2 * slide.c: Implementation of the block-sliding puzzle `Klotski'.
8 * - The dragging semantics are still subtly wrong in complex
11 * - Improve the generator.
12 * * actually, we seem to be mostly sensible already now. I
13 * want more choice over the type of main block and location
14 * of the exit/target, and I think I probably ought to give
15 * up on compactness and just bite the bullet and have the
16 * target area right outside the main wall, but mostly I
18 * * the move limit tends to make the game _slower_ to
19 * generate, which is odd. Perhaps investigate why.
21 * - Improve the graphics.
22 * * All the colours are a bit wishy-washy. _Some_ dark
23 * colours would surely not be excessive? Probably darken
24 * the tiles, the walls and the main block, and leave the
26 * * The cattle grid effect is still disgusting. Think of
27 * something completely different.
28 * * I think TRCIRC and BLCIRC should actually be drawn, as a
29 * pair of differently coloured octants. Haul out the
30 * Bresenham code, I suspect.
31 * * The highlight for next-piece-to-move in the solver is
32 * excessive, and the shadow blends in too well with the
33 * piece lowlights. Adjust both.
47 * The implementation of this game revolves around the insight
48 * which makes an exhaustive-search solver feasible: although
49 * there are many blocks which can be rearranged in many ways, any
50 * two blocks of the same shape are _indistinguishable_ and hence
51 * the number of _distinct_ board layouts is generally much
52 * smaller. So we adopt a representation for board layouts which
53 * is inherently canonical, i.e. there are no two distinct
54 * representations which encode indistinguishable layouts.
56 * The way we do this is to encode each square of the board, in
57 * the normal left-to-right top-to-bottom order, as being one of
58 * the following things:
59 * - the first square (in the given order) of a block (`anchor')
60 * - special case of the above: the anchor for the _main_ block
61 * (i.e. the one which the aim of the game is to get to the
63 * - a subsequent square of a block whose previous square was N
65 * - an impassable wall
67 * (We also separately store data about which board positions are
68 * forcefields only passable by the main block. We can't encode
69 * that in the main board data, because then the main block would
70 * destroy forcefields as it went over them.)
72 * Hence, for example, a 2x2 square block would be encoded as
73 * ANCHOR, followed by DIST(1), and w-2 squares later on there
74 * would be DIST(w-1) followed by DIST(1). So if you start at the
75 * last of those squares, the DIST numbers give you a linked list
76 * pointing back through all the other squares in the same block.
78 * So the solver simply does a bfs over all reachable positions,
79 * encoding them in this format and storing them in a tree234 to
80 * ensure it doesn't ever revisit an already-analysed position.
85 * The colours are arranged here so that every base colour is
86 * directly followed by its highlight colour and then its
87 * lowlight colour. Do not break this, or draw_tile() will get
94 COL_DRAGGING_HIGHLIGHT,
95 COL_DRAGGING_LOWLIGHT,
100 COL_MAIN_DRAGGING_HIGHLIGHT,
101 COL_MAIN_DRAGGING_LOWLIGHT,
103 COL_TARGET_HIGHLIGHT,
109 * Board layout is a simple array of bytes. Each byte holds:
111 #define ANCHOR 255 /* top-left-most square of some piece */
112 #define MAINANCHOR 254 /* anchor of _main_ piece */
113 #define EMPTY 253 /* empty square */
114 #define WALL 252 /* immovable wall */
116 /* all other values indicate distance back to previous square of same block */
117 #define ISDIST(x) ( (unsigned char)((x)-1) <= MAXDIST-1 )
119 #define ISANCHOR(x) ( (x)==ANCHOR || (x)==MAINANCHOR )
120 #define ISBLOCK(x) ( ISANCHOR(x) || ISDIST(x) )
123 * MAXDIST is the largest DIST value we can encode. This must
124 * therefore also be the maximum puzzle width in theory (although
125 * solver running time will dictate a much smaller limit in
128 #define MAXWID MAXDIST
135 struct game_immutable_state {
137 unsigned char *forcefield;
140 struct game_solution {
142 int *moves; /* just like from solve_board() */
148 unsigned char *board;
149 int tx, ty; /* target coords for MAINANCHOR */
150 int minmoves; /* for display only */
151 int lastmoved, lastmoved_pos; /* for move counting */
155 struct game_immutable_state *imm;
156 struct game_solution *soln;
160 static game_params *default_params(void)
162 game_params *ret = snew(game_params);
171 static const struct game_params slide_presets[] = {
177 static int game_fetch_preset(int i, char **name, game_params **params)
182 if (i < 0 || i >= lenof(slide_presets))
185 ret = snew(game_params);
186 *ret = slide_presets[i];
188 sprintf(str, "%dx%d", ret->w, ret->h);
189 if (ret->maxmoves >= 0)
190 sprintf(str + strlen(str), ", max %d moves", ret->maxmoves);
192 sprintf(str + strlen(str), ", no move limit");
199 static void free_params(game_params *params)
204 static game_params *dup_params(game_params *params)
206 game_params *ret = snew(game_params);
207 *ret = *params; /* structure copy */
211 static void decode_params(game_params *params, char const *string)
213 params->w = params->h = atoi(string);
214 while (*string && isdigit((unsigned char)*string)) string++;
215 if (*string == 'x') {
217 params->h = atoi(string);
218 while (*string && isdigit((unsigned char)*string)) string++;
220 if (*string == 'm') {
222 params->maxmoves = atoi(string);
223 while (*string && isdigit((unsigned char)*string)) string++;
224 } else if (*string == 'u') {
226 params->maxmoves = -1;
230 static char *encode_params(game_params *params, int full)
234 sprintf(data, "%dx%d", params->w, params->h);
235 if (params->maxmoves >= 0)
236 sprintf(data + strlen(data), "m%d", params->maxmoves);
238 sprintf(data + strlen(data), "u");
243 static config_item *game_configure(game_params *params)
248 ret = snewn(4, config_item);
250 ret[0].name = "Width";
251 ret[0].type = C_STRING;
252 sprintf(buf, "%d", params->w);
253 ret[0].sval = dupstr(buf);
256 ret[1].name = "Height";
257 ret[1].type = C_STRING;
258 sprintf(buf, "%d", params->h);
259 ret[1].sval = dupstr(buf);
262 ret[2].name = "Solution length limit";
263 ret[2].type = C_STRING;
264 sprintf(buf, "%d", params->maxmoves);
265 ret[2].sval = dupstr(buf);
276 static game_params *custom_params(config_item *cfg)
278 game_params *ret = snew(game_params);
280 ret->w = atoi(cfg[0].sval);
281 ret->h = atoi(cfg[1].sval);
282 ret->maxmoves = atoi(cfg[2].sval);
287 static char *validate_params(game_params *params, int full)
289 if (params->w > MAXWID)
290 return "Width must be at most " STR(MAXWID);
293 return "Width must be at least 5";
295 return "Height must be at least 4";
300 static char *board_text_format(int w, int h, unsigned char *data,
301 unsigned char *forcefield)
304 int *dsf = snew_dsf(wh);
306 int retpos, retlen = (w*2+2)*(h*2+1)+1;
307 char *ret = snewn(retlen, char);
309 for (i = 0; i < wh; i++)
311 dsf_merge(dsf, i - data[i], i);
313 for (y = 0; y < 2*h+1; y++) {
314 for (x = 0; x < 2*w+1; x++) {
316 int i = (y/2)*w+(x/2);
318 #define dtype(i) (ISBLOCK(data[i]) ? \
319 dsf_canonify(dsf, i) : data[i])
320 #define dchar(t) ((t)==EMPTY ? ' ' : (t)==WALL ? '#' : \
321 data[t] == MAINANCHOR ? '*' : '%')
323 if (y % 2 && x % 2) {
326 } else if (y % 2 && !(x % 2)) {
327 int j1 = (x > 0 ? dtype(i-1) : -1);
328 int j2 = (x < 2*w ? dtype(i) : -1);
333 } else if (!(y % 2) && (x % 2)) {
334 int j1 = (y > 0 ? dtype(i-w) : -1);
335 int j2 = (y < 2*h ? dtype(i) : -1);
341 int j1 = (x > 0 && y > 0 ? dtype(i-w-1) : -1);
342 int j2 = (x > 0 && y < 2*h ? dtype(i-1) : -1);
343 int j3 = (x < 2*w && y > 0 ? dtype(i-w) : -1);
344 int j4 = (x < 2*w && y < 2*h ? dtype(i) : -1);
345 if (j1 == j2 && j2 == j3 && j3 == j4)
347 else if (j1 == j2 && j3 == j4)
349 else if (j1 == j3 && j2 == j4)
355 assert(retpos < retlen);
358 assert(retpos < retlen);
359 ret[retpos++] = '\n';
361 assert(retpos < retlen);
362 ret[retpos++] = '\0';
363 assert(retpos == retlen);
368 /* ----------------------------------------------------------------------
373 * During solver execution, the set of visited board positions is
374 * stored as a tree234 of the following structures. `w', `h' and
375 * `data' are obvious in meaning; `dist' represents the minimum
376 * distance to reach this position from the starting point.
