ref: 90e2c7539be4fce1b6dad397109f3c4927db1594
dir: /net.c/
/* * net.c: Net game. */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <assert.h> #include <ctype.h> #include <limits.h> #include <math.h> #include "puzzles.h" #include "tree234.h" /* * The standard user interface for Net simply has left- and * right-button mouse clicks in a square rotate it one way or the * other. We also provide, by #ifdef, a separate interface based on * rotational dragging motions. I initially developed this for the * Mac on the basis that it might work better than the click * interface with only one mouse button available, but in fact * found it to be quite strange and unintuitive. Apparently it * works better on stylus-driven platforms such as Palm and * PocketPC, though, so we enable it by default there. */ #ifdef STYLUS_BASED #define USE_DRAGGING #endif /* Direction and other bitfields */ #define R 0x01 #define U 0x02 #define L 0x04 #define D 0x08 #define LOCKED 0x10 #define ACTIVE 0x20 #define RERR (R << 6) #define UERR (U << 6) #define LERR (L << 6) #define DERR (D << 6) #define ERR(dir) ((dir) << 6) /* Rotations: Anticlockwise, Clockwise, Flip, general rotate */ #define A(x) ( (((x) & 0x07) << 1) | (((x) & 0x08) >> 3) ) #define C(x) ( (((x) & 0x0E) >> 1) | (((x) & 0x01) << 3) ) #define F(x) ( (((x) & 0x0C) >> 2) | (((x) & 0x03) << 2) ) #define ROT(x, n) ( ((n)&3) == 0 ? (x) : \ ((n)&3) == 1 ? A(x) : \ ((n)&3) == 2 ? F(x) : C(x) ) /* X and Y displacements */ #define X(x) ( (x) == R ? +1 : (x) == L ? -1 : 0 ) #define Y(x) ( (x) == D ? +1 : (x) == U ? -1 : 0 ) /* Bit count */ #define COUNT(x) ( (((x) & 0x08) >> 3) + (((x) & 0x04) >> 2) + \ (((x) & 0x02) >> 1) + ((x) & 0x01) ) #define PREFERRED_TILE_SIZE 32 #define TILE_SIZE (ds->tilesize) #define LINE_THICK ((TILE_SIZE+47)/48) #ifdef SMALL_SCREEN #define WINDOW_OFFSET 4 #else #define WINDOW_OFFSET 16 #endif #define ROTATE_TIME 0.13F #define FLASH_FRAME 0.07F enum { COL_BACKGROUND, COL_LOCKED, COL_BORDER, COL_WIRE, COL_ENDPOINT, COL_POWERED, COL_BARRIER, COL_ERR, NCOLOURS }; struct game_params { int width; int height; bool wrapping; bool unique; float barrier_probability; }; typedef struct game_immutable_state { int refcount; unsigned char *barriers; } game_immutable_state; struct game_state { int width, height; bool wrapping, completed; int last_rotate_x, last_rotate_y, last_rotate_dir; bool used_solve; unsigned char *tiles; struct game_immutable_state *imm; }; #define OFFSETWH(x2,y2,x1,y1,dir,width,height) \ ( (x2) = ((x1) + width + X((dir))) % width, \ (y2) = ((y1) + height + Y((dir))) % height) #define OFFSET(x2,y2,x1,y1,dir,state) \ OFFSETWH(x2,y2,x1,y1,dir,(state)->width,(state)->height) #define index(state, a, x, y) ( a[(y) * (state)->width + (x)] ) #define tile(state, x, y) index(state, (state)->tiles, x, y) #define barrier(state, x, y) index(state, (state)->imm->barriers, x, y) struct xyd { int x, y, direction; }; static int xyd_cmp(const void *av, const void *bv) { const struct xyd *a = (const struct xyd *)av; const struct xyd *b = (const struct xyd *)bv; if (a->x < b->x) return -1; if (a->x > b->x) return +1; if (a->y < b->y) return -1; if (a->y > b->y) return +1; if (a->direction < b->direction) return -1; if (a->direction > b->direction) return +1; return 0; } static int xyd_cmp_nc(void *av, void *bv) { return xyd_cmp(av, bv); } static struct xyd *new_xyd(int x, int y, int direction) { struct xyd *xyd = snew(struct xyd); xyd->x = x; xyd->y = y; xyd->direction = direction; return xyd; } /* ---------------------------------------------------------------------- * Manage game parameters. */ static game_params *default_params(void) { game_params *ret = snew(game_params); ret->width = 5; ret->height = 5; ret->wrapping = false; ret->unique = true; ret->barrier_probability = 0.0; return ret; } static const struct game_params net_presets[] = { {5, 5, false, true, 0.0}, {7, 7, false, true, 0.0}, {9, 9, false, true, 0.0}, {11, 11, false, true, 