9d6c3859 |
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 | |
8eef6b92 |
34 | #define FLASH_TIME 0.30F |
9d6c3859 |
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, |
8eef6b92 |
45 | COL_FLASH1, |
46 | COL_FLASH2, |
9d6c3859 |
47 | NCOLOURS |
48 | }; |
49 | |
50 | typedef struct point { |
51 | /* |
52 | * Points are stored using rational coordinates, with the same |
53 | * denominator for both coordinates. |
54 | */ |
42159ec6 |
55 | long x, y, d; |
9d6c3859 |
56 | } point; |
57 | |
58 | typedef struct edge { |
59 | /* |
60 | * This structure is implicitly associated with a particular |
61 | * point set, so all it has to do is to store two point |
62 | * indices. It is required to store them in the order (lower, |
63 | * higher), i.e. a < b always. |
64 | */ |
65 | int a, b; |
66 | } edge; |
67 | |
68 | struct game_params { |
69 | int n; /* number of points */ |
70 | }; |
71 | |
72 | struct graph { |
73 | int refcount; /* for deallocation */ |
74 | tree234 *edges; /* stores `edge' structures */ |
75 | }; |
76 | |
77 | struct game_state { |
78 | game_params params; |
79 | int w, h; /* extent of coordinate system only */ |
80 | point *pts; |
81 | struct graph *graph; |
82 | int completed, cheated, just_solved; |
83 | }; |
84 | |
85 | static int edgecmpC(const void *av, const void *bv) |
86 | { |
87 | const edge *a = (const edge *)av; |
88 | const edge *b = (const edge *)bv; |
89 | |
90 | if (a->a < b->a) |
91 | return -1; |
92 | else if (a->a > b->a) |
93 | return +1; |
94 | else if (a->b < b->b) |
95 | return -1; |
96 | else if (a->b > b->b) |
97 | return +1; |
98 | return 0; |
99 | } |
100 | |
101 | static int edgecmp(void *av, void *bv) { return edgecmpC(av, bv); } |
102 | |
103 | static game_params *default_params(void) |
104 | { |
105 | game_params *ret = snew(game_params); |
106 | |
107 | ret->n = 10; |
108 | |
109 | return ret; |
110 | } |
111 | |
112 | static int game_fetch_preset(int i, char **name, game_params **params) |
113 | { |
114 | game_params *ret; |
115 | int n; |
116 | char buf[80]; |
117 | |
118 | switch (i) { |
119 | case 0: n = 6; break; |
120 | case 1: n = 10; break; |
121 | case 2: n = 15; break; |
122 | case 3: n = 20; break; |
123 | case 4: n = 25; break; |
124 | default: return FALSE; |
125 | } |
126 | |
127 | sprintf(buf, "%d points", n); |
128 | *name = dupstr(buf); |
129 | |
130 | *params = ret = snew(game_params); |
131 | ret->n = n; |
132 | |
133 | return TRUE; |
134 | } |
135 | |
136 | static void free_params(game_params *params) |
137 | { |
138 | sfree(params); |
139 | } |
140 | |
141 | static game_params *dup_params(game_params *params) |
142 | { |
143 | game_params *ret = snew(game_params); |
144 | *ret = *params; /* structure copy */ |
145 | return ret; |
146 | } |
147 | |
148 | static void decode_params(game_params *params, char const *string) |
149 | { |
150 | params->n = atoi(string); |
151 | } |
152 | |
153 | static char *encode_params(game_params *params, int full) |
154 | { |
155 | char buf[80]; |
156 | |
157 | sprintf(buf, "%d", params->n); |
158 | |
159 | return dupstr(buf); |
160 | } |
161 | |
162 | static config_item *game_configure(game_params *params) |
163 | { |
164 | config_item *ret; |
165 | char buf[80]; |
166 | |
167 | ret = snewn(3, config_item); |
168 | |
169 | ret[0].name = "Number of points"; |
170 | ret[0].type = C_STRING; |
171 | sprintf(buf, "%d", params->n); |
172 | ret[0].sval = dupstr(buf); |
173 | ret[0].ival = 0; |
174 | |
175 | ret[1].name = NULL; |
176 | ret[1].type = C_END; |
177 | ret[1].sval = NULL; |
178 | ret[1].ival = 0; |
179 | |
180 | return ret; |
181 | } |
182 | |
183 | static game_params *custom_params(config_item *cfg) |
184 | { |
185 | game_params *ret = snew(game_params); |
186 | |
187 | ret->n = atoi(cfg[0].sval); |
188 | |
189 | return ret; |
190 | } |
191 | |
192 | static char *validate_params(game_params *params, int full) |
193 | { |
194 | if (params->n < 4) |
195 | return "Number of points must be at least four"; |
196 | return NULL; |
197 | } |
198 | |
199 | /* |
200 | * Determine whether the line segments between a1 and a2, and |
201 | * between b1 and b2, intersect. We count it as an intersection if |
202 | * any of the endpoints lies _on_ the other line. |
203 | */ |
204 | static int cross(point a1, point a2, point b1, point b2) |
205 | { |
42159ec6 |
206 | long b1x, b1y, b2x, b2y, px, py, d1, d2, d3; |
9d6c3859 |
207 | |
208 | /* |
209 | * The condition for crossing is that b1 and b2 are on opposite |
210 | * sides of the line a1-a2, and vice versa. We determine this |
211 | * by taking the dot product of b1-a1 with a vector |