378 * `prev' links each board to the board position from which it was
379 * most efficiently derived.
388 static int boardcmp(void *av, void *bv)
390 struct board *a = (struct board *)av;
391 struct board *b = (struct board *)bv;
392 return memcmp(a->data, b->data, a->w * a->h);
395 static struct board *newboard(int w, int h, unsigned char *data)
397 struct board *b = malloc(sizeof(struct board) + w*h);
398 b->data = (unsigned char *)b + sizeof(struct board);
399 memcpy(b->data, data, w*h);
408 * The actual solver. Given a board, attempt to find the minimum
409 * length of move sequence which moves MAINANCHOR to (tx,ty), or
410 * -1 if no solution exists. Returns that minimum length.
412 * Also, if `moveout' is provided, writes out the moves in the
413 * form of a sequence of pairs of integers indicating the source
414 * and destination points of the anchor of the moved piece in each
415 * move. Exactly twice as many integers are written as the number
416 * returned from solve_board(), and `moveout' receives an int *
417 * which is a pointer to a dynamically allocated array.
419 static int solve_board(int w, int h, unsigned char *board,
420 unsigned char *forcefield, int tx, int ty,
421 int movelimit, int **moveout)
424 struct board *b, *b2, *b3;
425 int *next, *anchors, *which;
426 int *movereached, *movequeue, mqhead, mqtail;
427 tree234 *sorted, *queue;
432 #ifdef SOLVER_DIAGNOSTICS
434 char *t = board_text_format(w, h, board);
435 for (i = 0; i < h; i++) {
436 for (j = 0; j < w; j++) {
437 int c = board[i*w+j];
440 else if (c == MAINANCHOR)
442 else if (c == ANCHOR)
452 printf("Starting solver for:\n%s\n", t);
457 sorted = newtree234(boardcmp);
458 queue = newtree234(NULL);
460 b = newboard(w, h, board);
463 addpos234(queue, b, 0);
466 next = snewn(wh, int);
467 anchors = snewn(wh, int);
468 which = snewn(wh, int);
469 movereached = snewn(wh, int);
470 movequeue = snewn(wh, int);
473 while ((b = delpos234(queue, 0)) != NULL) {
475 if (movelimit >= 0 && b->dist >= movelimit) {
477 * The problem is not soluble in under `movelimit'
478 * moves, so we can quit right now.
483 if (b->dist != lastdist) {
484 #ifdef SOLVER_DIAGNOSTICS
485 printf("dist %d (%d)\n", b->dist, count234(sorted));
490 * Find all the anchors and form a linked list of the
491 * squares within each block.
493 for (i = 0; i < wh; i++) {
497 if (ISANCHOR(b->data[i])) {
500 } else if (ISDIST(b->data[i])) {
508 * For each anchor, do an array-based BFS to find all the
509 * places we can slide it to.
511 for (i = 0; i < wh; i++) {
516 for (j = 0; j < wh; j++)
517 movereached[j] = FALSE;
518 movequeue[mqtail++] = i;
519 while (mqhead < mqtail) {
520 int pos = movequeue[mqhead++];
523 * Try to move in each direction from here.
525 for (dir = 0; dir < 4; dir++) {
526 int dx = (dir == 0 ? -1 : dir == 1 ? +1 : 0);
527 int dy = (dir == 2 ? -1 : dir == 3 ? +1 : 0);
528 int offset = dy*w + dx;
529 int newpos = pos + offset;
533 * For each square involved in this block,
534 * check to see if the square d spaces away
535 * from it is either empty or part of the same
538 for (j = i; j >= 0; j = next[j]) {
539 int jy = (pos+j-i) / w + dy, jx = (pos+j-i) % w + dx;
540 if (jy >= 0 && jy < h && jx >= 0 && jx < w &&
541 ((b->data[j+d] == EMPTY || which[j+d] == i) &&
542 (b->data[i] == MAINANCHOR || !forcefield[j+d])))
548 continue; /* this direction wasn't feasible */
551 * If we've already tried moving this piece
554 if (movereached[newpos])
556 movereached[newpos] = TRUE;
557 movequeue[mqtail++] = newpos;
560 * We have a viable move. Make it.
562 b2 = newboard(w, h, b->data);
563 for (j = i; j >= 0; j = next[j])
565 for (j = i; j >= 0; j = next[j])
566 b2->data[j+d] = b->data[j];
568 b3 = add234(sorted, b2);
570 sfree(b2); /* we already got one */
572 b2->dist = b->dist + 1;
574 addpos234(queue, b2, qlen++);
575 if (b2->data[ty*w+tx] == MAINANCHOR)
576 goto done; /* search completed! */
590 * Now b2 represents the solved position. Backtrack to
591 * output the solution.
593 *moveout = snewn(ret * 2, int);
597 int from = -1, to = -1;
602 * Scan b and b2 to find out which piece has
605 for (i = 0; i < wh; i++) {
606 if (ISANCHOR(b->data[i]) && !ISANCHOR(b2->data[i])) {
609 } else if (!ISANCHOR(b->data[i]) && ISANCHOR(b2->data[i])){
615 assert(from >= 0 && to >= 0);
617 (*moveout)[--j] = to;
618 (*moveout)[--j] = from;
625 ret = -1; /* no solution */
632 while ((b = delpos234(sorted, 0)) != NULL)
645 /* ----------------------------------------------------------------------
646 * Random board generation.
649 static void generate_board(int w, int h, int *rtx, int *rty, int *minmoves,
650 random_state *rs, unsigned char **rboard,
651 unsigned char **rforcefield, int movelimit)
654 unsigned char *board, *board2, *forcefield;
655 unsigned char *tried_merge;
657 int *list, nlist, pos;
663 * Set up a board and fill it with singletons, except for a
666 board = snewn(wh, unsigned char);
667 forcefield = snewn(wh, unsigned char);
668 board2 = snewn(wh, unsigned char);
669 memset(board, ANCHOR, wh);
670 memset(forcefield, FALSE, wh);
671 for (i = 0; i < w; i++)
672 board[i] = board[i+w*(h-1)] = WALL;
673 for (i = 0; i < h; i++)
674 board[i*w] = board[i*w+(w-1)] = WALL;
676 tried_merge = snewn(wh * wh, unsigned char);
677 memset(tried_merge, 0, wh*wh);
681 * Invent a main piece at one extreme. (FIXME: vary the
682 * extreme, and the piece.)
