| 1 | /* |
| 2 | * untangle.c: Game about planar graphs. You are given a graph |
| 3 | * represented by points and straight lines, with some lines |
| 4 | * crossing; your task is to drag the points into a configuration |
| 5 | * where none of the lines cross. |
| 6 | * |
| 7 | * Cloned from a Flash game called `Planarity', by John Tantalo. |
| 8 | * <http://home.cwru.edu/~jnt5/Planarity> at the time of writing |
| 9 | * this. The Flash game had a fixed set of levels; my added value, |
| 10 | * as usual, is automatic generation of random games to order. |
| 11 | */ |
| 12 | |
| 13 | /* |
| 14 | * TODO: |
| 15 | * |
| 16 | * - Docs and checklist etc |
| 17 | * - Any way we can speed up redraws on GTK? Uck. |
| 18 | */ |
| 19 | |
| 20 | #include <stdio.h> |
| 21 | #include <stdlib.h> |
| 22 | #include <string.h> |
| 23 | #include <assert.h> |
| 24 | #include <ctype.h> |
| 25 | #include <math.h> |
| 26 | |
| 27 | #include "puzzles.h" |
| 28 | #include "tree234.h" |
| 29 | |
| 30 | #define CIRCLE_RADIUS 6 |
| 31 | #define DRAG_THRESHOLD (CIRCLE_RADIUS * 2) |
| 32 | #define PREFERRED_TILESIZE 64 |
| 33 | |
| 34 | #define FLASH_TIME 0.13F |
| 35 | #define ANIM_TIME 0.13F |
| 36 | #define SOLVEANIM_TIME 0.50F |
| 37 | |
| 38 | enum { |
| 39 | COL_BACKGROUND, |
| 40 | COL_LINE, |
| 41 | COL_OUTLINE, |
| 42 | COL_POINT, |
| 43 | COL_DRAGPOINT, |
| 44 | COL_NEIGHBOUR, |
| 45 | NCOLOURS |
| 46 | }; |
| 47 | |
| 48 | typedef struct point { |
| 49 | /* |
| 50 | * Points are stored using rational coordinates, with the same |
| 51 | * denominator for both coordinates. |
| 52 | */ |
| 53 | int x, y, d; |
| 54 | } point; |
| 55 | |
| 56 | typedef struct edge { |
| 57 | /* |
| 58 | * This structure is implicitly associated with a particular |
| 59 | * point set, so all it has to do is to store two point |
| 60 | * indices. It is required to store them in the order (lower, |
| 61 | * higher), i.e. a < b always. |
| 62 | */ |
| 63 | int a, b; |
| 64 | } edge; |
| 65 | |
| 66 | struct game_params { |
| 67 | int n; /* number of points */ |
| 68 | }; |
| 69 | |
| 70 | struct graph { |
| 71 | int refcount; /* for deallocation */ |
| 72 | tree234 *edges; /* stores `edge' structures */ |
| 73 | }; |
| 74 | |
| 75 | struct game_state { |
| 76 | game_params params; |
| 77 | int w, h; /* extent of coordinate system only */ |
| 78 | point *pts; |
| 79 | struct graph *graph; |
| 80 | int completed, cheated, just_solved; |
| 81 | }; |
| 82 | |
| 83 | static int edgecmpC(const void *av, const void *bv) |
| 84 | { |
| 85 | const edge *a = (const edge *)av; |
| 86 | const edge *b = (const edge *)bv; |
| 87 | |
| 88 | if (a->a < b->a) |
| 89 | return -1; |
| 90 | else if (a->a > b->a) |
| 91 | return +1; |
| 92 | else if (a->b < b->b) |
| 93 | return -1; |
| 94 | else if (a->b > b->b) |
| 95 | return +1; |
| 96 | return 0; |
| 97 | } |
| 98 | |
| 99 | static int edgecmp(void *av, void *bv) { return edgecmpC(av, bv); } |
| 100 | |
| 101 | static game_params *default_params(void) |
| 102 | { |
| 103 | game_params *ret = snew(game_params); |
| 104 | |
| 105 | ret->n = 10; |
| 106 | |
| 107 | return ret; |
| 108 | } |
| 109 | |
| 110 | static int game_fetch_preset(int i, char **name, game_params **params) |
| 111 | { |
| 112 | game_params *ret; |
| 113 | int n; |
| 114 | char buf[80]; |
| 115 | |
| 116 | switch (i) { |
| 117 | case 0: n = 6; break; |
| 118 | case 1: n = 10; break; |
| 119 | case 2: n = 15; break; |
| 120 | case 3: n = 20; break; |
| 121 | case 4: n = 25; break; |
| 122 | default: return FALSE; |
| 123 | } |
| 124 | |
| 125 | sprintf(buf, "%d points", n); |
| 126 | *name = dupstr(buf); |
| 127 | |
| 128 | *params = ret = snew(game_params); |
| 129 | ret->n = n; |
| 130 | |
| 131 | return TRUE; |
| 132 | } |
| 133 | |
| 134 | static void free_params(game_params *params) |
| 135 | { |
| 136 | sfree(params); |
| 137 | } |
| 138 | |
| 139 | static game_params *dup_params(game_params *params) |
| 140 | { |
| 141 | game_params *ret = snew(game_params); |
| 142 | *ret = *params; /* structure copy */ |
| 143 | return ret; |
| 144 | } |
| 145 | |
| 146 | static void decode_params(game_params *params, char const *string) |
| 147 | { |
| 148 | params->n = atoi(string); |
| 149 | } |
| 150 | |
| 151 | static char *encode_params(game_params *params, int full) |
| 152 | { |
| 153 | char buf[80]; |
| 154 | |
| 155 | sprintf(buf, "%d", params->n); |
| 156 | |
