2 * Implementation of 'Train Tracks', a puzzle from the Times on Saturday.
4 * "Lay tracks to enable the train to travel from village A to village B.
5 * The numbers indicate how many sections of rail go in each row and
6 * column. There are only straight rails and curved rails. The track
7 * cannot cross itself."
10 * #9 8x8:d9s5c6zgAa,1,4,1,4,4,3,S3,5,2,2,4,S5,3,3,5,1
11 * #112 8x8:w6x5mAa,1,3,1,4,6,4,S4,3,3,4,5,2,4,2,S5,1
12 * #113 8x8:gCx5xAf,1,S4,2,5,4,6,2,3,4,2,5,2,S4,4,5,1
13 * #114 8x8:p5fAzkAb,1,6,3,3,3,S6,2,3,5,4,S3,3,5,1,5,1
14 * #115 8x8:zi9d5tAb,1,3,4,5,3,S4,2,4,2,6,2,3,6,S3,3,1
26 /* --- Game parameters --- */
29 * Difficulty levels. I do some macro ickery here to ensure that my
30 * enum and the various forms of my name list always match up.
36 #define ENUM(upper,title,lower) DIFF_ ## upper,
37 #define TITLE(upper,title,lower) #title,
38 #define ENCODE(upper,title,lower) #lower
39 #define CONFIG(upper,title,lower) ":" #title
40 enum { DIFFLIST(ENUM) DIFFCOUNT };
41 static char const *const tracks_diffnames[] = { DIFFLIST(TITLE) };
42 static char const tracks_diffchars[] = DIFFLIST(ENCODE);
43 #define DIFFCONFIG DIFFLIST(CONFIG)
46 int w, h, diff, single_ones;
49 static game_params *default_params(void)
51 game_params *ret = snew(game_params);
54 ret->diff = DIFF_TRICKY;
55 ret->single_ones = TRUE;
60 static const struct game_params tracks_presets[] = {
62 {8, 8, DIFF_TRICKY, 1},
63 {10, 8, DIFF_EASY, 1},
64 {10, 8, DIFF_TRICKY, 1 },
65 {10, 10, DIFF_EASY, 1},
66 {10, 10, DIFF_TRICKY, 1},
67 {15, 10, DIFF_EASY, 1},
68 {15, 10, DIFF_TRICKY, 1},
69 {15, 15, DIFF_EASY, 1},
70 {15, 15, DIFF_TRICKY, 1},
73 static int game_fetch_preset(int i, char **name, game_params **params)
78 if (i < 0 || i >= lenof(tracks_presets))
81 ret = snew(game_params);
82 *ret = tracks_presets[i];
84 sprintf(str, "%dx%d %s", ret->w, ret->h, tracks_diffnames[ret->diff]);
91 static void free_params(game_params *params)
96 static game_params *dup_params(const game_params *params)
98 game_params *ret = snew(game_params);
99 *ret = *params; /* structure copy */
103 static void decode_params(game_params *params, char const *string)
105 params->w = params->h = atoi(string);
106 while (*string && isdigit((unsigned char)*string)) string++;
107 if (*string == 'x') {
109 params->h = atoi(string);
110 while (*string && isdigit((unsigned char)*string)) string++;
112 if (*string == 'd') {
115 params->diff = DIFF_TRICKY;
116 for (i = 0; i < DIFFCOUNT; i++)
117 if (*string == tracks_diffchars[i])
119 if (*string) string++;
121 params->single_ones = TRUE;
122 if (*string == 'o') {
123 params->single_ones = FALSE;
129 static char *encode_params(const game_params *params, int full)
133 sprintf(buf, "%dx%d", params->w, params->h);
135 sprintf(buf + strlen(buf), "d%c%s",
136 tracks_diffchars[params->diff],
137 params->single_ones ? "" : "o");
141 static config_item *game_configure(const game_params *params)
146 ret = snewn(5, config_item);
148 ret[0].name = "Width";
149 ret[0].type = C_STRING;
150 sprintf(buf, "%d", params->w);
151 ret[0].sval = dupstr(buf);
154 ret[1].name = "Height";
155 ret[1].type = C_STRING;
156 sprintf(buf, "%d", params->h);
157 ret[1].sval = dupstr(buf);
160 ret[2].name = "Difficulty";
161 ret[2].type = C_CHOICES;
162 ret[2].sval = DIFFCONFIG;
163 ret[2].ival = params->diff;
165 ret[3].name = "Disallow consecutive 1 clues";
166 ret[3].type = C_BOOLEAN;
167 ret[3].ival = params->single_ones;
177 static game_params *custom_params(const config_item *cfg)
179 game_params *ret = snew(game_params);
181 ret->w = atoi(cfg[0].sval);
182 ret->h = atoi(cfg[1].sval);
183 ret->diff = cfg[2].ival;
184 ret->single_ones = cfg[3].ival;
189 static char *validate_params(const game_params *params, int full)
192 * Generating anything under 4x4 runs into trouble of one kind
195 if (params->w < 4 || params->h < 4)
196 return "Width and height must both be at least four";
200 /* --- Game state --- */
202 /* flag usage copied from pearl */
209 #define MOVECHAR(m) ((m==R)?'R':(m==U)?'U':(m==L)?'L':(m==D)?'D':'?')
211 #define DX(d) ( ((d)==R) - ((d)==L) )
212 #define DY(d) ( ((d)==D) - ((d)==U) )
214 #define F(d) (((d << 2) | (d >> 2)) & 0xF)
215 #define C(d) (((d << 3) | (d >> 1)) & 0xF)
216 #define A(d) (((d << 1) | (d >> 3)) & 0xF)
234 int nbits[] = { 0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4 };
236 /* square grid flags */
237 #define S_TRACK 1 /* a track passes through this square (--> 2 edges) */
238 #define S_NOTRACK 2 /* no track passes through this square */
243 #define S_TRACK_SHIFT 16 /* U/D/L/R flags for edge track indicators */
244 #define S_NOTRACK_SHIFT 20 /* U/D/L/R flags for edge no-track indicators */
246 /* edge grid flags */
247 #define E_TRACK 1 /* a track passes through this edge */
248 #define E_NOTRACK 2 /* no track passes through this edge */
252 int *numbers; /* sz w+h */
253 int row_s, col_s; /* stations: TODO think about multiple lines
254 (for bigger grids)? */
257 #define INGRID(state, gx, gy) ((gx) >= 0 && (gx) < (state)->p.w && \
258 (gy) >= 0 && (gy) < (state)->p.h)
262 unsigned int *sflags; /* size w*h */
263 struct numbers *numbers;
264 int *num_errors; /* size w+h */
265 int completed, used_solve, impossible;
268 /* Return the four directions in which a particular edge flag is set, around a square. */
269 int S_E_DIRS(const game_state *state, int sx, int sy, unsigned int eflag) {
270 return (state->sflags[sy*state->p.w+sx] >>
271 ((eflag == E_TRACK) ? S_TRACK_SHIFT : S_NOTRACK_SHIFT)) & ALLDIR;
274 /* Count the number of a particular edge flag around a grid square. */
275 int S_E_COUNT(const game_state *state, int sx, int sy, unsigned int eflag) {
276 return nbits[S_E_DIRS(state, sx, sy, eflag)];
279 /* Return the two flags (E_TRACK and/or E_NOTRACK) set on a specific
280 * edge of a square. */
281 unsigned S_E_FLAGS(const game_state *state, int sx, int sy, int d) {
282 unsigned f = state->sflags[sy*state->p.w+sx];
283 int t = (f & (d << S_TRACK_SHIFT)), nt = (f & (d << S_NOTRACK_SHIFT));
284 return (t ? E_TRACK : 0) | (nt ? E_NOTRACK : 0);
287 int S_E_ADJ(const game_state *state, int sx, int sy, int d, int *ax, int *ay, unsigned int *ad) {
288 if (d == L && sx > 0) { *ax = sx-1; *ay = sy; *ad = R; return 1; }
289 if (d == R && sx < state->p.w-1) { *ax = sx+1; *ay = sy; *ad = L; return 1; }
290 if (d == U && sy > 0) { *ax = sx; *ay = sy-1; *ad = D; return 1; }
291 if (d == D && sy < state->p.h-1) { *ax = sx; *ay = sy+1; *ad = U; return 1; }
296 /* Sets flag (E_TRACK or E_NOTRACK) on a given edge of a square. */
297 void S_E_SET(game_state *state, int sx, int sy, int d, unsigned int eflag) {
298 unsigned shift = (eflag == E_TRACK) ? S_TRACK_SHIFT : S_NOTRACK_SHIFT, ad;
301 state->sflags[sy*state->p.w+sx] |= (d << shift);
303 if (S_E_ADJ(state, sx, sy, d, &ax, &ay, &ad)) {
304 state->sflags[ay*state->p.w+ax] |= (ad << shift);
308 /* Clears flag (E_TRACK or E_NOTRACK) on a given edge of a square. */
309 void S_E_CLEAR(game_state *state, int sx, int sy, int d, unsigned int eflag) {
310 unsigned shift = (eflag == E_TRACK) ? S_TRACK_SHIFT : S_NOTRACK_SHIFT, ad;
313 state->sflags[sy*state->p.w+sx] &= ~(d << shift);
315 if (S_E_ADJ(state, sx, sy, d, &ax, &ay, &ad)) {
316 state->sflags[ay*state->p.w+ax] &= ~(ad << shift);
320 static void clear_game(game_state *state)
322 int w = state->p.w, h = state->p.h;
324 memset(state->sflags, 0, w*h * sizeof(unsigned int));
326 memset(state->numbers->numbers, 0, (w+h) * sizeof(int));
327 state->numbers->col_s = state->numbers->row_s = -1;
329 memset(state->num_errors, 0, (w+h) * sizeof(int));
331 state->completed = state->used_solve = state->impossible = FALSE;
334 static game_state *blank_game(const game_params *params)
336 game_state *state = snew(game_state);
337 int w = params->w, h = params->h;
341 state->sflags = snewn(w*h, unsigned int);
343 state->numbers = snew(struct numbers);
344 state->numbers->refcount = 1;
345 state->numbers->numbers = snewn(w+h, int);
347 state->num_errors = snewn(w+h, int);
354 static void copy_game_flags(const game_state *src, game_state *dest)
356 int w = src->p.w, h = src->p.h;
358 memcpy(dest->sflags, src->sflags, w*h*sizeof(unsigned int));
361 static game_state *dup_game(const game_state *state)
363 int w = state->p.w, h = state->p.h;
364 game_state *ret = snew(game_state);
366 ret->p = state->p; /* structure copy */
368 ret->sflags = snewn(w*h, unsigned int);
369 copy_game_flags(state, ret);
371 ret->numbers = state->numbers;
372 state->numbers->refcount++;
373 ret->num_errors = snewn(w+h, int);
374 memcpy(ret->num_errors, state->num_errors, (w+h)*sizeof(int));
376 ret->completed = state->completed;
377 ret->used_solve = state->used_solve;
378 ret->impossible = state->impossible;
383 static void free_game(game_state *state)
385 if (--state->numbers->refcount <= 0) {
386 sfree(state->numbers->numbers);
387 sfree(state->numbers);
389 sfree(state->num_errors);
390 sfree(state->sflags);
395 const unsigned int dirs_const[] = { U, D, L, R };
397 static unsigned int find_direction(game_state *state, random_state *rs,
400 int i, nx, ny, w=state->p.w, h=state->p.h;
401 unsigned int dirs[NDIRS];
403 memcpy(dirs, dirs_const, sizeof(dirs));
404 shuffle(dirs, NDIRS, sizeof(*dirs), rs);
405 for (i = 0; i < NDIRS; i++) {
406 nx = x + DX(dirs[i]);
407 ny = y + DY(dirs[i]);
408 if (nx >= 0 && nx < w && ny == h) {
409 /* off the bottom of the board: we've finished the path. */
411 } else if (!INGRID(state, nx, ny)) {
412 /* off the board: can't move here */
414 } else if (S_E_COUNT(state, nx, ny, E_TRACK) > 0) {
415 /* already tracks here: can't move */
420 return 0; /* no possible directions left. */
423 static int check_completion(game_state *state, int mark);
425 static void lay_path(game_state *state, random_state *rs)
427 int px, py, w=state->p.w, h=state->p.h;
433 /* pick a random entry point, lay its left edge */
434 state->numbers->row_s = py = random_upto(rs, h);
436 S_E_SET(state, px, py, L, E_TRACK);
438 while (INGRID(state, px, py)) {
439 d = find_direction(state, rs, px, py);
441 goto start; /* nowhere else to go, restart */
443 S_E_SET(state, px, py, d, E_TRACK);
447 /* double-check we got to the right place */
448 assert(px >= 0 && px < w && py == h);
450 state->numbers->col_s = px;
453 static int tracks_solve(game_state *state, int diff);
454 static void debug_state(game_state *state, const char *what);
456 /* Clue-setting algorithm:
458 - first lay clues randomly until it's soluble
459 - then remove clues randomly if removing them doesn't affect solubility
461 - We start with two clues, one at each path entrance.
