New upstream release
[sgt-puzzles/ydirson.git] / fifteen.c
blobd3a02f390b6463a0c27a38ac0af376753d0f6ab5
1 /*
2 * fifteen.c: standard 15-puzzle.
3 */
5 #include <stdio.h>
6 #include <stdlib.h>
7 #include <string.h>
8 #include <assert.h>
9 #include <ctype.h>
10 #include <math.h>
12 #include "puzzles.h"
14 #define PREFERRED_TILE_SIZE 48
15 #define TILE_SIZE (ds->tilesize)
16 #define BORDER (TILE_SIZE / 2)
17 #define HIGHLIGHT_WIDTH (TILE_SIZE / 20)
18 #define COORD(x) ( (x) * TILE_SIZE + BORDER )
19 #define FROMCOORD(x) ( ((x) - BORDER + TILE_SIZE) / TILE_SIZE - 1 )
21 #define ANIM_TIME 0.13F
22 #define FLASH_FRAME 0.13F
24 #define X(state, i) ( (i) % (state)->w )
25 #define Y(state, i) ( (i) / (state)->w )
26 #define C(state, x, y) ( (y) * (state)->w + (x) )
28 enum {
29 COL_BACKGROUND,
30 COL_TEXT,
31 COL_HIGHLIGHT,
32 COL_LOWLIGHT,
33 NCOLOURS
36 struct game_params {
37 int w, h;
40 struct game_state {
41 int w, h, n;
42 int *tiles;
43 int gap_pos;
44 int completed;
45 int used_solve; /* used to suppress completion flash */
46 int movecount;
49 static game_params *default_params(void)
51 game_params *ret = snew(game_params);
53 ret->w = ret->h = 4;
55 return ret;
58 static int game_fetch_preset(int i, char **name, game_params **params)
60 return FALSE;
63 static void free_params(game_params *params)
65 sfree(params);
68 static game_params *dup_params(game_params *params)
70 game_params *ret = snew(game_params);
71 *ret = *params; /* structure copy */
72 return ret;
75 static void decode_params(game_params *ret, char const *string)
77 ret->w = ret->h = atoi(string);
78 while (*string && isdigit((unsigned char)*string)) string++;
79 if (*string == 'x') {
80 string++;
81 ret->h = atoi(string);
85 static char *encode_params(game_params *params, int full)
87 char data[256];
89 sprintf(data, "%dx%d", params->w, params->h);
91 return dupstr(data);
94 static config_item *game_configure(game_params *params)
96 config_item *ret;
97 char buf[80];
99 ret = snewn(3, config_item);
101 ret[0].name = "Width";
102 ret[0].type = C_STRING;
103 sprintf(buf, "%d", params->w);
104 ret[0].sval = dupstr(buf);
105 ret[0].ival = 0;
107 ret[1].name = "Height";
108 ret[1].type = C_STRING;
109 sprintf(buf, "%d", params->h);
110 ret[1].sval = dupstr(buf);
111 ret[1].ival = 0;
113 ret[2].name = NULL;
114 ret[2].type = C_END;
115 ret[2].sval = NULL;
116 ret[2].ival = 0;
118 return ret;
121 static game_params *custom_params(config_item *cfg)
123 game_params *ret = snew(game_params);
125 ret->w = atoi(cfg[0].sval);
126 ret->h = atoi(cfg[1].sval);
128 return ret;
131 static char *validate_params(game_params *params, int full)
133 if (params->w < 2 || params->h < 2)
134 return "Width and height must both be at least two";
136 return NULL;
139 static int perm_parity(int *perm, int n)
141 int i, j, ret;
143 ret = 0;
145 for (i = 0; i < n-1; i++)
146 for (j = i+1; j < n; j++)
147 if (perm[i] > perm[j])
148 ret = !ret;
150 return ret;
153 static char *new_game_desc(game_params *params, random_state *rs,
154 char **aux, int interactive)
156 int gap, n, i, x;
157 int x1, x2, p1, p2, parity;
158 int *tiles, *used;
159 char *ret;
160 int retlen;
162 n = params->w * params->h;
164 tiles = snewn(n, int);
165 used = snewn(n, int);
167 for (i = 0; i < n; i++) {
168 tiles[i] = -1;
169 used[i] = FALSE;
172 gap = random_upto(rs, n);
173 tiles[gap] = 0;
174 used[0] = TRUE;
177 * Place everything else except the last two tiles.