| 157 | return dupstr(buf); |
| 158 | } |
| 159 | |
| 160 | static config_item *game_configure(game_params *params) |
| 161 | { |
| 162 | config_item *ret; |
| 163 | char buf[80]; |
| 164 | |
| 165 | ret = snewn(3, config_item); |
| 166 | |
| 167 | ret[0].name = "Number of points"; |
| 168 | ret[0].type = C_STRING; |
| 169 | sprintf(buf, "%d", params->n); |
| 170 | ret[0].sval = dupstr(buf); |
| 171 | ret[0].ival = 0; |
| 172 | |
| 173 | ret[1].name = NULL; |
| 174 | ret[1].type = C_END; |
| 175 | ret[1].sval = NULL; |
| 176 | ret[1].ival = 0; |
| 177 | |
| 178 | return ret; |
| 179 | } |
| 180 | |
| 181 | static game_params *custom_params(config_item *cfg) |
| 182 | { |
| 183 | game_params *ret = snew(game_params); |
| 184 | |
| 185 | ret->n = atoi(cfg[0].sval); |
| 186 | |
| 187 | return ret; |
| 188 | } |
| 189 | |
| 190 | static char *validate_params(game_params *params, int full) |
| 191 | { |
| 192 | if (params->n < 4) |
| 193 | return "Number of points must be at least four"; |
| 194 | return NULL; |
| 195 | } |
| 196 | |
| 197 | /* |
| 198 | * Determine whether the line segments between a1 and a2, and |
| 199 | * between b1 and b2, intersect. We count it as an intersection if |
| 200 | * any of the endpoints lies _on_ the other line. |
| 201 | */ |
| 202 | static int cross(point a1, point a2, point b1, point b2) |
| 203 | { |
| 204 | int b1x, b1y, b2x, b2y, px, py, d1, d2, d3; |
| 205 | |
| 206 | /* |
| 207 | * The condition for crossing is that b1 and b2 are on opposite |
| 208 | * sides of the line a1-a2, and vice versa. We determine this |
| 209 | * by taking the dot product of b1-a1 with a vector |
| 210 | * perpendicular to a2-a1, and similarly with b2-a1, and seeing |
| 211 | * if they have different signs. |
| 212 | */ |
| 213 | |
| 214 | /* |
| 215 | * Construct the vector b1-a1. We don't have to worry too much |
| 216 | * about the denominator, because we're only going to check the |
| 217 | * sign of this vector; we just need to get the numerator |
| 218 | * right. |
| 219 | */ |
| 220 | b1x = b1.x * a1.d - a1.x * b1.d; |
| 221 | b1y = b1.y * a1.d - a1.y * b1.d; |
| 222 | /* Now construct b2-a1, and a vector perpendicular to a2-a1, |
| 223 | * in the same way. */ |
| 224 | b2x = b2.x * a1.d - a1.x * b2.d; |
| 225 | b2y = b2.y * a1.d - a1.y * b2.d; |
| 226 | px = a1.y * a2.d - a2.y * a1.d; |
| 227 | py = a2.x * a1.d - a1.x * a2.d; |
| 228 | /* Take the dot products. */ |
| 229 | d1 = b1x * px + b1y * py; |
| 230 | d2 = b2x * px + b2y * py; |
| 231 | /* If they have the same non-zero sign, the lines do not cross. */ |
| 232 | if ((d1 > 0 && d2 > 0) || (d1 < 0 && d2 < 0)) |
| 233 | return FALSE; |
| 234 | |
| 235 | /* |
| 236 | * If the dot products are both exactly zero, then the two line |
| 237 | * segments are collinear. At this point the intersection |
| 238 | * condition becomes whether or not they overlap within their |
| 239 | * line. |
| 240 | */ |
| 241 | if (d1 == 0 && d2 == 0) { |
| 242 | /* Construct the vector a2-a1. */ |
| 243 | px = a2.x * a1.d - a1.x * a2.d; |
| 244 | py = a2.y * a1.d - a1.y * a2.d; |
| 245 | /* Determine the dot products of b1-a1 and b2-a1 with this. */ |
| 246 | d1 = b1x * px + b1y * py; |
| 247 | d2 = b2x * px + b2y * py; |
| 248 | /* If they're both strictly negative, the lines do not cross. */ |
| 249 | if (d1 < 0 && d2 < 0) |
| 250 | return FALSE; |
| 251 | /* Otherwise, take the dot product of a2-a1 with itself. If |
| 252 | * the other two dot products both exceed this, the lines do |
| 253 | * not cross. */ |
| 254 | d3 = px * px + py * py; |
| 255 | if (d1 > d3 && d2 > d3) |
| 256 | return FALSE; |
| 257 | } |
| 258 | |
| 259 | /* |
| 260 | * We've eliminated the only important special case, and we |
| 261 | * have determined that b1 and b2 are on opposite sides of the |
| 262 | * line a1-a2. Now do the same thing the other way round and |
| 263 | * we're done. |
| 264 | */ |
| 265 | b1x = a1.x * b1.d - b1.x * a1.d; |
| 266 | b1y = a1.y * b1.d - b1.y * a1.d; |
| 267 | b2x = a2.x * b1.d - b1.x * a2.d; |
| 268 | b2y = a2.y * b1.d - b1.y * a2.d; |
| 269 | px = b1.y * b2.d - b2.y * b1.d; |
| 270 | py = b2.x * b1.d - b1.x * b2.d; |
| 271 | d1 = b1x * px + b1y * py; |
| 272 | d2 = b2x * px + b2y * py; |
| 273 | if ((d1 > 0 && d2 > 0) || (d1 < 0 && d2 < 0)) |
| 274 | return FALSE; |
| 275 | |
| 276 | /* |
| 277 | * The lines must cross. |
| 278 | */ |
