16 * The standard user interface for Net simply has left- and
17 * right-button mouse clicks in a square rotate it one way or the
18 * other. We also provide, by #ifdef, a separate interface based on
19 * rotational dragging motions. I initially developed this for the
20 * Mac on the basis that it might work better than the click
21 * interface with only one mouse button available, but in fact
22 * found it to be quite strange and unintuitive. Apparently it
23 * works better on stylus-driven platforms such as Palm and
24 * PocketPC, though, so we enable it by default there.
30 #define MATMUL(xr,yr,m,x,y) do { \
31 float rx, ry, xx = (x), yy = (y), *mat = (m); \
32 rx = mat[0] * xx + mat[2] * yy; \
33 ry = mat[1] * xx + mat[3] * yy; \
34 (xr) = rx; (yr) = ry; \
37 /* Direction and other bitfields */
45 /* Rotations: Anticlockwise, Clockwise, Flip, general rotate */
46 #define A(x) ( (((x) & 0x07) << 1) | (((x) & 0x08) >> 3) )
47 #define C(x) ( (((x) & 0x0E) >> 1) | (((x) & 0x01) << 3) )
48 #define F(x) ( (((x) & 0x0C) >> 2) | (((x) & 0x03) << 2) )
49 #define ROT(x, n) ( ((n)&3) == 0 ? (x) : \
50 ((n)&3) == 1 ? A(x) : \
51 ((n)&3) == 2 ? F(x) : C(x) )
53 /* X and Y displacements */
54 #define X(x) ( (x) == R ? +1 : (x) == L ? -1 : 0 )
55 #define Y(x) ( (x) == D ? +1 : (x) == U ? -1 : 0 )
58 #define COUNT(x) ( (((x) & 0x08) >> 3) + (((x) & 0x04) >> 2) + \
59 (((x) & 0x02) >> 1) + ((x) & 0x01) )
61 #define PREFERRED_TILE_SIZE 32
62 #define TILE_SIZE (ds->tilesize)
65 #define WINDOW_OFFSET 4
67 #define WINDOW_OFFSET 16
70 #define ROTATE_TIME 0.13F
71 #define FLASH_FRAME 0.07F
73 /* Transform physical coords to game coords using game_drawstate ds */
74 #define GX(x) (((x) + ds->org_x) % ds->width)
75 #define GY(y) (((y) + ds->org_y) % ds->height)
76 /* ...and game coords to physical coords */
77 #define RX(x) (((x) + ds->width - ds->org_x) % ds->width)
78 #define RY(y) (((y) + ds->height - ds->org_y) % ds->height)
96 float barrier_probability;
100 int width, height, wrapping, completed;
101 int last_rotate_x, last_rotate_y, last_rotate_dir;
103 unsigned char *tiles;
104 unsigned char *barriers;
107 #define OFFSETWH(x2,y2,x1,y1,dir,width,height) \
108 ( (x2) = ((x1) + width + X((dir))) % width, \
109 (y2) = ((y1) + height + Y((dir))) % height)
111 #define OFFSET(x2,y2,x1,y1,dir,state) \
112 OFFSETWH(x2,y2,x1,y1,dir,(state)->width,(state)->height)
114 #define index(state, a, x, y) ( a[(y) * (state)->width + (x)] )
115 #define tile(state, x, y) index(state, (state)->tiles, x, y)
116 #define barrier(state, x, y) index(state, (state)->barriers, x, y)
122 static int xyd_cmp(const void *av, const void *bv) {
123 const struct xyd *a = (const struct xyd *)av;
124 const struct xyd *b = (const struct xyd *)bv;
133 if (a->direction < b->direction)
135 if (a->direction > b->direction)
140 static int xyd_cmp_nc(void *av, void *bv) { return xyd_cmp(av, bv); }
142 static struct xyd *new_xyd(int x, int y, int direction)
144 struct xyd *xyd = snew(struct xyd);
147 xyd->direction = direction;
151 /* ----------------------------------------------------------------------
152 * Manage game parameters.
154 static game_params *default_params(void)
156 game_params *ret = snew(game_params);
160 ret->wrapping = FALSE;
162 ret->barrier_probability = 0.0;
167 static const struct game_params net_presets[] = {
168 {5, 5, FALSE, TRUE, 0.0},
169 {7, 7, FALSE, TRUE, 0.0},
170 {9, 9, FALSE, TRUE, 0.0},
171 {11, 11, FALSE, TRUE, 0.0},
173 {13, 11, FALSE, TRUE, 0.0},
175 {5, 5, TRUE, TRUE, 0.0},
176 {7, 7, TRUE, TRUE, 0.0},
177 {9, 9, TRUE, TRUE, 0.0},
178 {11, 11, TRUE, TRUE, 0.0},
180 {13, 11, TRUE, TRUE, 0.0},
184 static int game_fetch_preset(int i, char **name, game_params **params)
189 if (i < 0 || i >= lenof(net_presets))
192 ret = snew(game_params);
193 *ret = net_presets[i];
195 sprintf(str, "%dx%d%s", ret->width, ret->height,
196 ret->wrapping ? " wrapping" : "");
203 static void free_params(game_params *params)
208 static game_params *dup_params(const game_params *params)
210 game_params *ret = snew(game_params);
211 *ret = *params; /* structure copy */
215 static void decode_params(game_params *ret, char const *string)
217 char const *p = string;
219 ret->width = atoi(p);
220 while (*p && isdigit((unsigned char)*p)) p++;
223 ret->height = atoi(p);
224 while (*p && isdigit((unsigned char)*p)) p++;
226 ret->height = ret->width;
232 ret->wrapping = TRUE;
233 } else if (*p == 'b') {
235 ret->barrier_probability = (float)atof(p);
236 while (*p && (*p == '.' || isdigit((unsigned char)*p))) p++;
237 } else if (*p == 'a') {
241 p++; /* skip any other gunk */
245 static char *encode_params(const game_params *params, int full)
250 len = sprintf(ret, "%dx%d", params->width, params->height);
251 if (params->wrapping)
253 if (full && params->barrier_probability)
254 len += sprintf(ret+len, "b%g", params->barrier_probability);
255 if (full && !params->unique)
257 assert(len < lenof(ret));
263 static config_item *game_configure(const game_params *params)
268 ret = snewn(6, config_item);
270 ret[0].name = "Width";
271 ret[0].type = C_STRING;
272 sprintf(buf, "%d", params->width);
273 ret[0].sval = dupstr(buf);
276 ret[1].name = "Height";
277 ret[1].type = C_STRING;
278 sprintf(buf, "%d", params->height);
279 ret[1].sval = dupstr(buf);
282 ret[2].name = "Walls wrap around";
283 ret[2].type = C_BOOLEAN;
285 ret[2].ival = params->wrapping;
287 ret[3].name = "Barrier probability";
288 ret[3].type = C_STRING;
289 sprintf(buf, "%g", params->barrier_probability);
290 ret[3].sval = dupstr(buf);
293 ret[4].name = "Ensure unique solution";
294 ret[4].type = C_BOOLEAN;
296 ret[4].ival = params->unique;
306 static game_params *custom_params(const config_item *cfg)
308 game_params *ret = snew(game_params);
310 ret->width = atoi(cfg[0].sval);
311 ret->height = atoi(cfg[1].sval);
312 ret->wrapping = cfg[2].ival;
313 ret->barrier_probability = (float)atof(cfg[3].sval);
314 ret->unique = cfg[4].ival;
319 static char *validate_params(const game_params *params, int full)
321 if (params->width <= 0 || params->height <= 0)
322 return "Width and height must both be greater than zero";
323 if (params->width <= 1 && params->height <= 1)
324 return "At least one of width and height must be greater than one";
325 if (params->barrier_probability < 0)
326 return "Barrier probability may not be negative";
327 if (params->barrier_probability > 1)
328 return "Barrier probability may not be greater than 1";
331 * Specifying either grid dimension as 2 in a wrapping puzzle
332 * makes it actually impossible to ensure a unique puzzle
337 * Without loss of generality, let us assume the puzzle _width_
338 * is 2, so we can conveniently discuss rows without having to
339 * say `rows/columns' all the time. (The height may be 2 as
340 * well, but that doesn't matter.)
342 * In each row, there are two edges between tiles: the inner
343 * edge (running down the centre of the grid) and the outer
344 * edge (the identified left and right edges of the grid).
346 * Lemma: In any valid 2xn puzzle there must be at least one
347 * row in which _exactly one_ of the inner edge and outer edge
350 * Proof: No row can have _both_ inner and outer edges
351 * connected, because this would yield a loop. So the only
352 * other way to falsify the lemma is for every row to have
353 * _neither_ the inner nor outer edge connected. But this
354 * means there is no connection at all between the left and
355 * right columns of the puzzle, so there are two disjoint
356 * subgraphs, which is also disallowed. []
358 * Given such a row, it is always possible to make the
359 * disconnected edge connected and the connected edge
360 * disconnected without changing the state of any other edge.
361 * (This is easily seen by case analysis on the various tiles:
362 * left-pointing and right-pointing endpoints can be exchanged,
363 * likewise T-pieces, and a corner piece can select its
364 * horizontal connectivity independently of its vertical.) This
365 * yields a distinct valid solution.
367 * Thus, for _every_ row in which exactly one of the inner and
368 * outer edge is connected, there are two valid states for that
369 * row, and hence the total number of solutions of the puzzle
370 * is at least 2^(number of such rows), and in particular is at
371 * least 2 since there must be at least one such row. []
373 if (full && params->unique && params->wrapping &&
374 (params->width == 2 || params->height == 2))
375 return "No wrapping puzzle with a width or height of 2 can have"
376 " a unique solution";
381 /* ----------------------------------------------------------------------
382 * Solver used to assure solution uniqueness during generation.
386 * Test cases I used while debugging all this were
388 * ./net --generate 1 13x11w#12300
389 * which expands under the non-unique grid generation rules to
390 * 13x11w:5eaade1bd222664436d5e2965c12656b1129dd825219e3274d558d5eb2dab5da18898e571d5a2987be79746bd95726c597447d6da96188c513add829da7681da954db113d3cd244
391 * and has two ambiguous areas.
393 * An even better one is
394 * 13x11w#507896411361192
396 * 13x11w:b7125b1aec598eb31bd58d82572bc11494e5dee4e8db2bdd29b88d41a16bdd996d2996ddec8c83741a1e8674e78328ba71737b8894a9271b1cd1399453d1952e43951d9b712822e
397 * and has an ambiguous area _and_ a situation where loop avoidance
398 * is a necessary deductive technique.
