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)
1543 if (state->sflags[y*w+x] & S_NOTRACK)
1547 if (ntrack > target || nnotrack > (h-target)) {
1548 debug(("col %d error: target %d, track %d, notrack %d",
1549 x, target, ntrack, nnotrack));
1550 state->num_errors[x] = 1;
1553 if (ntrack != target)
1556 for (y = 0; y < h; y++) {
1557 target = state->numbers->numbers[w+y];
1558 ntrack = nnotrack = 0;
1559 for (x = 0; x < w; x++) {
1560 if (S_E_COUNT(state, x, y, E_TRACK) == 2)
1562 if (state->sflags[y*w+x] & S_NOTRACK)
1566 if (ntrack > target || nnotrack > (w-target)) {
1567 debug(("row %d error: target %d, track %d, notrack %d",
1568 y, target, ntrack, nnotrack));
1569 state->num_errors[w+y] = 1;
1572 if (ntrack != target)
1576 dsf = snewn(w*h, int);
1580 for (x = 0; x < w; x++) {
1581 for (y = 0; y < h; y++) {
1582 dsf_update_completion(state, &loopclass, x, y, R, dsf);
1583 dsf_update_completion(state, &loopclass, x, y, D, dsf);
1586 if (loopclass != -1) {
1587 debug(("loop detected, not complete"));
1588 ret = FALSE; /* no loop allowed */
1590 for (x = 0; x < w; x++) {
1591 for (y = 0; y < h; y++) {
1592 /* TODO this will only highlight the first loop found */
1593 if (dsf_canonify(dsf, y*w + x) == loopclass) {
1594 state->sflags[y*w+x] |= S_ERROR;
1601 pathclass = dsf_canonify(dsf, state->numbers->row_s*w);
1602 if (pathclass == dsf_canonify(dsf, (h-1)*w + state->numbers->col_s)) {
1603 /* We have a continuous path between the entrance and the exit: any
1604 other path must be in error. */
1605 for (i = 0; i < w*h; i++) {
1606 if ((dsf_canonify(dsf, i) != pathclass) &&
1607 ((state->sflags[i] & S_TRACK) ||
1608 (S_E_COUNT(state, i%w, i/w, E_TRACK) > 0)))
1609 state->sflags[i] |= S_ERROR;
1615 state->completed = ret;
1620 /* Code borrowed from Pearl. */
1623 int dragging, clearing, notrack;
1624 int drag_sx, drag_sy, drag_ex, drag_ey; /* drag start and end grid coords */
1625 int clickx, clicky; /* pixel position of initial click */
1627 int curx, cury; /* grid position of keyboard cursor; uses half-size grid */
1628 int cursor_active; /* TRUE iff cursor is shown */
1631 static game_ui *new_ui(const game_state *state)
1633 game_ui *ui = snew(game_ui);
1635 ui->clearing = ui->notrack = ui->dragging = 0;
1636 ui->drag_sx = ui->drag_sy = ui->drag_ex = ui->drag_ey = -1;
1637 ui->cursor_active = FALSE;
1638 ui->curx = ui->cury = 1;
1643 static void free_ui(game_ui *ui)
1648 static char *encode_ui(const game_ui *ui)
1653 static void decode_ui(game_ui *ui, const char *encoding)
1657 static void game_changed_state(game_ui *ui, const game_state *oldstate,
1658 const game_state *newstate)
1662 #define PREFERRED_TILE_SIZE 30
1663 #define HALFSZ (ds->sz6*3)
1664 #define THIRDSZ (ds->sz6*2)
1665 #define TILE_SIZE (ds->sz6*6)
1667 #define BORDER (TILE_SIZE/8)
1668 #define BORDER_WIDTH (max(TILE_SIZE / 32, 1))
1670 #define COORD(x) ( (x+1) * TILE_SIZE + BORDER )
1671 #define CENTERED_COORD(x) ( COORD(x) + TILE_SIZE/2 )
1672 #define FROMCOORD(x) ( ((x) < BORDER) ? -1 : ( ((x) - BORDER) / TILE_SIZE) - 1 )
1674 #define DS_DSHIFT 4 /* R/U/L/D shift, for drag-in-progress flags */
1676 #define DS_ERROR (1 << 8)
1677 #define DS_CLUE (1 << 9)