212 | * perpendicular to a2-a1, and similarly with b2-a1, and seeing |
213 | * if they have different signs. |
214 | */ |
215 | |
216 | /* |
217 | * Construct the vector b1-a1. We don't have to worry too much |
218 | * about the denominator, because we're only going to check the |
219 | * sign of this vector; we just need to get the numerator |
220 | * right. |
221 | */ |
222 | b1x = b1.x * a1.d - a1.x * b1.d; |
223 | b1y = b1.y * a1.d - a1.y * b1.d; |
224 | /* Now construct b2-a1, and a vector perpendicular to a2-a1, |
225 | * in the same way. */ |
226 | b2x = b2.x * a1.d - a1.x * b2.d; |
227 | b2y = b2.y * a1.d - a1.y * b2.d; |
228 | px = a1.y * a2.d - a2.y * a1.d; |
229 | py = a2.x * a1.d - a1.x * a2.d; |
230 | /* Take the dot products. */ |
231 | d1 = b1x * px + b1y * py; |
232 | d2 = b2x * px + b2y * py; |
233 | /* If they have the same non-zero sign, the lines do not cross. */ |
234 | if ((d1 > 0 && d2 > 0) || (d1 < 0 && d2 < 0)) |
235 | return FALSE; |
236 | |
237 | /* |
238 | * If the dot products are both exactly zero, then the two line |
239 | * segments are collinear. At this point the intersection |
240 | * condition becomes whether or not they overlap within their |
241 | * line. |
242 | */ |
243 | if (d1 == 0 && d2 == 0) { |
244 | /* Construct the vector a2-a1. */ |
245 | px = a2.x * a1.d - a1.x * a2.d; |
246 | py = a2.y * a1.d - a1.y * a2.d; |
247 | /* Determine the dot products of b1-a1 and b2-a1 with this. */ |
248 | d1 = b1x * px + b1y * py; |
249 | d2 = b2x * px + b2y * py; |
250 | /* If they're both strictly negative, the lines do not cross. */ |
251 | if (d1 < 0 && d2 < 0) |
252 | return FALSE; |
253 | /* Otherwise, take the dot product of a2-a1 with itself. If |
254 | * the other two dot products both exceed this, the lines do |
255 | * not cross. */ |
256 | d3 = px * px + py * py; |
257 | if (d1 > d3 && d2 > d3) |
258 | return FALSE; |
259 | } |
260 | |
261 | /* |
262 | * We've eliminated the only important special case, and we |
263 | * have determined that b1 and b2 are on opposite sides of the |
264 | * line a1-a2. Now do the same thing the other way round and |
265 | * we're done. |
266 | */ |
267 | b1x = a1.x * b1.d - b1.x * a1.d; |
268 | b1y = a1.y * b1.d - b1.y * a1.d; |
269 | b2x = a2.x * b1.d - b1.x * a2.d; |
270 | b2y = a2.y * b1.d - b1.y * a2.d; |
271 | px = b1.y * b2.d - b2.y * b1.d; |
272 | py = b2.x * b1.d - b1.x * b2.d; |
273 | d1 = b1x * px + b1y * py; |
274 | d2 = b2x * px + b2y * py; |
275 | if ((d1 > 0 && d2 > 0) || (d1 < 0 && d2 < 0)) |
276 | return FALSE; |
277 | |
278 | /* |
279 | * The lines must cross. |
280 | */ |
281 | return TRUE; |
282 | } |
283 | |
284 | static unsigned long squarert(unsigned long n) { |
285 | unsigned long d, a, b, di; |
286 | |
287 | d = n; |
288 | a = 0; |
1ad942e7 |
289 | b = 1L << 30; /* largest available power of 4 */ |
9d6c3859 |
290 | do { |
291 | a >>= 1; |
292 | di = 2*a + b; |
293 | if (di <= d) { |
294 | d -= di; |
295 | a += b; |
296 | } |
297 | b >>= 2; |
298 | } while (b); |
299 | |
300 | return a; |
301 | } |
302 | |
303 | /* |
304 | * Our solutions are arranged on a square grid big enough that n |
305 | * points occupy about 1/POINTDENSITY of the grid. |
306 | */ |
307 | #define POINTDENSITY 3 |
308 | #define MAXDEGREE 4 |
309 | #define COORDLIMIT(n) squarert((n) * POINTDENSITY) |
310 | |
311 | static void addedge(tree234 *edges, int a, int b) |
312 | { |
313 | edge *e = snew(edge); |
314 | |
315 | assert(a != b); |
316 | |
317 | e->a = min(a, b); |
318 | e->b = max(a, b); |
319 | |
320 | add234(edges, e); |
321 | } |
322 | |
323 | static int isedge(tree234 *edges, int a, int b) |
324 | { |
325 | edge e; |
326 | |
327 | assert(a != b); |
328 | |
329 | e.a = min(a, b); |
330 | e.b = max(a, b); |
331 | |
332 | return find234(edges, &e, NULL) != NULL; |
333 | } |
334 | |
335 | typedef struct vertex { |
336 | int param; |
337 | int vindex; |
338 | } vertex; |
339 | |
340 | static int vertcmpC(const void *av, const void *bv) |
341 | { |
342 | const vertex *a = (vertex *)av; |
343 | const vertex *b = (vertex *)bv; |
344 | |
345 | if (a->param < b->param) |
346 | return -1; |
347 | else if (a->param > b->param) |
348 | return +1; |
349 | else if (a->vindex < b->vindex) |
350 | return -1; |
351 | else if (a->vindex > b->vindex) |
352 | return +1; |
353 | return 0; |
354 | } |
355 | static int vertcmp(void *av, void *bv) { return vertcmpC(av, bv); } |
356 | |
357 | /* |
358 | * Construct point coordinates for n points arranged in a circle, |
359 | * within the bounding box (0,0) to (w,w). |
360 | */ |
361 | static void make_circle(point *pts, int n, int w) |