401 * 48x25w#820543338195187
403 * 48x25w:255989d14cdd185deaa753a93821a12edc1ab97943ac127e2685d7b8b3c48861b2192416139212b316eddd35de43714ebc7628d753db32e596284d9ec52c5a7dc1b4c811a655117d16dc28921b2b4161352cab1d89d18bc836b8b891d55ea4622a1251861b5bc9a8aa3e5bcd745c95229ca6c3b5e21d5832d397e917325793d7eb442dc351b2db2a52ba8e1651642275842d8871d5534aabc6d5b741aaa2d48ed2a7dbbb3151ddb49d5b9a7ed1ab98ee75d613d656dbba347bc514c84556b43a9bc65a3256ead792488b862a9d2a8a39b4255a4949ed7dbd79443292521265896b4399c95ede89d7c8c797a6a57791a849adea489359a158aa12e5dacce862b8333b7ebea7d344d1a3c53198864b73a9dedde7b663abb1b539e1e8853b1b7edb14a2a17ebaae4dbe63598a2e7e9a2dbdad415bc1d8cb88cbab5a8c82925732cd282e641ea3bd7d2c6e776de9117a26be86deb7c82c89524b122cb9397cd1acd2284e744ea62b9279bae85479ababe315c3ac29c431333395b24e6a1e3c43a2da42d4dce84aadd5b154aea555eaddcbd6e527d228c19388d9b424d94214555a7edbdeebe569d4a56dc51a86bd9963e377bb74752bd5eaa5761ba545e297b62a1bda46ab4aee423ad6c661311783cc18786d4289236563cb4a75ec67d481c14814994464cd1b87396dee63e5ab6e952cc584baa1d4c47cb557ec84dbb63d487c8728118673a166846dd3a4ebc23d6cb9c5827d96b4556e91899db32b517eda815ae271a8911bd745447121dc8d321557bc2a435ebec1bbac35b1a291669451174e6aa2218a4a9c5a6ca31ebc45d84e3a82c121e9ced7d55e9a
404 * which has a spot (far right) where slightly more complex loop
405 * avoidance is required.
409 unsigned char *marked;
415 static struct todo *todo_new(int maxsize)
417 struct todo *todo = snew(struct todo);
418 todo->marked = snewn(maxsize, unsigned char);
419 memset(todo->marked, 0, maxsize);
420 todo->buflen = maxsize + 1;
421 todo->buffer = snewn(todo->buflen, int);
422 todo->head = todo->tail = 0;
426 static void todo_free(struct todo *todo)
433 static void todo_add(struct todo *todo, int index)
435 if (todo->marked[index])
436 return; /* already on the list */
437 todo->marked[index] = TRUE;
438 todo->buffer[todo->tail++] = index;
439 if (todo->tail == todo->buflen)
443 static int todo_get(struct todo *todo) {
446 if (todo->head == todo->tail)
447 return -1; /* list is empty */
448 ret = todo->buffer[todo->head++];
449 if (todo->head == todo->buflen)
451 todo->marked[ret] = FALSE;
456 static int net_solver(int w, int h, unsigned char *tiles,
457 unsigned char *barriers, int wrapping)
459 unsigned char *tilestate;
460 unsigned char *edgestate;
469 * Set up the solver's data structures.
473 * tilestate stores the possible orientations of each tile.
474 * There are up to four of these, so we'll index the array in
475 * fours. tilestate[(y * w + x) * 4] and its three successive
476 * members give the possible orientations, clearing to 255 from
477 * the end as things are ruled out.
479 * In this loop we also count up the area of the grid (which is
480 * not _necessarily_ equal to w*h, because there might be one
481 * or more blank squares present. This will never happen in a
482 * grid generated _by_ this program, but it's worth keeping the
483 * solver as general as possible.)
485 tilestate = snewn(w * h * 4, unsigned char);
487 for (i = 0; i < w*h; i++) {
488 tilestate[i * 4] = tiles[i] & 0xF;
489 for (j = 1; j < 4; j++) {
490 if (tilestate[i * 4 + j - 1] == 255 ||
491 A(tilestate[i * 4 + j - 1]) == tilestate[i * 4])
492 tilestate[i * 4 + j] = 255;
494 tilestate[i * 4 + j] = A(tilestate[i * 4 + j - 1]);
501 * edgestate stores the known state of each edge. It is 0 for
502 * unknown, 1 for open (connected) and 2 for closed (not
505 * In principle we need only worry about each edge once each,
506 * but in fact it's easier to track each edge twice so that we
507 * can reference it from either side conveniently. Also I'm
508 * going to allocate _five_ bytes per tile, rather than the
509 * obvious four, so that I can index edgestate[(y*w+x) * 5 + d]
510 * where d is 1,2,4,8 and they never overlap.
512 edgestate = snewn((w * h - 1) * 5 + 9, unsigned char);
513 memset(edgestate, 0, (w * h - 1) * 5 + 9);
516 * deadends tracks which edges have dead ends on them. It is
517 * indexed by tile and direction: deadends[(y*w+x) * 5 + d]
518 * tells you whether heading out of tile (x,y) in direction d
519 * can reach a limited amount of the grid. Values are area+1
520 * (no dead end known) or less than that (can reach _at most_
521 * this many other tiles by heading this way out of this tile).
523 deadends = snewn((w * h - 1) * 5 + 9, int);
524 for (i = 0; i < (w * h - 1) * 5 + 9; i++)
525 deadends[i] = area+1;
528 * equivalence tracks which sets of tiles are known to be
529 * connected to one another, so we can avoid creating loops by
530 * linking together tiles which are already linked through
533 * This is a disjoint set forest structure: equivalence[i]
534 * contains the index of another member of the equivalence
535 * class containing i, or contains i itself for precisely one
536 * member in each such class. To find a representative member
537 * of the equivalence class containing i, you keep replacing i
538 * with equivalence[i] until it stops changing; then you go
539 * _back_ along the same path and point everything on it
540 * directly at the representative member so as to speed up
541 * future searches. Then you test equivalence between tiles by
542 * finding the representative of each tile and seeing if
543 * they're the same; and you create new equivalence (merge
544 * classes) by finding the representative of each tile and
545 * setting equivalence[one]=the_other.
547 equivalence = snew_dsf(w * h);
550 * On a non-wrapping grid, we instantly know that all the edges
551 * round the edge are closed.
554 for (i = 0; i < w; i++) {
555 edgestate[i * 5 + 2] = edgestate[((h-1) * w + i) * 5 + 8] = 2;
557 for (i = 0; i < h; i++) {
558 edgestate[(i * w + w-1) * 5 + 1] = edgestate[(i * w) * 5 + 4] = 2;
563 * If we have barriers available, we can mark those edges as
567 for (y = 0; y < h; y++) for (x = 0; x < w; x++) {
569 for (d = 1; d <= 8; d += d) {
570 if (barriers[y*w+x] & d) {
573 * In principle the barrier list should already
574 * contain each barrier from each side, but
575 * let's not take chances with our internal
578 OFFSETWH(x2, y2, x, y, d, w, h);
579 edgestate[(y*w+x) * 5 + d] = 2;
580 edgestate[(y2*w+x2) * 5 + F(d)] = 2;
587 * Since most deductions made by this solver are local (the
588 * exception is loop avoidance, where joining two tiles
589 * together on one side of the grid can theoretically permit a
590 * fresh deduction on the other), we can address the scaling
591 * problem inherent in iterating repeatedly over the entire
592 * grid by instead working with a to-do list.
594 todo = todo_new(w * h);
597 * Main deductive loop.
599 done_something = TRUE; /* prevent instant termination! */
604 * Take a tile index off the todo list and process it.
606 index = todo_get(todo);
609 * If we have run out of immediate things to do, we
610 * have no choice but to scan the whole grid for
611 * longer-range things we've missed. Hence, I now add
612 * every square on the grid back on to the to-do list.
613 * I also set `done_something' to FALSE at this point;
614 * if we later come back here and find it still FALSE,
615 * we will know we've scanned the entire grid without
616 * finding anything new to do, and we can terminate.
620 for (i = 0; i < w*h; i++)
622 done_something = FALSE;
624 index = todo_get(todo);
630 int d, ourclass = dsf_canonify(equivalence, y*w+x);
633 deadendmax[1] = deadendmax[2] = deadendmax[4] = deadendmax[8] = 0;
635 for (i = j = 0; i < 4 && tilestate[(y*w+x) * 4 + i] != 255; i++) {
637 int nnondeadends, nondeadends[4], deadendtotal;
638 int nequiv, equiv[5];
639 int val = tilestate[(y*w+x) * 4 + i];
642 nnondeadends = deadendtotal = 0;
645 for (d = 1; d <= 8; d += d) {
647 * Immediately rule out this orientation if it
648 * conflicts with any known edge.
650 if ((edgestate[(y*w+x) * 5 + d] == 1 && !(val & d)) ||
651 (edgestate[(y*w+x) * 5 + d] == 2 && (val & d)))
656 * Count up the dead-end statistics.
658 if (deadends[(y*w+x) * 5 + d] <= area) {
659 deadendtotal += deadends[(y*w+x) * 5 + d];
661 nondeadends[nnondeadends++] = d;
665 * Ensure we aren't linking to any tiles,
666 * through edges not already known to be
667 * open, which create a loop.
669 if (edgestate[(y*w+x) * 5 + d] == 0) {
672 OFFSETWH(x2, y2, x, y, d, w, h);
673 c = dsf_canonify(equivalence, y2*w+x2);
674 for (k = 0; k < nequiv; k++)
685 if (nnondeadends == 0) {
687 * If this orientation links together dead-ends
688 * with a total area of less than the entire
689 * grid, it is invalid.
691 * (We add 1 to deadendtotal because of the
692 * tile itself, of course; one tile linking
693 * dead ends of size 2 and 3 forms a subnetwork
694 * with a total area of 6, not 5.)
696 if (deadendtotal > 0 && deadendtotal+1 < area)
698 } else if (nnondeadends == 1) {
700 * If this orientation links together one or
701 * more dead-ends with precisely one
702 * non-dead-end, then we may have to mark that
703 * non-dead-end as a dead end going the other
704 * way. However, it depends on whether all
705 * other orientations share the same property.
708 if (deadendmax[nondeadends[0]] < deadendtotal)
709 deadendmax[nondeadends[0]] = deadendtotal;
712 * If this orientation links together two or
713 * more non-dead-ends, then we can rule out the
714 * possibility of putting in new dead-end
715 * markings in those directions.
718 for (k = 0; k < nnondeadends; k++)
719 deadendmax[nondeadends[k]] = area+1;
723 tilestate[(y*w+x) * 4 + j++] = val;
724 #ifdef SOLVER_DIAGNOSTICS
726 printf("ruling out orientation %x at %d,%d\n", val, x, y);
730 assert(j > 0); /* we can't lose _all_ possibilities! */
733 done_something = TRUE;
736 * We have ruled out at least one tile orientation.
737 * Make sure the rest are blanked.
740 tilestate[(y*w+x) * 4 + j++] = 255;
744 * Now go through the tile orientations again and see
745 * if we've deduced anything new about any edges.
751 for (i = 0; i < 4 && tilestate[(y*w+x) * 4 + i] != 255; i++) {
752 a &= tilestate[(y*w+x) * 4 + i];
753 o |= tilestate[(y*w+x) * 4 + i];
755 for (d = 1; d <= 8; d += d)
756 if (edgestate[(y*w+x) * 5 + d] == 0) {
758 OFFSETWH(x2, y2, x, y, d, w, h);
761 /* This edge is open in all orientations. */
762 #ifdef SOLVER_DIAGNOSTICS
763 printf("marking edge %d,%d:%d open\n", x, y, d);
765 edgestate[(y*w+x) * 5 + d] = 1;
766 edgestate[(y2*w+x2) * 5 + d2] = 1;
767 dsf_merge(equivalence, y*w+x, y2*w+x2);
768 done_something = TRUE;
769 todo_add(todo, y2*w+x2);
770 } else if (!(o & d)) {
771 /* This edge is closed in all orientations. */
772 #ifdef SOLVER_DIAGNOSTICS
773 printf("marking edge %d,%d:%d closed\n", x, y, d);
775 edgestate[(y*w+x) * 5 + d] = 2;
776 edgestate[(y2*w+x2) * 5 + d2] = 2;
777 done_something = TRUE;
778 todo_add(todo, y2*w+x2);
785 * Now check the dead-end markers and see if any of
786 * them has lowered from the real ones.