684 board[w+1] = MAINANCHOR;
685 board[w+2] = DIST(1);
686 board[w*2+1] = DIST(w-1);
687 board[w*2+2] = DIST(1);
690 * Invent a target position. (FIXME: vary this too.)
694 forcefield[ty*w+tx+1] = forcefield[(ty+1)*w+tx+1] = TRUE;
695 board[ty*w+tx+1] = board[(ty+1)*w+tx+1] = EMPTY;
698 * Gradually remove singletons until the game becomes soluble.
700 for (j = w; j-- > 0 ;)
701 for (i = h; i-- > 0 ;)
702 if (board[i*w+j] == ANCHOR) {
704 * See if the board is already soluble.
706 if ((moves = solve_board(w, h, board, forcefield,
707 tx, ty, movelimit, NULL)) >= 0)
711 * Otherwise, remove this piece.
713 board[i*w+j] = EMPTY;
715 assert(!"We shouldn't get here");
719 * Make a list of all the inter-block edges on the board.
721 list = snewn(wh*2, int);
723 for (i = 0; i+1 < w; i++)
724 for (j = 0; j < h; j++)
725 list[nlist++] = (j*w+i) * 2 + 0; /* edge to the right of j*w+i */
726 for (j = 0; j+1 < h; j++)
727 for (i = 0; i < w; i++)
728 list[nlist++] = (j*w+i) * 2 + 1; /* edge below j*w+i */
731 * Now go through that list in random order, trying to merge
732 * the blocks on each side of each edge.
734 shuffle(list, nlist, sizeof(*list), rs);
740 y1 = y2 = pos / (w*2);
741 x1 = x2 = (pos / 2) % w;
750 * Immediately abandon the attempt if we've already tried
751 * to merge the same pair of blocks along a different
754 c1 = dsf_canonify(dsf, p1);
755 c2 = dsf_canonify(dsf, p2);
756 if (tried_merge[c1 * wh + c2])
760 * In order to be mergeable, these two squares must each
761 * either be, or belong to, a non-main anchor, and their
762 * anchors must also be distinct.
764 if (!ISBLOCK(board[p1]) || !ISBLOCK(board[p2]))
766 while (ISDIST(board[p1]))
768 while (ISDIST(board[p2]))
770 if (board[p1] == MAINANCHOR || board[p2] == MAINANCHOR || p1 == p2)
774 * We can merge these blocks. Try it, and see if the
775 * puzzle remains soluble.
777 memcpy(board2, board, wh);
779 while (p1 < wh || p2 < wh) {
781 * p1 and p2 are the squares at the head of each block
782 * list. Pick the smaller one and put it on the output
789 assert(i - j <= MAXDIST);
790 board[i] = DIST(i - j);
795 * Now advance whichever list that came from.
800 } while (p1 < wh && board[p1] != DIST(p1-i));
804 } while (p2 < wh && board[p2] != DIST(p2-i));
807 j = solve_board(w, h, board, forcefield, tx, ty, movelimit, NULL);
810 * Didn't work. Revert the merge.
812 memcpy(board, board2, wh);
813 tried_merge[c1 * wh + c2] = tried_merge[c2 * wh + c1] = TRUE;
819 dsf_merge(dsf, c1, c2);
820 c = dsf_canonify(dsf, c1);
821 for (i = 0; i < wh; i++)
822 tried_merge[c*wh+i] = (tried_merge[c1*wh+i] |
823 tried_merge[c2*wh+i]);
824 for (i = 0; i < wh; i++)
825 tried_merge[i*wh+c] = (tried_merge[i*wh+c1] |
826 tried_merge[i*wh+c2]);
835 *rforcefield = forcefield;
839 /* ----------------------------------------------------------------------
840 * End of solver/generator code.
843 static char *new_game_desc(game_params *params, random_state *rs,
844 char **aux, int interactive)
846 int w = params->w, h = params->h, wh = w*h;
847 int tx, ty, minmoves;
848 unsigned char *board, *forcefield;
852 generate_board(params->w, params->h, &tx, &ty, &minmoves, rs,
853 &board, &forcefield, params->maxmoves);
854 #ifdef GENERATOR_DIAGNOSTICS
856 char *t = board_text_format(params->w, params->h, board);
863 * Encode as a game ID.
865 ret = snewn(wh * 6 + 40, char);
869 if (ISDIST(board[i])) {
870 p += sprintf(p, "d%d", board[i]);
874 int b = board[i], f = forcefield[i];
875 int c = (b == ANCHOR ? 'a' :
876 b == MAINANCHOR ? 'm' :
878 /* b == WALL ? */ 'w');
882 while (i < wh && board[i] == b && forcefield[i] == f)
885 p += sprintf(p, "%d", count);
888 p += sprintf(p, ",%d,%d,%d", tx, ty, minmoves);
889 ret = sresize(ret, p+1 - ret, char);
897 static char *validate_desc(game_params *params, char *desc)
899 int w = params->w, h = params->h, wh = w*h;
901 int mains = 0, mpos = -1;
902 int i, tx, ty, minmoves;
905 active = snewn(wh, int);
906 link = snewn(wh, int);
909 while (*desc && *desc != ',') {
911 ret = "Too much data in game description";
916 if (*desc == 'f' || *desc == 'F') {
919 ret = "Expected another character after 'f' in game "
925 if (*desc == 'd' || *desc == 'D') {
929 if (!isdigit((unsigned char)*desc)) {
930 ret = "Expected a number after 'd' in game description";
934 while (*desc && isdigit((unsigned char)*desc)) desc++;
936 if (dist <= 0 || dist > i) {
937 ret = "Out-of-range number after 'd' in game description";
941 if (!active[i - dist]) {
942 ret = "Invalid back-reference in game description";
949 active[link[i]] = FALSE;
955 if (!strchr("aAmMeEwW", c)) {
956 ret = "Invalid character in game description";
959 if (isdigit((unsigned char)*desc)) {
961 while (*desc && isdigit((unsigned char)*desc)) desc++;
963 if (i + count > wh) {
964 ret = "Too much data in game description";
967 while (count-- > 0) {
968 active[i] = (strchr("aAmM", c) != NULL);
970 if (strchr("mM", c) != NULL) {
979 ret = (mains == 0 ? "No main piece specified in game description" :
980 "More than one main piece specified in game description");
984 ret = "Not enough data in game description";
989 * Now read the target coordinates.
991 i = sscanf(desc, ",%d,%d,%d", &tx, &ty, &minmoves);
993 ret = "No target coordinates specified";
996 * (but minmoves is optional)
1008 static game_state *new_game(midend *me, game_params *params, char *desc)
1010 int w = params->w, h = params->h, wh = w*h;
1014 state = snew(game_state);
1017 state->board = snewn(wh, unsigned char);
1018 state->lastmoved = state->lastmoved_pos = -1;
1019 state->movecount = 0;
1020 state->imm = snew(struct game_immutable_state);
1021 state->imm->refcount = 1;
1022 state->imm->forcefield = snewn(wh, unsigned char);
1026 while (*desc && *desc != ',') {
1037 if (*desc == 'd' || *desc == 'D') {
1042 while (*desc && isdigit((unsigned char)*desc)) desc++;
1044 state->board[i] = DIST(dist);
1045 state->imm->forcefield[i] = f;
1052 if (isdigit((unsigned char)*desc)) {
1054 while (*desc && isdigit((unsigned char)*desc)) desc++;
1056 assert(i + count <= wh);
1058 c = (c == 'a' || c == 'A' ? ANCHOR :
1059 c == 'm' || c == 'M' ? MAINANCHOR :
1060 c == 'e' || c == 'E' ? EMPTY :
1061 /* c == 'w' || c == 'W' ? */ WALL);
1063 while (count-- > 0) {
1064 state->board[i] = c;
1065 state->imm->forcefield[i] = f;
1072 * Now read the target coordinates.
