X-Git-Url: https://git.distorted.org.uk/~mdw/sgt/puzzles/blobdiff_plain/ab53eb64790d5bee44525c3a50a420a6816e2495..cbdf34a00c780fff5c06c9d9c24ab7f53d141bbd:/mines.c diff --git a/mines.c b/mines.c index 50ba8f0..6895b2e 100644 --- a/mines.c +++ b/mines.c @@ -25,10 +25,11 @@ enum { NCOLOURS }; -#define TILE_SIZE 20 +#define PREFERRED_TILE_SIZE 20 +#define TILE_SIZE (ds->tilesize) #define BORDER (TILE_SIZE * 3 / 2) -#define HIGHLIGHT_WIDTH 2 -#define OUTER_HIGHLIGHT_WIDTH 3 +#define HIGHLIGHT_WIDTH (TILE_SIZE / 10) +#define OUTER_HIGHLIGHT_WIDTH (BORDER / 10) #define COORD(x) ( (x) * TILE_SIZE + BORDER ) #define FROMCOORD(x) ( ((x) - BORDER + TILE_SIZE) / TILE_SIZE - 1 ) @@ -97,8 +98,11 @@ static game_params *default_params(void) static const struct game_params mines_presets[] = { {9, 9, 10, TRUE}, + {9, 9, 35, TRUE}, {16, 16, 40, TRUE}, + {16, 16, 99, TRUE}, {30, 16, 99, TRUE}, + {30, 16, 170, TRUE}, }; static int game_fetch_preset(int i, char **name, game_params **params) @@ -1291,7 +1295,7 @@ static int minesolve(int w, int h, int n, signed char *grid, */ struct minectx { - signed char *grid; + char *grid; int w, h; int sx, sy; int allow_big_perturbs; @@ -1786,7 +1790,7 @@ static char *minegen(int w, int h, int n, int x, int y, int unique, * We bypass this bit if we're not after a unique grid. */ if (unique) { - signed char *solvegrid = snewn(w*h, char); + signed char *solvegrid = snewn(w*h, signed char); struct minectx actx, *ctx = &actx; int solveret, prevret = -2; @@ -1824,118 +1828,51 @@ static char *minegen(int w, int h, int n, int x, int y, int unique, return ret; } -/* - * The Mines game descriptions contain the location of every mine, - * and can therefore be used to cheat. - * - * It would be pointless to attempt to _prevent_ this form of - * cheating by encrypting the description, since Mines is - * open-source so anyone can find out the encryption key. However, - * I think it is worth doing a bit of gentle obfuscation to prevent - * _accidental_ spoilers: if you happened to note that the game ID - * starts with an F, for example, you might be unable to put the - * knowledge of those mines out of your mind while playing. So, - * just as discussions of film endings are rot13ed to avoid - * spoiling it for people who don't want to be told, we apply a - * keyless, reversible, but visually completely obfuscatory masking - * function to the mine bitmap. - */ -static void obfuscate_bitmap(unsigned char *bmp, int bits, int decode) +static char *describe_layout(char *grid, int area, int x, int y, + int obfuscate) { - int bytes, firsthalf, secondhalf; - struct step { - unsigned char *seedstart; - int seedlen; - unsigned char *targetstart; - int targetlen; - } steps[2]; - int i, j; + char *ret, *p; + unsigned char *bmp; + int i; /* - * My obfuscation algorithm is similar in concept to the OAEP - * encoding used in some forms of RSA. Here's a specification - * of it: - * - * + We have a `masking function' which constructs a stream of - * pseudorandom bytes from a seed of some number of input - * bytes. - * - * + We pad out our input bit stream to a whole number of - * bytes by adding up to 7 zero bits on the end. (In fact - * the bitmap passed as input to this function will already - * have had this done in practice.) - * - * + We divide the _byte_ stream exactly in half, rounding the - * half-way position _down_. So an 81-bit input string, for - * example, rounds up to 88 bits or 11 bytes, and then - * dividing by two gives 5 bytes in the first half and 6 in - * the second half. - * - * + We generate a mask from the second half of the bytes, and - * XOR it over the first half. - * - * + We generate a mask from the (encoded) first half of the - * bytes, and