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 | |
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; |
1ad942e7 |
287 | b = 1L << 30; /* largest available power of 4 */ |
9d6c3859 |
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 | }; |