1074 state->tx = state->ty = 0;
1075 state->minmoves = -1;
1076 i = sscanf(desc, ",%d,%d,%d", &state->tx, &state->ty, &state->minmoves);
1078 if (state->board[state->ty*w+state->tx] == MAINANCHOR)
1079 state->completed = 0; /* already complete! */
1081 state->completed = -1;
1083 state->cheated = FALSE;
1085 state->soln_index = -1;
1090 static game_state *dup_game(game_state *state)
1092 int w = state->w, h = state->h, wh = w*h;
1093 game_state *ret = snew(game_state);
1097 ret->board = snewn(wh, unsigned char);
1098 memcpy(ret->board, state->board, wh);
1099 ret->tx = state->tx;
1100 ret->ty = state->ty;
1101 ret->minmoves = state->minmoves;
1102 ret->lastmoved = state->lastmoved;
1103 ret->lastmoved_pos = state->lastmoved_pos;
1104 ret->movecount = state->movecount;
1105 ret->completed = state->completed;
1106 ret->cheated = state->cheated;
1107 ret->imm = state->imm;
1108 ret->imm->refcount++;
1109 ret->soln = state->soln;
1110 ret->soln_index = state->soln_index;
1112 ret->soln->refcount++;
1117 static void free_game(game_state *state)
1119 if (--state->imm->refcount <= 0) {
1120 sfree(state->imm->forcefield);
1123 if (state->soln && --state->soln->refcount <= 0) {
1124 sfree(state->soln->moves);
1127 sfree(state->board);
1131 static char *solve_game(game_state *state, game_state *currstate,
1132 char *aux, char **error)
1140 * Run the solver and attempt to find the shortest solution
1141 * from the current position.
1143 nmoves = solve_board(state->w, state->h, state->board,
1144 state->imm->forcefield, state->tx, state->ty,
1148 *error = "Unable to find a solution to this puzzle";
1152 *error = "Puzzle is already solved";
1157 * Encode the resulting solution as a move string.
1159 ret = snewn(nmoves * 40, char);
1163 for (i = 0; i < nmoves; i++) {
1164 p += sprintf(p, "%c%d-%d", sep, moves[i*2], moves[i*2+1]);
1169 assert(p - ret < nmoves * 40);
1170 ret = sresize(ret, p+1 - ret, char);
1175 static char *game_text_format(game_state *state)
1177 return board_text_format(state->w, state->h, state->board,
1178 state->imm->forcefield);
1184 int drag_offset_x, drag_offset_y;
1186 unsigned char *reachable;
1187 int *bfs_queue; /* used as scratch in interpret_move */
1190 static game_ui *new_ui(game_state *state)
1192 int w = state->w, h = state->h, wh = w*h;
1193 game_ui *ui = snew(game_ui);
1195 ui->dragging = FALSE;
1196 ui->drag_anchor = ui->drag_currpos = -1;
1197 ui->drag_offset_x = ui->drag_offset_y = -1;
1198 ui->reachable = snewn(wh, unsigned char);
1199 memset(ui->reachable, 0, wh);
1200 ui->bfs_queue = snewn(wh, int);
1205 static void free_ui(game_ui *ui)
1207 sfree(ui->bfs_queue);
1208 sfree(ui->reachable);
1212 static char *encode_ui(game_ui *ui)
1217 static void decode_ui(game_ui *ui, char *encoding)
1221 static void game_changed_state(game_ui *ui, game_state *oldstate,
1222 game_state *newstate)
1226 #define PREFERRED_TILESIZE 32
1227 #define TILESIZE (ds->tilesize)
1228 #define BORDER (TILESIZE/2)
1229 #define COORD(x) ( (x) * TILESIZE + BORDER )
1230 #define FROMCOORD(x) ( ((x) - BORDER + TILESIZE) / TILESIZE - 1 )
1231 #define BORDER_WIDTH (1 + TILESIZE/20)
1232 #define HIGHLIGHT_WIDTH (1 + TILESIZE/16)
1234 #define FLASH_INTERVAL 0.10F
1235 #define FLASH_TIME 3*FLASH_INTERVAL
1237 struct game_drawstate {
1240 unsigned long *grid; /* what's currently displayed */
1244 static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds,
1245 int x, int y, int button)
1247 int w = state->w, h = state->h, wh = w*h;
1251 if (button == LEFT_BUTTON) {
1255 if (tx < 0 || tx >= w || ty < 0 || ty >= h ||
1256 !ISBLOCK(state->board[ty*w+tx]))
1257 return NULL; /* this click has no effect */
1260 * User has clicked on a block. Find the block's anchor
1261 * and register that we've started dragging it.
1264 while (ISDIST(state->board[i]))
1265 i -= state->board[i];
1266 assert(i >= 0 && i < wh);
1268 ui->dragging = TRUE;
1269 ui->drag_anchor = i;
1270 ui->drag_offset_x = tx - (i % w);
1271 ui->drag_offset_y = ty - (i / w);
1272 ui->drag_currpos = i;
1275 * Now we immediately bfs out from the current location of
1276 * the anchor, to find all the places to which this block
1279 memset(ui->reachable, FALSE, wh);
1281 ui->reachable[i] = TRUE;
1282 ui->bfs_queue[qtail++] = i;
1283 for (j = i; j < wh; j++)
1284 if (state->board[j] == DIST(j - i))
1286 while (qhead < qtail) {
1287 int pos = ui->bfs_queue[qhead++];
1288 int x = pos % w, y = pos / w;
1291 for (dir = 0; dir < 4; dir++) {
1292 int dx = (dir == 0 ? -1 : dir == 1 ? +1 : 0);
1293 int dy = (dir == 2 ? -1 : dir == 3 ? +1 : 0);
1296 if (x + dx < 0 || x + dx >= w ||
1297 y + dy < 0 || y + dy >= h)
1300 newpos = pos + dy*w + dx;
1301 if (ui->reachable[newpos])
1302 continue; /* already done this one */
1305 * Now search the grid to see if the block we're
1306 * dragging could fit into this space.
1308 for (j = i; j >= 0; j = (ISDIST(state->board[j]) ?
1309 j - state->board[j] : -1)) {
1310 int jx = (j+pos-ui->drag_anchor) % w;
1311 int jy = (j+pos-ui->drag_anchor) / w;
1314 if (jx + dx < 0 || jx + dx >= w ||
1315 jy + dy < 0 || jy + dy >= h)
1316 break; /* this position isn't valid at all */
1318 j2 = (j+pos-ui->drag_anchor) + dy*w + dx;
1320 if (state->board[j2] == EMPTY &&
1321 (!state->imm->forcefield[j2] ||
1322 state->board[ui->drag_anchor] == MAINANCHOR))
1324 while (ISDIST(state->board[j2]))
1325 j2 -= state->board[j2];
1326 assert(j2 >= 0 && j2 < wh);
1327 if (j2 == ui->drag_anchor)
1335 * If we got to the end of that loop without
1336 * disqualifying this position, mark it as
1337 * reachable for this drag.
1339 ui->reachable[newpos] = TRUE;
1340 ui->bfs_queue[qtail++] = newpos;
1346 * And that's it. Update the display to reflect the start
1350 } else if (button == LEFT_DRAG && ui->dragging) {
1354 tx -= ui->drag_offset_x;
1355 ty -= ui->drag_offset_y;
1356 if (tx < 0 || tx >= w || ty < 0 || ty >= h ||
1357 !ui->reachable[ty*w+tx])
1358 return NULL; /* this drag has no effect */
1360 ui->drag_currpos = ty*w+tx;
1362 } else if (button == LEFT_RELEASE && ui->dragging) {
1363 char data[256], *str;
1366 * Terminate the drag, and if the piece has actually moved
1367 * then return a move string quoting the old and new
1368 * locations of the piece's anchor.