1678 #define DS_NOTRACK (1 << 10)
1679 #define DS_FLASH (1 << 11)
1680 #define DS_CURSOR (1 << 12) /* cursor in square (centre, or on edge) */
1681 #define DS_TRACK (1 << 13)
1682 #define DS_CLEARING (1 << 14)
1684 #define DS_NSHIFT 16 /* R/U/L/D shift, for no-track edge flags */
1685 #define DS_CSHIFT 20 /* R/U/L/D shift, for cursor-on-edge */
1687 struct game_drawstate {
1692 unsigned int *flags, *flags_drag;
1696 static void update_ui_drag(const game_state *state, game_ui *ui, int gx, int gy)
1698 int w = state->p.w, h = state->p.h;
1699 int dx = abs(ui->drag_sx - gx), dy = abs(ui->drag_sy - gy);
1702 ui->drag_ex = gx < 0 ? 0 : gx >= w ? w-1 : gx;
1703 ui->drag_ey = ui->drag_sy;
1704 ui->dragging = TRUE;
1705 } else if (dx == 0) {
1706 ui->drag_ex = ui->drag_sx;
1707 ui->drag_ey = gy < 0 ? 0 : gy >= h ? h-1 : gy;
1708 ui->dragging = TRUE;
1710 ui->drag_ex = ui->drag_sx;
1711 ui->drag_ey = ui->drag_sy;
1712 ui->dragging = FALSE;
1716 static int ui_can_flip_edge(const game_state *state, int x, int y, int dir,
1719 int w = state->p.w /*, h = state->shared->h, sz = state->shared->sz */;
1720 int x2 = x + DX(dir);
1721 int y2 = y + DY(dir);
1722 unsigned int sf1, sf2, ef;
1724 if (!INGRID(state, x, y) || !INGRID(state, x2, y2))
1727 sf1 = state->sflags[y*w + x];
1728 sf2 = state->sflags[y2*w + x2];
1729 if ( !notrack && ((sf1 & S_CLUE) || (sf2 & S_CLUE)) )
1732 ef = S_E_FLAGS(state, x, y, dir);
1734 /* if we're going to _set_ NOTRACK (i.e. the flag is currently unset),
1735 make sure the edge is not already set to TRACK. The adjacent squares
1736 could be set to TRACK, because we don't know which edges the general
1737 square setting refers to. */
1738 if (!(ef & E_NOTRACK) && (ef & E_TRACK))
1741 if (!(ef & E_TRACK)) {
1742 /* if we're going to _set_ TRACK, make sure neither adjacent square nor
1743 the edge itself is already set to NOTRACK. */
1744 if ((sf1 & S_NOTRACK) || (sf2 & S_NOTRACK) || (ef & E_NOTRACK))
1746 /* if we're going to _set_ TRACK, make sure neither adjacent square has
1747 2 track flags already. */
1748 if ((S_E_COUNT(state, x, y, E_TRACK) >= 2) ||
1749 (S_E_COUNT(state, x2, y2, E_TRACK) >= 2))
1756 static int ui_can_flip_square(const game_state *state, int x, int y, int notrack)
1758 int w = state->p.w, trackc;
1761 if (!INGRID(state, x, y)) return FALSE;
1762 sf = state->sflags[y*w+x];
1763 trackc = S_E_COUNT(state, x, y, E_TRACK);
1765 if (sf & S_CLUE) return FALSE;
1768 /* If we're setting S_NOTRACK, we cannot have either S_TRACK or any E_TRACK. */
1769 if (!(sf & S_NOTRACK) && ((sf & S_TRACK) || (trackc > 0)))
1772 /* If we're setting S_TRACK, we cannot have any S_NOTRACK (we could have
1773 E_NOTRACK, though, because one or two wouldn't rule out a track) */
1774 if (!(sf & S_TRACK) && (sf & S_NOTRACK))
1780 static char *edge_flip_str(const game_state *state, int x, int y, int dir, int notrack, char *buf) {
1781 unsigned ef = S_E_FLAGS(state, x, y, dir);
1785 c = (ef & E_NOTRACK) ? 'n' : 'N';
1787 c = (ef & E_TRACK) ? 't' : 'T';
1789 sprintf(buf, "%c%c%d,%d", c, MOVECHAR(dir), x, y);
1793 static char *square_flip_str(const game_state *state, int x, int y, int notrack, char *buf) {
