15 #define PI 3.141592653589793238462643383279502884197169399
17 #define MATMUL(xr,yr,m,x,y) do { \
18 float rx, ry, xx = (x), yy = (y), *mat = (m); \
19 rx = mat[0] * xx + mat[2] * yy; \
20 ry = mat[1] * xx + mat[3] * yy; \
21 (xr) = rx; (yr) = ry; \
24 /* Direction and other bitfields */
31 /* Corner flags go in the barriers array */
37 /* Rotations: Anticlockwise, Clockwise, Flip, general rotate */
38 #define A(x) ( (((x) & 0x07) << 1) | (((x) & 0x08) >> 3) )
39 #define C(x) ( (((x) & 0x0E) >> 1) | (((x) & 0x01) << 3) )
40 #define F(x) ( (((x) & 0x0C) >> 2) | (((x) & 0x03) << 2) )
41 #define ROT(x, n) ( ((n)&3) == 0 ? (x) : \
42 ((n)&3) == 1 ? A(x) : \
43 ((n)&3) == 2 ? F(x) : C(x) )
45 /* X and Y displacements */
46 #define X(x) ( (x) == R ? +1 : (x) == L ? -1 : 0 )
47 #define Y(x) ( (x) == D ? +1 : (x) == U ? -1 : 0 )
50 #define COUNT(x) ( (((x) & 0x08) >> 3) + (((x) & 0x04) >> 2) + \
51 (((x) & 0x02) >> 1) + ((x) & 0x01) )
55 #define WINDOW_OFFSET 16
57 #define ROTATE_TIME 0.13F
58 #define FLASH_FRAME 0.07F
76 float barrier_probability;
79 struct game_aux_info {
85 int width, height, cx, cy, wrapping, completed;
86 int last_rotate_x, last_rotate_y, last_rotate_dir;
87 int used_solve, just_used_solve;
89 unsigned char *barriers;
92 #define OFFSETWH(x2,y2,x1,y1,dir,width,height) \
93 ( (x2) = ((x1) + width + X((dir))) % width, \
94 (y2) = ((y1) + height + Y((dir))) % height)
96 #define OFFSET(x2,y2,x1,y1,dir,state) \
97 OFFSETWH(x2,y2,x1,y1,dir,(state)->width,(state)->height)
99 #define index(state, a, x, y) ( a[(y) * (state)->width + (x)] )
100 #define tile(state, x, y) index(state, (state)->tiles, x, y)
101 #define barrier(state, x, y) index(state, (state)->barriers, x, y)
107 static int xyd_cmp(const void *av, const void *bv) {
108 const struct xyd *a = (const struct xyd *)av;
109 const struct xyd *b = (const struct xyd *)bv;
118 if (a->direction < b->direction)
120 if (a->direction > b->direction)
125 static int xyd_cmp_nc(void *av, void *bv) { return xyd_cmp(av, bv); }
127 static struct xyd *new_xyd(int x, int y, int direction)
129 struct xyd *xyd = snew(struct xyd);
132 xyd->direction = direction;
136 /* ----------------------------------------------------------------------
137 * Manage game parameters.
139 static game_params *default_params(void)
141 game_params *ret = snew(game_params);
145 ret->wrapping = FALSE;
147 ret->barrier_probability = 0.0;
152 static int game_fetch_preset(int i, char **name, game_params **params)
156 static const struct { int x, y, wrap; } values[] = {
169 if (i < 0 || i >= lenof(values))
172 ret = snew(game_params);
173 ret->width = values[i].x;
174 ret->height = values[i].y;
175 ret->wrapping = values[i].wrap;
177 ret->barrier_probability = 0.0;
179 sprintf(str, "%dx%d%s", ret->width, ret->height,
180 ret->wrapping ? " wrapping" : "");
187 static void free_params(game_params *params)
192 static game_params *dup_params(game_params *params)
194 game_params *ret = snew(game_params);
195 *ret = *params; /* structure copy */
199 static void decode_params(game_params *ret, char const *string)
201 char const *p = string;
203 ret->width = atoi(p);
204 while (*p && isdigit((unsigned char)*p)) p++;
207 ret->height = atoi(p);
208 while (*p && isdigit((unsigned char)*p)) p++;
210 ret->height = ret->width;
216 ret->wrapping = TRUE;
217 } else if (*p == 'b') {
219 ret->barrier_probability = atof(p);
220 while (*p && (*p == '.' || isdigit((unsigned char)*p))) p++;
221 } else if (*p == 'a') {
225 p++; /* skip any other gunk */
229 static char *encode_params(game_params *params, int full)
234 len = sprintf(ret, "%dx%d", params->width, params->height);
235 if (params->wrapping)
237 if (full && params->barrier_probability)
238 len += sprintf(ret+len, "b%g", params->barrier_probability);
239 if (full && !params->unique)
241 assert(len < lenof(ret));
247 static config_item *game_configure(game_params *params)
252 ret = snewn(6, config_item);
254 ret[0].name = "Width";
255 ret[0].type = C_STRING;
256 sprintf(buf, "%d", params->width);
257 ret[0].sval = dupstr(buf);
260 ret[1].name = "Height";
261 ret[1].type = C_STRING;
262 sprintf(buf, "%d", params->height);
263 ret[1].sval = dupstr(buf);
266 ret[2].name = "Walls wrap around";
267 ret[2].type = C_BOOLEAN;
269 ret[2].ival = params->wrapping;
271 ret[3].name = "Barrier probability";
272 ret[3].type = C_STRING;
273 sprintf(buf, "%g", params->barrier_probability);
274 ret[3].sval = dupstr(buf);
277 ret[4].name = "Ensure unique solution";
278 ret[4].type = C_BOOLEAN;
280 ret[4].ival = params->unique;
290 static game_params *custom_params(config_item *cfg)
292 game_params *ret = snew(game_params);
294 ret->width = atoi(cfg[0].sval);
295 ret->height = atoi(cfg[1].sval);
296 ret->wrapping = cfg[2].ival;
297 ret->barrier_probability = (float)atof(cfg[3].sval);
298 ret->unique = cfg[4].ival;
303 static char *validate_params(game_params *params)
305 if (params->width <= 0 && params->height <= 0)
306 return "Width and height must both be greater than zero";
307 if (params->width <= 0)
308 return "Width must be greater than zero";
309 if (params->height <= 0)
310 return "Height must be greater than zero";
311 if (params->width <= 1 && params->height <= 1)
312 return "At least one of width and height must be greater than one";
313 if (params->barrier_probability < 0)
314 return "Barrier probability may not be negative";
315 if (params->barrier_probability > 1)
316 return "Barrier probability may not be greater than 1";
320 /* ----------------------------------------------------------------------
321 * Solver used to assure solution uniqueness during generation.
325 * Test cases I used while debugging all this were
327 * ./net --generate 1 13x11w#12300
328 * which expands under the non-unique grid generation rules to
329 * 13x11w:5eaade1bd222664436d5e2965c12656b1129dd825219e3274d558d5eb2dab5da18898e571d5a2987be79746bd95726c597447d6da96188c513add829da7681da954db113d3cd244
330 * and has two ambiguous areas.
332 * An even better one is
333 * 13x11w#507896411361192
335 * 13x11w:b7125b1aec598eb31bd58d82572bc11494e5dee4e8db2bdd29b88d41a16bdd996d2996ddec8c83741a1e8674e78328ba71737b8894a9271b1cd1399453d1952e43951d9b712822e
336 * and has an ambiguous area _and_ a situation where loop avoidance
337 * is a necessary deductive technique.
340 * 48x25w#820543338195187
342 * 48x25w:255989d14cdd185deaa753a93821a12edc1ab97943ac127e2685d7b8b3c48861b2192416139212b316eddd35de43714ebc7628d753db32e596284d9ec52c5a7dc1b4c811a655117d16dc28921b2b4161352cab1d89d18bc836b8b891d55ea4622a1251861b5bc9a8aa3e5bcd745c95229ca6c3b5e21d5832d397e917325793d7eb442dc351b2db2a52ba8e1651642275842d8871d5534aabc6d5b741aaa2d48ed2a7dbbb3151ddb49d5b9a7ed1ab98ee75d613d656dbba347bc514c84556b43a9bc65a3256ead792488b862a9d2a8a39b4255a4949ed7dbd79443292521265896b4399c95ede89d7c8c797a6a57791a849adea489359a158aa12e5dacce862b8333b7ebea7d344d1a3c53198864b73a9dedde7b663abb1b539e1e8853b1b7edb14a2a17ebaae4dbe63598a2e7e9a2dbdad415bc1d8cb88cbab5a8c82925732cd282e641ea3bd7d2c6e776de9117a26be86deb7c82c89524b122cb9397cd1acd2284e744ea62b9279bae85479ababe315c3ac29c431333395b24e6a1e3c43a2da42d4dce84aadd5b154aea555eaddcbd6e527d228c19388d9b424d94214555a7edbdeebe569d4a56dc51a86bd9963e377bb74752bd5eaa5761ba545e297b62a1bda46ab4aee423ad6c661311783cc18786d4289236563cb4a75ec67d481c14814994464cd1b87396dee63e5ab6e952cc584baa1d4c47cb557ec84dbb63d487c8728118673a166846dd3a4ebc23d6cb9c5827d96b4556e91899db32b517eda815ae271a8911bd745447121dc8d321557bc2a435ebec1bbac35b1a291669451174e6aa2218a4a9c5a6ca31ebc45d84e3a82c121e9ced7d55e9a
343 * which has a spot (far right) where slightly more complex loop
344 * avoidance is required.