788 for (d = 1; d <= 8; d += d) {
790 OFFSETWH(x2, y2, x, y, d, w, h);
792 if (deadendmax[d] > 0 &&
793 deadends[(y2*w+x2) * 5 + d2] > deadendmax[d]) {
794 #ifdef SOLVER_DIAGNOSTICS
795 printf("setting dead end value %d,%d:%d to %d\n",
796 x2, y2, d2, deadendmax[d]);
798 deadends[(y2*w+x2) * 5 + d2] = deadendmax[d];
799 done_something = TRUE;
800 todo_add(todo, y2*w+x2);
808 * Mark all completely determined tiles as locked.
811 for (i = 0; i < w*h; i++) {
812 if (tilestate[i * 4 + 1] == 255) {
813 assert(tilestate[i * 4 + 0] != 255);
814 tiles[i] = tilestate[i * 4] | LOCKED;
822 * Free up working space.
833 /* ----------------------------------------------------------------------
834 * Randomly select a new game description.
838 * Function to randomly perturb an ambiguous section in a grid, to
839 * attempt to ensure unique solvability.
841 static void perturb(int w, int h, unsigned char *tiles, int wrapping,
842 random_state *rs, int startx, int starty, int startd)
844 struct xyd *perimeter, *perim2, *loop[2], looppos[2];
845 int nperim, perimsize, nloop[2], loopsize[2];
849 * We know that the tile at (startx,starty) is part of an
850 * ambiguous section, and we also know that its neighbour in
851 * direction startd is fully specified. We begin by tracing all
852 * the way round the ambiguous area.
854 nperim = perimsize = 0;
859 #ifdef PERTURB_DIAGNOSTICS
860 printf("perturb %d,%d:%d\n", x, y, d);
865 if (nperim >= perimsize) {
866 perimsize = perimsize * 3 / 2 + 32;
867 perimeter = sresize(perimeter, perimsize, struct xyd);
869 perimeter[nperim].x = x;
870 perimeter[nperim].y = y;
871 perimeter[nperim].direction = d;
873 #ifdef PERTURB_DIAGNOSTICS
874 printf("perimeter: %d,%d:%d\n", x, y, d);
878 * First, see if we can simply turn left from where we are
879 * and find another locked square.
882 OFFSETWH(x2, y2, x, y, d2, w, h);
883 if ((!wrapping && (abs(x2-x) > 1 || abs(y2-y) > 1)) ||
884 (tiles[y2*w+x2] & LOCKED)) {
888 * Failing that, step left into the new square and look
893 OFFSETWH(x2, y2, x, y, d, w, h);
894 if ((wrapping || (abs(x2-x) <= 1 && abs(y2-y) <= 1)) &&
895 !(tiles[y2*w+x2] & LOCKED)) {
897 * And failing _that_, we're going to have to step
898 * forward into _that_ square and look right at the
899 * same locked square as we started with.
907 } while (x != startx || y != starty || d != startd);
910 * Our technique for perturbing this ambiguous area is to
911 * search round its edge for a join we can make: that is, an
912 * edge on the perimeter which is (a) not currently connected,
913 * and (b) connecting it would not yield a full cross on either
914 * side. Then we make that join, search round the network to
915 * find the loop thus constructed, and sever the loop at a
916 * randomly selected other point.
918 perim2 = snewn(nperim, struct xyd);
919 memcpy(perim2, perimeter, nperim * sizeof(struct xyd));
920 /* Shuffle the perimeter, so as to search it without directional bias. */
921 shuffle(perim2, nperim, sizeof(*perim2), rs);
922 for (i = 0; i < nperim; i++) {
927 d = perim2[i].direction;
929 OFFSETWH(x2, y2, x, y, d, w, h);
930 if (!wrapping && (abs(x2-x) > 1 || abs(y2-y) > 1))
931 continue; /* can't link across non-wrapping border */
932 if (tiles[y*w+x] & d)
933 continue; /* already linked in this direction! */
934 if (((tiles[y*w+x] | d) & 15) == 15)
935 continue; /* can't turn this tile into a cross */
936 if (((tiles[y2*w+x2] | F(d)) & 15) == 15)
937 continue; /* can't turn other tile into a cross */
940 * We've found the point at which we're going to make a new
943 #ifdef PERTURB_DIAGNOSTICS
944 printf("linking %d,%d:%d\n", x, y, d);
947 tiles[y2*w+x2] |= F(d);
955 return; /* nothing we can do! */
959 * Now we've constructed a new link, we need to find the entire
960 * loop of which it is a part.
962 * In principle, this involves doing a complete search round
963 * the network. However, I anticipate that in the vast majority
964 * of cases the loop will be quite small, so what I'm going to
965 * do is make _two_ searches round the network in parallel, one
966 * keeping its metaphorical hand on the left-hand wall while
967 * the other keeps its hand on the right. As soon as one of
968 * them gets back to its starting point, I abandon the other.
970 for (i = 0; i < 2; i++) {
971 loopsize[i] = nloop[i] = 0;
975 looppos[i].direction = d;
978 for (i = 0; i < 2; i++) {
983 d = looppos[i].direction;
985 OFFSETWH(x2, y2, x, y, d, w, h);
988 * Add this path segment to the loop, unless it exactly
989 * reverses the previous one on the loop in which case
990 * we take it away again.
992 #ifdef PERTURB_DIAGNOSTICS
993 printf("looppos[%d] = %d,%d:%d\n", i, x, y, d);
996 loop[i][nloop[i]-1].x == x2 &&
997 loop[i][nloop[i]-1].y == y2 &&
998 loop[i][nloop[i]-1].direction == F(d)) {
999 #ifdef PERTURB_DIAGNOSTICS
1000 printf("removing path segment %d,%d:%d from loop[%d]\n",
1005 if (nloop[i] >= loopsize[i]) {
1006 loopsize[i] = loopsize[i] * 3 / 2 + 32;
1007 loop[i] = sresize(loop[i], loopsize[i], struct xyd);
1009 #ifdef PERTURB_DIAGNOSTICS
1010 printf("adding path segment %d,%d:%d to loop[%d]\n",
1013 loop[i][nloop[i]++] = looppos[i];
1016 #ifdef PERTURB_DIAGNOSTICS
1017 printf("tile at new location is %x\n", tiles[y2*w+x2] & 0xF);
1020 for (j = 0; j < 4; j++) {
1025 #ifdef PERTURB_DIAGNOSTICS
1026 printf("trying dir %d\n", d);
1028 if (tiles[y2*w+x2] & d) {
1031 looppos[i].direction = d;
1037 assert(nloop[i] > 0);
1039 if (looppos[i].x == loop[i][0].x &&
1040 looppos[i].y == loop[i][0].y &&
1041 looppos[i].direction == loop[i][0].direction) {
1042 #ifdef PERTURB_DIAGNOSTICS
1043 printf("loop %d finished tracking\n", i);
1047 * Having found our loop, we now sever it at a
1048 * randomly chosen point - absolutely any will do -
1049 * which is not the one we joined it at to begin
1050 * with. Conveniently, the one we joined it at is
1051 * loop[i][0], so we just avoid that one.
1053 j = random_upto(rs, nloop[i]-1) + 1;
1056 d = loop[i][j].direction;
1057 OFFSETWH(x2, y2, x, y, d, w, h);
1059 tiles[y2*w+x2] &= ~F(d);
1071 * Finally, we must mark the entire disputed section as locked,
1072 * to prevent the perturb function being called on it multiple
1075 * To do this, we _sort_ the perimeter of the area. The
1076 * existing xyd_cmp function will arrange things into columns
1077 * for us, in such a way that each column has the edges in
1078 * vertical order. Then we can work down each column and fill
1079 * in all the squares between an up edge and a down edge.
1081 qsort(perimeter, nperim, sizeof(struct xyd), xyd_cmp);
1083 for (i = 0; i <= nperim; i++) {
1084 if (i == nperim || perimeter[i].x > x) {
1086 * Fill in everything from the last Up edge to the
1087 * bottom of the grid, if necessary.
1091 #ifdef PERTURB_DIAGNOSTICS
1092 printf("resolved: locking tile %d,%d\n", x, y);
1094 tiles[y * w + x] |= LOCKED;
1107 if (perimeter[i].direction == U) {
1110 } else if (perimeter[i].direction == D) {
1112 * Fill in everything from the last Up edge to here.
1114 assert(x == perimeter[i].x && y <= perimeter[i].y);
1115 while (y <= perimeter[i].y) {
1116 #ifdef PERTURB_DIAGNOSTICS
1117 printf("resolved: locking tile %d,%d\n", x, y);
1119 tiles[y * w + x] |= LOCKED;
1129 static char *new_game_desc(const game_params *params, random_state *rs,
1130 char **aux, int interactive)
1132 tree234 *possibilities, *barriertree;
1133 int w, h, x, y, cx, cy, nbarriers;
1134 unsigned char *tiles, *barriers;
1143 tiles = snewn(w * h, unsigned char);
1144 barriers = snewn(w * h, unsigned char);
1148 memset(tiles, 0, w * h);
1149 memset(barriers, 0, w * h);
1152 * Construct the unshuffled grid.
1154 * To do this, we simply start at the centre point, repeatedly
1155 * choose a random possibility out of the available ways to
1156 * extend a used square into an unused one, and do it. After
1157 * extending the third line out of a square, we remove the
1158 * fourth from the possibilities list to avoid any full-cross
1159 * squares (which would make the game too easy because they
1160 * only have one orientation).
1162 * The slightly worrying thing is the avoidance of full-cross
1163 * squares. Can this cause our unsophisticated construction
1164 * algorithm to paint itself into a corner, by getting into a
1165 * situation where there are some unreached squares and the
1166 * only way to reach any of them is to extend a T-piece into a
1169 * Answer: no it can't, and here's a proof.
1171 * Any contiguous group of such unreachable squares must be
1172 * surrounded on _all_ sides by T-pieces pointing away from the
1173 * group. (If not, then there is a square which can be extended
1174 * into one of the `unreachable' ones, and so it wasn't
1175 * unreachable after all.) In particular, this implies that
1176 * each contiguous group of unreachable squares must be
1177 * rectangular in shape (any deviation from that yields a
1178 * non-T-piece next to an `unreachable' square).
1180 * So we have a rectangle of unreachable squares, with T-pieces
1181 * forming a solid border around the rectangle. The corners of
1182 * that border must be connected (since every tile connects all
1183 * the lines arriving in it), and therefore the border must
1184 * form a closed loop around the rectangle.
