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 *loopclass,
1494 int ax, int ay, char dir,
1497 int w = state->p.w, ai = ay*w+ax, bx, by, bi, ac, bc;
1499 if (!(S_E_DIRS(state, ax, ay, E_TRACK) & dir)) return;
1503 if (!INGRID(state, bx, by)) return;
1506 ac = dsf_canonify(dsf, ai);
1507 bc = dsf_canonify(dsf, bi);
1513 dsf_merge(dsf, ai, bi);
1517 static int check_completion(game_state *state, int mark)
1519 int w = state->p.w, h = state->p.h, x, y, i, target, ret = TRUE;
1520 int ntrack, nnotrack;
1521 int *dsf, loopclass, pathclass;
1524 for (i = 0; i < w+h; i++) {
1525 state->num_errors[i] = 0;
1527 for (i = 0; i < w*h; i++) {
1528 state->sflags[i] &= ~S_ERROR;
1529 if (S_E_COUNT(state, i%w, i/w, E_TRACK) > 0) {
1530 if (S_E_COUNT(state, i%w, i/w, E_TRACK) > 2)
1531 state->sflags[i] |= S_ERROR;
1536 /* A cell is 'complete' if it has any edges marked as TRACK. */
1537 for (x = 0; x < w; x++) {
1538 target = state->numbers->numbers[x];
1539 ntrack = nnotrack = 0;
1540 for (y = 0; y < h; y++) {
1541 if (S_E_COUNT(state, x, y, E_TRACK) > 0 ||
1542 state->sflags[y*w+x] & S_TRACK)
1544 if (state->sflags[y*w+x] & S_NOTRACK)
1548 if (ntrack > target || nnotrack > (h-target)) {
1549 debug(("col %d error: target %d, track %d, notrack %d",
1550 x, target, ntrack, nnotrack));
1551 state->num_errors[x] = 1;
1554 if (ntrack != target)
1557 for (y = 0; y < h; y++) {
1558 target = state->numbers->numbers[w+y];
1559 ntrack = nnotrack = 0;
1560 for (x = 0; x < w; x++) {
1561 if (S_E_COUNT(state, x, y, E_TRACK) > 0 ||
1562 state->sflags[y*w+x] & S_TRACK)
1564 if (state->sflags[y*w+x] & S_NOTRACK)
1568 if (ntrack > target || nnotrack > (w-target)) {
1569 debug(("row %d error: target %d, track %d, notrack %d",
1570 y, target, ntrack, nnotrack));
1571 state->num_errors[w+y] = 1;
1574 if (ntrack != target)
1578 dsf = snewn(w*h, int);
1582 for (x = 0; x < w; x++) {
1583 for (y = 0; y < h; y++) {
1584 dsf_update_completion(state, &loopclass, x, y, R, dsf);
1585 dsf_update_completion(state, &loopclass, x, y, D, dsf);
1588 if (loopclass != -1) {
1589 debug(("loop detected, not complete"));
1590 ret = FALSE; /* no loop allowed */
1592 for (x = 0; x < w; x++) {
1593 for (y = 0; y < h; y++) {
1594 /* TODO this will only highlight the first loop found */
1595 if (dsf_canonify(dsf, y*w + x) == loopclass) {
1596 state->sflags[y*w+x] |= S_ERROR;
1603 pathclass = dsf_canonify(dsf, state->numbers->row_s*w);
1604 if (pathclass == dsf_canonify(dsf, (h-1)*w + state->numbers->col_s)) {
1605 /* We have a continuous path between the entrance and the exit: any
1606 other path must be in error. */
1607 for (i = 0; i < w*h; i++) {
1608 if ((dsf_canonify(dsf, i) != pathclass) &&
1609 ((state->sflags[i] & S_TRACK) ||
1610 (S_E_COUNT(state, i%w, i/w, E_TRACK) > 0)))
1611 state->sflags[i] |= S_ERROR;
1617 state->completed = ret;
1622 /* Code borrowed from Pearl. */
1625 int dragging, clearing, notrack;
1626 int drag_sx, drag_sy, drag_ex, drag_ey; /* drag start and end grid coords */
1627 int clickx, clicky; /* pixel position of initial click */
1629 int curx, cury; /* grid position of keyboard cursor; uses half-size grid */
1630 int cursor_active; /* TRUE iff cursor is shown */
1633 static game_ui *new_ui(const game_state *state)
1635 game_ui *ui = snew(game_ui);
1637 ui->clearing = ui->notrack = ui->dragging = 0;