464 - start with an array of all square i positions
465 - if the grid is already soluble by a level easier than we've requested,
466 go back and make a new grid
467 - if the grid is already soluble by our requested difficulty level, skip
469 - count the number of flags the solver managed to place, remember this.
472 - shuffle the i positions
473 - for each possible clue position:
474 - copy the solved board, strip it
475 - take the next position, add a clue there on the copy
476 - try and solve the copy
477 - if it's soluble by a level easier than we've requested, continue (on
478 to next clue position: putting a clue here makes it too easy)
479 - if it's soluble by our difficulty level, we're done:
480 - put the clue flag into the solved board
482 - if the solver didn't manage to place any more flags, continue (on to next
483 clue position: putting a clue here didn't help he solver)
484 - otherwise put the clue flag in the original board, and go on to the next
486 - if we get here and we've not solved it yet, we never will (did we really
487 fill _all_ the clues in?!). Go back and make a new grid.
490 - shuffle the i positions
491 - for each possible clue position:
492 - if the solved grid doesn't have a clue here, skip
493 - copy the solved board, remove this clue, strip it
494 - try and solve the copy
495 - assert that it is not soluble by a level easier than we've requested
496 - (because this should never happen)
497 - if this is (still) soluble by our difficulty level:
498 - remove this clue from the solved board, it's redundant (with the other
504 static game_state *copy_and_strip(const game_state *state, game_state *ret, int flipcluei)
506 int i, j, w = state->p.w, h = state->p.h;
508 copy_game_flags(state, ret);
510 /* Add/remove a clue before stripping, if required */
513 ret->sflags[flipcluei] ^= S_CLUE;
515 /* All squares that are not clue squares have square track info erased, and some edge flags.. */
517 for (i = 0; i < w*h; i++) {
518 if (!(ret->sflags[i] & S_CLUE)) {
519 ret->sflags[i] &= ~(S_TRACK|S_NOTRACK|S_ERROR|S_MARK);
520 for (j = 0; j < 4; j++) {
522 int xx = i%w + DX(f), yy = i/w + DY(f);
523 if (!INGRID(state, xx, yy) || !(ret->sflags[yy*w+xx] & S_CLUE)) {
524 /* only erase an edge flag if neither side of the edge is S_CLUE. */
525 S_E_CLEAR(ret, i%w, i/w, f, E_TRACK);
526 S_E_CLEAR(ret, i%w, i/w, f, E_NOTRACK);
534 static int solve_progress(const game_state *state) {
535 int i, w = state->p.w, h = state->p.h, progress = 0;
537 /* Work out how many flags the solver managed to set (either TRACK
538 or NOTRACK) and return this as a progress measure, to check whether
539 a partially-solved board gets any further than a previous partially-
542 for (i = 0; i < w*h; i++) {
543 if (state->sflags[i] & S_TRACK) progress++;
544 if (state->sflags[i] & S_NOTRACK) progress++;
545 progress += S_E_COUNT(state, i%w, i/w, E_TRACK);
546 progress += S_E_COUNT(state, i%w, i/w, E_NOTRACK);
551 static int check_phantom_moves(const game_state *state) {
554 /* Check that this state won't show 'phantom moves' at the start of the
555 * game: squares which have multiple edge flags set but no clue flag
556 * cause a piece of track to appear that isn't on a clue square. */
558 for (x = 0; x < state->p.w; x++) {
559 for (y = 0; y < state->p.h; y++) {
561 if (state->sflags[i] & S_CLUE)
563 if (S_E_COUNT(state, x, y, E_TRACK) > 1)
564 return 1; /* found one! */
570 static int add_clues(game_state *state, random_state *rs, int diff)
572 int i, j, pi, w = state->p.w, h = state->p.h, progress, ret = 0, sr;
573 int *positions = snewn(w*h, int), npositions = 0;
574 int *nedges_previous_solve = snewn(w*h, int);
575 game_state *scratch = dup_game(state);
577 debug_state(state, "gen: Initial board");
579 debug(("gen: Adding clues..."));
581 /* set up the shuffly-position grid for later, used for adding clues:
582 * we only bother adding clues where any edges are set. */
583 for (i = 0; i < w*h; i++) {
584 if (S_E_DIRS(state, i%w, i/w, E_TRACK) != 0) {
585 positions[npositions++] = i;
587 nedges_previous_solve[i] = 0;
590 /* First, check whether the puzzle is already either too easy, or just right */
591 scratch = copy_and_strip(state, scratch, -1);
593 sr = tracks_solve(scratch, diff-1);
595 assert(!"Generator should not have created impossible puzzle");
597 ret = -1; /* already too easy, even without adding clues. */
598 debug(("gen: ...already too easy, need new board."));
602 sr = tracks_solve(scratch, diff);
604 assert(!"Generator should not have created impossible puzzle");
606 ret = 1; /* already soluble without any extra clues. */
607 debug(("gen: ...soluble without clues, nothing to do."));
610 debug_state(scratch, "gen: Initial part-solved state: ");
611 progress = solve_progress(scratch);
612 debug(("gen: Initial solve progress is %d", progress));
614 /* First, lay clues until we're soluble. */
615 shuffle(positions, npositions, sizeof(int), rs);
616 for (pi = 0; pi < npositions; pi++) {
617 i = positions[pi]; /* pick a random position */
618 if (state->sflags[i] & S_CLUE)
619 continue; /* already a clue here (entrance location?) */
620 if (nedges_previous_solve[i] == 2)
621 continue; /* no point putting a clue here, we could solve both edges
622 with the previous set of clues */
624 /* set a clue in that position (on a copy of the board) and test solubility */
625 scratch = copy_and_strip(state, scratch, i);
627 if (check_phantom_moves(scratch))
628 continue; /* adding a clue here would add phantom track */
631 if (tracks_solve(scratch, diff-1) > 0) {
632 continue; /* adding a clue here makes it too easy */
635 if (tracks_solve(scratch, diff) > 0) {
636 /* we're now soluble (and we weren't before): add this clue, and then
637 start stripping clues */
638 debug(("gen: ...adding clue at (%d,%d), now soluble", i%w, i/w));
639 state->sflags[i] |= S_CLUE;
642 if (solve_progress(scratch) > progress) {
643 /* We've made more progress solving: add this clue, then. */
644 progress = solve_progress(scratch);
645 debug(("gen: ... adding clue at (%d,%d), new progress %d", i%w, i/w, progress));
646 state->sflags[i] |= S_CLUE;
648 for (j = 0; j < w*h; j++)
649 nedges_previous_solve[j] = S_E_COUNT(scratch, j%w, j/w, E_TRACK);
652 /* If we got here we didn't ever manage to make the puzzle soluble
653 (without making it too easily soluble, that is): give up. */
655 debug(("gen: Unable to make soluble with clues, need new board."));
660 debug(("gen: Stripping clues."));
662 /* Now, strip redundant clues (i.e. those without which the puzzle is still
664 shuffle(positions, npositions, sizeof(int), rs);
665 for (pi = 0; pi < npositions; pi++) {
666 i = positions[pi]; /* pick a random position */
667 if (!(state->sflags[i] & S_CLUE))
668 continue; /* no clue here to strip */
669 if ((i%w == 0 && i/w == state->numbers->row_s) ||
670 (i/w == (h-1) && i%w == state->numbers->col_s))
671 continue; /* don't strip clues at entrance/exit */
673 scratch = copy_and_strip(state, scratch, i);
674 if (check_phantom_moves(scratch))
675 continue; /* removing a clue here would add phantom track */
677 if (tracks_solve(scratch, diff) > 0) {
678 debug(("gen: ... removing clue at (%d,%d), still soluble without it", i%w, i/w));
679 state->sflags[i] &= ~S_CLUE; /* still soluble without this clue. */
682 debug(("gen: Finished stripping clues."));
691 static char *new_game_desc(const game_params *params, random_state *rs,
692 char **aux, int interactive)
694 int i, j, w = params->w, h = params->h, x, y, ret;
697 game_params adjusted_params;
700 * 4x4 Tricky cannot be generated, so fall back to Easy.