| 279 | return TRUE; |
| 280 | } |
| 281 | |
| 282 | static unsigned long squarert(unsigned long n) { |
| 283 | unsigned long d, a, b, di; |
| 284 | |
| 285 | d = n; |
| 286 | a = 0; |
| 287 | b = 1 << 30; /* largest available power of 4 */ |
| 288 | do { |
| 289 | a >>= 1; |
| 290 | di = 2*a + b; |
| 291 | if (di <= d) { |
| 292 | d -= di; |
| 293 | a += b; |
| 294 | } |
| 295 | b >>= 2; |
| 296 | } while (b); |
| 297 | |
| 298 | return a; |
| 299 | } |
| 300 | |
| 301 | /* |
| 302 | * Our solutions are arranged on a square grid big enough that n |
| 303 | * points occupy about 1/POINTDENSITY of the grid. |
| 304 | */ |
| 305 | #define POINTDENSITY 3 |
| 306 | #define MAXDEGREE 4 |
| 307 | #define COORDLIMIT(n) squarert((n) * POINTDENSITY) |
| 308 | |
| 309 | static void addedge(tree234 *edges, int a, int b) |
| 310 | { |
| 311 | edge *e = snew(edge); |
| 312 | |
| 313 | assert(a != b); |
| 314 | |
| 315 | e->a = min(a, b); |
| 316 | e->b = max(a, b); |
| 317 | |
| 318 | add234(edges, e); |
| 319 | } |
| 320 | |
| 321 | static int isedge(tree234 *edges, int a, int b) |
| 322 | { |
| 323 | edge e; |
| 324 | |
| 325 | assert(a != b); |
| 326 | |
| 327 | e.a = min(a, b); |
| 328 | e.b = max(a, b); |
| 329 | |
| 330 | return find234(edges, &e, NULL) != NULL; |
| 331 | } |
| 332 | |
| 333 | typedef struct vertex { |
| 334 | int param; |
| 335 | int vindex; |
| 336 | } vertex; |
| 337 | |
| 338 | static int vertcmpC(const void *av, const void *bv) |
| 339 | { |
| 340 | const vertex *a = (vertex *)av; |
| 341 | const vertex *b = (vertex *)bv; |
| 342 | |
| 343 | if (a->param < b->param) |
| 344 | return -1; |
| 345 | else if (a->param > b->param) |
| 346 | return +1; |
| 347 | else if (a->vindex < b->vindex) |
| 348 | return -1; |
| 349 | else if (a->vindex > b->vindex) |
| 350 | return +1; |
| 351 | return 0; |
| 352 | } |
| 353 | static int vertcmp(void *av, void *bv) { return vertcmpC(av, bv); } |
| 354 | |
| 355 | /* |
| 356 | * Construct point coordinates for n points arranged in a circle, |
| 357 | * within the bounding box (0,0) to (w,w). |
| 358 | */ |
| 359 | static void make_circle(point *pts, int n, int w) |
| 360 | { |
| 361 | int d, r, c, i; |
| 362 | |
| 363 | /* |
| 364 | * First, decide on a denominator. Although in principle it |
| 365 | * would be nice to set this really high so as to finely |
| 366 | * distinguish all the points on the circle, I'm going to set |
| 367 | * it at a fixed size to prevent integer overflow problems. |
| 368 | */ |
| 369 | d = PREFERRED_TILESIZE; |
| 370 | |
| 371 | /* |
| 372 | * Leave a little space outside the circle. |
| 373 | */ |
| 374 | c = d * w / 2; |
| 375 | r = d * w * 3 / 7; |
| 376 | |
| 377 | /* |
| 378 | * Place the points. |
| 379 | */ |
| 380 | for (i = 0; i < n; i++) { |
| 381 | double angle = i * 2 * PI / n; |
| 382 | double x = r * sin(angle), y = - r * cos(angle); |
| 383 | pts[i].x = (int)(c + x + 0.5); |
| 384 | pts[i].y = (int)(c + y + 0.5); |
| 385 | pts[i].d = d; |
| 386 | } |
| 387 | } |
| 388 | |
| 389 | static char *new_game_desc(game_params *params, random_state *rs, |
| 390 | char **aux, int interactive) |
| 391 | { |
| 392 | int n = params->n; |
| 393 | int w, h, i, j, k, m; |
| 394 | point *pts, *pts2; |
| 395 | int *tmp; |
| 396 | tree234 *edges, *vertices; |
| 397 | edge *e, *e2; |
| 398 | vertex *v, *vs, *vlist; |
| 399 | char *ret; |
| 400 | |
| 401 | w = h = COORDLIMIT(n); |
| 402 | |
| 403 | /* |
| 404 | * Choose n points from this grid. |
| 405 | */ |
| 406 | pts = snewn(n, point); |
| 407 | tmp = snewn(w*h, int); |
| 408 | for (i = 0; i < w*h; i++) |
| 409 | tmp[i] = i; |
| 410 | shuffle(tmp, w*h, sizeof(*tmp), rs); |
| 411 | for (i = 0; i < n; i++) { |
| 412 | pts[i].x = tmp[i] % w; |
| 413 | pts[i].y = tmp[i] / w; |
| 414 | pts[i].d = 1; |
| 415 | } |
| 416 | sfree(tmp); |
| 417 | |
| 418 | /* |
| 419 | * Now start adding edges between the points. |
| 420 | * |
| 421 | * At all times, we attempt to add an edge to the lowest-degree |
| 422 | * vertex we currently have, and we try the other vertices as |
| 423 | * candidate second endpoints in order of distance from this |
| 424 | * one. We stop as soon as we find an edge which |
| 425 | * |
| 426 | * (a) does not increase any vertex's degree beyond MAXDEGREE |
| 427 | * (b) does not cross any existing edges |
| 428 | * (c) does not intersect any actual point. |
| 429 | */ |
| 430 | vs = snewn(n, vertex); |