0.0}, #ifndef SMALL_SCREEN {13, 11, false, true, 0.0}, #endif {5, 5, true, true, 0.0}, {7, 7, true, true, 0.0}, {9, 9, true, true, 0.0}, {11, 11, true, true, 0.0}, #ifndef SMALL_SCREEN {13, 11, true, true, 0.0}, #endif }; static bool game_fetch_preset(int i, char **name, game_params **params) { game_params *ret; char str[80]; if (i < 0 || i >= lenof(net_presets)) return false; ret = snew(game_params); *ret = net_presets[i]; sprintf(str, "%dx%d%s", ret->width, ret->height, ret->wrapping ? " wrapping" : ""); *name = dupstr(str); *params = ret; return true; } static void free_params(game_params *params) { sfree(params); } static game_params *dup_params(const game_params *params) { game_params *ret = snew(game_params); *ret = *params; /* structure copy */ return ret; } static void decode_params(game_params *ret, char const *string) { char const *p = string; ret->width = atoi(p); while (*p && isdigit((unsigned char)*p)) p++; if (*p == 'x') { p++; ret->height = atoi(p); while (*p && isdigit((unsigned char)*p)) p++; } else { ret->height = ret->width; } while (*p) { if (*p == 'w') { p++; ret->wrapping = true; } else if (*p == 'b') { p++; ret->barrier_probability = (float)atof(p); while (*p && (*p == '.' || isdigit((unsigned char)*p))) p++; } else if (*p == 'a') { p++; ret->unique = false; } else p++; /* skip any other gunk */ } } static char *encode_params(const game_params *params, bool full) { char ret[400]; int len; len = sprintf(ret, "%dx%d", params->width, params->height); if (params->wrapping) ret[len++] = 'w'; if (full && params->barrier_probability) len += sprintf(ret+len, "b%g", params->barrier_probability); if (full && !params->unique) ret[len++] = 'a'; assert(len < lenof(ret)); ret[len] = '\0'; return dupstr(ret); } static config_item *game_configure(const game_params *params) { config_item *ret; char buf[80]; ret = snewn(6, config_item); ret[0].name = "Width"; ret[0].type = C_STRING; sprintf(buf, "%d", params->width); ret[0].u.string.sval = dupstr(buf); ret[1].name = "Height"; ret[1].type = C_STRING; sprintf(buf, "%d", params->height); ret[1].u.string.sval = dupstr(buf); ret[2].name = "Walls wrap around"; ret[2].type = C_BOOLEAN; ret[2].u.boolean.bval = params->wrapping; ret[3].name = "Barrier probability"; ret[3].type = C_STRING; sprintf(buf, "%g", params->barrier_probability); ret[3].u.string.sval = dupstr(buf); ret[4].name = "Ensure unique solution"; ret[4].type = C_BOOLEAN; ret[4].u.boolean.bval = params->unique; ret[5].name = NULL; ret[5].type = C_END; return ret; } static game_params *custom_params(const config_item *cfg) { game_params *ret = snew(game_params); ret->width = atoi(cfg[0].u.string.sval); ret->height = atoi(cfg[1].u.string.sval); ret->wrapping = cfg[2].u.boolean.bval; ret->barrier_probability = (float)atof(cfg[3].u.string.sval); ret->unique = cfg[4].u.boolean.bval; return ret; } static const char *validate_params(const game_params *params, bool full) { if (params->width <= 0 || params->height <= 0) return "Width and height must both be greater than zero"; if (params->width <= 1 && params->height <= 1) return "At least one of width and height must be greater than one"; if (params->width > INT_MAX / params->height) return "Width times height must not be unreasonably large"; if (params->barrier_probability < 0) return "Barrier probability may not be negative"; if (params->barrier_probability > 1) return "Barrier probability may not be greater than 1"; /* * Specifying either grid dimension as 2 in a wrapping puzzle * makes it actually impossible to ensure a unique puzzle * solution. * * Proof: * * Without loss of generality, let us assume the puzzle _width_ * is 2, so we can conveniently discuss rows without having to * say `rows/columns' all the time. (The height may be 2 as * well, but that doesn't matter.) * * In each row, there are two edges between tiles: the inner * edge (running down the centre of the grid) and the outer * edge (the identified left