XOR it over the second half. Any null bits at - * the end which were added as padding are cleared back to - * zero even if this operation would have made them nonzero. - * - * To de-obfuscate, the steps are precisely the same except - * that the final two are reversed. - * - * Finally, our masking function. Given an input seed string of - * bytes, the output mask consists of concatenating the SHA-1 - * hashes of the seed string and successive decimal integers, - * starting from 0. + * Set up the mine bitmap and obfuscate it. */ + bmp = snewn((area + 7) / 8, unsigned char); + memset(bmp, 0, (area + 7) / 8); + for (i = 0; i < area; i++) { + if (grid[i]) + bmp[i / 8] |= 0x80 >> (i % 8); + } + if (obfuscate) + obfuscate_bitmap(bmp, area, FALSE); - bytes = (bits + 7) / 8; - firsthalf = bytes / 2; - secondhalf = bytes - firsthalf; - - steps[decode ? 1 : 0].seedstart = bmp + firsthalf; - steps[decode ? 1 : 0].seedlen = secondhalf; - steps[decode ? 1 : 0].targetstart = bmp; - steps[decode ? 1 : 0].targetlen = firsthalf; - - steps[decode ? 0 : 1].seedstart = bmp; - steps[decode ? 0 : 1].seedlen = firsthalf; - steps[decode ? 0 : 1].targetstart = bmp + firsthalf; - steps[decode ? 0 : 1].targetlen = secondhalf; - - for (i = 0; i < 2; i++) { - SHA_State base, final; - unsigned char digest[20]; - char numberbuf[80]; - int digestpos = 20, counter = 0; - - SHA_Init(&base); - SHA_Bytes(&base, steps[i].seedstart, steps[i].seedlen); - - for (j = 0; j < steps[i].targetlen; j++) { - if (digestpos >= 20) { - sprintf(numberbuf, "%d", counter++); - final = base; - SHA_Bytes(&final, numberbuf, strlen(numberbuf)); - SHA_Final(&final, digest); - digestpos = 0; - } - steps[i].targetstart[j] ^= digest[digestpos++]; - } - - /* - * Mask off the pad bits in the final byte after both steps. - */ - if (bits % 8) - bmp[bits / 8] &= 0xFF & (0xFF00 >> (bits % 8)); + /* + * Now encode the resulting bitmap in hex. We can work to + * nibble rather than byte granularity, since the obfuscation + * function guarantees to return a bit string of the same + * length as its input. + */ + ret = snewn((area+3)/4 + 100, char); + p = ret + sprintf(ret, "%d,%d,%s", x, y, + obfuscate ? "m" : ""); /* 'm' == masked */ + for (i = 0; i < (area+3)/4; i++) { + int v = bmp[i/2]; + if (i % 2 == 0) + v >>= 4; + *p++ = "0123456789abcdef"[v & 0xF]; } + *p = '\0'; + + sfree(bmp); + + return ret; } static char *new_mine_layout(int w, int h, int n, int x, int y, int unique, random_state *rs, char **game_desc) { - signed char *grid, *ret, *p; - unsigned char *bmp; - int i, area; + char *grid; #ifdef TEST_OBFUSCATION static int tested_obfuscation = FALSE; @@ -2002,39 +1939,8 @@ static char *new_mine_layout(int w, int h, int n, int x, int y, int unique, grid = minegen(w, h, n, x, y, unique, rs); - if (game_desc) { - /* - * Set up the mine bitmap and obfuscate it. - */ - area = w * h; - bmp = snewn((area + 7) / 8, unsigned char); - memset(bmp, 0, (area + 7) / 8); - for (i = 0; i < area; i++) { - if (grid[i]) - bmp[i / 8] |= 0x80 >> (i % 8); - } - obfuscate_bitmap(bmp, area, FALSE); - - /* - * Now encode the resulting bitmap in hex. We can work to - * nibble rather than byte granularity, since the obfuscation - * function guarantees to return a bit string of the same - * length as its input. - */ - ret = snewn((area+3)/4 + 100, char); - p = ret + sprintf(ret, "%d,%d,m", x, y); /* 'm' == masked */ - for (i = 0; i < (area+3)/4; i++) { - int v = bmp[i/2]; - if (i % 2 == 0) - v >>= 4; - *p++ = "0123456789abcdef"[v & 0xF]; - } - *p = '\0'; - - sfree(bmp); - - *game_desc = ret; - } + if (game_desc) + *game_desc = describe_layout(grid, w * h, x, y, TRUE); return grid; } @@ -2060,7 +1966,7 @@ static char *new_game_desc(game_params *params, random_state *rs, /* * For batch-generated grids, pre-open one square. */ - signed char *grid; + char *grid; char *desc; grid = new_mine_layout(params->w, params->h, params->n, @@ -2262,7 +2168,7 @@ static game_state *new_game(midend_data *me, game_params *params, char *desc) memset(state->layout, 0, sizeof(struct mine_layout)); state->layout->refcount = 1; - state->grid = snewn(wh, char); + state->grid = snewn(wh, signed char); memset(state->grid, -2, wh); if (*desc == 'r') { @@ -2355,7 +2261,7 @@ static game_state *dup_game(game_state *state) ret->just_used_solve = state->just_used_solve; ret->layout = state->layout; ret->layout->refcount++; - ret->grid = snewn(ret->w * ret->h, char); + ret->grid = snewn(ret->w * ret->h, signed char); memcpy(ret->grid, state->grid, ret->w * ret->h); return ret; @@ -2373,8 +2279,8 @@ static void free_game(game_state *state) sfree(state); } -static game_state *solve_game(game_state *state, game_aux_info *aux, - char **error) +static game_state *solve_game(game_state *state, game_state *currstate, + game_aux_info *aux, char **error) { /* * Simply expose the entire grid as if it were a completed @@ -2464,6 +2370,26 @@ static void free_ui(game_ui *ui) sfree(ui); } +static void game_changed_state(game_ui *ui, game_state *oldstate, + game_state *newstate) +{ +} + +struct game_drawstate { + int w, h, started, tilesize; + signed char *grid; + /* + * Items in this `grid' array have all the same values as in + * the game_state grid, and in addition: + * + * - -10 means the tile was drawn `specially' as a result of a + * flash, so it will always need redrawing. + * + * - -22 and -23 mean the tile is highlighted for a possible + * click. + */ +}; + static game_state *make_move(game_state *from, game_ui *ui, game_drawstate *ds, int x, int y, int button) { @@ -2479,11 +2405,12 @@ static game_state *make_move(game_state *from, game_ui *ui, game_drawstate *ds, cx = FROMCOORD(x); cy = FROMCOORD(y); - if (cx < 0 || cx >= from->w || cy < 0 || cy >= from->h) - return NULL; if (button == LEFT_BUTTON || button == LEFT_DRAG || button == MIDDLE_BUTTON || button == MIDDLE_DRAG) { + if (cx < 0 || cx >= from->w || cy < 0 || cy >= from->h) + return NULL; + /* * Mouse-downs and mouse-drags just cause highlighting * updates. @@ -2495,6 +2422,9 @@ static game_state *make_move(game_state *from, game_ui *ui, game_drawstate *ds, } if (button == RIGHT_BUTTON) { + if (cx < 0 || cx >= from->w || cy < 0 || cy >= from->h) + return NULL; + /* * Right-clicking only works on a covered square, and it * toggles between -1 (marked as mine) and -2 (not marked @@ -2521,6 +2451,8 @@ static game_state *make_move(game_state *from, game_ui *ui, game_drawstate *ds, * At this stage we must never return NULL: we have adjusted * the ui, so at worst we return `from'. */ + if (cx < 0 || cx >= from->w || cy < 0 || cy >= from->h) + return from; /* * Left-clicking on a covered square opens a tile. Not @@ -2583,23 +2515,23 @@ static game_state *make_move(game_state *from, game_ui *ui, game_drawstate *ds, * Drawing routines. */ -struct game_drawstate { - int w, h, started; - signed char *grid; +static void game_size(game_params *params, game_drawstate *ds, + int *x, int *y, int expand) +{ + int tsx, tsy, ts; /* - * Items in this `grid' array have all the same values as in - * the game_state grid, and in addition: - * - * - -10 means the tile was drawn `specially' as a result of a - * flash, so it will always need redrawing. - * - * - -22 and -23 mean the tile is highlighted for a possible - * click. + * Each window dimension equals the tile size times 3 more than + * the grid dimension (the border is 3/2 the width of the + * tiles). */ -}; + tsx = *x / (params->w + 