1370 if (ui->drag_anchor != ui->drag_currpos) {
1371 sprintf(data, "M%d-%d", ui->drag_anchor, ui->drag_currpos);
1374 str = ""; /* null move; just update the UI */
1376 ui->dragging = FALSE;
1377 ui->drag_anchor = ui->drag_currpos = -1;
1378 ui->drag_offset_x = ui->drag_offset_y = -1;
1379 memset(ui->reachable, 0, wh);
1382 } else if (button == ' ' && state->soln) {
1384 * Make the next move in the stored solution.
1389 a1 = state->soln->moves[state->soln_index*2];
1390 a2 = state->soln->moves[state->soln_index*2+1];
1391 if (a1 == state->lastmoved_pos)
1392 a1 = state->lastmoved;
1394 sprintf(data, "M%d-%d", a1, a2);
1395 return dupstr(data);
1401 static int move_piece(int w, int h, const unsigned char *src,
1402 unsigned char *dst, unsigned char *ff, int from, int to)
1407 if (!ISANCHOR(dst[from]))
1411 * Scan to the far end of the piece's linked list.
1413 for (i = j = from; j < wh; j++)
1414 if (src[j] == DIST(j - i))
1418 * Remove the piece from its old location in the new
1421 for (j = i; j >= 0; j = (ISDIST(src[j]) ? j - src[j] : -1))
1425 * And put it back in at the new location.
1427 for (j = i; j >= 0; j = (ISDIST(src[j]) ? j - src[j] : -1)) {
1428 int jn = j + to - from;
1429 if (jn < 0 || jn >= wh)
1431 if (dst[jn] == EMPTY && (!ff[jn] || src[from] == MAINANCHOR)) {
1441 static game_state *execute_move(game_state *state, char *move)
1443 int w = state->w, h = state->h /* , wh = w*h */;
1445 int a1, a2, n, movesize;
1446 game_state *ret = dup_game(state);
1452 * This is a solve move, so we just set up a stored
1455 if (ret->soln && --ret->soln->refcount <= 0) {
1456 sfree(ret->soln->moves);
1459 ret->soln = snew(struct game_solution);
1460 ret->soln->nmoves = 0;
1461 ret->soln->moves = NULL;
1462 ret->soln->refcount = 1;
1463 ret->soln_index = 0;
1464 ret->cheated = TRUE;
1469 if (sscanf(move, "%d-%d%n", &a1, &a2, &n) != 2) {
1475 * Special case: if the first move in the solution
1476 * involves the piece for which we already have a
1477 * partial stored move, adjust the source point to
1478 * the original starting point of that piece.
1480 if (ret->soln->nmoves == 0 && a1 == ret->lastmoved)
1481 a1 = ret->lastmoved_pos;
1483 if (ret->soln->nmoves >= movesize) {
1484 movesize = (ret->soln->nmoves + 48) * 4 / 3;
1485 ret->soln->moves = sresize(ret->soln->moves,
1489 ret->soln->moves[2*ret->soln->nmoves] = a1;
1490 ret->soln->moves[2*ret->soln->nmoves+1] = a2;
1491 ret->soln->nmoves++;
1495 move++; /* eat comma */
1497 } else if (c == 'M') {
1499 if (sscanf(move, "%d-%d%n", &a1, &a2, &n) != 2 ||
1500 !move_piece(w, h, state->board, ret->board,
1501 state->imm->forcefield, a1, a2)) {
1505 if (a1 == ret->lastmoved) {
1507 * If the player has moved the same piece as they
1508 * moved last time, don't increment the move
1509 * count. In fact, if they've put the piece back
1510 * where it started from, _decrement_ the move
1513 if (a2 == ret->lastmoved_pos) {
1514 ret->movecount--; /* reverted last move */
1515 ret->lastmoved = ret->lastmoved_pos = -1;
1517 ret->lastmoved = a2;
1518 /* don't change lastmoved_pos */
1521 ret->lastmoved = a2;
1522 ret->lastmoved_pos = a1;
1527 * If we have a stored solution path, see if we've
1528 * strayed from it or successfully made the next move
1531 if (ret->soln && ret->lastmoved_pos >= 0) {
1532 if (ret->lastmoved_pos !=
1533 ret->soln->moves[ret->soln_index*2]) {
1534 /* strayed from the path */
1535 ret->soln->refcount--;
1536 assert(ret->soln->refcount > 0);
1537 /* `state' at least still exists */
1539 ret->soln_index = -1;
1540 } else if (ret->lastmoved ==
1541 ret->soln->moves[ret->soln_index*2+1]) {
1542 /* advanced along the path */
1544 if (ret->soln_index >= ret->soln->nmoves) {
1545 /* finished the path! */
1546 ret->soln->refcount--;
1547 assert(ret->soln->refcount > 0);
1548 /* `state' at least still exists */
1550 ret->soln_index = -1;
1555 if (ret->board[a2] == MAINANCHOR &&
1556 a2 == ret->ty * w + ret->tx && ret->completed < 0)
1557 ret->completed = ret->movecount;
1574 /* ----------------------------------------------------------------------
1578 static void game_compute_size(game_params *params, int tilesize,
1581 /* fool the macros */
1582 struct dummy { int tilesize; } dummy = { tilesize }, *ds = &dummy;
1584 *x = params->w * TILESIZE + 2*BORDER;
1585 *y = params->h * TILESIZE + 2*BORDER;
1588 static void game_set_size(drawing *dr, game_drawstate *ds,
1589 game_params *params, int tilesize)
1591 ds->tilesize = tilesize;
1594 static void raise_colour(float *target, float *src, float *limit)
1597 for (i = 0; i < 3; i++)
1598 target[i] = (2*src[i] + limit[i]) / 3;
1601 static float *game_colours(frontend *fe, int *ncolours)
1603 float *ret = snewn(3 * NCOLOURS, float);
1605 game_mkhighlight(fe, ret, COL_BACKGROUND, COL_HIGHLIGHT, COL_LOWLIGHT);
1608 * When dragging a tile, we light it up a bit.
1610 raise_colour(ret+3*COL_DRAGGING,
1611 ret+3*COL_BACKGROUND, ret+3*COL_HIGHLIGHT);
1612 raise_colour(ret+3*COL_DRAGGING_HIGHLIGHT,
1613 ret+3*COL_HIGHLIGHT, ret+3*COL_HIGHLIGHT);
1614 raise_colour(ret+3*COL_DRAGGING_LOWLIGHT,
1615 ret+3*COL_LOWLIGHT, ret+3*COL_HIGHLIGHT);
1618 * The main tile is tinted blue.
1620 ret[COL_MAIN * 3 + 0] = ret[COL_BACKGROUND * 3 + 0];
1621 ret[COL_MAIN * 3 + 1] = ret[COL_BACKGROUND * 3 + 1];
1622 ret[COL_MAIN * 3 + 2] = ret[COL_HIGHLIGHT * 3 + 2];
1623 game_mkhighlight_specific(fe, ret, COL_MAIN,
1624 COL_MAIN_HIGHLIGHT, COL_MAIN_LOWLIGHT);
1627 * And we light that up a bit too when dragging.
1629 raise_colour(ret+3*COL_MAIN_DRAGGING,
1630 ret+3*COL_MAIN, ret+3*COL_MAIN_HIGHLIGHT);
1631 raise_colour(ret+3*COL_MAIN_DRAGGING_HIGHLIGHT,
1632 ret+3*COL_MAIN_HIGHLIGHT, ret+3*COL_MAIN_HIGHLIGHT);
1633 raise_colour(ret+3*COL_MAIN_DRAGGING_LOWLIGHT,
1634 ret+3*COL_MAIN_LOWLIGHT, ret+3*COL_MAIN_HIGHLIGHT);
1637 * The target area on the floor is tinted green.