1186 * But this can't have happened in the first place, since we
1187 * _know_ we've avoided creating closed loops! Hence, no such
1188 * situation can ever arise, and the naive grid construction
1189 * algorithm will guaranteeably result in a complete grid
1190 * containing no unreached squares, no full crosses _and_ no
1193 possibilities = newtree234(xyd_cmp_nc);
1196 add234(possibilities, new_xyd(cx, cy, R));
1198 add234(possibilities, new_xyd(cx, cy, U));
1200 add234(possibilities, new_xyd(cx, cy, L));
1202 add234(possibilities, new_xyd(cx, cy, D));
1204 while (count234(possibilities) > 0) {
1207 int x1, y1, d1, x2, y2, d2, d;
1210 * Extract a randomly chosen possibility from the list.
1212 i = random_upto(rs, count234(possibilities));
1213 xyd = delpos234(possibilities, i);
1216 d1 = xyd->direction;
1219 OFFSET(x2, y2, x1, y1, d1, params);
1221 #ifdef GENERATION_DIAGNOSTICS
1222 printf("picked (%d,%d,%c) <-> (%d,%d,%c)\n",
1223 x1, y1, "0RU3L567D9abcdef"[d1], x2, y2, "0RU3L567D9abcdef"[d2]);
1227 * Make the connection. (We should be moving to an as yet
1230 index(params, tiles, x1, y1) |= d1;
1231 assert(index(params, tiles, x2, y2) == 0);
1232 index(params, tiles, x2, y2) |= d2;
1235 * If we have created a T-piece, remove its last
1238 if (COUNT(index(params, tiles, x1, y1)) == 3) {
1239 struct xyd xyd1, *xydp;
1243 xyd1.direction = 0x0F ^ index(params, tiles, x1, y1);
1245 xydp = find234(possibilities, &xyd1, NULL);
1248 #ifdef GENERATION_DIAGNOSTICS
1249 printf("T-piece; removing (%d,%d,%c)\n",
1250 xydp->x, xydp->y, "0RU3L567D9abcdef"[xydp->direction]);
1252 del234(possibilities, xydp);
1258 * Remove all other possibilities that were pointing at the
1259 * tile we've just moved into.
1261 for (d = 1; d < 0x10; d <<= 1) {
1263 struct xyd xyd1, *xydp;
1265 OFFSET(x3, y3, x2, y2, d, params);
1270 xyd1.direction = d3;
1272 xydp = find234(possibilities, &xyd1, NULL);
1275 #ifdef GENERATION_DIAGNOSTICS
1276 printf("Loop avoidance; removing (%d,%d,%c)\n",
1277 xydp->x, xydp->y, "0RU3L567D9abcdef"[xydp->direction]);
1279 del234(possibilities, xydp);
1285 * Add new possibilities to the list for moving _out_ of
1286 * the tile we have just moved into.
1288 for (d = 1; d < 0x10; d <<= 1) {
1292 continue; /* we've got this one already */
1294 if (!params->wrapping) {
1295 if (d == U && y2 == 0)
1297 if (d == D && y2 == h-1)
1299 if (d == L && x2 == 0)
1301 if (d == R && x2 == w-1)
1305 OFFSET(x3, y3, x2, y2, d, params);
1307 if (index(params, tiles, x3, y3))
1308 continue; /* this would create a loop */
1310 #ifdef GENERATION_DIAGNOSTICS
1311 printf("New frontier; adding (%d,%d,%c)\n",
1312 x2, y2, "0RU3L567D9abcdef"[d]);
1314 add234(possibilities, new_xyd(x2, y2, d));
1317 /* Having done that, we should have no possibilities remaining. */
1318 assert(count234(possibilities) == 0);
1319 freetree234(possibilities);
1321 if (params->unique) {
1325 * Run the solver to check unique solubility.
1327 while (!net_solver(w, h, tiles, NULL, params->wrapping)) {
1331 * We expect (in most cases) that most of the grid will
1332 * be uniquely specified already, and the remaining
1333 * ambiguous sections will be small and separate. So
1334 * our strategy is to find each individual such
1335 * section, and perform a perturbation on the network
1338 for (y = 0; y < h; y++) for (x = 0; x < w; x++) {
1339 if (x+1 < w && ((tiles[y*w+x] ^ tiles[y*w+x+1]) & LOCKED)) {
1341 if (tiles[y*w+x] & LOCKED)
1342 perturb(w, h, tiles, params->wrapping, rs, x+1, y, L);
1344 perturb(w, h, tiles, params->wrapping, rs, x, y, R);
1346 if (y+1 < h && ((tiles[y*w+x] ^ tiles[(y+1)*w+x]) & LOCKED)) {
1348 if (tiles[y*w+x] & LOCKED)
1349 perturb(w, h, tiles, params->wrapping, rs, x, y+1, U);
1351 perturb(w, h, tiles, params->wrapping, rs, x, y, D);
1356 * Now n counts the number of ambiguous sections we
1357 * have fiddled with. If we haven't managed to decrease
1358 * it from the last time we ran the solver, give up and
1359 * regenerate the entire grid.
1361 if (prevn != -1 && prevn <= n)
1362 goto begin_generation; /* (sorry) */
1368 * The solver will have left a lot of LOCKED bits lying
1369 * around in the tiles array. Remove them.
1371 for (x = 0; x < w*h; x++)
1372 tiles[x] &= ~LOCKED;
1376 * Now compute a list of the possible barrier locations.
1378 barriertree = newtree234(xyd_cmp_nc);
1379 for (y = 0; y < h; y++) {
1380 for (x = 0; x < w; x++) {
1382 if (!(index(params, tiles, x, y) & R) &&
1383 (params->wrapping || x < w-1))
1384 add234(barriertree, new_xyd(x, y, R));
1385 if (!(index(params, tiles, x, y) & D) &&
1386 (params->wrapping || y < h-1))
1387 add234(barriertree, new_xyd(x, y, D));
1392 * Save the unshuffled grid in aux.
1398 solution = snewn(w * h + 1, char);
1399 for (i = 0; i < w * h; i++)
1400 solution[i] = "0123456789abcdef"[tiles[i] & 0xF];
1401 solution[w*h] = '\0';
1407 * Now shuffle the grid.
1409 * In order to avoid accidentally generating an already-solved
1410 * grid, we will reshuffle as necessary to ensure that at least
1411 * one edge has a mismatched connection.
1413 * This can always be done, since validate_params() enforces a
1414 * grid area of at least 2 and our generator never creates
1415 * either type of rotationally invariant tile (cross and
1416 * blank). Hence there must be at least one edge separating
1417 * distinct tiles, and it must be possible to find orientations
1418 * of those tiles such that one tile is trying to connect
1419 * through that edge and the other is not.
1421 * (We could be more subtle, and allow the shuffle to generate
1422 * a grid in which all tiles match up locally and the only
1423 * criterion preventing the grid from being already solved is
1424 * connectedness. However, that would take more effort, and
1425 * it's easier to simply make sure every grid is _obviously_
1431 for (y = 0; y < h; y++) {
1432 for (x = 0; x < w; x++) {
1433 int orig = index(params, tiles, x, y);
1434 int rot = random_upto(rs, 4);
1435 index(params, tiles, x, y) = ROT(orig, rot);
1441 * I can't even be bothered to check for mismatches across
1442 * a wrapping edge, so I'm just going to enforce that there
1443 * must be a mismatch across a non-wrapping edge, which is
1444 * still always possible.
1446 for (y = 0; y < h; y++) for (x = 0; x < w; x++) {
1447 if (x+1 < w && ((ROT(index(params, tiles, x, y), 2) ^
1448 index(params, tiles, x+1, y)) & L))
1450 if (y+1 < h && ((ROT(index(params, tiles, x, y), 2) ^
1451 index(params, tiles, x, y+1)) & U))
1460 * And now choose barrier locations. (We carefully do this
1461 * _after_ shuffling, so that changing the barrier rate in the
1462 * params while keeping the random seed the same will give the
1463 * same shuffled grid and _only_ change the barrier locations.
1464 * Also the way we choose barrier locations, by repeatedly
1465 * choosing one possibility from the list until we have enough,
1466 * is designed to ensure that raising the barrier rate while
1467 * keeping the seed the same will provide a superset of the
1468 * previous barrier set - i.e. if you ask for 10 barriers, and
1469 * then decide that's still too hard and ask for 20, you'll get
1470 * the original 10 plus 10 more, rather than getting 20 new
1471 * ones and the chance of remembering your first 10.)
1473 nbarriers = (int)(params->barrier_probability * count234(barriertree));
1474 assert(nbarriers >= 0 && nbarriers <= count234(barriertree));
1476 while (nbarriers > 0) {
1479 int x1, y1, d1, x2, y2, d2;
1482 * Extract a randomly chosen barrier from the list.
1484 i = random_upto(rs, count234(barriertree));
1485 xyd = delpos234(barriertree, i);
1487 assert(xyd != NULL);
1491 d1 = xyd->direction;
1494 OFFSET(x2, y2, x1, y1, d1, params);
1497 index(params, barriers, x1, y1) |= d1;
1498 index(params, barriers, x2, y2) |= d2;
1504 * Clean up the rest of the barrier list.
1509 while ( (xyd = delpos234(barriertree, 0)) != NULL)
1512 freetree234(barriertree);
1516 * Finally, encode the grid into a string game description.
1518 * My syntax is extremely simple: each square is encoded as a
1519 * hex digit in which bit 0 means a connection on the right,
1520 * bit 1 means up, bit 2 left and bit 3 down. (i.e. the same
1521 * encoding as used internally). Each digit is followed by
1522 * optional barrier indicators: `v' means a vertical barrier to
1523 * the right of it, and `h' means a horizontal barrier below
1526 desc = snewn(w * h * 3 + 1, char);
1528 for (y = 0; y < h; y++) {
1529 for (x = 0; x < w; x++) {
1530 *p++ = "0123456789abcdef"[index(params, tiles, x, y)];
1531 if ((params->wrapping || x < w-1) &&
1532 (index(params, barriers, x, y) & R))
1534 if ((params->wrapping || y < h-1) &&
1535 (index(params, barriers, x, y) & D))
1539 assert(p - desc <= w*h*3);
1548 static char *validate_desc(const game_params *params, const char *desc)
1550 int w = params->width, h = params->height;
1553 for (i = 0; i < w*h; i++) {
1554 if (*desc >= '0' && *desc <= '9')
1556 else if (*desc >= 'a' && *desc <= 'f')
1558 else if (*desc >= 'A' && *desc <= 'F')
1561 return "Game description shorter than expected";
1563 return "Game description contained unexpected character";
1565 while (*desc == 'h' || *desc == 'v')
1569 return "Game description longer than expected";
1574 /* ----------------------------------------------------------------------
1575 * Construct an initial game state, given a description and parameters.
1578 static game_state *new_game(midend *me, const game_params *params,
1584 assert(params->width > 0 && params->height > 0);
1585 assert(params->width > 1 || params->height > 1);
1588 * Create a blank game state.
1590 state = snew(game_state);
1591 w = state->width = params->width;
1592 h = state->height = params->height;
1593 state->wrapping = params->wrapping;
1594 state->last_rotate_dir = state->last_rotate_x = state->last_rotate_y = 0;
1595 state->completed = state->used_solve = FALSE;
1596 state->tiles = snewn(state->width * state->height, unsigned char);
1597 memset(state->tiles, 0, state->width * state->height);
1598 state->barriers = snewn(state->width * state->height, unsigned char);
1599 memset(state->barriers, 0, state->width * state->height);
1602 * Parse the game description into the grid.