and right edges of the grid). * * Lemma: In any valid 2xn puzzle there must be at least one * row in which _exactly one_ of the inner edge and outer edge * is connected. * * Proof: No row can have _both_ inner and outer edges * connected, because this would yield a loop. So the only * other way to falsify the lemma is for every row to have * _neither_ the inner nor outer edge connected. But this * means there is no connection at all between the left and * right columns of the puzzle, so there are two disjoint * subgraphs, which is also disallowed. [] * * Given such a row, it is always possible to make the * disconnected edge connected and the connected edge * disconnected without changing the state of any other edge. * (This is easily seen by case analysis on the various tiles: * left-pointing and right-pointing endpoints can be exchanged, * likewise T-pieces, and a corner piece can select its * horizontal connectivity independently of its vertical.) This * yields a distinct valid solution. * * Thus, for _every_ row in which exactly one of the inner and * outer edge is connected, there are two valid states for that * row, and hence the total number of solutions of the puzzle * is at least 2^(number of such rows), and in particular is at * least 2 since there must be at least one such row. [] */ if (full && params->unique && params->wrapping && (params->width == 2 || params->height == 2)) return "No wrapping puzzle with a width or height of 2 can have" " a unique solution"; return NULL; } /* ---------------------------------------------------------------------- * Solver used to assure solution uniqueness during generation. */ /* * Test cases I used while debugging all this were * * ./net --generate 1 13x11w#12300 * which expands under the non-unique grid generation rules to * 13x11w:5eaade1bd222664436d5e2965c12656b1129dd825219e3274d558d5eb2dab5da18898e571d5a2987be79746bd95726c597447d6da96188c513add829da7681da954db113d3cd244 * and has two ambiguous areas. * * An even better one is * 13x11w#507896411361192 * which expands to * 13x11w:b7125b1aec598eb31bd58d82572bc11494e5dee4e8db2bdd29b88d41a16bdd996d2996ddec8c83741a1e8674e78328ba71737b8894a9271b1cd1399453d1952e43951d9b712822e * and has an ambiguous area _and_ a situation where loop avoidance * is a necessary deductive technique. * * Then there's * 48x25w#820543338195187 * becoming * 48x25w:255989d14cdd185deaa753a93821a12edc1ab97943ac127e2685d7b8b3c48861b2192416139212b316eddd35de43714ebc7628d753db32e596284d9ec52c5a7dc1b4c811a655117d16dc28921b2b4161352cab1d89d18bc836b8b891d55ea4622a1251861b5bc9a8aa3e5bcd745c95229ca6c3b5e21d5832d397e917325793d7eb442dc351b2db2a52ba8e1651642275842d8871d5534aabc6d5b741aaa2d48ed2a7dbbb3151ddb49d5b9a7ed1ab98ee75d613d656dbba347bc514c84556b43a9bc65a3256ead792488b862a9d2a8a39b4255a4949ed7dbd79443292521265896b4399c95ede89d7c8c797a6a57791a849adea489359a158aa12e5dacce862b8333b7ebea7d344d1a3c53198864b73a9dedde7b663abb1b539e1e8853b1b7edb14a2a17ebaae4dbe63598a2e7e9a2dbdad415bc1d8cb88cbab5a8c82925732cd282e641ea3bd7d2c6e776de9117a26be86deb7c82c89524b122cb9397cd1acd2284e744ea62b9279bae85479ababe315c3ac29c431333395b24e6a1e3c43a2da42d4dce84aadd5b154aea555eaddcbd6e527d228c19388d9b424d94214555a7edbdeebe569d4a56dc51a86bd9963e377bb74752bd5eaa5761ba545e297b62a1bda46ab4aee423ad6c661311783cc18786d4289236563cb4a75ec67d481c14814994464cd1b87396dee63e5ab6e952cc584baa1d4c47cb557ec84dbb63d487c8728118673a166846dd3a4ebc23d6cb9c5827d96b4556e91899db32b517eda815ae271a8911bd745447121dc8d321557bc2a435ebec1bbac35b1a291669451174e6aa2218a4a9c5a6ca31ebc45d84e3a82c121e9ced7d55e9a * which has a spot (far right) where slightly more complex loop * avoidance is required. */ struct todo { bool *marked; int *buffer; int buflen; int head, tail; }; static struct todo *todo_new(int maxsize) { struct todo *todo = snew(struct todo); todo->marked = snewn(maxsize, bool); memset(todo->marked, 0, maxsize); todo->buflen = maxsize + 1; todo->buffer = snewn(todo->buflen, int); todo->head = todo->tail = 0; return todo; } static void todo_free(struct todo *todo) { sfree(todo->marked); sfree(todo->buffer); sfree(todo); } static void todo_add(struct todo *todo, int index) { if (todo->marked[index]) return; /* already on the list */ todo->marked[index] = true; todo->buffer[todo->tail++] = index; if (todo->tail == todo->buflen) todo->tail = 0; } static int todo_get(struct todo *todo) { int ret; if (todo->head == todo->tail) return -1; /* list is empty */ ret = todo->buffer[todo->head++]; if (todo->head == todo->buflen) todo->head = 0; todo->marked[ret] = false; return ret; } /* * Return values: -1 means puzzle was proved inconsistent, 0 means we * failed to narrow down to a unique solution, +1 means we solved it * fully. */ static int net_solver(int w, int h, unsigned char *tiles, unsigned char *barriers, bool wrapping) { unsigned char *tilestate; unsigned char *edgestate; int *deadends; int *equivalence; struct todo *todo; int i, j, x, y; int area; bool done_something; /* * Set up the solver's data structures. */ /* * tilestate stores the possible orientations of each tile. * There are up to four of these, so we'll index the array in * fours. tilestate[(y * w + x) * 4] and its three successive * members give the possible orientations, clearing to 255 from * the end as things are ruled out. * * In this loop we also count up the area of the grid (which is * not _necessarily_ equal to w*h, because there might be one * or more blank squares present. This will never happen in a * grid generated _by_ this program, but it's worth keeping the * solver as general as possible.) */ tilestate = snewn(w * h * 4, unsigned char); area = 0; for (i = 0; i < w*h; i++) { tilestate[i * 4] = tiles[i] & 0xF; for (j = 1; j < 4; j++) { if (tilestate[i * 4 + j - 1] == 255 || A(tilestate[i * 4 + j - 1]) == tilestate[i * 4]) tilestate[i * 4 + j] = 255; else tilestate[i * 4 + j] = A(tilestate[i * 4 + j - 1]); } if (tiles[i] != 0) area++; } /* * edgestate stores the known state of each edge. It is 0 for * unknown, 1 for open (connected) and 2 for closed (not * connected). * * In principle we need only worry about each edge once each, * but in fact it's easier to track each edge twice so that we * can reference it from either side conveniently. Also I'm * going to allocate _five_ bytes per tile, rather than the * obvious four, so that I can index edgestate[(y*w+x) * 5 + d] * where d is 1,2,4,8 and they never overlap. */ edgestate = snewn((w * h - 1) * 5 + 9, unsigned char); memset(edgestate, 0, (w * h - 1) * 5 + 9); /* * deadends tracks which edges have dead ends on them. It is * indexed by tile and direction: deadends[(y*w+x) * 5 + d] * tells you whether heading out of tile (x,y) in direction d * can reach a limited amount of the grid. Values are area+1 * (no dead end known) or less than that (can reach _at most_ * this many other tiles by heading this way out of this tile). */ deadends = snewn((w * h - 1) * 5 + 9, int); for (i = 0; i < (w * h - 1) * 5 + 9; i++) deadends[i] = area+1; /* * equivalence tracks which sets of tiles are known to be * connected to one another, so we can avoid creating loops by * linking together tiles which are already linked through * another route. * * This is a disjoint set forest structure: equivalence[i] * contains the index of another member of the equivalence * class containing i, or contains i itself for precisely one * member in each such class. To find a representative member * of the equivalence class containing i, you keep replacing i * with equivalence[i] until it stops changing; then you go * _back_ along the same path and point everything on it * directly at the representative member so as to speed up * future searches. Then you test equivalence between tiles by * finding the representative of each tile and seeing if * they're the same; and you create new equivalence (merge * classes) by finding the representative of each tile