347 static int dsf_canonify(int *dsf, int val)
351 while (dsf[val] != val)
363 static void dsf_merge(int *dsf, int v1, int v2)
365 v1 = dsf_canonify(dsf, v1);
366 v2 = dsf_canonify(dsf, v2);
371 unsigned char *marked;
377 static struct todo *todo_new(int maxsize)
379 struct todo *todo = snew(struct todo);
380 todo->marked = snewn(maxsize, unsigned char);
381 memset(todo->marked, 0, maxsize);
382 todo->buflen = maxsize + 1;
383 todo->buffer = snewn(todo->buflen, int);
384 todo->head = todo->tail = 0;
388 static void todo_free(struct todo *todo)
395 static void todo_add(struct todo *todo, int index)
397 if (todo->marked[index])
398 return; /* already on the list */
399 todo->marked[index] = TRUE;
400 todo->buffer[todo->tail++] = index;
401 if (todo->tail == todo->buflen)
405 static int todo_get(struct todo *todo) {
408 if (todo->head == todo->tail)
409 return -1; /* list is empty */
410 ret = todo->buffer[todo->head++];
411 if (todo->head == todo->buflen)
413 todo->marked[ret] = FALSE;
418 static int net_solver(int w, int h, unsigned char *tiles,
419 unsigned char *barriers, int wrapping)
421 unsigned char *tilestate;
422 unsigned char *edgestate;
431 * Set up the solver's data structures.
435 * tilestate stores the possible orientations of each tile.
436 * There are up to four of these, so we'll index the array in
437 * fours. tilestate[(y * w + x) * 4] and its three successive
438 * members give the possible orientations, clearing to 255 from
439 * the end as things are ruled out.
441 * In this loop we also count up the area of the grid (which is
442 * not _necessarily_ equal to w*h, because there might be one
443 * or more blank squares present. This will never happen in a
444 * grid generated _by_ this program, but it's worth keeping the
445 * solver as general as possible.)
447 tilestate = snewn(w * h * 4, unsigned char);
449 for (i = 0; i < w*h; i++) {
450 tilestate[i * 4] = tiles[i] & 0xF;
451 for (j = 1; j < 4; j++) {
452 if (tilestate[i * 4 + j - 1] == 255 ||
453 A(tilestate[i * 4 + j - 1]) == tilestate[i * 4])
454 tilestate[i * 4 + j] = 255;
456 tilestate[i * 4 + j] = A(tilestate[i * 4 + j - 1]);
463 * edgestate stores the known state of each edge. It is 0 for
464 * unknown, 1 for open (connected) and 2 for closed (not
467 * In principle we need only worry about each edge once each,
468 * but in fact it's easier to track each edge twice so that we
469 * can reference it from either side conveniently. Also I'm
470 * going to allocate _five_ bytes per tile, rather than the
471 * obvious four, so that I can index edgestate[(y*w+x) * 5 + d]
472 * where d is 1,2,4,8 and they never overlap.
474 edgestate = snewn((w * h - 1) * 5 + 9, unsigned char);
475 memset(edgestate, 0, (w * h - 1) * 5 + 9);
478 * deadends tracks which edges have dead ends on them. It is
479 * indexed by tile and direction: deadends[(y*w+x) * 5 + d]
480 * tells you whether heading out of tile (x,y) in direction d
481 * can reach a limited amount of the grid. Values are area+1
482 * (no dead end known) or less than that (can reach _at most_
483 * this many other tiles by heading this way out of this tile).
485 deadends = snewn((w * h - 1) * 5 + 9, int);
486 for (i = 0; i < (w * h - 1) * 5 + 9; i++)
487 deadends[i] = area+1;
490 * equivalence tracks which sets of tiles are known to be
491 * connected to one another, so we can avoid creating loops by
492 * linking together tiles which are already linked through
495 * This is a disjoint set forest structure: equivalence[i]
496 * contains the index of another member of the equivalence
497 * class containing i, or contains i itself for precisely one
498 * member in each such class. To find a representative member
499 * of the equivalence class containing i, you keep replacing i
500 * with equivalence[i] until it stops changing; then you go
501 * _back_ along the same path and point everything on it
502 * directly at the representative member so as to speed up
503 * future searches. Then you test equivalence between tiles by
504 * finding the representative of each tile and seeing if
505 * they're the same; and you create new equivalence (merge
506 * classes) by finding the representative of each tile and
507 * setting equivalence[one]=the_other.
509 equivalence = snewn(w * h, int);
510 for (i = 0; i < w*h; i++)
511 equivalence[i] = i; /* initially all distinct */
514 * On a non-wrapping grid, we instantly know that all the edges
515 * round the edge are closed.
518 for (i = 0; i < w; i++) {
519 edgestate[i * 5 + 2] = edgestate[((h-1) * w + i) * 5 + 8] = 2;
521 for (i = 0; i < h; i++) {
522 edgestate[(i * w + w-1) * 5 + 1] = edgestate[(i * w) * 5 + 4] = 2;
527 * If we have barriers available, we can mark those edges as
531 for (y = 0; y < h; y++) for (x = 0; x < w; x++) {
533 for (d = 1; d <= 8; d += d) {
534 if (barriers[y*w+x] & d) {
537 * In principle the barrier list should already
538 * contain each barrier from each side, but
539 * let's not take chances with our internal
542 OFFSETWH(x2, y2, x, y, d, w, h);
543 edgestate[(y*w+x) * 5 + d] = 2;
544 edgestate[(y2*w+x2) * 5 + F(d)] = 2;
551 * Since most deductions made by this solver are local (the
552 * exception is loop avoidance, where joining two tiles
553 * together on one side of the grid can theoretically permit a
554 * fresh deduction on the other), we can address the scaling
555 * problem inherent in iterating repeatedly over the entire
556 * grid by instead working with a to-do list.
558 todo = todo_new(w * h);
561 * Main deductive loop.
563 done_something = TRUE; /* prevent instant termination! */
568 * Take a tile index off the todo list and process it.
570 index = todo_get(todo);
573 * If we have run out of immediate things to do, we
574 * have no choice but to scan the whole grid for
575 * longer-range things we've missed. Hence, I now add
576 * every square on the grid back on to the to-do list.
577 * I also set `done_something' to FALSE at this point;
578 * if we later come back here and find it still FALSE,
579 * we will know we've scanned the entire grid without
580 * finding anything new to do, and we can terminate.
584 for (i = 0; i < w*h; i++)
586 done_something = FALSE;
588 index = todo_get(todo);
594 int d, ourclass = dsf_canonify(equivalence, y*w+x);
597 deadendmax[1] = deadendmax[2] = deadendmax[4] = deadendmax[8] = 0;
599 for (i = j = 0; i < 4 && tilestate[(y*w+x) * 4 + i] != 255; i++) {
601 int nnondeadends, nondeadends[4], deadendtotal;
602 int nequiv, equiv[5];
603 int val = tilestate[(y*w+x) * 4 + i];
606 nnondeadends = deadendtotal = 0;
609 for (d = 1; d <= 8; d += d) {
611 * Immediately rule out this orientation if it
612 * conflicts with any known edge.
614 if ((edgestate[(y*w+x) * 5 + d] == 1 && !(val & d)) ||
615 (edgestate[(y*w+x) * 5 + d] == 2 && (val & d)))
620 * Count up the dead-end statistics.
622 if (deadends[(y*w+x) * 5 + d] <= area) {
623 deadendtotal += deadends[(y*w+x) * 5 + d];
625 nondeadends[nnondeadends++] = d;
629 * Ensure we aren't linking to any tiles,
630 * through edges not already known to be
631 * open, which create a loop.
633 if (edgestate[(y*w+x) * 5 + d] == 0) {
636 OFFSETWH(x2, y2, x, y, d, w, h);
637 c = dsf_canonify(equivalence, y2*w+x2);
638 for (k = 0; k < nequiv; k++)
649 if (nnondeadends == 0) {
651 * If this orientation links together dead-ends
652 * with a total area of less than the entire
653 * grid, it is invalid.
655 * (We add 1 to deadendtotal because of the
656 * tile itself, of course; one tile linking
657 * dead ends of size 2 and 3 forms a subnetwork
658 * with a total area of 6, not 5.)
660 if (deadendtotal > 0 && deadendtotal+1 < area)
662 } else if (nnondeadends == 1) {
664 * If this orientation links together one or
665 * more dead-ends with precisely one
666 * non-dead-end, then we may have to mark that
667 * non-dead-end as a dead end going the other
668 * way. However, it depends on whether all
669 * other orientations share the same property.
