup_game, |
| 1487 | free_game, |
| 1488 | new_ui, |
| 1489 | free_ui, |
| 1490 | make_move, |
| 1491 | game_size, |
| 1492 | game_colours, |
| 1493 | game_new_drawstate, |
| 1494 | game_free_drawstate, |
| 1495 | game_redraw, |
| 1496 | game_anim_length, |
| 1497 | game_flash_length, |
| 1498 | game_wants_statusbar, |
| 1499 | }; |