1638 ui->drag_sx = ui->drag_sy = ui->drag_ex = ui->drag_ey = -1;
1639 ui->cursor_active = FALSE;
1640 ui->curx = ui->cury = 1;
1645 static void free_ui(game_ui *ui)
1650 static char *encode_ui(const game_ui *ui)
1655 static void decode_ui(game_ui *ui, const char *encoding)
1659 static void game_changed_state(game_ui *ui, const game_state *oldstate,
1660 const game_state *newstate)
1664 #define PREFERRED_TILE_SIZE 30
1665 #define HALFSZ (ds->sz6*3)
1666 #define THIRDSZ (ds->sz6*2)
1667 #define TILE_SIZE (ds->sz6*6)
1669 #define BORDER (TILE_SIZE/8)
1670 #define BORDER_WIDTH (max(TILE_SIZE / 32, 1))
1672 #define COORD(x) ( (x+1) * TILE_SIZE + BORDER )
1673 #define CENTERED_COORD(x) ( COORD(x) + TILE_SIZE/2 )
1674 #define FROMCOORD(x) ( ((x) < BORDER) ? -1 : ( ((x) - BORDER) / TILE_SIZE) - 1 )
1676 #define DS_DSHIFT 4 /* R/U/L/D shift, for drag-in-progress flags */
1678 #define DS_ERROR (1 << 8)
1679 #define DS_CLUE (1 << 9)
1680 #define DS_NOTRACK (1 << 10)
1681 #define DS_FLASH (1 << 11)
1682 #define DS_CURSOR (1 << 12) /* cursor in square (centre, or on edge) */
1683 #define DS_TRACK (1 << 13)
1684 #define DS_CLEARING (1 << 14)
1686 #define DS_NSHIFT 16 /* R/U/L/D shift, for no-track edge flags */
1687 #define DS_CSHIFT 20 /* R/U/L/D shift, for cursor-on-edge */
1689 struct game_drawstate {
1694 unsigned int *flags, *flags_drag;
1698 static void update_ui_drag(const game_state *state, game_ui *ui, int gx, int gy)
1700 int w = state->p.w, h = state->p.h;
1701 int dx = abs(ui->drag_sx - gx), dy = abs(ui->drag_sy - gy);
1704 ui->drag_ex = gx < 0 ? 0 : gx >= w ? w-1 : gx;
1705 ui->drag_ey = ui->drag_sy;
1706 ui->dragging = TRUE;
1707 } else if (dx == 0) {
1708 ui->drag_ex = ui->drag_sx;
1709 ui->drag_ey = gy < 0 ? 0 : gy >= h ? h-1 : gy;
1710 ui->dragging = TRUE;
1712 ui->drag_ex = ui->drag_sx;
1713 ui->drag_ey = ui->drag_sy;
1714 ui->dragging = FALSE;
1718 static int ui_can_flip_edge(const game_state *state, int x, int y, int dir,
1721 int w = state->p.w /*, h = state->shared->h, sz = state->shared->sz */;
1722 int x2 = x + DX(dir);
1723 int y2 = y + DY(dir);
1724 unsigned int sf1, sf2, ef;
1726 if (!INGRID(state, x, y) || !INGRID(state, x2, y2))
1729 sf1 = state->sflags[y*w + x];
1730 sf2 = state->sflags[y2*w + x2];
1731 if ( !notrack && ((sf1 & S_CLUE) || (sf2 & S_CLUE)) )
1734 ef = S_E_FLAGS(state, x, y, dir);
1736 /* if we're going to _set_ NOTRACK (i.e. the flag is currently unset),
1737 make sure the edge is not already set to TRACK. The adjacent squares
1738 could be set to TRACK, because we don't know which edges the general
1739 square setting refers to. */
1740 if (!(ef & E_NOTRACK) && (ef & E_TRACK))
1743 if (!(ef & E_TRACK)) {
1744 /* if we're going to _set_ TRACK, make sure neither adjacent square nor
1745 the edge itself is already set to NOTRACK. */
1746 if ((sf1 & S_NOTRACK) || (sf2 & S_NOTRACK) || (ef & E_NOTRACK))
1748 /* if we're going to _set_ TRACK, make sure neither adjacent square has
1749 2 track flags already. */
1750 if ((S_E_COUNT(state, x, y, E_TRACK) >= 2) ||
1751 (S_E_COUNT(state, x2, y2, E_TRACK) >= 2))
1758 static int ui_can_flip_square(const game_state *state, int x, int y, int notrack)
1760 int w = state->p.w, trackc;
1763 if (!INGRID(state, x, y)) return FALSE;
1764 sf = state->sflags[y*w+x];
1765 trackc = S_E_COUNT(state, x, y, E_TRACK);