1639 ret[COL_TARGET * 3 + 0] = ret[COL_BACKGROUND * 3 + 0];
1640 ret[COL_TARGET * 3 + 1] = ret[COL_HIGHLIGHT * 3 + 1];
1641 ret[COL_TARGET * 3 + 2] = ret[COL_BACKGROUND * 3 + 2];
1642 game_mkhighlight_specific(fe, ret, COL_TARGET,
1643 COL_TARGET_HIGHLIGHT, COL_TARGET_LOWLIGHT);
1645 *ncolours = NCOLOURS;
1649 static game_drawstate *game_new_drawstate(drawing *dr, game_state *state)
1651 int w = state->w, h = state->h, wh = w*h;
1652 struct game_drawstate *ds = snew(struct game_drawstate);
1658 ds->started = FALSE;
1659 ds->grid = snewn(wh, unsigned long);
1660 for (i = 0; i < wh; i++)
1661 ds->grid[i] = ~(unsigned long)0;
1666 static void game_free_drawstate(drawing *dr, game_drawstate *ds)
1672 #define BG_NORMAL 0x00000001UL
1673 #define BG_TARGET 0x00000002UL
1674 #define BG_FORCEFIELD 0x00000004UL
1675 #define FLASH_LOW 0x00000008UL
1676 #define FLASH_HIGH 0x00000010UL
1677 #define FG_WALL 0x00000020UL
1678 #define FG_MAIN 0x00000040UL
1679 #define FG_NORMAL 0x00000080UL
1680 #define FG_DRAGGING 0x00000100UL
1681 #define FG_SHADOW 0x00000200UL
1682 #define FG_SOLVEPIECE 0x00000400UL
1683 #define FG_MAINPIECESH 11
1684 #define FG_SHADOWSH 19
1686 #define PIECE_LBORDER 0x00000001UL
1687 #define PIECE_TBORDER 0x00000002UL
1688 #define PIECE_RBORDER 0x00000004UL
1689 #define PIECE_BBORDER 0x00000008UL
1690 #define PIECE_TLCORNER 0x00000010UL
1691 #define PIECE_TRCORNER 0x00000020UL
1692 #define PIECE_BLCORNER 0x00000040UL
1693 #define PIECE_BRCORNER 0x00000080UL
1694 #define PIECE_MASK 0x000000FFUL
1699 #define TYPE_MASK 0xF000
1700 #define COL_MASK 0x0FFF
1701 #define TYPE_RECT 0x0000
1702 #define TYPE_TLCIRC 0x4000
1703 #define TYPE_TRCIRC 0x5000
1704 #define TYPE_BLCIRC 0x6000
1705 #define TYPE_BRCIRC 0x7000
1706 static void maybe_rect(drawing *dr, int x, int y, int w, int h, int coltype)
1708 int colour = coltype & COL_MASK, type = coltype & TYPE_MASK;
1710 if (colour > NCOLOURS)
1712 if (type == TYPE_RECT) {
1713 draw_rect(dr, x, y, w, h, colour);
1717 clip(dr, x, y, w, h);
1727 draw_circle(dr, cx, cy, r, colour, colour);
1733 static void draw_wallpart(drawing *dr, game_drawstate *ds,
1734 int tx, int ty, unsigned long val,
1735 int cl, int cc, int ch)
1737 draw_rect(dr, tx, ty, TILESIZE, TILESIZE, cc);
1738 if (val & PIECE_LBORDER)
1739 draw_rect(dr, tx, ty, HIGHLIGHT_WIDTH, TILESIZE,
1741 if (val & PIECE_RBORDER)
1742 draw_rect(dr, tx+TILESIZE-HIGHLIGHT_WIDTH, ty,
1743 HIGHLIGHT_WIDTH, TILESIZE, cl);
1744 if (val & PIECE_TBORDER)
1745 draw_rect(dr, tx, ty, TILESIZE, HIGHLIGHT_WIDTH, ch);
1746 if (val & PIECE_BBORDER)
1747 draw_rect(dr, tx, ty+TILESIZE-HIGHLIGHT_WIDTH,
1748 TILESIZE, HIGHLIGHT_WIDTH, cl);
1749 if (!((PIECE_BBORDER | PIECE_LBORDER) &~ val))
1750 draw_rect(dr, tx, ty+TILESIZE-HIGHLIGHT_WIDTH,
1751 HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH, cc);
1752 if (!((PIECE_TBORDER | PIECE_RBORDER) &~ val))
1753 draw_rect(dr, tx+TILESIZE-HIGHLIGHT_WIDTH, ty,
1754 HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH, cc);
1755 if (val & PIECE_TLCORNER)
1756 draw_rect(dr, tx, ty, HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH, ch);
1757 if (val & PIECE_BRCORNER)
1758 draw_rect(dr, tx+TILESIZE-HIGHLIGHT_WIDTH,
1759 ty+TILESIZE-HIGHLIGHT_WIDTH,
1760 HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH, cl);
1763 static void draw_piecepart(drawing *dr, game_drawstate *ds,
1764 int tx, int ty, unsigned long val,
1765 int cl, int cc, int ch)
1770 * Drawing the blocks is hellishly fiddly. The blocks don't
1771 * stretch to the full size of the tile; there's a border
1772 * around them of size BORDER_WIDTH. Then they have bevelled
1773 * borders of size HIGHLIGHT_WIDTH, and also rounded corners.