672 if (deadendmax[nondeadends[0]] < deadendtotal)
673 deadendmax[nondeadends[0]] = deadendtotal;
676 * If this orientation links together two or
677 * more non-dead-ends, then we can rule out the
678 * possibility of putting in new dead-end
679 * markings in those directions.
682 for (k = 0; k < nnondeadends; k++)
683 deadendmax[nondeadends[k]] = area+1;
687 tilestate[(y*w+x) * 4 + j++] = val;
688 #ifdef SOLVER_DIAGNOSTICS
690 printf("ruling out orientation %x at %d,%d\n", val, x, y);
694 assert(j > 0); /* we can't lose _all_ possibilities! */
697 done_something = TRUE;
700 * We have ruled out at least one tile orientation.
701 * Make sure the rest are blanked.
704 tilestate[(y*w+x) * 4 + j++] = 255;
708 * Now go through the tile orientations again and see
709 * if we've deduced anything new about any edges.
715 for (i = 0; i < 4 && tilestate[(y*w+x) * 4 + i] != 255; i++) {
716 a &= tilestate[(y*w+x) * 4 + i];
717 o |= tilestate[(y*w+x) * 4 + i];
719 for (d = 1; d <= 8; d += d)
720 if (edgestate[(y*w+x) * 5 + d] == 0) {
722 OFFSETWH(x2, y2, x, y, d, w, h);
725 /* This edge is open in all orientations. */
726 #ifdef SOLVER_DIAGNOSTICS
727 printf("marking edge %d,%d:%d open\n", x, y, d);
729 edgestate[(y*w+x) * 5 + d] = 1;
730 edgestate[(y2*w+x2) * 5 + d2] = 1;
731 dsf_merge(equivalence, y*w+x, y2*w+x2);
732 done_something = TRUE;
733 todo_add(todo, y2*w+x2);
734 } else if (!(o & d)) {
735 /* This edge is closed in all orientations. */
736 #ifdef SOLVER_DIAGNOSTICS
737 printf("marking edge %d,%d:%d closed\n", x, y, d);
739 edgestate[(y*w+x) * 5 + d] = 2;
740 edgestate[(y2*w+x2) * 5 + d2] = 2;
741 done_something = TRUE;
742 todo_add(todo, y2*w+x2);
749 * Now check the dead-end markers and see if any of
750 * them has lowered from the real ones.
752 for (d = 1; d <= 8; d += d) {
754 OFFSETWH(x2, y2, x, y, d, w, h);
756 if (deadendmax[d] > 0 &&
757 deadends[(y2*w+x2) * 5 + d2] > deadendmax[d]) {
758 #ifdef SOLVER_DIAGNOSTICS
759 printf("setting dead end value %d,%d:%d to %d\n",
760 x2, y2, d2, deadendmax[d]);
762 deadends[(y2*w+x2) * 5 + d2] = deadendmax[d];
763 done_something = TRUE;
764 todo_add(todo, y2*w+x2);
772 * Mark all completely determined tiles as locked.
775 for (i = 0; i < w*h; i++) {
776 if (tilestate[i * 4 + 1] == 255) {
777 assert(tilestate[i * 4 + 0] != 255);
778 tiles[i] = tilestate[i * 4] | LOCKED;
786 * Free up working space.
797 /* ----------------------------------------------------------------------
798 * Randomly select a new game description.
802 * Function to randomly perturb an ambiguous section in a grid, to
803 * attempt to ensure unique solvability.
805 static void perturb(int w, int h, unsigned char *tiles, int wrapping,
806 random_state *rs, int startx, int starty, int startd)
808 struct xyd *perimeter, *perim2, *loop[2], looppos[2];
809 int nperim, perimsize, nloop[2], loopsize[2];
813 * We know that the tile at (startx,starty) is part of an
814 * ambiguous section, and we also know that its neighbour in
815 * direction startd is fully specified. We begin by tracing all
816 * the way round the ambiguous area.
818 nperim = perimsize = 0;
823 #ifdef PERTURB_DIAGNOSTICS
824 printf("perturb %d,%d:%d\n", x, y, d);
829 if (nperim >= perimsize) {
830 perimsize = perimsize * 3 / 2 + 32;
831 perimeter = sresize(perimeter, perimsize, struct xyd);
833 perimeter[nperim].x = x;
834 perimeter[nperim].y = y;
835 perimeter[nperim].direction = d;
837 #ifdef PERTURB_DIAGNOSTICS
838 printf("perimeter: %d,%d:%d\n", x, y, d);
842 * First, see if we can simply turn left from where we are
843 * and find another locked square.
846 OFFSETWH(x2, y2, x, y, d2, w, h);
847 if ((!wrapping && (abs(x2-x) > 1 || abs(y2-y) > 1)) ||
848 (tiles[y2*w+x2] & LOCKED)) {
852 * Failing that, step left into the new square and look
857 OFFSETWH(x2, y2, x, y, d, w, h);
858 if ((wrapping || (abs(x2-x) <= 1 && abs(y2-y) <= 1)) &&
859 !(tiles[y2*w+x2] & LOCKED)) {
861 * And failing _that_, we're going to have to step
862 * forward into _that_ square and look right at the
863 * same locked square as we started with.
871 } while (x != startx || y != starty || d != startd);
874 * Our technique for perturbing this ambiguous area is to
875 * search round its edge for a join we can make: that is, an
876 * edge on the perimeter which is (a) not currently connected,
877 * and (b) connecting it would not yield a full cross on either
878 * side. Then we make that join, search round the network to
879 * find the loop thus constructed, and sever the loop at a
880 * randomly selected other point.
882 perim2 = snewn(nperim, struct xyd);
883 memcpy(perim2, perimeter, nperim * sizeof(struct xyd));
884 /* Shuffle the perimeter, so as to search it without directional bias. */
885 for (i = nperim; --i ;) {
886 int j = random_upto(rs, i+1);
890 perim2[j] = perim2[i];
893 for (i = 0; i < nperim; i++) {
898 d = perim2[i].direction;
900 OFFSETWH(x2, y2, x, y, d, w, h);
901 if (!wrapping && (abs(x2-x) > 1 || abs(y2-y) > 1))
902 continue; /* can't link across non-wrapping border */
903 if (tiles[y*w+x] & d)
904 continue; /* already linked in this direction! */
905 if (((tiles[y*w+x] | d) & 15) == 15)
906 continue; /* can't turn this tile into a cross */
907 if (((tiles[y2*w+x2] | F(d)) & 15) == 15)
908 continue; /* can't turn other tile into a cross */
911 * We've found the point at which we're going to make a new
914 #ifdef PERTURB_DIAGNOSTICS
915 printf("linking %d,%d:%d\n", x, y, d);
918 tiles[y2*w+x2] |= F(d);
924 return; /* nothing we can do! */
927 * Now we've constructed a new link, we need to find the entire
928 * loop of which it is a part.
930 * In principle, this involves doing a complete search round
931 * the network. However, I anticipate that in the vast majority
932 * of cases the loop will be quite small, so what I'm going to
933 * do is make _two_ searches round the network in parallel, one
934 * keeping its metaphorical hand on the left-hand wall while
935 * the other keeps its hand on the right. As soon as one of
936 * them gets back to its starting point, I abandon the other.
938 for (i = 0; i < 2; i++) {
939 loopsize[i] = nloop[i] = 0;
943 looppos[i].direction = d;
946 for (i = 0; i < 2; i++) {
951 d = looppos[i].direction;
953 OFFSETWH(x2, y2, x, y, d, w, h);
956 * Add this path segment to the loop, unless it exactly
957 * reverses the previous one on the loop in which case
958 * we take it away again.
960 #ifdef PERTURB_DIAGNOSTICS
961 printf("looppos[%d] = %d,%d:%d\n", i, x, y, d);
964 loop[i][nloop[i]-1].x == x2 &&
965 loop[i][nloop[i]-1].y == y2 &&
966 loop[i][nloop[i]-1].direction == F(d)) {
967 #ifdef PERTURB_DIAGNOSTICS
968 printf("removing path segment %d,%d:%d from loop[%d]\n",
973 if (nloop[i] >= loopsize[i]) {
974 loopsize[i] = loopsize[i] * 3 / 2 + 32;
975 loop[i] = sresize(loop[i], loopsize[i], struct xyd);
977 #ifdef PERTURB_DIAGNOSTICS
978 printf("adding path segment %d,%d:%d to loop[%d]\n",
981 loop[i][nloop[i]++] = looppos[i];
984 #ifdef PERTURB_DIAGNOSTICS
985 printf("tile at new location is %x\n", tiles[y2*w+x2] & 0xF);
988 for (j = 0; j < 4; j++) {
993 #ifdef PERTURB_DIAGNOSTICS
994 printf("trying dir %d\n", d);
996 if (tiles[y2*w+x2] & d) {
999 looppos[i].direction = d;
1005 assert(nloop[i] > 0);
1007 if (looppos[i].x == loop[i][0].x &&
1008 looppos[i].y == loop[i][0].y &&
1009 looppos[i].direction == loop[i][0].direction) {
1010 #ifdef PERTURB_DIAGNOSTICS
1011 printf("loop %d finished tracking\n", i);
1015 * Having found our loop, we now sever it at a
1016 * randomly chosen point - absolutely any will do -
1017 * which is not the one we joined it at to begin
1018 * with. Conveniently, the one we joined it at is
1019 * loop[i][0], so we just avoid that one.
