2 * fifteen.c: standard 15-puzzle.
13 const char *const game_name = "Fifteen";
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 0.1F
22 #define FLASH_FRAME 0.1F
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) )
47 game_params *default_params(void)
49 game_params *ret = snew(game_params);
56 int game_fetch_preset(int i, char **name, game_params **params)
61 void free_params(game_params *params)
66 game_params *dup_params(game_params *params)
68 game_params *ret = snew(game_params);
69 *ret = *params; /* structure copy */
73 int perm_parity(int *perm, int n)
79 for (i = 0; i < n-1; i++)
80 for (j = i+1; j < n; j++)
81 if (perm[i] > perm[j])
87 char *new_game_seed(game_params *params)
90 int x1, x2, p1, p2, parity;
95 n = params->w * params->h;
97 tiles = snewn(n, int);
100 for (i = 0; i < n; i++) {
110 * Place everything else except the last two tiles.
112 for (x = 0, i = n-1; i > 2; i--) {
113 int k = rand_upto(i);
116 for (j = 0; j < n; j++)
117 if (!used[j] && (k-- == 0))
120 assert(j < n && !used[j]);
123 while (tiles[x] >= 0)
130 * Find the last two locations, and the last two pieces.
132 while (tiles[x] >= 0)
137 while (tiles[x] >= 0)
142 for (i = 0; i < n; i++)
146 for (i = p1+1; i < n; i++)
152 * Determine the required parity of the overall permutation.
153 * This is the XOR of:
155 * - The chessboard parity ((x^y)&1) of the gap square. The
156 * bottom right, and therefore also the top left, count as
159 * - The parity of n. (The target permutation is 1,...,n-1,0
160 * rather than 0,...,n-1; this is a cyclic permutation of
161 * the starting point and hence is odd iff n is even.)
163 parity = (X(params, gap) ^ Y(params, gap) ^ (n+1)) & 1;
166 * Try the last two tiles one way round. If that fails, swap
171 if (perm_parity(tiles, n) != parity) {
174 assert(perm_parity(tiles, n) == parity);
178 * Now construct the game seed, by describing the tile array as
179 * a simple sequence of comma-separated integers.
183 for (i = 0; i < n; i++) {
187 k = sprintf(buf, "%d,", tiles[i]);
189 ret = sresize(ret, retlen + k + 1, char);
190 strcpy(ret + retlen, buf);
193 ret[retlen-1] = '\0'; /* delete last comma */
201 game_state *new_game(game_params *params, char *seed)
203 game_state *state = snew(game_state);
207 state->w = params->w;
208 state->h = params->h;
209 state->n = params->w * params->h;
210 state->tiles = snewn(state->n, int);
215 for (i = 0; i < state->n; i++) {
217 state->tiles[i] = atoi(p);
218 if (state->tiles[i] == 0)
220 while (*p && *p != ',')
222 if (*p) p++; /* eat comma */
225 assert(state->tiles[state->gap_pos] == 0);
227 state->completed = FALSE;
232 game_state *dup_game(game_state *state)
234 game_state *ret = snew(game_state);
239 ret->tiles = snewn(state->w * state->h, int);
240 memcpy(ret->tiles, state->tiles, state->w * state->h * sizeof(int));
241 ret->gap_pos = state->gap_pos;
242 ret->completed = state->completed;
247 void free_game(game_state *state)
252 game_state *make_move(game_state *from, int x, int y, int button)
254 int gx, gy, dx, dy, ux, uy, up, p;
257 gx = X(from, from->gap_pos);
258 gy = Y(from, from->gap_pos);
260 if (button == CURSOR_RIGHT && gx > 0)
261 dx = gx - 1, dy = gy;
262 else if (button == CURSOR_LEFT && gx < from->w-1)
263 dx = gx + 1, dy = gy;
264 else if (button == CURSOR_DOWN && gy > 0)
265 dy = gy - 1, dx = gx;
266 else if (button == CURSOR_UP && gy < from->h-1)
267 dy = gy + 1, dx = gx;
268 else if (button == LEFT_BUTTON) {
271 if (dx < 0 || dx >= from->w || dy < 0 || dy >= from->h)
272 return NULL; /* out of bounds */
274 * Any click location should be equal to the gap location
275 * in _precisely_ one coordinate.
277 if ((dx == gx && dy == gy) || (dx != gx && dy != gy))
280 return NULL; /* no move */
283 * Find the unit displacement from the original gap
284 * position towards this one.
286 ux = (dx < gx ? -1 : dx > gx ? +1 : 0);
287 uy = (dy < gy ? -1 : dy > gy ? +1 : 0);
288 up = C(from, ux, uy);
290 ret = dup_game(from);
292 ret->gap_pos = C(from, dx, dy);
293 assert(ret->gap_pos >= 0 && ret->gap_pos < ret->n);
295 ret->tiles[ret->gap_pos] = 0;
297 for (p = from->gap_pos; p != ret->gap_pos; p += up) {
298 assert(p >= 0 && p < from->n);
299 ret->tiles[p] = from->tiles[p + up];
303 * See if the game has been completed.
305 if (!ret->completed) {
306 ret->completed = TRUE;
307 for (p = 0; p < ret->n; p++)
308 if (ret->tiles[p] != (p < ret->n-1 ? p+1 : 0))
309 ret->completed = FALSE;
315 /* ----------------------------------------------------------------------
319 struct game_drawstate {
325 void game_size(game_params *params, int *x, int *y)
327 *x = TILE_SIZE * params->w + 2 * BORDER;
328 *y = TILE_SIZE * params->h + 2 * BORDER;
331 float *game_colours(frontend *fe, game_state *state, int *ncolours)
333 float *ret = snewn(3 * NCOLOURS, float);
337 frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
340 * Drop the background colour so that the highlight is
341 * noticeably brighter than it while still being under 1.