1767 if (sf & S_CLUE) return FALSE;
1770 /* If we're setting S_NOTRACK, we cannot have either S_TRACK or any E_TRACK. */
1771 if (!(sf & S_NOTRACK) && ((sf & S_TRACK) || (trackc > 0)))
1774 /* If we're setting S_TRACK, we cannot have any S_NOTRACK (we could have
1775 E_NOTRACK, though, because one or two wouldn't rule out a track) */
1776 if (!(sf & S_TRACK) && (sf & S_NOTRACK))
1782 static char *edge_flip_str(const game_state *state, int x, int y, int dir, int notrack, char *buf) {
1783 unsigned ef = S_E_FLAGS(state, x, y, dir);
1787 c = (ef & E_NOTRACK) ? 'n' : 'N';
1789 c = (ef & E_TRACK) ? 't' : 'T';
1791 sprintf(buf, "%c%c%d,%d", c, MOVECHAR(dir), x, y);
1795 static char *square_flip_str(const game_state *state, int x, int y, int notrack, char *buf) {
1796 unsigned f = state->sflags[y*state->p.w+x];
1800 c = (f & E_NOTRACK) ? 'n' : 'N';
1802 c = (f & E_TRACK) ? 't' : 'T';
1804 sprintf(buf, "%cS%d,%d", c, x, y);
1808 #define SIGN(x) ((x<0) ? -1 : (x>0))
1810 static game_state *copy_and_apply_drag(const game_state *state, const game_ui *ui)
1812 game_state *after = dup_game(state);
1813 int x1, y1, x2, y2, x, y, w = state->p.w;
1814 unsigned f = ui->notrack ? S_NOTRACK : S_TRACK, ff;
1816 x1 = min(ui->drag_sx, ui->drag_ex); x2 = max(ui->drag_sx, ui->drag_ex);
1817 y1 = min(ui->drag_sy, ui->drag_ey); y2 = max(ui->drag_sy, ui->drag_ey);
1819 /* actually either x1 == x2, or y1 == y2, but it's easier just to code
1821 for (x = x1; x <= x2; x++) {
1822 for (y = y1; y <= y2; y++) {
1823 ff = state->sflags[y*w+x];
1824 if (ui->clearing && !(ff & f))
1825 continue; /* nothing to do, clearing and already clear */
1826 else if (!ui->clearing && (ff & f))
1827 continue; /* nothing to do, setting and already set */
1828 else if (ui_can_flip_square(state, x, y, ui->notrack))
1829 after->sflags[y*w+x] ^= f;
1835 #define KEY_DIRECTION(btn) (\
1836 (btn) == CURSOR_DOWN ? D : (btn) == CURSOR_UP ? U :\
1837 (btn) == CURSOR_LEFT ? L : R)
1839 static char *interpret_move(const game_state *state, game_ui *ui,
1840 const game_drawstate *ds,
1841 int x, int y, int button)
1843 int w = state->p.w, h = state->p.h, direction;
1844 int gx = FROMCOORD(x), gy = FROMCOORD(y);
1847 /* --- mouse operations --- */
1849 if (IS_MOUSE_DOWN(button)) {
1850 ui->cursor_active = FALSE;
1851 ui->dragging = FALSE;
1853 if (!INGRID(state, gx, gy)) {
1854 /* can't drag from off grid */
1858 if (button == RIGHT_BUTTON) {
1860 ui->clearing = state->sflags[gy*w+gx] & S_NOTRACK;
1862 ui->notrack = FALSE;
1863 ui->clearing = state->sflags[gy*w+gx] & S_TRACK;
1868 ui->drag_sx = ui->drag_ex = gx;
1869 ui->drag_sy = ui->drag_ey = gy;
1874 if (IS_MOUSE_DRAG(button)) {
1875 ui->cursor_active = FALSE;
1876 update_ui_drag(state, ui, gx, gy);
1880 if (IS_MOUSE_RELEASE(button)) {
1881 ui->cursor_active = FALSE;
1883 (ui->drag_sx != ui->drag_ex || ui->drag_sy != ui->drag_ey)) {
1884 game_state *dragged = copy_and_apply_drag(state, ui);
1885 char *ret = move_string_diff(state, dragged, FALSE);
1894 /* We might still have been dragging (and just done a one-
1895 * square drag): cancel drag, so undo doesn't make it like
1896 * a drag-in-progress. */
1899 /* Click (or tiny drag). Work out which edge we were
1903 * We process clicks based on the mouse-down location,
1904 * because that's more natural for a user to carefully
1905 * control than the mouse-up.
