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Added a status bar.
[sgt/puzzles] / fifteen.c
1 /*
2 * fifteen.c: standard 15-puzzle.
3 */
4
5 #include <stdio.h>
6 #include <stdlib.h>
7 #include <string.h>
8 #include <assert.h>
9 #include <math.h>
10
11 #include "puzzles.h"
12
13 const char *const game_name = "Fifteen";
14
15 #define TILE_SIZE 48
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 )
20
21 #define ANIM_TIME 0.1F
22 #define FLASH_FRAME 0.1F
23
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) )
27
28 enum {
29 COL_BACKGROUND,
30 COL_TEXT,
31 COL_HIGHLIGHT,
32 COL_LOWLIGHT,
33 NCOLOURS
34 };
35
36 struct game_params {
37 int w, h;
38 };
39
40 struct game_state {
41 int w, h, n;
42 int *tiles;
43 int gap_pos;
44 int completed;
45 int movecount;
46 };
47
48 game_params *default_params(void)
49 {
50 game_params *ret = snew(game_params);
51
52 ret->w = ret->h = 4;
53
54 return ret;
55 }
56
57 int game_fetch_preset(int i, char **name, game_params **params)
58 {
59 return FALSE;
60 }
61
62 void free_params(game_params *params)
63 {
64 sfree(params);
65 }
66
67 game_params *dup_params(game_params *params)
68 {
69 game_params *ret = snew(game_params);
70 *ret = *params; /* structure copy */
71 return ret;
72 }
73
74 int perm_parity(int *perm, int n)
75 {
76 int i, j, ret;
77
78 ret = 0;
79
80 for (i = 0; i < n-1; i++)
81 for (j = i+1; j < n; j++)
82 if (perm[i] > perm[j])
83 ret = !ret;
84
85 return ret;
86 }
87
88 char *new_game_seed(game_params *params)
89 {
90 int gap, n, i, x;
91 int x1, x2, p1, p2, parity;
92 int *tiles, *used;
93 char *ret;
94 int retlen;
95
96 n = params->w * params->h;
97
98 tiles = snewn(n, int);
99 used = snewn(n, int);
100
101 for (i = 0; i < n; i++) {
102 tiles[i] = -1;
103 used[i] = FALSE;
104 }
105
106 gap = rand_upto(n);
107 tiles[gap] = 0;
108 used[0] = TRUE;
109
110 /*
111 * Place everything else except the last two tiles.
112 */
113 for (x = 0, i = n-1; i > 2; i--) {
114 int k = rand_upto(i);
115 int j;
116
117 for (j = 0; j < n; j++)
118 if (!used[j] && (k-- == 0))
119 break;
120
121 assert(j < n && !used[j]);
122 used[j] = TRUE;
123
124 while (tiles[x] >= 0)
125 x++;
126 assert(x < n);
127 tiles[x] = j;
128 }
129
130 /*
131 * Find the last two locations, and the last two pieces.
132 */
133 while (tiles[x] >= 0)
134 x++;
135 assert(x < n);
136 x1 = x;
137 x++;
138 while (tiles[x] >= 0)
139 x++;
140 assert(x < n);
141 x2 = x;
142
143 for (i = 0; i < n; i++)
144 if (!used[i])
145 break;
146 p1 = i;
147 for (i = p1+1; i < n; i++)
148 if (!used[i])
149 break;
150 p2 = i;
151
152 /*
153 * Determine the required parity of the overall permutation.
154 * This is the XOR of:
155 *
156 * - The chessboard parity ((x^y)&1) of the gap square. The
157 * bottom right, and therefore also the top left, count as
158 * even.
159 *
160 * - The parity of n. (The target permutation is 1,...,n-1,0
161 * rather than 0,...,n-1; this is a cyclic permutation of
162 * the starting point and hence is odd iff n is even.)
163 */
164 parity = (X(params, gap) ^ Y(params, gap) ^ (n+1)) & 1;
165
166 /*
167 * Try the last two tiles one way round. If that fails, swap
168 * them.
169 */
170 tiles[x1] = p1;
171 tiles[x2] = p2;
172 if (perm_parity(tiles, n) != parity) {
173 tiles[x1] = p2;
174 tiles[x2] = p1;
175 assert(perm_parity(tiles, n) == parity);
176 }
177
178 /*
179 * Now construct the game seed, by describing the tile array as
180 * a simple sequence of comma-separated integers.