1604 for (y = 0; y < h; y++) {
1605 for (x = 0; x < w; x++) {
1606 if (*desc >= '0' && *desc <= '9')
1607 tile(state, x, y) = *desc - '0';
1608 else if (*desc >= 'a' && *desc <= 'f')
1609 tile(state, x, y) = *desc - 'a' + 10;
1610 else if (*desc >= 'A' && *desc <= 'F')
1611 tile(state, x, y) = *desc - 'A' + 10;
1614 while (*desc == 'h' || *desc == 'v') {
1621 OFFSET(x2, y2, x, y, d1, state);
1624 barrier(state, x, y) |= d1;
1625 barrier(state, x2, y2) |= d2;
1633 * Set up border barriers if this is a non-wrapping game.
1635 if (!state->wrapping) {
1636 for (x = 0; x < state->width; x++) {
1637 barrier(state, x, 0) |= U;
1638 barrier(state, x, state->height-1) |= D;
1640 for (y = 0; y < state->height; y++) {
1641 barrier(state, 0, y) |= L;
1642 barrier(state, state->width-1, y) |= R;
1646 * We check whether this is de-facto a non-wrapping game
1647 * despite the parameters, in case we were passed the
1648 * description of a non-wrapping game. This is so that we
1649 * can change some aspects of the UI behaviour.
1651 state->wrapping = FALSE;
1652 for (x = 0; x < state->width; x++)
1653 if (!(barrier(state, x, 0) & U) ||
1654 !(barrier(state, x, state->height-1) & D))
1655 state->wrapping = TRUE;
1656 for (y = 0; y < state->height; y++)
1657 if (!(barrier(state, 0, y) & L) ||
1658 !(barrier(state, state->width-1, y) & R))
1659 state->wrapping = TRUE;
1665 static game_state *dup_game(const game_state *state)
1669 ret = snew(game_state);
1670 ret->width = state->width;
1671 ret->height = state->height;
1672 ret->wrapping = state->wrapping;
1673 ret->completed = state->completed;
1674 ret->used_solve = state->used_solve;
1675 ret->last_rotate_dir = state->last_rotate_dir;
1676 ret->last_rotate_x = state->last_rotate_x;
1677 ret->last_rotate_y = state->last_rotate_y;
1678 ret->tiles = snewn(state->width * state->height, unsigned char);
1679 memcpy(ret->tiles, state->tiles, state->width * state->height);
1680 ret->barriers = snewn(state->width * state->height, unsigned char);
1681 memcpy(ret->barriers, state->barriers, state->width * state->height);
1686 static void free_game(game_state *state)
1688 sfree(state->tiles);
1689 sfree(state->barriers);
1693 static char *solve_game(const game_state *state, const game_state *currstate,
1694 const char *aux, char **error)
1696 unsigned char *tiles;
1698 int retlen, retsize;
1701 tiles = snewn(state->width * state->height, unsigned char);
1705 * Run the internal solver on the provided grid. This might
1706 * not yield a complete solution.
1708 memcpy(tiles, state->tiles, state->width * state->height);
1709 net_solver(state->width, state->height, tiles,
1710 state->barriers, state->wrapping);
1712 for (i = 0; i < state->width * state->height; i++) {
1715 if (c >= '0' && c <= '9')
1717 else if (c >= 'a' && c <= 'f')
1718 tiles[i] = c - 'a' + 10;
1719 else if (c >= 'A' && c <= 'F')
1720 tiles[i] = c - 'A' + 10;
1727 * Now construct a string which can be passed to execute_move()
1728 * to transform the current grid into the solved one.
1731 ret = snewn(retsize, char);
1733 ret[retlen++] = 'S';
1735 for (i = 0; i < state->width * state->height; i++) {
1736 int from = currstate->tiles[i], to = tiles[i];
1737 int ft = from & (R|L|U|D), tt = to & (R|L|U|D);
1738 int x = i % state->width, y = i / state->width;
1740 char buf[80], *p = buf;
1743 continue; /* nothing needs doing at all */
1746 * To transform this tile into the desired tile: first
1747 * unlock the tile if it's locked, then rotate it if
1748 * necessary, then lock it if necessary.
1751 p += sprintf(p, ";L%d,%d", x, y);
1755 else if (tt == C(ft))
1757 else if (tt == F(ft))
1764 p += sprintf(p, ";%c%d,%d", chr, x, y);
1767 p += sprintf(p, ";L%d,%d", x, y);
1770 if (retlen + (p - buf) >= retsize) {
1771 retsize = retlen + (p - buf) + 512;
1772 ret = sresize(ret, retsize, char);
1774 memcpy(ret+retlen, buf, p - buf);
1779 assert(retlen < retsize);
1781 ret = sresize(ret, retlen+1, char);
1788 static int game_can_format_as_text_now(const game_params *params)
1793 static char *game_text_format(const game_state *state)
1798 /* ----------------------------------------------------------------------
1803 * Compute which squares are reachable from the centre square, as a
1804 * quick visual aid to determining how close the game is to
1805 * completion. This is also a simple way to tell if the game _is_
1806 * completed - just call this function and see whether every square
1809 static unsigned char *compute_active(const game_state *state, int cx, int cy)
1811 unsigned char *active;
1815 active = snewn(state->width * state->height, unsigned char);
1816 memset(active, 0, state->width * state->height);
1819 * We only store (x,y) pairs in todo, but it's easier to reuse
1820 * xyd_cmp and just store direction 0 every time.
1822 todo = newtree234(xyd_cmp_nc);
1823 index(state, active, cx, cy) = ACTIVE;
1824 add234(todo, new_xyd(cx, cy, 0));
1826 while ( (xyd = delpos234(todo, 0)) != NULL) {
1827 int x1, y1, d1, x2, y2, d2;
1833 for (d1 = 1; d1 < 0x10; d1 <<= 1) {
1834 OFFSET(x2, y2, x1, y1, d1, state);
1838 * If the next tile in this direction is connected to
1839 * us, and there isn't a barrier in the way, and it
1840 * isn't already marked active, then mark it active and
1841 * add it to the to-examine list.
1843 if ((tile(state, x1, y1) & d1) &&
1844 (tile(state, x2, y2) & d2) &&
1845 !(barrier(state, x1, y1) & d1) &&
1846 !index(state, active, x2, y2)) {
1847 index(state, active, x2, y2) = ACTIVE;
1848 add234(todo, new_xyd(x2, y2, 0));
1852 /* Now we expect the todo list to have shrunk to zero size. */
1853 assert(count234(todo) == 0);
1860 int org_x, org_y; /* origin */
1861 int cx, cy; /* source tile (game coordinates) */
1864 random_state *rs; /* used for jumbling */
1866 int dragtilex, dragtiley, dragstartx, dragstarty, dragged;
1870 static game_ui *new_ui(const game_state *state)
1874 game_ui *ui = snew(game_ui);
1875 ui->org_x = ui->org_y = 0;
1876 ui->cur_x = ui->cx = state->width / 2;
1877 ui->cur_y = ui->cy = state->height / 2;
1878 ui->cur_visible = FALSE;
1879 get_random_seed(&seed, &seedsize);
1880 ui->rs = random_new(seed, seedsize);
1886 static void free_ui(game_ui *ui)
1888 random_free(ui->rs);
1892 static char *encode_ui(const game_ui *ui)
1896 * We preserve the origin and centre-point coordinates over a
1899 sprintf(buf, "O%d,%d;C%d,%d", ui->org_x, ui->org_y, ui->cx, ui->cy);
1903 static void decode_ui(game_ui *ui, const char *encoding)
1905 sscanf(encoding, "O%d,%d;C%d,%d",
1906 &ui->org_x, &ui->org_y, &ui->cx, &ui->cy);
1909 static void game_changed_state(game_ui *ui, const game_state *oldstate,
1910 const game_state *newstate)
1914 struct game_drawstate {
1919 unsigned char *visible;
1922 /* ----------------------------------------------------------------------
1925 static char *interpret_move(const game_state *state, game_ui *ui,
1926 const game_drawstate *ds,
1927 int x, int y, int button)
1930 int tx = -1, ty = -1, dir = 0;
1931 int shift = button & MOD_SHFT, ctrl = button & MOD_CTRL;
1933 NONE, ROTATE_LEFT, ROTATE_180, ROTATE_RIGHT, TOGGLE_LOCK, JUMBLE,
1934 MOVE_ORIGIN, MOVE_SOURCE, MOVE_ORIGIN_AND_SOURCE, MOVE_CURSOR
1937 button &= ~MOD_MASK;
1941 if (button == LEFT_BUTTON ||
1942 button == MIDDLE_BUTTON ||
1944 button == LEFT_DRAG ||
1945 button == LEFT_RELEASE ||
1946 button == RIGHT_DRAG ||
1947 button == RIGHT_RELEASE ||
1949 button == RIGHT_BUTTON) {
1951 if (ui->cur_visible) {
1952 ui->cur_visible = FALSE;
1957 * The button must have been clicked on a valid tile.
1959 x -= WINDOW_OFFSET + TILE_BORDER;
1960 y -= WINDOW_OFFSET + TILE_BORDER;
1965 if (tx >= state->width || ty >= state->height)
1967 /* Transform from physical to game coords */
1968 tx = (tx + ui->org_x) % state->width;
1969 ty = (ty + ui->org_y) % state->height;
1970 if (x % TILE_SIZE >= TILE_SIZE - TILE_BORDER ||
1971 y % TILE_SIZE >= TILE_SIZE - TILE_BORDER)
1976 if (button == MIDDLE_BUTTON
1978 || button == RIGHT_BUTTON /* with a stylus, `right-click' locks */
1982 * Middle button never drags: it only toggles the lock.
1984 action = TOGGLE_LOCK;
1985 } else if (button == LEFT_BUTTON
1986 #ifndef STYLUS_BASED
1987 || button == RIGHT_BUTTON /* (see above) */
1991 * Otherwise, we note down the start point for a drag.
1995 ui->dragstartx = x % TILE_SIZE;
1996 ui->dragstarty = y % TILE_SIZE;
1997 ui->dragged = FALSE;
1998 return nullret; /* no actual action */
1999 } else if (button == LEFT_DRAG
2000 #ifndef STYLUS_BASED
2001 || button == RIGHT_DRAG
2005 * Find the new drag point and see if it necessitates a
2008 int x0,y0, xA,yA, xC,yC, xF,yF;
2010 int d0, dA, dC, dF, dmin;
2015 mx = x - (ui->dragtilex * TILE_SIZE);
2016 my = y - (ui->dragtiley * TILE_SIZE);
2018 x0 = ui->dragstartx;
2019 y0 = ui->dragstarty;
2020 xA = ui->dragstarty;
2021 yA = TILE_SIZE-1 - ui->dragstartx;
2022 xF = TILE_SIZE-1 - ui->dragstartx;
2023 yF = TILE_SIZE-1 - ui->dragstarty;
2024 xC = TILE_SIZE-1 - ui->dragstarty;
2025 yC = ui->dragstartx;
2027 d0 = (mx-x0)*(mx-x0) + (my-y0)*(my-y0);
2028 dA = (mx-xA)*(mx-xA) + (my-yA)*(my-yA);
2029 dF = (mx-xF)*(mx-xF) + (my-yF)*(my-yF);
2030 dC = (mx-xC)*(mx-xC) + (my-yC)*(my-yC);
2032 dmin = min(min(d0,dA),min(dF,dC));
2036 } else if (dF == dmin) {
2037 action = ROTATE_180;
2038 ui->dragstartx = xF;
2039 ui->dragstarty = yF;
2041 } else if (dA == dmin) {
2042 action = ROTATE_LEFT;
2043 ui->dragstartx = xA;
2044 ui->dragstarty = yA;
2046 } else /* dC == dmin */ {
2047 action = ROTATE_RIGHT;
2048 ui->dragstartx = xC;
2049 ui->dragstarty = yC;
2052 } else if (button == LEFT_RELEASE
2053 #ifndef STYLUS_BASED
2054 || button == RIGHT_RELEASE
2059 * There was a click but no perceptible drag:
2060 * revert to single-click behaviour.