702 if (w == 4 && h == 4 && params->diff > DIFF_EASY) {
703 adjusted_params = *params; /* structure copy */
704 adjusted_params.diff = DIFF_EASY;
705 params = &adjusted_params;
708 state = blank_game(params);
710 /* --- lay the random path */
714 for (x = 0; x < w; x++) {
715 for (y = 0; y < h; y++) {
716 if (S_E_COUNT(state, x, y, E_TRACK) > 0) {
717 state->sflags[y*w + x] |= S_TRACK;
719 if ((x == 0 && y == state->numbers->row_s) ||
720 (y == (h-1) && x == state->numbers->col_s)) {
721 state->sflags[y*w + x] |= S_CLUE;
726 /* --- Update the clue numbers based on the tracks we have generated. */
727 for (x = 0; x < w; x++) {
728 for (y = 0; y < h; y++) {
729 if (state->sflags[y*w + x] & S_TRACK) {
730 state->numbers->numbers[x]++;
731 state->numbers->numbers[y+w]++;
735 for (i = 0; i < w+h; i++) {
736 if (state->numbers->numbers[i] == 0)
737 goto newpath; /* too boring */
740 if (params->single_ones) {
741 int last_was_one = 1, is_one; /* (disallow 1 clue at entry point) */
742 for (i = 0; i < w+h; i++) {
743 is_one = (state->numbers->numbers[i] == 1);
744 if (is_one && last_was_one)
745 goto newpath; /* disallow consecutive 1 clues. */
746 last_was_one = is_one;
748 if (state->numbers->numbers[w+h-1] == 1)
749 goto newpath; /* (disallow 1 clue at exit point) */
752 /* --- Add clues to make a soluble puzzle */
753 ret = add_clues(state, rs, params->diff);
754 if (ret != 1) goto newpath; /* couldn't make it soluble, or too easy */
756 /* --- Generate the game desc based on the generated grid. */
757 desc = snewn(w*h*3 + (w+h)*5, char);
758 for (i = j = 0; i < w*h; i++) {
759 if (!(state->sflags[i] & S_CLUE) && j > 0 &&
760 desc[j-1] >= 'a' && desc[j-1] < 'z')
762 else if (!(state->sflags[i] & S_CLUE))
765 unsigned int f = S_E_DIRS(state, i%w, i/w, E_TRACK);
766 desc[j++] = (f < 10) ? ('0' + f) : ('A' + (f-10));
771 for (x = 0; x < w; x++) {
772 p += sprintf(p, ",%s%d", x == state->numbers->col_s ? "S" : "",
773 state->numbers->numbers[x]);
775 for (y = 0; y < h; y++) {
776 p += sprintf(p, ",%s%d", y == state->numbers->row_s ? "S" : "",
777 state->numbers->numbers[y+w]);
781 ret = tracks_solve(state, DIFFCOUNT);
785 debug(("new_game_desc: %s", desc));
789 static char *validate_desc(const game_params *params, const char *desc)
791 int i = 0, w = params->w, h = params->h, in = 0, out = 0;
795 if (*desc >= '0' && *desc <= '9')
797 else if (*desc >= 'A' && *desc <= 'F')
798 f = (*desc - 'A' + 10);
799 else if (*desc >= 'a' && *desc <= 'z')
802 return "Game description contained unexpected characters";
806 return "Clue did not provide 2 direction flags";
812 for (i = 0; i < w+h; i++) {
814 return "Not enough numbers given after grid specification";
815 else if (*desc != ',')
816 return "Invalid character in number list";
825 while (*desc && isdigit((unsigned char)*desc)) desc++;
827 if (in != 1 || out != 1)
828 return "Puzzle must have one entrance and one exit";
830 return "Unexpected additional character at end of game description";
834 static game_state *new_game(midend *me, const game_params *params, const char *desc)
836 game_state *state = blank_game(params);
837 int w = params->w, h = params->h, i = 0;
841 if (*desc >= '0' && *desc <= '9')
843 else if (*desc >= 'A' && *desc <= 'F')
844 f = (*desc - 'A' + 10);
845 else if (*desc >= 'a' && *desc <= 'z')
849 int x = i % w, y = i / w;
851 assert(nbits[f] == 2);
853 state->sflags[i] |= (S_TRACK | S_CLUE);
854 if (f & U) S_E_SET(state, x, y, U, E_TRACK);
855 if (f & D) S_E_SET(state, x, y, D, E_TRACK);
856 if (f & L) S_E_SET(state, x, y, L, E_TRACK);
857 if (f & R) S_E_SET(state, x, y, R, E_TRACK);
863 for (i = 0; i < w+h; i++) {
864 assert(*desc == ',');
869 state->numbers->col_s = i;
871 state->numbers->row_s = i-w;
874 state->numbers->numbers[i] = atoi(desc);
875 while (*desc && isdigit((unsigned char)*desc)) desc++;
883 static int solve_set_sflag(game_state *state, int x, int y,
884 unsigned int f, const char *why)
886 int w = state->p.w, i = y*w + x;
888 if (state->sflags[i] & f)
890 debug(("solve: square (%d,%d) -> %s: %s",
891 x, y, (f == S_TRACK ? "TRACK" : "NOTRACK"), why));
892 if (state->sflags[i] & (f == S_TRACK ? S_NOTRACK : S_TRACK)) {
893 debug(("solve: opposite flag already set there, marking IMPOSSIBLE"));
894 state->impossible = TRUE;
896 state->sflags[i] |= f;
900 static int solve_set_eflag(game_state *state, int x, int y, int d,
901 unsigned int f, const char *why)
903 int sf = S_E_FLAGS(state, x, y, d);
907 debug(("solve: edge (%d,%d)/%c -> %s: %s", x, y,
908 (d == U) ? 'U' : (d == D) ? 'D' : (d == L) ? 'L' : 'R',
909 (f == S_TRACK ? "TRACK" : "NOTRACK"), why));
910 if (sf & (f == E_TRACK ? E_NOTRACK : E_TRACK)) {
911 debug(("solve: opposite flag already set there, marking IMPOSSIBLE"));
912 state->impossible = TRUE;
914 S_E_SET(state, x, y, d, f);
918 static int solve_update_flags(game_state *state)
920 int x, y, i, w = state->p.w, h = state->p.h, did = 0;
922 for (x = 0; x < w; x++) {
923 for (y = 0; y < h; y++) {
924 /* If a square is NOTRACK, all four edges must be. */
925 if (state->sflags[y*w + x] & S_NOTRACK) {
926 for (i = 0; i < 4; i++) {
927 unsigned int d = 1<<i;
928 did += solve_set_eflag(state, x, y, d, E_NOTRACK, "edges around NOTRACK");
932 /* If 3 or more edges around a square are NOTRACK, the square is. */
933 if (S_E_COUNT(state, x, y, E_NOTRACK) >= 3) {
934 did += solve_set_sflag(state, x, y, S_NOTRACK, "square has >2 NOTRACK edges");
937 /* If any edge around a square is TRACK, the square is. */
938 if (S_E_COUNT(state, x, y, E_TRACK) > 0) {
939 did += solve_set_sflag(state, x, y, S_TRACK, "square has TRACK edge");
942 /* If a square is TRACK and 2 edges are NOTRACK,
943 the other two edges must be TRACK. */
944 if ((state->sflags[y*w + x] & S_TRACK) &&
945 (S_E_COUNT(state, x, y, E_NOTRACK) == 2) &&
946 (S_E_COUNT(state, x, y, E_TRACK) < 2)) {
947 for (i = 0; i < 4; i++) {
948 unsigned int d = 1<<i;
949 if (!(S_E_FLAGS(state, x, y, d) & (E_TRACK|E_NOTRACK))) {
950 did += solve_set_eflag(state, x, y, d, E_TRACK,
951 "TRACK square/2 NOTRACK edges");
956 /* If a square is TRACK and 2 edges are TRACK, the other two
958 if ((state->sflags[y*w + x] & S_TRACK) &&
959 (S_E_COUNT(state, x, y, E_TRACK) == 2) &&
960 (S_E_COUNT(state, x, y, E_NOTRACK) < 2)) {
961 for (i = 0; i < 4; i++) {
962 unsigned int d = 1<<i;
963 if (!(S_E_FLAGS(state, x, y, d) & (E_TRACK|E_NOTRACK))) {
964 did += solve_set_eflag(state, x, y, d, E_NOTRACK,
965 "TRACK square/2 TRACK edges");
974 static int solve_count_col(game_state *state, int col, unsigned int f)
976 int i, n, c = 0, h = state->p.h, w = state->p.w;
977 for (n = 0, i = col; n < h; n++, i += w) {
978 if (state->sflags[i] & f) c++;
983 static int solve_count_row(game_state *state, int row, unsigned int f)
985 int i, n, c = 0, w = state->p.w;
986 for (n = 0, i = w*row; n < state->p.w; n++, i++) {
987 if (state->sflags[i] & f) c++;
992 static int solve_count_clues_sub(game_state *state, int si, int id, int n,
993 int target, const char *what)
995 int ctrack = 0, cnotrack = 0, did = 0, j, i, w = state->p.w;
997 for (j = 0, i = si; j < n; j++, i += id) {
998 if (state->sflags[i] & S_TRACK)
1000 if (state->sflags[i] & S_NOTRACK)
1003 if (ctrack == target) {
1004 /* everything that's not S_TRACK must be S_NOTRACK. */
1005 for (j = 0, i = si; j < n; j++, i += id) {
1006 if (!(state->sflags[i] & S_TRACK))
1007 did += solve_set_sflag(state, i%w, i/w, S_NOTRACK, what);
1010 if (cnotrack == (n-target)) {
1011 /* everything that's not S_NOTRACK must be S_TRACK. */
1012 for (j = 0, i = si; j < n; j++, i += id) {
1013 if (!(state->sflags[i] & S_NOTRACK))
1014 did += solve_set_sflag(state, i%w, i/w, S_TRACK, what);
1020 static int solve_count_clues(game_state *state)
1022 int w = state->p.w, h = state->p.h, x, y, target, did = 0;
1024 for (x = 0; x < w; x++) {
1025 target = state->numbers->numbers[x];
1026 did += solve_count_clues_sub(state, x, w, h, target, "col count");
1028 for (y = 0; y < h; y++) {
1029 target = state->numbers->numbers[w+y];
1030 did += solve_count_clues_sub(state, y*w, 1, w, target, "row count");
1035 static int solve_check_single_sub(game_state *state, int si, int id, int n,
1036 int target, unsigned int perpf,
1039 int ctrack = 0, nperp = 0, did = 0, j, i, w = state->p.w;
1040 int n1edge = 0, i1edge = 0, ox, oy, x, y;
1041 unsigned int impossible = 0;
1043 /* For rows or columns which only have one more square to put a track in, we
1044 know the only way a new track section could be there would be to run
1045 perpendicular to the track (otherwise we'd need at least two free squares).