1775 * I tried for some time to find a clean and clever way to
1776 * figure out what needed drawing from the corner and border
1777 * flags, but in the end the cleanest way I could find was the
1778 * following. We divide the grid square into 25 parts by
1779 * ruling four horizontal and four vertical lines across it;
1780 * those lines are at BORDER_WIDTH and BORDER_WIDTH +
1781 * HIGHLIGHT_WIDTH from the top, from the bottom, from the
1782 * left and from the right. Then we carefully consider each of
1783 * the resulting 25 sections of square, and decide separately
1784 * what needs to go in it based on the flags. In complicated
1785 * cases there can be up to five possibilities affecting any
1786 * given section (no corner or border flags, just the corner
1787 * flag, one border flag, the other border flag, both border
1788 * flags). So there's a lot of very fiddly logic here and all
1789 * I could really think to do was give it my best shot and
1790 * then test it and correct all the typos. Not fun to write,
1791 * and I'm sure it isn't fun to read either, but it seems to
1796 x[1] = x[0] + BORDER_WIDTH;
1797 x[2] = x[1] + HIGHLIGHT_WIDTH;
1798 x[5] = tx + TILESIZE;
1799 x[4] = x[5] - BORDER_WIDTH;
1800 x[3] = x[4] - HIGHLIGHT_WIDTH;
1803 y[1] = y[0] + BORDER_WIDTH;
1804 y[2] = y[1] + HIGHLIGHT_WIDTH;
1805 y[5] = ty + TILESIZE;
1806 y[4] = y[5] - BORDER_WIDTH;
1807 y[3] = y[4] - HIGHLIGHT_WIDTH;
1809 #define RECT(p,q) x[p], y[q], x[(p)+1]-x[p], y[(q)+1]-y[q]
1811 maybe_rect(dr, RECT(0,0),
1812 (val & (PIECE_TLCORNER | PIECE_TBORDER |
1813 PIECE_LBORDER)) ? -1 : cc);
1814 maybe_rect(dr, RECT(1,0),
1815 (val & PIECE_TLCORNER) ? ch : (val & PIECE_TBORDER) ? -1 :
1816 (val & PIECE_LBORDER) ? ch : cc);
1817 maybe_rect(dr, RECT(2,0),
1818 (val & PIECE_TBORDER) ? -1 : cc);
1819 maybe_rect(dr, RECT(3,0),
1820 (val & PIECE_TRCORNER) ? cl : (val & PIECE_TBORDER) ? -1 :
1821 (val & PIECE_RBORDER) ? cl : cc);
1822 maybe_rect(dr, RECT(4,0),
1823 (val & (PIECE_TRCORNER | PIECE_TBORDER |
1824 PIECE_RBORDER)) ? -1 : cc);
1825 maybe_rect(dr, RECT(0,1),
1826 (val & PIECE_TLCORNER) ? ch : (val & PIECE_LBORDER) ? -1 :
1827 (val & PIECE_TBORDER) ? ch : cc);
1828 maybe_rect(dr, RECT(1,1),
1829 (val & PIECE_TLCORNER) ? cc : -1);
1830 maybe_rect(dr, RECT(1,1),
1831 (val & PIECE_TLCORNER) ? ch | TYPE_TLCIRC :
1832 !((PIECE_TBORDER | PIECE_LBORDER) &~ val) ? ch | TYPE_BRCIRC :
1833 (val & (PIECE_TBORDER | PIECE_LBORDER)) ? ch : cc);
1834 maybe_rect(dr, RECT(2,1),
1835 (val & PIECE_TBORDER) ? ch : cc);
1836 maybe_rect(dr, RECT(3,1),
1837 (val & (PIECE_TBORDER | PIECE_RBORDER)) == PIECE_TBORDER ? ch :
1838 (val & (PIECE_TBORDER | PIECE_RBORDER)) == PIECE_RBORDER ? cl :
1839 !((PIECE_TBORDER|PIECE_RBORDER) &~ val) ? cc | TYPE_BLCIRC :
1841 maybe_rect(dr, RECT(4,1),
1842 (val & PIECE_TRCORNER) ? ch : (val & PIECE_RBORDER) ? -1 :
1843 (val & PIECE_TBORDER) ? ch : cc);
1844 maybe_rect(dr, RECT(0,2),
1845 (val & PIECE_LBORDER) ? -1 : cc);
1846 maybe_rect(dr, RECT(1,2),
1847 (val & PIECE_LBORDER) ? ch : cc);
1848 maybe_rect(dr, RECT(2,2),
1850 maybe_rect(dr, RECT(3,2),
1851 (val & PIECE_RBORDER) ? cl : cc);
1852 maybe_rect(dr, RECT(4,2),
1853 (val & PIECE_RBORDER) ? -1 : cc);
1854 maybe_rect(dr, RECT(0,3),
1855 (val & PIECE_BLCORNER) ? cl : (val & PIECE_LBORDER) ? -1 :
1856 (val & PIECE_BBORDER) ? cl : cc);
1857 maybe_rect(dr, RECT(1,3),
1858 (val & (PIECE_BBORDER | PIECE_LBORDER)) == PIECE_BBORDER ? cl :
1859 (val & (PIECE_BBORDER | PIECE_LBORDER)) == PIECE_LBORDER ? ch :
1860 !((PIECE_BBORDER|PIECE_LBORDER) &~ val) ? cc | TYPE_TRCIRC :
1862 maybe_rect(dr, RECT(2,3),
1863 (val & PIECE_BBORDER) ? cl : cc);
1864 maybe_rect(dr, RECT(3,3),
1865 (val & PIECE_BRCORNER) ? cc : -1);
1866 maybe_rect(dr, RECT(3,3),
1867 (val & PIECE_BRCORNER) ? cl | TYPE_BRCIRC :
1868 !((PIECE_BBORDER | PIECE_RBORDER) &~ val) ? cl | TYPE_TLCIRC :
1869 (val & (PIECE_BBORDER | PIECE_RBORDER)) ? cl : cc);
1870 maybe_rect(dr, RECT(4,3),
1871 (val & PIECE_BRCORNER) ? cl : (val & PIECE_RBORDER) ? -1 :
1872 (val & PIECE_BBORDER) ? cl : cc);
1873 maybe_rect(dr, RECT(0,4),
1874 (val & (PIECE_BLCORNER | PIECE_BBORDER | PIECE_LBORDER)) ? -1 : cc);
1875 maybe_rect(dr, RECT(1,4),
1876 (val & PIECE_BLCORNER) ? ch : (val & PIECE_BBORDER) ? -1 :
1877 (val & PIECE_LBORDER) ? ch : cc);
1878 maybe_rect(dr, RECT(2,4),
1879 (val & PIECE_BBORDER) ? -1 : cc);
1880 maybe_rect(dr, RECT(3,4),
1881 (val & PIECE_BRCORNER) ? cl : (val & PIECE_BBORDER) ? -1 :
1882 (val & PIECE_RBORDER) ? cl : cc);
1883 maybe_rect(dr, RECT(4,4),
1884 (val & (PIECE_BRCORNER | PIECE_BBORDER |
1885 PIECE_RBORDER)) ? -1 : cc);
1890 static void draw_tile(drawing *dr, game_drawstate *ds,
1891 int x, int y, unsigned long val)
1893 int tx = COORD(x), ty = COORD(y);
1897 * Draw the tile background.
1899 if (val & BG_TARGET)
1902 cc = COL_BACKGROUND;
1905 if (val & FLASH_LOW)
1907 else if (val & FLASH_HIGH)
1910 draw_rect(dr, tx, ty, TILESIZE, TILESIZE, cc);
1911 if (val & BG_FORCEFIELD) {
1913 * Cattle-grid effect to indicate that nothing but the
1914 * main block can slide over this square.
1916 int n = 3 * (TILESIZE / (3*HIGHLIGHT_WIDTH));
1919 for (i = 1; i < n; i += 3) {
1920 draw_rect(dr, tx,ty+(TILESIZE*i/n), TILESIZE,HIGHLIGHT_WIDTH, cl);
1921 draw_rect(dr, tx+(TILESIZE*i/n),ty, HIGHLIGHT_WIDTH,TILESIZE, cl);
1926 * Draw the tile midground: a shadow of a block, for
1927 * displaying partial solutions.
1929 if (val & FG_SHADOW) {
1930 draw_piecepart(dr, ds, tx, ty, (val >> FG_SHADOWSH) & PIECE_MASK,
1935 * Draw the tile foreground, i.e. some section of a block or
1938 if (val & FG_WALL) {
1939 cc = COL_BACKGROUND;
1942 if (val & FLASH_LOW)
1944 else if (val & FLASH_HIGH)
1947 draw_wallpart(dr, ds, tx, ty, (val >> FG_MAINPIECESH) & PIECE_MASK,
1949 } else if (val & (FG_MAIN | FG_NORMAL)) {
1950 if (val & FG_DRAGGING)
1951 cc = (val & FG_MAIN ? COL_MAIN_DRAGGING : COL_DRAGGING);
1953 cc = (val & FG_MAIN ? COL_MAIN : COL_BACKGROUND);
1957 if (val & FLASH_LOW)
1959 else if (val & (FLASH_HIGH | FG_SOLVEPIECE))
1962 draw_piecepart(dr, ds, tx, ty, (val >> FG_MAINPIECESH) & PIECE_MASK,
1966 draw_update(dr, tx, ty, TILESIZE, TILESIZE);
1969 static unsigned long find_piecepart(int w, int h, int *dsf, int x, int y)
1972 int canon = dsf_canonify(dsf, i);
1973 unsigned long val = 0;
1975 if (x == 0 || canon != dsf_canonify(dsf, i-1))
1976 val |= PIECE_LBORDER;
1977 if (y== 0 || canon != dsf_canonify(dsf, i-w))
1978 val |= PIECE_TBORDER;
1979 if (x == w-1 || canon != dsf_canonify(dsf, i+1))
1980 val |= PIECE_RBORDER;
1981 if (y == h-1 || canon != dsf_canonify(dsf, i+w))
1982 val |= PIECE_BBORDER;
1983 if (!(val & (PIECE_TBORDER | PIECE_LBORDER)) &&
1984 canon != dsf_canonify(dsf, i-1-w))
1985 val |= PIECE_TLCORNER;
1986 if (!(val & (PIECE_TBORDER | PIECE_RBORDER)) &&
1987 canon != dsf_canonify(dsf, i+1-w))
1988 val |= PIECE_TRCORNER;
1989 if (!(val & (PIECE_BBORDER | PIECE_LBORDER)) &&
1990 canon != dsf_canonify(dsf, i-1+w))
1991 val |= PIECE_BLCORNER;
1992 if (!(val & (PIECE_BBORDER | PIECE_RBORDER)) &&
1993 canon != dsf_canonify(dsf, i+1+w))
1994 val |= PIECE_BRCORNER;
1998 static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate,
1999 game_state *state, int dir, game_ui *ui,
2000 float animtime, float flashtime)
2002 int w = state->w, h = state->h, wh = w*h;
2003 unsigned char *board;
2005 int x, y, mainanchor, mainpos, dragpos, solvepos, solvesrc, solvedst;
2009 * The initial contents of the window are not guaranteed
2010 * and can vary with front ends. To be on the safe side,
2011 * all games should start by drawing a big
2012 * background-colour rectangle covering the whole window.