343 max = ret[COL_BACKGROUND*3];
344 for (i = 1; i < 3; i++)
345 if (ret[COL_BACKGROUND*3+i] > max)
346 max = ret[COL_BACKGROUND*3+i];
347 if (max * 1.2F > 1.0F) {
348 for (i = 0; i < 3; i++)
349 ret[COL_BACKGROUND*3+i] /= (max * 1.2F);
352 for (i = 0; i < 3; i++) {
353 ret[COL_HIGHLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 1.2F;
354 ret[COL_LOWLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 0.8F;
355 ret[COL_TEXT * 3 + i] = 0.0;
358 *ncolours = NCOLOURS;
362 game_drawstate *game_new_drawstate(game_state *state)
364 struct game_drawstate *ds = snew(struct game_drawstate);
370 ds->bgcolour = COL_BACKGROUND;
371 ds->tiles = snewn(ds->w*ds->h, int);
372 for (i = 0; i < ds->w*ds->h; i++)
378 void game_free_drawstate(game_drawstate *ds)
384 static void draw_tile(frontend *fe, game_state *state, int x, int y,
385 int tile, int flash_colour)
388 draw_rect(fe, x, y, TILE_SIZE, TILE_SIZE,
394 coords[0] = x + TILE_SIZE - 1;
395 coords[1] = y + TILE_SIZE - 1;
396 coords[2] = x + TILE_SIZE - 1;
399 coords[5] = y + TILE_SIZE - 1;
400 draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
401 draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);
405 draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
406 draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);
408 draw_rect(fe, x + HIGHLIGHT_WIDTH, y + HIGHLIGHT_WIDTH,
409 TILE_SIZE - 2*HIGHLIGHT_WIDTH, TILE_SIZE - 2*HIGHLIGHT_WIDTH,
412 sprintf(str, "%d", tile);
413 draw_text(fe, x + TILE_SIZE/2, y + TILE_SIZE/2,
414 FONT_VARIABLE, TILE_SIZE/3, ALIGN_VCENTRE | ALIGN_HCENTRE,
417 draw_update(fe, x, y, TILE_SIZE, TILE_SIZE);
420 void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate,
421 game_state *state, float animtime, float flashtime)
423 int i, pass, bgcolour;
426 int frame = (int)(flashtime / FLASH_FRAME);
427 bgcolour = (frame % 2 ? COL_LOWLIGHT : COL_HIGHLIGHT);
429 bgcolour = COL_BACKGROUND;
435 TILE_SIZE * state->w + 2 * BORDER,
436 TILE_SIZE * state->h + 2 * BORDER, COL_BACKGROUND);
437 draw_update(fe, 0, 0,
438 TILE_SIZE * state->w + 2 * BORDER,
439 TILE_SIZE * state->h + 2 * BORDER);
442 * Recessed area containing the whole puzzle.
444 coords[0] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
445 coords[1] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
446 coords[2] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
447 coords[3] = COORD(0) - HIGHLIGHT_WIDTH;
448 coords[4] = COORD(0) - HIGHLIGHT_WIDTH;
449 coords[5] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
450 draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
451 draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);
453 coords[1] = COORD(0) - HIGHLIGHT_WIDTH;
454 coords[0] = COORD(0) - HIGHLIGHT_WIDTH;
455 draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
456 draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);
462 * Now draw each tile. We do this in two passes to make
465 for (pass = 0; pass < 2; pass++) {
466 for (i = 0; i < state->n; i++) {
469 * Figure out what should be displayed at this
470 * location. It's either a simple tile, or it's a
471 * transition between two tiles (in which case we say
472 * -1 because it must always be drawn).
475 if (oldstate && oldstate->tiles[i] != state->tiles[i])
482 if (ds->bgcolour != bgcolour || /* always redraw when flashing */
483 ds->tiles[i] != t || ds->tiles[i] == -1 || t == -1) {
487 * Figure out what to _actually_ draw, and where to
495 * On the first pass, just blank the tile.
498 x = COORD(X(state, i));
499 y = COORD(Y(state, i));
507 * Don't bother moving the gap; just don't
514 * Find the coordinates of this tile in the old and
517 x1 = COORD(X(state, i));
518 y1 = COORD(Y(state, i));
519 for (j = 0; j < oldstate->n; j++)
520 if (oldstate->tiles[j] == state->tiles[i])
522 assert(j < oldstate->n);
523 x0 = COORD(X(state, j));
524 y0 = COORD(Y(state, j));
526 c = (animtime / ANIM_TIME);
527 if (c < 0.0F) c = 0.0F;
528 if (c > 1.0F) c = 1.0F;
530 x = x0 + (int)(c * (x1 - x0));
531 y = y0 + (int)(c * (y1 - y0));
537 x = COORD(X(state, i));
538 y = COORD(Y(state, i));
541 draw_tile(fe, state, x, y, t, bgcolour);
546 ds->bgcolour = bgcolour;
549 float game_anim_length(game_state *oldstate, game_state *newstate)
554 float game_flash_length(game_state *oldstate, game_state *newstate)
556 if (!oldstate->completed && newstate->completed)
557 return 2 * FLASH_FRAME;