1046 So, if there is nowhere we can run perpendicular to the track (e.g. because
1047 we're on an edge) we know the extra track section much be on one end of an
1048 existing section. */
1050 for (j = 0, i = si; j < n; j++, i += id) {
1051 if (state->sflags[i] & S_TRACK)
1053 impossible = S_E_DIRS(state, i%w, i/w, E_NOTRACK);
1054 if ((perpf & impossible) == 0)
1056 if (S_E_COUNT(state, i%w, i/w, E_TRACK) <= 1) {
1061 if (ctrack != (target-1)) return 0;
1062 if (nperp > 0 || n1edge != 1) return 0;
1064 debug(("check_single from (%d,%d): 1 match from (%d,%d)",
1065 si%w, si/w, i1edge%w, i1edge/w));
1067 /* We have a match: anything that's more than 1 away from this square
1068 cannot now contain a track. */
1071 for (j = 0, i = si; j < n; j++, i += id) {
1074 if (abs(ox-x) > 1 || abs(oy-y) > 1) {
1075 if (!state->sflags[i] & S_TRACK)
1076 did += solve_set_sflag(state, x, y, S_NOTRACK, what);
1083 static int solve_check_single(game_state *state)
1085 int w = state->p.w, h = state->p.h, x, y, target, did = 0;
1087 for (x = 0; x < w; x++) {
1088 target = state->numbers->numbers[x];
1089 did += solve_check_single_sub(state, x, w, h, target, R|L, "single on col");
1091 for (y = 0; y < h; y++) {
1092 target = state->numbers->numbers[w+y];
1093 did += solve_check_single_sub(state, y*w, 1, w, target, U|D, "single on row");
1098 static int solve_check_loose_sub(game_state *state, int si, int id, int n,
1099 int target, unsigned int perpf,
1102 int nperp = 0, nloose = 0, e2count = 0, did = 0, i, j, k;
1104 unsigned int parf = ALLDIR & (~perpf);
1106 for (j = 0, i = si; j < n; j++, i += id) {
1107 int fcount = S_E_COUNT(state, i%w, i/w, E_TRACK);
1109 e2count++; /* this cell has 2 definite edges */
1110 state->sflags[i] &= ~S_MARK;
1111 if (fcount == 1 && (parf & S_E_DIRS(state, i%w, i/w, E_TRACK))) {
1112 nloose++; /* this cell has a loose end (single flag set parallel
1113 to the direction of this row/column) */
1114 state->sflags[i] |= S_MARK; /* mark loose ends */
1116 if (fcount != 2 && !(perpf & S_E_DIRS(state, i%w, i/w, E_NOTRACK)))
1117 nperp++; /* we could lay perpendicular across this cell */
1120 if (nloose > (target - e2count)) {
1121 debug(("check %s from (%d,%d): more loose (%d) than empty (%d), IMPOSSIBLE",
1122 what, si%w, si/w, nloose, target-e2count));
1123 state->impossible = TRUE;
1125 if (nloose > 0 && nloose == (target - e2count)) {
1126 debug(("check %s from (%d,%d): nloose = empty (%d), forcing loners out.",
1127 what, si%w, si/w, nloose));
1128 for (j = 0, i = si; j < n; j++, i += id) {
1129 if (!(state->sflags[i] & S_MARK))
1130 continue; /* skip non-loose ends */
1131 if (j > 0 && state->sflags[i-id] & S_MARK)
1132 continue; /* next to other loose end, could join up */
1133 if (j < (n-1) && state->sflags[i+id] & S_MARK)
1134 continue; /* ditto */
1136 for (k = 0; k < 4; k++) {
1137 if ((parf & (1<<k)) &&
1138 !(S_E_DIRS(state, i%w, i/w, E_TRACK) & (1<<k))) {
1139 /* set as NOTRACK the edge parallel to the row/column that's
1141 did += solve_set_eflag(state, i%w, i/w, 1<<k, E_NOTRACK, what);
1146 if (nloose == 1 && (target - e2count) == 2 && nperp == 0) {
1147 debug(("check %s from (%d,%d): 1 loose end, 2 empty squares, forcing parallel",
1149 for (j = 0, i = si; j < n; j++, i += id) {
1150 if (!(state->sflags[i] & S_MARK))
1151 continue; /* skip non-loose ends */
1152 for (k = 0; k < 4; k++) {
1154 did += solve_set_eflag(state, i%w, i/w, 1<<k, E_TRACK, what);
1162 static int solve_check_loose_ends(game_state *state)
1164 int w = state->p.w, h = state->p.h, x, y, target, did = 0;
1166 for (x = 0; x < w; x++) {
1167 target = state->numbers->numbers[x];
1168 did += solve_check_loose_sub(state, x, w, h, target, R|L, "loose on col");
1170 for (y = 0; y < h; y++) {
1171 target = state->numbers->numbers[w+y];
1172 did += solve_check_loose_sub(state, y*w, 1, w, target, U|D, "loose on row");
1177 static int solve_check_loop_sub(game_state *state, int x, int y, int dir,
1178 int *dsf, int startc, int endc)
1180 int w = state->p.w, h = state->p.h, i = y*w+x, j, k, satisfied = 1;
1182 j = (y+DY(dir))*w + (x+DX(dir));
1184 assert(i < w*h && j < w*h);
1186 if ((state->sflags[i] & S_TRACK) &&
1187 (state->sflags[j] & S_TRACK) &&
1188 !(S_E_DIRS(state, x, y, E_TRACK) & dir) &&
1189 !(S_E_DIRS(state, x, y, E_NOTRACK) & dir)) {
1190 int ic = dsf_canonify(dsf, i), jc = dsf_canonify(dsf, j);
1192 return solve_set_eflag(state, x, y, dir, E_NOTRACK, "would close loop");
1194 if ((ic == startc && jc == endc) || (ic == endc && jc == startc)) {
1195 debug(("Adding link at (%d,%d) would join start to end", x, y));
1196 /* We mustn't join the start to the end if:
1197 - there are other bits of track that aren't attached to either end
1198 - the clues are not fully satisfied yet
1200 for (k = 0; k < w*h; k++) {
1201 if (state->sflags[k] & S_TRACK &&
1202 dsf_canonify(dsf, k) != startc && dsf_canonify(dsf, k) != endc) {
1203 return solve_set_eflag(state, x, y, dir, E_NOTRACK,
1204 "joins start to end but misses tracks");
1207 for (k = 0; k < w; k++) {
1208 int target = state->numbers->numbers[k];
1209 int ntracks = solve_count_col(state, k, S_TRACK);
1210 if (ntracks < target) satisfied = 0;
1212 for (k = 0; k < h; k++) {
1213 int target = state->numbers->numbers[w+k];
1214 int ntracks = solve_count_row(state, k, S_TRACK);
1215 if (ntracks < target) satisfied = 0;
1218 return solve_set_eflag(state, x, y, dir, E_NOTRACK,
1219 "joins start to end with incomplete clues");
1226 static int solve_check_loop(game_state *state)
1228 int w = state->p.w, h = state->p.h, x, y, i, j, did = 0;
1229 int *dsf, startc, endc;
1231 /* TODO eventually we should pull this out into a solver struct and keep it
1232 updated as we connect squares. For now we recreate it every time we try
1233 this particular solver step. */
1234 dsf = snewn(w*h, int);
1237 /* Work out the connectedness of the current loop set. */
1238 for (x = 0; x < w; x++) {
1239 for (y = 0; y < h; y++) {
1241 if (x < (w-1) && S_E_DIRS(state, x, y, E_TRACK) & R) {
1242 /* connection to the right... */
1244 assert(i < w*h && j < w*h);
1245 dsf_merge(dsf, i, j);
1247 if (y < (h-1) && S_E_DIRS(state, x, y, E_TRACK) & D) {
1248 /* connection down... */
1250 assert(i < w*h && j < w*h);
1251 dsf_merge(dsf, i, j);
1253 /* NB no need to check up and left because they'll have been checked
1254 by the other side. */
1258 startc = dsf_canonify(dsf, state->numbers->row_s*w);
1259 endc = dsf_canonify(dsf, (h-1)*w+state->numbers->col_s);
1261 /* Now look at all adjacent squares that are both S_TRACK: if connecting
1262 any of them would complete a loop (i.e. they're both the same dsf class
1263 already) then that edge must be NOTRACK. */
1264 for (x = 0; x < w; x++) {
1265 for (y = 0; y < h; y++) {
1267 did += solve_check_loop_sub(state, x, y, R, dsf, startc, endc);
1269 did += solve_check_loop_sub(state, x, y, D, dsf, startc, endc);
1278 static void solve_discount_edge(game_state *state, int x, int y, int d)
1280 if (S_E_DIRS(state, x, y, E_TRACK) & d) {
1281 assert(state->sflags[y*state->p.w + x] & S_CLUE);
1282 return; /* (only) clue squares can have outer edges set. */
1284 solve_set_eflag(state, x, y, d, E_NOTRACK, "outer edge");
1287 static int tracks_solve(game_state *state, int diff)
1289 int didsth, x, y, w = state->p.w, h = state->p.h;
1291 debug(("solve..."));
1292 state->impossible = FALSE;
1294 /* Set all the outer border edges as no-track. */
1295 for (x = 0; x < w; x++) {
1296 solve_discount_edge(state, x, 0, U);
1297 solve_discount_edge(state, x, h-1, D);
1299 for (y = 0; y < h; y++) {
1300 solve_discount_edge(state, 0, y, L);
1301 solve_discount_edge(state, w-1, y, R);
1307 didsth += solve_update_flags(state);
1308 didsth += solve_count_clues(state);
1309 didsth += solve_check_loop(state);
1311 if (diff >= DIFF_TRICKY) {
1312 didsth += solve_check_single(state);
1313 didsth += solve_check_loose_ends(state);
1316 if (!didsth || state->impossible) break;
1319 return state->impossible ? -1 : check_completion(state, FALSE) ? 1 : 0;
1322 static char *move_string_diff(const game_state *before, const game_state *after, int issolve)
1324 int w = after->p.w, h = after->p.h, i, j;
1325 char *move = snewn(w*h*40, char), *p = move;
1326 const char *sep = "";
1327 unsigned int otf, ntf, onf, nnf;
1333 for (i = 0; i < w*h; i++) {
1334 otf = S_E_DIRS(before, i%w, i/w, E_TRACK);
1335 ntf = S_E_DIRS(after, i%w, i/w, E_TRACK);
1336 onf = S_E_DIRS(before, i%w, i/w, E_NOTRACK);
1337 nnf = S_E_DIRS(after, i%w, i/w, E_NOTRACK);
1339 for (j = 0; j < 4; j++) {
1341 if ((otf & df) != (ntf & df)) {
1342 p += sprintf(p, "%s%c%c%d,%d", sep,
1343 (ntf & df) ? 'T' : 't', MOVECHAR(df), i%w, i/w);
1346 if ((onf & df) != (nnf & df)) {
1347 p += sprintf(p, "%s%c%c%d,%d", sep,
1348 (nnf & df) ? 'N' : 'n', MOVECHAR(df), i%w, i/w);
1353 if ((before->sflags[i] & S_NOTRACK) != (after->sflags[i] & S_NOTRACK)) {
1354 p += sprintf(p, "%s%cS%d,%d", sep,
1355 (after->sflags[i] & S_NOTRACK) ? 'N' : 'n', i%w, i/w);
1358 if ((before->sflags[i] & S_TRACK) != (after->sflags[i] & S_TRACK)) {
1359 p += sprintf(p, "%s%cS%d,%d", sep,
1360 (after->sflags[i] & S_TRACK) ? 'T' : 't', i%w, i/w);
1365 move = sresize(move, p - move, char);
1370 static char *solve_game(const game_state *state, const game_state *currstate,
1371 const char *aux, char **error)
1377 solved = dup_game(currstate);
1378 ret = tracks_solve(solved, DIFFCOUNT);
1381 solved = dup_game(state);
1382 ret = tracks_solve(solved, DIFFCOUNT);
1386 *error = "Unable to find solution";
1389 move = move_string_diff(currstate, solved, TRUE);
1396 static int game_can_format_as_text_now(const game_params *params)
1401 static char *game_text_format(const game_state *state)
1404 int x, y, len, w = state->p.w, h = state->p.h;
1406 len = ((w*2) + 4) * ((h*2)+4) + 2;
1407 ret = snewn(len+1, char);
1410 /* top line: column clues */
1413 for (x = 0; x < w; x++) {
1414 *p++ = (state->numbers->numbers[x] < 10 ?