| 431 | vertices = newtree234(vertcmp); |
| 432 | for (i = 0; i < n; i++) { |
| 433 | v = vs + i; |
| 434 | v->param = 0; /* in this tree, param is the degree */ |
| 435 | v->vindex = i; |
| 436 | add234(vertices, v); |
| 437 | } |
| 438 | edges = newtree234(edgecmp); |
| 439 | vlist = snewn(n, vertex); |
| 440 | while (1) { |
| 441 | int added = FALSE; |
| 442 | |
| 443 | for (i = 0; i < n; i++) { |
| 444 | v = index234(vertices, i); |
| 445 | j = v->vindex; |
| 446 | |
| 447 | if (v->param >= MAXDEGREE) |
| 448 | break; /* nothing left to add! */ |
| 449 | |
| 450 | /* |
| 451 | * Sort the other vertices into order of their distance |
| 452 | * from this one. Don't bother looking below i, because |
| 453 | * we've already tried those edges the other way round. |
| 454 | * Also here we rule out target vertices with too high |
| 455 | * a degree, and (of course) ones to which we already |
| 456 | * have an edge. |
| 457 | */ |
| 458 | m = 0; |
| 459 | for (k = i+1; k < n; k++) { |
| 460 | vertex *kv = index234(vertices, k); |
| 461 | int ki = kv->vindex; |
| 462 | int dx, dy; |
| 463 | |
| 464 | if (kv->param >= MAXDEGREE || isedge(edges, ki, j)) |
| 465 | continue; |
| 466 | |
| 467 | vlist[m].vindex = ki; |
| 468 | dx = pts[ki].x - pts[j].x; |
| 469 | dy = pts[ki].y - pts[j].y; |
| 470 | vlist[m].param = dx*dx + dy*dy; |
| 471 | m++; |
| 472 | } |
| 473 | |
| 474 | qsort(vlist, m, sizeof(*vlist), vertcmpC); |
| 475 | |
| 476 | for (k = 0; k < m; k++) { |
| 477 | int p; |
| 478 | int ki = vlist[k].vindex; |
| 479 | |
| 480 | /* |
| 481 | * Check to see whether this edge intersects any |
| 482 | * existing edge or point. |
| 483 | */ |
| 484 | for (p = 0; p < n; p++) |
| 485 | if (p != ki && p != j && cross(pts[ki], pts[j], |
| 486 | pts[p], pts[p])) |
| 487 | break; |
| 488 | if (p < n) |
| 489 | continue; |
| 490 | for (p = 0; (e = index234(edges, p)) != NULL; p++) |
| 491 | if (e->a != ki && e->a != j && |
| 492 | e->b != ki && e->b != j && |
| 493 | cross(pts[ki], pts[j], pts[e->a], pts[e->b])) |
| 494 | break; |
| 495 | if (e) |
| 496 | continue; |
| 497 | |
| 498 | /* |
| 499 | * We're done! Add this edge, modify the degrees of |
| 500 | * the two vertices involved, and break. |
| 501 | */ |
| 502 | addedge(edges, j, ki); |
| 503 | added = TRUE; |
| 504 | del234(vertices, vs+j); |
| 505 | vs[j].param++; |
| 506 | add234(vertices, vs+j); |
| 507 | del234(vertices, vs+ki); |
| 508 | vs[ki].param++; |
| 509 | add234(vertices, vs+ki); |
| 510 | break; |
| 511 | } |
| 512 | |
| 513 | if (k < m) |
| 514 | break; |
| 515 | } |
| 516 | |
| 517 | if (!added) |
| 518 | break; /* we're done. */ |
| 519 | } |
| 520 | |
| 521 | /* |
| 522 | * That's our graph. Now shuffle the points, making sure that |
| 523 | * they come out with at least one crossed line when arranged |
| 524 | * in a circle (so that the puzzle isn't immediately solved!). |
| 525 | */ |
| 526 | tmp = snewn(n, int); |
| 527 | for (i = 0; i < n; i++) |
| 528 | tmp[i] = i; |
| 529 | pts2 = snewn(n, point); |
| 530 | make_circle(pts2, n, w); |
| 531 | while (1) { |
| 532 | shuffle(tmp, n, sizeof(*tmp), rs); |
| 533 | for (i = 0; (e = index234(edges, i)) != NULL; i++) { |
| 534 | for (j = i+1; (e2 = index234(edges, j)) != NULL; j++) { |
| 535 | if (e2->a == e->a || e2->a == e->b || |
| 536 | e2->b == e->a || e2->b == e->b) |
| 537 | continue; |
| 538 | if (cross(pts2[tmp[e2->a]], pts2[tmp[e2->b]], |
| 539 | pts2[tmp[e->a]], pts2[tmp[e->b]])) |
| 540 | break; |
| 541 | } |
| 542 | if (e2) |
| 543 | break; |
| 544 | } |
| 545 | if (e) |
| 546 | break; /* we've found a crossing */ |
| 547 | } |
| 548 | |
| 549 | /* |
| 550 | * We're done. Now encode the graph in a string format. Let's |
| 551 | * use a comma-separated list of dash-separated vertex number |
| 552 | * pairs, numbered from zero. We'll sort the list to prevent |
| 553 | * side channels. |
| 554 | */ |
| 555 | ret = NULL; |
| 556 | { |
| 557 | char *sep; |
| 558 | char buf[80]; |
| 559 | int retlen; |
| 560 | edge *ea; |
| 561 | |
| 562 | retlen = 0; |
| 563 | m = count234(edges); |
| 564 | ea = snewn(m, edge); |
| 565 | for (i = 0; (e = index234(edges, i)) != NULL; i++) { |
| 566 | assert(i < m); |
| 567 | ea[i].a = min(tmp[e->a], tmp[e->b]); |
| 568 | ea[i].b = max(tmp[e->a], tmp[e->b]); |
| 569 | retlen += 1 + sprintf(buf, "%d-%d", ea[i].a, ea[i].b); |
| 570 | } |
| 571 | assert(i == m); |