181 */
182 ret = NULL;
183 retlen = 0;
184 for (i = 0; i < n; i++) {
185 char buf[80];
186 int k;
187
188 k = sprintf(buf, "%d,", tiles[i]);
189
190 ret = sresize(ret, retlen + k + 1, char);
191 strcpy(ret + retlen, buf);
192 retlen += k;
193 }
194 ret[retlen-1] = '\0'; /* delete last comma */
195
196 sfree(tiles);
197 sfree(used);
198
199 return ret;
200 }
201
202 game_state *new_game(game_params *params, char *seed)
203 {
204 game_state *state = snew(game_state);
205 int i;
206 char *p;
207
208 state->w = params->w;
209 state->h = params->h;
210 state->n = params->w * params->h;
211 state->tiles = snewn(state->n, int);
212
213 state->gap_pos = 0;
214 p = seed;
215 i = 0;
216 for (i = 0; i < state->n; i++) {
217 assert(*p);
218 state->tiles[i] = atoi(p);
219 if (state->tiles[i] == 0)
220 state->gap_pos = i;
221 while (*p && *p != ',')
222 p++;
223 if (*p) p++; /* eat comma */
224 }
225 assert(!*p);
226 assert(state->tiles[state->gap_pos] == 0);
227
228 state->completed = state->movecount = 0;
229
230 return state;
231 }
232
233 game_state *dup_game(game_state *state)
234 {
235 game_state *ret = snew(game_state);
236
237 ret->w = state->w;
238 ret->h = state->h;
239 ret->n = state->n;
240 ret->tiles = snewn(state->w * state->h, int);
241 memcpy(ret->tiles, state->tiles, state->w * state->h * sizeof(int));
242 ret->gap_pos = state->gap_pos;
243 ret->completed = state->completed;
244 ret->movecount = state->movecount;
245
246 return ret;
247 }
248
249 void free_game(game_state *state)
250 {
251 sfree(state);
252 }
253
254 game_state *make_move(game_state *from, int x, int y, int button)
255 {
256 int gx, gy, dx, dy, ux, uy, up, p;
257 game_state *ret;
258
259 gx = X(from, from->gap_pos);
260 gy = Y(from, from->gap_pos);
261
262 if (button == CURSOR_RIGHT && gx > 0)
263 dx = gx - 1, dy = gy;
264 else if (button == CURSOR_LEFT && gx < from->w-1)
265 dx = gx + 1, dy = gy;
266 else if (button == CURSOR_DOWN && gy > 0)
267 dy = gy - 1, dx = gx;
268 else if (button == CURSOR_UP && gy < from->h-1)
269 dy = gy + 1, dx = gx;
270 else if (button == LEFT_BUTTON) {
271 dx = FROMCOORD(x);
272 dy = FROMCOORD(y);
273 if (dx < 0 || dx >= from->w || dy < 0 || dy >= from->h)
274 return NULL; /* out of bounds */
275 /*
276 * Any click location should be equal to the gap location
277 * in _precisely_ one coordinate.
278 */
279 if ((dx == gx && dy == gy) || (dx != gx && dy != gy))
280 return NULL;
281 } else
282 return NULL; /* no move */
283
284 /*
285 * Find the unit displacement from the original gap
286 * position towards this one.
287 */
288 ux = (dx < gx ? -1 : dx > gx ? +1 : 0);
289 uy = (dy < gy ? -1 : dy > gy ? +1 : 0);
290 up = C(from, ux, uy);
291
292 ret = dup_game(from);
293
294 ret->gap_pos = C(from, dx, dy);
295 assert(ret->gap_pos >= 0 && ret->gap_pos < ret->n);
296
297 ret->tiles[ret->gap_pos] = 0;
298
299 for (p = from->gap_pos; p != ret->gap_pos; p += up) {
300 assert(p >= 0 && p < from->n);
301 ret->tiles[p] = from->tiles[p + up];
302 ret->movecount++;
303 }
304
305 /*
306 * See if the game has been completed.