1794 unsigned f = state->sflags[y*state->p.w+x];
1798 c = (f & E_NOTRACK) ? 'n' : 'N';
1800 c = (f & E_TRACK) ? 't' : 'T';
1802 sprintf(buf, "%cS%d,%d", c, x, y);
1806 #define SIGN(x) ((x<0) ? -1 : (x>0))
1808 static game_state *copy_and_apply_drag(const game_state *state, const game_ui *ui)
1810 game_state *after = dup_game(state);
1811 int x1, y1, x2, y2, x, y, w = state->p.w;
1812 unsigned f = ui->notrack ? S_NOTRACK : S_TRACK, ff;
1814 x1 = min(ui->drag_sx, ui->drag_ex); x2 = max(ui->drag_sx, ui->drag_ex);
1815 y1 = min(ui->drag_sy, ui->drag_ey); y2 = max(ui->drag_sy, ui->drag_ey);
1817 /* actually either x1 == x2, or y1 == y2, but it's easier just to code
1819 for (x = x1; x <= x2; x++) {
1820 for (y = y1; y <= y2; y++) {
1821 ff = state->sflags[y*w+x];
1822 if (ui->clearing && !(ff & f))
1823 continue; /* nothing to do, clearing and already clear */
1824 else if (!ui->clearing && (ff & f))
1825 continue; /* nothing to do, setting and already set */
1826 else if (ui_can_flip_square(state, x, y, ui->notrack))
1827 after->sflags[y*w+x] ^= f;
1833 #define KEY_DIRECTION(btn) (\
1834 (btn) == CURSOR_DOWN ? D : (btn) == CURSOR_UP ? U :\
1835 (btn) == CURSOR_LEFT ? L : R)
1837 static char *interpret_move(const game_state *state, game_ui *ui,
1838 const game_drawstate *ds,
1839 int x, int y, int button)
1841 int w = state->p.w, h = state->p.h, direction;
1842 int gx = FROMCOORD(x), gy = FROMCOORD(y);
1845 /* --- mouse operations --- */
1847 if (IS_MOUSE_DOWN(button)) {
1848 ui->cursor_active = FALSE;
1849 ui->dragging = FALSE;
1851 if (!INGRID(state, gx, gy)) {
1852 /* can't drag from off grid */
1856 if (button == RIGHT_BUTTON) {
1858 ui->clearing = state->sflags[gy*w+gx] & S_NOTRACK;
1860 ui->notrack = FALSE;
1861 ui->clearing = state->sflags[gy*w+gx] & S_TRACK;
1866 ui->drag_sx = ui->drag_ex = gx;
1867 ui->drag_sy = ui->drag_ey = gy;
1872 if (IS_MOUSE_DRAG(button)) {
1873 ui->cursor_active = FALSE;
1874 update_ui_drag(state, ui, gx, gy);
1878 if (IS_MOUSE_RELEASE(button)) {
1879 ui->cursor_active = FALSE;
1881 (ui->drag_sx != ui->drag_ex || ui->drag_sy != ui->drag_ey)) {
1882 game_state *dragged = copy_and_apply_drag(state, ui);
1883 char *ret = move_string_diff(state, dragged, FALSE);
1892 /* We might still have been dragging (and just done a one-
1893 * square drag): cancel drag, so undo doesn't make it like
1894 * a drag-in-progress. */
1897 /* Click (or tiny drag). Work out which edge we were
1901 * We process clicks based on the mouse-down location,
1902 * because that's more natural for a user to carefully
1903 * control than the mouse-up.
1908 cx = CENTERED_COORD(gx);
1909 cy = CENTERED_COORD(gy);
1911 if (!INGRID(state, gx, gy) || FROMCOORD(x) != gx || FROMCOORD(y) != gy)
1914 if (max(abs(x-cx),abs(y-cy)) < TILE_SIZE/4) {
1915 if (ui_can_flip_square(state, gx, gy, button == RIGHT_RELEASE))
1916 return square_flip_str(state, gx, gy, button == RIGHT_RELEASE, tmpbuf);
1919 if (abs(x-cx) < abs(y-cy)) {
1920 /* Closest to top/bottom edge. */
1921 direction = (y < cy) ? U : D;
1923 /* Closest to left/right edge. */
1924 direction = (x < cx) ? L : R;
1926 if (ui_can_flip_edge(state, gx, gy, direction,