2065 if (button == LEFT_RELEASE)
2066 action = ROTATE_LEFT;
2068 action = ROTATE_RIGHT;
2070 return nullret; /* no action */
2073 #else /* USE_DRAGGING */
2075 action = (button == LEFT_BUTTON ? ROTATE_LEFT :
2076 button == RIGHT_BUTTON ? ROTATE_RIGHT : TOGGLE_LOCK);
2078 #endif /* USE_DRAGGING */
2080 } else if (IS_CURSOR_MOVE(button)) {
2082 case CURSOR_UP: dir = U; break;
2083 case CURSOR_DOWN: dir = D; break;
2084 case CURSOR_LEFT: dir = L; break;
2085 case CURSOR_RIGHT: dir = R; break;
2086 default: return nullret;
2088 if (shift && ctrl) action = MOVE_ORIGIN_AND_SOURCE;
2089 else if (shift) action = MOVE_ORIGIN;
2090 else if (ctrl) action = MOVE_SOURCE;
2091 else action = MOVE_CURSOR;
2092 } else if (button == 'a' || button == 's' || button == 'd' ||
2093 button == 'A' || button == 'S' || button == 'D' ||
2094 button == 'f' || button == 'F' ||
2095 IS_CURSOR_SELECT(button)) {
2098 if (button == 'a' || button == 'A' || button == CURSOR_SELECT)
2099 action = ROTATE_LEFT;
2100 else if (button == 's' || button == 'S' || button == CURSOR_SELECT2)
2101 action = TOGGLE_LOCK;
2102 else if (button == 'd' || button == 'D')
2103 action = ROTATE_RIGHT;
2104 else if (button == 'f' || button == 'F')
2105 action = ROTATE_180;
2106 ui->cur_visible = TRUE;
2107 } else if (button == 'j' || button == 'J') {
2108 /* XXX should we have some mouse control for this? */
2114 * The middle button locks or unlocks a tile. (A locked tile
2115 * cannot be turned, and is visually marked as being locked.
2116 * This is a convenience for the player, so that once they are
2117 * sure which way round a tile goes, they can lock it and thus
2118 * avoid forgetting later on that they'd already done that one;
2119 * and the locking also prevents them turning the tile by
2120 * accident. If they change their mind, another middle click
2123 if (action == TOGGLE_LOCK) {
2125 sprintf(buf, "L%d,%d", tx, ty);
2127 } else if (action == ROTATE_LEFT || action == ROTATE_RIGHT ||
2128 action == ROTATE_180) {
2132 * The left and right buttons have no effect if clicked on a
2135 if (tile(state, tx, ty) & LOCKED)
2139 * Otherwise, turn the tile one way or the other. Left button
2140 * turns anticlockwise; right button turns clockwise.
2142 sprintf(buf, "%c%d,%d", (int)(action == ROTATE_LEFT ? 'A' :
2143 action == ROTATE_RIGHT ? 'C' : 'F'), tx, ty);
2145 } else if (action == JUMBLE) {
2147 * Jumble all unlocked tiles to random orientations.
2154 * Maximum string length assumes no int can be converted to
2155 * decimal and take more than 11 digits!
2157 maxlen = state->width * state->height * 25 + 3;
2159 ret = snewn(maxlen, char);
2163 for (jy = 0; jy < state->height; jy++) {
2164 for (jx = 0; jx < state->width; jx++) {
2165 if (!(tile(state, jx, jy) & LOCKED)) {
2166 int rot = random_upto(ui->rs, 4);
2168 p += sprintf(p, ";%c%d,%d", "AFC"[rot-1], jx, jy);
2174 assert(p - ret < maxlen);
2175 ret = sresize(ret, p - ret, char);
2178 } else if (action == MOVE_ORIGIN || action == MOVE_SOURCE ||
2179 action == MOVE_ORIGIN_AND_SOURCE || action == MOVE_CURSOR) {
2181 if (action == MOVE_ORIGIN || action == MOVE_ORIGIN_AND_SOURCE) {
2182 if (state->wrapping) {
2183 OFFSET(ui->org_x, ui->org_y, ui->org_x, ui->org_y, dir, state);
2184 } else return nullret; /* disallowed for non-wrapping grids */
2186 if (action == MOVE_SOURCE || action == MOVE_ORIGIN_AND_SOURCE) {
2187 OFFSET(ui->cx, ui->cy, ui->cx, ui->cy, dir, state);
2189 if (action == MOVE_CURSOR) {
2190 OFFSET(ui->cur_x, ui->cur_y, ui->cur_x, ui->cur_y, dir, state);
2191 ui->cur_visible = TRUE;
2199 static game_state *execute_move(const game_state *from, const char *move)
2202 int tx = -1, ty = -1, n, noanim, orig;
2204 ret = dup_game(from);
2206 if (move[0] == 'J' || move[0] == 'S') {
2208 ret->used_solve = TRUE;
2217 ret->last_rotate_dir = 0; /* suppress animation */
2218 ret->last_rotate_x = ret->last_rotate_y = 0;
2221 if ((move[0] == 'A' || move[0] == 'C' ||
2222 move[0] == 'F' || move[0] == 'L') &&
2223 sscanf(move+1, "%d,%d%n", &tx, &ty, &n) >= 2 &&
2224 tx >= 0 && tx < from->width && ty >= 0 && ty < from->height) {
2225 orig = tile(ret, tx, ty);
2226 if (move[0] == 'A') {
2227 tile(ret, tx, ty) = A(orig);
2229 ret->last_rotate_dir = +1;
2230 } else if (move[0] == 'F') {
2231 tile(ret, tx, ty) = F(orig);
2233 ret->last_rotate_dir = +2; /* + for sake of argument */
2234 } else if (move[0] == 'C') {
2235 tile(ret, tx, ty) = C(orig);
2237 ret->last_rotate_dir = -1;
2239 assert(move[0] == 'L');
2240 tile(ret, tx, ty) ^= LOCKED;
2244 if (*move == ';') move++;
2251 if (tx == -1 || ty == -1) { free_game(ret); return NULL; }
2252 ret->last_rotate_x = tx;
2253 ret->last_rotate_y = ty;
2257 * Check whether the game has been completed.
2259 * For this purpose it doesn't matter where the source square
2260 * is, because we can start from anywhere and correctly
2261 * determine whether the game is completed.
2264 unsigned char *active = compute_active(ret, 0, 0);
2266 int complete = TRUE;
2268 for (x1 = 0; x1 < ret->width; x1++)
2269 for (y1 = 0; y1 < ret->height; y1++)
2270 if ((tile(ret, x1, y1) & 0xF) && !index(ret, active, x1, y1)) {
2272 goto break_label; /* break out of two loops at once */
2279 ret->completed = TRUE;
2286 /* ----------------------------------------------------------------------
2287 * Routines for drawing the game position on the screen.
2290 static game_drawstate *game_new_drawstate(drawing *dr, const game_state *state)
2292 game_drawstate *ds = snew(game_drawstate);
2294 ds->started = FALSE;
2295 ds->width = state->width;
2296 ds->height = state->height;
2297 ds->org_x = ds->org_y = -1;
2298 ds->visible = snewn(state->width * state->height, unsigned char);
2299 ds->tilesize = 0; /* undecided yet */
2300 memset(ds->visible, 0xFF, state->width * state->height);
2305 static void game_free_drawstate(drawing *dr, game_drawstate *ds)
2311 static void game_compute_size(const game_params *params, int tilesize,
2314 *x = WINDOW_OFFSET * 2 + tilesize * params->width + TILE_BORDER;
2315 *y = WINDOW_OFFSET * 2 + tilesize * params->height + TILE_BORDER;
2318 static void game_set_size(drawing *dr, game_drawstate *ds,
2319 const game_params *params, int tilesize)
2321 ds->tilesize = tilesize;
2324 static float *game_colours(frontend *fe, int *ncolours)
2328 ret = snewn(NCOLOURS * 3, float);
2329 *ncolours = NCOLOURS;
2332 * Basic background colour is whatever the front end thinks is
2333 * a sensible default.
2335 frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
2340 ret[COL_WIRE * 3 + 0] = 0.0F;
2341 ret[COL_WIRE * 3 + 1] = 0.0F;
2342 ret[COL_WIRE * 3 + 2] = 0.0F;
2345 * Powered wires and powered endpoints are cyan.
2347 ret[COL_POWERED * 3 + 0] = 0.0F;
2348 ret[COL_POWERED * 3 + 1] = 1.0F;
2349 ret[COL_POWERED * 3 + 2] = 1.0F;
2354 ret[COL_BARRIER * 3 + 0] = 1.0F;
2355 ret[COL_BARRIER * 3 + 1] = 0.0F;
2356 ret[COL_BARRIER * 3 + 2] = 0.0F;
2359 * Unpowered endpoints are blue.
2361 ret[COL_ENDPOINT * 3 + 0] = 0.0F;
2362 ret[COL_ENDPOINT * 3 + 1] = 0.0F;
2363 ret[COL_ENDPOINT * 3 + 2] = 1.0F;
2366 * Tile borders are a darker grey than the background.
2368 ret[COL_BORDER * 3 + 0] = 0.5F * ret[COL_BACKGROUND * 3 + 0];
2369 ret[COL_BORDER * 3 + 1] = 0.5F * ret[COL_BACKGROUND * 3 + 1];
2370 ret[COL_BORDER * 3 + 2] = 0.5F * ret[COL_BACKGROUND * 3 + 2];
2373 * Locked tiles are a grey in between those two.