362 | { |
42159ec6 |
363 | long d, r, c, i; |
9d6c3859 |
364 | |
365 | /* |
366 | * First, decide on a denominator. Although in principle it |
367 | * would be nice to set this really high so as to finely |
368 | * distinguish all the points on the circle, I'm going to set |
369 | * it at a fixed size to prevent integer overflow problems. |
370 | */ |
371 | d = PREFERRED_TILESIZE; |
372 | |
373 | /* |
374 | * Leave a little space outside the circle. |
375 | */ |
376 | c = d * w / 2; |
377 | r = d * w * 3 / 7; |
378 | |
379 | /* |
380 | * Place the points. |
381 | */ |
382 | for (i = 0; i < n; i++) { |
383 | double angle = i * 2 * PI / n; |
384 | double x = r * sin(angle), y = - r * cos(angle); |
42159ec6 |
385 | pts[i].x = (long)(c + x + 0.5); |
386 | pts[i].y = (long)(c + y + 0.5); |
9d6c3859 |
387 | pts[i].d = d; |
388 | } |
389 | } |
390 | |
391 | static char *new_game_desc(game_params *params, random_state *rs, |
392 | char **aux, int interactive) |
393 | { |
42159ec6 |
394 | int n = params->n, i; |
395 | long w, h, j, k, m; |
9d6c3859 |
396 | point *pts, *pts2; |
42159ec6 |
397 | long *tmp; |
9d6c3859 |
398 | tree234 *edges, *vertices; |
399 | edge *e, *e2; |
400 | vertex *v, *vs, *vlist; |
401 | char *ret; |
402 | |
403 | w = h = COORDLIMIT(n); |
404 | |
405 | /* |
406 | * Choose n points from this grid. |
407 | */ |
408 | pts = snewn(n, point); |
42159ec6 |
409 | tmp = snewn(w*h, long); |
9d6c3859 |
410 | for (i = 0; i < w*h; i++) |
411 | tmp[i] = i; |
412 | shuffle(tmp, w*h, sizeof(*tmp), rs); |
413 | for (i = 0; i < n; i++) { |
414 | pts[i].x = tmp[i] % w; |
415 | pts[i].y = tmp[i] / w; |
416 | pts[i].d = 1; |
417 | } |
418 | sfree(tmp); |
419 | |
420 | /* |
421 | * Now start adding edges between the points. |
422 | * |
423 | * At all times, we attempt to add an edge to the lowest-degree |
424 | * vertex we currently have, and we try the other vertices as |
425 | * candidate second endpoints in order of distance from this |
426 | * one. We stop as soon as we find an edge which |
427 | * |
428 | * (a) does not increase any vertex's degree beyond MAXDEGREE |
429 | * (b) does not cross any existing edges |
430 | * (c) does not intersect any actual point. |
431 | */ |
432 | vs = snewn(n, vertex); |
433 | vertices = newtree234(vertcmp); |
434 | for (i = 0; i < n; i++) { |
435 | v = vs + i; |
436 | v->param = 0; /* in this tree, param is the degree */ |
437 | v->vindex = i; |
438 | add234(vertices, v); |
439 | } |
440 | edges = newtree234(edgecmp); |
441 | vlist = snewn(n, vertex); |
442 | while (1) { |
443 | int added = FALSE; |
444 | |
445 | for (i = 0; i < n; i++) { |
446 | v = index234(vertices, i); |
447 | j = v->vindex; |
448 | |
449 | if (v->param >= MAXDEGREE) |
450 | break; /* nothing left to add! */ |
451 | |
452 | /* |
453 | * Sort the other vertices into order of their distance |
454 | * from this one. Don't bother looking below i, because |
455 | * we've already tried those edges the other way round. |
456 | * Also here we rule out target vertices with too high |
457 | * a degree, and (of course) ones to which we already |
458 | * have an edge. |
459 | */ |
460 | m = 0; |
461 | for (k = i+1; k < n; k++) { |
462 | vertex *kv = index234(vertices, k); |
463 | int ki = kv->vindex; |
464 | int dx, dy; |
465 | |
466 | if (kv->param >= MAXDEGREE || isedge(edges, ki, j)) |
467 | continue; |
468 | |
469 | vlist[m].vindex = ki; |
470 | dx = pts[ki].x - pts[j].x; |
471 | dy = pts[ki].y - pts[j].y; |
472 | vlist[m].param = dx*dx + dy*dy; |
473 | m++; |
474 | } |
475 | |
476 | qsort(vlist, m, sizeof(*vlist), vertcmpC); |
477 | |
478 | for (k = 0; k < m; k++) { |
479 | int p; |
480 | int ki = vlist[k].vindex; |
481 | |
482 | /* |
483 | * Check to see whether this edge intersects any |
484 | * existing edge or point. |
485 | */ |
486 | for (p = 0; p < n; p++) |
487 | if (p != ki && p != j && cross(pts[ki], pts[j], |
488 | pts[p], pts[p])) |
489 | break; |
490 | if (p < n) |
491 | continue; |
492 | for (p = 0; (e = index234(edges, p)) != NULL; p++) |
493 | if (e->a != ki && e->a != j && |
494 | e->b != ki && e->b != j && |
495 | cross(pts[ki], pts[j], pts[e->a], pts[e->b])) |
496 | break; |
497 | if (e) |
498 | continue; |
499 | |
500 | /* |
501 | * We're done! Add this edge, modify the degrees of |
502 | * the two vertices involved, and break. |
503 | */ |
504 | addedge(edges, j, ki); |
505 | added = TRUE; |
506 | del234(vertices, vs+j); |
507 | vs[j].param++; |
508 | add234(vertices, vs+j); |
509 | del234(vertices, vs+ki); |
510 | vs[ki].param++; |
511 | add234(vertices, vs+ki); |
512 | break; |