1910 cx = CENTERED_COORD(gx);
1911 cy = CENTERED_COORD(gy);
1913 if (!INGRID(state, gx, gy) || FROMCOORD(x) != gx || FROMCOORD(y) != gy)
1916 if (max(abs(x-cx),abs(y-cy)) < TILE_SIZE/4) {
1917 if (ui_can_flip_square(state, gx, gy, button == RIGHT_RELEASE))
1918 return square_flip_str(state, gx, gy, button == RIGHT_RELEASE, tmpbuf);
1921 if (abs(x-cx) < abs(y-cy)) {
1922 /* Closest to top/bottom edge. */
1923 direction = (y < cy) ? U : D;
1925 /* Closest to left/right edge. */
1926 direction = (x < cx) ? L : R;
1928 if (ui_can_flip_edge(state, gx, gy, direction,
1929 button == RIGHT_RELEASE))
1930 return edge_flip_str(state, gx, gy, direction,
1931 button == RIGHT_RELEASE, tmpbuf);
1938 /* --- cursor/keyboard operations --- */
1940 if (IS_CURSOR_MOVE(button)) {
1941 int dx = (button == CURSOR_LEFT) ? -1 : ((button == CURSOR_RIGHT) ? +1 : 0);
1942 int dy = (button == CURSOR_DOWN) ? +1 : ((button == CURSOR_UP) ? -1 : 0);
1944 if (!ui->cursor_active) {
1945 ui->cursor_active = TRUE;
1949 ui->curx = ui->curx + dx;
1950 ui->cury = ui->cury + dy;
1951 if ((ui->curx % 2 == 0) && (ui->cury % 2 == 0)) {
1952 /* disallow cursor on square corners: centres and edges only */
1953 ui->curx += dx; ui->cury += dy;
1955 ui->curx = min(max(ui->curx, 1), 2*w-1);
1956 ui->cury = min(max(ui->cury, 1), 2*h-1);
1960 if (IS_CURSOR_SELECT(button)) {
1961 if (!ui->cursor_active) {
1962 ui->cursor_active = TRUE;
1965 /* click on square corner does nothing (shouldn't get here) */
1966 if ((ui->curx % 2) == 0 && (ui->cury % 2 == 0))
1971 direction = ((ui->curx % 2) == 0) ? L : ((ui->cury % 2) == 0) ? U : 0;
1974 ui_can_flip_edge(state, gx, gy, direction, button == CURSOR_SELECT2))
1975 return edge_flip_str(state, gx, gy, direction, button == CURSOR_SELECT2, tmpbuf);
1976 else if (!direction &&
1977 ui_can_flip_square(state, gx, gy, button == CURSOR_SELECT2))
1978 return square_flip_str(state, gx, gy, button == CURSOR_SELECT2, tmpbuf);
1983 /* helps to debug the solver */
1984 if (button == 'H' || button == 'h')
1991 static game_state *execute_move(const game_state *state, const char *move)
1993 int w = state->p.w, x, y, n, i;
1996 game_state *ret = dup_game(state);
1998 /* this is breaking the bank on GTK, which vsprintf's into a fixed-size buffer
1999 * which is 4096 bytes long. vsnprintf needs a feature-test macro to use, faff. */
2000 /*debug(("move: %s\n", move));*/
2005 ret->used_solve = TRUE;
2007 } else if (c == 'T' || c == 't' || c == 'N' || c == 'n') {
2008 /* set track, clear track; set notrack, clear notrack */
2010 if (sscanf(move, "%c%d,%d%n", &d, &x, &y, &n) != 3)
2012 if (!INGRID(state, x, y)) goto badmove;
2014 f = (c == 'T' || c == 't') ? S_TRACK : S_NOTRACK;
2017 if (c == 'T' || c == 'N')
2018 ret->sflags[y*w+x] |= f;
2020 ret->sflags[y*w+x] &= ~f;
2021 } else if (d == 'U' || d == 'D' || d == 'L' || d == 'R') {
2022 for (i = 0; i < 4; i++) {
2025 if (MOVECHAR(df) == d) {
2026 if (c == 'T' || c == 'N')
2027 S_E_SET(ret, x, y, df, f);
2029 S_E_CLEAR(ret, x, y, df, f);
2035 } else if (c == 'H') {
2036 tracks_solve(ret, DIFFCOUNT);
2047 check_completion(ret, TRUE);
2056 /* ----------------------------------------------------------------------
2060 #define FLASH_TIME 0.5F
2062 static void game_compute_size(const game_params *params, int tilesize,