3); + tsy = *y / (params->h + 3); + ts = min(tsx, tsy); + if (expand) + ds->tilesize = ts; + else + ds->tilesize = min(ts, PREFERRED_TILE_SIZE); -static void game_size(game_params *params, int *x, int *y) -{ *x = BORDER * 2 + TILE_SIZE * params->w; *y = BORDER * 2 + TILE_SIZE * params->h; } @@ -2689,7 +2621,8 @@ static game_drawstate *game_new_drawstate(game_state *state) ds->w = state->w; ds->h = state->h; ds->started = FALSE; - ds->grid = snewn(ds->w * ds->h, char); + ds->tilesize = 0; /* not decided yet */ + ds->grid = snewn(ds->w * ds->h, signed char); memset(ds->grid, -99, ds->w * ds->h); @@ -2702,7 +2635,8 @@ static void game_free_drawstate(game_drawstate *ds) sfree(ds); } -static void draw_tile(frontend *fe, int x, int y, int v, int bg) +static void draw_tile(frontend *fe, game_drawstate *ds, + int x, int y, int v, int bg) { if (v < 0) { int coords[12]; @@ -2936,7 +2870,7 @@ static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate, v -= 20; if (ds->grid[y*ds->w+x] != v || bg != COL_BACKGROUND) { - draw_tile(fe, COORD(x), COORD(y), v, bg); + draw_tile(fe, ds, COORD(x), COORD(y), v, bg); ds->grid[y*ds->w+x] = (bg == COL_BACKGROUND ? v : -10); } } @@ -3027,6 +2961,7 @@ const struct game thegame = { TRUE, game_text_format, new_ui, free_ui, + game_changed_state, make_move, game_size, game_colours, @@ -3039,3 +2974,108 @@ const struct game thegame = { TRUE, game_timing_state, BUTTON_BEATS(LEFT_BUTTON, RIGHT_BUTTON), }; + +#ifdef STANDALONE_OBFUSCATOR + +/* + * Vaguely useful stand-alone program which translates between + * obfuscated and clear Mines game descriptions. Pass in a game + * description on the command line, and if it's clear it will be + * obfuscated and vice versa. The output text should also be a + * valid game ID describing the same game. Like this: + * + * $ ./mineobfusc 9x9:4,4,mb071b49fbd1cb6a0d5868 + * 9x9:4,4,004000007c00010022080 + * $ ./mineobfusc 9x9:4,4,004000007c00010022080 + * 9x9:4,4,mb071b49fbd1cb6a0d5868 + * + * gcc -DSTANDALONE_OBFUSCATOR -o mineobfusc mines.c malloc.c random.c tree234.c + */ + +#include + +void frontend_default_colour(frontend *fe, float *output) {} +void draw_text(frontend *fe, int x, int y, int fonttype, int fontsize, + int align, int colour, char *text) {} +void draw_rect(frontend *fe, int x, int y, int w, int h, int colour) {} +void draw_line(frontend *fe, int x1, int y1, int x2, int y2, int colour) {} +void draw_polygon(frontend *fe, int *coords, int npoints, + int fill, int colour) {} +void clip(frontend *fe, int x, int y, int w, int h) {} +void unclip(frontend *fe) {} +void start_draw(frontend *fe) {} +void draw_update(frontend *fe, int x, int y, int w, int h) {} +void end_draw(frontend *fe) {} +void midend_supersede_game_desc(midend_data *me, char *desc) {} +void status_bar(frontend *fe, char *text) {} + +void fatal(char *fmt, ...) +{ + va_list ap; + + fprintf(stderr, "fatal error: "); + + va_start(ap, fmt); + vfprintf(stderr, fmt, ap); + va_end(ap); + + fprintf(stderr, "\n"); + exit(1); +} + +int main(int argc, char **argv) +{ + game_params *p; + game_state *s; + int recurse = TRUE; + char *id = NULL, *desc, *err; + int y, x; + int grade = FALSE; + + while (--argc > 0) { + char *p = *++argv; + if (*p == '-') { + fprintf(stderr, "%s: unrecognised option `%s'\n", argv[0]); + return 1; + } else { + id = p; + } + } + + if (!id) { + fprintf(stderr, "usage: %s \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); + + x = atoi(desc); + while (*desc && *desc != ',') desc++; + if (*desc) desc++; + y = atoi(desc); + while (*desc && *desc != ',') desc++; + if (*desc) desc++; + + printf("%s:%s\n", id, describe_layout(s->layout->mines, + p->w * p->h, + x, y, + (*desc != 'm'))); + + return 0; +} + +#endif