1927 button == RIGHT_RELEASE))
1928 return edge_flip_str(state, gx, gy, direction,
1929 button == RIGHT_RELEASE, tmpbuf);
1936 /* --- cursor/keyboard operations --- */
1938 if (IS_CURSOR_MOVE(button)) {
1939 int dx = (button == CURSOR_LEFT) ? -1 : ((button == CURSOR_RIGHT) ? +1 : 0);
1940 int dy = (button == CURSOR_DOWN) ? +1 : ((button == CURSOR_UP) ? -1 : 0);
1942 if (!ui->cursor_active) {
1943 ui->cursor_active = TRUE;
1947 ui->curx = ui->curx + dx;
1948 ui->cury = ui->cury + dy;
1949 if ((ui->curx % 2 == 0) && (ui->cury % 2 == 0)) {
1950 /* disallow cursor on square corners: centres and edges only */
1951 ui->curx += dx; ui->cury += dy;
1953 ui->curx = min(max(ui->curx, 1), 2*w-1);
1954 ui->cury = min(max(ui->cury, 1), 2*h-1);
1958 if (IS_CURSOR_SELECT(button)) {
1959 if (!ui->cursor_active) {
1960 ui->cursor_active = TRUE;
1963 /* click on square corner does nothing (shouldn't get here) */
1964 if ((ui->curx % 2) == 0 && (ui->cury % 2 == 0))
1969 direction = ((ui->curx % 2) == 0) ? L : ((ui->cury % 2) == 0) ? U : 0;
1972 ui_can_flip_edge(state, gx, gy, direction, button == CURSOR_SELECT2))
1973 return edge_flip_str(state, gx, gy, direction, button == CURSOR_SELECT2, tmpbuf);
1974 else if (!direction &&
1975 ui_can_flip_square(state, gx, gy, button == CURSOR_SELECT2))
1976 return square_flip_str(state, gx, gy, button == CURSOR_SELECT2, tmpbuf);
1981 /* helps to debug the solver */
1982 if (button == 'H' || button == 'h')
1989 static game_state *execute_move(const game_state *state, const char *move)
1991 int w = state->p.w, x, y, n, i;
1994 game_state *ret = dup_game(state);
1996 /* this is breaking the bank on GTK, which vsprintf's into a fixed-size buffer
1997 * which is 4096 bytes long. vsnprintf needs a feature-test macro to use, faff. */
1998 /*debug(("move: %s\n", move));*/
2003 ret->used_solve = TRUE;
2005 } else if (c == 'T' || c == 't' || c == 'N' || c == 'n') {
2006 /* set track, clear track; set notrack, clear notrack */
2008 if (sscanf(move, "%c%d,%d%n", &d, &x, &y, &n) != 3)
2010 if (!INGRID(state, x, y)) goto badmove;
2012 f = (c == 'T' || c == 't') ? S_TRACK : S_NOTRACK;
2015 if (c == 'T' || c == 'N')
2016 ret->sflags[y*w+x] |= f;
2018 ret->sflags[y*w+x] &= ~f;
2019 } else if (d == 'U' || d == 'D' || d == 'L' || d == 'R') {
2020 for (i = 0; i < 4; i++) {
2023 if (MOVECHAR(df) == d) {
2024 if (c == 'T' || c == 'N')
2025 S_E_SET(ret, x, y, df, f);
2027 S_E_CLEAR(ret, x, y, df, f);
2033 } else if (c == 'H') {
2034 tracks_solve(ret, DIFFCOUNT);
2045 check_completion(ret, TRUE);
2054 /* ----------------------------------------------------------------------
2058 #define FLASH_TIME 0.5F
2060 static void game_compute_size(const game_params *params, int tilesize,
2063 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
2067 ads.sz6 = tilesize/6;
2069 *x = (params->w+2) * TILE_SIZE + 2 * BORDER;
2070 *y = (params->h+2) * TILE_SIZE + 2 * BORDER;
2073 static void game_set_size(drawing *dr, game_drawstate *ds,
2074 const game_params *params, int tilesize)
2076 ds->sz6 = tilesize/6;
2080 COL_BACKGROUND, COL_LOWLIGHT, COL_HIGHLIGHT,
2081 COL_TRACK_BACKGROUND = COL_LOWLIGHT,
2082 COL_GRID, COL_CLUE, COL_CURSOR,