1415 '0' + state->numbers->numbers[x] :
1416 'A' + state->numbers->numbers[x] - 10);
1421 /* second line: top edge */
1424 for (x = 0; x < w*2-1; x++)
1429 /* grid rows: one line of squares, one line of edges. */
1430 for (y = 0; y < h; y++) {
1431 /* grid square line */
1432 *p++ = (y == state->numbers->row_s) ? 'A' : ' ';
1433 *p++ = (y == state->numbers->row_s) ? '-' : '|';
1435 for (x = 0; x < w; x++) {
1436 unsigned int f = S_E_DIRS(state, x, y, E_TRACK);
1437 if (state->sflags[y*w+x] & S_CLUE) *p++ = 'C';
1438 else if (f == LU || f == RD) *p++ = '/';
1439 else if (f == LD || f == RU) *p++ = '\\';
1440 else if (f == UD) *p++ = '|';
1441 else if (f == RL) *p++ = '-';
1442 else if (state->sflags[y*w+x] & S_NOTRACK) *p++ = 'x';
1446 *p++ = (f & R) ? '-' : ' ';
1450 *p++ = (state->numbers->numbers[w+y] < 10 ?
1451 '0' + state->numbers->numbers[w+y] :
1452 'A' + state->numbers->numbers[w+y] - 10);
1455 if (y == h-1) continue;
1460 for (x = 0; x < w; x++) {
1461 unsigned int f = S_E_DIRS(state, x, y, E_TRACK);
1462 *p++ = (f & D) ? '|' : ' ';
1463 *p++ = (x < w-1) ? ' ' : '|';
1468 /* next line: bottom edge */
1471 for (x = 0; x < w*2-1; x++)
1472 *p++ = (x == state->numbers->col_s*2) ? '|' : '-';
1476 /* final line: bottom clue */
1479 for (x = 0; x < w*2-1; x++)
1480 *p++ = (x == state->numbers->col_s*2) ? 'B' : ' ';
1487 static void debug_state(game_state *state, const char *what) {
1488 char *sstring = game_text_format(state);
1489 debug(("%s: %s", what, sstring));
1493 static void dsf_update_completion(game_state *state, int ax, int ay,
1496 int w = state->p.w, ai = ay*w+ax, bx, by, bi;
1498 if (!(S_E_DIRS(state, ax, ay, E_TRACK) & dir)) return;
1502 if (!INGRID(state, bx, by)) return;
1505 dsf_merge(dsf, ai, bi);
1508 struct tracks_neighbour_ctx {
1510 int i, n, neighbours[4];
1512 static int tracks_neighbour(int vertex, void *vctx)
1514 struct tracks_neighbour_ctx *ctx = (struct tracks_neighbour_ctx *)vctx;
1516 game_state *state = ctx->state;
1517 int w = state->p.w, x = vertex % w, y = vertex / w;
1518 int dirs = S_E_DIRS(state, x, y, E_TRACK);
1521 ctx->i = ctx->n = 0;
1523 for (j = 0; j < 4; j++) {
1526 int nx = x + DX(dir), ny = y + DY(dir);
1527 if (INGRID(state, nx, ny))
1528 ctx->neighbours[ctx->n++] = ny * w + nx;
1533 if (ctx->i < ctx->n)
1534 return ctx->neighbours[ctx->i++];
1539 static int check_completion(game_state *state, int mark)
1541 int w = state->p.w, h = state->p.h, x, y, i, target, ret = TRUE;
1542 int ntrack, nnotrack, ntrackcomplete;
1543 int *dsf, pathclass;
1544 struct findloopstate *fls;
1545 struct tracks_neighbour_ctx ctx;
1548 for (i = 0; i < w+h; i++) {
1549 state->num_errors[i] = 0;
1551 for (i = 0; i < w*h; i++) {
1552 state->sflags[i] &= ~S_ERROR;
1553 if (S_E_COUNT(state, i%w, i/w, E_TRACK) > 0) {
1554 if (S_E_COUNT(state, i%w, i/w, E_TRACK) > 2)
1555 state->sflags[i] |= S_ERROR;
1560 /* A cell is 'complete', for the purposes of marking the game as
1561 * finished, if it has two edges marked as TRACK. But it only has
1562 * to have one edge marked as TRACK, or be filled in as trackful
1563 * without any specific edges known, to count towards checking
1564 * row/column clue errors. */
1565 for (x = 0; x < w; x++) {
1566 target = state->numbers->numbers[x];
1567 ntrack = nnotrack = ntrackcomplete = 0;
1568 for (y = 0; y < h; y++) {
1569 if (S_E_COUNT(state, x, y, E_TRACK) > 0 ||
1570 state->sflags[y*w+x] & S_TRACK)
1572 if (S_E_COUNT(state, x, y, E_TRACK) == 2)
1574 if (state->sflags[y*w+x] & S_NOTRACK)
1578 if (ntrack > target || nnotrack > (h-target)) {
1579 debug(("col %d error: target %d, track %d, notrack %d",
1580 x, target, ntrack, nnotrack));
1581 state->num_errors[x] = 1;
1584 if (ntrackcomplete != target)
1587 for (y = 0; y < h; y++) {
1588 target = state->numbers->numbers[w+y];
1589 ntrack = nnotrack = ntrackcomplete = 0;
1590 for (x = 0; x < w; x++) {
1591 if (S_E_COUNT(state, x, y, E_TRACK) > 0 ||
1592 state->sflags[y*w+x] & S_TRACK)
1594 if (S_E_COUNT(state, x, y, E_TRACK) == 2)
1596 if (state->sflags[y*w+x] & S_NOTRACK)
1600 if (ntrack > target || nnotrack > (w-target)) {
1601 debug(("row %d error: target %d, track %d, notrack %d",
1602 y, target, ntrack, nnotrack));
1603 state->num_errors[w+y] = 1;
1606 if (ntrackcomplete != target)
1610 dsf = snewn(w*h, int);
1613 for (x = 0; x < w; x++) {
1614 for (y = 0; y < h; y++) {
1615 dsf_update_completion(state, x, y, R, dsf);
1616 dsf_update_completion(state, x, y, D, dsf);
1620 fls = findloop_new_state(w*h);
1622 if (findloop_run(fls, w*h, tracks_neighbour, &ctx)) {
1623 debug(("loop detected, not complete"));
1624 ret = FALSE; /* no loop allowed */
1626 for (x = 0; x < w; x++) {
1627 for (y = 0; y < h; y++) {
1631 for (v = tracks_neighbour(u, &ctx); v >= 0;
1632 v = tracks_neighbour(-1, &ctx))
1633 if (findloop_is_loop_edge(fls, u, v))
1634 state->sflags[y*w+x] |= S_ERROR;
1639 findloop_free_state(fls);
1642 pathclass = dsf_canonify(dsf, state->numbers->row_s*w);
1643 if (pathclass == dsf_canonify(dsf, (h-1)*w + state->numbers->col_s)) {
1644 /* We have a continuous path between the entrance and the exit: any
1645 other path must be in error. */
1646 for (i = 0; i < w*h; i++) {
1647 if ((dsf_canonify(dsf, i) != pathclass) &&
1648 ((state->sflags[i] & S_TRACK) ||
1649 (S_E_COUNT(state, i%w, i/w, E_TRACK) > 0)))
1650 state->sflags[i] |= S_ERROR;
1656 state->completed = ret;
1661 /* Code borrowed from Pearl. */
1664 int dragging, clearing, notrack;
1665 int drag_sx, drag_sy, drag_ex, drag_ey; /* drag start and end grid coords */
1666 int clickx, clicky; /* pixel position of initial click */
1668 int curx, cury; /* grid position of keyboard cursor; uses half-size grid */
1669 int cursor_active; /* TRUE iff cursor is shown */
1672 static game_ui *new_ui(const game_state *state)
1674 game_ui *ui = snew(game_ui);
1676 ui->clearing = ui->notrack = ui->dragging = 0;
1677 ui->drag_sx = ui->drag_sy = ui->drag_ex = ui->drag_ey = -1;
1678 ui->cursor_active = FALSE;
1679 ui->curx = ui->cury = 1;
1684 static void free_ui(game_ui *ui)
1689 static char *encode_ui(const game_ui *ui)
1694 static void decode_ui(game_ui *ui, const char *encoding)
1698 static void game_changed_state(game_ui *ui, const game_state *oldstate,
1699 const game_state *newstate)
1703 #define PREFERRED_TILE_SIZE 30