| 572 | qsort(ea, m, sizeof(*ea), edgecmpC); |
| 573 | |
| 574 | ret = snewn(retlen, char); |
| 575 | sep = ""; |
| 576 | k = 0; |
| 577 | |
| 578 | for (i = 0; i < m; i++) { |
| 579 | k += sprintf(ret + k, "%s%d-%d", sep, ea[i].a, ea[i].b); |
| 580 | sep = ","; |
| 581 | } |
| 582 | assert(k < retlen); |
| 583 | |
| 584 | sfree(ea); |
| 585 | } |
| 586 | |
| 587 | /* |
| 588 | * Encode the solution we started with as an aux_info string. |
| 589 | */ |
| 590 | { |
| 591 | char buf[80]; |
| 592 | char *auxstr; |
| 593 | int auxlen; |
| 594 | |
| 595 | auxlen = 2; /* leading 'S' and trailing '\0' */ |
| 596 | for (i = 0; i < n; i++) { |
| 597 | j = tmp[i]; |
| 598 | pts2[j] = pts[i]; |
| 599 | if (pts2[j].d & 1) { |
| 600 | pts2[j].x *= 2; |
| 601 | pts2[j].y *= 2; |
| 602 | pts2[j].d *= 2; |
| 603 | } |
| 604 | pts2[j].x += pts2[j].d / 2; |
| 605 | pts2[j].y += pts2[j].d / 2; |
| 606 | auxlen += sprintf(buf, ";P%d:%d,%d/%d", i, |
| 607 | pts2[j].x, pts2[j].y, pts2[j].d); |
| 608 | } |
| 609 | k = 0; |
| 610 | auxstr = snewn(auxlen, char); |
| 611 | auxstr[k++] = 'S'; |
| 612 | for (i = 0; i < n; i++) |
| 613 | k += sprintf(auxstr+k, ";P%d:%d,%d/%d", i, |
| 614 | pts2[i].x, pts2[i].y, pts2[i].d); |
| 615 | assert(k < auxlen); |
| 616 | *aux = auxstr; |
| 617 | } |
| 618 | sfree(pts2); |
| 619 | |
| 620 | sfree(tmp); |
| 621 | sfree(vlist); |
| 622 | freetree234(vertices); |
| 623 | sfree(vs); |
| 624 | while ((e = delpos234(edges, 0)) != NULL) |
| 625 | sfree(e); |
| 626 | freetree234(edges); |
| 627 | sfree(pts); |
| 628 | |
| 629 | return ret; |
| 630 | } |
| 631 | |
| 632 | static char *validate_desc(game_params *params, char *desc) |
| 633 | { |
| 634 | int a, b; |
| 635 | |
| 636 | while (*desc) { |
| 637 | a = atoi(desc); |
| 638 | if (a < 0 || a >= params->n) |
| 639 | return "Number out of range in game description"; |
| 640 | while (*desc && isdigit((unsigned char)*desc)) desc++; |
| 641 | if (*desc != '-') |
| 642 | return "Expected '-' after number in game description"; |
| 643 | desc++; /* eat dash */ |
| 644 | b = atoi(desc); |
| 645 | if (b < 0 || b >= params->n) |
| 646 | return "Number out of range in game description"; |
| 647 | while (*desc && isdigit((unsigned char)*desc)) desc++; |
| 648 | if (*desc) { |
| 649 | if (*desc != ',') |
| 650 | return "Expected ',' after number in game description"; |
| 651 | desc++; /* eat comma */ |
| 652 | } |
| 653 | } |
| 654 | |
| 655 | return NULL; |
| 656 | } |
| 657 | |
| 658 | static game_state *new_game(midend_data *me, game_params *params, char *desc) |
| 659 | { |
| 660 | int n = params->n; |
| 661 | game_state *state = snew(game_state); |
| 662 | int a, b; |
| 663 | |
| 664 | state->params = *params; |
| 665 | state->w = state->h = COORDLIMIT(n); |
| 666 | state->pts = snewn(n, point); |
| 667 | make_circle(state->pts, n, state->w); |
| 668 | state->graph = snew(struct graph); |
| 669 | state->graph->refcount = 1; |
| 670 | state->graph->edges = newtree234(edgecmp); |
| 671 | state->completed = state->cheated = state->just_solved = FALSE; |
| 672 | |
| 673 | while (*desc) { |
| 674 | a = atoi(desc); |
| 675 | assert(a >= 0 && a < params->n); |
| 676 | while (*desc && isdigit((unsigned char)*desc)) desc++; |
| 677 | assert(*desc == '-'); |
| 678 | desc++; /* eat dash */ |
| 679 | b = atoi(desc); |
| 680 | assert(b >= 0 && b < params->n); |
| 681 | while (*desc && isdigit((unsigned char)*desc)) desc++; |
| 682 | if (*desc) { |
| 683 | assert(*desc == ','); |
| 684 | desc++; /* eat comma */ |
| 685 | } |
| 686 | addedge(state->graph->edges, a, b); |
| 687 | } |
| 688 | |
| 689 | return state; |
| 690 | } |
| 691 | |
| 692 | static game_state *dup_game(game_state *state) |
| 693 | { |
| 694 | int n = state->params.n; |
| 695 | game_state *ret = snew(game_state); |
| 696 | |
| 697 | ret->params = state->params; |
| 698 | ret->w = state->w; |
| 699 | ret->h = state->h; |
| 700 | ret->pts = snewn(n, point); |
| 701 | memcpy(ret->pts, state->pts, n * sizeof(point)); |
| 702 | ret->graph = state->graph; |
| 703 | ret->graph->refcount++; |
| 704 | ret->completed = state->completed; |
| 705 | ret->cheated = state->cheated; |
| 706 | ret->just_solved = state->just_solved; |
| 707 | |
| 708 | return ret; |
| 709 | } |
| 710 | |
| 711 | static void free_game(game_state *state) |
| 712 | { |
| 713 | if (--state->graph->refcount <= 0) { |
| 714 | edge *e; |