2065 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
2069 ads.sz6 = tilesize/6;
2071 *x = (params->w+2) * TILE_SIZE + 2 * BORDER;
2072 *y = (params->h+2) * TILE_SIZE + 2 * BORDER;
2075 static void game_set_size(drawing *dr, game_drawstate *ds,
2076 const game_params *params, int tilesize)
2078 ds->sz6 = tilesize/6;
2082 COL_BACKGROUND, COL_LOWLIGHT, COL_HIGHLIGHT,
2083 COL_TRACK_BACKGROUND = COL_LOWLIGHT,
2084 COL_GRID, COL_CLUE, COL_CURSOR,
2085 COL_TRACK, COL_TRACK_CLUE, COL_SLEEPER,
2086 COL_DRAGON, COL_DRAGOFF,
2087 COL_ERROR, COL_FLASH,
2091 static float *game_colours(frontend *fe, int *ncolours)
2093 float *ret = snewn(3 * NCOLOURS, float);
2096 game_mkhighlight(fe, ret, COL_BACKGROUND, COL_HIGHLIGHT, COL_LOWLIGHT);
2098 for (i = 0; i < 3; i++) {
2099 ret[COL_TRACK_CLUE * 3 + i] = 0.0F;
2100 ret[COL_TRACK * 3 + i] = 0.5F;
2101 ret[COL_CLUE * 3 + i] = 0.0F;
2102 ret[COL_GRID * 3 + i] = 0.75F;
2103 ret[COL_CURSOR * 3 + i] = 0.6F;
2106 ret[COL_SLEEPER * 3 + 0] = 0.5F;
2107 ret[COL_SLEEPER * 3 + 1] = 0.4F;
2108 ret[COL_SLEEPER * 3 + 2] = 0.1F;
2110 ret[COL_ERROR * 3 + 0] = 1.0F;
2111 ret[COL_ERROR * 3 + 1] = 0.0F;
2112 ret[COL_ERROR * 3 + 2] = 0.0F;
2114 ret[COL_DRAGON * 3 + 0] = 0.0F;
2115 ret[COL_DRAGON * 3 + 1] = 0.0F;
2116 ret[COL_DRAGON * 3 + 2] = 1.0F;
2118 ret[COL_DRAGOFF * 3 + 0] = 0.8F;
2119 ret[COL_DRAGOFF * 3 + 1] = 0.8F;
2120 ret[COL_DRAGOFF * 3 + 2] = 1.0F;
2122 ret[COL_FLASH * 3 + 0] = 1.0F;
2123 ret[COL_FLASH * 3 + 1] = 1.0F;
2124 ret[COL_FLASH * 3 + 2] = 1.0F;
2126 *ncolours = NCOLOURS;
2130 static game_drawstate *game_new_drawstate(drawing *dr, const game_state *state)
2132 struct game_drawstate *ds = snew(struct game_drawstate);
2136 ds->started = FALSE;
2140 ds->sz = ds->w*ds->h;
2141 ds->flags = snewn(ds->sz, unsigned int);
2142 ds->flags_drag = snewn(ds->sz, unsigned int);
2143 for (i = 0; i < ds->sz; i++)
2144 ds->flags[i] = ds->flags_drag[i] = 0;
2146 ds->num_errors = snewn(ds->w+ds->h, int);
2147 for (i = 0; i < ds->w+ds->h; i++)
2148 ds->num_errors[i] = 0;
2153 static void game_free_drawstate(drawing *dr, game_drawstate *ds)
2156 sfree(ds->flags_drag);
2157 sfree(ds->num_errors);
2161 static void draw_circle_sleepers(drawing *dr, game_drawstate *ds,
2162 float cx, float cy, float r2, float thickness, int c)
2164 float qr6 = (float)PI/12, qr3 = (float)PI/6, th, x1, y1, x2, y2;
2165 float t6 = THIRDSZ/2.0F, r1 = t6;
2168 for (i = 0; i < 12; i++) {
2170 x1 = r1*(float)cos(th);
2171 x2 = r2*(float)cos(th);
2172 y1 = r1*(float)sin(th);
2173 y2 = r2*(float)sin(th);
2174 draw_thick_line(dr, thickness, cx+x1, cy+y1, cx+x2, cy+y2, c);
2178 static void draw_thick_circle_outline(drawing *dr, float thickness,
2179 float cx, float cy, float r,
2182 float circ4 = 0.5F * (float)PI * r, ang, x1, y1, x2, y2;
2185 nseg = (int)(circ4 / 4.0F)*4; /* ensure a quarter-circle has a whole #segs */
2186 ang = 2.0F*(float)PI / nseg;
2188 for (i = 0; i < nseg; i++) {
2189 float th = ang * i, th2 = ang * (i+1);
2190 x1 = cx + r*(float)cos(th);
2191 x2 = cx + r*(float)cos(th2);
2192 y1 = cy + r*(float)sin(th);
2193 y2 = cy + r*(float)sin(th2);
2194 debug(("circ outline: x=%.2f -> %.2f, thick=%.2f", x1, x2, thickness));
2195 draw_thick_line(dr, thickness, x1, y1, x2, y2, colour);
2199 static void draw_tracks_specific(drawing *dr, game_drawstate *ds,
2200 int x, int y, unsigned int flags,