1704 #define HALFSZ (ds->sz6*3)
1705 #define THIRDSZ (ds->sz6*2)
1706 #define TILE_SIZE (ds->sz6*6)
1708 #define BORDER (TILE_SIZE/8)
1709 #define BORDER_WIDTH (max(TILE_SIZE / 32, 1))
1711 #define COORD(x) ( (x+1) * TILE_SIZE + BORDER )
1712 #define CENTERED_COORD(x) ( COORD(x) + TILE_SIZE/2 )
1713 #define FROMCOORD(x) ( ((x) < BORDER) ? -1 : ( ((x) - BORDER) / TILE_SIZE) - 1 )
1715 #define DS_DSHIFT 4 /* R/U/L/D shift, for drag-in-progress flags */
1717 #define DS_ERROR (1 << 8)
1718 #define DS_CLUE (1 << 9)
1719 #define DS_NOTRACK (1 << 10)
1720 #define DS_FLASH (1 << 11)
1721 #define DS_CURSOR (1 << 12) /* cursor in square (centre, or on edge) */
1722 #define DS_TRACK (1 << 13)
1723 #define DS_CLEARING (1 << 14)
1725 #define DS_NSHIFT 16 /* R/U/L/D shift, for no-track edge flags */
1726 #define DS_CSHIFT 20 /* R/U/L/D shift, for cursor-on-edge */
1728 struct game_drawstate {
1733 unsigned int *flags, *flags_drag;
1737 static void update_ui_drag(const game_state *state, game_ui *ui, int gx, int gy)
1739 int w = state->p.w, h = state->p.h;
1740 int dx = abs(ui->drag_sx - gx), dy = abs(ui->drag_sy - gy);
1743 ui->drag_ex = gx < 0 ? 0 : gx >= w ? w-1 : gx;
1744 ui->drag_ey = ui->drag_sy;
1745 ui->dragging = TRUE;
1746 } else if (dx == 0) {
1747 ui->drag_ex = ui->drag_sx;
1748 ui->drag_ey = gy < 0 ? 0 : gy >= h ? h-1 : gy;
1749 ui->dragging = TRUE;
1751 ui->drag_ex = ui->drag_sx;
1752 ui->drag_ey = ui->drag_sy;
1753 ui->dragging = FALSE;
1757 static int ui_can_flip_edge(const game_state *state, int x, int y, int dir,
1760 int w = state->p.w /*, h = state->shared->h, sz = state->shared->sz */;
1761 int x2 = x + DX(dir);
1762 int y2 = y + DY(dir);
1763 unsigned int sf1, sf2, ef;
1765 if (!INGRID(state, x, y) || !INGRID(state, x2, y2))
1768 sf1 = state->sflags[y*w + x];
1769 sf2 = state->sflags[y2*w + x2];
1770 if ( !notrack && ((sf1 & S_CLUE) || (sf2 & S_CLUE)) )
1773 ef = S_E_FLAGS(state, x, y, dir);
1775 /* if we're going to _set_ NOTRACK (i.e. the flag is currently unset),
1776 make sure the edge is not already set to TRACK. The adjacent squares
1777 could be set to TRACK, because we don't know which edges the general
1778 square setting refers to. */
1779 if (!(ef & E_NOTRACK) && (ef & E_TRACK))
1782 if (!(ef & E_TRACK)) {
1783 /* if we're going to _set_ TRACK, make sure neither adjacent square nor
1784 the edge itself is already set to NOTRACK. */
1785 if ((sf1 & S_NOTRACK) || (sf2 & S_NOTRACK) || (ef & E_NOTRACK))
1787 /* if we're going to _set_ TRACK, make sure neither adjacent square has
1788 2 track flags already. */
1789 if ((S_E_COUNT(state, x, y, E_TRACK) >= 2) ||
1790 (S_E_COUNT(state, x2, y2, E_TRACK) >= 2))
1797 static int ui_can_flip_square(const game_state *state, int x, int y, int notrack)
1799 int w = state->p.w, trackc;
1802 if (!INGRID(state, x, y)) return FALSE;
1803 sf = state->sflags[y*w+x];
1804 trackc = S_E_COUNT(state, x, y, E_TRACK);
1806 if (sf & S_CLUE) return FALSE;
1809 /* If we're setting S_NOTRACK, we cannot have either S_TRACK or any E_TRACK. */
1810 if (!(sf & S_NOTRACK) && ((sf & S_TRACK) || (trackc > 0)))
1813 /* If we're setting S_TRACK, we cannot have any S_NOTRACK (we could have
1814 E_NOTRACK, though, because one or two wouldn't rule out a track) */
1815 if (!(sf & S_TRACK) && (sf & S_NOTRACK))
1821 static char *edge_flip_str(const game_state *state, int x, int y, int dir, int notrack, char *buf) {
1822 unsigned ef = S_E_FLAGS(state, x, y, dir);
1826 c = (ef & E_NOTRACK) ? 'n' : 'N';
1828 c = (ef & E_TRACK) ? 't' : 'T';
1830 sprintf(buf, "%c%c%d,%d", c, MOVECHAR(dir), x, y);
1834 static char *square_flip_str(const game_state *state, int x, int y, int notrack, char *buf) {
1835 unsigned f = state->sflags[y*state->p.w+x];
1839 c = (f & E_NOTRACK) ? 'n' : 'N';
1841 c = (f & E_TRACK) ? 't' : 'T';
1843 sprintf(buf, "%cS%d,%d", c, x, y);
1847 #define SIGN(x) ((x<0) ? -1 : (x>0))
1849 static game_state *copy_and_apply_drag(const game_state *state, const game_ui *ui)
1851 game_state *after = dup_game(state);
1852 int x1, y1, x2, y2, x, y, w = state->p.w;
1853 unsigned f = ui->notrack ? S_NOTRACK : S_TRACK, ff;
1855 x1 = min(ui->drag_sx, ui->drag_ex); x2 = max(ui->drag_sx, ui->drag_ex);
1856 y1 = min(ui->drag_sy, ui->drag_ey); y2 = max(ui->drag_sy, ui->drag_ey);
1858 /* actually either x1 == x2, or y1 == y2, but it's easier just to code
1860 for (x = x1; x <= x2; x++) {
1861 for (y = y1; y <= y2; y++) {
1862 ff = state->sflags[y*w+x];
1863 if (ui->clearing && !(ff & f))
1864 continue; /* nothing to do, clearing and already clear */
1865 else if (!ui->clearing && (ff & f))
1866 continue; /* nothing to do, setting and already set */
1867 else if (ui_can_flip_square(state, x, y, ui->notrack))
1868 after->sflags[y*w+x] ^= f;
1874 #define KEY_DIRECTION(btn) (\
1875 (btn) == CURSOR_DOWN ? D : (btn) == CURSOR_UP ? U :\
1876 (btn) == CURSOR_LEFT ? L : R)
1878 static char *interpret_move(const game_state *state, game_ui *ui,
1879 const game_drawstate *ds,
1880 int x, int y, int button)
1882 int w = state->p.w, h = state->p.h, direction;
1883 int gx = FROMCOORD(x), gy = FROMCOORD(y);
1886 /* --- mouse operations --- */
1888 if (IS_MOUSE_DOWN(button)) {
1889 ui->cursor_active = FALSE;
1890 ui->dragging = FALSE;
1892 if (!INGRID(state, gx, gy)) {
1893 /* can't drag from off grid */
1897 if (button == RIGHT_BUTTON) {
1899 ui->clearing = state->sflags[gy*w+gx] & S_NOTRACK;
1901 ui->notrack = FALSE;
1902 ui->clearing = state->sflags[gy*w+gx] & S_TRACK;
1907 ui->drag_sx = ui->drag_ex = gx;
1908 ui->drag_sy = ui->drag_ey = gy;
1913 if (IS_MOUSE_DRAG(button)) {
1914 ui->cursor_active = FALSE;
1915 update_ui_drag(state, ui, gx, gy);
1919 if (IS_MOUSE_RELEASE(button)) {
1920 ui->cursor_active = FALSE;
1922 (ui->drag_sx != ui->drag_ex || ui->drag_sy != ui->drag_ey)) {
1923 game_state *dragged = copy_and_apply_drag(state, ui);
1924 char *ret = move_string_diff(state, dragged, FALSE);
1933 /* We might still have been dragging (and just done a one-
1934 * square drag): cancel drag, so undo doesn't make it like
1935 * a drag-in-progress. */
1938 /* Click (or tiny drag). Work out which edge we were
1942 * We process clicks based on the mouse-down location,
1943 * because that's more natural for a user to carefully
1944 * control than the mouse-up.
