ref: f21d3e4c74b23380f397a7ee0416928ee971a15d
dir: /unfinished/slide.c/
/* * slide.c: Implementation of the block-sliding puzzle `Klotski'. */ /* * TODO: * * - Improve the generator. * * actually, we seem to be mostly sensible already now. I * want more choice over the type of main block and location * of the exit/target, and I think I probably ought to give * up on compactness and just bite the bullet and have the * target area right outside the main wall, but mostly I * think it's OK. * * the move limit tends to make the game _slower_ to * generate, which is odd. Perhaps investigate why. * * - Improve the graphics. * * All the colours are a bit wishy-washy. _Some_ dark * colours would surely not be excessive? Probably darken * the tiles, the walls and the main block, and leave the * target marker pale. * * The cattle grid effect is still disgusting. Think of * something completely different. * * The highlight for next-piece-to-move in the solver is * excessive, and the shadow blends in too well with the * piece lowlights. Adjust both. */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <assert.h> #include <ctype.h> #include <math.h> #include "puzzles.h" #include "tree234.h" /* * The implementation of this game revolves around the insight * which makes an exhaustive-search solver feasible: although * there are many blocks which can be rearranged in many ways, any * two blocks of the same shape are _indistinguishable_ and hence * the number of _distinct_ board layouts is generally much * smaller. So we adopt a representation for board layouts which * is inherently canonical, i.e. there are no two distinct * representations which encode indistinguishable layouts. * * The way we do this is to encode each square of the board, in * the normal left-to-right top-to-bottom order, as being one of * the following things: * - the first square (in the given order) of a block (`anchor') * - special case of the above: the anchor for the _main_ block * (i.e. the one which the aim of the game is to get to the * target position) * - a subsequent square of a block whose previous square was N * squares ago * - an impassable wall * * (We also separately store data about which board positions are * forcefields only passable by the main block. We can't encode * that in the main board data, because then the main block would * destroy forcefields as it went over them.) * * Hence, for example, a 2x2 square block would be encoded as * ANCHOR, followed by DIST(1), and w-2 squares later on there * would be DIST(w-1) followed by DIST(1). So if you start at the * last of those squares, the DIST numbers give you a linked list * pointing back through all the other squares in the same block. * * So the solver simply does a bfs over all reachable positions, * encoding them in this format and storing them in a tree234 to * ensure it doesn't ever revisit an already-analysed position. */ enum { /* * The colours are arranged here so that every base colour is * directly followed by its highlight colour and then its * lowlight colour. Do not break this, or draw_tile() will get * confused. */ COL_BACKGROUND, COL_HIGHLIGHT, COL_LOWLIGHT, COL_DRAGGING, COL_DRAGGING_HIGHLIGHT, COL_DRAGGING_LOWLIGHT, COL_MAIN, COL_MAIN_HIGHLIGHT, COL_MAIN_LOWLIGHT, COL_MAIN_DRAGGING, COL_MAIN_DRAGGING_HIGHLIGHT, COL_MAIN_DRAGGING_LOWLIGHT, COL_TARGET, COL_TARGET_HIGHLIGHT, COL_TARGET_LOWLIGHT, NCOLOURS }; /* * Board layout is a simple array of bytes. Each byte holds: */ #define ANCHOR 255 /* top-left-most square of some piece */ #define MAINANCHOR 254 /* anchor of _main_ piece */ #define EMPTY 253 /* empty square */ #define WALL 252 /* immovable wall */ #define MAXDIST 251 /* all other values indicate distance back to previous square of same block */ #define ISDIST(x) ( (unsigned char)((x)-1) <= MAXDIST-1 ) #define DIST(x) (x) #define ISANCHOR(x) ( (x)==ANCHOR || (x)==MAINANCHOR ) #define ISBLOCK(x) ( ISANCHOR(x) || ISDIST(x) ) /* * MAXDIST is the largest DIST value we can encode. This must * therefore also be the maximum puzzle width in theory (although * solver running time will dictate a much smaller limit in * practice). */ #define MAXWID MAXDIST struct game_params { int w, h; int maxmoves; }; struct game_immutable_state { int refcount; bool *forcefield; }; struct game_solution { int nmoves; int *moves; /* just like from solve_board() */ int refcount; }; struct game_state { int w, h; unsigned char *board; int tx, ty; /* target coords for MAINANCHOR */ int minmoves; /* for display only */ int lastmoved, lastmoved_pos; /* for move counting */ int movecount; int completed; bool cheated; struct game_immutable_state *imm; struct game_solution *soln; int soln_index; }; static game_params *default_params(void) { game_params *ret = snew(game_params); ret->w = 7; ret->h = 6; ret->maxmoves = 40; return ret; } static const struct game_params slide_presets[] = { {7, 6, 25}, {7, 6, -1}, {8, 6, -1}, }; static bool game_fetch_preset(int i, char **name, game_params **params) { game_params *ret; char str[80]; if (i < 0 || i >= lenof(slide_presets)) return false; ret = snew(game_params); *ret = slide_presets[i]; sprintf(str, "%dx%d", ret->w, ret->h); if (ret->maxmoves >= 0) sprintf(str + strlen(str), ", max %d moves", ret->maxmoves); else sprintf(str + strlen(str), ", no move limit"); *name = dupstr(str); *params = ret; return true; } static void free_params(game_params *params) { sfree(params); } static game_params *dup_params(const game_params *params) { game_params *ret = snew(game_params); *ret = *params; /* structure copy */ return ret; } static void decode_params(game_params *params, char const *string) { params->w = params->h = atoi(string); while (*string && isdigit((unsigned char)*string)) string++; if (*string == 'x') { string++; params->h = atoi(string); while (*string && isdigit((unsigned char)*string)) string++; } if (*string == 'm') { string++; params->maxmoves = atoi(string); while (*string && isdigit((unsigned char)*string)) string++; } else if (*string == 'u') { string++; params->maxmoves = -1; } } static char *encode_params(const game_params *params, bool full) { char data[256]; sprintf(data, "%dx%d", params->w, params->h); if (params->maxmoves >= 0) sprintf(data + strlen(data), "m%d", params->maxmoves); else sprintf(data + strlen(data), "u"); return dupstr(data); } static config_item *game_configure(const game_params *params) { config_item *ret; char buf[80]; ret = snewn(4, config_item); ret[0].name = "Width"; ret[0].type = C_STRING; sprintf(buf, "%d", params->w); ret[0].u.string.sval = dupstr(buf); ret[1].name = "Height"; ret[1].type = C_STRING; sprintf(buf, "%d", params->h); ret[1].u.string.sval = dupstr(buf); ret[2].name = "Solution length limit"; ret[2].type = C_STRING; sprintf(buf, "%d", params->maxmoves); ret[2].u.string.sval = dupstr(buf); ret[3].name = NULL; ret[3].type = C_END; return ret; } static game_params *custom_params(const config_item *cfg) { game_params *ret = snew(game_params); ret->w = atoi(cfg[0].u.string.sval); ret->h = atoi(cfg[1].u.string.sval); ret->maxmoves = atoi(cfg[2].u.string.sval); return ret; } static const char *validate_params(const game_params *params, bool full) { if (params->w > MAXWID) return "Width must be at most " STR(MAXWID); if (params->w < 5) return "Width must be at least 5"; if (params->h < 4) return "Height must be at least 4"; return NULL; } static char *board_text_format(int w, int h, unsigned char *data, bool *forcefield) { int wh = w*h; int *dsf = snew_dsf(wh); int i, x, y; int retpos, retlen = (w*2+2)*(h*2+1)+1; char *ret = snewn(retlen, char); for (i = 0; i < wh; i++) if (ISDIST(data[i])) dsf_merge(dsf, i - data[i], i); retpos = 0; for (y = 0; y < 2*h+1; y++) { for (x = 0; x < 2*w+1; x++) { int v; int i = (y/2)*w+(x/2); #define dtype(i) (ISBLOCK(data[i]) ? \ dsf_canonify(dsf, i) : data[i]) #define dchar(t) ((t)==EMPTY ? ' ' : (t)==WALL ? '#' : \ data[t] == MAINANCHOR ? '*' : '%') if (y % 2 && x % 2) { int j = dtype(i); v = dchar(j); } else if (y % 2 && !(x % 2)) { int j1 = (x > 0 ? dtype(i-1) : -1); int j2 = (x < 2*w ? dtype(i) : -1); if (j1 != j2) v = '|'; else v = dchar(j1); } else if (!(y % 2) && (x % 2)) { int j1 = (y > 0 ? dtype(i-w) : -1); int j2 = (y < 2*h ? dtype(i) : -1); if (j1 != j2) v = '-'; else v = dchar(j1); } else { int j1 = (x > 0 && y > 0 ? dtype(i-w-1) : -1); int j2 = (x > 0 && y < 2*h ? dtype(i-1) : -1); int j3 = (x < 2*w && y > 0 ? dtype(i-w) : -1); int j4 = (x < 2*w && y < 2*h ? dtype(i) : -1); if (j1 == j2 && j2 == j3 && j3 == j4) v = dchar(j1); else if (j1 == j2 && j3 == j4) v = '|'; else if (j1 == j3 && j2 == j4) v = '-'; else v = '+'; } assert(retpos < retlen); ret[retpos++] = v; } assert(retpos < retlen); ret[retpos++] = '\n'; } assert(retpos < retlen); ret[retpos++] = '\0'; assert(retpos == retlen); return ret; } /* ---------------------------------------------------------------------- * Solver. */ /* * During solver execution, the set of visited board positions is * stored as a tree234 of the following structures. `w', `h' and * `data' are obvious in meaning; `dist' represents the minimum * distance to reach this position from the starting point. * * `prev' links each board to the board position from which it was * most efficiently derived. */ struct board { int w, h; int dist; struct board *prev; unsigned char *data; }; static int boardcmp(void *av, void *bv) { struct board *a = (struct board *)av; struct board *b = (struct board *)bv; return memcmp(a->data, b->data, a->w * a->h); } static struct board *newboard(int w, int h, unsigned char *data) { struct board *b = malloc(sizeof(struct board) + w*h); b->data = (unsigned char *)b + sizeof(struct board); memcpy(b->data, data, w*h); b->w = w; b->h = h; b->dist = -1; b->prev = NULL; return b; } /* * The actual solver. Given a board, attempt to find the minimum * length of move sequence which moves MAINANCHOR to (tx,ty), or * -1 if no solution exists. Returns that minimum length. * * Also, if `moveout' is provided, writes out the moves in the * form of a sequence of pairs of integers indicating the source * and destination points of the anchor of the moved piece in each * move. Exactly twice as many integers are written as the number * returned from solve_board(), and `moveout' receives an int * * which is a pointer to a dynamically allocated array. */ static int solve_board(int w, int h, unsigned char *board, bool *forcefield, int tx, int ty, int movelimit, int **moveout) { int wh = w*h; struct board *b, *b2, *b3; int *next, *which; bool *anchors, *movereached; int *movequeue, mqhead, mqtail; tree234 *sorted, *queue; int i, j, dir; int qlen, lastdist; int ret; #ifdef SOLVER_DIAGNOSTICS { char *t = board_text_format(w, h, board); for (i = 0; i < h; i++) { for (j = 0; j < w; j++) { int c = board[i*w+j]; if (ISDIST(c)) printf("D%-3d", c); else if (c == MAINANCHOR) printf("M "); else if (c == ANCHOR) printf("A "); else if (c == WALL) printf("W "); else if (c == EMPTY) printf("E "); } printf("\n"); } printf("Starting solver for:\n%s\n", t); sfree(t); } #endif sorted = newtree234(boardcmp); queue = newtree234(NULL); b = newboard(w, h, board); b->dist = 0; add234(sorted, b); addpos234(queue, b, 0); qlen = 1; next = snewn(wh, int); anchors = snewn(wh, bool); which = snewn(wh, int); movereached = snewn(wh, bool); movequeue = snewn(wh, int); lastdist = -1; while ((b = delpos234(queue, 0)) != NULL) { qlen--; if (movelimit >= 0 && b->dist >= movelimit) { /* * The problem is not soluble in under `movelimit' * moves, so we can quit right now. */ b2 = NULL; goto done; } if (b->dist != lastdist) { #ifdef SOLVER_DIAGNOSTICS printf("dist %d (%d)\n", b->dist, count234(sorted)); #endif lastdist = b->dist; } /* * Find all the anchors and form a linked list of the * squares within each block. */ for (i = 0; i < wh; i++) { next[i] = -1; anchors[i] = false; which[i] = -1; if (ISANCHOR(b->data[i])) { anchors[i] = true; which[i] = i; } else if (ISDIST(b->data[i])) { j = i - b->data[i]; next[j] = i; which[i] = which[j]; } } /* * For each anchor, do an array-based BFS to find all the * places we can slide it to. */ for (i = 0; i < wh; i++) { if (!anchors[i]) continue; mqhead = mqtail = 0; for (j = 0; j < wh; j++) movereached[j] = false; movequeue[mqtail++] = i; while (mqhead < mqtail) { int pos = movequeue[mqhead++]; /* * Try to move in each direction from here. */ for (dir = 0; dir < 4; dir++) { int dx = (dir == 0 ? -1 : dir == 1 ? +1 : 0); int dy = (dir == 2 ? -1 : dir == 3 ? +1 : 0); int offset = dy*w + dx; int newpos = pos + offset; int d = newpos - i; /* * For each square involved in this block, * check to see if the square d spaces away * from it is either empty or part of the same * block. */ for (j = i; j >= 0; j = next[j]) { int jy = (pos+j-i) / w + dy, jx = (pos+j-i) % w + dx; if (jy >= 0 && jy < h && jx >= 0 && jx < w && ((b->data[j+d] == EMPTY || which[j+d] == i) && (b->data[i] == MAINANCHOR || !forcefield[j+d]))) /* ok */; else break; } if (j >= 0) continue; /* this direction wasn't feasible */ /* * If we've already tried moving this piece * here, leave it. */ if (movereached[newpos]) continue; movereached[newpos] = true; movequeue[mqtail++] = newpos; /* * We have a viable move. Make it. */ b2 = newboard(w, h, b->data); for (j = i; j >= 0; j = next[j]) b2->data[j] = EMPTY; for (j = i; j >= 0; j = next[j]) b2->data[j+d] = b->data[j]; b3 = add234(sorted, b2); if (b3 != b2) { sfree(b2); /* we already got one */ } else { b2->dist = b->dist + 1; b2->prev = b; addpos234(queue, b2, qlen++); if (b2->data[ty*w+tx] == MAINANCHOR) goto done; /* search completed! */ } } } } } b2 = NULL; done: if (b2) { ret = b2->dist; if (moveout) { /* * Now b2 represents the solved position. Backtrack to * output the solution. */ *moveout = snewn(ret * 2, int); j = ret * 2; while (b2->prev) { int from = -1, to = -1; b = b2->prev; /* * Scan b and b2 to find out which piece has * moved. */ for (i = 0; i < wh; i++) { if (ISANCHOR(b->data[i]) && !ISANCHOR(b2->data[i])) { assert(from == -1); from = i; } else if (!ISANCHOR(b->data[i]) && ISANCHOR(b2->data[i])){ assert(to == -1); to = i; } } assert(from >= 0 && to >= 0); assert(j >= 2); (*moveout)[--j] = to; (*moveout)[--j] = from; b2 = b; } assert(j == 0); } } else { ret = -1; /* no solution */ if (moveout) *moveout = NULL; } freetree234(queue); while ((b = delpos234(sorted, 0)) != NULL) sfree(b); freetree234(sorted); sfree(next); sfree(anchors); sfree(movereached); sfree(movequeue); sfree(which); return ret; } /* ---------------------------------------------------------------------- * Random board generation. */ static void generate_board(int w, int h, int *rtx, int *rty, int *minmoves, random_state *rs, unsigned char **rboard, bool **rforcefield, int movelimit) { int wh = w*h; unsigned char *board, *board2; bool *forcefield; bool *tried_merge; int *dsf; int *list, nlist, pos; int tx, ty; int i, j; int moves = 0; /* placate optimiser */ /* * Set up a board and fill it with singletons, except for a * border of walls. */ board = snewn(wh, unsigned char); forcefield = snewn(wh, bool); board2 = snewn(wh, unsigned char); memset(board, ANCHOR, wh); memset(forcefield, 0, wh * sizeof(bool)); for (i = 0; i < w; i++) board[i] = board[i+w*(h-1)] = WALL; for (i = 0; i < h; i++) board[i*w] = board[i*w+(w-1)] = WALL; tried_merge = snewn(wh * wh, bool); memset(tried_merge, 0, wh*wh * sizeof(bool)); dsf = snew_dsf(wh); /* * Invent a main piece at one extreme. (FIXME: vary the * extreme, and the piece.) */ board[w+1] = MAINANCHOR; board[w+2] = DIST(1); board[w*2+1] = DIST(w-1); board[w*2+2] = DIST(1); /* * Invent a target position. (FIXME: vary this too.) */ tx = w-2; ty = h-3; forcefield[ty*w+tx+1] = true; forcefield[(ty+1)*w+tx+1] = true; board[ty*w+tx+1] = board[(ty+1)*w+tx+1] = EMPTY; /* * Gradually remove singletons until the game becomes soluble. */ for (j = w; j-- > 0 ;) for (i = h; i-- > 0 ;) if (board[i*w+j] == ANCHOR) { /* * See if the board is already soluble. */ if ((moves = solve_board(w, h, board, forcefield, tx, ty, movelimit, NULL)) >= 0) goto soluble; /* * Otherwise, remove this piece. */ board[i*w+j] = EMPTY; } assert(!"We shouldn't get here"); soluble: /* * Make a list of all the inter-block edges on the board. */ list = snewn(wh*2, int); nlist = 0; for (i = 0; i+1 < w; i++) for (j = 0; j < h; j++) list[nlist++] = (j*w+i) * 2 + 0; /* edge to the right of j*w+i */ for (j = 0; j+1 < h; j++) for (i = 0; i < w; i++) list[nlist++] = (j*w+i) * 2 + 1; /* edge below j*w+i */ /* * Now go through that list in random order, trying to merge * the blocks on each side of each edge. */ shuffle(list, nlist, sizeof(*list), rs); while (nlist > 0) { int x1, y1, p1, c1; int x2, y2, p2, c2; pos = list[--nlist]; y1 = y2 = pos / (w*2); x1 = x2 = (pos / 2) % w; if (pos % 2) y2++; else x2++; p1 = y1*w+x1; p2 = y2*w+x2; /* * Immediately abandon the attempt if we've already tried * to merge the same pair of blocks along a different * edge. */ c1 = dsf_canonify(dsf, p1); c2 = dsf_canonify(dsf, p2); if (tried_merge[c1 * wh + c2]) continue; /* * In order to be mergeable, these two squares must each * either be, or belong to, a non-main anchor, and their * anchors must also be distinct. */ if (!ISBLOCK(board[p1]) || !ISBLOCK(board[p2])) continue; while (ISDIST(board[p1])) p1 -= board[p1]; while (ISDIST(board[p2])) p2 -= board[p2]; if (board[p1] == MAINANCHOR || board[p2] == MAINANCHOR || p1 == p2) continue; /* * We can merge these blocks. Try it, and see if the * puzzle remains soluble. */ memcpy(board2, board, wh); j = -1; while (p1 < wh || p2 < wh) { /* * p1 and p2 are the squares at the head of each block * list. Pick the smaller one and put it on the output * block list. */ i = min(p1, p2); if (j < 0) { board[i] = ANCHOR; } else { assert(i - j <= MAXDIST); board[i] = DIST(i - j); } j = i; /* * Now advance whichever list that came from. */ if (i == p1) { do { p1++; } while (p1 < wh && board[p1] != DIST(p1-i)); } else { do { p2++; } while (p2 < wh && board[p2] != DIST(p2-i)); } } j = solve_board(w, h, board, forcefield, tx, ty, movelimit, NULL); if (j < 0) { /* * Didn't work. Revert the merge. */ memcpy(board, board2, wh); tried_merge[c1 * wh + c2] = true; tried_merge[c2 * wh + c1] = true; } else { int c; moves = j; dsf_merge(dsf, c1, c2); c = dsf_canonify(dsf, c1); for (i = 0; i < wh; i++) tried_merge[c*wh+i] = (tried_merge[c1*wh+i] || tried_merge[c2*wh+i]); for (i = 0; i < wh; i++) tried_merge[i*wh+c] = (tried_merge[i*wh+c1] || tried_merge[i*wh+c2]); } } sfree(dsf); sfree(list); sfree(tried_merge); sfree(board2); *rtx = tx; *rty = ty; *rboard = board; *rforcefield = forcefield; *minmoves = moves; } /* ---------------------------------------------------------------------- * End of solver/generator code. */ static char *new_game_desc(const game_params *params, random_state *rs, char **aux, bool interactive) { int w = params->w, h = params->h, wh = w*h; int tx, ty, minmoves; unsigned char *board; bool *forcefield; char *ret, *p; int i; generate_board(params->w, params->h, &tx, &ty, &minmoves, rs, &board, &forcefield, params->maxmoves); #ifdef GENERATOR_DIAGNOSTICS { char *t = board_text_format(params->w, params->h, board); printf("%s\n", t); sfree(t); } #endif /* * Encode as a game ID. */ ret = snewn(wh * 6 + 40, char); p = ret; i = 0; while (i < wh) { if (ISDIST(board[i])) { p += sprintf(p, "d%d", board[i]); i++; } else { int count = 1; int b = board[i]; bool f = forcefield[i]; int c = (b == ANCHOR ? 'a' : b == MAINANCHOR ? 'm' : b == EMPTY ? 'e' : /* b == WALL ? */ 'w'); if (f) *p++ = 'f'; *p++ = c; i++; while (i < wh && board[i] == b && forcefield[i] == f) i++, count++; if (count > 1) p += sprintf(p, "%d", count); } } p += sprintf(p, ",%d,%d,%d", tx, ty, minmoves); ret = sresize(ret, p+1 - ret, char); sfree(board); sfree(forcefield); return ret; } static const char *validate_desc(const game_params *params, const char *desc) { int w = params->w, h = params->h, wh = w*h; bool *active; int *link; int mains = 0; int i, tx, ty, minmoves; char *ret; active = snewn(wh, bool); link = snewn(wh, int); i = 0; while (*desc && *desc != ',') { if (i >= wh) { ret = "Too much data in game description"; goto done; } link[i] = -1; active[i] = false; if (*desc == 'f' || *desc == 'F') { desc++; if (!