1021 j = random_upto(rs, nloop[i]-1) + 1;
1024 d = loop[i][j].direction;
1025 OFFSETWH(x2, y2, x, y, d, w, h);
1027 tiles[y2*w+x2] &= ~F(d);
1039 * Finally, we must mark the entire disputed section as locked,
1040 * to prevent the perturb function being called on it multiple
1043 * To do this, we _sort_ the perimeter of the area. The
1044 * existing xyd_cmp function will arrange things into columns
1045 * for us, in such a way that each column has the edges in
1046 * vertical order. Then we can work down each column and fill
1047 * in all the squares between an up edge and a down edge.
1049 qsort(perimeter, nperim, sizeof(struct xyd), xyd_cmp);
1051 for (i = 0; i <= nperim; i++) {
1052 if (i == nperim || perimeter[i].x > x) {
1054 * Fill in everything from the last Up edge to the
1055 * bottom of the grid, if necessary.
1059 #ifdef PERTURB_DIAGNOSTICS
1060 printf("resolved: locking tile %d,%d\n", x, y);
1062 tiles[y * w + x] |= LOCKED;
1075 if (perimeter[i].direction == U) {
1078 } else if (perimeter[i].direction == D) {
1080 * Fill in everything from the last Up edge to here.
1082 assert(x == perimeter[i].x && y <= perimeter[i].y);
1083 while (y <= perimeter[i].y) {
1084 #ifdef PERTURB_DIAGNOSTICS
1085 printf("resolved: locking tile %d,%d\n", x, y);
1087 tiles[y * w + x] |= LOCKED;
1097 static char *new_game_desc(game_params *params, random_state *rs,
1098 game_aux_info **aux)
1100 tree234 *possibilities, *barriertree;
1101 int w, h, x, y, cx, cy, nbarriers;
1102 unsigned char *tiles, *barriers;
1111 tiles = snewn(w * h, unsigned char);
1112 barriers = snewn(w * h, unsigned char);
1116 memset(tiles, 0, w * h);
1117 memset(barriers, 0, w * h);
1120 * Construct the unshuffled grid.
1122 * To do this, we simply start at the centre point, repeatedly
1123 * choose a random possibility out of the available ways to
1124 * extend a used square into an unused one, and do it. After
1125 * extending the third line out of a square, we remove the
1126 * fourth from the possibilities list to avoid any full-cross
1127 * squares (which would make the game too easy because they
1128 * only have one orientation).
1130 * The slightly worrying thing is the avoidance of full-cross
1131 * squares. Can this cause our unsophisticated construction
1132 * algorithm to paint itself into a corner, by getting into a
1133 * situation where there are some unreached squares and the
1134 * only way to reach any of them is to extend a T-piece into a
1137 * Answer: no it can't, and here's a proof.
1139 * Any contiguous group of such unreachable squares must be
1140 * surrounded on _all_ sides by T-pieces pointing away from the
1141 * group. (If not, then there is a square which can be extended
1142 * into one of the `unreachable' ones, and so it wasn't
1143 * unreachable after all.) In particular, this implies that
1144 * each contiguous group of unreachable squares must be
1145 * rectangular in shape (any deviation from that yields a
1146 * non-T-piece next to an `unreachable' square).
1148 * So we have a rectangle of unreachable squares, with T-pieces
1149 * forming a solid border around the rectangle. The corners of
1150 * that border must be connected (since every tile connects all
1151 * the lines arriving in it), and therefore the border must
1152 * form a closed loop around the rectangle.
1154 * But this can't have happened in the first place, since we
1155 * _know_ we've avoided creating closed loops! Hence, no such
1156 * situation can ever arise, and the naive grid construction
1157 * algorithm will guaranteeably result in a complete grid
1158 * containing no unreached squares, no full crosses _and_ no
1161 possibilities = newtree234(xyd_cmp_nc);
1164 add234(possibilities, new_xyd(cx, cy, R));
1166 add234(possibilities, new_xyd(cx, cy, U));
1168 add234(possibilities, new_xyd(cx, cy, L));
1170 add234(possibilities, new_xyd(cx, cy, D));
1172 while (count234(possibilities) > 0) {
1175 int x1, y1, d1, x2, y2, d2, d;
1178 * Extract a randomly chosen possibility from the list.
1180 i = random_upto(rs, count234(possibilities));
1181 xyd = delpos234(possibilities, i);
1184 d1 = xyd->direction;
1187 OFFSET(x2, y2, x1, y1, d1, params);
1190 printf("picked (%d,%d,%c) <-> (%d,%d,%c)\n",
1191 x1, y1, "0RU3L567D9abcdef"[d1], x2, y2, "0RU3L567D9abcdef"[d2]);
1195 * Make the connection. (We should be moving to an as yet
1198 index(params, tiles, x1, y1) |= d1;
1199 assert(index(params, tiles, x2, y2) == 0);
1200 index(params, tiles, x2, y2) |= d2;
1203 * If we have created a T-piece, remove its last
1206 if (COUNT(index(params, tiles, x1, y1)) == 3) {
1207 struct xyd xyd1, *xydp;
1211 xyd1.direction = 0x0F ^ index(params, tiles, x1, y1);
1213 xydp = find234(possibilities, &xyd1, NULL);
1217 printf("T-piece; removing (%d,%d,%c)\n",
1218 xydp->x, xydp->y, "0RU3L567D9abcdef"[xydp->direction]);
1220 del234(possibilities, xydp);
1226 * Remove all other possibilities that were pointing at the
1227 * tile we've just moved into.
1229 for (d = 1; d < 0x10; d <<= 1) {
1231 struct xyd xyd1, *xydp;
1233 OFFSET(x3, y3, x2, y2, d, params);
1238 xyd1.direction = d3;
1240 xydp = find234(possibilities, &xyd1, NULL);
1244 printf("Loop avoidance; removing (%d,%d,%c)\n",
1245 xydp->x, xydp->y, "0RU3L567D9abcdef"[xydp->direction]);
1247 del234(possibilities, xydp);
1253 * Add new possibilities to the list for moving _out_ of
1254 * the tile we have just moved into.
1256 for (d = 1; d < 0x10; d <<= 1) {
1260 continue; /* we've got this one already */
1262 if (!params->wrapping) {
1263 if (d == U && y2 == 0)
1265 if (d == D && y2 == h-1)
1267 if (d == L && x2 == 0)
1269 if (d == R && x2 == w-1)
1273 OFFSET(x3, y3, x2, y2, d, params);
1275 if (index(params, tiles, x3, y3))
1276 continue; /* this would create a loop */
1279 printf("New frontier; adding (%d,%d,%c)\n",
1280 x2, y2, "0RU3L567D9abcdef"[d]);
1282 add234(possibilities, new_xyd(x2, y2, d));
1285 /* Having done that, we should have no possibilities remaining. */
1286 assert(count234(possibilities) == 0);
1287 freetree234(possibilities);
1289 if (params->unique) {
1293 * Run the solver to check unique solubility.
1295 while (!net_solver(w, h, tiles, NULL, params->wrapping)) {
1299 * We expect (in most cases) that most of the grid will
1300 * be uniquely specified already, and the remaining
1301 * ambiguous sections will be small and separate. So
1302 * our strategy is to find each individual such
1303 * section, and perform a perturbation on the network
1306 for (y = 0; y < h; y++) for (x = 0; x < w; x++) {
1307 if (x+1 < w && ((tiles[y*w+x] ^ tiles[y*w+x+1]) & LOCKED)) {
1309 if (tiles[y*w+x] & LOCKED)
1310 perturb(w, h, tiles, params->wrapping, rs, x+1, y, L);
1312 perturb(w, h, tiles, params->wrapping, rs, x, y, R);
1314 if (y+1 < h && ((tiles[y*w+x] ^ tiles[(y+1)*w+x]) & LOCKED)) {
1316 if (tiles[y*w+x] & LOCKED)
1317 perturb(w, h, tiles, params->wrapping, rs, x, y+1, U);
1319 perturb(w, h, tiles, params->wrapping, rs, x, y, D);
1324 * Now n counts the number of ambiguous sections we
1325 * have fiddled with. If we haven't managed to decrease
1326 * it from the last time we ran the solver, give up and
1327 * regenerate the entire grid.
1329 if (prevn != -1 && prevn <= n)
1330 goto begin_generation; /* (sorry) */
1336 * The solver will have left a lot of LOCKED bits lying
1337 * around in the tiles array. Remove them.
1339 for (x = 0; x < w*h; x++)
1340 tiles[x] &= ~LOCKED;
1344 * Now compute a list of the possible barrier locations.
