X-Git-Url: https://git.distorted.org.uk/~mdw/sgt/puzzles/blobdiff_plain/a36a26d73183965c4286f71ede896ccdbf8d5102..a15e5ee340857b4763cede846a3fa52915f278cb:/loopy.c diff --git a/loopy.c b/loopy.c index 5f3c601..e7fb6cb 100644 --- a/loopy.c +++ b/loopy.c @@ -73,6 +73,7 @@ #include #include +#include #include #include #include @@ -101,11 +102,12 @@ enum { COL_HIGHLIGHT, COL_MISTAKE, COL_SATISFIED, + COL_FAINT, NCOLOURS }; struct game_state { - grid *game_grid; + grid *game_grid; /* ref-counted (internally) */ /* Put -1 in a face that doesn't get a clue */ signed char *clues; @@ -114,6 +116,8 @@ struct game_state { * YES, NO or UNKNOWN */ char *lines; + unsigned char *line_errors; + int solved; int cheated; @@ -130,17 +134,6 @@ enum solver_status { }; /* ------ Solver state ------ */ -typedef struct normal { - /* For each dline, store a bitmask for whether we know: - * (bit 0) at least one is YES - * (bit 1) at most one is YES */ - char *dlines; -} normal_mode_state; - -typedef struct hard { - int *linedsf; -} hard_mode_state; - typedef struct solver_state { game_state *state; enum solver_status solver_status; @@ -148,6 +141,10 @@ typedef struct solver_state { * looplen of 1 means there are no lines to a particular dot */ int *looplen; + /* Difficulty level of solver. Used by solver functions that want to + * vary their behaviour depending on the requested difficulty level. */ + int diff; + /* caches */ char *dot_yes_count; char *dot_no_count; @@ -156,8 +153,14 @@ typedef struct solver_state { char *dot_solved, *face_solved; int *dotdsf; - normal_mode_state *normal; - hard_mode_state *hard; + /* Information for Normal level deductions: + * For each dline, store a bitmask for whether we know: + * (bit 0) at least one is YES + * (bit 1) at most one is YES */ + char *dlines; + + /* Hard level information */ + int *linedsf; } solver_state; /* @@ -166,33 +169,52 @@ typedef struct solver_state { */ #define DIFFLIST(A) \ - A(EASY,Easy,e,easy_mode_deductions) \ - A(NORMAL,Normal,n,normal_mode_deductions) \ - A(HARD,Hard,h,hard_mode_deductions) -#define ENUM(upper,title,lower,fn) DIFF_ ## upper, -#define TITLE(upper,title,lower,fn) #title, -#define ENCODE(upper,title,lower,fn) #lower -#define CONFIG(upper,title,lower,fn) ":" #title -#define SOLVER_FN_DECL(upper,title,lower,fn) static int fn(solver_state *); -#define SOLVER_FN(upper,title,lower,fn) &fn, + A(EASY,Easy,e) \ + A(NORMAL,Normal,n) \ + A(TRICKY,Tricky,t) \ + A(HARD,Hard,h) +#define ENUM(upper,title,lower) DIFF_ ## upper, +#define TITLE(upper,title,lower) #title, +#define ENCODE(upper,title,lower) #lower +#define CONFIG(upper,title,lower) ":" #title enum { DIFFLIST(ENUM) DIFF_MAX }; static char const *const diffnames[] = { DIFFLIST(TITLE) }; static char const diffchars[] = DIFFLIST(ENCODE); #define DIFFCONFIG DIFFLIST(CONFIG) -DIFFLIST(SOLVER_FN_DECL); -static int (*(solver_fns[]))(solver_state *) = { DIFFLIST(SOLVER_FN) }; + +/* + * Solver routines, sorted roughly in order of computational cost. + * The solver will run the faster deductions first, and slower deductions are + * only invoked when the faster deductions are unable to make progress. + * Each function is associated with a difficulty level, so that the generated + * puzzles are solvable by applying only the functions with the chosen + * difficulty level or lower. + */ +#define SOLVERLIST(A) \ + A(trivial_deductions, DIFF_EASY) \ + A(dline_deductions, DIFF_NORMAL) \ + A(linedsf_deductions, DIFF_HARD) \ + A(loop_deductions, DIFF_EASY) +#define SOLVER_FN_DECL(fn,diff) static int fn(solver_state *); +#define SOLVER_FN(fn,diff) &fn, +#define SOLVER_DIFF(fn,diff) diff, +SOLVERLIST(SOLVER_FN_DECL) +static int (*(solver_fns[]))(solver_state *) = { SOLVERLIST(SOLVER_FN) }; +static int const solver_diffs[] = { SOLVERLIST(SOLVER_DIFF) }; +static const int NUM_SOLVERS = sizeof(solver_diffs)/sizeof(*solver_diffs); struct game_params { int w, h; int diff; int type; - - /* Grid generation is expensive, so keep a (ref-counted) reference to the - * grid for these parameters, and only generate when required. */ - grid *game_grid; }; +/* line_drawstate is the same as line_state, but with the extra ERROR + * possibility. The drawing code copies line_state to line_drawstate, + * except in the case that the line is an error. */ enum line_state { LINE_YES, LINE_UNKNOWN, LINE_NO }; +enum line_drawstate { DS_LINE_YES, DS_LINE_UNKNOWN, + DS_LINE_NO, DS_LINE_ERROR }; #define OPP(line_state) \ (2 - line_state) @@ -202,6 +224,7 @@ struct game_drawstate { int started; int tilesize; int flashing; + int *textx, *texty; char *lines; char *clue_error; char *clue_satisfied; @@ -210,8 +233,7 @@ struct game_drawstate { static char *validate_desc(game_params *params, char *desc); static int dot_order(const game_state* state, int i, char line_type); static int face_order(const game_state* state, int i, char line_type); -static solver_state *solve_game_rec(const solver_state *sstate, - int diff); +static solver_state *solve_game_rec(const solver_state *sstate); #ifdef DEBUG_CACHES static void check_caches(const solver_state* sstate); @@ -221,32 +243,42 @@ static void check_caches(const solver_state* sstate); /* ------- List of grid generators ------- */ #define GRIDLIST(A) \ - A(Squares,grid_new_square) \ - A(Triangular,grid_new_triangular) \ - A(Honeycomb,grid_new_honeycomb) \ - A(Snub-Square,grid_new_snubsquare) \ - A(Cairo,grid_new_cairo) \ - A(Great-Hexagonal,grid_new_greathexagonal) \ - A(Octagonal,grid_new_octagonal) \ - A(Kites,grid_new_kites) - -#define GRID_NAME(title,fn) #title, -#define GRID_CONFIG(title,fn) ":" #title -#define GRID_FN(title,fn) &fn, + A(Squares,GRID_SQUARE,3,3) \ + A(Triangular,GRID_TRIANGULAR,3,3) \ + A(Honeycomb,GRID_HONEYCOMB,3,3) \ + A(Snub-Square,GRID_SNUBSQUARE,3,3) \ + A(Cairo,GRID_CAIRO,3,4) \ + A(Great-Hexagonal,GRID_GREATHEXAGONAL,3,3) \ + A(Octagonal,GRID_OCTAGONAL,3,3) \ + A(Kites,GRID_KITE,3,3) \ + A(Floret,GRID_FLORET,1,2) \ + A(Dodecagonal,GRID_DODECAGONAL,2,2) \ + A(Great-Dodecagonal,GRID_GREATDODECAGONAL,2,2) \ + A(Penrose (kite/dart),GRID_PENROSE_P2,3,3) \ + A(Penrose (rhombs),GRID_PENROSE_P3,3,3) + +#define GRID_NAME(title,type,amin,omin) #title, +#define GRID_CONFIG(title,type,amin,omin) ":" #title +#define GRID_TYPE(title,type,amin,omin) type, +#define GRID_SIZES(title,type,amin,omin) \ + {amin, omin, \ + "Width and height for this grid type must both be at least " #amin, \ + "At least one of width and height for this grid type must be at least " #omin,}, static char const *const gridnames[] = { GRIDLIST(GRID_NAME) }; #define GRID_CONFIGS GRIDLIST(GRID_CONFIG) -static grid * (*(grid_fns[]))(int w, int h) = { GRIDLIST(GRID_FN) }; -static const int NUM_GRID_TYPES = sizeof(grid_fns) / sizeof(grid_fns[0]); +static grid_type grid_types[] = { GRIDLIST(GRID_TYPE) }; +#define NUM_GRID_TYPES (sizeof(grid_types) / sizeof(grid_types[0])) +static const struct { + int amin, omin; + char *aerr, *oerr; +} grid_size_limits[] = { GRIDLIST(GRID_SIZES) }; /* Generates a (dynamically allocated) new grid, according to the * type and size requested in params. Does nothing if the grid is already - * generated. The allocated grid is owned by the params object, and will be - * freed in free_params(). */ -static void params_generate_grid(game_params *params) + * generated. */ +static grid *loopy_generate_grid(game_params *params, char *grid_desc) { - if (!params->game_grid) { - params->game_grid = grid_fns[params->type](params->w, params->h); - } + return grid_new(grid_types[params->type], params->w, params->h, grid_desc); } /* ---------------------------------------------------------------------- @@ -267,7 +299,7 @@ static void params_generate_grid(game_params *params) ((field) &= ~(1<<(bit)), TRUE) : FALSE) #define CLUE2CHAR(c) \ - ((c < 0) ? ' ' : c + '0') + ((c < 0) ? ' ' : c < 10 ? c + '0' : c - 10 + 'A') /* ---------------------------------------------------------------------- * General struct manipulation and other straightforward code @@ -289,6 +321,9 @@ static game_state *dup_game(game_state *state) ret->lines = snewn(state->game_grid->num_edges, char); memcpy(ret->lines, state->lines, state->game_grid->num_edges); + ret->line_errors = snewn(state->game_grid->num_edges, unsigned char); + memcpy(ret->line_errors, state->line_errors, state->game_grid->num_edges); + ret->grid_type = state->grid_type; return ret; } @@ -299,6 +334,7 @@ static void free_game(game_state *state) grid_free(state->game_grid); sfree(state->clues); sfree(state->lines); + sfree(state->line_errors); sfree(state); } } @@ -313,6 +349,7 @@ static solver_state *new_solver_state(game_state *state, int diff) { ret->state = dup_game(state); ret->solver_status = SOLVER_INCOMPLETE; + ret->diff = diff; ret->dotdsf = snew_dsf(num_dots); ret->looplen = snewn(num_dots, int); @@ -336,18 +373,16 @@ static solver_state *new_solver_state(game_state *state, int diff) { memset(ret->face_no_count, 0, num_faces); if (diff < DIFF_NORMAL) { - ret->normal = NULL; + ret->dlines = NULL; } else { - ret->normal = snew(normal_mode_state); - ret->normal->dlines = snewn(2*num_edges, char); - memset(ret->normal->dlines, 0, 2*num_edges); + ret->dlines = snewn(2*num_edges, char); + memset(ret->dlines, 0, 2*num_edges); } if (diff < DIFF_HARD) { - ret->hard = NULL; + ret->linedsf = NULL; } else { - ret->hard = snew(hard_mode_state); - ret->hard->linedsf = snew_dsf(state->game_grid->num_edges); + ret->linedsf = snew_dsf(state->game_grid->num_edges); } return ret; @@ -365,15 +400,9 @@ static void free_solver_state(solver_state *sstate) { sfree(sstate->face_yes_count); sfree(sstate->face_no_count); - if (sstate->normal) { - sfree(sstate->normal->dlines); - sfree(sstate->normal); - } - - if (sstate->hard) { - sfree(sstate->hard->linedsf); - sfree(sstate->hard); - } + /* OK, because sfree(NULL) is a no-op */ + sfree(sstate->dlines); + sfree(sstate->linedsf); sfree(sstate); } @@ -389,6 +418,7 @@ static solver_state *dup_solver_state(const solver_state *sstate) { ret->state = state = dup_game(sstate->state); ret->solver_status = sstate->solver_status; + ret->diff = sstate->diff; ret->dotdsf = snewn(num_dots, int); ret->looplen = snewn(num_dots, int); @@ -412,22 +442,20 @@ static solver_state *dup_solver_state(const solver_state *sstate) { ret->face_no_count = snewn(num_faces, char); memcpy(ret->face_no_count, sstate->face_no_count, num_faces); - if (sstate->normal) { - ret->normal = snew(normal_mode_state); - ret->normal->dlines = snewn(2*num_edges, char); - memcpy(ret->normal->dlines, sstate->normal->dlines, + if (sstate->dlines) { + ret->dlines = snewn(2*num_edges, char); + memcpy(ret->dlines, sstate->dlines, 2*num_edges); } else { - ret->normal = NULL; + ret->dlines = NULL; } - if (sstate->hard) { - ret->hard = snew(hard_mode_state); - ret->hard->linedsf = snewn(num_edges, int); - memcpy(ret->hard->linedsf, sstate->hard->linedsf, + if (sstate->linedsf) { + ret->linedsf = snewn(num_edges, int); + memcpy(ret->linedsf, sstate->linedsf, num_edges * sizeof(int)); } else { - ret->hard = NULL; + ret->linedsf = NULL; } return ret; @@ -447,8 +475,6 @@ static game_params *default_params(void) ret->diff = DIFF_EASY; ret->type = 0; - ret->game_grid = NULL; - return ret; } @@ -457,26 +483,46 @@ static game_params *dup_params(game_params *params) game_params *ret = snew(game_params); *ret = *params; /* structure copy */ - if (ret->game_grid) { - ret->game_grid->refcount++; - } return ret; } static const game_params presets[] = { - { 7, 7, DIFF_EASY, 0, NULL }, - { 10, 10, DIFF_EASY, 0, NULL }, - { 7, 7, DIFF_NORMAL, 0, NULL }, - { 10, 10, DIFF_NORMAL, 0, NULL }, - { 7, 7, DIFF_HARD, 0, NULL }, - { 10, 10, DIFF_HARD, 0, NULL }, - { 10, 10, DIFF_HARD, 1, NULL }, - { 12, 10, DIFF_HARD, 2, NULL }, - { 7, 7, DIFF_HARD, 3, NULL }, - { 9, 9, DIFF_HARD, 4, NULL }, - { 5, 4, DIFF_HARD, 5, NULL }, - { 7, 7, DIFF_HARD, 6, NULL }, - { 5, 5, DIFF_HARD, 7, NULL }, +#ifdef SMALL_SCREEN + { 7, 7, DIFF_EASY, 0 }, + { 7, 7, DIFF_NORMAL, 0 }, + { 7, 7, DIFF_HARD, 0 }, + { 7, 7, DIFF_HARD, 1 }, + { 7, 7, DIFF_HARD, 2 }, + { 5, 5, DIFF_HARD, 3 }, + { 7, 7, DIFF_HARD, 4 }, + { 5, 4, DIFF_HARD, 5 }, + { 5, 5, DIFF_HARD, 6 }, + { 5, 5, DIFF_HARD, 7 }, + { 3, 3, DIFF_HARD, 8 }, + { 3, 3, DIFF_HARD, 9 }, + { 3, 3, DIFF_HARD, 10 }, + { 6, 6, DIFF_HARD, 11 }, + { 6, 6, DIFF_HARD, 12 }, +#else + { 7, 7, DIFF_EASY, 0 }, + { 10, 10, DIFF_EASY, 0 }, + { 7, 7, DIFF_NORMAL, 0 }, + { 10, 10, DIFF_NORMAL, 0 }, + { 7, 7, DIFF_HARD, 0 }, + { 10, 10, DIFF_HARD, 0 }, + { 10, 10, DIFF_HARD, 1 }, + { 12, 10, DIFF_HARD, 2 }, + { 7, 7, DIFF_HARD, 3 }, + { 9, 9, DIFF_HARD, 4 }, + { 5, 4, DIFF_HARD, 5 }, + { 7, 7, DIFF_HARD, 6 }, + { 5, 5, DIFF_HARD, 7 }, + { 5, 5, DIFF_HARD, 8 }, + { 5, 4, DIFF_HARD, 9 }, + { 5, 4, DIFF_HARD, 10 }, + { 10, 10, DIFF_HARD, 11 }, + { 10, 10, DIFF_HARD, 12 } +#endif }; static int game_fetch_preset(int i, char **name, game_params **params) @@ -499,18 +545,11 @@ static int game_fetch_preset(int i, char **name, game_params **params) static void free_params(game_params *params) { - if (params->game_grid) { - grid_free(params->game_grid); - } sfree(params); } static void decode_params(game_params *params, char const *string) { - if (params->game_grid) { - grid_free(params->game_grid); - params->game_grid = NULL; - } params->h = params->w = atoi(string); params->diff = DIFF_EASY; while (*string && isdigit((unsigned char)*string)) string++; @@ -589,16 +628,19 @@ static game_params *custom_params(config_item *cfg) ret->type = cfg[2].ival; ret->diff = cfg[3].ival; - ret->game_grid = NULL; return ret; } static char *validate_params(game_params *params, int full) { - if (params->w < 3 || params->h < 3) - return "Width and height must both be at least 3"; if (params->type < 0 || params->type >= NUM_GRID_TYPES) return "Illegal grid type"; + if (params->w < grid_size_limits[params->type].amin || + params->h < grid_size_limits[params->type].amin) + return grid_size_limits[params->type].aerr; + if (params->w < grid_size_limits[params->type].omin && + params->h < grid_size_limits[params->type].omin) + return grid_size_limits[params->type].oerr; /* * This shouldn't be able to happen at all, since decode_params @@ -646,17 +688,47 @@ static char *state_to_text(const game_state *state) return retval; } +#define GRID_DESC_SEP '_' + +/* Splits up a (optional) grid_desc from the game desc. Returns the + * grid_desc (which needs freeing) and updates the desc pointer to + * start of real desc, or returns NULL if no desc. */ +static char *extract_grid_desc(char **desc) +{ + char *sep = strchr(*desc, GRID_DESC_SEP), *gd; + int gd_len; + + if (!sep) return NULL; + + gd_len = sep - (*desc); + gd = snewn(gd_len+1, char); + memcpy(gd, *desc, gd_len); + gd[gd_len] = '\0'; + + *desc = sep+1; + + return gd; +} + /* We require that the params pass the test in validate_params and that the * description fills the entire game area */ static char *validate_desc(game_params *params, char *desc) { int count = 0; grid *g; - params_generate_grid(params); - g = params->game_grid; + char *grid_desc, *ret; + + /* It's pretty inefficient to do this just for validation. All we need to + * know is the precise number of faces. */ + grid_desc = extract_grid_desc(&desc); + ret = grid_validate_desc(grid_types[params->type], params->w, params->h, grid_desc); + if (ret) return ret; + + g = loopy_generate_grid(params, grid_desc); + if (grid_desc) sfree(grid_desc); for (; *desc; ++desc) { - if (*desc >= '0' && *desc <= '9') { + if ((*desc >= '0' && *desc <= '9') || (*desc >= 'A' && *desc <= 'Z')) { count++; continue; } @@ -672,6 +744,8 @@ static char *validate_desc(game_params *params, char *desc) if (count > g->num_faces) return "Description too long for board size"; + grid_free(g); + return NULL; } @@ -753,16 +827,15 @@ static void game_changed_state(game_ui *ui, game_state *oldstate, static void game_compute_size(game_params *params, int tilesize, int *x, int *y) { - grid *g; int grid_width, grid_height, rendered_width, rendered_height; + int g_tilesize; + + grid_compute_size(grid_types[params->type], params->w, params->h, + &g_tilesize, &grid_width, &grid_height); - params_generate_grid(params); - g = params->game_grid; - grid_width = g->highest_x - g->lowest_x; - grid_height = g->highest_y - g->lowest_y; /* multiply first to minimise rounding error on integer division */ - rendered_width = grid_width * tilesize / g->tilesize; - rendered_height = grid_height * tilesize / g->tilesize; + rendered_width = grid_width * tilesize / g_tilesize; + rendered_height = grid_height * tilesize / g_tilesize; *x = rendered_width + 2 * BORDER(tilesize) + 1; *y = rendered_height + 2 * BORDER(tilesize) + 1; } @@ -783,8 +856,14 @@ static float *game_colours(frontend *fe, int *ncolours) ret[COL_FOREGROUND * 3 + 1] = 0.0F; ret[COL_FOREGROUND * 3 + 2] = 0.0F; - ret[COL_LINEUNKNOWN * 3 + 0] = 0.8F; - ret[COL_LINEUNKNOWN * 3 + 1] = 0.8F; + /* + * We want COL_LINEUNKNOWN to be a yellow which is a bit darker + * than the background. (I previously set it to 0.8,0.8,0, but + * found that this went badly with the 0.8,0.8,0.8 favoured as a + * background by the Java frontend.) + */ + ret[COL_LINEUNKNOWN * 3 + 0] = ret[COL_BACKGROUND * 3 + 0] * 0.9F; + ret[COL_LINEUNKNOWN * 3 + 1] = ret[COL_BACKGROUND * 3 + 1] * 0.9F; ret[COL_LINEUNKNOWN * 3 + 2] = 0.0F; ret[COL_HIGHLIGHT * 3 + 0] = 1.0F; @@ -799,6 +878,14 @@ static float *game_colours(frontend *fe, int *ncolours) ret[COL_SATISFIED * 3 + 1] = 0.0F; ret[COL_SATISFIED * 3 + 2] = 0.0F; + /* We want the faint lines to be a bit darker than the background. + * Except if the background is pretty dark already; then it ought to be a + * bit lighter. Oy vey. + */ + ret[COL_FAINT * 3 + 0] = ret[COL_BACKGROUND * 3 + 0] * 0.9F; + ret[COL_FAINT * 3 + 1] = ret[COL_BACKGROUND * 3 + 1] * 0.9F; + ret[COL_FAINT * 3 + 2] = ret[COL_BACKGROUND * 3 + 2] * 0.9F; + *ncolours = NCOLOURS; return ret; } @@ -808,23 +895,30 @@ static game_drawstate *game_new_drawstate(drawing *dr, game_state *state) struct game_drawstate *ds = snew(struct game_drawstate); int num_faces = state->game_grid->num_faces; int num_edges = state->game_grid->num_edges; + int i; ds->tilesize = 0; ds->started = 0; ds->lines = snewn(num_edges, char); ds->clue_error = snewn(num_faces, char); ds->clue_satisfied = snewn(num_faces, char); + ds->textx = snewn(num_faces, int); + ds->texty = snewn(num_faces, int); ds->flashing = 0; memset(ds->lines, LINE_UNKNOWN, num_edges); memset(ds->clue_error, 0, num_faces); memset(ds->clue_satisfied, 0, num_faces); + for (i = 0; i < num_faces; i++) + ds->textx[i] = ds->texty[i] = -1; return ds; } static void game_free_drawstate(drawing *dr, game_drawstate *ds) { + sfree(ds->textx); + sfree(ds->texty); sfree(ds->clue_error); sfree(ds->clue_satisfied); sfree(ds->lines); @@ -1068,12 +1162,12 @@ static int merge_lines(solver_state *sstate, int i, int j, int inverse assert(i < sstate->state->game_grid->num_edges); assert(j < sstate->state->game_grid->num_edges); - i = edsf_canonify(sstate->hard->linedsf, i, &inv_tmp); + i = edsf_canonify(sstate->linedsf, i, &inv_tmp); inverse ^= inv_tmp; - j = edsf_canonify(sstate->hard->linedsf, j, &inv_tmp); + j = edsf_canonify(sstate->linedsf, j, &inv_tmp); inverse ^= inv_tmp; - edsf_merge(sstate->hard->linedsf, i, j, inverse); + edsf_merge(sstate->linedsf, i, j, inverse); #ifdef SHOW_WORKING if (i != j) { @@ -1183,33 +1277,34 @@ static int face_setall(solver_state *sstate, int face, * Loop generation and clue removal */ -/* We're going to store a list of current candidate faces for lighting. +/* We're going to store lists of current candidate faces for colouring black + * or white. * Each face gets a 'score', which tells us how adding that face right - * now would affect the length of the solution loop. We're trying to + * now would affect the curliness of the solution loop. We're trying to * maximise that quantity so will bias our random selection of faces to - * light towards those with high scores */ -struct face { - int score; + * colour those with high scores */ +struct face_score { + int white_score; + int black_score; unsigned long random; - grid_face *f; + /* No need to store a grid_face* here. The 'face_scores' array will + * be a list of 'face_score' objects, one for each face of the grid, so + * the position (index) within the 'face_scores' array will determine + * which face corresponds to a particular face_score. + * Having a single 'face_scores' array for all faces simplifies memory + * management, and probably improves performance, because we don't have to + * malloc/free each individual face_score, and we don't have to maintain + * a mapping from grid_face* pointers to face_score* pointers. + */ }; -static int get_face_cmpfn(void *v1, void *v2) -{ - struct face *f1 = v1; - struct face *f2 = v2; - /* These grid_face pointers always point into the same list of - * 'grid_face's, so it's valid to subtract them. */ - return f1->f - f2->f; -} - -static int face_sort_cmpfn(void *v1, void *v2) +static int generic_sort_cmpfn(void *v1, void *v2, size_t offset) { - struct face *f1 = v1; - struct face *f2 = v2; + struct face_score *f1 = v1; + struct face_score *f2 = v2; int r; - r = f2->score - f1->score; + r = *(int *)((char *)f2 + offset) - *(int *)((char *)f1 + offset); if (r) { return r; } @@ -1222,64 +1317,75 @@ static int face_sort_cmpfn(void *v1, void *v2) /* * It's _just_ possible that two faces might have been given * the same random value. In that situation, fall back to - * comparing based on the positions within the grid's face-list. + * comparing based on the positions within the face_scores list. * This introduces a tiny directional bias, but not a significant one. */ - return get_face_cmpfn(f1, f2); + return f1 - f2; } -enum { FACE_LIT, FACE_UNLIT }; +static int white_sort_cmpfn(void *v1, void *v2) +{ + return generic_sort_cmpfn(v1, v2, offsetof(struct face_score,white_score)); +} + +static int black_sort_cmpfn(void *v1, void *v2) +{ + return generic_sort_cmpfn(v1, v2, offsetof(struct face_score,black_score)); +} + +enum face_colour { FACE_WHITE, FACE_GREY, FACE_BLACK }; /* face should be of type grid_face* here. */ -#define FACE_LIT_STATE(face) \ - ( (face) == NULL ? FACE_UNLIT : \ +#define FACE_COLOUR(face) \ + ( (face) == NULL ? FACE_BLACK : \ board[(face) - g->faces] ) /* 'board' is an array of these enums, indicating which faces are - * currently lit. Returns whether it's legal to light up the - * given face. */ -static int can_light_face(grid *g, char* board, int face_index) + * currently black/white/grey. 