179 for (x = 0, i = n-1; i > 2; i--) {
180 int k = random_upto(rs, i);
181 int j;
183 for (j = 0; j < n; j++)
184 if (!used[j] && (k-- == 0))
185 break;
187 assert(j < n && !used[j]);
188 used[j] = TRUE;
190 while (tiles[x] >= 0)
191 x++;
192 assert(x < n);
193 tiles[x] = j;
197 * Find the last two locations, and the last two pieces.
199 while (tiles[x] >= 0)
200 x++;
201 assert(x < n);
202 x1 = x;
203 x++;
204 while (tiles[x] >= 0)
205 x++;
206 assert(x < n);
207 x2 = x;
209 for (i = 0; i < n; i++)
210 if (!used[i])
211 break;
212 p1 = i;
213 for (i = p1+1; i < n; i++)
214 if (!used[i])
215 break;
216 p2 = i;
219 * Determine the required parity of the overall permutation.
220 * This is the XOR of:
222 * - The chessboard parity ((x^y)&1) of the gap square. The
223 * bottom right counts as even.
225 * - The parity of n. (The target permutation is 1,...,n-1,0
226 * rather than 0,...,n-1; this is a cyclic permutation of
227 * the starting point and hence is odd iff n is even.)
229 parity = ((X(params, gap) - (params->w-1)) ^
230 (Y(params, gap) - (params->h-1)) ^
231 (n+1)) & 1;
234 * Try the last two tiles one way round. If that fails, swap
235 * them.
237 tiles[x1] = p1;
238 tiles[x2] = p2;
239 if (perm_parity(tiles, n) != parity) {
240 tiles[x1] = p2;
241 tiles[x2] = p1;
242 assert(perm_parity(tiles, n) == parity);
246 * Now construct the game description, by describing the tile
247 * array as a simple sequence of comma-separated integers.
249 ret = NULL;
250 retlen = 0;
251 for (i = 0; i < n; i++) {
252 char buf[80];
253 int k;
255 k = sprintf(buf, "%d,", tiles[i]);
257 ret = sresize(ret, retlen + k + 1, char);
258 strcpy(ret + retlen, buf);
259 retlen += k;
261 ret[retlen-1] = '\0'; /* delete last comma */
263 sfree(tiles);
264 sfree(used);
266 return ret;
269 static char *validate_desc(game_params *params, char *desc)
271 char *p, *err;
272 int i, area;
273 int *used;
275 area = params->w * params->h;
276 p = desc;
277 err = NULL;
279 used = snewn(area, int);
280 for (i = 0; i < area; i++)
281 used[i] = FALSE;
283 for (i = 0; i < area; i++) {
284 char *q = p;
285 int n;
287 if (*p < '0' || *p > '9') {
288 err = "Not enough numbers in string";
289 goto leave;
291 while (*p >= '0' && *p <= '9')
292 p++;
293 if (i < area-1 && *p != ',') {
294 err = "Expected comma after number";
295 goto leave;
297 else if (i == area-1 && *p) {
298 err = "Excess junk at end of string";
299 goto leave;
301 n = atoi(q);
302 if (n < 0 || n >= area) {
303 err = "Number out of range";
304 goto leave;
306 if (used[n]) {
307 err = "Number used twice";
308 goto leave;
310 used[n] = TRUE;
312 if (*p) p++; /* eat comma */
315 leave:
316 sfree(used);
317 return err;
320 static game_state *new_game(midend *me, game_params *params, char *desc)
322 game_state *state = snew(game_state);
323 int i;
324 char *p;
326 state->w = params->w;
327 state->h = params->h;
328 state->n = params->w * params->h;
329 state->tiles = snewn(state->n, int);
331 state->gap_pos = 0;
332 p = desc;
333 i = 0;
334 for (i = 0; i < state->n; i++) {
335 assert(*p);