1346 barriertree = newtree234(xyd_cmp_nc);
1347 for (y = 0; y < h; y++) {
1348 for (x = 0; x < w; x++) {
1350 if (!(index(params, tiles, x, y) & R) &&
1351 (params->wrapping || x < w-1))
1352 add234(barriertree, new_xyd(x, y, R));
1353 if (!(index(params, tiles, x, y) & D) &&
1354 (params->wrapping || y < h-1))
1355 add234(barriertree, new_xyd(x, y, D));
1360 * Save the unshuffled grid in an aux_info.
1363 game_aux_info *solution;
1365 solution = snew(game_aux_info);
1366 solution->width = w;
1367 solution->height = h;
1368 solution->tiles = snewn(w * h, unsigned char);
1369 memcpy(solution->tiles, tiles, w * h);
1375 * Now shuffle the grid.
1377 for (y = 0; y < h; y++) {
1378 for (x = 0; x < w; x++) {
1379 int orig = index(params, tiles, x, y);
1380 int rot = random_upto(rs, 4);
1381 index(params, tiles, x, y) = ROT(orig, rot);
1386 * And now choose barrier locations. (We carefully do this
1387 * _after_ shuffling, so that changing the barrier rate in the
1388 * params while keeping the random seed the same will give the
1389 * same shuffled grid and _only_ change the barrier locations.
1390 * Also the way we choose barrier locations, by repeatedly
1391 * choosing one possibility from the list until we have enough,
1392 * is designed to ensure that raising the barrier rate while
1393 * keeping the seed the same will provide a superset of the
1394 * previous barrier set - i.e. if you ask for 10 barriers, and
1395 * then decide that's still too hard and ask for 20, you'll get
1396 * the original 10 plus 10 more, rather than getting 20 new
1397 * ones and the chance of remembering your first 10.)
1399 nbarriers = (int)(params->barrier_probability * count234(barriertree));
1400 assert(nbarriers >= 0 && nbarriers <= count234(barriertree));
1402 while (nbarriers > 0) {
1405 int x1, y1, d1, x2, y2, d2;
1408 * Extract a randomly chosen barrier from the list.
1410 i = random_upto(rs, count234(barriertree));
1411 xyd = delpos234(barriertree, i);
1413 assert(xyd != NULL);
1417 d1 = xyd->direction;
1420 OFFSET(x2, y2, x1, y1, d1, params);
1423 index(params, barriers, x1, y1) |= d1;
1424 index(params, barriers, x2, y2) |= d2;
1430 * Clean up the rest of the barrier list.
1435 while ( (xyd = delpos234(barriertree, 0)) != NULL)
1438 freetree234(barriertree);
1442 * Finally, encode the grid into a string game description.
1444 * My syntax is extremely simple: each square is encoded as a
1445 * hex digit in which bit 0 means a connection on the right,
1446 * bit 1 means up, bit 2 left and bit 3 down. (i.e. the same
1447 * encoding as used internally). Each digit is followed by
1448 * optional barrier indicators: `v' means a vertical barrier to
1449 * the right of it, and `h' means a horizontal barrier below
1452 desc = snewn(w * h * 3 + 1, char);
1454 for (y = 0; y < h; y++) {
1455 for (x = 0; x < w; x++) {
1456 *p++ = "0123456789abcdef"[index(params, tiles, x, y)];
1457 if ((params->wrapping || x < w-1) &&
1458 (index(params, barriers, x, y) & R))
1460 if ((params->wrapping || y < h-1) &&
1461 (index(params, barriers, x, y) & D))
1465 assert(p - desc <= w*h*3);
1474 static void game_free_aux_info(game_aux_info *aux)
1480 static char *validate_desc(game_params *params, char *desc)
1482 int w = params->width, h = params->height;
1485 for (i = 0; i < w*h; i++) {
1486 if (*desc >= '0' && *desc <= '9')
1488 else if (*desc >= 'a' && *desc <= 'f')
1490 else if (*desc >= 'A' && *desc <= 'F')
1493 return "Game description shorter than expected";
1495 return "Game description contained unexpected character";
1497 while (*desc == 'h' || *desc == 'v')
1501 return "Game description longer than expected";
1506 /* ----------------------------------------------------------------------
1507 * Construct an initial game state, given a description and parameters.
1510 static game_state *new_game(game_params *params, char *desc)
1515 assert(params->width > 0 && params->height > 0);
1516 assert(params->width > 1 || params->height > 1);
1519 * Create a blank game state.
1521 state = snew(game_state);
1522 w = state->width = params->width;
1523 h = state->height = params->height;
1524 state->cx = state->width / 2;
1525 state->cy = state->height / 2;
1526 state->wrapping = params->wrapping;
1527 state->last_rotate_dir = state->last_rotate_x = state->last_rotate_y = 0;
1528 state->completed = state->used_solve = state->just_used_solve = FALSE;
1529 state->tiles = snewn(state->width * state->height, unsigned char);
1530 memset(state->tiles, 0, state->width * state->height);
1531 state->barriers = snewn(state->width * state->height, unsigned char);
1532 memset(state->barriers, 0, state->width * state->height);
1535 * Parse the game description into the grid.
1537 for (y = 0; y < h; y++) {
1538 for (x = 0; x < w; x++) {
1539 if (*desc >= '0' && *desc <= '9')
1540 tile(state, x, y) = *desc - '0';
1541 else if (*desc >= 'a' && *desc <= 'f')
1542 tile(state, x, y) = *desc - 'a' + 10;
1543 else if (*desc >= 'A' && *desc <= 'F')
1544 tile(state, x, y) = *desc - 'A' + 10;
1547 while (*desc == 'h' || *desc == 'v') {
1554 OFFSET(x2, y2, x, y, d1, state);
1557 barrier(state, x, y) |= d1;
1558 barrier(state, x2, y2) |= d2;
1566 * Set up border barriers if this is a non-wrapping game.
1568 if (!state->wrapping) {
1569 for (x = 0; x < state->width; x++) {
1570 barrier(state, x, 0) |= U;
1571 barrier(state, x, state->height-1) |= D;
1573 for (y = 0; y < state->height; y++) {
1574 barrier(state, 0, y) |= L;
1575 barrier(state, state->width-1, y) |= R;
1580 * Set up the barrier corner flags, for drawing barriers
1581 * prettily when they meet.
1583 for (y = 0; y < state->height; y++) {
1584 for (x = 0; x < state->width; x++) {
1587 for (dir = 1; dir < 0x10; dir <<= 1) {
1589 int x1, y1, x2, y2, x3, y3;
1592 if (!(barrier(state, x, y) & dir))
1595 if (barrier(state, x, y) & dir2)
1598 x1 = x + X(dir), y1 = y + Y(dir);
1599 if (x1 >= 0 && x1 < state->width &&
1600 y1 >= 0 && y1 < state->height &&
1601 (barrier(state, x1, y1) & dir2))
1604 x2 = x + X(dir2), y2 = y + Y(dir2);
1605 if (x2 >= 0 && x2 < state->width &&
1606 y2 >= 0 && y2 < state->height &&
1607 (barrier(state, x2, y2) & dir))
1611 barrier(state, x, y) |= (dir << 4);
1612 if (x1 >= 0 && x1 < state->width &&
1613 y1 >= 0 && y1 < state->height)
1614 barrier(state, x1, y1) |= (A(dir) << 4);
1615 if (x2 >= 0 && x2 < state->width &&
1616 y2 >= 0 && y2 < state->height)
1617 barrier(state, x2, y2) |= (C(dir) << 4);
1618 x3 = x + X(dir) + X(dir2), y3 = y + Y(dir) + Y(dir2);
1619 if (x3 >= 0 && x3 < state->width &&
1620 y3 >= 0 && y3 < state->height)
1621 barrier(state, x3, y3) |= (F(dir) << 4);
1630 static game_state *dup_game(game_state *state)
1634 ret = snew(game_state);
1635 ret->width = state->width;
1636 ret->height = state->height;
1637 ret->cx = state->cx;
1638 ret->cy = state->cy;
1639 ret->wrapping = state->wrapping;
1640 ret->completed = state->completed;
1641 ret->used_solve = state->used_solve;
1642 ret->just_used_solve = state->just_used_solve;
1643 ret->last_rotate_dir = state->last_rotate_dir;
1644 ret->last_rotate_x = state->last_rotate_x;
1645 ret->last_rotate_y = state->last_rotate_y;
1646 ret->tiles = snewn(state->width * state->height, unsigned char);
1647 memcpy(ret->tiles, state->tiles, state->width * state->height);
1648 ret->barriers = snewn(state->width * state->height, unsigned char);
1649 memcpy(ret->barriers, state->barriers, state->width * state->height);
1654 static void free_game(game_state *state)
1656 sfree(state->tiles);
1657 sfree(state->barriers);
1661 static game_state *solve_game(game_state *state, game_aux_info *aux,
1668 * Run the internal solver on the provided grid. This might
1669 * not yield a complete solution.