307 */
308 if (!ret->completed) {
309 ret->completed = ret->movecount;
310 for (p = 0; p < ret->n; p++)
311 if (ret->tiles[p] != (p < ret->n-1 ? p+1 : 0))
312 ret->completed = 0;
313 }
314
315 return ret;
316 }
317
318 /* ----------------------------------------------------------------------
319 * Drawing routines.
320 */
321
322 struct game_drawstate {
323 int started;
324 int w, h, bgcolour;
325 int *tiles;
326 };
327
328 void game_size(game_params *params, int *x, int *y)
329 {
330 *x = TILE_SIZE * params->w + 2 * BORDER;
331 *y = TILE_SIZE * params->h + 2 * BORDER;
332 }
333
334 float *game_colours(frontend *fe, game_state *state, int *ncolours)
335 {
336 float *ret = snewn(3 * NCOLOURS, float);
337 int i;
338 float max;
339
340 frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
341
342 /*
343 * Drop the background colour so that the highlight is
344 * noticeably brighter than it while still being under 1.
345 */
346 max = ret[COL_BACKGROUND*3];
347 for (i = 1; i < 3; i++)
348 if (ret[COL_BACKGROUND*3+i] > max)
349 max = ret[COL_BACKGROUND*3+i];
350 if (max * 1.2F > 1.0F) {
351 for (i = 0; i < 3; i++)
352 ret[COL_BACKGROUND*3+i] /= (max * 1.2F);
353 }
354
355 for (i = 0; i < 3; i++) {
356 ret[COL_HIGHLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 1.2F;
357 ret[COL_LOWLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 0.8F;
358 ret[COL_TEXT * 3 + i] = 0.0;
359 }
360
361 *ncolours = NCOLOURS;
362 return ret;
363 }
364
365 game_drawstate *game_new_drawstate(game_state *state)
366 {
367 struct game_drawstate *ds = snew(struct game_drawstate);
368 int i;
369
370 ds->started = FALSE;
371 ds->w = state->w;
372 ds->h = state->h;
373 ds->bgcolour = COL_BACKGROUND;
374 ds->tiles = snewn(ds->w*ds->h, int);
375 for (i = 0; i < ds->w*ds->h; i++)
376 ds->tiles[i] = -1;
377
378 return ds;
379 }
380
381 void game_free_drawstate(game_drawstate *ds)
382 {
383 sfree(ds->tiles);
384 sfree(ds);
385 }
386
387 static void draw_tile(frontend *fe, game_state *state, int x, int y,
388 int tile, int flash_colour)
389 {
390 if (tile == 0) {
391 draw_rect(fe, x, y, TILE_SIZE, TILE_SIZE,
392 flash_colour);
393 } else {
394 int coords[6];
395 char str[40];
396
397 coords[0] = x + TILE_SIZE - 1;
398 coords[1] = y + TILE_SIZE - 1;
399 coords[2] = x + TILE_SIZE - 1;
400 coords[3] = y;
401 coords[4] = x;
402 coords[5] = y + TILE_SIZE - 1;
403 draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
404 draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);
405
406 coords[0] = x;
407 coords[1] = y;
408 draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
409 draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);
410
411 draw_rect(fe, x + HIGHLIGHT_WIDTH, y + HIGHLIGHT_WIDTH,
412 TILE_SIZE - 2*HIGHLIGHT_WIDTH, TILE_SIZE - 2*HIGHLIGHT_WIDTH,
413 flash_colour);
414
415 sprintf(str, "%d", tile);
416 draw_text(fe, x + TILE_SIZE/2, y + TILE_SIZE/2,
417 FONT_VARIABLE, TILE_SIZE/3, ALIGN_VCENTRE | ALIGN_HCENTRE,
418 COL_TEXT, str);
419 }
420 draw_update(fe, x, y, TILE_SIZE, TILE_SIZE);
421 }
422
423 void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate,
424 game_state *state, float animtime, float flashtime)
425 {
426 int i, pass, bgcolour;
427
428 if (flashtime > 0) {
429 int frame = (int)(flashtime / FLASH_FRAME);
430 bgcolour = (frame % 2 ? COL_LOWLIGHT : COL_HIGHLIGHT);
431 } else
432 bgcolour = COL_BACKGROUND;
433
434 if (!ds->started) {
435 int coords[6];
436
437 draw_rect(fe, 0, 0,
438 TILE_SIZE * state->w + 2 * BORDER,
439 TILE_SIZE * state->h + 2 * BORDER, COL_BACKGROUND);
440 draw_update(fe, 0, 0,
441 TILE_SIZE * state->w + 2 * BORDER,
442 TILE_SIZE * state->h + 2 * BORDER);
443
444 /*
445 * Recessed area containing the whole puzzle.