*desc) { ret = "Expected another character after 'f' in game " "description"; goto done; } } if (*desc == 'd' || *desc == 'D') { int dist; desc++; if (!isdigit((unsigned char)*desc)) { ret = "Expected a number after 'd' in game description"; goto done; } dist = atoi(desc); while (*desc && isdigit((unsigned char)*desc)) desc++; if (dist <= 0 || dist > i) { ret = "Out-of-range number after 'd' in game description"; goto done; } if (!active[i - dist]) { ret = "Invalid back-reference in game description"; goto done; } link[i] = i - dist; active[i] = true; active[link[i]] = false; i++; } else { int c = *desc++; int count = 1; if (!strchr("aAmMeEwW", c)) { ret = "Invalid character in game description"; goto done; } if (isdigit((unsigned char)*desc)) { count = atoi(desc); while (*desc && isdigit((unsigned char)*desc)) desc++; } if (i + count > wh) { ret = "Too much data in game description"; goto done; } while (count-- > 0) { active[i] = (strchr("aAmM", c) != NULL); link[i] = -1; if (strchr("mM", c) != NULL) { mains++; } i++; } } } if (mains != 1) { ret = (mains == 0 ? "No main piece specified in game description" : "More than one main piece specified in game description"); goto done; } if (i < wh) { ret = "Not enough data in game description"; goto done; } /* * Now read the target coordinates. */ i = sscanf(desc, ",%d,%d,%d", &tx, &ty, &minmoves); if (i < 2) { ret = "No target coordinates specified"; goto done; /* * (but minmoves is optional) */ } ret = NULL; done: sfree(active); sfree(link); return ret; } static game_state *new_game(midend *me, const game_params *params, const char *desc) { int w = params->w, h = params->h, wh = w*h; game_state *state; int i; state = snew(game_state); state->w = w; state->h = h; state->board = snewn(wh, unsigned char); state->lastmoved = state->lastmoved_pos = -1; state->movecount = 0; state->imm = snew(struct game_immutable_state); state->imm->refcount = 1; state->imm->forcefield = snewn(wh, bool); i = 0; while (*desc && *desc != ',') { bool f = false; assert(i < wh); if (*desc == 'f') { f = true; desc++; assert(*desc); } if (*desc == 'd' || *desc == 'D') { int dist; desc++; dist = atoi(desc); while (*desc && isdigit((unsigned char)*desc)) desc++; state->board[i] = DIST(dist); state->imm->forcefield[i] = f; i++; } else { int c = *desc++; int count = 1; if (isdigit((unsigned char)*desc)) { count = atoi(desc); while (*desc && isdigit((unsigned char)*desc)) desc++; } assert(i + count <= wh); c = (c == 'a' || c == 'A' ? ANCHOR : c == 'm' || c == 'M' ? MAINANCHOR : c == 'e' || c == 'E' ? EMPTY : /* c == 'w' || c == 'W' ? */ WALL); while (count-- > 0) { state->board[i] = c; state->imm->forcefield[i] = f; i++; } } } /* * Now read the target coordinates. */ state->tx = state->ty = 0; state->minmoves = -1; i = sscanf(desc, ",%d,%d,%d", &state->tx, &state->ty, &state->minmoves); if (state->board[state->ty*w+state->tx] == MAINANCHOR) state->completed = 0; /* already complete! */ else state->completed = -1; state->cheated = false; state->soln = NULL; state->soln_index = -1; return state; } static game_state *dup_game(const game_state *state) { int w = state->w, h = state->h, wh = w*h; game_state *ret = snew(game_state); ret->w = state->w; ret->h = state->h; ret->board = snewn(wh, unsigned char); memcpy(ret->board, state->board, wh); ret->tx = state->tx; ret->ty = state->ty; ret->minmoves = state->minmoves; ret->lastmoved = state->lastmoved; ret->lastmoved_pos = state->lastmoved_pos; ret->movecount = state->movecount; ret->completed = state->completed; ret->cheated = state->cheated; ret->imm = state->imm; ret->imm->refcount++; ret->soln = state->soln; ret->soln_index = state->soln_index; if (ret->soln) ret->soln->refcount++; return ret; } static void free_game(game_state *state) { if (--state->imm->refcount <= 0) { sfree(state->imm->forcefield); sfree(state->imm); } if (state->soln && --state->soln->refcount <= 0) { sfree(state->soln->moves); sfree(state->soln); } sfree(state->board); sfree(state); } static char *solve_game(const game_state *state, const game_state *currstate, const char *aux, const char **error) { int *moves; int nmoves; int i; char *ret, *p, sep; /* * Run the solver and attempt to find the shortest solution * from the current position. */ nmoves = solve_board(state->w, state->h, state->board, state->imm->forcefield, state->tx, state->ty, -1, &moves); if (nmoves < 0) { *error = "Unable to find a solution to this puzzle"; return NULL; } if (nmoves == 0) { *error = "Puzzle is already solved"; return NULL; } /* * Encode the resulting solution as a move string. */ ret = snewn(nmoves * 40, char); p = ret; sep = 'S'; for (i = 0; i < nmoves; i++) { p += sprintf(p, "%c%d-%d", sep, moves[i*2], moves[i*2+1]); sep = ','; } sfree(moves); assert(p - ret < nmoves * 40); ret = sresize(ret, p+1 - ret, char); return ret; } static bool game_can_format_as_text_now(const game_params *params) { return true; } static char *game_text_format(const game_state *state) { return board_text_format(state->w, state->h, state->board, state->imm->forcefield); } struct game_ui { bool dragging; int drag_anchor; int drag_offset_x, drag_offset_y; int drag_currpos; bool *reachable; int *bfs_queue; /* used as scratch in interpret_move */ }; static game_ui *new_ui(const game_state *state) { int w = state->w, h = state->h, wh = w*h; game_ui *ui = snew(game_ui); ui->dragging = false; ui->drag_anchor = ui->drag_currpos = -1; ui->drag_offset_x = ui->drag_offset_y = -1; ui->reachable = snewn(wh, bool); memset(ui->reachable, 0, wh * sizeof(bool)); ui->bfs_queue = snewn(wh, int); return ui; } static void free_ui(game_ui *ui) { sfree(ui->bfs_queue); sfree(ui->reachable); sfree(ui); } static char *encode_ui(const game_ui *ui) { return NULL; } static void decode_ui(game_ui *ui, const char *encoding) { } static void game_changed_state(game_ui *ui, const game_state *oldstate, const game_state *newstate) { } #define PREFERRED_TILESIZE 32 #define TILESIZE (ds->tilesize) #define BORDER (TILESIZE/2) #define COORD(x) ( (x) * TILESIZE + BORDER ) #define FROMCOORD(x) ( ((x) - BORDER + TILESIZE) / TILESIZE - 1 ) #define BORDER_WIDTH (1 + TILESIZE/20) #define HIGHLIGHT_WIDTH (1 + TILESIZE/16) #define FLASH_INTERVAL 0.10F #define FLASH_TIME 3*FLASH_INTERVAL struct game_drawstate { int tilesize; int w, h; unsigned long *grid; /* what's currently displayed */ bool started; }; static char *interpret_move(const game_state *state, game_ui *ui, const game_drawstate *ds, int x, int y, int button) { int w = state->w, h = state->h, wh = w*h; int tx, ty, i, j; int qhead, qtail; if (button == LEFT_BUTTON) { tx = FROMCOORD(x); ty = FROMCOORD(y); if (tx < 0 || tx >= w || ty < 0 || ty >= h || !ISBLOCK(state->board[ty*w+tx])) return NULL; /* this click has no effect */ /* * User has clicked on a block. Find the block's anchor * and register that we've started dragging it. */ i = ty*w+tx; while (ISDIST(state->board[i])) i -= state->board[i]; assert(i >= 0 && i < wh); ui->dragging = true; ui->drag_anchor = i; ui->drag_offset_x = tx - (i % w); ui->drag_offset_y = ty - (i / w); ui->drag_currpos = i; /* * Now we immediately bfs out from the current location of * the anchor, to find all the places to which this block * can be dragged. */ memset(ui->reachable, 0, wh * sizeof(bool)); qhead = qtail = 0; ui->reachable[i] = true; ui->bfs_queue[qtail++] = i; for (j = i; j < wh; j++) if (state->board[j] == DIST(j - i)) i = j; while (qhead < qtail) { int pos = ui->bfs_queue[qhead++]; int x = pos % w, y = pos / w; int dir; for (dir = 0; dir < 4; dir++) { int dx = (dir == 0 ? -1 : dir == 1 ? +1 : 0); int