2083 COL_TRACK, COL_TRACK_CLUE, COL_SLEEPER,
2084 COL_DRAGON, COL_DRAGOFF,
2085 COL_ERROR, COL_FLASH,
2089 static float *game_colours(frontend *fe, int *ncolours)
2091 float *ret = snewn(3 * NCOLOURS, float);
2094 game_mkhighlight(fe, ret, COL_BACKGROUND, COL_HIGHLIGHT, COL_LOWLIGHT);
2096 for (i = 0; i < 3; i++) {
2097 ret[COL_TRACK_CLUE * 3 + i] = 0.0F;
2098 ret[COL_TRACK * 3 + i] = 0.5F;
2099 ret[COL_CLUE * 3 + i] = 0.0F;
2100 ret[COL_GRID * 3 + i] = 0.75F;
2101 ret[COL_CURSOR * 3 + i] = 0.6F;
2104 ret[COL_SLEEPER * 3 + 0] = 0.5F;
2105 ret[COL_SLEEPER * 3 + 1] = 0.4F;
2106 ret[COL_SLEEPER * 3 + 2] = 0.1F;
2108 ret[COL_ERROR * 3 + 0] = 1.0F;
2109 ret[COL_ERROR * 3 + 1] = 0.0F;
2110 ret[COL_ERROR * 3 + 2] = 0.0F;
2112 ret[COL_DRAGON * 3 + 0] = 0.0F;
2113 ret[COL_DRAGON * 3 + 1] = 0.0F;
2114 ret[COL_DRAGON * 3 + 2] = 1.0F;
2116 ret[COL_DRAGOFF * 3 + 0] = 0.8F;
2117 ret[COL_DRAGOFF * 3 + 1] = 0.8F;
2118 ret[COL_DRAGOFF * 3 + 2] = 1.0F;
2120 ret[COL_FLASH * 3 + 0] = 1.0F;
2121 ret[COL_FLASH * 3 + 1] = 1.0F;
2122 ret[COL_FLASH * 3 + 2] = 1.0F;
2124 *ncolours = NCOLOURS;
2128 static game_drawstate *game_new_drawstate(drawing *dr, const game_state *state)
2130 struct game_drawstate *ds = snew(struct game_drawstate);
2134 ds->started = FALSE;
2138 ds->sz = ds->w*ds->h;
2139 ds->flags = snewn(ds->sz, unsigned int);
2140 ds->flags_drag = snewn(ds->sz, unsigned int);
2141 for (i = 0; i < ds->sz; i++)
2142 ds->flags[i] = ds->flags_drag[i] = 0;
2144 ds->num_errors = snewn(ds->w+ds->h, int);
2145 for (i = 0; i < ds->w+ds->h; i++)
2146 ds->num_errors[i] = 0;
2151 static void game_free_drawstate(drawing *dr, game_drawstate *ds)
2154 sfree(ds->flags_drag);
2155 sfree(ds->num_errors);
2159 static void draw_circle_sleepers(drawing *dr, game_drawstate *ds,
2160 float cx, float cy, float r2, float thickness, int c)
2162 float qr6 = (float)PI/12, qr3 = (float)PI/6, th, x1, y1, x2, y2;
2163 float t6 = THIRDSZ/2.0F, r1 = t6;
2166 for (i = 0; i < 12; i++) {
2168 x1 = r1*(float)cos(th);
2169 x2 = r2*(float)cos(th);
2170 y1 = r1*(float)sin(th);
2171 y2 = r2*(float)sin(th);
2172 draw_thick_line(dr, thickness, cx+x1, cy+y1, cx+x2, cy+y2, c);
2176 static void draw_thick_circle_outline(drawing *dr, float thickness,
2177 float cx, float cy, float r,
2180 float circ4 = 0.5F * (float)PI * r, ang, x1, y1, x2, y2;
2183 nseg = (int)(circ4 / 4.0F)*4; /* ensure a quarter-circle has a whole #segs */
2184 ang = 2.0F*(float)PI / nseg;
2186 for (i = 0; i < nseg; i++) {
2187 float th = ang * i, th2 = ang * (i+1);
2188 x1 = cx + r*(float)cos(th);
2189 x2 = cx + r*(float)cos(th2);
2190 y1 = cy + r*(float)sin(th);
2191 y2 = cy + r*(float)sin(th2);
2192 debug(("circ outline: x=%.2f -> %.2f, thick=%.2f", x1, x2, thickness));
2193 draw_thick_line(dr, thickness, x1, y1, x2, y2, colour);
2197 static void draw_tracks_specific(drawing *dr, game_drawstate *ds,
2198 int x, int y, unsigned int flags,
2199 int ctrack, int csleeper)
2201 float ox = (float)COORD(x), oy = (float)COORD(y), cx, cy;
2202 float t1 = (float)TILE_SIZE, t3 = TILE_SIZE/3.0F, t6 = TILE_SIZE/6.0F;
2204 float thick_track = TILE_SIZE/8.0F, thick_sleeper = TILE_SIZE/12.0F;
2207 for (i = 1; i <= 7; i+=2) {