2201 int ctrack, int csleeper)
2203 float ox = (float)COORD(x), oy = (float)COORD(y), cx, cy;
2204 float t1 = (float)TILE_SIZE, t3 = TILE_SIZE/3.0F, t6 = TILE_SIZE/6.0F;
2206 float thick_track = TILE_SIZE/8.0F, thick_sleeper = TILE_SIZE/12.0F;
2209 for (i = 1; i <= 7; i+=2) {
2210 cx = ox + TILE_SIZE/8.0F*i;
2211 draw_thick_line(dr, thick_sleeper,
2212 cx, oy+t6, cx, oy+t6+2*t3, csleeper);
2214 draw_thick_line(dr, thick_track, ox, oy + t3, ox + TILE_SIZE, oy + t3, ctrack);
2215 draw_thick_line(dr, thick_track, ox, oy + 2*t3, ox + TILE_SIZE, oy + 2*t3, ctrack);
2219 for (i = 1; i <= 7; i+=2) {
2220 cy = oy + TILE_SIZE/8.0F*i;
2221 draw_thick_line(dr, thick_sleeper,
2222 ox+t6, cy, ox+t6+2*t3, cy, csleeper);
2224 debug(("vert line: x=%.2f, thick=%.2f", ox + t3, thick_track));
2225 draw_thick_line(dr, thick_track, ox + t3, oy, ox + t3, oy + TILE_SIZE, ctrack);
2226 draw_thick_line(dr, thick_track, ox + 2*t3, oy, ox + 2*t3, oy + TILE_SIZE, ctrack);
2229 if (flags == UL || flags == DL || flags == UR || flags == DR) {
2230 cx = (flags & L) ? ox : ox + TILE_SIZE;
2231 cy = (flags & U) ? oy : oy + TILE_SIZE;
2233 draw_circle_sleepers(dr, ds, cx, cy, (float)(5*t6), thick_sleeper, csleeper);
2235 draw_thick_circle_outline(dr, thick_track, (float)cx, (float)cy,
2237 draw_thick_circle_outline(dr, thick_track, (float)cx, (float)cy,
2243 for (d = 1; d < 16; d *= 2) {
2244 float ox1 = 0, ox2 = 0, oy1 = 0, oy2 = 0;
2246 if (!(flags & d)) continue;
2248 for (i = 1; i <= 2; i++) {
2253 } else if (d == R) {
2255 ox2 = t1 - thick_track;
2257 } else if (d == U) {
2261 } else if (d == D) {
2264 oy2 = t1 - thick_track;
2266 draw_thick_line(dr, thick_track, ox+ox1, oy+oy1, ox+ox2, oy+oy2, ctrack);
2271 static unsigned int best_bits(unsigned int flags, unsigned int flags_drag, int *col)
2273 int nb_orig = nbits[flags & ALLDIR], nb_drag = nbits[flags_drag & ALLDIR];
2275 if (nb_orig > nb_drag) {
2277 return flags & ALLDIR;
2278 } else if (nb_orig < nb_drag) {
2280 return flags_drag & ALLDIR;
2282 return flags & ALLDIR; /* same number of bits: no special colour. */
2285 static void draw_square(drawing *dr, game_drawstate *ds,
2286 int x, int y, unsigned int flags, unsigned int flags_drag)
2288 int t2 = HALFSZ, t16 = HALFSZ/4, off;
2289 int ox = COORD(x), oy = COORD(y), cx = ox + t2, cy = oy + t2, d, c;
2290 int bg = (flags & DS_TRACK) ? COL_TRACK_BACKGROUND : COL_BACKGROUND;
2291 unsigned int flags_best;
2295 /* Clip to the grid square. */
2296 clip(dr, ox, oy, TILE_SIZE, TILE_SIZE);
2298 /* Clear the square. */
2299 best_bits((flags & DS_TRACK) == DS_TRACK,
2300 (flags_drag & DS_TRACK) == DS_TRACK, &bg);
2301 draw_rect(dr, ox, oy, TILE_SIZE, TILE_SIZE, bg);
2303 /* Draw outline of grid square */
2304 draw_line(dr, ox, oy, COORD(x+1), oy, COL_GRID);
2305 draw_line(dr, ox, oy, ox, COORD(y+1), COL_GRID);
2307 /* More outlines for clue squares. */
2308 if (flags & DS_CURSOR) {
2309 int curx, cury, curw, curh;
2312 curx = ox + off; cury = oy + off;
2313 curw = curh = TILE_SIZE - (2*off) + 1;
2315 if (flags & (U << DS_CSHIFT)) {
2316 cury = oy - off; curh = 2*off + 1;
2317 } else if (flags & (D << DS_CSHIFT)) {
2318 cury = oy + TILE_SIZE - off; curh = 2*off + 1;
2319 } else if (flags & (L << DS_CSHIFT)) {
2320 curx = ox - off; curw = 2*off + 1;
2321 } else if (flags & (R << DS_CSHIFT)) {