| 715 | while ((e = delpos234(state->graph->edges, 0)) != NULL) |
| 716 | sfree(e); |
| 717 | freetree234(state->graph->edges); |
| 718 | sfree(state->graph); |
| 719 | } |
| 720 | sfree(state->pts); |
| 721 | sfree(state); |
| 722 | } |
| 723 | |
| 724 | static char *solve_game(game_state *state, game_state *currstate, |
| 725 | char *aux, char **error) |
| 726 | { |
| 727 | if (!aux) { |
| 728 | *error = "Solution not known for this puzzle"; |
| 729 | return NULL; |
| 730 | } |
| 731 | |
| 732 | return dupstr(aux); |
| 733 | } |
| 734 | |
| 735 | static char *game_text_format(game_state *state) |
| 736 | { |
| 737 | return NULL; |
| 738 | } |
| 739 | |
| 740 | struct game_ui { |
| 741 | int dragpoint; /* point being dragged; -1 if none */ |
| 742 | point newpoint; /* where it's been dragged to so far */ |
| 743 | int just_dragged; /* reset in game_changed_state */ |
| 744 | int just_moved; /* _set_ in game_changed_state */ |
| 745 | float anim_length; |
| 746 | }; |
| 747 | |
| 748 | static game_ui *new_ui(game_state *state) |
| 749 | { |
| 750 | game_ui *ui = snew(game_ui); |
| 751 | ui->dragpoint = -1; |
| 752 | ui->just_moved = ui->just_dragged = FALSE; |
| 753 | return ui; |
| 754 | } |
| 755 | |
| 756 | static void free_ui(game_ui *ui) |
| 757 | { |
| 758 | sfree(ui); |
| 759 | } |
| 760 | |
| 761 | static char *encode_ui(game_ui *ui) |
| 762 | { |
| 763 | return NULL; |
| 764 | } |
| 765 | |
| 766 | static void decode_ui(game_ui *ui, char *encoding) |
| 767 | { |
| 768 | } |
| 769 | |
| 770 | static void game_changed_state(game_ui *ui, game_state *oldstate, |
| 771 | game_state *newstate) |
| 772 | { |
| 773 | ui->dragpoint = -1; |
| 774 | ui->just_moved = ui->just_dragged; |
| 775 | ui->just_dragged = FALSE; |
| 776 | } |
| 777 | |
| 778 | struct game_drawstate { |
| 779 | int tilesize; |
| 780 | }; |
| 781 | |
| 782 | static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds, |
| 783 | int x, int y, int button) |
| 784 | { |
| 785 | int n = state->params.n; |
| 786 | |
| 787 | if (button == LEFT_BUTTON) { |
| 788 | int i, best, bestd; |
| 789 | |
| 790 | /* |
| 791 | * Begin drag. We drag the vertex _nearest_ to the pointer, |
| 792 | * just in case one is nearly on top of another and we want |
| 793 | * to drag the latter. However, we drag nothing at all if |
| 794 | * the nearest vertex is outside DRAG_THRESHOLD. |
| 795 | */ |
| 796 | best = -1; |
| 797 | bestd = 0; |
| 798 | |
| 799 | for (i = 0; i < n; i++) { |
| 800 | int px = state->pts[i].x * ds->tilesize / state->pts[i].d; |
| 801 | int py = state->pts[i].y * ds->tilesize / state->pts[i].d; |
| 802 | int dx = px - x; |
| 803 | int dy = py - y; |
| 804 | int d = dx*dx + dy*dy; |
| 805 | |
| 806 | if (best == -1 || bestd > d) { |
| 807 | best = i; |
| 808 | bestd = d; |
| 809 | } |
| 810 | } |
| 811 | |
| 812 | if (bestd <= DRAG_THRESHOLD * DRAG_THRESHOLD) { |
| 813 | ui->dragpoint = best; |
| 814 | ui->newpoint.x = x; |
| 815 | ui->newpoint.y = y; |
| 816 | ui->newpoint.d = ds->tilesize; |
| 817 | return ""; |
| 818 | } |
| 819 | |
| 820 | } else if (button == LEFT_DRAG && ui->dragpoint >= 0) { |
| 821 | ui->newpoint.x = x; |
| 822 | ui->newpoint.y = y; |
| 823 | ui->newpoint.d = ds->tilesize; |
| 824 | return ""; |
| 825 | } else if (button == LEFT_RELEASE && ui->dragpoint >= 0) { |
| 826 | int p = ui->dragpoint; |
| 827 | char buf[80]; |
| 828 | |
| 829 | ui->dragpoint = -1; /* terminate drag, no matter what */ |
| 830 | |
| 831 | /* |
| 832 | * First, see if we're within range. The user can cancel a |
| 833 | * drag by dragging the point right off the window. |
| 834 | */ |
| 835 | if (ui->newpoint.x < 0 || ui->newpoint.x >= state->w*ui->newpoint.d || |
| 836 | ui->newpoint.y < 0 || ui->newpoint.y >= state->h*ui->newpoint.d) |
| 837 | return ""; |
| 838 | |
| 839 | /* |
| 840 | * We aren't cancelling the drag. Construct a move string |
| 841 | * indicating where this point is going to. |
| 842 | */ |
| 843 | sprintf(buf, "P%d:%d,%d/%d", p, |
| 844 | ui->newpoint.x, ui->newpoint.y, ui->newpoint.d); |
| 845 | ui->just_dragged = TRUE; |
| 846 | return dupstr(buf); |
| 847 | } |
| 848 | |
| 849 | return NULL; |
| 850 | } |
| 851 | |
| 852 | static game_state *execute_move(game_state *state, char *move) |
| 853 | { |
| 854 | int n = state->params.n; |
| 855 | int p, x, y, d, k; |
| 856 | game_state *ret = dup_game(state); |
| 857 | |
| 858 | ret->just_solved = FALSE; |