1949 cx = CENTERED_COORD(gx);
1950 cy = CENTERED_COORD(gy);
1952 if (!INGRID(state, gx, gy) || FROMCOORD(x) != gx || FROMCOORD(y) != gy)
1955 if (max(abs(x-cx),abs(y-cy)) < TILE_SIZE/4) {
1956 if (ui_can_flip_square(state, gx, gy, button == RIGHT_RELEASE))
1957 return square_flip_str(state, gx, gy, button == RIGHT_RELEASE, tmpbuf);
1960 if (abs(x-cx) < abs(y-cy)) {
1961 /* Closest to top/bottom edge. */
1962 direction = (y < cy) ? U : D;
1964 /* Closest to left/right edge. */
1965 direction = (x < cx) ? L : R;
1967 if (ui_can_flip_edge(state, gx, gy, direction,
1968 button == RIGHT_RELEASE))
1969 return edge_flip_str(state, gx, gy, direction,
1970 button == RIGHT_RELEASE, tmpbuf);
1977 /* --- cursor/keyboard operations --- */
1979 if (IS_CURSOR_MOVE(button)) {
1980 int dx = (button == CURSOR_LEFT) ? -1 : ((button == CURSOR_RIGHT) ? +1 : 0);
1981 int dy = (button == CURSOR_DOWN) ? +1 : ((button == CURSOR_UP) ? -1 : 0);
1983 if (!ui->cursor_active) {
1984 ui->cursor_active = TRUE;
1988 ui->curx = ui->curx + dx;
1989 ui->cury = ui->cury + dy;
1990 if ((ui->curx % 2 == 0) && (ui->cury % 2 == 0)) {
1991 /* disallow cursor on square corners: centres and edges only */
1992 ui->curx += dx; ui->cury += dy;
1994 ui->curx = min(max(ui->curx, 1), 2*w-1);
1995 ui->cury = min(max(ui->cury, 1), 2*h-1);
1999 if (IS_CURSOR_SELECT(button)) {
2000 if (!ui->cursor_active) {
2001 ui->cursor_active = TRUE;
2004 /* click on square corner does nothing (shouldn't get here) */
2005 if ((ui->curx % 2) == 0 && (ui->cury % 2 == 0))
2010 direction = ((ui->curx % 2) == 0) ? L : ((ui->cury % 2) == 0) ? U : 0;
2013 ui_can_flip_edge(state, gx, gy, direction, button == CURSOR_SELECT2))
2014 return edge_flip_str(state, gx, gy, direction, button == CURSOR_SELECT2, tmpbuf);
2015 else if (!direction &&
2016 ui_can_flip_square(state, gx, gy, button == CURSOR_SELECT2))
2017 return square_flip_str(state, gx, gy, button == CURSOR_SELECT2, tmpbuf);
2022 /* helps to debug the solver */
2023 if (button == 'H' || button == 'h')
2030 static game_state *execute_move(const game_state *state, const char *move)
2032 int w = state->p.w, x, y, n, i;
2035 game_state *ret = dup_game(state);
2037 /* this is breaking the bank on GTK, which vsprintf's into a fixed-size buffer
2038 * which is 4096 bytes long. vsnprintf needs a feature-test macro to use, faff. */
2039 /*debug(("move: %s\n", move));*/
2044 ret->used_solve = TRUE;
2046 } else if (c == 'T' || c == 't' || c == 'N' || c == 'n') {
2047 /* set track, clear track; set notrack, clear notrack */
2049 if (sscanf(move, "%c%d,%d%n", &d, &x, &y, &n) != 3)
2051 if (!INGRID(state, x, y)) goto badmove;
2053 f = (c == 'T' || c == 't') ? S_TRACK : S_NOTRACK;
2056 if (c == 'T' || c == 'N')
2057 ret->sflags[y*w+x] |= f;
2059 ret->sflags[y*w+x] &= ~f;
2060 } else if (d == 'U' || d == 'D' || d == 'L' || d == 'R') {
2061 for (i = 0; i < 4; i++) {
2064 if (MOVECHAR(df) == d) {
2065 if (c == 'T' || c == 'N')
2066 S_E_SET(ret, x, y, df, f);
2068 S_E_CLEAR(ret, x, y, df, f);
2074 } else if (c == 'H') {
2075 tracks_solve(ret, DIFFCOUNT);
2086 check_completion(ret, TRUE);
2095 /* ----------------------------------------------------------------------
2099 #define FLASH_TIME 0.5F
2101 static void game_compute_size(const game_params *params, int tilesize,
2104 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
2108 ads.sz6 = tilesize/6;
2110 *x = (params->w+2) * TILE_SIZE + 2 * BORDER;
2111 *y = (params->h+2) * TILE_SIZE + 2 * BORDER;
2114 static void game_set_size(drawing *dr, game_drawstate *ds,
2115 const game_params *params, int tilesize)
2117 ds->sz6 = tilesize/6;
2121 COL_BACKGROUND, COL_LOWLIGHT, COL_HIGHLIGHT,
2122 COL_TRACK_BACKGROUND = COL_LOWLIGHT,
2123 COL_GRID, COL_CLUE, COL_CURSOR,
2124 COL_TRACK, COL_TRACK_CLUE, COL_SLEEPER,
2125 COL_DRAGON, COL_DRAGOFF,
2126 COL_ERROR, COL_FLASH,
2130 static float *game_colours(frontend *fe, int *ncolours)
2132 float *ret = snewn(3 * NCOLOURS, float);
2135 game_mkhighlight(fe, ret, COL_BACKGROUND, COL_HIGHLIGHT, COL_LOWLIGHT);
2137 for (i = 0; i < 3; i++) {
2138 ret[COL_TRACK_CLUE * 3 + i] = 0.0F;
2139 ret[COL_TRACK * 3 + i] = 0.5F;
2140 ret[COL_CLUE * 3 + i] = 0.0F;
2141 ret[COL_GRID * 3 + i] = 0.75F;
2142 ret[COL_CURSOR * 3 + i] = 0.6F;
2145 ret[COL_SLEEPER * 3 + 0] = 0.5F;
2146 ret[COL_SLEEPER * 3 + 1] = 0.4F;
2147 ret[COL_SLEEPER * 3 + 2] = 0.1F;
2149 ret[COL_ERROR * 3 + 0] = 1.0F;
2150 ret[COL_ERROR * 3 + 1] = 0.0F;
2151 ret[COL_ERROR * 3 + 2] = 0.0F;
2153 ret[COL_DRAGON * 3 + 0] = 0.0F;
2154 ret[COL_DRAGON * 3 + 1] = 0.0F;
2155 ret[COL_DRAGON * 3 + 2] = 1.0F;
2157 ret[COL_DRAGOFF * 3 + 0] = 0.8F;
2158 ret[COL_DRAGOFF * 3 + 1] = 0.8F;
2159 ret[COL_DRAGOFF * 3 + 2] = 1.0F;
2161 ret[COL_FLASH * 3 + 0] = 1.0F;
2162 ret[COL_FLASH * 3 + 1] = 1.0F;
2163 ret[COL_FLASH * 3 + 2] = 1.0F;
2165 *ncolours = NCOLOURS;
2169 static game_drawstate *game_new_drawstate(drawing *dr, const game_state *state)
2171 struct game_drawstate *ds = snew(struct game_drawstate);
2175 ds->started = FALSE;
2179 ds->sz = ds->w*ds->h;
2180 ds->flags = snewn(ds->sz, unsigned int);
2181 ds->flags_drag = snewn(ds->sz, unsigned int);
2182 for (i = 0; i < ds->sz; i++)
2183 ds->flags[i] = ds->flags_drag[i] = 0;
2185 ds->num_errors = snewn(ds->w+ds->h, int);
2186 for (i = 0; i < ds->w+ds->h; i++)
2187 ds->num_errors[i] = 0;
2192 static void game_free_drawstate(drawing *dr, game_drawstate *ds)
2195 sfree(ds->flags_drag);
2196 sfree(ds->num_errors);
2200 static void draw_circle_sleepers(drawing *dr, game_drawstate *ds,
2201 float cx, float cy, float r2, float thickness, int c)
2203 float qr6 = (float)PI/12, qr3 = (float)PI/6, th, x1, y1, x2, y2;
2204 float t6 = THIRDSZ/2.0F, r1 = t6;
2207 for (i = 0; i < 12; i++) {
2209 x1 = r1*(float)cos(th);
2210 x2 = r2*(float)cos(th);
2211 y1 = r1*(float)sin(th);
2212 y2 = r2*(float)sin(th);
2213 draw_thick_line(dr, thickness, cx+x1, cy+y1, cx+x2, cy+y2, c);
2217 static void draw_thick_circle_outline(drawing *dr, float thickness,
2218 float cx, float cy, float r,
2221 float circ4 = 0.5F * (float)PI * r, ang, x1, y1, x2, y2;
2224 nseg = (int)(circ4 / 4.0F)*4; /* ensure a quarter-circle has a whole #segs */
2225 ang = 2.0F*(float)PI / nseg;
2227 for (i = 0; i < nseg; i++) {
2228 float th = ang * i, th2 = ang * (i+1);
2229 x1 = cx + r*(float)cos(th);
2230 x2 = cx + r*(float)cos(th2);
2231 y1 = cy + r*(float)sin(th);
2232 y2 = cy + r*(float)sin(th2);
2233 debug(("circ outline: x=%.2f -> %.2f, thick=%.2f", x1, x2, thickness));
2234 draw_thick_line(dr, thickness, x1, y1, x2, y2, colour);
2238 static void draw_tracks_specific(drawing *dr, game_drawstate *ds,
2239 int x, int y, unsigned int flags,
2240 int ctrack, int csleeper)
2242 float ox = (float)COORD(x), oy = (float)COORD(y), cx, cy;
2243 float t1 = (float)TILE_SIZE, t3 = TILE_SIZE/3.0F, t6 = TILE_SIZE/6.0F;
2245 float thick_track = TILE_SIZE/8.0F, thick_sleeper = TILE_SIZE/12.0F;
2248 for (i = 1; i <= 7; i+=2) {
2249 cx = ox + TILE_SIZE/8.0F*i;
2250 draw_thick_line(dr, thick_sleeper,
2251 cx, oy+t6, cx, oy+t6+2*t3, csleeper);
2253 draw_thick_line(dr, thick_track, ox, oy + t3, ox + TILE_SIZE, oy + t3, ctrack);
2254 draw_thick_line(dr, thick_track, ox, oy + 2*t3, ox + TILE_SIZE, oy + 2*t3, ctrack);
2258 for (i = 1; i <= 7; i+=2) {
2259 cy = oy + TILE_SIZE/8.0F*i;
2260 draw_thick_line(dr, thick_sleeper,
2261 ox+t6, cy, ox+t6+2*t3, cy, csleeper);
2263 debug(("vert line: x=%.2f, thick=%.2f", ox + t3, thick_track));
2264 draw_thick_line(dr, thick_track, ox + t3, oy, ox + t3, oy + TILE_SIZE, ctrack);
2265 draw_thick_line(dr, thick_track, ox + 2*t3, oy, ox + 2*t3, oy + TILE_SIZE, ctrack);
2268 if (flags == UL || flags == DL || flags == UR || flags == DR) {
2269 cx = (flags & L) ? ox : ox + TILE_SIZE;
2270 cy = (flags & U) ? oy : oy + TILE_SIZE;
2272 draw_circle_sleepers(dr, ds, cx, cy, (float)(5*t6), thick_sleeper, csleeper);
2274 draw_thick_circle_outline(dr, thick_track, (float)cx, (float)cy,
2276 draw_thick_circle_outline(dr, thick_track, (float)cx, (float)cy,
2282 for (d = 1; d < 16; d *= 2) {
2283 float ox1 = 0, ox2 = 0, oy1 = 0, oy2 = 0;
2285 if (!(flags & d)) continue;
2287 for (i = 1; i <= 2; i++) {
2292 } else if (d == R) {
2294 ox2 = t1 - thick_track;
2296 } else if (d == U) {
2300 } else if (d == D) {
2303 oy2 = t1 - thick_track;
2305 draw_thick_line(dr, thick_track, ox+ox1, oy+oy1, ox+ox2, oy+oy2, ctrack);
2310 static unsigned int best_bits(unsigned int flags, unsigned int flags_drag, int *col)