336 state->tiles[i] = atoi(p);
337 if (state->tiles[i] == 0)
338 state->gap_pos = i;
339 while (*p && *p != ',')
340 p++;
341 if (*p) p++; /* eat comma */
343 assert(!*p);
344 assert(state->tiles[state->gap_pos] == 0);
346 state->completed = state->movecount = 0;
347 state->used_solve = FALSE;
349 return state;
352 static game_state *dup_game(game_state *state)
354 game_state *ret = snew(game_state);
356 ret->w = state->w;
357 ret->h = state->h;
358 ret->n = state->n;
359 ret->tiles = snewn(state->w * state->h, int);
360 memcpy(ret->tiles, state->tiles, state->w * state->h * sizeof(int));
361 ret->gap_pos = state->gap_pos;
362 ret->completed = state->completed;
363 ret->movecount = state->movecount;
364 ret->used_solve = state->used_solve;
366 return ret;
369 static void free_game(game_state *state)
371 sfree(state->tiles);
372 sfree(state);
375 static char *solve_game(game_state *state, game_state *currstate,
376 char *aux, char **error)
378 return dupstr("S");
381 static char *game_text_format(game_state *state)
383 char *ret, *p, buf[80];
384 int x, y, col, maxlen;
387 * First work out how many characters we need to display each
388 * number.
390 col = sprintf(buf, "%d", state->n-1);
393 * Now we know the exact total size of the grid we're going to
394 * produce: it's got h rows, each containing w lots of col, w-1
395 * spaces and a trailing newline.
397 maxlen = state->h * state->w * (col+1);
399 ret = snewn(maxlen+1, char);
400 p = ret;
402 for (y = 0; y < state->h; y++) {
403 for (x = 0; x < state->w; x++) {
404 int v = state->tiles[state->w*y+x];
405 if (v == 0)
406 sprintf(buf, "%*s", col, "");
407 else
408 sprintf(buf, "%*d", col, v);
409 memcpy(p, buf, col);
410 p += col;
411 if (x+1 == state->w)
412 *p++ = '\n';
413 else
414 *p++ = ' ';
418 assert(p - ret == maxlen);
419 *p = '\0';
420 return ret;
423 static game_ui *new_ui(game_state *state)
425 return NULL;
428 static void free_ui(game_ui *ui)
432 static char *encode_ui(game_ui *ui)
434 return NULL;
437 static void decode_ui(game_ui *ui, char *encoding)
441 static void game_changed_state(game_ui *ui, game_state *oldstate,
442 game_state *newstate)
446 struct game_drawstate {
447 int started;
448 int w, h, bgcolour;
449 int *tiles;
450 int tilesize;
453 static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds,
454 int x, int y, int button)
456 int gx, gy, dx, dy;
457 char buf[80];
459 button &= ~MOD_MASK;
461 gx = X(state, state->gap_pos);
462 gy = Y(state, state->gap_pos);
464 if (button == CURSOR_RIGHT && gx > 0)
465 dx = gx - 1, dy = gy;
466 else if (button == CURSOR_LEFT && gx < state->w-1)
467 dx = gx + 1, dy = gy;
468 else if (button == CURSOR_DOWN && gy > 0)
469 dy = gy - 1, dx = gx;
470 else if (button == CURSOR_UP && gy < state->h-1)
471 dy = gy + 1, dx = gx;
472 else if (button == LEFT_BUTTON) {
473 dx = FROMCOORD(x);
474 dy = FROMCOORD(y);
475 if (dx < 0 || dx >= state->w || dy < 0 || dy >= state->h)
476 return NULL; /* out of bounds */
478 * Any click location should be equal to the gap location
479 * in _precisely_ one coordinate.