513 | } |
514 | |
515 | if (k < m) |
516 | break; |
517 | } |
518 | |
519 | if (!added) |
520 | break; /* we're done. */ |
521 | } |
522 | |
523 | /* |
524 | * That's our graph. Now shuffle the points, making sure that |
525 | * they come out with at least one crossed line when arranged |
526 | * in a circle (so that the puzzle isn't immediately solved!). |
527 | */ |
42159ec6 |
528 | tmp = snewn(n, long); |
9d6c3859 |
529 | for (i = 0; i < n; i++) |
530 | tmp[i] = i; |
531 | pts2 = snewn(n, point); |
532 | make_circle(pts2, n, w); |
533 | while (1) { |
534 | shuffle(tmp, n, sizeof(*tmp), rs); |
535 | for (i = 0; (e = index234(edges, i)) != NULL; i++) { |
536 | for (j = i+1; (e2 = index234(edges, j)) != NULL; j++) { |
537 | if (e2->a == e->a || e2->a == e->b || |
538 | e2->b == e->a || e2->b == e->b) |
539 | continue; |
540 | if (cross(pts2[tmp[e2->a]], pts2[tmp[e2->b]], |
541 | pts2[tmp[e->a]], pts2[tmp[e->b]])) |
542 | break; |
543 | } |
544 | if (e2) |
545 | break; |
546 | } |
547 | if (e) |
548 | break; /* we've found a crossing */ |
549 | } |
550 | |
551 | /* |
552 | * We're done. Now encode the graph in a string format. Let's |
553 | * use a comma-separated list of dash-separated vertex number |
554 | * pairs, numbered from zero. We'll sort the list to prevent |
555 | * side channels. |
556 | */ |
557 | ret = NULL; |
558 | { |
559 | char *sep; |
560 | char buf[80]; |
561 | int retlen; |
562 | edge *ea; |
563 | |
564 | retlen = 0; |
565 | m = count234(edges); |
566 | ea = snewn(m, edge); |
567 | for (i = 0; (e = index234(edges, i)) != NULL; i++) { |
568 | assert(i < m); |
569 | ea[i].a = min(tmp[e->a], tmp[e->b]); |
570 | ea[i].b = max(tmp[e->a], tmp[e->b]); |
571 | retlen += 1 + sprintf(buf, "%d-%d", ea[i].a, ea[i].b); |
572 | } |
573 | assert(i == m); |
574 | qsort(ea, m, sizeof(*ea), edgecmpC); |
575 | |
576 | ret = snewn(retlen, char); |
577 | sep = ""; |
578 | k = 0; |
579 | |
580 | for (i = 0; i < m; i++) { |
581 | k += sprintf(ret + k, "%s%d-%d", sep, ea[i].a, ea[i].b); |
582 | sep = ","; |
583 | } |
584 | assert(k < retlen); |
585 | |
586 | sfree(ea); |
587 | } |
588 | |
589 | /* |
590 | * Encode the solution we started with as an aux_info string. |
591 | */ |
592 | { |
593 | char buf[80]; |
594 | char *auxstr; |
595 | int auxlen; |
596 | |
597 | auxlen = 2; /* leading 'S' and trailing '\0' */ |
598 | for (i = 0; i < n; i++) { |
599 | j = tmp[i]; |
600 | pts2[j] = pts[i]; |
601 | if (pts2[j].d & 1) { |
602 | pts2[j].x *= 2; |
603 | pts2[j].y *= 2; |
604 | pts2[j].d *= 2; |
605 | } |
606 | pts2[j].x += pts2[j].d / 2; |
607 | pts2[j].y += pts2[j].d / 2; |
42159ec6 |
608 | auxlen += sprintf(buf, ";P%d:%ld,%ld/%ld", i, |
9d6c3859 |
609 | pts2[j].x, pts2[j].y, pts2[j].d); |
610 | } |
611 | k = 0; |
612 | auxstr = snewn(auxlen, char); |
613 | auxstr[k++] = 'S'; |
614 | for (i = 0; i < n; i++) |
42159ec6 |
615 | k += sprintf(auxstr+k, ";P%d:%ld,%ld/%ld", i, |
9d6c3859 |
616 | pts2[i].x, pts2[i].y, pts2[i].d); |
617 | assert(k < auxlen); |
618 | *aux = auxstr; |
619 | } |
620 | sfree(pts2); |
621 | |
622 | sfree(tmp); |
623 | sfree(vlist); |
624 | freetree234(vertices); |
625 | sfree(vs); |
626 | while ((e = delpos234(edges, 0)) != NULL) |
627 | sfree(e); |
628 | freetree234(edges); |
629 | sfree(pts); |
630 | |
631 | return ret; |
632 | } |
633 | |
634 | static char *validate_desc(game_params *params, char *desc) |
635 | { |
636 | int a, b; |
637 | |
638 | while (*desc) { |
639 | a = atoi(desc); |
640 | if (a < 0 || a >= params->n) |
641 | return "Number out of range in game description"; |
642 | while (*desc && isdigit((unsigned char)*desc)) desc++; |
643 | if (*desc != '-') |
644 | return "Expected '-' after number in game description"; |
645 | desc++; /* eat dash */ |
646 | b = atoi(desc); |
647 | if (b < 0 || b >= params->n) |
648 | return "Number out of range in game description"; |
649 | while (*desc && isdigit((unsigned char)*desc)) desc++; |
650 | if (*desc) { |
651 | if (*desc != ',') |
652 | return "Expected ',' after number in game description"; |
653 | desc++; /* eat comma */ |
654 | } |
655 | } |
656 | |
657 | return NULL; |
658 | } |
659 | |
660 | static game_state *new_game(midend_data *me, game_params *params, char *desc) |
661 | { |
662 | int n = params->n; |
663 | game_state *state = snew(game_state); |
664 | int a, b; |
665 | |
666 | state->params = *params; |
667 | state->w = state->h = COORDLIMIT(n); |
668 | state->pts = snewn(n, point); |
669 | make_circle(state->pts, n, state->w); |
670 | state->graph = snew(struct graph); |
671 | state->graph->refcount = 1; |
672 | state->graph->edges = newtree234(edgecmp); |