1671 ret = dup_game(state);
1672 net_solver(ret->width, ret->height, ret->tiles,
1673 ret->barriers, ret->wrapping);
1675 assert(aux->width == state->width);
1676 assert(aux->height == state->height);
1677 ret = dup_game(state);
1678 memcpy(ret->tiles, aux->tiles, ret->width * ret->height);
1679 ret->used_solve = ret->just_used_solve = TRUE;
1680 ret->completed = TRUE;
1686 static char *game_text_format(game_state *state)
1691 /* ----------------------------------------------------------------------
1696 * Compute which squares are reachable from the centre square, as a
1697 * quick visual aid to determining how close the game is to
1698 * completion. This is also a simple way to tell if the game _is_
1699 * completed - just call this function and see whether every square
1702 static unsigned char *compute_active(game_state *state)
1704 unsigned char *active;
1708 active = snewn(state->width * state->height, unsigned char);
1709 memset(active, 0, state->width * state->height);
1712 * We only store (x,y) pairs in todo, but it's easier to reuse
1713 * xyd_cmp and just store direction 0 every time.
1715 todo = newtree234(xyd_cmp_nc);
1716 index(state, active, state->cx, state->cy) = ACTIVE;
1717 add234(todo, new_xyd(state->cx, state->cy, 0));
1719 while ( (xyd = delpos234(todo, 0)) != NULL) {
1720 int x1, y1, d1, x2, y2, d2;
1726 for (d1 = 1; d1 < 0x10; d1 <<= 1) {
1727 OFFSET(x2, y2, x1, y1, d1, state);
1731 * If the next tile in this direction is connected to
1732 * us, and there isn't a barrier in the way, and it
1733 * isn't already marked active, then mark it active and
1734 * add it to the to-examine list.
1736 if ((tile(state, x1, y1) & d1) &&
1737 (tile(state, x2, y2) & d2) &&
1738 !(barrier(state, x1, y1) & d1) &&
1739 !index(state, active, x2, y2)) {
1740 index(state, active, x2, y2) = ACTIVE;
1741 add234(todo, new_xyd(x2, y2, 0));
1745 /* Now we expect the todo list to have shrunk to zero size. */
1746 assert(count234(todo) == 0);
1755 random_state *rs; /* used for jumbling */
1758 static game_ui *new_ui(game_state *state)
1762 game_ui *ui = snew(game_ui);
1763 ui->cur_x = state->width / 2;
1764 ui->cur_y = state->height / 2;
1765 ui->cur_visible = FALSE;
1766 get_random_seed(&seed, &seedsize);
1767 ui->rs = random_init(seed, seedsize);
1773 static void free_ui(game_ui *ui)
1775 random_free(ui->rs);
1779 /* ----------------------------------------------------------------------
1782 static game_state *make_move(game_state *state, game_ui *ui,
1783 int x, int y, int button)
1785 game_state *ret, *nullret;
1790 if (button == LEFT_BUTTON ||
1791 button == MIDDLE_BUTTON ||
1792 button == RIGHT_BUTTON) {
1794 if (ui->cur_visible) {
1795 ui->cur_visible = FALSE;
1800 * The button must have been clicked on a valid tile.
1802 x -= WINDOW_OFFSET + TILE_BORDER;
1803 y -= WINDOW_OFFSET + TILE_BORDER;
1808 if (tx >= state->width || ty >= state->height)
1810 if (x % TILE_SIZE >= TILE_SIZE - TILE_BORDER ||
1811 y % TILE_SIZE >= TILE_SIZE - TILE_BORDER)
1813 } else if (button == CURSOR_UP || button == CURSOR_DOWN ||
1814 button == CURSOR_RIGHT || button == CURSOR_LEFT) {
1815 if (button == CURSOR_UP && ui->cur_y > 0)
1817 else if (button == CURSOR_DOWN && ui->cur_y < state->height-1)
1819 else if (button == CURSOR_LEFT && ui->cur_x > 0)
1821 else if (button == CURSOR_RIGHT && ui->cur_x < state->width-1)
1824 return nullret; /* no cursor movement */
1825 ui->cur_visible = TRUE;
1826 return state; /* UI activity has occurred */
1827 } else if (button == 'a' || button == 's' || button == 'd' ||
1828 button == 'A' || button == 'S' || button == 'D') {
1831 if (button == 'a' || button == 'A')
1832 button = LEFT_BUTTON;
1833 else if (button == 's' || button == 'S')
1834 button = MIDDLE_BUTTON;
1835 else if (button == 'd' || button == 'D')
1836 button = RIGHT_BUTTON;
1837 ui->cur_visible = TRUE;
1838 } else if (button == 'j' || button == 'J') {
1839 /* XXX should we have some mouse control for this? */
1840 button = 'J'; /* canonify */
1841 tx = ty = -1; /* shut gcc up :( */
1846 * The middle button locks or unlocks a tile. (A locked tile
1847 * cannot be turned, and is visually marked as being locked.
1848 * This is a convenience for the player, so that once they are
1849 * sure which way round a tile goes, they can lock it and thus
1850 * avoid forgetting later on that they'd already done that one;
1851 * and the locking also prevents them turning the tile by
1852 * accident. If they change their mind, another middle click
1855 if (button == MIDDLE_BUTTON) {
1857 ret = dup_game(state);
1858 ret->just_used_solve = FALSE;
1859 tile(ret, tx, ty) ^= LOCKED;
1860 ret->last_rotate_dir = ret->last_rotate_x = ret->last_rotate_y = 0;
1863 } else if (button == LEFT_BUTTON || button == RIGHT_BUTTON) {
1866 * The left and right buttons have no effect if clicked on a
1869 if (tile(state, tx, ty) & LOCKED)
1873 * Otherwise, turn the tile one way or the other. Left button
1874 * turns anticlockwise; right button turns clockwise.
1876 ret = dup_game(state);
1877 ret->just_used_solve = FALSE;
1878 orig = tile(ret, tx, ty);
1879 if (button == LEFT_BUTTON) {
1880 tile(ret, tx, ty) = A(orig);
1881 ret->last_rotate_dir = +1;
1883 tile(ret, tx, ty) = C(orig);
1884 ret->last_rotate_dir = -1;
1886 ret->last_rotate_x = tx;
1887 ret->last_rotate_y = ty;
1889 } else if (button == 'J') {
1892 * Jumble all unlocked tiles to random orientations.
1895 ret = dup_game(state);
1896 ret->just_used_solve = FALSE;
1897 for (jy = 0; jy < ret->height; jy++) {
1898 for (jx = 0; jx < ret->width; jx++) {
1899 if (!(tile(ret, jx, jy) & LOCKED)) {
1900 int rot = random_upto(ui->rs, 4);
1901 orig = tile(ret, jx, jy);
1902 tile(ret, jx, jy) = ROT(orig, rot);
1906 ret->last_rotate_dir = 0; /* suppress animation */
1907 ret->last_rotate_x = ret->last_rotate_y = 0;
1912 * Check whether the game has been completed.
1915 unsigned char *active = compute_active(ret);
1917 int complete = TRUE;
1919 for (x1 = 0; x1 < ret->width; x1++)
1920 for (y1 = 0; y1 < ret->height; y1++)
1921 if ((tile(ret, x1, y1) & 0xF) && !index(ret, active, x1, y1)) {
1923 goto break_label; /* break out of two loops at once */
1930 ret->completed = TRUE;
1936 /* ----------------------------------------------------------------------
1937 * Routines for drawing the game position on the screen.
1940 struct game_drawstate {
1943 unsigned char *visible;
1946 static game_drawstate *game_new_drawstate(game_state *state)
1948 game_drawstate *ds = snew(game_drawstate);
1950 ds->started = FALSE;
1951 ds->width = state->width;
1952 ds->height = state->height;
1953 ds->visible = snewn(state->width * state->height, unsigned char);
1954 memset(ds->visible, 0xFF, state->width * state->height);
1959 static void game_free_drawstate(game_drawstate *ds)
1965 static void game_size(game_params *params, int *x, int *y)
1967 *x = WINDOW_OFFSET * 2 + TILE_SIZE * params->width + TILE_BORDER;
1968 *y = WINDOW_OFFSET * 2 + TILE_SIZE * params->height + TILE_BORDER;
1971 static float *game_colours(frontend *fe, game_state *state, int *ncolours)
1975 ret = snewn(NCOLOURS * 3, float);
1976 *ncolours = NCOLOURS;
1979 * Basic background colour is whatever the front end thinks is
1980 * a sensible default.
1982 frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
1987 ret[COL_WIRE * 3 + 0] = 0.0F;
1988 ret[COL_WIRE * 3 + 1] = 0.0F;
1989 ret[COL_WIRE * 3 + 2] = 0.0F;
1992 * Powered wires and powered endpoints are cyan.
1994 ret[COL_POWERED * 3 + 0] = 0.0F;
1995 ret[COL_POWERED * 3 + 1] = 1.0F;
1996 ret[COL_POWERED * 3 + 2] = 1.0F;
2001 ret[COL_BARRIER * 3 + 0] = 1.0F;
2002 ret[COL_BARRIER * 3 + 1] = 0.0F;
2003 ret[COL_BARRIER * 3 + 2] = 0.0F;
2006 * Unpowered endpoints are blue.