dy = (dir == 2 ? -1 : dir == 3 ? +1 : 0); int newpos; if (x + dx < 0 || x + dx >= w || y + dy < 0 || y + dy >= h) continue; newpos = pos + dy*w + dx; if (ui->reachable[newpos]) continue; /* already done this one */ /* * Now search the grid to see if the block we're * dragging could fit into this space. */ for (j = i; j >= 0; j = (ISDIST(state->board[j]) ? j - state->board[j] : -1)) { int jx = (j+pos-ui->drag_anchor) % w; int jy = (j+pos-ui->drag_anchor) / w; int j2; if (jx + dx < 0 || jx + dx >= w || jy + dy < 0 || jy + dy >= h) break; /* this position isn't valid at all */ j2 = (j+pos-ui->drag_anchor) + dy*w + dx; if (state->board[j2] == EMPTY && (!state->imm->forcefield[j2] || state->board[ui->drag_anchor] == MAINANCHOR)) continue; while (ISDIST(state->board[j2])) j2 -= state->board[j2]; assert(j2 >= 0 && j2 < wh); if (j2 == ui->drag_anchor) continue; else break; } if (j < 0) { /* * If we got to the end of that loop without * disqualifying this position, mark it as * reachable for this drag. */ ui->reachable[newpos] = true; ui->bfs_queue[qtail++] = newpos; } } } /* * And that's it. Update the display to reflect the start * of a drag. */ return UI_UPDATE; } else if (button == LEFT_DRAG && ui->dragging) { int dist, distlimit, dx, dy, s, px, py; tx = FROMCOORD(x); ty = FROMCOORD(y); tx -= ui->drag_offset_x; ty -= ui->drag_offset_y; /* * Now search outwards from (tx,ty), in order of Manhattan * distance, until we find a reachable square. */ distlimit = w+tx; distlimit = max(distlimit, h+ty); distlimit = max(distlimit, tx); distlimit = max(distlimit, ty); for (dist = 0; dist <= distlimit; dist++) { for (dx = -dist; dx <= dist; dx++) for (s = -1; s <= +1; s += 2) { dy = s * (dist - abs(dx)); px = tx + dx; py = ty + dy; if (px >= 0 && px < w && py >= 0 && py < h && ui->reachable[py*w+px]) { ui->drag_currpos = py*w+px; return UI_UPDATE; } } } return NULL; /* give up - this drag has no effect */ } else if (button == LEFT_RELEASE && ui->dragging) { char data[256], *str; /* * Terminate the drag, and if the piece has actually moved * then return a move string quoting the old and new * locations of the piece's anchor. */ if (ui->drag_anchor != ui->drag_currpos) { sprintf(data, "M%d-%d", ui->drag_anchor, ui->drag_currpos); str = dupstr(data); } else str = ""; /* null move; just update the UI */ ui->dragging = false; ui->drag_anchor = ui->drag_currpos = -1; ui->drag_offset_x = ui->drag_offset_y = -1; memset(ui->reachable, 0, wh * sizeof(bool)); return str; } else if (button == ' ' && state->soln) { /* * Make the next move in the stored solution. */ char data[256]; int a1, a2; a1 = state->soln->moves[state->soln_index*2]; a2 = state->soln->moves[state->soln_index*2+1]; if (a1 == state->lastmoved_pos) a1 = state->lastmoved; sprintf(data, "M%d-%d", a1, a2); return dupstr(data); } return NULL; } static bool move_piece(int w, int h, const unsigned char *src, unsigned char *dst, bool *ff, int from, int to) { int wh = w*h; int i, j; if (!ISANCHOR(dst[from])) return false; /* * Scan to the far end of the piece's linked list. */ for (i = j = from; j < wh; j++) if (src[j] == DIST(j - i)) i = j; /* * Remove the piece from its old location in the new * game state. */ for (j = i; j >= 0; j = (ISDIST(src[j]) ? j - src[j] : -1)) dst[j] = EMPTY; /* * And put it back in at the new location. */ for (j = i; j >= 0; j = (ISDIST(src[j]) ? j - src[j] : -1)) { int jn = j + to - from; if (jn < 0 || jn >= wh) return false; if (dst[jn] == EMPTY && (!ff[jn] || src[from] == MAINANCHOR)) { dst[jn] = src[j]; } else { return false; } } return true; } static game_state *execute_move(const game_state *state, const char *move) { int w = state->w, h = state->h /* , wh = w*h */; char c; int a1, a2, n, movesize; game_state *ret = dup_game(state); while (*move) { c = *move; if (c == 'S') { /* * This is a solve move, so we just set up a stored * solution path. */ if (ret->soln && --ret->soln->refcount <= 0) { sfree(ret->soln->moves); sfree(ret->soln); } ret->soln = snew(struct game_solution); ret->soln->nmoves = 0; ret->soln->moves = NULL; ret->soln->refcount = 1; ret->soln_index = 0; ret->cheated = true; movesize = 0; move++; while (1) { if (sscanf(move, "%d-%d%n", &a1, &a2, &n) != 2) { free_game(ret); return NULL; } /* * Special case: if the first move in the solution * involves the piece for which we already have a * partial stored move, adjust the source point to * the original starting point of that piece. */ if (ret->soln->nmoves == 0 && a1 == ret->lastmoved) a1 = ret->lastmoved_pos; if (ret->soln->nmoves >= movesize) { movesize = (ret->soln->nmoves + 48) * 4 / 3; ret->soln->moves = sresize(ret->soln->moves, 2*movesize, int); } ret->soln->moves[2*ret->soln->nmoves] = a1; ret->soln->moves[2*ret->soln->nmoves+1] = a2; ret->soln->nmoves++; move += n; if (*move != ',') break; move++; /* eat comma */ } } else if (c == 'M') { move++; if (sscanf(move, "%d-%d%n", &a1, &a2, &n) != 2 || !move_piece(w, h, state->board, ret->board, state->imm->forcefield, a1, a2)) { free_game(ret); return NULL; } if (a1 == ret->lastmoved) { /* * If the player has moved the same piece as they * moved last time, don't increment the move * count. In fact, if they've put the piece back * where it started from, _decrement_ the move * count. */ if (a2 == ret->lastmoved_pos) { ret->movecount--; /* reverted last move */ ret->lastmoved = ret->lastmoved_pos = -1; } else { ret->lastmoved = a2; /* don't change lastmoved_pos */ } } else { ret->lastmoved = a2; ret->lastmoved_pos = a1; ret->movecount++; } /* * If we have a stored solution path, see if we've * strayed from it or successfully made the next move * along it. */ if (ret->soln && ret->lastmoved_pos >= 0) { if (ret->lastmoved_pos != ret->soln->moves[ret->soln_index*2]) { /* strayed from the path */ ret->soln->refcount--; assert(ret->soln->refcount > 0); /* `state' at least still exists */ ret->soln = NULL; ret->soln_index = -1; } else if (ret->lastmoved == ret->soln->moves[ret->soln_index*2+1]) { /* advanced along the path */ ret->soln_index++; if (ret->soln_index >= ret->soln->nmoves) { /* finished the path! */ ret->soln->refcount--; assert(ret->soln->refcount > 0); /* `state' at least still exists */ ret->soln = NULL; ret->soln_index = -1; } } } if (ret->board[a2] == MAINANCHOR && a2 == ret->ty * w + ret->tx && ret->completed < 0) ret->completed = ret->movecount; move += n; } else { free_game(ret); return NULL; } if (*move == ';') move++; else if (*move) { free_game(ret); return NULL; } } return ret; } /* ---------------------------------------------------------------------- * Drawing routines. */ static void game_compute_size(const game_params *params, int tilesize, int *x, int *y) { /* fool the macros */ struct dummy { int tilesize; } dummy, *ds = &dummy; dummy.tilesize = tilesize; *x = params->w * TILESIZE + 2*BORDER; *y = params->h * TILESIZE + 2*BORDER; } static void game_set_size(drawing *dr, game_drawstate *ds, const game_params *params, int