673 | state->completed = state->cheated = state->just_solved = FALSE; |
674 | |
675 | while (*desc) { |
676 | a = atoi(desc); |
677 | assert(a >= 0 && a < params->n); |
678 | while (*desc && isdigit((unsigned char)*desc)) desc++; |
679 | assert(*desc == '-'); |
680 | desc++; /* eat dash */ |
681 | b = atoi(desc); |
682 | assert(b >= 0 && b < params->n); |
683 | while (*desc && isdigit((unsigned char)*desc)) desc++; |
684 | if (*desc) { |
685 | assert(*desc == ','); |
686 | desc++; /* eat comma */ |
687 | } |
688 | addedge(state->graph->edges, a, b); |
689 | } |
690 | |
691 | return state; |
692 | } |
693 | |
694 | static game_state *dup_game(game_state *state) |
695 | { |
696 | int n = state->params.n; |
697 | game_state *ret = snew(game_state); |
698 | |
699 | ret->params = state->params; |
700 | ret->w = state->w; |
701 | ret->h = state->h; |
702 | ret->pts = snewn(n, point); |
703 | memcpy(ret->pts, state->pts, n * sizeof(point)); |
704 | ret->graph = state->graph; |
705 | ret->graph->refcount++; |
706 | ret->completed = state->completed; |
707 | ret->cheated = state->cheated; |
708 | ret->just_solved = state->just_solved; |
709 | |
710 | return ret; |
711 | } |
712 | |
713 | static void free_game(game_state *state) |
714 | { |
715 | if (--state->graph->refcount <= 0) { |
716 | edge *e; |
717 | while ((e = delpos234(state->graph->edges, 0)) != NULL) |
718 | sfree(e); |
719 | freetree234(state->graph->edges); |
720 | sfree(state->graph); |
721 | } |
722 | sfree(state->pts); |
723 | sfree(state); |
724 | } |
725 | |
726 | static char *solve_game(game_state *state, game_state *currstate, |
727 | char *aux, char **error) |
728 | { |
886119cd |
729 | int n = state->params.n; |
730 | int matrix[4]; |
731 | point *pts; |
732 | int i, j, besti; |
733 | float bestd; |
734 | char buf[80], *ret; |
735 | int retlen, retsize; |
736 | |
9d6c3859 |
737 | if (!aux) { |
738 | *error = "Solution not known for this puzzle"; |
739 | return NULL; |
740 | } |
741 | |
886119cd |
742 | /* |
743 | * Decode the aux_info to get the original point positions. |
744 | */ |
745 | pts = snewn(n, point); |
746 | aux++; /* eat 'S' */ |
747 | for (i = 0; i < n; i++) { |
748 | int p, k; |
749 | long x, y, d; |
750 | int ret = sscanf(aux, ";P%d:%ld,%ld/%ld%n", &p, &x, &y, &d, &k); |
751 | if (ret != 4 || p != i) { |
752 | *error = "Internal error: aux_info badly formatted"; |
753 | sfree(pts); |
754 | return NULL; |
755 | } |
756 | pts[i].x = x; |
757 | pts[i].y = y; |
758 | pts[i].d = d; |
759 | aux += k; |
760 | } |
761 | |
762 | /* |
763 | * Now go through eight possible symmetries of the point set. |
764 | * For each one, work out the sum of the Euclidean distances |
765 | * between the points' current positions and their new ones. |
766 | * |
767 | * We're squaring distances here, which means we're at risk of |
768 | * integer overflow. Fortunately, there's no real need to be |
769 | * massively careful about rounding errors, since this is a |
770 | * non-essential bit of the code; so I'll just work in floats |
771 | * internally. |
772 | */ |
773 | besti = -1; |
774 | bestd = 0.0F; |
775 | |
776 | for (i = 0; i < 8; i++) { |
777 | float d; |
778 | |
779 | matrix[0] = matrix[1] = matrix[2] = matrix[3] = 0; |
780 | matrix[i & 1] = (i & 2) ? +1 : -1; |
781 | matrix[3-(i&1)] = (i & 4) ? +1 : -1; |
782 | |
783 | d = 0.0F; |
784 | for (j = 0; j < n; j++) { |
785 | float px = (float)pts[j].x / pts[j].d; |
786 | float py = (float)pts[j].y / pts[j].d; |
787 | float sx = (float)currstate->pts[j].x / currstate->pts[j].d; |
788 | float sy = (float)currstate->pts[j].y / currstate->pts[j].d; |
789 | float cx = (float)currstate->w / 2; |
790 | float cy = (float)currstate->h / 2; |
791 | float ox, oy, dx, dy; |
792 | |
793 | px -= cx; |
794 | py -= cy; |
795 | |
796 | ox = matrix[0] * px + matrix[1] * py; |
797 | oy = matrix[2] * px + matrix[3] * py; |
798 | |
799 | ox += cx; |
800 | oy += cy; |
801 | |
802 | dx = ox - sx; |
803 | dy = oy - sy; |
804 | |
805 | d += dx*dx + dy*dy; |
806 | } |
807 | |
808 | if (besti < 0 || bestd > d) { |
809 | besti = i; |
810 | bestd = d; |
811 | } |
812 | } |
813 | |
814 | assert(besti >= 0); |
815 | |
816 | /* |
817 | * Now we know which symmetry is closest to the points' current |
818 | * positions. Use it. |
819 | */ |
820 | matrix[0] = matrix[1] = matrix[2] = matrix[3] = 0; |
821 | matrix[besti & 1] = (besti & 2) ? +1 : -1; |
822 | matrix[3-(besti&1)] = (besti & 4) ? +1 : -1; |
823 | |
824 | retsize = 256; |
825 | ret = snewn(retsize, char); |
826 | retlen = 0; |
827 | ret[retlen++] = 'S'; |
828 | ret[retlen] = '\0'; |