2375 ret[COL_LOCKED * 3 + 0] = 0.75F * ret[COL_BACKGROUND * 3 + 0];
2376 ret[COL_LOCKED * 3 + 1] = 0.75F * ret[COL_BACKGROUND * 3 + 1];
2377 ret[COL_LOCKED * 3 + 2] = 0.75F * ret[COL_BACKGROUND * 3 + 2];
2382 static void draw_filled_line(drawing *dr, int x1, int y1, int x2, int y2,
2385 draw_line(dr, x1-1, y1, x2-1, y2, COL_WIRE);
2386 draw_line(dr, x1+1, y1, x2+1, y2, COL_WIRE);
2387 draw_line(dr, x1, y1-1, x2, y2-1, COL_WIRE);
2388 draw_line(dr, x1, y1+1, x2, y2+1, COL_WIRE);
2389 draw_line(dr, x1, y1, x2, y2, colour);
2392 static void draw_rect_coords(drawing *dr, int x1, int y1, int x2, int y2,
2395 int mx = (x1 < x2 ? x1 : x2);
2396 int my = (y1 < y2 ? y1 : y2);
2397 int dx = (x2 + x1 - 2*mx + 1);
2398 int dy = (y2 + y1 - 2*my + 1);
2400 draw_rect(dr, mx, my, dx, dy, colour);
2404 * draw_barrier_corner() and draw_barrier() are passed physical coords
2406 static void draw_barrier_corner(drawing *dr, game_drawstate *ds,
2407 int x, int y, int dx, int dy, int phase)
2409 int bx = WINDOW_OFFSET + TILE_SIZE * x;
2410 int by = WINDOW_OFFSET + TILE_SIZE * y;
2413 x1 = (dx > 0 ? TILE_SIZE+TILE_BORDER-1 : 0);
2414 y1 = (dy > 0 ? TILE_SIZE+TILE_BORDER-1 : 0);
2417 draw_rect_coords(dr, bx+x1+dx, by+y1,
2418 bx+x1-TILE_BORDER*dx, by+y1-(TILE_BORDER-1)*dy,
2420 draw_rect_coords(dr, bx+x1, by+y1+dy,
2421 bx+x1-(TILE_BORDER-1)*dx, by+y1-TILE_BORDER*dy,
2424 draw_rect_coords(dr, bx+x1, by+y1,
2425 bx+x1-(TILE_BORDER-1)*dx, by+y1-(TILE_BORDER-1)*dy,
2430 static void draw_barrier(drawing *dr, game_drawstate *ds,
2431 int x, int y, int dir, int phase)
2433 int bx = WINDOW_OFFSET + TILE_SIZE * x;
2434 int by = WINDOW_OFFSET + TILE_SIZE * y;
2437 x1 = (X(dir) > 0 ? TILE_SIZE : X(dir) == 0 ? TILE_BORDER : 0);
2438 y1 = (Y(dir) > 0 ? TILE_SIZE : Y(dir) == 0 ? TILE_BORDER : 0);
2439 w = (X(dir) ? TILE_BORDER : TILE_SIZE - TILE_BORDER);
2440 h = (Y(dir) ? TILE_BORDER : TILE_SIZE - TILE_BORDER);
2443 draw_rect(dr, bx+x1-X(dir), by+y1-Y(dir), w, h, COL_WIRE);
2445 draw_rect(dr, bx+x1, by+y1, w, h, COL_BARRIER);
2450 * draw_tile() is passed physical coordinates
2452 static void draw_tile(drawing *dr, const game_state *state, game_drawstate *ds,
2453 int x, int y, int tile, int src, float angle, int cursor)
2455 int bx = WINDOW_OFFSET + TILE_SIZE * x;
2456 int by = WINDOW_OFFSET + TILE_SIZE * y;
2458 float cx, cy, ex, ey, tx, ty;
2459 int dir, col, phase;
2462 * When we draw a single tile, we must draw everything up to
2463 * and including the borders around the tile. This means that
2464 * if the neighbouring tiles have connections to those borders,
2465 * we must draw those connections on the borders themselves.
2468 clip(dr, bx, by, TILE_SIZE+TILE_BORDER, TILE_SIZE+TILE_BORDER);
2471 * So. First blank the tile out completely: draw a big
2472 * rectangle in border colour, and a smaller rectangle in
2473 * background colour to fill it in.
2475 draw_rect(dr, bx, by, TILE_SIZE+TILE_BORDER, TILE_SIZE+TILE_BORDER,
2477 draw_rect(dr, bx+TILE_BORDER, by+TILE_BORDER,
2478 TILE_SIZE-TILE_BORDER, TILE_SIZE-TILE_BORDER,
2479 tile & LOCKED ? COL_LOCKED : COL_BACKGROUND);
2482 * Draw an inset outline rectangle as a cursor, in whichever of
2483 * COL_LOCKED and COL_BACKGROUND we aren't currently drawing
2487 draw_line(dr, bx+TILE_SIZE/8, by+TILE_SIZE/8,
2488 bx+TILE_SIZE/8, by+TILE_SIZE-TILE_SIZE/8,
2489 tile & LOCKED ? COL_BACKGROUND : COL_LOCKED);
2490 draw_line(dr, bx+TILE_SIZE/8, by+TILE_SIZE/8,
2491 bx+TILE_SIZE-TILE_SIZE/8, by+TILE_SIZE/8,
2492 tile & LOCKED ? COL_BACKGROUND : COL_LOCKED);
2493 draw_line(dr, bx+TILE_SIZE-TILE_SIZE/8, by+TILE_SIZE/8,
2494 bx+TILE_SIZE-TILE_SIZE/8, by+TILE_SIZE-TILE_SIZE/8,
2495 tile & LOCKED ? COL_BACKGROUND : COL_LOCKED);
2496 draw_line(dr, bx+TILE_SIZE/8, by+TILE_SIZE-TILE_SIZE/8,
2497 bx+TILE_SIZE-TILE_SIZE/8, by+TILE_SIZE-TILE_SIZE/8,
2498 tile & LOCKED ? COL_BACKGROUND : COL_LOCKED);
2502 * Set up the rotation matrix.
2504 matrix[0] = (float)cos(angle * PI / 180.0);
2505 matrix[1] = (float)-sin(angle * PI / 180.0);
2506 matrix[2] = (float)sin(angle * PI / 180.0);
2507 matrix[3] = (float)cos(angle * PI / 180.0);
2512 cx = cy = TILE_BORDER + (TILE_SIZE-TILE_BORDER) / 2.0F - 0.5F;
2513 col = (tile & ACTIVE ? COL_POWERED : COL_WIRE);
2514 for (dir = 1; dir < 0x10; dir <<= 1) {
2516 ex = (TILE_SIZE - TILE_BORDER - 1.0F) / 2.0F * X(dir);
2517 ey = (TILE_SIZE - TILE_BORDER - 1.0F) / 2.0F * Y(dir);
2518 MATMUL(tx, ty, matrix, ex, ey);
2519 draw_filled_line(dr, bx+(int)cx, by+(int)cy,
2520 bx+(int)(cx+tx), by+(int)(cy+ty),
2524 for (dir = 1; dir < 0x10; dir <<= 1) {
2526 ex = (TILE_SIZE - TILE_BORDER - 1.0F) / 2.0F * X(dir);
2527 ey = (TILE_SIZE - TILE_BORDER - 1.0F) / 2.0F * Y(dir);
2528 MATMUL(tx, ty, matrix, ex, ey);
2529 draw_line(dr, bx+(int)cx, by+(int)cy,
2530 bx+(int)(cx+tx), by+(int)(cy+ty), col);
2535 * Draw the box in the middle. We do this in blue if the tile
2536 * is an unpowered endpoint, in cyan if the tile is a powered
2537 * endpoint, in black if the tile is the centrepiece, and
2538 * otherwise not at all.
2543 else if (COUNT(tile) == 1) {
2544 col = (tile & ACTIVE ? COL_POWERED : COL_ENDPOINT);
2549 points[0] = +1; points[1] = +1;
2550 points[2] = +1; points[3] = -1;
2551 points[4] = -1; points[5] = -1;
2552 points[6] = -1; points[7] = +1;
2554 for (i = 0; i < 8; i += 2) {
2555 ex = (TILE_SIZE * 0.24F) * points[i];
2556 ey = (TILE_SIZE * 0.24F) * points[i+1];
2557 MATMUL(tx, ty, matrix, ex, ey);
2558 points[i] = bx+(int)(cx+tx);
2559 points[i+1] = by+(int)(cy+ty);
2562 draw_polygon(dr, points, 4, col, COL_WIRE);
2566 * Draw the points on the border if other tiles are connected
2569 for (dir = 1; dir < 0x10; dir <<= 1) {
2570 int dx, dy, px, py, lx, ly, vx, vy, ox, oy;
2578 if (ox < 0 || ox >= state->width || oy < 0 || oy >= state->height)
2581 if (!(tile(state, GX(ox), GY(oy)) & F(dir)))
2584 px = bx + (int)(dx>0 ? TILE_SIZE + TILE_BORDER - 1 : dx<0 ? 0 : cx);
2585 py = by + (int)(dy>0 ? TILE_SIZE + TILE_BORDER - 1 : dy<0 ? 0 : cy);
2586 lx = dx * (TILE_BORDER-1);
2587 ly = dy * (TILE_BORDER-1);
2591 if (angle == 0.0 && (tile & dir)) {
2593 * If we are fully connected to the other tile, we must
2594 * draw right across the tile border. (We can use our
2595 * own ACTIVE state to determine what colour to do this
2596 * in: if we are fully connected to the other tile then
2597 * the two ACTIVE states will be the same.)
2599 draw_rect_coords(dr, px-vx, py-vy, px+lx+vx, py+ly+vy, COL_WIRE);
2600 draw_rect_coords(dr, px, py, px+lx, py+ly,
2601 (tile & ACTIVE) ? COL_POWERED : COL_WIRE);
2604 * The other tile extends into our border, but isn't
2605 * actually connected to us. Just draw a single black
2608 draw_rect_coords(dr, px, py, px, py, COL_WIRE);
2613 * Draw barrier corners, and then barriers.
2615 for (phase = 0; phase < 2; phase++) {
2616 for (dir = 1; dir < 0x10; dir <<= 1) {
2617 int x1, y1, corner = FALSE;
2619 * If at least one barrier terminates at the corner
2620 * between dir and A(dir), draw a barrier corner.
2622 if (barrier(state, GX(x), GY(y)) & (dir | A(dir))) {
2626 * Only count barriers terminating at this corner
2627 * if they're physically next to the corner. (That
2628 * is, if they've wrapped round from the far side
2629 * of the screen, they don't count.)
2633 if (x1 >= 0 && x1 < state->width &&
2634 y1 >= 0 && y1 < state->height &&
2635 (barrier(state, GX(x1), GY(y1)) & A(dir))) {
2640 if (x1 >= 0 && x1 < state->width &&
2641 y1 >= 0 && y1 < state->height &&
2642 (barrier(state, GX(x1), GY(y1)) & dir))
2649 * At least one barrier terminates here. Draw a
2652 draw_barrier_corner(dr, ds, x, y,
2653 X(dir)+X(A(dir)), Y(dir)+Y(A(dir)),
2658 for (dir = 1; dir < 0x10; dir <<= 1)
2659 if (barrier(state, GX(x), GY(y)) & dir)
2660 draw_barrier(dr, ds, x, y, dir, phase);
2665 draw_update(dr, bx, by, TILE_SIZE+TILE_BORDER, TILE_SIZE+TILE_BORDER);
2668 static void game_redraw(drawing *dr, game_drawstate *ds,
2669 const game_state *oldstate, const game_state *state,
2670 int dir, const game_ui *ui,
2673 int x, y, tx, ty, frame, last_rotate_dir, moved_origin = FALSE;
2674 unsigned char *active;
2678 * Clear the screen, and draw the exterior barrier lines, if
2679 * this is our first call or if the origin has changed.