2312 int nb_orig = nbits[flags & ALLDIR], nb_drag = nbits[flags_drag & ALLDIR];
2314 if (nb_orig > nb_drag) {
2316 return flags & ALLDIR;
2317 } else if (nb_orig < nb_drag) {
2319 return flags_drag & ALLDIR;
2321 return flags & ALLDIR; /* same number of bits: no special colour. */
2324 static void draw_square(drawing *dr, game_drawstate *ds,
2325 int x, int y, unsigned int flags, unsigned int flags_drag)
2327 int t2 = HALFSZ, t16 = HALFSZ/4, off;
2328 int ox = COORD(x), oy = COORD(y), cx = ox + t2, cy = oy + t2, d, c;
2329 int bg = (flags & DS_TRACK) ? COL_TRACK_BACKGROUND : COL_BACKGROUND;
2330 unsigned int flags_best;
2334 /* Clip to the grid square. */
2335 clip(dr, ox, oy, TILE_SIZE, TILE_SIZE);
2337 /* Clear the square. */
2338 best_bits((flags & DS_TRACK) == DS_TRACK,
2339 (flags_drag & DS_TRACK) == DS_TRACK, &bg);
2340 draw_rect(dr, ox, oy, TILE_SIZE, TILE_SIZE, bg);
2342 /* Draw outline of grid square */
2343 draw_line(dr, ox, oy, COORD(x+1), oy, COL_GRID);
2344 draw_line(dr, ox, oy, ox, COORD(y+1), COL_GRID);
2346 /* More outlines for clue squares. */
2347 if (flags & DS_CURSOR) {
2348 int curx, cury, curw, curh;
2351 curx = ox + off; cury = oy + off;
2352 curw = curh = TILE_SIZE - (2*off) + 1;
2354 if (flags & (U << DS_CSHIFT)) {
2355 cury = oy - off; curh = 2*off + 1;
2356 } else if (flags & (D << DS_CSHIFT)) {
2357 cury = oy + TILE_SIZE - off; curh = 2*off + 1;
2358 } else if (flags & (L << DS_CSHIFT)) {
2359 curx = ox - off; curw = 2*off + 1;
2360 } else if (flags & (R << DS_CSHIFT)) {
2361 curx = ox + TILE_SIZE - off; curw = 2*off + 1;
2364 draw_rect_outline(dr, curx, cury, curw, curh, COL_GRID);
2367 /* Draw tracks themselves */
2368 c = (flags & DS_ERROR) ? COL_ERROR :
2369 (flags & DS_FLASH) ? COL_FLASH :
2370 (flags & DS_CLUE) ? COL_TRACK_CLUE : COL_TRACK;
2371 flags_best = best_bits(flags, flags_drag, &c);
2372 draw_tracks_specific(dr, ds, x, y, flags_best, c, COL_SLEEPER);
2374 /* Draw no-track marks, if present, in square and on edges. */
2376 flags_best = best_bits((flags & DS_NOTRACK) == DS_NOTRACK,
2377 (flags_drag & DS_NOTRACK) == DS_NOTRACK, &c);
2380 draw_line(dr, cx - off, cy - off, cx + off, cy + off, c);
2381 draw_line(dr, cx - off, cy + off, cx + off, cy - off, c);
2385 flags_best = best_bits(flags >> DS_NSHIFT, flags_drag >> DS_NSHIFT, &c);
2386 for (d = 1; d < 16; d *= 2) {
2391 if (flags_best & d) {
2392 cx += (d == R) ? t2 : (d == L) ? -t2 : 0;
2393 cy += (d == D) ? t2 : (d == U) ? -t2 : 0;
2395 draw_line(dr, cx - off, cy - off, cx + off, cy + off, c);
2396 draw_line(dr, cx - off, cy + off, cx + off, cy - off, c);
2401 draw_update(dr, ox, oy, TILE_SIZE, TILE_SIZE);
2404 static void draw_clue(drawing *dr, game_drawstate *ds, int w, int clue, int i, int col)
2406 int cx, cy, tsz = TILE_SIZE/2;
2410 cx = CENTERED_COORD(i);
2411 cy = CENTERED_COORD(-1);
2413 cx = CENTERED_COORD(w);
2414 cy = CENTERED_COORD(i-w);
2417 draw_rect(dr, cx - tsz + BORDER, cy - tsz + BORDER,
2418 TILE_SIZE - BORDER, TILE_SIZE - BORDER, COL_BACKGROUND);
2419 sprintf(buf, "%d", clue);
2420 draw_text(dr, cx, cy, FONT_VARIABLE, tsz, ALIGN_VCENTRE|ALIGN_HCENTRE,
2422 draw_update(dr, cx - tsz, cy - tsz, TILE_SIZE, TILE_SIZE);
2425 static void draw_loop_ends(drawing *dr, game_drawstate *ds,
2426 const game_state *state, int c)
2428 int tsz = TILE_SIZE/2;
2430 draw_text(dr, CENTERED_COORD(-1), CENTERED_COORD(state->numbers->row_s),
2431 FONT_VARIABLE, tsz, ALIGN_VCENTRE|ALIGN_HCENTRE,
2434 draw_text(dr, CENTERED_COORD(state->numbers->col_s), CENTERED_COORD(state->p.h),
2435 FONT_VARIABLE, tsz, ALIGN_VCENTRE|ALIGN_HCENTRE,
2439 static unsigned int s2d_flags(const game_state *state, int x, int y, const game_ui *ui)
2444 f = S_E_DIRS(state, x, y, E_TRACK);
2445 f |= (S_E_DIRS(state, x, y, E_NOTRACK) << DS_NSHIFT);
2447 if (state->sflags[y*w+x] & S_ERROR)
2449 if (state->sflags[y*w+x] & S_CLUE)
2451 if (state->sflags[y*w+x] & S_NOTRACK)
2453 if ((state->sflags[y*w+x] & S_TRACK) || (S_E_COUNT(state, x, y, E_TRACK) > 0))
2456 if (ui->cursor_active) {
2457 if (ui->curx >= x*2 && ui->curx <= (x+1)*2 &&
2458 ui->cury >= y*2 && ui->cury <= (y+1)*2) {
2460 if (ui->curx == x*2) f |= (L << DS_CSHIFT);
2461 if (ui->curx == (x+1)*2) f |= (R << DS_CSHIFT);
2462 if (ui->cury == y*2) f |= (U << DS_CSHIFT);
2463 if (ui->cury == (y+1)*2) f |= (D << DS_CSHIFT);
2470 static void game_redraw(drawing *dr, game_drawstate *ds, const game_state *oldstate,
2471 const game_state *state, int dir, const game_ui *ui,
2472 float animtime, float flashtime)
2474 int i, x, y, force = 0, flashing = 0, w = ds->w, h = ds->h;
2475 game_state *drag_state = NULL;
2479 * The initial contents of the window are not guaranteed and
2480 * can vary with front ends. To be on the safe side, all games
2481 * should start by drawing a big background-colour rectangle
2482 * covering the whole window.
2484 draw_rect(dr, 0, 0, (w+2)*TILE_SIZE + 2*BORDER, (h+2)*TILE_SIZE + 2*BORDER,
2487 draw_loop_ends(dr, ds, state, COL_CLUE);
2489 draw_line(dr, COORD(ds->w), COORD(0), COORD(ds->w), COORD(ds->h), COL_GRID);
2490 draw_line(dr, COORD(0), COORD(ds->h), COORD(ds->w), COORD(ds->h), COL_GRID);
2492 draw_update(dr, 0, 0, (w+2)*TILE_SIZE + 2*BORDER, (h+2)*TILE_SIZE + 2*BORDER);
2498 for (i = 0; i < w+h; i++) {
2499 if (force || (state->num_errors[i] != ds->num_errors[i])) {
2500 ds->num_errors[i] = state->num_errors[i];
2501 draw_clue(dr, ds, w, state->numbers->numbers[i], i,
2502 ds->num_errors[i] ? COL_ERROR : COL_CLUE);
2506 if (flashtime > 0 &&
2507 (flashtime <= FLASH_TIME/3 ||
2508 flashtime >= FLASH_TIME*2/3))
2509 flashing = DS_FLASH;
2512 drag_state = copy_and_apply_drag(state, ui);
2514 for (x = 0; x < w; x++) {
2515 for (y = 0; y < h; y++) {
2516 unsigned int f, f_d;
2518 f = s2d_flags(state, x, y, ui) | flashing;
2519 f_d = drag_state ? s2d_flags(drag_state, x, y, ui) : f;
2521 if (f != ds->flags[y*w+x] || f_d != ds->flags_drag[y*w+x] || force) {
2522 ds->flags[y*w+x] = f;
2523 ds->flags_drag[y*w+x] = f_d;
2524 draw_square(dr, ds, x, y, f, f_d);
2529 if (drag_state) free_game(drag_state);
2532 static float game_anim_length(const game_state *oldstate, const game_state *newstate,
2533 int dir, game_ui *ui)
2538 static float game_flash_length(const game_state *oldstate, const game_state *newstate,
2539 int dir, game_ui *ui)
2541 if (!oldstate->completed &&
2542 newstate->completed && !newstate->used_solve)
2548 static int game_status(const game_state *state)
2550 return state->completed ? +1 : 0;
2553 static int game_timing_state(const game_state *state, game_ui *ui)
2558 static void game_print_size(const game_params *params, float *x, float *y)
2562 /* The Times uses 7mm squares */
2563 game_compute_size(params, 700, &pw, &ph);
2568 static void game_print(drawing *dr, const game_state *state, int tilesize)
2570 int w = state->p.w, h = state->p.h;
2571 int black = print_mono_colour(dr, 0), grey = print_grey_colour(dr, 0.5F);
2574 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
2575 game_drawstate ads, *ds = &ads;
2576 game_set_size(dr, ds, NULL, tilesize);
2578 /* Grid, then border (second so it is on top) */
2579 print_line_width(dr, TILE_SIZE / 24);
2580 for (x = 1; x < w; x++)
2581 draw_line(dr, COORD(x), COORD(0), COORD(x), COORD(h), grey);
2582 for (y = 1; y < h; y++)
2583 draw_line(dr, COORD(0), COORD(y), COORD(w), COORD(y), grey);
2585 print_line_width(dr, TILE_SIZE / 16);
2586 draw_rect_outline(dr, COORD(0), COORD(0), w*TILE_SIZE, h*TILE_SIZE, black);
2588 print_line_width(dr, TILE_SIZE / 24);
2590 /* clue numbers, and loop ends */
2591 for (i = 0; i < w+h; i++)
2592 draw_clue(dr, ds, w, state->numbers->numbers[i], i, black);
2593 draw_loop_ends(dr, ds, state, black);
2595 /* clue tracks / solution */
2596 for (x = 0; x < w; x++) {
2597 for (y = 0; y < h; y++) {
2598 clip(dr, COORD(x), COORD(y), TILE_SIZE, TILE_SIZE);
2599 draw_tracks_specific(dr, ds, x, y, S_E_DIRS(state, x, y, E_TRACK),
2607 #define thegame tracks
2610 const struct game thegame = {
2611 "Train Tracks", "games.tracks", "tracks",
2618 TRUE, game_configure, custom_params,
2626 TRUE, game_can_format_as_text_now, game_text_format,
2634 PREFERRED_TILE_SIZE, game_compute_size, game_set_size,
2637 game_free_drawstate,
2642 TRUE, FALSE, game_print_size, game_print,
2643 FALSE, /* wants_statusbar */
2644 FALSE, game_timing_state,
2648 /* vim: set shiftwidth=4 tabstop=8: */