829 | |
830 | for (i = 0; i < n; i++) { |
831 | float px = (float)pts[i].x / pts[i].d; |
832 | float py = (float)pts[i].y / pts[i].d; |
833 | float cx = (float)currstate->w / 2; |
834 | float cy = (float)currstate->h / 2; |
835 | float ox, oy; |
836 | int extra; |
837 | |
838 | px -= cx; |
839 | py -= cy; |
840 | |
841 | ox = matrix[0] * px + matrix[1] * py; |
842 | oy = matrix[2] * px + matrix[3] * py; |
843 | |
844 | ox += cx; |
845 | oy += cy; |
846 | |
847 | /* |
848 | * Use a fixed denominator of 2, because we know the |
849 | * original points were on an integer grid offset by 1/2. |
850 | */ |
851 | pts[i].d = 2; |
852 | ox *= pts[i].d; |
853 | oy *= pts[i].d; |
854 | pts[i].x = ox + 0.5; |
855 | pts[i].y = oy + 0.5; |
856 | |
857 | extra = sprintf(buf, ";P%d:%ld,%ld/%ld", i, |
858 | pts[i].x, pts[i].y, pts[i].d); |
859 | if (retlen + extra >= retsize) { |
860 | retsize = retlen + extra + 256; |
861 | ret = sresize(ret, retsize, char); |
862 | } |
863 | strcpy(ret + retlen, buf); |
864 | retlen += extra; |
865 | } |
866 | |
867 | sfree(pts); |
868 | |
869 | return ret; |
9d6c3859 |
870 | } |
871 | |
872 | static char *game_text_format(game_state *state) |
873 | { |
874 | return NULL; |
875 | } |
876 | |
877 | struct game_ui { |
878 | int dragpoint; /* point being dragged; -1 if none */ |
879 | point newpoint; /* where it's been dragged to so far */ |
880 | int just_dragged; /* reset in game_changed_state */ |
881 | int just_moved; /* _set_ in game_changed_state */ |
882 | float anim_length; |
883 | }; |
884 | |
885 | static game_ui *new_ui(game_state *state) |
886 | { |
887 | game_ui *ui = snew(game_ui); |
888 | ui->dragpoint = -1; |
889 | ui->just_moved = ui->just_dragged = FALSE; |
890 | return ui; |
891 | } |
892 | |
893 | static void free_ui(game_ui *ui) |
894 | { |
895 | sfree(ui); |
896 | } |
897 | |
898 | static char *encode_ui(game_ui *ui) |
899 | { |
900 | return NULL; |
901 | } |
902 | |
903 | static void decode_ui(game_ui *ui, char *encoding) |
904 | { |
905 | } |
906 | |
907 | static void game_changed_state(game_ui *ui, game_state *oldstate, |
908 | game_state *newstate) |
909 | { |
910 | ui->dragpoint = -1; |
911 | ui->just_moved = ui->just_dragged; |
912 | ui->just_dragged = FALSE; |
913 | } |
914 | |
915 | struct game_drawstate { |
42159ec6 |
916 | long tilesize; |
9d6c3859 |
917 | }; |
918 | |
919 | static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds, |
920 | int x, int y, int button) |
921 | { |
922 | int n = state->params.n; |
923 | |
924 | if (button == LEFT_BUTTON) { |
42159ec6 |
925 | int i, best; |
926 | long bestd; |
9d6c3859 |
927 | |
928 | /* |
929 | * Begin drag. We drag the vertex _nearest_ to the pointer, |
930 | * just in case one is nearly on top of another and we want |
931 | * to drag the latter. However, we drag nothing at all if |
932 | * the nearest vertex is outside DRAG_THRESHOLD. |
933 | */ |
934 | best = -1; |
935 | bestd = 0; |
936 | |
937 | for (i = 0; i < n; i++) { |
42159ec6 |
938 | long px = state->pts[i].x * ds->tilesize / state->pts[i].d; |
939 | long py = state->pts[i].y * ds->tilesize / state->pts[i].d; |
940 | long dx = px - x; |
941 | long dy = py - y; |
942 | long d = dx*dx + dy*dy; |
9d6c3859 |
943 | |
944 | if (best == -1 || bestd > d) { |
945 | best = i; |
946 | bestd = d; |
947 | } |
948 | } |
949 | |
950 | if (bestd <= DRAG_THRESHOLD * DRAG_THRESHOLD) { |
951 | ui->dragpoint = best; |
952 | ui->newpoint.x = x; |
953 | ui->newpoint.y = y; |
954 | ui->newpoint.d = ds->tilesize; |
955 | return ""; |
956 | } |
957 | |
958 | } else if (button == LEFT_DRAG && ui->dragpoint >= 0) { |
959 | ui->newpoint.x = x; |
960 | ui->newpoint.y = y; |
961 | ui->newpoint.d = ds->tilesize; |
962 | return ""; |
963 | } else if (button == LEFT_RELEASE && ui->dragpoint >= 0) { |
964 | int p = ui->dragpoint; |
965 | char buf[80]; |
966 | |
967 | ui->dragpoint = -1; /* terminate drag, no matter what */ |
968 | |
969 | /* |
970 | * First, see if we're within range. The user can cancel a |
971 | * drag by dragging the point right off the window. |
972 | */ |
42159ec6 |
973 | if (ui->newpoint.x < 0 || |
974 | ui->newpoint.x >= (long)state->w*ui->newpoint.d || |
975 | ui->newpoint.y < 0 || |
976 | ui->newpoint.y >= (long)state->h*ui->newpoint.d) |
9d6c3859 |
977 | return ""; |
978 | |
979 | /* |
980 | * We aren't cancelling the drag. Construct a move string |
981 | * indicating where this point is going to. |
982 | */ |
42159ec6 |
983 | sprintf(buf, "P%d:%ld,%ld/%ld", p, |
9d6c3859 |
984 | ui->newpoint.x, ui->newpoint.y, ui->newpoint.d); |
985 | ui->just_dragged = TRUE; |