'colour' is FACE_WHITE or FACE_BLACK. + * Returns whether it's legal to colour the given face with this colour. */ +static int can_colour_face(grid *g, char* board, int face_index, + enum face_colour colour) { int i, j; grid_face *test_face = g->faces + face_index; grid_face *starting_face, *current_face; + grid_dot *starting_dot; int transitions; - int current_state, s; - int found_lit_neighbour = FALSE; - assert(board[face_index] == FACE_UNLIT); + int current_state, s; /* booleans: equal or not-equal to 'colour' */ + int found_same_coloured_neighbour = FALSE; + assert(board[face_index] != colour); - /* Can only consider a face for lighting if it's adjacent to an - * already lit face. */ + /* Can only consider a face for colouring if it's adjacent to a face + * with the same colour. */ for (i = 0; i < test_face->order; i++) { grid_edge *e = test_face->edges[i]; grid_face *f = (e->face1 == test_face) ? e->face2 : e->face1; - if (FACE_LIT_STATE(f) == FACE_LIT) { - found_lit_neighbour = TRUE; + if (FACE_COLOUR(f) == colour) { + found_same_coloured_neighbour = TRUE; break; } } - if (!found_lit_neighbour) + if (!found_same_coloured_neighbour) return FALSE; - /* Need to avoid creating a loop of lit faces around some unlit faces. - * Also need to avoid meeting another lit face at a corner, with - * unlit faces in between. Here's a simple test that (I believe) takes - * care of both these conditions: + /* Need to avoid creating a loop of faces of this colour around some + * differently-coloured faces. + * Also need to avoid meeting a same-coloured face at a corner, with + * other-coloured faces in between. Here's a simple test that (I believe) + * takes care of both these conditions: * * Take the circular path formed by this face's edges, and inflate it * slightly outwards. Imagine walking around this path and consider * the faces that you visit in sequence. This will include all faces * touching the given face, either along an edge or just at a corner. - * Count the number of LIT/UNLIT transitions you encounter, as you walk - * along the complete loop. This will obviously turn out to be an even - * number. - * If 0, we're either in a completely unlit zone, or this face is a hole - * in a completely lit zone. If the former, we would create a brand new - * island by lighting this face. And the latter ought to be impossible - - * it would mean there's already a lit loop, so something went wrong - * earlier. - * If 4 or greater, there are too many separate lit regions touching this - * face, and lighting it up would create a loop or a corner-violation. + * Count the number of 'colour'/not-'colour' transitions you encounter, as + * you walk along the complete loop. This will obviously turn out to be + * an even number. + * If 0, we're either in the middle of an "island" of this colour (should + * be impossible as we're not supposed to create black or white loops), + * or we're about to start a new island - also not allowed. + * If 4 or greater, there are too many separate coloured regions touching + * this face, and colouring it would create a loop or a corner-violation. * The only allowed case is when the count is exactly 2. */ /* i points to a dot around the test face. @@ -1288,17 +1394,39 @@ static int can_light_face(grid *g, char* board, int face_index) * test_face->dots[i]->faces[j] * We assume dots go clockwise around the test face, * and faces go clockwise around dots. */ + + /* + * The end condition is slightly fiddly. In sufficiently strange + * degenerate grids, our test face may be adjacent to the same + * other face multiple times (typically if it's the exterior + * face). Consider this, in particular: + * + * +--+ + * | | + * +--+--+ + * | | | + * +--+--+ + * + * The bottom left face there is adjacent to the exterior face + * twice, so we can't just terminate our iteration when we reach + * the same _face_ we started at. Furthermore, we can't + * condition on having the same (i,j) pair either, because + * several (i,j) pairs identify the bottom left contiguity with + * the exterior face! We canonicalise the (i,j) pair by taking + * one step around before we set the termination tracking. + */ + i = j = 0; - starting_face = test_face->dots[0]->faces[0]; - if (starting_face == test_face) { + current_face = test_face->dots[0]->faces[0]; + if (current_face == test_face) { j = 1; - starting_face = test_face->dots[0]->faces[1]; + current_face = test_face->dots[0]->faces[1]; } - current_face = starting_face; transitions = 0; - current_state = FACE_LIT_STATE(current_face); - - do { + current_state = (FACE_COLOUR(current_face) == colour); + starting_dot = NULL; + starting_face = NULL; + while (TRUE) { /* Advance to next face. * Need to loop here because it might take several goes to * find it. */ @@ -1328,65 +1456,143 @@ static int can_light_face(grid *g, char* board, int face_index) } /* (i,j) are now advanced to next face */ current_face = test_face->dots[i]->faces[j]; - s = FACE_LIT_STATE(current_face); - if (s != current_state) { - ++transitions; - current_state = s; - if (transitions > 2) - return FALSE; /* no point in continuing */ + s = (FACE_COLOUR(current_face) == colour); + if (!starting_dot) { + starting_dot = test_face->dots[i]; + starting_face = current_face; + current_state = s; + } else { + if (s != current_state) { + ++transitions; + current_state = s; + if (transitions > 2) + break; + } + if (test_face->dots[i] == starting_dot && + current_face == starting_face) + break; } - } while (current_face != starting_face); + } return (transitions == 2) ? TRUE : FALSE; } -/* The 'score' of a face reflects its current desirability for selection - * as the next face to light. We want to encourage moving into uncharted - * areas so we give scores according to how many of the face's neighbours - * are currently unlit. */ -static int face_score(grid *g, char *board, grid_face *face) +/* Count the number of neighbours of 'face', having colour 'colour' */ +static int face_num_neighbours(grid *g, char *board, grid_face *face, + enum face_colour colour) { - /* Simple formula: score = neighbours unlit - neighbours lit */ - int lit_count = 0, unlit_count = 0; + int colour_count = 0; int i; grid_face *f; grid_edge *e; for (i = 0; i < face->order; i++) { e = face->edges[i]; f = (e->face1 == face) ? e->face2 : e->face1; - if (FACE_LIT_STATE(f) == FACE_LIT) - ++lit_count; - else - ++unlit_count; + if (FACE_COLOUR(f) == colour) + ++colour_count; } - return unlit_count - lit_count; + return colour_count; } -/* Generate a new complete set of clues for the given game_state. */ +/* The 'score' of a face reflects its current desirability for selection + * as the next face to colour white or black. We want to encourage moving + * into grey areas and increasing loopiness, so we give scores according to + * how many of the face's neighbours are currently coloured the same as the + * proposed colour. */ +static int face_score(grid *g, char *board, grid_face *face, + enum face_colour colour) +{ + /* Simple formula: score = 0 - num. same-coloured neighbours, + * so a higher score means fewer same-coloured neighbours. */ + return -face_num_neighbours(g, board, face, colour); +} + +/* Generate a new complete set of clues for the given game_state. + * The method is to generate a WHITE/BLACK colouring of all the faces, + * such that the WHITE faces will define the inside of the path, and the + * BLACK faces define the outside. + * To do this, we initially colour all faces GREY. The infinite space outside + * the grid is coloured BLACK, and we choose a random face to colour WHITE. + * Then we gradually grow the BLACK and the WHITE regions, eliminating GREY + * faces, until the grid is filled with BLACK/WHITE. As we grow the regions, + * we avoid creating loops of a single colour, to preserve the topological + * shape of the WHITE and BLACK regions. + * We also try to make the boundary as loopy and twisty as possible, to avoid + * generating paths that are uninteresting. + * The algorithm works by choosing a BLACK/WHITE colour, then choosing a GREY + * face that can be coloured with that colour (without violating the + * topological shape of that region). It's not obvious, but I think this + * algorithm is guaranteed to terminate without leaving any GREY faces behind. + * Indeed, if there are any GREY faces at all, both the WHITE and BLACK + * regions can be grown. + * This is checked using assert()ions, and I haven't seen any failures yet. + * + * Hand-wavy proof: imagine what can go wrong... + * + * Could the white faces get completely cut off by the black faces, and still + * leave some grey faces remaining? + * No, because then the black faces would form a loop around both the white + * faces and the grey faces, which is disallowed because we continually + * maintain the correct topological shape of the black region. + * Similarly, the black faces can never get cut off by the white faces. That + * means both the WHITE and BLACK regions always have some room to grow into + * the GREY regions. + * Could it be that we can't colour some GREY face, because there are too many + * WHITE/BLACK transitions as we walk round the face? (see the + * can_colour_face() function for details) + * No. Imagine otherwise, and we see WHITE/BLACK/WHITE/BLACK as we walk + * around the face. The two WHITE faces would be connected by a WHITE path, + * and the BLACK faces would be connected by a BLACK path. These paths would + * have to cross, which is impossible. + * Another thing that could go wrong: perhaps we can't find any GREY face to + * colour WHITE, because it would create a loop-violation or a corner-violation + * with the other WHITE faces? + * This is a little bit tricky to prove impossible. Imagine you have such a + * GREY face (that is, if you coloured it WHITE, you would create a WHITE loop + * or corner violation). + * That would cut all the non-white area into two blobs. One of those blobs + * must be free of BLACK faces (because the BLACK stuff is a connected blob). + * So we have a connected GREY area, completely surrounded by WHITE + * (including the GREY face we've tentatively coloured WHITE). + * A well-known result in graph theory says that you can always find a GREY + * face whose removal leaves the remaining GREY area connected. And it says + * there are at least two such faces, so we can always choose the one that + * isn't the "tentative" GREY face. Colouring that face WHITE leaves + * everything nice and connected, including that "tentative" GREY face which + * acts as a gateway to the rest of the non-WHITE grid. + */ static void add_full_clues(game_state *state, random_state *rs) { signed char *clues = state->clues; char *board; grid *g = state->game_grid; - int i, j, c; + int i, j; int num_faces = g->num_faces; - int first_time = TRUE; - - struct face *face, *tmpface; - struct face face_pos; - - /* These will contain exactly the same information, sorted into different - * orders */ - tree234 *lightable_faces_sorted, *lightable_faces_gettable; - -#define IS_LIGHTING_CANDIDATE(i) \ - (board[i] == FACE_UNLIT && \ - can_light_face(g, board, i)) + struct face_score *face_scores; /* Array of face_score objects */ + struct face_score *fs; /* Points somewhere in the above list */ + struct grid_face *cur_face; + tree234 *lightable_faces_sorted; + tree234 *darkable_faces_sorted; + int *face_list; + int do_random_pass; board = snewn(num_faces, char); /* Make a board */ - memset(board, FACE_UNLIT, num_faces); + memset(board, FACE_GREY, num_faces); + + /* Create and initialise the list of face_scores */ + face_scores = snewn(num_faces, struct face_score); + for (i = 0; i < num_faces; i++) { + face_scores[i].random = random_bits(rs, 31); + face_scores[i].black_score = face_scores[i].white_score = 0; + } + + /* Colour a random, finite face white. The infinite face is implicitly + * coloured black. Together, they will seed the random growth process + * for the black and white areas. */ + i = random_upto(rs, num_faces); + board[i] = FACE_WHITE; /* We need a way of favouring faces that will increase our loopiness. * We do this by maintaining a list of all candidate faces sorted by @@ -1400,123 +1606,187 @@ static void add_full_clues(game_state *state, random_state *rs) * Yes, this means we will be biased towards particular random faces in * any one run but that doesn't actually matter. */ - lightable_faces_sorted = newtree234(face_sort_cmpfn); - lightable_faces_gettable = newtree234(get_face_cmpfn); -#define ADD_FACE(f) \ - do { \ - struct face *x = add234(lightable_faces_sorted, f); \ - assert(x == f); \ - x = add234(lightable_faces_gettable, f); \ - assert(x == f); \ - } while (0) + lightable_faces_sorted = newtree234(white_sort_cmpfn); + darkable_faces_sorted = newtree234(black_sort_cmpfn); -#define REMOVE_FACE(f) \ - do { \ - struct face *x = del234(lightable_faces_sorted, f); \ - assert(x); \ - x = del234(lightable_faces_gettable, f); \ - assert(x); \ - } while (0) + /* Initialise the lists of lightable and darkable faces. This is + * slightly different from the code inside the while-loop, because we need + * to check every face of the board (the grid structure does not keep a + * list of the infinite face's neighbours). */ + for (i = 0; i < num_faces; i++) { + grid_face *f = g->faces + i; + struct face_score *fs = face_scores + i; + if (board[i] != FACE_GREY) continue; + /* We need the full colourability check here, it's not enough simply + * to check neighbourhood. On some grids, a neighbour of the infinite + * face is not necessarily darkable. */ + if (can_colour_face(g, board, i, FACE_BLACK)) { + fs->black_score = face_score(g, board, f, FACE_BLACK); + add234(darkable_faces_sorted, fs); + } + if (can_colour_face(g, board, i, FACE_WHITE)) { + fs->white_score = face_score(g, board, f, FACE_WHITE); + add234(lightable_faces_sorted, fs); + } + } - /* Light faces one at a time until the board is interesting enough */ + /* Colour faces one at a time until no more faces are colourable. */ while (TRUE) { - if (first_time) { - first_time = FALSE; - /* lightable_faces_xxx are empty, so start the process by - * lighting up the middle face. These tree234s should - * remain empty, consistent with what would happen if - * first_time were FALSE. */ - board[g->middle_face - g->faces] = FACE_LIT; - face = snew(struct face); - face->f = g->middle_face; - /* No need to initialise any more of 'face' here, no other fields - * are used in this case. */ - } else { - /* We have count234(lightable_faces_gettable) possibilities, and in - * lightable_faces_sorted they are sorted with the most desirable - * first. */ - c = count234(lightable_faces_sorted); - if (c == 0) - break; - assert(c == count234(lightable_faces_gettable)); - - /* Check that the best face available is any good */ - face = (struct face *)index234(lightable_faces_sorted, 0); - assert(face); - - /* - * The situation for a general grid is slightly different from - * a square grid. Decreasing the perimeter should be allowed - * sometimes (think about creating a hexagon of lit triangles, - * for example). For if it were _never_ done, then the user would - * be able to illicitly deduce certain things. So we do it - * sometimes but not always. - */ - if (face->score <= 0 && random_upto(rs, 2) == 0) { - break; - } + enum face_colour colour; + struct face_score *fs_white, *fs_black; + int c_lightable = count234(lightable_faces_sorted); + int c_darkable = count234(darkable_faces_sorted); + if (c_lightable == 0 && c_darkable == 0) { + /* No more faces we can use at all. */ + break; + } + assert(c_lightable != 0 && c_darkable != 0); - assert(face->f); /* not the infinite face */ - assert(FACE_LIT_STATE(face->f) == FACE_UNLIT); + fs_white = (struct face_score *)index234(lightable_faces_sorted, 0); + fs_black = (struct face_score *)index234(darkable_faces_sorted, 0); - /* Update data structures */ - /* Light up the face and remove it from the lists */ - board[face->f - g->faces] = FACE_LIT; - REMOVE_FACE(face); - } + /* Choose a colour, and colour the best available face + * with that colour. */ + colour = random_upto(rs, 2) ? FACE_WHITE : FACE_BLACK; - /* The face we've just lit up potentially affects the lightability - * of any neighbouring faces (touching at a corner or edge). So the - * search needs to be conducted around all faces touching the one - * we've just lit. Iterate over its corners, then over each corner's - * faces. */ - for (i = 0; i < face->f->order; i++) { - grid_dot *d = face->f->dots[i]; + if (colour == FACE_WHITE) + fs = fs_white; + else + fs = fs_black; + assert(fs); + i = fs - face_scores; + assert(board[i] == FACE_GREY); + board[i] = colour; + + /* Remove this newly-coloured face from the lists. These lists should + * only contain grey faces. */ + del234(lightable_faces_sorted, fs); + del234(darkable_faces_sorted, fs); + + /* Remember which face we've just coloured */ + cur_face = g->faces + i; + + /* The face we've just coloured potentially affects the colourability + * and the scores of any neighbouring faces (touching at a corner or + * edge). So the search needs to be conducted around all faces + * touching the one we've just lit. Iterate over its corners, then + * over each corner's faces. For each such face, we remove it from + * the lists, recalculate any scores, then add it back to the lists + * (depending on whether it is lightable, darkable or both). */ + for (i = 0; i < cur_face->order; i++) { + grid_dot *d = cur_face->dots[i]; for (j = 0; j < d->order; j++) { - grid_face *f2 = d->faces[j]; - if (f2 == NULL) + grid_face *f = d->faces[j]; + int fi; /* face index of f */ + + if (f == NULL) continue; - if (f2 == face->f) + if (f == cur_face) continue; - face_pos.f = f2; - tmpface = find234(lightable_faces_gettable, &face_pos, NULL); - if (tmpface) { - assert(tmpface->f == face_pos.f); - assert(FACE_LIT_STATE(tmpface->f) == FACE_UNLIT); - REMOVE_FACE(tmpface); - } else { - tmpface = snew(struct face); - tmpface->f = face_pos.f; - tmpface->random = random_bits(rs, 31); + + /* If the face is already coloured, it won't be on our + * lightable/darkable lists anyway, so we can skip it without + * bothering with the removal step. */ + if (FACE_COLOUR(f) != FACE_GREY) continue; + + /* Find the face index and face_score* corresponding to f */ + fi = f - g->faces; + fs = face_scores + fi; + + /* Remove from lightable list if it's in there. We do this, + * even if it is still lightable, because the score might + * be different, and we need to remove-then-add to maintain + * correct sort order. */ + del234(lightable_faces_sorted, fs); + if (can_colour_face(g, board, fi, FACE_WHITE)) { + fs->white_score = face_score(g, board, f, FACE_WHITE); + add234(lightable_faces_sorted, fs); } - tmpface->score = face_score(g, board, tmpface->f); - - if (IS_LIGHTING_CANDIDATE(tmpface->f - g->faces)) { - ADD_FACE(tmpface); - } else { - sfree(tmpface); + /* Do the same for darkable list. */ + del234(darkable_faces_sorted, fs); + if (can_colour_face(g, board, fi, FACE_BLACK)) { + fs->black_score = face_score(g, board, f, FACE_BLACK); + add234(darkable_faces_sorted, fs); } } } - sfree(face); } /* Clean up */ - while ((face = delpos234(lightable_faces_gettable, 0)) != NULL) - sfree(face); - freetree234(lightable_faces_gettable); freetree234(lightable_faces_sorted); + freetree234(darkable_faces_sorted); + sfree(face_scores); + + /* The next step requires a shuffled list of all faces */ + face_list = snewn(num_faces, int); + for (i = 0; i < num_faces; ++i) { + face_list[i] = i; + } + shuffle(face_list, num_faces, sizeof(int), rs); + + /* The above loop-generation algorithm can often leave large clumps + * of faces of one colour. In extreme cases, the resulting path can be + * degenerate and not very satisfying to solve. + * This next step alleviates this problem: + * Go through the shuffled list, and flip the colour of any face we can + * legally flip, and which is adjacent to only one face of the opposite + * colour - this tends to grow 'tendrils' into any clumps. + * Repeat until we can find no more faces to flip. This will + * eventually terminate, because each flip increases the loop's + * perimeter, which cannot increase for ever. + * The resulting path will have maximal loopiness (in the sense that it + * cannot be improved "locally". Unfortunately, this allows a player to + * make some illicit deductions. To combat this (and make the path more + * interesting), we do one final pass making random flips. */ + + /* Set to TRUE for final pass */ + do_random_pass = FALSE; + + while (TRUE) { + /* Remember whether a flip occurred during this pass */ + int flipped = FALSE; + + for (i = 0; i < num_faces; ++i) { + int j = face_list[i]; + enum face_colour opp = + (board[j] == FACE_WHITE) ? FACE_BLACK : FACE_WHITE; + if (can_colour_face(g, board, j, opp)) { + grid_face *face = g->faces +j; + if (do_random_pass) { + /* final random pass */ + if (!random_upto(rs, 10)) + board[j] = opp; + } else { + /* normal pass - flip when neighbour count is 1 */ + if (face_num_neighbours(g, board, face, opp) == 1) { + board[j] = opp; + flipped = TRUE; + } + } + } + } + + if (do_random_pass) break; + if (!flipped) do_random_pass = TRUE; + } + + sfree(face_list); /* Fill out all the clues by initialising to 0, then iterating over * all edges and incrementing each clue as we find edges that border - * between LIT/UNLIT faces */ + * between BLACK/WHITE faces. While we're at it, we verify that the + * algorithm does work, and there aren't any GREY faces still there. */ memset(clues, 0, num_faces); for (i = 0; i < g->num_edges; i++) { grid_edge *e = g->edges + i; grid_face *f1 = e->face1; grid_face *f2 = e->face2; - if (FACE_LIT_STATE(f1) != FACE_LIT_STATE(f2)) { + enum face_colour c1 = FACE_COLOUR(f1); + enum face_colour c2 = FACE_COLOUR(f2); + assert(c1 != FACE_GREY); + assert(c2 != FACE_GREY); + if (c1 != c2) { if (f1) clues[f1 - g->faces]++; if (f2) clues[f2 - g->faces]++; } @@ -1532,7 +1802,7 @@ static int game_has_unique_soln(const game_state *state, int diff) solver_state *sstate_new; solver_state *sstate = new_solver_state((game_state *)state, diff); - sstate_new = solve_game_rec(sstate, diff); + sstate_new = solve_game_rec(sstate); assert(sstate_new->solver_status != SOLVER_MISTAKE); ret = (sstate_new->solver_status == SOLVER_SOLVED); @@ -1585,21 +1855,24 @@ static char *new_game_desc(game_params *params, random_state *rs, char **aux, int interactive) { /* solution and description both use run-length encoding in obvious ways */ - char *retval; + char *retval, *game_desc, *grid_desc; grid *g; game_state *state = snew(game_state); game_state *state_new; - params_generate_grid(params); - state->game_grid = g = params->game_grid; - g->refcount++; + + grid_desc = grid_new_desc(grid_types[params->type], params->w, params->h, rs); + state->game_grid = g = loopy_generate_grid(params, grid_desc); + state->clues = snewn(g->num_faces, signed char); state->lines = snewn(g->num_edges, char); + state->line_errors = snewn(g->num_edges, unsigned char); state->grid_type = params->type; newboard_please: memset(state->lines, LINE_UNKNOWN, g->num_edges); + memset(state->line_errors, 0, g->num_edges); state->solved = state->cheated = FALSE; @@ -1622,10 +1895,19 @@ static char *new_game_desc(game_params *params, random_state *rs, goto newboard_please; } - retval = state_to_text(state); + game_desc = state_to_text(state); free_game(state); + if (grid_desc) { + retval = snewn(strlen(grid_desc) + 1 + strlen(game_desc) + 1, char); + sprintf(retval, "%s%c%s", grid_desc, (int)GRID_DESC_SEP, game_desc); + sfree(grid_desc); + sfree(game_desc); + } else { + retval = game_desc; + } + assert(!validate_desc(params, retval)); return retval; @@ -1636,19 +1918,24 @@ static game_state *new_game(midend *me, game_params *params, char *desc) int i; game_state *state = snew(game_state); int empties_to_make = 0; - int n; - const char *dp = desc; + int n,n2; + const char *dp; + char *grid_desc; grid *g; int num_faces, num_edges; - params_generate_grid(params); - state->game_grid = g = params->game_grid; - g->refcount++; + grid_desc = extract_grid_desc(&desc); + state->game_grid = g = loopy_generate_grid(params, grid_desc); + if (grid_desc) sfree(grid_desc); + + dp = desc; + num_faces = g->num_faces; num_edges = g->num_edges; state->clues = snewn(num_faces, signed char); state->lines = snewn(num_edges, char); + state->line_errors = snewn(num_edges, unsigned char); state->solved = state->cheated = FALSE; @@ -1663,8 +1950,11 @@ static game_state *new_game(midend *me, game_params *params, char *desc) assert(*dp); n = *dp - '0'; + n2 = *dp - 'A' + 10; if (n >= 0 && n < 10) { state->clues[i] = n; + } else if (n2 >= 10 && n2 < 36) { + state->clues[i] = n2; } else { n = *dp - 'a' + 1; assert(n > 0); @@ -1675,11 +1965,165 @@ static game_state *new_game(midend *me, game_params *params, char *desc) } memset(state->lines, LINE_UNKNOWN, num_edges); - + memset(state->line_errors, 0, num_edges); return state; } -enum { LOOP_NONE=0, LOOP_SOLN, LOOP_NOT_SOLN }; +/* Calculates the line_errors data, and checks if the current state is a + * solution */ +static int check_completion(game_state *state) +{ + grid *g = state->game_grid; + int *dsf; + int num_faces = g->num_faces; + int i; + int infinite_area, finite_area; + int loops_found = 0; + int found_edge_not_in_loop = FALSE; + + memset(state->line_errors, 0, g->num_edges); + + /* LL implementation of SGT's idea: + * A loop will partition the grid into an inside and an outside. + * If there is more than one loop, the grid will be partitioned into + * even more distinct regions. We can therefore track equivalence of + * faces, by saying that two faces are equivalent when there is a non-YES + * edge between them. + * We could keep track of the number of connected components, by counting + * the number of dsf-merges that aren't no-ops. + * But we're only interested in 3 separate cases: + * no loops, one loop, more than one loop. + * + * No loops: all faces are equivalent to the infinite face. + * One loop: only two equivalence classes - finite and infinite. + * >= 2 loops: there are 2 distinct finite regions. + * + * So we simply make two passes through all the edges. + * In the first pass, we dsf-merge the two faces bordering each non-YES + * edge. + * In the second pass, we look for YES-edges bordering: + * a) two non-equivalent faces. + * b) two non-equivalent faces, and one of them is part of a different + * finite area from the first finite area we've seen. + * + * An occurrence of a) means there is at least one loop. + * An occurrence of b) means there is more than one loop. + * Edges satisfying a) are marked as errors. + * + * While we're at it, we set a flag if we find a YES edge that is not + * part of a loop. + * This information will help decide, if there's a single loop, whether it + * is a candidate for being a solution (that is, all YES edges are part of + * this loop). + * + * If there is a candidate loop, we then go through all clues and check + * they are all satisfied. If so, we have found a solution and we can + * unmark all line_errors. + */ + + /* Infinite face is at the end - its index is num_faces. + * This macro is just to make this obvious! */ + #define INF_FACE num_faces + dsf = snewn(num_faces + 1, int); + dsf_init(dsf, num_faces + 1); + + /* First pass */ + for (i = 0; i < g->num_edges; i++) { + grid_edge *e = g->edges + i; + int f1 = e->face1 ? e->face1 - g->faces : INF_FACE; + int f2 = e->face2 ? e->face2 - g->faces : INF_FACE; + if (state->lines[i] != LINE_YES) + dsf_merge(dsf, f1, f2); + } + + /* Second pass */ + infinite_area = dsf_canonify(dsf, INF_FACE); + finite_area = -1; + for (i = 0; i < g->num_edges; i++) { + grid_edge *e = g->edges + i; + int f1 = e->face1 ? e->face1 - g->faces : INF_FACE; + int can1 = dsf_canonify(dsf, f1); + int f2 = e->face2 ? e->face2 - g->faces : INF_FACE; + int can2 = dsf_canonify(dsf, f2); + if (state->lines[i] != LINE_YES) continue; + + if (can1 == can2) { + /* Faces are equivalent, so this edge not part of a loop */ + found_edge_not_in_loop = TRUE; + continue; + } + state->line_errors[i] = TRUE; + if (loops_found == 0) loops_found = 1; + + /* Don't bother with further checks if we've already found 2 loops */ + if (loops_found == 2) continue; + + if (finite_area == -1) { + /* Found our first finite area */ + if (can1 != infinite_area) + finite_area = can1; + else + finite_area = can2; + } + + /* Have we found a second area? */ + if (finite_area != -1) { + if (can1 != infinite_area && can1 != finite_area) { + loops_found = 2; + continue; + } + if (can2 != infinite_area && can2 != finite_area) { + loops_found = 2; + } + } + } + +/* + printf("loops_found = %d\n", loops_found); + printf("found_edge_not_in_loop = %s\n", + found_edge_not_in_loop ? "TRUE" : "FALSE"); +*/ + + sfree(dsf); /* No longer need the dsf */ + + /* Have we found a candidate loop? */ + if (loops_found == 1 && !found_edge_not_in_loop) { + /* Yes, so check all clues are satisfied */ + int found_clue_violation = FALSE; + for (i = 0; i < num_faces; i++) { + int c = state->clues[i]; + if (c >= 0) { + if (face_order(state, i, LINE_YES) != c) { + found_clue_violation = TRUE; + break; + } + } + } + + if (!found_clue_violation) { + /* The loop is good */ + memset(state->line_errors, 0, g->num_edges); + return TRUE; /* No need to bother checking for dot violations */ + } + } + + /* Check for dot violations */ + for (i = 0; i < g->num_dots; i++) { + int yes = dot_order(state, i, LINE_YES); + int unknown = dot_order(state, i, LINE_UNKNOWN); + if ((yes == 1 && unknown == 0) || (yes >= 3)) { + /* violation, so mark all YES edges as errors */ + grid_dot *d = g->dots + i; + int j; + for (j = 0; j < d->order; j++) { + int e = d->edges[j] - g->edges; + if (state->lines[e] == LINE_YES) + state->line_errors[e] = TRUE; + } + } + } + return FALSE; +} /* ---------------------------------------------------------------------- * Solver logic @@ -1689,7 +2133,7 @@ enum { LOOP_NONE=0, LOOP_SOLN, LOOP_NOT_SOLN }; * Easy Mode * Just implement the rules of the game. * - * Normal Mode + * Normal and Tricky Modes * For each (adjacent) pair of lines through each dot we store a bit for * whether at least one of them is on and whether at most one is on. (If we * know both or neither is on that's already stored more directly.) @@ -1826,7 +2270,7 @@ static int dline_set_opp_atleastone(solver_state *sstate, continue; /* Found opposite UNKNOWNS and they're next to each other */ opp_dline_index = dline_index_from_dot(g, d, opp); - return set_atleastone(sstate->normal->dlines, opp_dline_index); + return set_atleastone(sstate->dlines, opp_dline_index); } return FALSE; } @@ -1859,8 +2303,8 @@ static int face_setall_identical(solver_state *sstate, int face_index, continue; /* Found two UNKNOWNS */ - can1 = edsf_canonify(sstate->hard->linedsf, line1_index, &inv1); - can2 = edsf_canonify(sstate->hard->linedsf, line2_index, &inv2); + can1 = edsf_canonify(sstate->linedsf, line1_index, &inv1); + can2 = edsf_canonify(sstate->linedsf, line2_index, &inv2); if (can1 == can2 && inv1 == inv2) { solver_set_line(sstate, line1_index, line_new); solver_set_line(sstate, line2_index, line_new); @@ -1901,7 +2345,7 @@ static int parity_deductions(solver_state *sstate, { game_state *state = sstate->state; int diff = DIFF_MAX; - int *linedsf = sstate->hard->linedsf; + int *linedsf = sstate->linedsf; if (unknown_count == 2) { /* Lines are known alike/opposite, depending on inv. */ @@ -2000,7 +2444,7 @@ static int parity_deductions(solver_state *sstate, * Answer: first all squares then all dots. */ -static int easy_mode_deductions(solver_state *sstate) +static int trivial_deductions(solver_state *sstate) { int i, current_yes, current_no; game_state *state = sstate->state; @@ -2025,6 +2469,13 @@ static int easy_mode_deductions(solver_state *sstate) if (state->clues[i] < 0) continue; + /* + * This code checks whether the numeric clue on a face is so + * large as to permit all its remaining LINE_UNKNOWNs to be + * filled in as LINE_YES, or alternatively so small as to + * permit them all to be filled in as LINE_NO. + */ + if (state->clues[i] < current_yes) { sstate->solver_status = SOLVER_MISTAKE; return DIFF_EASY; @@ -2046,6 +2497,57 @@ static int easy_mode_deductions(solver_state *sstate) sstate->face_solved[i] = TRUE; continue; } + + if (f->order - state->clues[i] == current_no + 1 && + f->order - current_yes - current_no > 2) { + /* + * One small refinement to the above: we also look for any + * adjacent pair of LINE_UNKNOWNs around the face with + * some LINE_YES incident on it from elsewhere. If we find + * one, then we know that pair of LINE_UNKNOWNs can't + * _both_ be LINE_YES, and hence that pushes us one line + * closer to being able to determine all the rest. + */ + int j, k, e1, e2, e, d; + + for (j = 0; j < f->order; j++) { + e1 = f->edges[j] - g->edges; + e2 = f->edges[j+1 < f->order ? j+1 : 0] - g->edges; + + if (g->edges[e1].dot1 == g->edges[e2].dot1 || + g->edges[e1].dot1 == g->edges[e2].dot2) { + d = g->edges[e1].dot1 - g->dots; + } else { + assert(g->edges[e1].dot2 == g->edges[e2].dot1 || + g->edges[e1].dot2 == g->edges[e2].dot2); + d = g->edges[e1].dot2 - g->dots; + } + + if (state->lines[e1] == LINE_UNKNOWN && + state->lines[e2] == LINE_UNKNOWN) { + for (k = 0; k < g->dots[d].order; k++) { + int e = g->dots[d].edges[k] - g->edges; + if (state->lines[e] == LINE_YES) + goto found; /* multi-level break */ + } + } + } + continue; + + found: + /* + * If we get here, we've found such a pair of edges, and + * they're e1 and e2. + */ + for (j = 0; j < f->order; j++) { + e = f->edges[j] - g->edges; + if (state->lines[e] == LINE_UNKNOWN && e != e1 && e != e2) { + int r = solver_set_line(sstate, e, LINE_YES); + assert(r); + diff = min(diff, DIFF_EASY); + } + } + } } check_caches(sstate); @@ -2095,11 +2597,11 @@ static int easy_mode_deductions(solver_state *sstate) return diff; } -static int normal_mode_deductions(solver_state *sstate) +static int dline_deductions(solver_state *sstate) { game_state *state = sstate->state; grid *g = state->game_grid; - char *dlines = sstate->normal->dlines; + char *dlines = sstate->dlines; int i; int diff = DIFF_MAX; @@ -2144,7 +2646,7 @@ static int normal_mode_deductions(solver_state *sstate) * on that. We check this with an assertion, in case someone decides to * make a grid which has larger faces than this. Note, this algorithm * could get quite expensive if there are many large faces. */ -#define MAX_FACE_SIZE 8 +#define MAX_FACE_SIZE 12 for (i = 0; i < g->num_faces; i++) { int maxs[MAX_FACE_SIZE][MAX_FACE_SIZE]; @@ -2245,29 +2747,34 @@ static int normal_mode_deductions(solver_state *sstate) diff = min(diff, DIFF_EASY); } - /* Now see if we can make dline deduction for edges{j,j+1} */ - e = f->edges[k]; - if (state->lines[e - g->edges] != LINE_UNKNOWN) - /* Only worth doing this for an UNKNOWN,UNKNOWN pair. - * Dlines where one of the edges is known, are handled in the - * dot-deductions */ - continue; - - dline_index = dline_index_from_face(g, f, k); - k++; - if (k >= N) k = 0; - - /* minimum YESs in the complement of this dline */ - if (mins[k][j] > clue - 2) { - /* Adding 2 YESs would break the clue */ - if (set_atmostone(dlines, dline_index)) - diff = min(diff, DIFF_NORMAL); - } - /* maximum YESs in the complement of this dline */ - if (maxs[k][j] < clue) { - /* Adding 2 NOs would mean not enough YESs */ - if (set_atleastone(dlines, dline_index)) - diff = min(diff, DIFF_NORMAL); + /* More advanced deduction that allows propagation along diagonal + * chains of faces connected by dots, for example, 3-2-...-2-3 + * in square grids. */ + if (sstate->diff >= DIFF_TRICKY) { + /* Now see if we can make dline deduction for edges{j,j+1} */ + e = f->edges[k]; + if (state->lines[e - g->edges] != LINE_UNKNOWN) + /* Only worth doing this for an UNKNOWN,UNKNOWN pair. + * Dlines where one of the edges is known, are handled in the + * dot-deductions */ + continue; + + dline_index = dline_index_from_face(g, f, k); + k++; + if (k >= N) k = 0; + + /* minimum YESs in the complement of this dline */ + if (mins[k][j] > clue - 2) { + /* Adding 2 YESs would break the clue */ + if (set_atmostone(dlines, dline_index)) + diff = min(diff, DIFF_NORMAL); + } + /* maximum YESs in the complement of this dline */ + if (maxs[k][j] < clue) { + /* Adding 2 NOs would mean not enough YESs */ + if (set_atleastone(dlines, dline_index)) + diff = min(diff, DIFF_NORMAL); + } } } } @@ -2361,48 +2868,54 @@ static int normal_mode_deductions(solver_state *sstate) } } - /* If we have atleastone set for this dline, infer - * atmostone for each "opposite" dline (that is, each - * dline without edges in common with this one). - * Again, this test is only worth doing if both these - * lines are UNKNOWN. For if one of these lines were YES, - * the (yes == 1) test above would kick in instead. */ - if (is_atleastone(dlines, dline_index)) { - int opp; - for (opp = 0; opp < N; opp++) { - int opp_dline_index; - if (opp == j || opp == j+1 || opp == j-1) - continue; - if (j == 0 && opp == N-1) - continue; - if (j == N-1 && opp == 0) - continue; - opp_dline_index = dline_index_from_dot(g, d, opp); - if (set_atmostone(dlines, opp_dline_index)) - diff = min(diff, DIFF_NORMAL); - } - - if (yes == 0 && is_atmostone(dlines, dline_index)) { - /* This dline has *exactly* one YES and there are no - * other YESs. This allows more deductions. */ - if (unknown == 3) { - /* Third unknown must be YES */ - for (opp = 0; opp < N; opp++) { - int opp_index; - if (opp == j || opp == k) - continue; - opp_index = d->edges[opp] - g->edges; - if (state->lines[opp_index] == LINE_UNKNOWN) { - solver_set_line(sstate, opp_index, LINE_YES); - diff = min(diff, DIFF_EASY); + /* More advanced deduction that allows propagation along diagonal + * chains of faces connected by dots, for example: 3-2-...-2-3 + * in square grids. */ + if (sstate->diff >= DIFF_TRICKY) { + /* If we have atleastone set for this dline, infer + * atmostone for each "opposite" dline (that is, each + * dline without edges in common with this one). + * Again, this test is only worth doing if both these + * lines are UNKNOWN. For if one of these lines were YES, + * the (yes == 1) test above would kick in instead. */ + if (is_atleastone(dlines, dline_index)) { + int opp; + for (opp = 0; opp < N; opp++) { + int opp_dline_index; + if (opp == j || opp == j+1 || opp == j-1) + continue; + if (j == 0 && opp == N-1) + continue; + if (j == N-1 && opp == 0) + continue; + opp_dline_index = dline_index_from_dot(g, d, opp); + if (set_atmostone(dlines, opp_dline_index)) + diff = min(diff, DIFF_NORMAL); + } + if (yes == 0 && is_atmostone(dlines, dline_index)) { + /* This dline has *exactly* one YES and there are no + * other YESs. This allows more deductions. */ + if (unknown == 3) { + /* Third unknown must be YES */ + for (opp = 0; opp < N; opp++) { + int opp_index; + if (opp == j || opp == k) + continue; + opp_index = d->edges[opp] - g->edges; + if (state->lines[opp_index] == LINE_UNKNOWN) { + solver_set_line(sstate, opp_index, + LINE_YES); + diff = min(diff, DIFF_EASY); + } } + } else if (unknown == 4) { + /* Exactly one of opposite UNKNOWNS is YES. We've + * already set atmostone, so set atleastone as + * well. + */ + if (dline_set_opp_atleastone(sstate, d, j)) + diff = min(diff, DIFF_NORMAL); } - } else if (unknown == 4) { - /* Exactly one of opposite UNKNOWNS is YES. We've - * already set atmostone, so set atleastone as well. - */ - if (dline_set_opp_atleastone(sstate, d, j)) - diff = min(diff, DIFF_NORMAL); } } } @@ -2411,11 +2924,11 @@ static int normal_mode_deductions(solver_state *sstate) return diff; } -static int hard_mode_deductions(solver_state *sstate) +static int linedsf_deductions(solver_state *sstate) { game_state *state = sstate->state; grid *g = state->game_grid; - char *dlines = sstate->normal->dlines; + char *dlines = sstate->dlines; int i; int diff = DIFF_MAX; int diff_tmp; @@ -2485,8 +2998,8 @@ static int hard_mode_deductions(solver_state *sstate) if (state->lines[line2_index] != LINE_UNKNOWN) continue; /* Infer dline flags from linedsf */ - can1 = edsf_canonify(sstate->hard->linedsf, line1_index, &inv1); - can2 = edsf_canonify(sstate->hard->linedsf, line2_index, &inv2); + can1 = edsf_canonify(sstate->linedsf, line1_index, &inv1); + can2 = edsf_canonify(sstate->linedsf, line2_index, &inv2); if (can1 == can2 && inv1 != inv2) { /* These are opposites, so set dline atmostone/atleastone */ if (set_atmostone(dlines, dline_index)) @@ -2520,7 +3033,7 @@ static int hard_mode_deductions(solver_state *sstate) for (i = 0; i < g->num_edges; i++) { int can, inv; enum line_state s; - can = edsf_canonify(sstate->hard->linedsf, i, &inv); + can = edsf_canonify(sstate->linedsf, i, &inv); if (can == i) continue; s = sstate->state->lines[can]; @@ -2693,52 +3206,59 @@ static int loop_deductions(solver_state *sstate) /* This will return a dynamically allocated solver_state containing the (more) * solved grid */ -static solver_state *solve_game_rec(const solver_state *sstate_start, - int diff) -{ - solver_state *sstate, *sstate_saved; - int solver_progress; - game_state *state; - - /* Indicates which solver we should call next. This is a sensible starting - * point */ - int current_solver = DIFF_EASY, next_solver; +static solver_state *solve_game_rec(const solver_state *sstate_start) +{ + solver_state *sstate; + + /* Index of the solver we should call next. */ + int i = 0; + + /* As a speed-optimisation, we avoid re-running solvers that we know + * won't make any progress. This happens when a high-difficulty + * solver makes a deduction that can only help other high-difficulty + * solvers. + * For example: if a new 'dline' flag is set by dline_deductions, the + * trivial_deductions solver cannot do anything with this information. + * If we've already run the trivial_deductions solver (because it's + * earlier in the list), there's no point running it again. + * + * Therefore: if a solver is earlier in the list than "threshold_index", + * we don't bother running it if it's difficulty level is less than + * "threshold_diff". + */ + int threshold_diff = 0; + int threshold_index = 0; + sstate = dup_solver_state(sstate_start); - /* Cache the values of some variables for readability */ - state = sstate->state; - - sstate_saved = NULL; - - solver_progress = FALSE; - check_caches(sstate); - do { + while (i < NUM_SOLVERS) { if (sstate->solver_status == SOLVER_MISTAKE) return sstate; - - next_solver = solver_fns[current_solver](sstate); - - if (next_solver == DIFF_MAX) { - if (current_solver < diff && current_solver + 1 < DIFF_MAX) { - /* Try next beefier solver */ - next_solver = current_solver + 1; - } else { - next_solver = loop_deductions(sstate); - } - } - if (sstate->solver_status == SOLVER_SOLVED || sstate->solver_status == SOLVER_AMBIGUOUS) { -/* fprintf(stderr, "Solver completed\n"); */ + /* solver finished */ break; } - /* Once we've looped over all permitted solvers then the loop - * deductions without making any progress, we'll exit this while loop */ - current_solver = next_solver; - } while (current_solver < DIFF_MAX); + if ((solver_diffs[i] >= threshold_diff || i >= threshold_index) + && solver_diffs[i] <= sstate->diff) { + /* current_solver is eligible, so use it */ + int next_diff = solver_fns[i](sstate); + if (next_diff != DIFF_MAX) { + /* solver made progress, so use new thresholds and + * start again at top of list. */ + threshold_diff = next_diff; + threshold_index = i; + i = 0; + continue; + } + } + /* current_solver is ineligible, or failed to make progress, so + * go to the next solver in the list */ + i++; + } if (sstate->solver_status == SOLVER_SOLVED || sstate->solver_status == SOLVER_AMBIGUOUS) { @@ -2758,7 +3278,7 @@ static char *solve_game(game_state *state, game_state *currstate, solver_state *sstate, *new_sstate; sstate = new_solver_state(state, DIFF_MAX); - new_sstate = solve_game_rec(sstate, DIFF_MAX); + new_sstate = solve_game_rec(sstate); if (new_sstate->solver_status == SOLVER_SOLVED) { soln = encode_solve_move(new_sstate->state); @@ -2817,6 +3337,10 @@ static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds, button_char = 'y'; break; case LINE_YES: +#ifdef STYLUS_BASED + button_char = 'n'; + break; +#endif case LINE_NO: button_char = 'u'; break; @@ -2831,6 +3355,10 @@ static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds, button_char = 'n'; break; case LINE_NO: +#ifdef STYLUS_BASED + button_char = 'y'; + break; +#endif case LINE_YES: button_char = 'u'; break; @@ -2851,7 +3379,6 @@ static game_state *execute_move(game_state *state, char *move) { int i; game_state *newstate = dup_game(state); - grid *g = state->game_grid; if (move[0] == 'S') { move++; @@ -2860,6 +3387,8 @@ static game_state *execute_move(game_state *state, char *move) while (*move) { i = atoi(move); + if (i < 0 || i >= newstate->game_grid->num_edges) + goto fail; move += strspn(move, "1234567890"); switch (*(move++)) { case 'y': @@ -2879,77 +3408,9 @@ static game_state *execute_move(game_state *state, char *move) /* * Check for completion. */ - for (i = 0; i < g->num_edges; i++) { - if (newstate->lines[i] == LINE_YES) - break; - } - if (i < g->num_edges) { - int looplen, count; - grid_edge *start_edge = g->edges + i; - grid_edge *e = start_edge; - grid_dot *d = e->dot1; - /* - * We've found an edge i. Follow it round - * to see if it's part of a loop. - */ - looplen = 0; - while (1) { - int j; - int order = dot_order(newstate, d - g->dots, LINE_YES); - if (order != 2) - goto completion_check_done; - - /* Find other edge around this dot */ - for (j = 0; j < d->order; j++) { - grid_edge *e2 = d->edges[j]; - if (e2 != e && newstate->lines[e2 - g->edges] == LINE_YES) - break; - } - assert(j != d->order); /* dot_order guarantees success */ - - e = d->edges[j]; - d = (e->dot1 == d) ? e->dot2 : e->dot1; - looplen++; - - if (e == start_edge) - break; - } - - /* - * We've traced our way round a loop, and we know how many - * line segments were involved. Count _all_ the line - * segments in the grid, to see if the loop includes them - * all. - */ - count = 0; - for (i = 0; i < g->num_edges; i++) { - if (newstate->lines[i] == LINE_YES) - count++; - } - assert(count >= looplen); - if (count != looplen) - goto completion_check_done; - - /* - * The grid contains one closed loop and nothing else. - * Check that all the clues are satisfied. - */ - for (i = 0; i < g->num_faces; i++) { - int c = newstate->clues[i]; - if (c >= 0) { - if (face_order(newstate, i, LINE_YES) != c) { - goto completion_check_done; - } - } - } - - /* - * Completed! - */ + if (check_completion(newstate)) newstate->solved = TRUE; - } - completion_check_done: return newstate; fail: @@ -2976,241 +3437,335 @@ static void grid_to_screen(const game_drawstate *ds, const grid *g, /* Returns (into x,y) position of centre of face for rendering the text clue. */ static void face_text_pos(const game_drawstate *ds, const grid *g, - const grid_face *f, int *x, int *y) + grid_face *f, int *xret, int *yret) { - int i; + int faceindex = f - g->faces; - /* Simplest solution is the centroid. Might not work in some cases. */ + /* + * Return the cached position for this face, if we've already + * worked it out. + */ + if (ds->textx[faceindex] >= 0) { + *xret = ds->textx[faceindex]; + *yret = ds->texty[faceindex]; + return; + } - /* Another algorithm to look into: - * Find the midpoints of the sides, find the bounding-box, - * then take the centre of that. */ + /* + * Otherwise, use the incentre computed by grid.c and convert it + * to screen coordinates. + */ + grid_find_incentre(f); + grid_to_screen(ds, g, f->ix, f->iy, + &ds->textx[faceindex], &ds->texty[faceindex]); - /* Best solution probably involves incentres (inscribed circles) */ + *xret = ds->textx[faceindex]; + *yret = ds->texty[faceindex]; +} - int sx = 0, sy = 0; /* sums */ - for (i = 0; i < f->order; i++) { - grid_dot *d = f->dots[i]; - sx += d->x; - sy += d->y; - } - sx /= f->order; - sy /= f->order; +static void face_text_bbox(game_drawstate *ds, grid *g, grid_face *f, + int *x, int *y, int *w, int *h) +{ + int xx, yy; + face_text_pos(ds, g, f, &xx, &yy); + + /* There seems to be a certain amount of trial-and-error involved + * in working out the correct bounding-box for the text. */ - /* convert to screen coordinates */ - grid_to_screen(ds, g, sx, sy, x, y); + *x = xx - ds->tilesize/4 - 1; + *y = yy - ds->tilesize/4 - 3; + *w = ds->tilesize/2 + 2; + *h = ds->tilesize/2 + 5; } -static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate, - game_state *state, int dir, game_ui *ui, - float animtime, float flashtime) +static void game_redraw_clue(drawing *dr, game_drawstate *ds, + game_state *state, int i) { grid *g = state->game_grid; - int border = BORDER(ds->tilesize); - int i, n; - char c[2]; - int line_colour, flash_changed; - int clue_mistake; - int clue_satisfied; + grid_face *f = g->faces + i; + int x, y; + char c[3]; - 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. - */ - int grid_width = g->highest_x - g->lowest_x; - int grid_height = g->highest_y - g->lowest_y; - int w = grid_width * ds->tilesize / g->tilesize; - int h = grid_height * ds->tilesize / g->tilesize; - draw_rect(dr, 0, 0, w + 2 * border, h + 2 * border, COL_BACKGROUND); + if (state->clues[i] < 10) { + c[0] = CLUE2CHAR(state->clues[i]); + c[1] = '\0'; + } else { + sprintf(c, "%d", state->clues[i]); + } - /* Draw clues */ - for (i = 0; i < g->num_faces; i++) { - grid_face *f; - int x, y; + face_text_pos(ds, g, f, &x, &y); + draw_text(dr, x, y, + FONT_VARIABLE, ds->tilesize/2, + ALIGN_VCENTRE | ALIGN_HCENTRE, + ds->clue_error[i] ? COL_MISTAKE : + ds->clue_satisfied[i] ? COL_SATISFIED : COL_FOREGROUND, c); +} - c[0] = CLUE2CHAR(state->clues[i]); - c[1] = '\0'; - f = g->faces + i; - face_text_pos(ds, g, f, &x, &y); - draw_text(dr, x, y, FONT_VARIABLE, ds->tilesize/2, - ALIGN_VCENTRE | ALIGN_HCENTRE, COL_FOREGROUND, c); - } - draw_update(dr, 0, 0, w + 2 * border, h + 2 * border); - } +static void edge_bbox(game_drawstate *ds, grid *g, grid_edge *e, + int *x, int *y, int *w, int *h) +{ + int x1 = e->dot1->x; + int y1 = e->dot1->y; + int x2 = e->dot2->x; + int y2 = e->dot2->y; + int xmin, xmax, ymin, ymax; + + grid_to_screen(ds, g, x1, y1, &x1, &y1); + grid_to_screen(ds, g, x2, y2, &x2, &y2); + /* Allow extra margin for dots, and thickness of lines */ + xmin = min(x1, x2) - 2; + xmax = max(x1, x2) + 2; + ymin = min(y1, y2) - 2; + ymax = max(y1, y2) + 2; + + *x = xmin; + *y = ymin; + *w = xmax - xmin + 1; + *h = ymax - ymin + 1; +} + +static void dot_bbox(game_drawstate *ds, grid *g, grid_dot *d, + int *x, int *y, int *w, int *h) +{ + int x1, y1; + + grid_to_screen(ds, g, d->x, d->y, &x1, &y1); + + *x = x1 - 2; + *y = y1 - 2; + *w = 5; + *h = 5; +} - if (flashtime > 0 && - (flashtime <= FLASH_TIME/3 || - flashtime >= FLASH_TIME*2/3)) { - flash_changed = !ds->flashing; - ds->flashing = TRUE; +static const int loopy_line_redraw_phases[] = { + COL_FAINT, COL_LINEUNKNOWN, COL_FOREGROUND, COL_HIGHLIGHT, COL_MISTAKE +}; +#define NPHASES lenof(loopy_line_redraw_phases) + +static void game_redraw_line(drawing *dr, game_drawstate *ds, + game_state *state, int i, int phase) +{ + grid *g = state->game_grid; + grid_edge *e = g->edges + i; + int x1, x2, y1, y2; + int line_colour; + + if (state->line_errors[i]) + line_colour = COL_MISTAKE; + else if (state->lines[i] == LINE_UNKNOWN) + line_colour = COL_LINEUNKNOWN; + else if (state->lines[i] == LINE_NO) + line_colour = COL_FAINT; + else if (ds->flashing) + line_colour = COL_HIGHLIGHT; + else + line_colour = COL_FOREGROUND; + if (line_colour != loopy_line_redraw_phases[phase]) + return; + + /* Convert from grid to screen coordinates */ + grid_to_screen(ds, g, e->dot1->x, e->dot1->y, &x1, &y1); + grid_to_screen(ds, g, e->dot2->x, e->dot2->y, &x2, &y2); + + if (line_colour == COL_FAINT) { + static int draw_faint_lines = -1; + if (draw_faint_lines < 0) { + char *env = getenv("LOOPY_FAINT_LINES"); + draw_faint_lines = (!env || (env[0] == 'y' || + env[0] == 'Y')); + } + if (draw_faint_lines) + draw_line(dr, x1, y1, x2, y2, line_colour); } else { - flash_changed = ds->flashing; - ds->flashing = FALSE; + draw_thick_line(dr, 3.0, + x1 + 0.5, y1 + 0.5, + x2 + 0.5, y2 + 0.5, + line_colour); } +} + +static void game_redraw_dot(drawing *dr, game_drawstate *ds, + game_state *state, int i) +{ + grid *g = state->game_grid; + grid_dot *d = g->dots + i; + int x, y; - /* Some platforms may perform anti-aliasing, which may prevent clean - * repainting of lines when the colour is changed. - * If a line needs to be over-drawn in a different colour, erase a - * bounding-box around the line, then flag all nearby objects for redraw. + grid_to_screen(ds, g, d->x, d->y, &x, &y); + draw_circle(dr, x, y, 2, COL_FOREGROUND, COL_FOREGROUND); +} + +static int boxes_intersect(int x0, int y0, int w0, int h0, + int x1, int y1, int w1, int h1) +{ + /* + * Two intervals intersect iff neither is wholly on one side of + * the other. Two boxes intersect iff their horizontal and + * vertical intervals both intersect. */ - if (ds->started) { - const char redraw_flag = 1<<7; + return (x0 < x1+w1 && x1 < x0+w0 && y0 < y1+h1 && y1 < y0+h0); +} + +static void game_redraw_in_rect(drawing *dr, game_drawstate *ds, + game_state *state, int x, int y, int w, int h) +{ + grid *g = state->game_grid; + int i, phase; + int bx, by, bw, bh; + + clip(dr, x, y, w, h); + draw_rect(dr, x, y, w, h, COL_BACKGROUND); + + for (i = 0; i < g->num_faces; i++) { + if (state->clues[i] >= 0) { + face_text_bbox(ds, g, &g->faces[i], &bx, &by, &bw, &bh); + if (boxes_intersect(x, y, w, h, bx, by, bw, bh)) + game_redraw_clue(dr, ds, state, i); + } + } + for (phase = 0; phase < NPHASES; phase++) { for (i = 0; i < g->num_edges; i++) { - /* If we're changing state, AND - * the previous state was a coloured line */ - if ((state->lines[i] != (ds->lines[i] & ~redraw_flag)) && - ((ds->lines[i] & ~redraw_flag) != LINE_NO)) { - grid_edge *e = g->edges + i; - int x1 = e->dot1->x; - int y1 = e->dot1->y; - int x2 = e->dot2->x; - int y2 = e->dot2->y; - int xmin, xmax, ymin, ymax; - int j; - grid_to_screen(ds, g, x1, y1, &x1, &y1); - grid_to_screen(ds, g, x2, y2, &x2, &y2); - /* Allow extra margin for dots, and thickness of lines */ - xmin = min(x1, x2) - 2; - xmax = max(x1, x2) + 2; - ymin = min(y1, y2) - 2; - ymax = max(y1, y2) + 2; - /* For testing, I find it helpful to change COL_BACKGROUND - * to COL_SATISFIED here. */ - draw_rect(dr, xmin, ymin, xmax - xmin + 1, ymax - ymin + 1, - COL_BACKGROUND); - draw_update(dr, xmin, ymin, xmax - xmin + 1, ymax - ymin + 1); - - /* Mark nearby lines for redraw */ - for (j = 0; j < e->dot1->order; j++) - ds->lines[e->dot1->edges[j] - g->edges] |= redraw_flag; - for (j = 0; j < e->dot2->order; j++) - ds->lines[e->dot2->edges[j] - g->edges] |= redraw_flag; - /* Mark nearby clues for redraw. Use a value that is - * neither TRUE nor FALSE for this. */ - if (e->face1) - ds->clue_error[e->face1 - g->faces] = 2; - if (e->face2) - ds->clue_error[e->face2 - g->faces] = 2; - } + edge_bbox(ds, g, &g->edges[i], &bx, &by, &bw, &bh); + if (boxes_intersect(x, y, w, h, bx, by, bw, bh)) + game_redraw_line(dr, ds, state, i, phase); } } + for (i = 0; i < g->num_dots; i++) { + dot_bbox(ds, g, &g->dots[i], &bx, &by, &bw, &bh); + if (boxes_intersect(x, y, w, h, bx, by, bw, bh)) + game_redraw_dot(dr, ds, state, i); + } - /* Redraw clue colours if necessary */ - for (i = 0; i < g->num_faces; i++) { - grid_face *f = g->faces + i; - int sides = f->order; - int j; - n = state->clues[i]; - if (n < 