| 859 | |
| 860 | while (*move) { |
| 861 | if (*move == 'S') { |
| 862 | move++; |
| 863 | if (*move == ';') move++; |
| 864 | ret->cheated = ret->just_solved = TRUE; |
| 865 | } |
| 866 | if (*move == 'P' && |
| 867 | sscanf(move+1, "%d:%d,%d/%d%n", &p, &x, &y, &d, &k) == 4 && |
| 868 | p >= 0 && p < n && d > 0) { |
| 869 | ret->pts[p].x = x; |
| 870 | ret->pts[p].y = y; |
| 871 | ret->pts[p].d = d; |
| 872 | |
| 873 | move += k+1; |
| 874 | if (*move == ';') move++; |
| 875 | } else { |
| 876 | free_game(ret); |
| 877 | return NULL; |
| 878 | } |
| 879 | } |
| 880 | |
| 881 | /* |
| 882 | * Check correctness: for every pair of edges, see whether they |
| 883 | * cross. |
| 884 | */ |
| 885 | if (!ret->completed) { |
| 886 | int i, j; |
| 887 | edge *e, *e2; |
| 888 | |
| 889 | for (i = 0; (e = index234(ret->graph->edges, i)) != NULL; i++) { |
| 890 | for (j = i+1; (e2 = index234(ret->graph->edges, j)) != NULL; j++) { |
| 891 | if (e2->a == e->a || e2->a == e->b || |
| 892 | e2->b == e->a || e2->b == e->b) |
| 893 | continue; |
| 894 | if (cross(ret->pts[e2->a], ret->pts[e2->b], |
| 895 | ret->pts[e->a], ret->pts[e->b])) |
| 896 | break; |
| 897 | } |
| 898 | if (e2) |
| 899 | break; |
| 900 | } |
| 901 | |
| 902 | /* |
| 903 | * e == NULL if we've gone through all the edge pairs |
| 904 | * without finding a crossing. |
| 905 | */ |
| 906 | ret->completed = (e == NULL); |
| 907 | } |
| 908 | |
| 909 | return ret; |
| 910 | } |
| 911 | |
| 912 | /* ---------------------------------------------------------------------- |
| 913 | * Drawing routines. |
| 914 | */ |
| 915 | |
| 916 | static void game_compute_size(game_params *params, int tilesize, |
| 917 | int *x, int *y) |
| 918 | { |
| 919 | *x = *y = COORDLIMIT(params->n) * tilesize; |
| 920 | } |
| 921 | |
| 922 | static void game_set_size(game_drawstate *ds, game_params *params, |
| 923 | int tilesize) |
| 924 | { |
| 925 | ds->tilesize = tilesize; |
| 926 | } |
| 927 | |
| 928 | static float *game_colours(frontend *fe, game_state *state, int *ncolours) |
| 929 | { |
| 930 | float *ret = snewn(3 * NCOLOURS, float); |
| 931 | |
| 932 | frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]); |
| 933 | |
| 934 | ret[COL_LINE * 3 + 0] = 0.0F; |
| 935 | ret[COL_LINE * 3 + 1] = 0.0F; |
| 936 | ret[COL_LINE * 3 + 2] = 0.0F; |
| 937 | |
| 938 | ret[COL_OUTLINE * 3 + 0] = 0.0F; |
| 939 | ret[COL_OUTLINE * 3 + 1] = 0.0F; |
| 940 | ret[COL_OUTLINE * 3 + 2] = 0.0F; |
| 941 | |
| 942 | ret[COL_POINT * 3 + 0] = 0.0F; |
| 943 | ret[COL_POINT * 3 + 1] = 0.0F; |
| 944 | ret[COL_POINT * 3 + 2] = 1.0F; |
| 945 | |
| 946 | ret[COL_DRAGPOINT * 3 + 0] = 1.0F; |
| 947 | ret[COL_DRAGPOINT * 3 + 1] = 1.0F; |
| 948 | ret[COL_DRAGPOINT * 3 + 2] = 1.0F; |
| 949 | |
| 950 | ret[COL_NEIGHBOUR * 3 + 0] = 1.0F; |
| 951 | ret[COL_NEIGHBOUR * 3 + 1] = 0.0F; |
| 952 | ret[COL_NEIGHBOUR * 3 + 2] = 0.0F; |
| 953 | |
| 954 | *ncolours = NCOLOURS; |
| 955 | return ret; |
| 956 | } |
| 957 | |
| 958 | static game_drawstate *game_new_drawstate(game_state *state) |
| 959 | { |
| 960 | struct game_drawstate *ds = snew(struct game_drawstate); |
| 961 | |
| 962 | ds->tilesize = 0; |
| 963 | |
| 964 | return ds; |
| 965 | } |
| 966 | |
| 967 | static void game_free_drawstate(game_drawstate *ds) |
| 968 | { |
| 969 | sfree(ds); |
| 970 | } |
| 971 | |
| 972 | static point mix(point a, point b, float distance) |
| 973 | { |
| 974 | point ret; |
| 975 | |
| 976 | ret.d = a.d * b.d; |
| 977 | ret.x = a.x * b.d + distance * (b.x * a.d - a.x * b.d); |
| 978 | ret.y = a.y * b.d + distance * (b.y * a.d - a.y * b.d); |
| 979 | |
| 980 | return ret; |
| 981 | } |
| 982 | |
| 983 | static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate, |
| 984 | game_state *state, int dir, game_ui *ui, |
| 985 | float animtime, float flashtime) |
| 986 | { |
| 987 | int w, h; |
| 988 | edge *e; |
| 989 | int i, j; |
| 990 | int bg; |
| 991 | |
| 992 | /* |
| 993 | * There's no terribly sensible way to do partial redraws of |
| 994 | * this game, so I'm going to have to resort to redrawing the |
| 995 | * whole thing every time. |
| 996 | */ |
| 997 | |
| 998 | bg = (flashtime != 0 ? COL_DRAGPOINT : COL_BACKGROUND); |
| 999 | game_compute_size(&state->params, ds->tilesize, &w, &h); |
| 1000 | draw_rect(fe, 0, 0, w, h, bg); |
| 1001 | |
| 1002 | /* |
| 1003 | * Draw the edges. |
| 1004 | */ |
| 1005 | |
