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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; |
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45 | int movecount; |
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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 | |
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228 | state->completed = state->movecount = 0; |
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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; |
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244 | ret->movecount = state->movecount; |
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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]; |
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302 | ret->movecount++; |
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303 | } |
304 | |
305 | /* |
306 | * See if the game has been completed. |
307 | */ |
308 | if (!ret->completed) { |
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309 | ret->completed = ret->movecount; |
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310 | for (p = 0; p < ret->n; p++) |
311 | if (ret->tiles[p] != (p < ret->n-1 ? p+1 : 0)) |
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312 | ret->completed = 0; |
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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; |
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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 | } |
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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 | } |
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577 | |
578 | int game_wants_statusbar(void) |
579 | { |
580 | return TRUE; |
581 | } |