2681 if (!ds->started || ui->org_x != ds->org_x || ui->org_y != ds->org_y) {
2687 WINDOW_OFFSET * 2 + TILE_SIZE * state->width + TILE_BORDER,
2688 WINDOW_OFFSET * 2 + TILE_SIZE * state->height + TILE_BORDER,
2691 ds->org_x = ui->org_x;
2692 ds->org_y = ui->org_y;
2693 moved_origin = TRUE;
2695 draw_update(dr, 0, 0,
2696 WINDOW_OFFSET*2 + TILE_SIZE*state->width + TILE_BORDER,
2697 WINDOW_OFFSET*2 + TILE_SIZE*state->height + TILE_BORDER);
2699 for (phase = 0; phase < 2; phase++) {
2701 for (x = 0; x < ds->width; x++) {
2702 if (x+1 < ds->width) {
2703 if (barrier(state, GX(x), GY(0)) & R)
2704 draw_barrier_corner(dr, ds, x, -1, +1, +1, phase);
2705 if (barrier(state, GX(x), GY(ds->height-1)) & R)
2706 draw_barrier_corner(dr, ds, x, ds->height, +1, -1, phase);
2708 if (barrier(state, GX(x), GY(0)) & U) {
2709 draw_barrier_corner(dr, ds, x, -1, -1, +1, phase);
2710 draw_barrier_corner(dr, ds, x, -1, +1, +1, phase);
2711 draw_barrier(dr, ds, x, -1, D, phase);
2713 if (barrier(state, GX(x), GY(ds->height-1)) & D) {
2714 draw_barrier_corner(dr, ds, x, ds->height, -1, -1, phase);
2715 draw_barrier_corner(dr, ds, x, ds->height, +1, -1, phase);
2716 draw_barrier(dr, ds, x, ds->height, U, phase);
2720 for (y = 0; y < ds->height; y++) {
2721 if (y+1 < ds->height) {
2722 if (barrier(state, GX(0), GY(y)) & D)
2723 draw_barrier_corner(dr, ds, -1, y, +1, +1, phase);
2724 if (barrier(state, GX(ds->width-1), GY(y)) & D)
2725 draw_barrier_corner(dr, ds, ds->width, y, -1, +1, phase);
2727 if (barrier(state, GX(0), GY(y)) & L) {
2728 draw_barrier_corner(dr, ds, -1, y, +1, -1, phase);
2729 draw_barrier_corner(dr, ds, -1, y, +1, +1, phase);
2730 draw_barrier(dr, ds, -1, y, R, phase);
2732 if (barrier(state, GX(ds->width-1), GY(y)) & R) {
2733 draw_barrier_corner(dr, ds, ds->width, y, -1, -1, phase);
2734 draw_barrier_corner(dr, ds, ds->width, y, -1, +1, phase);
2735 draw_barrier(dr, ds, ds->width, y, L, phase);
2742 last_rotate_dir = dir==-1 ? oldstate->last_rotate_dir :
2743 state->last_rotate_dir;
2744 if (oldstate && (t < ROTATE_TIME) && last_rotate_dir) {
2746 * We're animating a single tile rotation. Find the turning
2749 tx = (dir==-1 ? oldstate->last_rotate_x : state->last_rotate_x);
2750 ty = (dir==-1 ? oldstate->last_rotate_y : state->last_rotate_y);
2751 angle = last_rotate_dir * dir * 90.0F * (t / ROTATE_TIME);
2758 * We're animating a completion flash. Find which frame
2761 frame = (int)(ft / FLASH_FRAME);
2765 * Draw any tile which differs from the way it was last drawn.
2767 active = compute_active(state, ui->cx, ui->cy);
2769 for (x = 0; x < ds->width; x++)
2770 for (y = 0; y < ds->height; y++) {
2771 unsigned char c = tile(state, GX(x), GY(y)) |
2772 index(state, active, GX(x), GY(y));
2773 int is_src = GX(x) == ui->cx && GY(y) == ui->cy;
2774 int is_anim = GX(x) == tx && GY(y) == ty;
2775 int is_cursor = ui->cur_visible &&
2776 GX(x) == ui->cur_x && GY(y) == ui->cur_y;
2779 * In a completion flash, we adjust the LOCKED bit
2780 * depending on our distance from the centre point and
2784 int rcx = RX(ui->cx), rcy = RY(ui->cy);
2785 int xdist, ydist, dist;
2786 xdist = (x < rcx ? rcx - x : x - rcx);
2787 ydist = (y < rcy ? rcy - y : y - rcy);
2788 dist = (xdist > ydist ? xdist : ydist);
2790 if (frame >= dist && frame < dist+4) {
2791 int lock = (frame - dist) & 1;
2792 lock = lock ? LOCKED : 0;
2793 c = (c &~ LOCKED) | lock;
2798 index(state, ds->visible, x, y) != c ||
2799 index(state, ds->visible, x, y) == 0xFF ||
2800 is_src || is_anim || is_cursor) {
2801 draw_tile(dr, state, ds, x, y, c,
2802 is_src, (is_anim ? angle : 0.0F), is_cursor);
2803 if (is_src || is_anim || is_cursor)
2804 index(state, ds->visible, x, y) = 0xFF;
2806 index(state, ds->visible, x, y) = c;
2811 * Update the status bar.
2814 char statusbuf[256];
2817 n = state->width * state->height;
2818 for (i = a = n2 = 0; i < n; i++) {
2821 if (state->tiles[i] & 0xF)
2825 sprintf(statusbuf, "%sActive: %d/%d",
2826 (state->used_solve ? "Auto-solved. " :
2827 state->completed ? "COMPLETED! " : ""), a, n2);
2829 status_bar(dr, statusbuf);
2835 static float game_anim_length(const game_state *oldstate,
2836 const game_state *newstate, int dir, game_ui *ui)
2838 int last_rotate_dir;
2841 * Don't animate if last_rotate_dir is zero.
2843 last_rotate_dir = dir==-1 ? oldstate->last_rotate_dir :
2844 newstate->last_rotate_dir;
2845 if (last_rotate_dir)
2851 static float game_flash_length(const game_state *oldstate,
2852 const game_state *newstate, int dir, game_ui *ui)
2855 * If the game has just been completed, we display a completion
2858 if (!oldstate->completed && newstate->completed &&
2859 !oldstate->used_solve && !newstate->used_solve) {
2861 if (size < newstate->width)
2862 size = newstate->width;
2863 if (size < newstate->height)
2864 size = newstate->height;
2865 return FLASH_FRAME * (size+4);
2871 static int game_status(const game_state *state)
2873 return state->completed ? +1 : 0;
2876 static int game_timing_state(const game_state *state, game_ui *ui)
2881 static void game_print_size(const game_params *params, float *x, float *y)
2886 * I'll use 8mm squares by default.
2888 game_compute_size(params, 800, &pw, &ph);
2893 static void draw_diagram(drawing *dr, game_drawstate *ds, int x, int y,
2894 int topleft, int v, int drawlines, int ink)
2896 int tx, ty, cx, cy, r, br, k, thick;
2898 tx = WINDOW_OFFSET + TILE_SIZE * x;
2899 ty = WINDOW_OFFSET + TILE_SIZE * y;
2902 * Find our centre point.
2905 cx = tx + (v & L ? TILE_SIZE / 4 : TILE_SIZE / 6);
2906 cy = ty + (v & U ? TILE_SIZE / 4 : TILE_SIZE / 6);
2908 br = TILE_SIZE / 32;
2910 cx = tx + TILE_SIZE / 2;
2911 cy = ty + TILE_SIZE / 2;
2918 * Draw the square block if we have an endpoint.
2920 if (v == 1 || v == 2 || v == 4 || v == 8)
2921 draw_rect(dr, cx - br, cy - br, br*2, br*2, ink);
2924 * Draw each radial line.
2927 for (k = 1; k < 16; k *= 2)
2929 int x1 = min(cx, cx + (r-thick) * X(k));
2930 int x2 = max(cx, cx + (r-thick) * X(k));
2931 int y1 = min(cy, cy + (r-thick) * Y(k));
2932 int y2 = max(cy, cy + (r-thick) * Y(k));
2933 draw_rect(dr, x1 - thick, y1 - thick,
2934 (x2 - x1) + 2*thick, (y2 - y1) + 2*thick, ink);
2939 static void game_print(drawing *dr, const game_state *state, int tilesize)
2941 int w = state->width, h = state->height;
2942 int ink = print_mono_colour(dr, 0);
2945 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
2946 game_drawstate ads, *ds = &ads;
2947 game_set_size(dr, ds, NULL, tilesize);
2952 print_line_width(dr, TILE_SIZE / (state->wrapping ? 128 : 12));
2953 draw_rect_outline(dr, WINDOW_OFFSET, WINDOW_OFFSET,
2954 TILE_SIZE * w, TILE_SIZE * h, ink);
2959 print_line_width(dr, TILE_SIZE / 128);
2960 for (x = 1; x < w; x++)
2961 draw_line(dr, WINDOW_OFFSET + TILE_SIZE * x, WINDOW_OFFSET,
2962 WINDOW_OFFSET + TILE_SIZE * x, WINDOW_OFFSET + TILE_SIZE * h,
2964 for (y = 1; y < h; y++)
2965 draw_line(dr, WINDOW_OFFSET, WINDOW_OFFSET + TILE_SIZE * y,
2966 WINDOW_OFFSET + TILE_SIZE * w, WINDOW_OFFSET + TILE_SIZE * y,
2972 for (y = 0; y <= h; y++)
2973 for (x = 0; x <= w; x++) {
2974 int b = barrier(state, x % w, y % h);
2975 if (x < w && (b & U))
2976 draw_rect(dr, WINDOW_OFFSET + TILE_SIZE * x - TILE_SIZE/24,
2977 WINDOW_OFFSET + TILE_SIZE * y - TILE_SIZE/24,
2978 TILE_SIZE + TILE_SIZE/24 * 2, TILE_SIZE/24 * 2, ink);
2979 if (y < h && (b & L))
2980 draw_rect(dr, WINDOW_OFFSET + TILE_SIZE * x - TILE_SIZE/24,
2981 WINDOW_OFFSET + TILE_SIZE * y - TILE_SIZE/24,
2982 TILE_SIZE/24 * 2, TILE_SIZE + TILE_SIZE/24 * 2, ink);
2988 for (y = 0; y < h; y++)
2989 for (x = 0; x < w; x++) {
2990 int vx, v = tile(state, x, y);
2991 int locked = v & LOCKED;
2996 * Rotate into a standard orientation for the top left
3000 while (vx != 0 && vx != 15 && vx != 1 && vx != 9 && vx != 13 &&
3005 * Draw the top left corner diagram.
3007 draw_diagram(dr, ds, x, y, TRUE, vx, TRUE, ink);
3010 * Draw the real solution diagram, if we're doing so.
3012 draw_diagram(dr, ds, x, y, FALSE, v, locked, ink);
3020 const struct game thegame = {
3021 "Net", "games.net", "net",
3028 TRUE, game_configure, custom_params,
3036 FALSE, game_can_format_as_text_now, game_text_format,
3044 PREFERRED_TILE_SIZE, game_compute_size, game_set_size,
3047 game_free_drawstate,
3052 TRUE, FALSE, game_print_size, game_print,
3053 TRUE, /* wants_statusbar */
3054 FALSE, game_timing_state,