2208 cx = ox + TILE_SIZE/8.0F*i;
2209 draw_thick_line(dr, thick_sleeper,
2210 cx, oy+t6, cx, oy+t6+2*t3, csleeper);
2212 draw_thick_line(dr, thick_track, ox, oy + t3, ox + TILE_SIZE, oy + t3, ctrack);
2213 draw_thick_line(dr, thick_track, ox, oy + 2*t3, ox + TILE_SIZE, oy + 2*t3, ctrack);
2217 for (i = 1; i <= 7; i+=2) {
2218 cy = oy + TILE_SIZE/8.0F*i;
2219 draw_thick_line(dr, thick_sleeper,
2220 ox+t6, cy, ox+t6+2*t3, cy, csleeper);
2222 debug(("vert line: x=%.2f, thick=%.2f", ox + t3, thick_track));
2223 draw_thick_line(dr, thick_track, ox + t3, oy, ox + t3, oy + TILE_SIZE, ctrack);
2224 draw_thick_line(dr, thick_track, ox + 2*t3, oy, ox + 2*t3, oy + TILE_SIZE, ctrack);
2227 if (flags == UL || flags == DL || flags == UR || flags == DR) {
2228 cx = (flags & L) ? ox : ox + TILE_SIZE;
2229 cy = (flags & U) ? oy : oy + TILE_SIZE;
2231 draw_circle_sleepers(dr, ds, cx, cy, (float)(5*t6), thick_sleeper, csleeper);
2233 draw_thick_circle_outline(dr, thick_track, (float)cx, (float)cy,
2235 draw_thick_circle_outline(dr, thick_track, (float)cx, (float)cy,
2241 for (d = 1; d < 16; d *= 2) {
2242 float ox1 = 0, ox2 = 0, oy1 = 0, oy2 = 0;
2244 if (!(flags & d)) continue;
2246 for (i = 1; i <= 2; i++) {
2251 } else if (d == R) {
2253 ox2 = t1 - thick_track;
2255 } else if (d == U) {
2259 } else if (d == D) {
2262 oy2 = t1 - thick_track;
2264 draw_thick_line(dr, thick_track, ox+ox1, oy+oy1, ox+ox2, oy+oy2, ctrack);
2269 static unsigned int best_bits(unsigned int flags, unsigned int flags_drag, int *col)
2271 int nb_orig = nbits[flags & ALLDIR], nb_drag = nbits[flags_drag & ALLDIR];
2273 if (nb_orig > nb_drag) {
2275 return flags & ALLDIR;
2276 } else if (nb_orig < nb_drag) {
2278 return flags_drag & ALLDIR;
2280 return flags & ALLDIR; /* same number of bits: no special colour. */
2283 static void draw_square(drawing *dr, game_drawstate *ds,
2284 int x, int y, unsigned int flags, unsigned int flags_drag)
2286 int t2 = HALFSZ, t16 = HALFSZ/4, off;
2287 int ox = COORD(x), oy = COORD(y), cx = ox + t2, cy = oy + t2, d, c;
2288 int bg = (flags & DS_TRACK) ? COL_TRACK_BACKGROUND : COL_BACKGROUND;
2289 unsigned int flags_best;
2293 /* Clip to the grid square. */
2294 clip(dr, ox, oy, TILE_SIZE, TILE_SIZE);
2296 /* Clear the square. */
2297 best_bits((flags & DS_TRACK) == DS_TRACK,
2298 (flags_drag & DS_TRACK) == DS_TRACK, &bg);
2299 draw_rect(dr, ox, oy, TILE_SIZE, TILE_SIZE, bg);
2301 /* Draw outline of grid square */
2302 draw_line(dr, ox, oy, COORD(x+1), oy, COL_GRID);
2303 draw_line(dr, ox, oy, ox, COORD(y+1), COL_GRID);
2305 /* More outlines for clue squares. */
2306 if (flags & DS_CURSOR) {
2307 int curx, cury, curw, curh;
2310 curx = ox + off; cury = oy + off;
2311 curw = curh = TILE_SIZE - (2*off) + 1;
2313 if (flags & (U << DS_CSHIFT)) {
2314 cury = oy - off; curh = 2*off + 1;
2315 } else if (flags & (D << DS_CSHIFT)) {
2316 cury = oy + TILE_SIZE - off; curh = 2*off + 1;
2317 } else if (flags & (L << DS_CSHIFT)) {
2318 curx = ox - off; curw = 2*off + 1;
2319 } else if (flags & (R << DS_CSHIFT)) {
2320 curx = ox + TILE_SIZE - off; curw = 2*off + 1;
2323 draw_rect_outline(dr, curx, cury, curw, curh, COL_GRID);
2326 /* Draw tracks themselves */