446 */
447 coords[0] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
448 coords[1] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
449 coords[2] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
450 coords[3] = COORD(0) - HIGHLIGHT_WIDTH;
451 coords[4] = COORD(0) - HIGHLIGHT_WIDTH;
452 coords[5] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
453 draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
454 draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);
455
456 coords[1] = COORD(0) - HIGHLIGHT_WIDTH;
457 coords[0] = COORD(0) - HIGHLIGHT_WIDTH;
458 draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
459 draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);
460
461 ds->started = TRUE;
462 }
463
464 /*
465 * Now draw each tile. We do this in two passes to make
466 * animation easy.
467 */
468 for (pass = 0; pass < 2; pass++) {
469 for (i = 0; i < state->n; i++) {
470 int t, t0;
471 /*
472 * Figure out what should be displayed at this
473 * location. It's either a simple tile, or it's a
474 * transition between two tiles (in which case we say
475 * -1 because it must always be drawn).
476 */
477
478 if (oldstate && oldstate->tiles[i] != state->tiles[i])
479 t = -1;
480 else
481 t = state->tiles[i];
482
483 t0 = t;
484
485 if (ds->bgcolour != bgcolour || /* always redraw when flashing */
486 ds->tiles[i] != t || ds->tiles[i] == -1 || t == -1) {
487 int x, y;
488
489 /*
490 * Figure out what to _actually_ draw, and where to
491 * draw it.
492 */
493 if (t == -1) {
494 int x0, y0, x1, y1;
495 int j;
496
497 /*
498 * On the first pass, just blank the tile.
499 */
500 if (pass == 0) {
501 x = COORD(X(state, i));
502 y = COORD(Y(state, i));
503 t = 0;
504 } else {
505 float c;
506
507 t = state->tiles[i];
508
509 /*
510 * Don't bother moving the gap; just don't
511 * draw it.
512 */
513 if (t == 0)
514 continue;
515
516 /*
517 * Find the coordinates of this tile in the old and
518 * new states.
519 */
520 x1 = COORD(X(state, i));
521 y1 = COORD(Y(state, i));
522 for (j = 0; j < oldstate->n; j++)
523 if (oldstate->tiles[j] == state->tiles[i])
524 break;
525 assert(j < oldstate->n);
526 x0 = COORD(X(state, j));
527 y0 = COORD(Y(state, j));
528
529 c = (animtime / ANIM_TIME);
530 if (c < 0.0F) c = 0.0F;
531 if (c > 1.0F) c = 1.0F;
532
533 x = x0 + (int)(c * (x1 - x0));
534 y = y0 + (int)(c * (y1 - y0));
535 }
536
537 } else {
538 if (pass == 0)
539 continue;
540 x = COORD(X(state, i));
541 y = COORD(Y(state, i));
542 }
543
544 draw_tile(fe, state, x, y, t, bgcolour);
545 }
546 ds->tiles[i] = t0;
547 }
548 }
549 ds->bgcolour = bgcolour;
550
551 /*
552 * Update the status bar.
553 */
554 {
555 char statusbuf[256];
556
557 sprintf(statusbuf, "%sMoves: %d",
558 (state->completed ? "COMPLETED! " : ""),
559 (state->completed ? state->completed : state->movecount));
560
561 status_bar(fe, statusbuf);
562 }
563 }
564
565 float game_anim_length(game_state *oldstate, game_state *newstate)
566 {
567 return ANIM_TIME;
568 }
569
570 float game_flash_length(game_state *oldstate, game_state *newstate)
571 {
572 if (!oldstate->completed && newstate->completed)
573 return 2 * FLASH_FRAME;
574 else
575 return 0.0F;
576 }
577
578 int game_wants_statusbar(void)
579 {
580 return TRUE;
581 }
Simon Tatham's portable puzzles collection; import of svn://svn.tartarus.org/sgt/puzzles