481 if ((dx == gx && dy == gy) || (dx != gx && dy != gy))
482 return NULL;
483 } else
484 return NULL; /* no move */
486 sprintf(buf, "M%d,%d", dx, dy);
487 return dupstr(buf);
490 static game_state *execute_move(game_state *from, char *move)
492 int gx, gy, dx, dy, ux, uy, up, p;
493 game_state *ret;
495 if (!strcmp(move, "S")) {
496 int i;
498 ret = dup_game(from);
501 * Simply replace the grid with a solved one. For this game,
502 * this isn't a useful operation for actually telling the user
503 * what they should have done, but it is useful for
504 * conveniently being able to get hold of a clean state from
505 * which to practise manoeuvres.
507 for (i = 0; i < ret->n; i++)
508 ret->tiles[i] = (i+1) % ret->n;
509 ret->gap_pos = ret->n-1;
510 ret->used_solve = TRUE;
511 ret->completed = ret->movecount = 1;
513 return ret;
516 gx = X(from, from->gap_pos);
517 gy = Y(from, from->gap_pos);
519 if (move[0] != 'M' ||
520 sscanf(move+1, "%d,%d", &dx, &dy) != 2 ||
521 (dx == gx && dy == gy) || (dx != gx && dy != gy) ||
522 dx < 0 || dx >= from->w || dy < 0 || dy >= from->h)
523 return NULL;
526 * Find the unit displacement from the original gap
527 * position towards this one.
529 ux = (dx < gx ? -1 : dx > gx ? +1 : 0);
530 uy = (dy < gy ? -1 : dy > gy ? +1 : 0);
531 up = C(from, ux, uy);
533 ret = dup_game(from);
535 ret->gap_pos = C(from, dx, dy);
536 assert(ret->gap_pos >= 0 && ret->gap_pos < ret->n);
538 ret->tiles[ret->gap_pos] = 0;
540 for (p = from->gap_pos; p != ret->gap_pos; p += up) {
541 assert(p >= 0 && p < from->n);
542 ret->tiles[p] = from->tiles[p + up];
543 ret->movecount++;
547 * See if the game has been completed.
549 if (!ret->completed) {
550 ret->completed = ret->movecount;
551 for (p = 0; p < ret->n; p++)
552 if (ret->tiles[p] != (p < ret->n-1 ? p+1 : 0))
553 ret->completed = 0;
556 return ret;
559 /* ----------------------------------------------------------------------
560 * Drawing routines.
563 static void game_compute_size(game_params *params, int tilesize,
564 int *x, int *y)
566 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
567 struct { int tilesize; } ads, *ds = &ads;
568 ads.tilesize = tilesize;
570 *x = TILE_SIZE * params->w + 2 * BORDER;
571 *y = TILE_SIZE * params->h + 2 * BORDER;
574 static void game_set_size(drawing *dr, game_drawstate *ds,
575 game_params *params, int tilesize)
577 ds->tilesize = tilesize;
580 static float *game_colours(frontend *fe, int *ncolours)
582 float *ret = snewn(3 * NCOLOURS, float);
583 int i;
585 game_mkhighlight(fe, ret, COL_BACKGROUND, COL_HIGHLIGHT, COL_LOWLIGHT);
587 for (i = 0; i < 3; i++)
588 ret[COL_TEXT * 3 + i] = 0.0;
590 *ncolours = NCOLOURS;
591 return ret;
594 static game_drawstate *game_new_drawstate(drawing *dr, game_state *state)
596 struct game_drawstate *ds = snew(struct game_drawstate);
597 int i;
599 ds->started = FALSE;
600 ds->w = state->w;
601 ds->h = state->h;
602 ds->bgcolour = COL_BACKGROUND;
603 ds->tiles = snewn(ds->w*ds->h, int);