| 1006 | for (i = 0; (e = index234(state->graph->edges, i)) != NULL; i++) { |
| 1007 | point p1, p2; |
| 1008 | int x1, y1, x2, y2; |
| 1009 | |
| 1010 | p1 = state->pts[e->a]; |
| 1011 | p2 = state->pts[e->b]; |
| 1012 | if (ui->dragpoint == e->a) |
| 1013 | p1 = ui->newpoint; |
| 1014 | else if (ui->dragpoint == e->b) |
| 1015 | p2 = ui->newpoint; |
| 1016 | |
| 1017 | if (oldstate) { |
| 1018 | p1 = mix(oldstate->pts[e->a], p1, animtime / ui->anim_length); |
| 1019 | p2 = mix(oldstate->pts[e->b], p2, animtime / ui->anim_length); |
| 1020 | } |
| 1021 | |
| 1022 | x1 = p1.x * ds->tilesize / p1.d; |
| 1023 | y1 = p1.y * ds->tilesize / p1.d; |
| 1024 | x2 = p2.x * ds->tilesize / p2.d; |
| 1025 | y2 = p2.y * ds->tilesize / p2.d; |
| 1026 | |
| 1027 | draw_line(fe, x1, y1, x2, y2, COL_LINE); |
| 1028 | } |
| 1029 | |
| 1030 | /* |
| 1031 | * Draw the points. |
| 1032 | * |
| 1033 | * When dragging, we should not only vary the colours, but |
| 1034 | * leave the point being dragged until last. |
| 1035 | */ |
| 1036 | for (j = 0; j < 3; j++) { |
| 1037 | int thisc = (j == 0 ? COL_POINT : |
| 1038 | j == 1 ? COL_NEIGHBOUR : COL_DRAGPOINT); |
| 1039 | for (i = 0; i < state->params.n; i++) { |
| 1040 | int x, y, c; |
| 1041 | point p = state->pts[i]; |
| 1042 | |
| 1043 | if (ui->dragpoint == i) { |
| 1044 | p = ui->newpoint; |
| 1045 | c = COL_DRAGPOINT; |
| 1046 | } else if (ui->dragpoint >= 0 && |
| 1047 | isedge(state->graph->edges, ui->dragpoint, i)) { |
| 1048 | c = COL_NEIGHBOUR; |
| 1049 | } else { |
| 1050 | c = COL_POINT; |
| 1051 | } |
| 1052 | |
| 1053 | if (oldstate) |
| 1054 | p = mix(oldstate->pts[i], p, animtime / ui->anim_length); |
| 1055 | |
| 1056 | if (c == thisc) { |
| 1057 | x = p.x * ds->tilesize / p.d; |
| 1058 | y = p.y * ds->tilesize / p.d; |
| 1059 | |
| 1060 | #ifdef VERTEX_NUMBERS |
| 1061 | draw_circle(fe, x, y, DRAG_THRESHOLD, bg, bg); |
| 1062 | { |
| 1063 | char buf[80]; |
| 1064 | sprintf(buf, "%d", i); |
| 1065 | draw_text(fe, x, y, FONT_VARIABLE, DRAG_THRESHOLD*3/2, |
| 1066 | ALIGN_VCENTRE|ALIGN_HCENTRE, c, buf); |
| 1067 | } |
| 1068 | #else |
| 1069 | draw_circle(fe, x, y, CIRCLE_RADIUS, c, COL_OUTLINE); |
| 1070 | #endif |
| 1071 | } |
| 1072 | } |
| 1073 | } |
| 1074 | |
| 1075 | draw_update(fe, 0, 0, w, h); |
| 1076 | } |
| 1077 | |
| 1078 | static float game_anim_length(game_state *oldstate, game_state *newstate, |
| 1079 | int dir, game_ui *ui) |
| 1080 | { |
| 1081 | if (ui->just_moved) |
| 1082 | return 0.0F; |
| 1083 | if ((dir < 0 ? oldstate : newstate)->just_solved) |
| 1084 | ui->anim_length = SOLVEANIM_TIME; |
| 1085 | else |
| 1086 | ui->anim_length = ANIM_TIME; |
| 1087 | return ui->anim_length; |
| 1088 | } |
| 1089 | |
| 1090 | static float game_flash_length(game_state *oldstate, game_state *newstate, |
| 1091 | int dir, game_ui *ui) |
| 1092 | { |
| 1093 | if (!oldstate->completed && newstate->completed && |
| 1094 | !oldstate->cheated && !newstate->cheated) |
| 1095 | return FLASH_TIME; |
| 1096 | return 0.0F; |
| 1097 | } |
| 1098 | |
| 1099 | static int game_wants_statusbar(void) |
| 1100 | { |
| 1101 | return FALSE; |
| 1102 | } |
| 1103 | |
| 1104 | static int game_timing_state(game_state *state, game_ui *ui) |
| 1105 | { |
| 1106 | return TRUE; |
| 1107 | } |
| 1108 | |
| 1109 | #ifdef COMBINED |
| 1110 | #define thegame untangle |
| 1111 | #endif |
| 1112 | |
| 1113 | const struct game thegame = { |
| 1114 | "Untangle", "games.untangle", |
| 1115 | default_params, |
| 1116 | game_fetch_preset, |
| 1117 | decode_params, |
| 1118 | encode_params, |
| 1119 | free_params, |
| 1120 | dup_params, |
| 1121 | TRUE, game_configure, custom_params, |
| 1122 | validate_params, |
| 1123 | new_game_desc, |
| 1124 | validate_desc, |
| 1125 | new_game, |
| 1126 | dup_game, |
| 1127 | free_game, |
| 1128 | TRUE, solve_game, |
| 1129 | FALSE, game_text_format, |
| 1130 | new_ui, |
| 1131 | free_ui, |
| 1132 | encode_ui, |
| 1133 | decode_ui, |
| 1134 | game_changed_state, |
| 1135 | interpret_move, |
| 1136 | execute_move, |
| 1137 | PREFERRED_TILESIZE, game_compute_size, game_set_size, |
| 1138 | game_colours, |
| 1139 | game_new_drawstate, |
| 1140 | game_free_drawstate, |
| 1141 | game_redraw, |
| 1142 | game_anim_length, |
| 1143 | game_flash_length, |
| 1144 | game_wants_statusbar, |
| 1145 | FALSE, game_timing_state, |
| 1146 | SOLVE_ANIMATES, /* mouse_priorities */ |
| 1147 | }; |