tilesize) { ds->tilesize = tilesize; } static void raise_colour(float *target, float *src, float *limit) { int i; for (i = 0; i < 3; i++) target[i] = (2*src[i] + limit[i]) / 3; } static float *game_colours(frontend *fe, int *ncolours) { float *ret = snewn(3 * NCOLOURS, float); game_mkhighlight(fe, ret, COL_BACKGROUND, COL_HIGHLIGHT, COL_LOWLIGHT); /* * When dragging a tile, we light it up a bit. */ raise_colour(ret+3*COL_DRAGGING, ret+3*COL_BACKGROUND, ret+3*COL_HIGHLIGHT); raise_colour(ret+3*COL_DRAGGING_HIGHLIGHT, ret+3*COL_HIGHLIGHT, ret+3*COL_HIGHLIGHT); raise_colour(ret+3*COL_DRAGGING_LOWLIGHT, ret+3*COL_LOWLIGHT, ret+3*COL_HIGHLIGHT); /* * The main tile is tinted blue. */ ret[COL_MAIN * 3 + 0] = ret[COL_BACKGROUND * 3 + 0]; ret[COL_MAIN * 3 + 1] = ret[COL_BACKGROUND * 3 + 1]; ret[COL_MAIN * 3 + 2] = ret[COL_HIGHLIGHT * 3 + 2]; game_mkhighlight_specific(fe, ret, COL_MAIN, COL_MAIN_HIGHLIGHT, COL_MAIN_LOWLIGHT); /* * And we light that up a bit too when dragging. */ raise_colour(ret+3*COL_MAIN_DRAGGING, ret+3*COL_MAIN, ret+3*COL_MAIN_HIGHLIGHT); raise_colour(ret+3*COL_MAIN_DRAGGING_HIGHLIGHT, ret+3*COL_MAIN_HIGHLIGHT, ret+3*COL_MAIN_HIGHLIGHT); raise_colour(ret+3*COL_MAIN_DRAGGING_LOWLIGHT, ret+3*COL_MAIN_LOWLIGHT, ret+3*COL_MAIN_HIGHLIGHT); /* * The target area on the floor is tinted green. */ ret[COL_TARGET * 3 + 0] = ret[COL_BACKGROUND * 3 + 0]; ret[COL_TARGET * 3 + 1] = ret[COL_HIGHLIGHT * 3 + 1]; ret[COL_TARGET * 3 + 2] = ret[COL_BACKGROUND * 3 + 2]; game_mkhighlight_specific(fe, ret, COL_TARGET, COL_TARGET_HIGHLIGHT, COL_TARGET_LOWLIGHT); *ncolours = NCOLOURS; return ret; } static game_drawstate *game_new_drawstate(drawing *dr, const game_state *state) { int w = state->w, h = state->h, wh = w*h; struct game_drawstate *ds = snew(struct game_drawstate); int i; ds->tilesize = 0; ds->w = w; ds->h = h; ds->started = false; ds->grid = snewn(wh, unsigned long); for (i = 0; i < wh; i++) ds->grid[i] = ~(unsigned long)0; return ds; } static void game_free_drawstate(drawing *dr, game_drawstate *ds) { sfree(ds->grid); sfree(ds); } #define BG_NORMAL 0x00000001UL #define BG_TARGET 0x00000002UL #define BG_FORCEFIELD 0x00000004UL #define FLASH_LOW 0x00000008UL #define FLASH_HIGH 0x00000010UL #define FG_WALL 0x00000020UL #define FG_MAIN 0x00000040UL #define FG_NORMAL 0x00000080UL #define FG_DRAGGING 0x00000100UL #define FG_SHADOW 0x00000200UL #define FG_SOLVEPIECE 0x00000400UL #define FG_MAINPIECESH 11 #define FG_SHADOWSH 19 #define PIECE_LBORDER 0x00000001UL #define PIECE_TBORDER 0x00000002UL #define PIECE_RBORDER 0x00000004UL #define PIECE_BBORDER 0x00000008UL #define PIECE_TLCORNER 0x00000010UL #define PIECE_TRCORNER 0x00000020UL #define PIECE_BLCORNER 0x00000040UL #define PIECE_BRCORNER 0x00000080UL #define PIECE_MASK 0x000000FFUL /* * Utility function. */ #define TYPE_MASK 0xF000 #define COL_MASK 0x0FFF #define TYPE_RECT 0x0000 #define TYPE_TLCIRC 0x4000 #define TYPE_TRCIRC 0x5000 #define TYPE_BLCIRC 0x6000 #define TYPE_BRCIRC 0x7000 static void maybe_rect(drawing *dr, int x, int y, int w, int h, int coltype, int col2) { int colour = coltype & COL_MASK, type = coltype & TYPE_MASK; if (colour > NCOLOURS) return; if (type == TYPE_RECT) { draw_rect(dr, x, y, w, h, colour); } else { int cx, cy, r; clip(dr, x, y, w, h); cx = x; cy = y; r = w-1; if (type & 0x1000) cx += r; if (type & 0x2000) cy += r; if (col2 == -1 || col2 == coltype) { assert(w == h); draw_circle(dr, cx, cy, r, colour, colour); } else { /* * We aim to draw a quadrant of a circle in two * different colours. We do this using Bresenham's * algorithm directly, because the Puzzles drawing API * doesn't have a draw-sector primitive. */ int bx, by, bd, bd2; int xm = (type & 0x1000 ? -1 : +1); int ym = (type & 0x2000 ? -1 : +1); by = r; bx = 0; bd = 0; while (by >= bx) { /* * Plot the point. */ { int x1 = cx+xm*bx, y1 = cy+ym*bx; int x2, y2; x2 = cx+xm*by; y2 = y1; draw_rect(dr, min(x1,x2), min(y1,y2), abs(x1-x2)+1, abs(y1-y2)+1, colour); x2 = x1; y2 = cy+ym*by; draw_rect(dr, min(x1,x2), min(y1,y2), abs(x1-x2)+1, abs(y1-y2)+1, col2); } bd += 2*bx + 1; bd2 = bd - (2*by - 1); if (abs(bd2) < abs(bd)) { bd = bd2; by--; } bx++; } } unclip(dr); } } static void draw_wallpart(drawing *dr, game_drawstate *ds, int tx, int ty, unsigned long val, int cl, int cc, int ch) { int coords[6]; draw_rect(dr, tx, ty, TILESIZE, TILESIZE, cc); if (val & PIECE_LBORDER) draw_rect(dr, tx, ty, HIGHLIGHT_WIDTH, TILESIZE, ch); if (val & PIECE_RBORDER) draw_rect(dr, tx+TILESIZE-HIGHLIGHT_WIDTH, ty, HIGHLIGHT_WIDTH, TILESIZE, cl); if (val & PIECE_TBORDER) draw_rect(dr, tx, ty, TILESIZE, HIGHLIGHT_WIDTH, ch); if (val & PIECE_BBORDER) draw_rect(dr, tx, ty+TILESIZE-HIGHLIGHT_WIDTH, TILESIZE, HIGHLIGHT_WIDTH, cl); if (!((PIECE_BBORDER | PIECE_LBORDER) &~ val)) { draw_rect(dr, tx, ty+TILESIZE-HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH, cl); clip(dr, tx, ty+TILESIZE-HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH); coords[0] = tx - 1; coords[1] = ty + TILESIZE - HIGHLIGHT_WIDTH - 1; coords[2] = tx + HIGHLIGHT_WIDTH; coords[3] = ty + TILESIZE - HIGHLIGHT_WIDTH - 1; coords[4] = tx - 1; coords[5] = ty + TILESIZE; draw_polygon(dr, coords, 3, ch, ch); unclip(dr); } else if (val & PIECE_BLCORNER) { draw_rect(dr, tx, ty+TILESIZE-HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH, ch); clip(dr, tx, ty+TILESIZE-HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH); coords[0] = tx - 1; coords[1] = ty + TILESIZE - HIGHLIGHT_WIDTH - 1; coords[2] = tx + HIGHLIGHT_WIDTH; coords[3] = ty + TILESIZE - HIGHLIGHT_WIDTH - 1; coords[4] = tx - 1; coords[5] = ty + TILESIZE; draw_polygon(dr, coords, 3, cl, cl); unclip(dr); } if (!((PIECE_TBORDER | PIECE_RBORDER) &~ val)) { draw_rect(dr, tx+TILESIZE-HIGHLIGHT_WIDTH, ty, HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH, cl); clip(dr, tx+TILESIZE-HIGHLIGHT_WIDTH, ty, HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH); coords[0] = tx + TILESIZE - HIGHLIGHT_WIDTH - 1; coords[1] = ty - 1; coords[2] = tx + TILESIZE; coords[3] = ty - 1; coords[4] = tx + TILESIZE - HIGHLIGHT_WIDTH - 1; coords[5] = ty + HIGHLIGHT_WIDTH; draw_polygon(dr, coords, 3, ch, ch); unclip(dr); } else if (val & PIECE_TRCORNER) { draw_rect(dr, tx+TILESIZE-HIGHLIGHT_WIDTH, ty, HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH, ch); clip(dr, tx+TILESIZE-HIGHLIGHT_WIDTH, ty, HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH); coords[0] = tx + TILESIZE - HIGHLIGHT_WIDTH - 1; coords[1] = ty - 1; coords[2] = tx + TILESIZE; coords[3] = ty - 1; coords[4] = tx + TILESIZE - HIGHLIGHT_WIDTH - 1; coords[5] = ty + HIGHLIGHT_WIDTH; draw_polygon(dr, coords, 3, cl, cl); unclip(dr); } if (val & PIECE_TLCORNER) draw_rect(dr, tx, ty, HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH, ch); if (val & PIECE_BRCORNER) draw_rect(dr, tx+TILESIZE-HIGHLIGHT_WIDTH, ty+TILESIZE-HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH, cl); } static void draw_piecepart(drawing *dr, game_drawstate *ds, int tx, int ty, unsigned long val, int cl, int cc, int ch) { int x[6], y[6]; /* * Drawing the blocks is hellishly fiddly. The blocks don't * stretch to the full size of the tile; there's a border * around them of size BORDER_WIDTH. Then they have bevelled * borders of size HIGHLIGHT_WIDTH, and also rounded corners. * * I tried for some time to find a clean and clever way to * figure out what needed drawing from the corner and border * flags, but in the end the cleanest way I could find was the * following. We divide the grid square into 25 parts by * ruling four horizontal and four vertical lines across it; * those lines are at BORDER_WIDTH and BORDER_WIDTH + * HIGHLIGHT_WIDTH from the top, from the bottom, from the * left and from the right. Then we carefully consider each of * the resulting 25 sections of square, and decide separately * what needs to go in it based on the flags. In complicated * cases there can be up to five possibilities affecting any * given section (no corner or border flags, just the corner * flag, one border flag, the other border flag, both border * flags). So there's a lot of very fiddly logic here and all * I could really think to do was give it my best shot and * then test it and correct all the typos. Not fun to write, * and I'm sure it isn't fun to read either, but it seems to * work. */ x[0] = tx; x[1] = x[0] + BORDER_WIDTH; x[2] = x[1] + HIGHLIGHT_WIDTH; x[5] = tx + TILESIZE; x[4] = x[5] - BORDER_WIDTH; x[3] = x[4] - HIGHLIGHT_WIDTH; y[0] = ty; y[1] = y[0] + BORDER_WIDTH; y[2] = y[1] + HIGHLIGHT_WIDTH; y[5] = ty + TILESIZE; y[4] = y[5] - BORDER_WIDTH; y[3] = y[4] - HIGHLIGHT_WIDTH; #define RECT(p,q) x[p], y[q], x[(p)+1]-x[p], y[(q)+1]-y[q] maybe_rect(dr, RECT(0,0), (val & (PIECE_TLCORNER | PIECE_TBORDER | PIECE_LBORDER)) ? -1 : cc, -1); maybe_rect(dr, RECT(1,0), (val & PIECE_TLCORNER) ? ch : (val & PIECE_TBORDER) ? -1 : (val & PIECE_LBORDER) ? ch : cc, -1); maybe_rect(dr, RECT(2,0), (val & PIECE_TBORDER) ? -1 : cc, -1); maybe_rect(dr, RECT(3,0), (val & PIECE_TRCORNER) ? cl : (val & PIECE_TBORDER) ? -1 : (val & PIECE_RBORDER) ? cl : cc, -1); maybe_rect(dr, RECT(4,0), (val & (PIECE_TRCORNER | PIECE_TBORDER | PIECE_RBORDER)) ? -1 : cc, -1); maybe_rect(dr, RECT(0,1), (val & PIECE_TLCORNER) ? ch : (val & PIECE_LBORDER) ? -1 : (val & PIECE_TBORDER) ? ch : cc, -1); maybe_rect(dr, RECT(1,1), (val & PIECE_TLCORNER) ? cc : -1, -1); maybe_rect(dr, RECT(1,1), (val & PIECE_TLCORNER) ? ch | TYPE_TLCIRC : !((PIECE_TBORDER | PIECE_LBORDER) &~ val) ? ch | TYPE_BRCIRC : (val & (PIECE_TBORDER | PIECE_LBORDER)) ? ch : cc, -1); maybe_rect(dr, RECT(2,1), (val & PIECE_TBORDER) ? ch : cc, -1); maybe_rect(dr, RECT(3,1), (val & PIECE_TRCORNER) ? cc : -1, -1); maybe_rect(dr, RECT(3,1), (val & (PIECE_TBORDER | PIECE_RBORDER)) == PIECE_TBORDER ? ch : (val & (PIECE_TBORDER | PIECE_RBORDER)) == PIECE_RBORDER ? cl : !((PIECE_TBORDER|PIECE_RBORDER) &~ val) ? cl | TYPE_BLCIRC : (val & PIECE_TRCORNER) ? cl | TYPE_TRCIRC : cc, ch); maybe_rect(dr, RECT(4,1), (val & PIECE_TRCORNER) ? ch : (val & PIECE_RBORDER) ? -1 : (val & PIECE_TBORDER) ? ch : cc, -1); maybe_rect(dr, RECT(0,2), (val & PIECE_LBORDER) ? -1 : cc, -1); maybe_rect(dr, RECT(1,2), (val & PIECE_LBORDER) ? ch : cc, -1); maybe_rect(dr, RECT(2,2), cc, -1); maybe_rect(dr, RECT(3,2), (val & PIECE_RBORDER) ? cl : cc, -1); maybe_rect(dr, RECT(4,2), (val & PIECE_RBORDER) ? -1 : cc, -1); maybe_rect(dr, RECT(0,3), (val & PIECE_BLCORNER) ? cl : (val & PIECE_LBORDER) ? -1 : (val & PIECE_BBORDER) ? cl : cc, -1); maybe_rect(dr, RECT(1,3), (val & PIECE_BLCORNER) ? cc : -1, -1); maybe_rect(dr, RECT(1,3), (val & (PIECE_BBORDER | PIECE_LBORDER)) == PIECE_BBORDER ? cl : (val & (PIECE_BBORDER | PIECE_LBORDER)) == PIECE_LBORDER ? ch : !((PIECE_BBORDER|PIECE_LBORDER) &~ val) ? ch | TYPE_TRCIRC : (val & PIECE_BLCORNER) ? ch | TYPE_BLCIRC : cc, cl); maybe_rect(dr, RECT(2,3), (val & PIECE_BBORDER) ? cl : cc, -1); maybe_rect(dr, RECT(3,3), (val & PIECE_BRCORNER) ? cc : -1, -1); maybe_rect(dr, RECT(3,3), (val & PIECE_BRCORNER) ? cl | TYPE_BRCIRC : !((PIECE_BBORDER | PIECE_RBORDER) &~ val) ? cl | TYPE_TLCIRC : (val & (PIECE_BBORDER | PIECE_RBORDER)) ? cl : cc, -1); maybe_rect(dr, RECT(4,3), (val & PIECE_BRCORNER) ? cl : (val & PIECE_RBORDER) ? -1 : (val & PIECE_BBORDER) ? cl : cc, -1); maybe_rect(dr, RECT(0,4), (val & (PIECE_BLCORNER | PIECE_BBORDER | PIECE_LBORDER)) ? -1 : cc, -1); maybe_rect(dr, RECT(1,4), (val & PIECE_BLCORNER) ? ch : (val & PIECE_BBORDER) ? -1 : (val & PIECE_LBORDER) ? ch : cc, -1); maybe_rect(dr, RECT(2,4), (val & PIECE_BBORDER) ? -1 : cc, -1); maybe_rect(dr, RECT(3,4), (val & PIECE_BRCORNER) ? cl : (val & PIECE_BBORDER) ? -1 : (val & PIECE_RBORDER) ? cl : cc, -1); maybe_rect(dr, RECT(4,4), (val & (PIECE_BRCORNER | PIECE_BBORDER | PIECE_RBORDER)) ? -1 : cc, -1); #undef RECT } static void draw_tile(drawing *dr, game_drawstate *ds, int x, int y, unsigned long val) { int tx = COORD(x), ty = COORD(y); int cc, ch, cl; /* * Draw the tile background. */ if (val & BG_TARGET) cc = COL_TARGET; else cc = COL_BACKGROUND; ch = cc+1; cl = cc+2; if (val & FLASH_LOW) cc = cl; else if (val & FLASH_HIGH) cc = ch; draw_rect(dr, tx, ty, TILESIZE, TILESIZE, cc); if (val & BG_FORCEFIELD) { /* * Cattle-grid effect to indicate that nothing but the * main block can slide over this square. */ int n = 3 * (TILESIZE / (3*HIGHLIGHT_WIDTH)); int i; for (i = 1; i < n; i += 3) { draw_rect(dr, tx,ty+(TILESIZE*i/n), TILESIZE,HIGHLIGHT_WIDTH, cl); draw_rect(dr, tx+(TILESIZE*i/n),ty, HIGHLIGHT_WIDTH,TILESIZE, cl); } } /* * Draw the tile midground: a shadow of a block, for * displaying partial solutions. */ if (val & FG_SHADOW) { draw_piecepart(dr, ds, tx, ty, (val >> FG_SHADOWSH) & PIECE_MASK, cl, cl, cl); } /* * Draw the tile foreground, i.e. some section of a block or * wall. */ if (val & FG_WALL) { cc = COL_BACKGROUND; ch = cc+1; cl = cc+2; if (val & FLASH_LOW) cc = cl; else if (val & FLASH_HIGH) cc = ch; draw_wallpart(dr, ds, tx, ty, (val >> FG_MAINPIECESH) & PIECE_MASK, cl, cc, ch); } else if (val & (FG_MAIN | FG_NORMAL)) { if (val & FG_DRAGGING) cc = (val & FG_MAIN ? COL_MAIN_DRAGGING : COL_DRAGGING); else cc = (val & FG_MAIN ? COL_MAIN : COL_BACKGROUND); ch = cc+1; cl = cc+2; if (val & FLASH_LOW) cc = cl; else if (val & (FLASH_HIGH | FG_SOLVEPIECE)) cc = ch; draw_piecepart(dr, ds, tx, ty, (val >> FG_MAINPIECESH) & PIECE_MASK, cl, cc, ch); } draw_update(dr, tx, ty, TILESIZE, TILESIZE); } static unsigned long find_piecepart(int w, int h, int *dsf, int x, int y) { int i = y*w+x; int canon = dsf_canonify(dsf, i); unsigned long val = 0; if (x == 0 || canon != dsf_canonify(dsf, i-1)) val |= PIECE_LBORDER; if (y== 0 || canon != dsf_canonify(dsf, i-w)) val |= PIECE_TBORDER; if (x == w-1 || canon != dsf_canonify(dsf, i+1)) val |= PIECE_RBORDER; if (y == h-1 || canon != dsf_canonify(dsf, i+w)) val |= PIECE_BBORDER; if (!(val & (PIECE_TBORDER | PIECE_LBORDER)) && canon != dsf_canonify(dsf, i-1-w)) val |= PIECE_TLCORNER; if (!