604 ds->tilesize = 0; /* haven't decided yet */
605 for (i = 0; i < ds->w*ds->h; i++)
606 ds->tiles[i] = -1;
608 return ds;
611 static void game_free_drawstate(drawing *dr, game_drawstate *ds)
613 sfree(ds->tiles);
614 sfree(ds);
617 static void draw_tile(drawing *dr, game_drawstate *ds, game_state *state,
618 int x, int y, int tile, int flash_colour)
620 if (tile == 0) {
621 draw_rect(dr, x, y, TILE_SIZE, TILE_SIZE,
622 flash_colour);
623 } else {
624 int coords[6];
625 char str[40];
627 coords[0] = x + TILE_SIZE - 1;
628 coords[1] = y + TILE_SIZE - 1;
629 coords[2] = x + TILE_SIZE - 1;
630 coords[3] = y;
631 coords[4] = x;
632 coords[5] = y + TILE_SIZE - 1;
633 draw_polygon(dr, coords, 3, COL_LOWLIGHT, COL_LOWLIGHT);
635 coords[0] = x;
636 coords[1] = y;
637 draw_polygon(dr, coords, 3, COL_HIGHLIGHT, COL_HIGHLIGHT);
639 draw_rect(dr, x + HIGHLIGHT_WIDTH, y + HIGHLIGHT_WIDTH,
640 TILE_SIZE - 2*HIGHLIGHT_WIDTH, TILE_SIZE - 2*HIGHLIGHT_WIDTH,
641 flash_colour);
643 sprintf(str, "%d", tile);
644 draw_text(dr, x + TILE_SIZE/2, y + TILE_SIZE/2,
645 FONT_VARIABLE, TILE_SIZE/3, ALIGN_VCENTRE | ALIGN_HCENTRE,
646 COL_TEXT, str);
648 draw_update(dr, x, y, TILE_SIZE, TILE_SIZE);
651 static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate,
652 game_state *state, int dir, game_ui *ui,
653 float animtime, float flashtime)
655 int i, pass, bgcolour;
657 if (flashtime > 0) {
658 int frame = (int)(flashtime / FLASH_FRAME);
659 bgcolour = (frame % 2 ? COL_LOWLIGHT : COL_HIGHLIGHT);
660 } else
661 bgcolour = COL_BACKGROUND;
663 if (!ds->started) {
664 int coords[10];
666 draw_rect(dr, 0, 0,
667 TILE_SIZE * state->w + 2 * BORDER,
668 TILE_SIZE * state->h + 2 * BORDER, COL_BACKGROUND);
669 draw_update(dr, 0, 0,
670 TILE_SIZE * state->w + 2 * BORDER,
671 TILE_SIZE * state->h + 2 * BORDER);
674 * Recessed area containing the whole puzzle.
676 coords[0] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
677 coords[1] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
678 coords[2] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
679 coords[3] = COORD(0) - HIGHLIGHT_WIDTH;
680 coords[4] = coords[2] - TILE_SIZE;
681 coords[5] = coords[3] + TILE_SIZE;
682 coords[8] = COORD(0) - HIGHLIGHT_WIDTH;
683 coords[9] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
684 coords[6] = coords[8] + TILE_SIZE;
685 coords[7] = coords[9] - TILE_SIZE;
686 draw_polygon(dr, coords, 5, COL_HIGHLIGHT, COL_HIGHLIGHT);
688 coords[1] = COORD(0) - HIGHLIGHT_WIDTH;
689 coords[0] = COORD(0) - HIGHLIGHT_WIDTH;
690 draw_polygon(dr, coords, 5, COL_LOWLIGHT, COL_LOWLIGHT);
692 ds->started = TRUE;
696 * Now draw each tile. We do this in two passes to make
697 * animation easy.
699 for (pass = 0; pass < 2; pass++) {
700 for (i = 0; i < state->n; i++) {
701 int t, t0;
703 * Figure out what should be displayed at this
704 * location. It's either a simple tile, or it's a
705 * transition between two tiles (in which case we say
706 * -1 because it must always be drawn).