2327 c = (flags & DS_ERROR) ? COL_ERROR :
2328 (flags & DS_FLASH) ? COL_FLASH :
2329 (flags & DS_CLUE) ? COL_TRACK_CLUE : COL_TRACK;
2330 flags_best = best_bits(flags, flags_drag, &c);
2331 draw_tracks_specific(dr, ds, x, y, flags_best, c, COL_SLEEPER);
2333 /* Draw no-track marks, if present, in square and on edges. */
2335 flags_best = best_bits((flags & DS_NOTRACK) == DS_NOTRACK,
2336 (flags_drag & DS_NOTRACK) == DS_NOTRACK, &c);
2339 draw_line(dr, cx - off, cy - off, cx + off, cy + off, c);
2340 draw_line(dr, cx - off, cy + off, cx + off, cy - off, c);
2344 flags_best = best_bits(flags >> DS_NSHIFT, flags_drag >> DS_NSHIFT, &c);
2345 for (d = 1; d < 16; d *= 2) {
2350 if (flags_best & d) {
2351 cx += (d == R) ? t2 : (d == L) ? -t2 : 0;
2352 cy += (d == D) ? t2 : (d == U) ? -t2 : 0;
2354 draw_line(dr, cx - off, cy - off, cx + off, cy + off, c);
2355 draw_line(dr, cx - off, cy + off, cx + off, cy - off, c);
2360 draw_update(dr, ox, oy, TILE_SIZE, TILE_SIZE);
2363 static void draw_clue(drawing *dr, game_drawstate *ds, int w, int clue, int i, int col)
2365 int cx, cy, tsz = TILE_SIZE/2;
2369 cx = CENTERED_COORD(i);
2370 cy = CENTERED_COORD(-1);
2372 cx = CENTERED_COORD(w);
2373 cy = CENTERED_COORD(i-w);
2376 draw_rect(dr, cx - tsz + BORDER, cy - tsz + BORDER,
2377 TILE_SIZE - BORDER, TILE_SIZE - BORDER, COL_BACKGROUND);
2378 sprintf(buf, "%d", clue);
2379 draw_text(dr, cx, cy, FONT_VARIABLE, tsz, ALIGN_VCENTRE|ALIGN_HCENTRE,
2381 draw_update(dr, cx - tsz, cy - tsz, TILE_SIZE, TILE_SIZE);
2384 static void draw_loop_ends(drawing *dr, game_drawstate *ds,
2385 const game_state *state, int c)
2387 int tsz = TILE_SIZE/2;
2389 draw_text(dr, CENTERED_COORD(-1), CENTERED_COORD(state->numbers->row_s),
2390 FONT_VARIABLE, tsz, ALIGN_VCENTRE|ALIGN_HCENTRE,
2393 draw_text(dr, CENTERED_COORD(state->numbers->col_s), CENTERED_COORD(state->p.h),
2394 FONT_VARIABLE, tsz, ALIGN_VCENTRE|ALIGN_HCENTRE,
2398 static unsigned int s2d_flags(const game_state *state, int x, int y, const game_ui *ui)
2403 f = S_E_DIRS(state, x, y, E_TRACK);
2404 f |= (S_E_DIRS(state, x, y, E_NOTRACK) << DS_NSHIFT);
2406 if (state->sflags[y*w+x] & S_ERROR)
2408 if (state->sflags[y*w+x] & S_CLUE)
2410 if (state->sflags[y*w+x] & S_NOTRACK)
2412 if ((state->sflags[y*w+x] & S_TRACK) || (S_E_COUNT(state, x, y, E_TRACK) > 0))
2415 if (ui->cursor_active) {
2416 if (ui->curx >= x*2 && ui->curx <= (x+1)*2 &&
2417 ui->cury >= y*2 && ui->cury <= (y+1)*2) {
2419 if (ui->curx == x*2) f |= (L << DS_CSHIFT);
2420 if (ui->curx == (x+1)*2) f |= (R << DS_CSHIFT);
2421 if (ui->cury == y*2) f |= (U << DS_CSHIFT);
2422 if (ui->cury == (y+1)*2) f |= (D << DS_CSHIFT);
2429 static void game_redraw(drawing *dr, game_drawstate *ds, const game_state *oldstate,
2430 const game_state *state, int dir, const game_ui *ui,
2431 float animtime, float flashtime)
2433 int i, x, y, force = 0, flashing = 0, w = ds->w, h = ds->h;
2434 game_state *drag_state = NULL;
2438 * The initial contents of the window are not guaranteed and
2439 * can vary with front ends. To be on the safe side, all games
2440 * should start by drawing a big background-colour rectangle
2441 * covering the whole window.