2322 curx = ox + TILE_SIZE - off; curw = 2*off + 1;
2325 draw_rect_outline(dr, curx, cury, curw, curh, COL_GRID);
2328 /* Draw tracks themselves */
2329 c = (flags & DS_ERROR) ? COL_ERROR :
2330 (flags & DS_FLASH) ? COL_FLASH :
2331 (flags & DS_CLUE) ? COL_TRACK_CLUE : COL_TRACK;
2332 flags_best = best_bits(flags, flags_drag, &c);
2333 draw_tracks_specific(dr, ds, x, y, flags_best, c, COL_SLEEPER);
2335 /* Draw no-track marks, if present, in square and on edges. */
2337 flags_best = best_bits((flags & DS_NOTRACK) == DS_NOTRACK,
2338 (flags_drag & DS_NOTRACK) == DS_NOTRACK, &c);
2341 draw_line(dr, cx - off, cy - off, cx + off, cy + off, c);
2342 draw_line(dr, cx - off, cy + off, cx + off, cy - off, c);
2346 flags_best = best_bits(flags >> DS_NSHIFT, flags_drag >> DS_NSHIFT, &c);
2347 for (d = 1; d < 16; d *= 2) {
2352 if (flags_best & d) {
2353 cx += (d == R) ? t2 : (d == L) ? -t2 : 0;
2354 cy += (d == D) ? t2 : (d == U) ? -t2 : 0;
2356 draw_line(dr, cx - off, cy - off, cx + off, cy + off, c);
2357 draw_line(dr, cx - off, cy + off, cx + off, cy - off, c);
2362 draw_update(dr, ox, oy, TILE_SIZE, TILE_SIZE);
2365 static void draw_clue(drawing *dr, game_drawstate *ds, int w, int clue, int i, int col)
2367 int cx, cy, tsz = TILE_SIZE/2;
2371 cx = CENTERED_COORD(i);
2372 cy = CENTERED_COORD(-1);
2374 cx = CENTERED_COORD(w);
2375 cy = CENTERED_COORD(i-w);
2378 draw_rect(dr, cx - tsz + BORDER, cy - tsz + BORDER,
2379 TILE_SIZE - BORDER, TILE_SIZE - BORDER, COL_BACKGROUND);
2380 sprintf(buf, "%d", clue);
2381 draw_text(dr, cx, cy, FONT_VARIABLE, tsz, ALIGN_VCENTRE|ALIGN_HCENTRE,
2383 draw_update(dr, cx - tsz, cy - tsz, TILE_SIZE, TILE_SIZE);
2386 static void draw_loop_ends(drawing *dr, game_drawstate *ds,
2387 const game_state *state, int c)
2389 int tsz = TILE_SIZE/2;
2391 draw_text(dr, CENTERED_COORD(-1), CENTERED_COORD(state->numbers->row_s),
2392 FONT_VARIABLE, tsz, ALIGN_VCENTRE|ALIGN_HCENTRE,
2395 draw_text(dr, CENTERED_COORD(state->numbers->col_s), CENTERED_COORD(state->p.h),
2396 FONT_VARIABLE, tsz, ALIGN_VCENTRE|ALIGN_HCENTRE,
2400 static unsigned int s2d_flags(const game_state *state, int x, int y, const game_ui *ui)
2405 f = S_E_DIRS(state, x, y, E_TRACK);
2406 f |= (S_E_DIRS(state, x, y, E_NOTRACK) << DS_NSHIFT);
2408 if (state->sflags[y*w+x] & S_ERROR)
2410 if (state->sflags[y*w+x] & S_CLUE)
2412 if (state->sflags[y*w+x] & S_NOTRACK)
2414 if ((state->sflags[y*w+x] & S_TRACK) || (S_E_COUNT(state, x, y, E_TRACK) > 0))
2417 if (ui->cursor_active) {
2418 if (ui->curx >= x*2 && ui->curx <= (x+1)*2 &&
2419 ui->cury >= y*2 && ui->cury <= (y+1)*2) {
2421 if (ui->curx == x*2) f |= (L << DS_CSHIFT);
2422 if (ui->curx == (x+1)*2) f |= (R << DS_CSHIFT);
2423 if (ui->cury == y*2) f |= (U << DS_CSHIFT);
2424 if (ui->cury == (y+1)*2) f |= (D << DS_CSHIFT);
2431 static void game_redraw(drawing *dr, game_drawstate *ds, const game_state *oldstate,
2432 const game_state *state, int dir, const game_ui *ui,
2433 float animtime, float flashtime)
2435 int i, x, y, force = 0, flashing = 0, w = ds->w, h = ds->h;
2436 game_state *drag_state = NULL;
2440 * The initial contents of the window are not guaranteed and
2441 * can vary with front ends. To be on the safe side, all games
2442 * should start by drawing a big background-colour rectangle
2443 * covering the whole window.