986 | return dupstr(buf); |
987 | } |
988 | |
989 | return NULL; |
990 | } |
991 | |
992 | static game_state *execute_move(game_state *state, char *move) |
993 | { |
994 | int n = state->params.n; |
42159ec6 |
995 | int p, k; |
996 | long x, y, d; |
9d6c3859 |
997 | game_state *ret = dup_game(state); |
998 | |
999 | ret->just_solved = FALSE; |
1000 | |
1001 | while (*move) { |
1002 | if (*move == 'S') { |
1003 | move++; |
1004 | if (*move == ';') move++; |
1005 | ret->cheated = ret->just_solved = TRUE; |
1006 | } |
1007 | if (*move == 'P' && |
42159ec6 |
1008 | sscanf(move+1, "%d:%ld,%ld/%ld%n", &p, &x, &y, &d, &k) == 4 && |
9d6c3859 |
1009 | p >= 0 && p < n && d > 0) { |
1010 | ret->pts[p].x = x; |
1011 | ret->pts[p].y = y; |
1012 | ret->pts[p].d = d; |
1013 | |
1014 | move += k+1; |
1015 | if (*move == ';') move++; |
1016 | } else { |
1017 | free_game(ret); |
1018 | return NULL; |
1019 | } |
1020 | } |
1021 | |
1022 | /* |
1023 | * Check correctness: for every pair of edges, see whether they |
1024 | * cross. |
1025 | */ |
1026 | if (!ret->completed) { |
1027 | int i, j; |
1028 | edge *e, *e2; |
1029 | |
1030 | for (i = 0; (e = index234(ret->graph->edges, i)) != NULL; i++) { |
1031 | for (j = i+1; (e2 = index234(ret->graph->edges, j)) != NULL; j++) { |
1032 | if (e2->a == e->a || e2->a == e->b || |
1033 | e2->b == e->a || e2->b == e->b) |
1034 | continue; |
1035 | if (cross(ret->pts[e2->a], ret->pts[e2->b], |
1036 | ret->pts[e->a], ret->pts[e->b])) |
1037 | break; |
1038 | } |
1039 | if (e2) |
1040 | break; |
1041 | } |
1042 | |
1043 | /* |
1044 | * e == NULL if we've gone through all the edge pairs |
1045 | * without finding a crossing. |
1046 | */ |
1047 | ret->completed = (e == NULL); |
1048 | } |
1049 | |
1050 | return ret; |
1051 | } |
1052 | |
1053 | /* ---------------------------------------------------------------------- |
1054 | * Drawing routines. |
1055 | */ |
1056 | |
1057 | static void game_compute_size(game_params *params, int tilesize, |
1058 | int *x, int *y) |
1059 | { |
1060 | *x = *y = COORDLIMIT(params->n) * tilesize; |
1061 | } |
1062 | |
1063 | static void game_set_size(game_drawstate *ds, game_params *params, |
1064 | int tilesize) |
1065 | { |
1066 | ds->tilesize = tilesize; |
1067 | } |
1068 | |
1069 | static float *game_colours(frontend *fe, game_state *state, int *ncolours) |
1070 | { |
1071 | float *ret = snewn(3 * NCOLOURS, float); |
1072 | |
1073 | frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]); |
1074 | |
1075 | ret[COL_LINE * 3 + 0] = 0.0F; |
1076 | ret[COL_LINE * 3 + 1] = 0.0F; |
1077 | ret[COL_LINE * 3 + 2] = 0.0F; |
1078 | |
1079 | ret[COL_OUTLINE * 3 + 0] = 0.0F; |
1080 | ret[COL_OUTLINE * 3 + 1] = 0.0F; |
1081 | ret[COL_OUTLINE * 3 + 2] = 0.0F; |
1082 | |
1083 | ret[COL_POINT * 3 + 0] = 0.0F; |
1084 | ret[COL_POINT * 3 + 1] = 0.0F; |
1085 | ret[COL_POINT * 3 + 2] = 1.0F; |
1086 | |
1087 | ret[COL_DRAGPOINT * 3 + 0] = 1.0F; |
1088 | ret[COL_DRAGPOINT * 3 + 1] = 1.0F; |
1089 | ret[COL_DRAGPOINT * 3 + 2] = 1.0F; |
1090 | |
1091 | ret[COL_NEIGHBOUR * 3 + 0] = 1.0F; |
1092 | ret[COL_NEIGHBOUR * 3 + 1] = 0.0F; |
1093 | ret[COL_NEIGHBOUR * 3 + 2] = 0.0F; |
1094 | |
8eef6b92 |
1095 | ret[COL_FLASH1 * 3 + 0] = 0.5F; |
1096 | ret[COL_FLASH1 * 3 + 1] = 0.5F; |
1097 | ret[COL_FLASH1 * 3 + 2] = 0.5F; |
1098 | |
1099 | ret[COL_FLASH2 * 3 + 0] = 1.0F; |
1100 | ret[COL_FLASH2 * 3 + 1] = 1.0F; |
1101 | ret[COL_FLASH2 * 3 + 2] = 1.0F; |
1102 | |
9d6c3859 |
1103 | *ncolours = NCOLOURS; |
1104 | return ret; |
1105 | } |
1106 | |
1107 | static game_drawstate *game_new_drawstate(game_state *state) |
1108 | { |
1109 | struct game_drawstate *ds = snew(struct game_drawstate); |
1110 | |
1111 | ds->tilesize = 0; |
1112 | |
1113 | return ds; |
1114 | } |
1115 | |
1116 | static void game_free_drawstate(game_drawstate *ds) |
1117 | { |
1118 | sfree(ds); |
1119 | } |
1120 | |
1121 | static point mix(point a, point b, float distance) |
1122 | { |
1123 | point ret; |
1124 | |
1125 | ret.d = a.d * b.d; |
1126 | ret.x = a.x * b.d + distance * (b.x * a.d - a.x * b.d); |
1127 | ret.y = a.y * b.d + distance * (b.y * a.d - a.y * b.d); |
1128 | |
1129 | return ret; |
1130 | } |
1131 | |
1132 | static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate, |
1133 | game_state *state, int dir, game_ui *ui, |
1134 | float animtime, float flashtime) |
1135 | { |
1136 | int w, h; |
1137 | edge *e; |
1138 | int i, j; |
1139 | int bg; |
1140 | |
1141 | /* |
1142 | * There's no terribly sensible way to do partial redraws of |
1143 | * this game, so I'm going to have to resort to redrawing the |
1144 | * whole thing every time. |