2008 ret[COL_ENDPOINT * 3 + 0] = 0.0F;
2009 ret[COL_ENDPOINT * 3 + 1] = 0.0F;
2010 ret[COL_ENDPOINT * 3 + 2] = 1.0F;
2013 * Tile borders are a darker grey than the background.
2015 ret[COL_BORDER * 3 + 0] = 0.5F * ret[COL_BACKGROUND * 3 + 0];
2016 ret[COL_BORDER * 3 + 1] = 0.5F * ret[COL_BACKGROUND * 3 + 1];
2017 ret[COL_BORDER * 3 + 2] = 0.5F * ret[COL_BACKGROUND * 3 + 2];
2020 * Locked tiles are a grey in between those two.
2022 ret[COL_LOCKED * 3 + 0] = 0.75F * ret[COL_BACKGROUND * 3 + 0];
2023 ret[COL_LOCKED * 3 + 1] = 0.75F * ret[COL_BACKGROUND * 3 + 1];
2024 ret[COL_LOCKED * 3 + 2] = 0.75F * ret[COL_BACKGROUND * 3 + 2];
2029 static void draw_thick_line(frontend *fe, int x1, int y1, int x2, int y2,
2032 draw_line(fe, x1-1, y1, x2-1, y2, COL_WIRE);
2033 draw_line(fe, x1+1, y1, x2+1, y2, COL_WIRE);
2034 draw_line(fe, x1, y1-1, x2, y2-1, COL_WIRE);
2035 draw_line(fe, x1, y1+1, x2, y2+1, COL_WIRE);
2036 draw_line(fe, x1, y1, x2, y2, colour);
2039 static void draw_rect_coords(frontend *fe, int x1, int y1, int x2, int y2,
2042 int mx = (x1 < x2 ? x1 : x2);
2043 int my = (y1 < y2 ? y1 : y2);
2044 int dx = (x2 + x1 - 2*mx + 1);
2045 int dy = (y2 + y1 - 2*my + 1);
2047 draw_rect(fe, mx, my, dx, dy, colour);
2050 static void draw_barrier_corner(frontend *fe, int x, int y, int dir, int phase)
2052 int bx = WINDOW_OFFSET + TILE_SIZE * x;
2053 int by = WINDOW_OFFSET + TILE_SIZE * y;
2054 int x1, y1, dx, dy, dir2;
2059 dx = X(dir) + X(dir2);
2060 dy = Y(dir) + Y(dir2);
2061 x1 = (dx > 0 ? TILE_SIZE+TILE_BORDER-1 : 0);
2062 y1 = (dy > 0 ? TILE_SIZE+TILE_BORDER-1 : 0);
2065 draw_rect_coords(fe, bx+x1, by+y1,
2066 bx+x1-TILE_BORDER*dx, by+y1-(TILE_BORDER-1)*dy,
2068 draw_rect_coords(fe, bx+x1, by+y1,
2069 bx+x1-(TILE_BORDER-1)*dx, by+y1-TILE_BORDER*dy,
2072 draw_rect_coords(fe, bx+x1, by+y1,
2073 bx+x1-(TILE_BORDER-1)*dx, by+y1-(TILE_BORDER-1)*dy,
2078 static void draw_barrier(frontend *fe, int x, int y, int dir, int phase)
2080 int bx = WINDOW_OFFSET + TILE_SIZE * x;
2081 int by = WINDOW_OFFSET + TILE_SIZE * y;
2084 x1 = (X(dir) > 0 ? TILE_SIZE : X(dir) == 0 ? TILE_BORDER : 0);
2085 y1 = (Y(dir) > 0 ? TILE_SIZE : Y(dir) == 0 ? TILE_BORDER : 0);
2086 w = (X(dir) ? TILE_BORDER : TILE_SIZE - TILE_BORDER);
2087 h = (Y(dir) ? TILE_BORDER : TILE_SIZE - TILE_BORDER);
2090 draw_rect(fe, bx+x1-X(dir), by+y1-Y(dir), w, h, COL_WIRE);
2092 draw_rect(fe, bx+x1, by+y1, w, h, COL_BARRIER);
2096 static void draw_tile(frontend *fe, game_state *state, int x, int y, int tile,
2097 float angle, int cursor)
2099 int bx = WINDOW_OFFSET + TILE_SIZE * x;
2100 int by = WINDOW_OFFSET + TILE_SIZE * y;
2102 float cx, cy, ex, ey, tx, ty;
2103 int dir, col, phase;
2106 * When we draw a single tile, we must draw everything up to
2107 * and including the borders around the tile. This means that
2108 * if the neighbouring tiles have connections to those borders,
2109 * we must draw those connections on the borders themselves.
2111 * This would be terribly fiddly if we ever had to draw a tile
2112 * while its neighbour was in mid-rotate, because we'd have to
2113 * arrange to _know_ that the neighbour was being rotated and
2114 * hence had an anomalous effect on the redraw of this tile.
2115 * Fortunately, the drawing algorithm avoids ever calling us in
2116 * this circumstance: we're either drawing lots of straight
2117 * tiles at game start or after a move is complete, or we're
2118 * repeatedly drawing only the rotating tile. So no problem.
2122 * So. First blank the tile out completely: draw a big
2123 * rectangle in border colour, and a smaller rectangle in
2124 * background colour to fill it in.
2126 draw_rect(fe, bx, by, TILE_SIZE+TILE_BORDER, TILE_SIZE+TILE_BORDER,
2128 draw_rect(fe, bx+TILE_BORDER, by+TILE_BORDER,
2129 TILE_SIZE-TILE_BORDER, TILE_SIZE-TILE_BORDER,
2130 tile & LOCKED ? COL_LOCKED : COL_BACKGROUND);
2133 * Draw an inset outline rectangle as a cursor, in whichever of
2134 * COL_LOCKED and COL_BACKGROUND we aren't currently drawing
2138 draw_line(fe, bx+TILE_SIZE/8, by+TILE_SIZE/8,
2139 bx+TILE_SIZE/8, by+TILE_SIZE-TILE_SIZE/8,
2140 tile & LOCKED ? COL_BACKGROUND : COL_LOCKED);
2141 draw_line(fe, bx+TILE_SIZE/8, by+TILE_SIZE/8,
2142 bx+TILE_SIZE-TILE_SIZE/8, by+TILE_SIZE/8,
2143 tile & LOCKED ? COL_BACKGROUND : COL_LOCKED);
2144 draw_line(fe, bx+TILE_SIZE-TILE_SIZE/8, by+TILE_SIZE/8,
2145 bx+TILE_SIZE-TILE_SIZE/8, by+TILE_SIZE-TILE_SIZE/8,
2146 tile & LOCKED ? COL_BACKGROUND : COL_LOCKED);
2147 draw_line(fe, bx+TILE_SIZE/8, by+TILE_SIZE-TILE_SIZE/8,
2148 bx+TILE_SIZE-TILE_SIZE/8, by+TILE_SIZE-TILE_SIZE/8,
2149 tile & LOCKED ? COL_BACKGROUND : COL_LOCKED);
2153 * Set up the rotation matrix.
2155 matrix[0] = (float)cos(angle * PI / 180.0);
2156 matrix[1] = (float)-sin(angle * PI / 180.0);
2157 matrix[2] = (float)sin(angle * PI / 180.0);
2158 matrix[3] = (float)cos(angle * PI / 180.0);
2163 cx = cy = TILE_BORDER + (TILE_SIZE-TILE_BORDER) / 2.0F - 0.5F;
2164 col = (tile & ACTIVE ? COL_POWERED : COL_WIRE);
2165 for (dir = 1; dir < 0x10; dir <<= 1) {
2167 ex = (TILE_SIZE - TILE_BORDER - 1.0F) / 2.0F * X(dir);
2168 ey = (TILE_SIZE - TILE_BORDER - 1.0F) / 2.0F * Y(dir);
2169 MATMUL(tx, ty, matrix, ex, ey);
2170 draw_thick_line(fe, bx+(int)cx, by+(int)cy,
2171 bx+(int)(cx+tx), by+(int)(cy+ty),
2175 for (dir = 1; dir < 0x10; dir <<= 1) {
2177 ex = (TILE_SIZE - TILE_BORDER - 1.0F) / 2.0F * X(dir);
2178 ey = (TILE_SIZE - TILE_BORDER - 1.0F) / 2.0F * Y(dir);
2179 MATMUL(tx, ty, matrix, ex, ey);
2180 draw_line(fe, bx+(int)cx, by+(int)cy,
2181 bx+(int)(cx+tx), by+(int)(cy+ty), col);
2186 * Draw the box in the middle. We do this in blue if the tile
2187 * is an unpowered endpoint, in cyan if the tile is a powered
2188 * endpoint, in black if the tile is the centrepiece, and
2189 * otherwise not at all.