0) - continue; + unclip(dr); + draw_update(dr, x, y, w, h); +} - c[0] = CLUE2CHAR(n); - c[1] = '\0'; +static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate, + game_state *state, int dir, game_ui *ui, + float animtime, float flashtime) +{ +#define REDRAW_OBJECTS_LIMIT 16 /* Somewhat arbitrary tradeoff */ - clue_mistake = (face_order(state, i, LINE_YES) > n || - face_order(state, i, LINE_NO ) > (sides-n)); + grid *g = state->game_grid; + int border = BORDER(ds->tilesize); + int i; + int flash_changed; + int redraw_everything = FALSE; - clue_satisfied = (face_order(state, i, LINE_YES) == n && - face_order(state, i, LINE_NO ) == (sides-n)); + int edges[REDRAW_OBJECTS_LIMIT], nedges = 0; + int faces[REDRAW_OBJECTS_LIMIT], nfaces = 0; - if (clue_mistake != ds->clue_error[i] - || clue_satisfied != ds->clue_satisfied[i]) { - int x, y; - face_text_pos(ds, g, f, &x, &y); - /* There seems to be a certain amount of trial-and-error - * involved in working out the correct bounding-box for - * the text. */ - draw_rect(dr, x - ds->tilesize/4 - 1, y - ds->tilesize/4 - 3, - ds->tilesize/2 + 2, ds->tilesize/2 + 5, - COL_BACKGROUND); - draw_text(dr, x, y, - FONT_VARIABLE, ds->tilesize/2, - ALIGN_VCENTRE | ALIGN_HCENTRE, - clue_mistake ? COL_MISTAKE : - clue_satisfied ? COL_SATISFIED : COL_FOREGROUND, c); - draw_update(dr, x - ds->tilesize/4 - 1, y - ds->tilesize/4 - 3, - ds->tilesize/2 + 2, ds->tilesize/2 + 5); + /* Redrawing is somewhat involved. + * + * An update can theoretically affect an arbitrary number of edges + * (consider, for example, completing or breaking a cycle which doesn't + * satisfy all the clues -- we'll switch many edges between error and + * normal states). On the other hand, redrawing the whole grid takes a + * while, making the game feel sluggish, and many updates are actually + * quite well localized. + * + * This redraw algorithm attempts to cope with both situations gracefully + * and correctly. For localized changes, we set a clip rectangle, fill + * it with background, and then redraw (a plausible but conservative + * guess at) the objects which intersect the rectangle; if several + * objects need redrawing, we'll do them individually. However, if lots + * of objects are affected, we'll just redraw everything. + * + * The reason for all of this is that it's just not safe to do the redraw + * piecemeal. If you try to draw an antialiased diagonal line over + * itself, you get a slightly thicker antialiased diagonal line, which + * looks rather ugly after a while. + * + * So, we take two passes over the grid. The first attempts to work out + * what needs doing, and the second actually does it. + */ - ds->clue_error[i] = clue_mistake; - ds->clue_satisfied[i] = clue_satisfied; + if (!ds->started) + redraw_everything = TRUE; + else { + + /* First, trundle through the faces. */ + for (i = 0; i < g->num_faces; i++) { + grid_face *f = g->faces + i; + int sides = f->order; + int clue_mistake; + int clue_satisfied; + int n = state->clues[i]; + if (n < 0) + continue; + + clue_mistake = (face_order(state, i, LINE_YES) > n || + face_order(state, i, LINE_NO ) > (sides-n)); + clue_satisfied = (face_order(state, i, LINE_YES) == n && + face_order(state, i, LINE_NO ) == (sides-n)); + + if (clue_mistake != ds->clue_error[i] || + clue_satisfied != ds->clue_satisfied[i]) { + ds->clue_error[i] = clue_mistake; + ds->clue_satisfied[i] = clue_satisfied; + if (nfaces == REDRAW_OBJECTS_LIMIT) + redraw_everything = TRUE; + else + faces[nfaces++] = i; + } + } - /* Sometimes, the bounding-box encroaches into the surrounding - * lines (particularly if the window is resized fairly small). - * So redraw them. */ - for (j = 0; j < f->order; j++) - ds->lines[f->edges[j] - g->edges] = -1; - } + /* Work out what the flash state needs to be. */ + if (flashtime > 0 && + (flashtime <= FLASH_TIME/3 || + flashtime >= FLASH_TIME*2/3)) { + flash_changed = !ds->flashing; + ds->flashing = TRUE; + } else { + flash_changed = ds->flashing; + ds->flashing = FALSE; + } + + /* Now, trundle through the edges. */ + for (i = 0; i < g->num_edges; i++) { + char new_ds = + state->line_errors[i] ? DS_LINE_ERROR : state->lines[i]; + if (new_ds != ds->lines[i] || + (flash_changed && state->lines[i] == LINE_YES)) { + ds->lines[i] = new_ds; + if (nedges == REDRAW_OBJECTS_LIMIT) + redraw_everything = TRUE; + else + edges[nedges++] = i; + } + } } - /* I've also had a request to colour lines red if they make a non-solution - * loop, or if more than two lines go into any point. I think that would - * be good some time. */ + /* Pass one is now done. Now we do the actual drawing. */ + if (redraw_everything) { + int grid_width = g->highest_x - g->lowest_x; + int grid_height = g->highest_y - g->lowest_y; + int w = grid_width * ds->tilesize / g->tilesize; + int h = grid_height * ds->tilesize / g->tilesize; - /* Lines */ - for (i = 0; i < g->num_edges; i++) { - grid_edge *e = g->edges + i; - int x1, x2, y1, y2; - int xmin, ymin, xmax, ymax; - int need_draw = (state->lines[i] != ds->lines[i]) ? TRUE : FALSE; - if (flash_changed && (state->lines[i] == LINE_YES)) - need_draw = TRUE; - if (!ds->started) - need_draw = TRUE; /* draw everything at the start */ - ds->lines[i] = state->lines[i]; - if (!need_draw) - continue; - if (state->lines[i] == LINE_UNKNOWN) - line_colour = COL_LINEUNKNOWN; - else if (state->lines[i] == LINE_NO) - line_colour = COL_BACKGROUND; - else if (ds->flashing) - line_colour = COL_HIGHLIGHT; - else - line_colour = COL_FOREGROUND; + game_redraw_in_rect(dr, ds, state, + 0, 0, w + 2*border + 1, h + 2*border + 1); + } else { - /* Convert from grid to screen coordinates */ - grid_to_screen(ds, g, e->dot1->x, e->dot1->y, &x1, &y1); - grid_to_screen(ds, g, e->dot2->x, e->dot2->y, &x2, &y2); + /* Right. Now we roll up our sleeves. */ - xmin = min(x1, x2); - xmax = max(x1, x2); - ymin = min(y1, y2); - ymax = max(y1, y2); + for (i = 0; i < nfaces; i++) { + grid_face *f = g->faces + faces[i]; + int x, y, w, h; - if (line_colour != COL_BACKGROUND) { - /* (dx, dy) points roughly from (x1, y1) to (x2, y2). - * The line is then "fattened" in a (roughly) perpendicular - * direction to create a thin rectangle. */ - int dx = (x1 > x2) ? -1 : ((x1 < x2) ? 1 : 0); - int dy = (y1 > y2) ? -1 : ((y1 < y2) ? 1 : 0); - int points[] = { - x1 + dy, y1 - dx, - x1 - dy, y1 + dx, - x2 - dy, y2 + dx, - x2 + dy, y2 - dx - }; - draw_polygon(dr, points, 4, line_colour, line_colour); - } - if (ds->started) { - /* Draw dots at ends of the line */ - draw_circle(dr, x1, y1, 2, COL_FOREGROUND, COL_FOREGROUND); - draw_circle(dr, x2, y2, 2, COL_FOREGROUND, COL_FOREGROUND); - } - draw_update(dr, xmin-2, ymin-2, xmax - xmin + 4, ymax - ymin + 4); - } - - /* Draw dots */ - if (!ds->started) { - for (i = 0; i < g->num_dots; i++) { - grid_dot *d = g->dots + i; - int x, y; - grid_to_screen(ds, g, d->x, d->y, &x, &y); - draw_circle(dr, x, y, 2, COL_FOREGROUND, COL_FOREGROUND); - } + face_text_bbox(ds, g, f, &x, &y, &w, &h); + game_redraw_in_rect(dr, ds, state, x, y, w, h); + } + + for (i = 0; i < nedges; i++) { + grid_edge *e = g->edges + edges[i]; + int x, y, w, h; + + edge_bbox(ds, g, e, &x, &y, &w, &h); + game_redraw_in_rect(dr, ds, state, x, y, w, h); + } } + ds->started = TRUE; } @@ -3225,6 +3780,11 @@ static float game_flash_length(game_state *oldstate, game_state *newstate, return 0.0F; } +static int game_is_solved(game_state *state) +{ + return state->solved; +} + static void game_print_size(game_params *params, float *x, float *y) { int pw, ph; @@ -3244,7 +3804,7 @@ static void game_print(drawing *dr, game_state *state, int tilesize) game_drawstate ads, *ds = &ads; grid *g = state->game_grid; - game_set_size(dr, ds, NULL, tilesize); + ds->tilesize = tilesize; for (i = 0; i < g->num_dots; i++) { int x, y; @@ -3291,14 +3851,14 @@ static void game_print(drawing *dr, game_state *state, int tilesize) dx = (dx * ds->tilesize) / thickness; dy = (dy * ds->tilesize) / thickness; - points[0] = x1 + dy; - points[1] = y1 - dx; - points[2] = x1 - dy; - points[3] = y1 + dx; - points[4] = x2 - dy; - points[5] = y2 + dx; - points[6] = x2 + dy; - points[7] = y2 - dx; + points[0] = x1 + (int)dy; + points[1] = y1 - (int)dx; + points[2] = x1 - (int)dy; + points[3] = y1 + (int)dx; + points[4] = x2 - (int)dy; + points[5] = y2 + (int)dx; + points[6] = x2 + (int)dy; + points[7] = y2 - (int)dx; draw_polygon(dr, points, 4, ink, ink); } else @@ -3351,8 +3911,138 @@ const struct game thegame = { game_redraw, game_anim_length, game_flash_length, + game_is_solved, TRUE, FALSE, game_print_size, game_print, FALSE /* wants_statusbar */, FALSE, game_timing_state, 0, /* mouse_priorities */ }; + +#ifdef STANDALONE_SOLVER + +/* + * Half-hearted standalone solver. It can't output the solution to + * anything but a square puzzle, and it can't log the deductions + * it makes either. But it can solve square puzzles, and more + * importantly it can use its solver to grade the difficulty of + * any puzzle you give it. + */ + +#include + +int main(int argc, char **argv) +{ + game_params *p; + game_state *s; + char *id = NULL, *desc, *err; + int grade = FALSE; + int ret, diff; +#if 0 /* verbose solver not supported here (yet) */ + int really_verbose = FALSE; +#endif + + while (--argc > 0) { + char *p = *++argv; +#if 0 /* verbose solver not supported here (yet) */ + if (!strcmp(p, "-v")) { + really_verbose = TRUE; + } else +#endif + if (!strcmp(p, "-g")) { + grade = 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 [-g | -v] \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); + + /* + * When solving an Easy puzzle, we don't want to bother the + * user with Hard-level deductions. For this reason, we grade + * the puzzle internally before doing anything else. + */ + ret = -1; /* placate optimiser */ + for (diff = 0; diff < DIFF_MAX; diff++) { + solver_state *sstate_new; + solver_state *sstate = new_solver_state((game_state *)s, diff); + + sstate_new = solve_game_rec(sstate); + + if (sstate_new->solver_status == SOLVER_MISTAKE) + ret = 0; + else if (sstate_new->solver_status == SOLVER_SOLVED) + ret = 1; + else + ret = 2; + + free_solver_state(sstate_new); + free_solver_state(sstate); + + if (ret < 2) + break; + } + + if (diff == DIFF_MAX) { + if (grade) + printf("Difficulty rating: harder than Hard, or ambiguous\n"); + else + printf("Unable to find a unique solution\n"); + } else { + if (grade) { + if (ret == 0) + printf("Difficulty rating: impossible (no solution exists)\n"); + else if (ret == 1) + printf("Difficulty rating: %s\n", diffnames[diff]); + } else { + solver_state *sstate_new; + solver_state *sstate = new_solver_state((game_state *)s, diff); + + /* If we supported a verbose solver, we'd set verbosity here */ + + sstate_new = solve_game_rec(sstate); + + if (sstate_new->solver_status == SOLVER_MISTAKE) + printf("Puzzle is inconsistent\n"); + else { + assert(sstate_new->solver_status == SOLVER_SOLVED); + if (s->grid_type == 0) { + fputs(game_text_format(sstate_new->state), stdout); + } else { + printf("Unable to output non-square grids\n"); + } + } + + free_solver_state(sstate_new); + free_solver_state(sstate); + } + } + + return 0; +} + +#endif + +/* vim: set shiftwidth=4 tabstop=8: */