709 if (oldstate && oldstate->tiles[i] != state->tiles[i])
710 t = -1;
711 else
712 t = state->tiles[i];
714 t0 = t;
716 if (ds->bgcolour != bgcolour || /* always redraw when flashing */
717 ds->tiles[i] != t || ds->tiles[i] == -1 || t == -1) {
718 int x, y;
721 * Figure out what to _actually_ draw, and where to
722 * draw it.
724 if (t == -1) {
725 int x0, y0, x1, y1;
726 int j;
729 * On the first pass, just blank the tile.
731 if (pass == 0) {
732 x = COORD(X(state, i));
733 y = COORD(Y(state, i));
734 t = 0;
735 } else {
736 float c;
738 t = state->tiles[i];
741 * Don't bother moving the gap; just don't
742 * draw it.
744 if (t == 0)
745 continue;
748 * Find the coordinates of this tile in the old and
749 * new states.
751 x1 = COORD(X(state, i));
752 y1 = COORD(Y(state, i));
753 for (j = 0; j < oldstate->n; j++)
754 if (oldstate->tiles[j] == state->tiles[i])
755 break;
756 assert(j < oldstate->n);
757 x0 = COORD(X(state, j));
758 y0 = COORD(Y(state, j));
760 c = (animtime / ANIM_TIME);
761 if (c < 0.0F) c = 0.0F;
762 if (c > 1.0F) c = 1.0F;
764 x = x0 + (int)(c * (x1 - x0));
765 y = y0 + (int)(c * (y1 - y0));
768 } else {
769 if (pass == 0)
770 continue;
771 x = COORD(X(state, i));
772 y = COORD(Y(state, i));
775 draw_tile(dr, ds, state, x, y, t, bgcolour);
777 ds->tiles[i] = t0;
780 ds->bgcolour = bgcolour;
783 * Update the status bar.
786 char statusbuf[256];
789 * Don't show the new status until we're also showing the
790 * new _state_ - after the game animation is complete.
792 if (oldstate)
793 state = oldstate;
795 if (state->used_solve)
796 sprintf(statusbuf, "Moves since auto-solve: %d",
797 state->movecount - state->completed);
798 else
799 sprintf(statusbuf, "%sMoves: %d",
800 (state->completed ? "COMPLETED! " : ""),
801 (state->completed ? state->completed : state->movecount));
803 status_bar(dr, statusbuf);
807 static float game_anim_length(game_state *oldstate,
808 game_state *newstate, int dir, game_ui *ui)
810 return ANIM_TIME;
813 static float game_flash_length(game_state *oldstate,
814 game_state *newstate, int dir, game_ui *ui)
816 if (!oldstate->completed && newstate->completed &&
817 !oldstate->used_solve && !newstate->used_solve)
818 return 2 * FLASH_FRAME;
819 else
820 return 0.0F;
823 static int game_timing_state(game_state *state, game_ui *ui)
825 return TRUE;
828 static void game_print_size(game_params *params, float *x, float *y)
832 static void game_print(drawing *dr, game_state *state, int tilesize)
836 #ifdef COMBINED
837 #define thegame fifteen
838 #endif
840 const struct game thegame = {
841 "Fifteen", "games.fifteen", "fifteen",
842 default_params,
843 game_fetch_preset,
844 decode_params,
845 encode_params,
846 free_params,
847 dup_params,
848 TRUE, game_configure, custom_params,
849 validate_params,
850 new_game_desc,
851 validate_desc,
852 new_game,
853 dup_game,
854 free_game,
855 TRUE, solve_game,
856 TRUE, game_text_format,
857 new_ui,
858 free_ui,
859 encode_ui,
860 decode_ui,
861 game_changed_state,
862 interpret_move,
863 execute_move,
864 PREFERRED_TILE_SIZE, game_compute_size, game_set_size,
865 game_colours,
866 game_new_drawstate,
867 game_free_drawstate,
868 game_redraw,
869 game_anim_length,
870 game_flash_length,
871 FALSE, FALSE, game_print_size, game_print,
872 TRUE, /* wants_statusbar */
873 FALSE, game_timing_state,
874 0, /* flags */