2192 if (x == state->cx && y == state->cy)
2194 else if (COUNT(tile) == 1) {
2195 col = (tile & ACTIVE ? COL_POWERED : COL_ENDPOINT);
2200 points[0] = +1; points[1] = +1;
2201 points[2] = +1; points[3] = -1;
2202 points[4] = -1; points[5] = -1;
2203 points[6] = -1; points[7] = +1;
2205 for (i = 0; i < 8; i += 2) {
2206 ex = (TILE_SIZE * 0.24F) * points[i];
2207 ey = (TILE_SIZE * 0.24F) * points[i+1];
2208 MATMUL(tx, ty, matrix, ex, ey);
2209 points[i] = bx+(int)(cx+tx);
2210 points[i+1] = by+(int)(cy+ty);
2213 draw_polygon(fe, points, 4, TRUE, col);
2214 draw_polygon(fe, points, 4, FALSE, COL_WIRE);
2218 * Draw the points on the border if other tiles are connected
2221 for (dir = 1; dir < 0x10; dir <<= 1) {
2222 int dx, dy, px, py, lx, ly, vx, vy, ox, oy;
2230 if (ox < 0 || ox >= state->width || oy < 0 || oy >= state->height)
2233 if (!(tile(state, ox, oy) & F(dir)))
2236 px = bx + (int)(dx>0 ? TILE_SIZE + TILE_BORDER - 1 : dx<0 ? 0 : cx);
2237 py = by + (int)(dy>0 ? TILE_SIZE + TILE_BORDER - 1 : dy<0 ? 0 : cy);
2238 lx = dx * (TILE_BORDER-1);
2239 ly = dy * (TILE_BORDER-1);
2243 if (angle == 0.0 && (tile & dir)) {
2245 * If we are fully connected to the other tile, we must
2246 * draw right across the tile border. (We can use our
2247 * own ACTIVE state to determine what colour to do this
2248 * in: if we are fully connected to the other tile then
2249 * the two ACTIVE states will be the same.)
2251 draw_rect_coords(fe, px-vx, py-vy, px+lx+vx, py+ly+vy, COL_WIRE);
2252 draw_rect_coords(fe, px, py, px+lx, py+ly,
2253 (tile & ACTIVE) ? COL_POWERED : COL_WIRE);
2256 * The other tile extends into our border, but isn't
2257 * actually connected to us. Just draw a single black
2260 draw_rect_coords(fe, px, py, px, py, COL_WIRE);
2265 * Draw barrier corners, and then barriers.
2267 for (phase = 0; phase < 2; phase++) {
2268 for (dir = 1; dir < 0x10; dir <<= 1)
2269 if (barrier(state, x, y) & (dir << 4))
2270 draw_barrier_corner(fe, x, y, dir << 4, phase);
2271 for (dir = 1; dir < 0x10; dir <<= 1)
2272 if (barrier(state, x, y) & dir)
2273 draw_barrier(fe, x, y, dir, phase);
2276 draw_update(fe, bx, by, TILE_SIZE+TILE_BORDER, TILE_SIZE+TILE_BORDER);
2279 static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate,
2280 game_state *state, int dir, game_ui *ui, float t, float ft)
2282 int x, y, tx, ty, frame, last_rotate_dir;
2283 unsigned char *active;
2287 * Clear the screen and draw the exterior barrier lines if this
2288 * is our first call.
2296 WINDOW_OFFSET * 2 + TILE_SIZE * state->width + TILE_BORDER,
2297 WINDOW_OFFSET * 2 + TILE_SIZE * state->height + TILE_BORDER,
2299 draw_update(fe, 0, 0,
2300 WINDOW_OFFSET*2 + TILE_SIZE*state->width + TILE_BORDER,
2301 WINDOW_OFFSET*2 + TILE_SIZE*state->height + TILE_BORDER);
2303 for (phase = 0; phase < 2; phase++) {
2305 for (x = 0; x < ds->width; x++) {
2306 if (barrier(state, x, 0) & UL)
2307 draw_barrier_corner(fe, x, -1, LD, phase);
2308 if (barrier(state, x, 0) & RU)
2309 draw_barrier_corner(fe, x, -1, DR, phase);
2310 if (barrier(state, x, 0) & U)
2311 draw_barrier(fe, x, -1, D, phase);
2312 if (barrier(state, x, ds->height-1) & DR)
2313 draw_barrier_corner(fe, x, ds->height, RU, phase);
2314 if (barrier(state, x, ds->height-1) & LD)
2315 draw_barrier_corner(fe, x, ds->height, UL, phase);
2316 if (barrier(state, x, ds->height-1) & D)
2317 draw_barrier(fe, x, ds->height, U, phase);
2320 for (y = 0; y < ds->height; y++) {
2321 if (barrier(state, 0, y) & UL)
2322 draw_barrier_corner(fe, -1, y, RU, phase);
2323 if (barrier(state, 0, y) & LD)
2324 draw_barrier_corner(fe, -1, y, DR, phase);
2325 if (barrier(state, 0, y) & L)
2326 draw_barrier(fe, -1, y, R, phase);
2327 if (barrier(state, ds->width-1, y) & RU)
2328 draw_barrier_corner(fe, ds->width, y, UL, phase);
2329 if (barrier(state, ds->width-1, y) & DR)
2330 draw_barrier_corner(fe, ds->width, y, LD, phase);
2331 if (barrier(state, ds->width-1, y) & R)
2332 draw_barrier(fe, ds->width, y, L, phase);
2338 last_rotate_dir = dir==-1 ? oldstate->last_rotate_dir :
2339 state->last_rotate_dir;
2340 if (oldstate && (t < ROTATE_TIME) && last_rotate_dir) {
2342 * We're animating a single tile rotation. Find the turning
2345 tx = (dir==-1 ? oldstate->last_rotate_x : state->last_rotate_x);
2346 ty = (dir==-1 ? oldstate->last_rotate_y : state->last_rotate_y);
2347 angle = last_rotate_dir * dir * 90.0F * (t / ROTATE_TIME);
2354 * We're animating a completion flash. Find which frame
2357 frame = (int)(ft / FLASH_FRAME);
2361 * Draw any tile which differs from the way it was last drawn.
2363 active = compute_active(state);
2365 for (x = 0; x < ds->width; x++)
2366 for (y = 0; y < ds->height; y++) {
2367 unsigned char c = tile(state, x, y) | index(state, active, x, y);
2370 * In a completion flash, we adjust the LOCKED bit
2371 * depending on our distance from the centre point and
2375 int xdist, ydist, dist;
2376 xdist = (x < state->cx ? state->cx - x : x - state->cx);
2377 ydist = (y < state->cy ? state->cy - y : y - state->cy);
2378 dist = (xdist > ydist ? xdist : ydist);
2380 if (frame >= dist && frame < dist+4) {
2381 int lock = (frame - dist) & 1;
2382 lock = lock ? LOCKED : 0;
2383 c = (c &~ LOCKED) | lock;
2387 if (index(state, ds->visible, x, y) != c ||
2388 index(state, ds->visible, x, y) == 0xFF ||
2389 (x == tx && y == ty) ||
2390 (ui->cur_visible && x == ui->cur_x && y == ui->cur_y)) {
2391 draw_tile(fe, state, x, y, c,
2392 (x == tx && y == ty ? angle : 0.0F),
2393 (ui->cur_visible && x == ui->cur_x && y == ui->cur_y));
2394 if ((x == tx && y == ty) ||
2395 (ui->cur_visible && x == ui->cur_x && y == ui->cur_y))
2396 index(state, ds->visible, x, y) = 0xFF;
2398 index(state, ds->visible, x, y) = c;
2403 * Update the status bar.
2406 char statusbuf[256];
2409 n = state->width * state->height;
2410 for (i = a = n2 = 0; i < n; i++) {
2413 if (state->tiles[i] & 0xF)
2417 sprintf(statusbuf, "%sActive: %d/%d",
2418 (state->used_solve ? "Auto-solved. " :
2419 state->completed ? "COMPLETED! " : ""), a, n2);
2421 status_bar(fe, statusbuf);
2427 static float game_anim_length(game_state *oldstate,
2428 game_state *newstate, int dir)
2430 int last_rotate_dir;
2433 * Don't animate an auto-solve move.
2435 if ((dir > 0 && newstate->just_used_solve) ||
2436 (dir < 0 && oldstate->just_used_solve))
2440 * Don't animate if last_rotate_dir is zero.
2442 last_rotate_dir = dir==-1 ? oldstate->last_rotate_dir :
2443 newstate->last_rotate_dir;
2444 if (last_rotate_dir)
2450 static float game_flash_length(game_state *oldstate,
2451 game_state *newstate, int dir)
2454 * If the game has just been completed, we display a completion
2457 if (!oldstate->completed && newstate->completed &&
2458 !oldstate->used_solve && !newstate->used_solve) {
2461 if (size < newstate->cx+1)
2462 size = newstate->cx+1;
2463 if (size < newstate->cy+1)
2464 size = newstate->cy+1;
2465 if (size < newstate->width - newstate->cx)
2466 size = newstate->width - newstate->cx;
2467 if (size < newstate->height - newstate->cy)
2468 size = newstate->height - newstate->cy;
2469 return FLASH_FRAME * (size+4);
2475 static int game_wants_statusbar(void)
2484 const struct game thegame = {
2492 TRUE, game_configure, custom_params,
2501 FALSE, game_text_format,
2508 game_free_drawstate,
2512 game_wants_statusbar,