2014 draw_rect(dr, 0, 0, 10*ds->tilesize, 10*ds->tilesize, COL_BACKGROUND);
2019 * Construct the board we'll be displaying (which may be
2020 * different from the one in state if ui describes a drag in
2023 board = snewn(wh, unsigned char);
2024 memcpy(board, state->board, wh);
2026 int mpret = move_piece(w, h, state->board, board,
2027 state->imm->forcefield,
2028 ui->drag_anchor, ui->drag_currpos);
2033 solvesrc = state->soln->moves[state->soln_index*2];
2034 solvedst = state->soln->moves[state->soln_index*2+1];
2035 if (solvesrc == state->lastmoved_pos)
2036 solvesrc = state->lastmoved;
2037 if (solvesrc == ui->drag_anchor)
2038 solvesrc = ui->drag_currpos;
2040 solvesrc = solvedst = -1;
2043 * Build a dsf out of that board, so we can conveniently tell
2044 * which edges are connected and which aren't.
2048 for (y = 0; y < h; y++)
2049 for (x = 0; x < w; x++) {
2052 if (ISDIST(board[i]))
2053 dsf_merge(dsf, i, i - board[i]);
2054 if (board[i] == MAINANCHOR)
2056 if (board[i] == WALL) {
2057 if (x > 0 && board[i-1] == WALL)
2058 dsf_merge(dsf, i, i-1);
2059 if (y > 0 && board[i-w] == WALL)
2060 dsf_merge(dsf, i, i-w);
2063 assert(mainanchor >= 0);
2064 mainpos = dsf_canonify(dsf, mainanchor);
2065 dragpos = ui->drag_currpos > 0 ? dsf_canonify(dsf, ui->drag_currpos) : -1;
2066 solvepos = solvesrc >= 0 ? dsf_canonify(dsf, solvesrc) : -1;
2069 * Now we can construct the data about what we want to draw.
2071 for (y = 0; y < h; y++)
2072 for (x = 0; x < w; x++) {
2079 * See if this square is part of the target area.
2081 j = i + mainanchor - (state->ty * w + state->tx);
2082 while (j >= 0 && j < wh && ISDIST(board[j]))
2084 if (j == mainanchor)
2089 if (state->imm->forcefield[i])
2090 val |= BG_FORCEFIELD;
2092 if (flashtime > 0) {
2093 int flashtype = (int)(flashtime / FLASH_INTERVAL) & 1;
2094 val |= (flashtype ? FLASH_LOW : FLASH_HIGH);
2097 if (board[i] != EMPTY) {
2098 canon = dsf_canonify(dsf, i);
2100 if (board[i] == WALL)
2102 else if (canon == mainpos)
2106 if (canon == dragpos)
2108 if (canon == solvepos)
2109 val |= FG_SOLVEPIECE;
2112 * Now look around to see if other squares
2113 * belonging to the same block are adjacent to us.
2115 val |= find_piecepart(w, h, dsf, x, y) << FG_MAINPIECESH;
2119 * If we're in the middle of showing a solution,
2120 * display a shadow piece for the target of the
2123 if (solvepos >= 0) {
2124 int si = i - solvedst + solvesrc;
2125 if (si >= 0 && si < wh && dsf_canonify(dsf, si) == solvepos) {
2126 val |= find_piecepart(w, h, dsf,
2127 si % w, si / w) << FG_SHADOWSH;
2132 if (val != ds->grid[i]) {
2133 draw_tile(dr, ds, x, y, val);
2139 * Update the status bar.
2142 char statusbuf[256];
2144 sprintf(statusbuf, "%sMoves: %d",
2145 (state->completed >= 0 ?
2146 (state->cheated ? "Auto-solved. " : "COMPLETED! ") :
2147 (state->cheated ? "Auto-solver used. " : "")),
2148 (state->completed >= 0 ? state->completed : state->movecount));
2149 if (state->minmoves >= 0)
2150 sprintf(statusbuf+strlen(statusbuf), " (min %d)",
2153 status_bar(dr, statusbuf);
2160 static float game_anim_length(game_state *oldstate, game_state *newstate,
2161 int dir, game_ui *ui)
2166 static float game_flash_length(game_state *oldstate, game_state *newstate,
2167 int dir, game_ui *ui)
2169 if (oldstate->completed < 0 && newstate->completed >= 0)
2175 static int game_timing_state(game_state *state, game_ui *ui)
2180 static void game_print_size(game_params *params, float *x, float *y)
2184 static void game_print(drawing *dr, game_state *state, int tilesize)
2189 #define thegame nullgame
2192 const struct game thegame = {
2193 "Slide", NULL, NULL,
2200 TRUE, game_configure, custom_params,
2208 TRUE, game_text_format,
2216 PREFERRED_TILESIZE, game_compute_size, game_set_size,
2219 game_free_drawstate,
2223 FALSE, FALSE, game_print_size, game_print,
2224 TRUE, /* wants_statusbar */
2225 FALSE, game_timing_state,
2229 #ifdef STANDALONE_SOLVER
2233 int main(int argc, char **argv)
2237 char *id = NULL, *desc, *err;
2239 int ret, really_verbose = FALSE;
2242 while (--argc > 0) {
2244 if (!strcmp(p, "-v")) {
2245 really_verbose = TRUE;
2246 } else if (!strcmp(p, "-c")) {
2248 } else if (*p == '-') {
2249 fprintf(stderr, "%s: unrecognised option `%s'\n", argv[0], p);
2257 fprintf(stderr, "usage: %s [-c | -v] <game_id>\n", argv[0]);
2261 desc = strchr(id, ':');
2263 fprintf(stderr, "%s: game id expects a colon in it\n", argv[0]);
2268 p = default_params();
2269 decode_params(p, id);
2270 err = validate_desc(p, desc);
2272 fprintf(stderr, "%s: %s\n", argv[0], err);
2275 s = new_game(NULL, p, desc);
2277 ret = solve_board(s->w, s->h, s->board, s->imm->forcefield,
2278 s->tx, s->ty, -1, &moves);
2280 printf("No solution found\n");
2284 printf("%d moves required\n", ret);
2289 char *text = board_text_format(s->w, s->h, s->board,
2290 s->imm->forcefield);
2293 printf("position %d:\n%s", index, text);
2299 moveret = move_piece(s->w, s->h, s->board,
2300 s2->board, s->imm->forcefield,
2301 moves[index*2], moves[index*2+1]);