2443 draw_rect(dr, 0, 0, (w+2)*TILE_SIZE + 2*BORDER, (h+2)*TILE_SIZE + 2*BORDER,
2446 draw_loop_ends(dr, ds, state, COL_CLUE);
2448 draw_line(dr, COORD(ds->w), COORD(0), COORD(ds->w), COORD(ds->h), COL_GRID);
2449 draw_line(dr, COORD(0), COORD(ds->h), COORD(ds->w), COORD(ds->h), COL_GRID);
2451 draw_update(dr, 0, 0, (w+2)*TILE_SIZE + 2*BORDER, (h+2)*TILE_SIZE + 2*BORDER);
2457 for (i = 0; i < w+h; i++) {
2458 if (force || (state->num_errors[i] != ds->num_errors[i])) {
2459 ds->num_errors[i] = state->num_errors[i];
2460 draw_clue(dr, ds, w, state->numbers->numbers[i], i,
2461 ds->num_errors[i] ? COL_ERROR : COL_CLUE);
2465 if (flashtime > 0 &&
2466 (flashtime <= FLASH_TIME/3 ||
2467 flashtime >= FLASH_TIME*2/3))
2468 flashing = DS_FLASH;
2471 drag_state = copy_and_apply_drag(state, ui);
2473 for (x = 0; x < w; x++) {
2474 for (y = 0; y < h; y++) {
2475 unsigned int f, f_d;
2477 f = s2d_flags(state, x, y, ui) | flashing;
2478 f_d = drag_state ? s2d_flags(drag_state, x, y, ui) : f;
2480 if (f != ds->flags[y*w+x] || f_d != ds->flags_drag[y*w+x] || force) {
2481 ds->flags[y*w+x] = f;
2482 ds->flags_drag[y*w+x] = f_d;
2483 draw_square(dr, ds, x, y, f, f_d);
2488 if (drag_state) free_game(drag_state);
2491 static float game_anim_length(const game_state *oldstate, const game_state *newstate,
2492 int dir, game_ui *ui)
2497 static float game_flash_length(const game_state *oldstate, const game_state *newstate,
2498 int dir, game_ui *ui)
2500 if (!oldstate->completed &&
2501 newstate->completed && !newstate->used_solve)
2507 static int game_status(const game_state *state)
2509 return state->completed ? +1 : 0;
2512 static int game_timing_state(const game_state *state, game_ui *ui)
2517 static void game_print_size(const game_params *params, float *x, float *y)
2521 /* The Times uses 7mm squares */
2522 game_compute_size(params, 700, &pw, &ph);
2527 static void game_print(drawing *dr, const game_state *state, int tilesize)
2529 int w = state->p.w, h = state->p.h;
2530 int black = print_mono_colour(dr, 0), grey = print_grey_colour(dr, 0.5F);
2533 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
2534 game_drawstate ads, *ds = &ads;
2535 game_set_size(dr, ds, NULL, tilesize);
2537 /* Grid, then border (second so it is on top) */
2538 print_line_width(dr, TILE_SIZE / 24);
2539 for (x = 1; x < w; x++)
2540 draw_line(dr, COORD(x), COORD(0), COORD(x), COORD(h), grey);
2541 for (y = 1; y < h; y++)
2542 draw_line(dr, COORD(0), COORD(y), COORD(w), COORD(y), grey);
2544 print_line_width(dr, TILE_SIZE / 16);
2545 draw_rect_outline(dr, COORD(0), COORD(0), w*TILE_SIZE, h*TILE_SIZE, black);
2547 print_line_width(dr, TILE_SIZE / 24);
2549 /* clue numbers, and loop ends */
2550 for (i = 0; i < w+h; i++)
2551 draw_clue(dr, ds, w, state->numbers->numbers[i], i, black);
2552 draw_loop_ends(dr, ds, state, black);
2554 /* clue tracks / solution */
2555 for (x = 0; x < w; x++) {
2556 for (y = 0; y < h; y++) {
2557 clip(dr, COORD(x), COORD(y), TILE_SIZE, TILE_SIZE);
2558 draw_tracks_specific(dr, ds, x, y, S_E_DIRS(state, x, y, E_TRACK),
2566 #define thegame tracks
2569 const struct game thegame = {
2570 "Train Tracks", "games.tracks", "tracks",
2577 TRUE, game_configure, custom_params,
2585 TRUE, game_can_format_as_text_now, game_text_format,
2593 PREFERRED_TILE_SIZE, game_compute_size, game_set_size,
2596 game_free_drawstate,
2601 TRUE, FALSE, game_print_size, game_print,
2602 FALSE, /* wants_statusbar */
2603 FALSE, game_timing_state,
2607 /* vim: set shiftwidth=4 tabstop=8: */