2445 draw_rect(dr, 0, 0, (w+2)*TILE_SIZE + 2*BORDER, (h+2)*TILE_SIZE + 2*BORDER,
2448 draw_loop_ends(dr, ds, state, COL_CLUE);
2450 draw_line(dr, COORD(ds->w), COORD(0), COORD(ds->w), COORD(ds->h), COL_GRID);
2451 draw_line(dr, COORD(0), COORD(ds->h), COORD(ds->w), COORD(ds->h), COL_GRID);
2453 draw_update(dr, 0, 0, (w+2)*TILE_SIZE + 2*BORDER, (h+2)*TILE_SIZE + 2*BORDER);
2459 for (i = 0; i < w+h; i++) {
2460 if (force || (state->num_errors[i] != ds->num_errors[i])) {
2461 ds->num_errors[i] = state->num_errors[i];
2462 draw_clue(dr, ds, w, state->numbers->numbers[i], i,
2463 ds->num_errors[i] ? COL_ERROR : COL_CLUE);
2467 if (flashtime > 0 &&
2468 (flashtime <= FLASH_TIME/3 ||
2469 flashtime >= FLASH_TIME*2/3))
2470 flashing = DS_FLASH;
2473 drag_state = copy_and_apply_drag(state, ui);
2475 for (x = 0; x < w; x++) {
2476 for (y = 0; y < h; y++) {
2477 unsigned int f, f_d;
2479 f = s2d_flags(state, x, y, ui) | flashing;
2480 f_d = drag_state ? s2d_flags(drag_state, x, y, ui) : f;
2482 if (f != ds->flags[y*w+x] || f_d != ds->flags_drag[y*w+x] || force) {
2483 ds->flags[y*w+x] = f;
2484 ds->flags_drag[y*w+x] = f_d;
2485 draw_square(dr, ds, x, y, f, f_d);
2490 if (drag_state) free_game(drag_state);
2493 static float game_anim_length(const game_state *oldstate, const game_state *newstate,
2494 int dir, game_ui *ui)
2499 static float game_flash_length(const game_state *oldstate, const game_state *newstate,
2500 int dir, game_ui *ui)
2502 if (!oldstate->completed &&
2503 newstate->completed && !newstate->used_solve)
2509 static int game_status(const game_state *state)
2511 return state->completed ? +1 : 0;
2514 static int game_timing_state(const game_state *state, game_ui *ui)
2519 static void game_print_size(const game_params *params, float *x, float *y)
2523 /* The Times uses 7mm squares */
2524 game_compute_size(params, 700, &pw, &ph);
2529 static void game_print(drawing *dr, const game_state *state, int tilesize)
2531 int w = state->p.w, h = state->p.h;
2532 int black = print_mono_colour(dr, 0), grey = print_grey_colour(dr, 0.5F);
2535 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
2536 game_drawstate ads, *ds = &ads;
2537 game_set_size(dr, ds, NULL, tilesize);
2539 /* Grid, then border (second so it is on top) */
2540 print_line_width(dr, TILE_SIZE / 24);
2541 for (x = 1; x < w; x++)
2542 draw_line(dr, COORD(x), COORD(0), COORD(x), COORD(h), grey);
2543 for (y = 1; y < h; y++)
2544 draw_line(dr, COORD(0), COORD(y), COORD(w), COORD(y), grey);
2546 print_line_width(dr, TILE_SIZE / 16);
2547 draw_rect_outline(dr, COORD(0), COORD(0), w*TILE_SIZE, h*TILE_SIZE, black);
2549 print_line_width(dr, TILE_SIZE / 24);
2551 /* clue numbers, and loop ends */
2552 for (i = 0; i < w+h; i++)
2553 draw_clue(dr, ds, w, state->numbers->numbers[i], i, black);
2554 draw_loop_ends(dr, ds, state, black);
2556 /* clue tracks / solution */
2557 for (x = 0; x < w; x++) {
2558 for (y = 0; y < h; y++) {
2559 clip(dr, COORD(x), COORD(y), TILE_SIZE, TILE_SIZE);
2560 draw_tracks_specific(dr, ds, x, y, S_E_DIRS(state, x, y, E_TRACK),
2568 #define thegame tracks
2571 const struct game thegame = {
2572 "Train Tracks", "games.tracks", "tracks",
2579 TRUE, game_configure, custom_params,
2587 TRUE, game_can_format_as_text_now, game_text_format,
2595 PREFERRED_TILE_SIZE, game_compute_size, game_set_size,
2598 game_free_drawstate,
2603 TRUE, FALSE, game_print_size, game_print,
2604 FALSE, /* wants_statusbar */
2605 FALSE, game_timing_state,
2609 /* vim: set shiftwidth=4 tabstop=8: */