(val & (PIECE_TBORDER | PIECE_RBORDER)) && canon != dsf_canonify(dsf, i+1-w)) val |= PIECE_TRCORNER; if (!(val & (PIECE_BBORDER | PIECE_LBORDER)) && canon != dsf_canonify(dsf, i-1+w)) val |= PIECE_BLCORNER; if (!(val & (PIECE_BBORDER | PIECE_RBORDER)) && canon != dsf_canonify(dsf, i+1+w)) val |= PIECE_BRCORNER; return val; } static void game_redraw(drawing *dr, game_drawstate *ds, const game_state *oldstate, const game_state *state, int dir, const game_ui *ui, float animtime, float flashtime) { int w = state->w, h = state->h, wh = w*h; unsigned char *board; int *dsf; int x, y, mainanchor, mainpos, dragpos, solvepos, solvesrc, solvedst; if (!ds->started) { /* * The initial contents of the window are not guaranteed * and can vary with front ends. To be on the safe side, * all games should start by drawing a big * background-colour rectangle covering the whole window. */ draw_rect(dr, 0, 0, 10*ds->tilesize, 10*ds->tilesize, COL_BACKGROUND); ds->started = true; } /* * Construct the board we'll be displaying (which may be * different from the one in state if ui describes a drag in * progress). */ board = snewn(wh, unsigned char); memcpy(board, state->board, wh); if (ui->dragging) { bool mpret = move_piece(w, h, state->board, board, state->imm->forcefield, ui->drag_anchor, ui->drag_currpos); assert(mpret); } if (state->soln) { solvesrc = state->soln->moves[state->soln_index*2]; solvedst = state->soln->moves[state->soln_index*2+1]; if (solvesrc == state->lastmoved_pos) solvesrc = state->lastmoved; if (solvesrc == ui->drag_anchor) solvesrc = ui->drag_currpos; } else solvesrc = solvedst = -1; /* * Build a dsf out of that board, so we can conveniently tell * which edges are connected and which aren't. */ dsf = snew_dsf(wh); mainanchor = -1; for (y = 0; y < h; y++) for (x = 0; x < w; x++) { int i = y*w+x; if (ISDIST(board[i])) dsf_merge(dsf, i, i - board[i]); if (board[i] == MAINANCHOR) mainanchor = i; if (board[i] == WALL) { if (x > 0 && board[i-1] == WALL) dsf_merge(dsf, i, i-1); if (y > 0 && board[i-w] == WALL) dsf_merge(dsf, i, i-w); } } assert(mainanchor >= 0); mainpos = dsf_canonify(dsf, mainanchor); dragpos = ui->drag_currpos > 0 ? dsf_canonify(dsf, ui->drag_currpos) : -1; solvepos = solvesrc >= 0 ? dsf_canonify(dsf, solvesrc) : -1; /* * Now we can construct the data about what we want to draw. */ for (y = 0; y < h; y++) for (x = 0; x < w; x++) { int i = y*w+x; int j; unsigned long val; int canon; /* * See if this square is part of the target area. */ j = i + mainanchor - (state->ty * w + state->tx); while (j >= 0 && j < wh && ISDIST(board[j])) j -= board[j]; if (j == mainanchor) val = BG_TARGET; else val = BG_NORMAL; if (state->imm->forcefield[i]) val |= BG_FORCEFIELD; if (flashtime > 0) { int flashtype = (int)(flashtime / FLASH_INTERVAL) & 1; val |= (flashtype ? FLASH_LOW : FLASH_HIGH); } if (board[i] != EMPTY) { canon = dsf_canonify(dsf, i); if (board[i] == WALL) val |= FG_WALL; else if (canon == mainpos) val |= FG_MAIN; else val |= FG_NORMAL; if (canon == dragpos) val |= FG_DRAGGING; if (canon == solvepos) val |= FG_SOLVEPIECE; /* * Now look around to see if other squares * belonging to the same block are adjacent to us. */ val |= find_piecepart(w, h, dsf, x, y) << FG_MAINPIECESH; } /* * If we're in the middle of showing a solution, * display a shadow piece for the target of the * current move. */ if (solvepos >= 0) { int si = i - solvedst + solvesrc; if (si >= 0 && si < wh && dsf_canonify(dsf, si) == solvepos) { val |= find_piecepart(w, h, dsf, si % w, si / w) << FG_SHADOWSH; val |= FG_SHADOW; } } if (val != ds->grid[i]) { draw_tile(dr, ds, x, y, val); ds->grid[i] = val; } } /* * Update the status bar. */ { char statusbuf[256]; sprintf(statusbuf, "%sMoves: %d", (state->completed >= 0 ? (state->cheated ? "Auto-solved. " : "COMPLETED! ") : (state->cheated ? "Auto-solver used. " : "")), (state->completed >= 0 ? state->completed : state->movecount)); if (state->minmoves >= 0) sprintf(statusbuf+strlen(statusbuf), " (min %d)", state->minmoves); status_bar(dr, statusbuf); } sfree(dsf); sfree(board); } static float game_anim_length(const game_state *oldstate, const game_state *newstate, int dir, game_ui *ui) { return 0.0F; } static float game_flash_length(const game_state *oldstate, const game_state *newstate, int dir, game_ui *ui) { if (oldstate->completed < 0 && newstate->completed >= 0) return FLASH_TIME; return 0.0F; } static int game_status(const game_state *state) { return state->completed ? +1 : 0; } static bool game_timing_state(const game_state *state, game_ui *ui) { return true; } static void game_print_size(const game_params *params, float *x, float *y) { } static void game_print(drawing *dr, const game_state *state, int tilesize) { } #ifdef COMBINED #define thegame slide #endif const struct game thegame = { "Slide", NULL, NULL, default_params, game_fetch_preset, NULL, decode_params, encode_params, free_params, dup_params, true, game_configure, custom_params, validate_params, new_game_desc, validate_desc, new_game, dup_game, free_game, true, solve_game, true, game_can_format_as_text_now, game_text_format, new_ui, free_ui, encode_ui, decode_ui, NULL, /* game_request_keys */ game_changed_state, interpret_move, execute_move, PREFERRED_TILESIZE, game_compute_size, game_set_size, game_colours, game_new_drawstate, game_free_drawstate, game_redraw, game_anim_length, game_flash_length, game_status, false, false, game_print_size, game_print, true, /* wants_statusbar */ false, game_timing_state, 0, /* flags */ }; #ifdef STANDALONE_SOLVER #include <stdarg.h> int main(int argc, char **argv) { game_params *p; game_state *s; char *id = NULL, *desc; const char *err; bool count = false; int ret; int *moves; while (--argc > 0) { char *p = *++argv; /* if (!strcmp(p, "-v")) { verbose = true; } else */ if (!strcmp(p, "-c")) { count = true; } else if (*p == '-') { fprintf(stderr, "%s: unrecognised option `%s'\n", argv[0], p); return 1; } else { id = p; } } if (!id) { fprintf(stderr, "usage: %s [-c | -v] <game_id>\n", argv[0]); return 1; } desc = strchr(id, ':'); if (!desc) { fprintf(stderr, "%s: game id expects a colon in it\n", argv[0]); return 1; } *desc++ = '\0'; p = default_params(); decode_params(p, id); err = validate_desc(p, desc); if (err) { fprintf(stderr, "%s: %s\n", argv[0], err); return 1; } s = new_game(NULL, p, desc); ret = solve_board(s->w, s->h, s->board, s->imm->forcefield, s->tx, s->ty, -1, &moves); if (ret < 0) { printf("No solution found\n"); } else { int index = 0; if (count) { printf("%d moves required\n", ret); return 0; } while (1) { bool moveret; char *text = board_text_format(s->w, s->h, s->board, s->imm->forcefield); game_state *s2; printf("position %d:\n%s", index, text); if (index >= ret) break; s2 = dup_game(s); moveret = move_piece(s->w, s->h, s->board, s2->board, s->imm->forcefield, moves[index*2], moves[index*2+1]); assert(moveret); free_game(s); s = s2; index++; } } return 0; } #endif