1145 | */ |
1146 | |
8eef6b92 |
1147 | if (flashtime == 0) |
1148 | bg = COL_BACKGROUND; |
1149 | else if ((int)(flashtime * 4 / FLASH_TIME) % 2 == 0) |
1150 | bg = COL_FLASH1; |
1151 | else |
1152 | bg = COL_FLASH2; |
1153 | |
9d6c3859 |
1154 | game_compute_size(&state->params, ds->tilesize, &w, &h); |
1155 | draw_rect(fe, 0, 0, w, h, bg); |
1156 | |
1157 | /* |
1158 | * Draw the edges. |
1159 | */ |
1160 | |
1161 | for (i = 0; (e = index234(state->graph->edges, i)) != NULL; i++) { |
1162 | point p1, p2; |
42159ec6 |
1163 | long x1, y1, x2, y2; |
9d6c3859 |
1164 | |
1165 | p1 = state->pts[e->a]; |
1166 | p2 = state->pts[e->b]; |
1167 | if (ui->dragpoint == e->a) |
1168 | p1 = ui->newpoint; |
1169 | else if (ui->dragpoint == e->b) |
1170 | p2 = ui->newpoint; |
1171 | |
1172 | if (oldstate) { |
1173 | p1 = mix(oldstate->pts[e->a], p1, animtime / ui->anim_length); |
1174 | p2 = mix(oldstate->pts[e->b], p2, animtime / ui->anim_length); |
1175 | } |
1176 | |
1177 | x1 = p1.x * ds->tilesize / p1.d; |
1178 | y1 = p1.y * ds->tilesize / p1.d; |
1179 | x2 = p2.x * ds->tilesize / p2.d; |
1180 | y2 = p2.y * ds->tilesize / p2.d; |
1181 | |
1182 | draw_line(fe, x1, y1, x2, y2, COL_LINE); |
1183 | } |
1184 | |
1185 | /* |
1186 | * Draw the points. |
1187 | * |
1188 | * When dragging, we should not only vary the colours, but |
1189 | * leave the point being dragged until last. |
1190 | */ |
1191 | for (j = 0; j < 3; j++) { |
1192 | int thisc = (j == 0 ? COL_POINT : |
1193 | j == 1 ? COL_NEIGHBOUR : COL_DRAGPOINT); |
1194 | for (i = 0; i < state->params.n; i++) { |
42159ec6 |
1195 | long x, y; |
1196 | int c; |
9d6c3859 |
1197 | point p = state->pts[i]; |
1198 | |
1199 | if (ui->dragpoint == i) { |
1200 | p = ui->newpoint; |
1201 | c = COL_DRAGPOINT; |
1202 | } else if (ui->dragpoint >= 0 && |
1203 | isedge(state->graph->edges, ui->dragpoint, i)) { |
1204 | c = COL_NEIGHBOUR; |
1205 | } else { |
1206 | c = COL_POINT; |
1207 | } |
1208 | |
1209 | if (oldstate) |
1210 | p = mix(oldstate->pts[i], p, animtime / ui->anim_length); |
1211 | |
1212 | if (c == thisc) { |
1213 | x = p.x * ds->tilesize / p.d; |
1214 | y = p.y * ds->tilesize / p.d; |
1215 | |
1216 | #ifdef VERTEX_NUMBERS |
1217 | draw_circle(fe, x, y, DRAG_THRESHOLD, bg, bg); |
1218 | { |
1219 | char buf[80]; |
1220 | sprintf(buf, "%d", i); |
1221 | draw_text(fe, x, y, FONT_VARIABLE, DRAG_THRESHOLD*3/2, |
1222 | ALIGN_VCENTRE|ALIGN_HCENTRE, c, buf); |
1223 | } |
1224 | #else |
1225 | draw_circle(fe, x, y, CIRCLE_RADIUS, c, COL_OUTLINE); |
1226 | #endif |
1227 | } |
1228 | } |
1229 | } |
1230 | |
1231 | draw_update(fe, 0, 0, w, h); |
1232 | } |
1233 | |
1234 | static float game_anim_length(game_state *oldstate, game_state *newstate, |
1235 | int dir, game_ui *ui) |
1236 | { |
1237 | if (ui->just_moved) |
1238 | return 0.0F; |
1239 | if ((dir < 0 ? oldstate : newstate)->just_solved) |
1240 | ui->anim_length = SOLVEANIM_TIME; |
1241 | else |
1242 | ui->anim_length = ANIM_TIME; |
1243 | return ui->anim_length; |
1244 | } |
1245 | |
1246 | static float game_flash_length(game_state *oldstate, game_state *newstate, |
1247 | int dir, game_ui *ui) |
1248 | { |
1249 | if (!oldstate->completed && newstate->completed && |
1250 | !oldstate->cheated && !newstate->cheated) |
1251 | return FLASH_TIME; |
1252 | return 0.0F; |
1253 | } |
1254 | |
1255 | static int game_wants_statusbar(void) |
1256 | { |
1257 | return FALSE; |
1258 | } |
1259 | |
1260 | static int game_timing_state(game_state *state, game_ui *ui) |
1261 | { |
1262 | return TRUE; |
1263 | } |
1264 | |
1265 | #ifdef COMBINED |
1266 | #define thegame untangle |
1267 | #endif |
1268 | |
1269 | const struct game thegame = { |
1270 | "Untangle", "games.untangle", |
1271 | default_params, |
1272 | game_fetch_preset, |
1273 | decode_params, |
1274 | encode_params, |
1275 | free_params, |
1276 | dup_params, |
1277 | TRUE, game_configure, custom_params, |
1278 | validate_params, |
1279 | new_game_desc, |
1280 | validate_desc, |
1281 | new_game, |
1282 | dup_game, |
1283 | free_game, |
1284 | TRUE, solve_game, |
1285 | FALSE, game_text_format, |
1286 | new_ui, |
1287 | free_ui, |
1288 | encode_ui, |
1289 | decode_ui, |
1290 | game_changed_state, |
1291 | interpret_move, |
1292 | execute_move, |
1293 | PREFERRED_TILESIZE, game_compute_size, game_set_size, |
1294 | game_colours, |
1295 | game_new_drawstate, |
1296 | game_free_drawstate, |
1297 | game_redraw, |
1298 | game_anim_length, |
1299 | game_flash_length, |
1300 | game_wants_statusbar, |
1301 | FALSE, game_timing_state, |
1302 | SOLVE_ANIMATES, /* mouse_priorities */ |
1303 | }; |