and * setting equivalence[one]=the_other. */ equivalence = snew_dsf(w * h); /* * On a non-wrapping grid, we instantly know that all the edges * round the edge are closed. */ if (!wrapping) { for (i = 0; i < w; i++) { edgestate[i * 5 + 2] = edgestate[((h-1) * w + i) * 5 + 8] = 2; } for (i = 0; i < h; i++) { edgestate[(i * w + w-1) * 5 + 1] = edgestate[(i * w) * 5 + 4] = 2; } } /* * If we have barriers available, we can mark those edges as * closed too. */ if (barriers) { for (y = 0; y < h; y++) for (x = 0; x < w; x++) { int d; for (d = 1; d <= 8; d += d) { if (barriers[y*w+x] & d) { int x2, y2; /* * In principle the barrier list should already * contain each barrier from each side, but * let's not take chances with our internal * consistency. */ OFFSETWH(x2, y2, x, y, d, w, h); edgestate[(y*w+x) * 5 + d] = 2; edgestate[(y2*w+x2) * 5 + F(d)] = 2; } } } } /* * Since most deductions made by this solver are local (the * exception is loop avoidance, where joining two tiles * together on one side of the grid can theoretically permit a * fresh deduction on the other), we can address the scaling * problem inherent in iterating repeatedly over the entire * grid by instead working with a to-do list. */ todo = todo_new(w * h); /* * Main deductive loop. */ done_something = true; /* prevent instant termination! */ while (1) { int index; /* * Take a tile index off the todo list and process it. */ index = todo_get(todo); if (index == -1) { /* * If we have run out of immediate things to do, we * have no choice but to scan the whole grid for * longer-range things we've missed. Hence, I now add * every square on the grid back on to the to-do list. * I also set `done_something' to false at this point; * if we later come back here and find it still false, * we will know we've scanned the entire grid without * finding anything new to do, and we can terminate. */ if (!done_something) break; for (i = 0; i < w*h; i++) todo_add(todo, i); done_something = false; index = todo_get(todo); } y = index / w; x = index % w; { int d, ourclass = dsf_canonify(equivalence, y*w+x); int deadendmax[9]; deadendmax[1] = deadendmax[2] = deadendmax[4] = deadendmax[8] = 0; for (i = j = 0; i < 4 && tilestate[(y*w+x) * 4 + i] != 255; i++) { bool valid; int nnondeadends, nondeadends[4], deadendtotal; int nequiv, equiv[5]; int val = tilestate[(y*w+x) * 4 + i]; valid = true; nnondeadends = deadendtotal = 0; equiv[0] = ourclass; nequiv = 1; for (d = 1; d <= 8; d += d) { /* * Immediately rule out this orientation if it * conflicts with any known edge. */ if ((edgestate[(y*w+x) * 5 + d] == 1 && !(val & d)) || (edgestate[(y*w+x) * 5 + d] == 2 && (val & d))) valid = false; if (val & d) { /* * Count up the dead-end statistics. */ if (deadends[(y*w+x) * 5 + d] <= area) { deadendtotal += deadends[(y*w+x) * 5 + d]; } else { nondeadends[nnondeadends++] = d; } /* * Ensure we aren't linking to any tiles, * through edges not already known to be * open, which create a loop. */ if (edgestate[(y*w+x) * 5 + d] == 0) { int c, k, x2, y2; OFFSETWH(x2, y2, x, y, d, w, h); c = dsf_canonify(equivalence, y2*w+x2); for (k = 0; k < nequiv; k++) if (c == equiv[k]) break; if (k == nequiv) equiv[nequiv++] = c; else valid = false; } } } if (nnondeadends == 0) { /* * If this orientation links together dead-ends * with a total area of less than the entire * grid, it is invalid. * * (We add 1 to deadendtotal because of the * tile itself, of course; one tile linking * dead ends of size 2 and 3 forms a subnetwork * with a total area of 6, not 5.) */ if (deadendtotal > 0 && deadendtotal+1 < area) valid = false; } else if (nnondeadends == 1) { /* * If this orientation links together one or * more dead-ends with precisely one * non-dead-end, then we may have to mark that * non-dead-end as a dead end going the other * way. However, it depends on whether all * other orientations share the same property. */ deadendtotal++; if (deadendmax[nondeadends[0]] < deadendtotal) deadendmax[nondeadends[0]] = deadendtotal; } else { /* * If this orientation links together two or * more non-dead-ends, then we can rule out the * possibility of putting in new dead-end * markings in those directions. */ int k; for (k = 0; k < nnondeadends; k++) deadendmax[nondeadends[k]] = area+1; } if (valid) tilestate[(y*w+x) * 4 + j++] = val; #ifdef SOLVER_DIAGNOSTICS else printf("ruling out orientation %x at %d,%d\n", val, x, y); #endif } if (j == 0) { /* If we've ruled out all possible orientations for a * tile, then our puzzle has no solution at all. */ return -1; } if (j < i) { done_something = true; /* * We have ruled out at least one tile orientation. * Make sure the rest are blanked. */ while (j < 4) tilestate[(y*w+x) * 4 + j++] = 255; } /* * Now go through the tile orientations again and see * if we've deduced anything new about any edges. */ { int a, o; a = 0xF; o = 0; for (i = 0; i < 4 && tilestate[(y*w+x) * 4 + i] != 255; i++) { a &= tilestate[(y*w+x) * 4 + i]; o |= tilestate[(y*w+x) * 4 + i]; } for (d = 1; d <= 8; d += d) if (edgestate[(y*w+x) * 5 + d] == 0) { int x2, y2, d2; OFFSETWH(x2, y2, x, y, d, w, h); d2 = F(d); if (a & d) { /* This edge is open in all orientations. */ #ifdef SOLVER_DIAGNOSTICS printf("marking edge %d,%d:%d open\n", x, y, d); #endif edgestate[(y*w+x) * 5 + d] = 1; edgestate[(y2*w+x2) * 5 + d2] = 1; dsf_merge(equivalence, y*w+x, y2*w+x2); done_something = true; todo_add(todo, y2*w+x2); } else if (!(o & d)) { /* This edge is closed in all orientations. */ #ifdef SOLVER_DIAGNOSTICS printf("marking edge %d,%d:%d closed\n", x, y, d); #endif edgestate[(y*w+x) * 5 + d] = 2; edgestate[(y2*w+x2) * 5 + d2] = 2; done_something = true; todo_add(todo, y2*w+x2); } } } /* * Now check the dead-end markers and see if any of * them has lowered from the real ones. */ for (d = 1; d <= 8; d += d) { int x2, y2, d2; OFFSETWH(x2, y2, x, y, d, w, h); d2 = F(d); if (deadendmax[d] > 0 && deadends[(y2*w+x2) * 5 + d2] > deadendmax[d]) { #ifdef SOLVER_DIAGNOSTICS printf("setting dead end value %d,%d:%d to %d\n", x2, y2, d2, deadendmax[d]); #endif deadends[(y2*w+x2) * 5 + d2] = deadendmax[d]; done_something = true; todo_add(todo, y2*w+x2); } } } } /* * Mark all completely determined tiles as locked. */ j = +1; for (i = 0; i < w*h; i++) { if (tilestate[i * 4 + 1] == 255) { assert(tilestate[i * 4 + 0] != 255); tiles[i] = tilestate[i * 4] | LOCKED; } else { tiles[i] &= ~LOCKED; j = 0; } } /* * Free up working space. */ todo_free(todo); sfree(tilestate); sfree(edgestate); sfree(deadends); sfree(equivalence); return j; } /* ---------------------------------------------------------------------- * Randomly select a new game description. */ /* * Function to randomly perturb an ambiguous section in a grid, to * attempt to ensure unique solvability. */ static void perturb(int w, int h, unsigned char *tiles, bool wrapping, random_state *rs, int startx, int starty, int startd) { struct xyd *perimeter, *perim2, *loop[2], looppos[2]; int nperim, perimsize, nloop[2], loopsize[2]; int x, y, d, i; /* * We know that the tile at (startx,starty) is part of an * ambiguous section, and we also know that its neighbour in * direction startd is fully specified. We begin by tracing all * the way round the ambiguous area. */ nperim = perimsize = 0; perimeter = NULL; x = startx; y = starty; d = startd; #ifdef PERTURB_DIAGNOSTICS printf("perturb %d,%d:%d\n", x, y, d); #endif do { int x2, y2, d2; if (nperim >= perimsize) { perimsize = perimsize * 3 / 2 + 32; perimeter = sresize(perimeter, perimsize, struct xyd); } perimeter[nperim].x = x; perimeter[nperim].y = y; perimeter[nperim].direction = d; nperim++; #ifdef PERTURB_DIAGNOSTICS printf("perimeter: %d,%d:%d\n", x, y, d); #endif /* * First, see if we can simply turn left from where we are * and find another locked square. */ d2 = A(d); OFFSETWH(x2, y2, x, y, d2, w, h); if ((!wrapping && (abs(x2-x) > 1 || abs(y2-y) > 1)) || (tiles[y2*w+x2] & LOCKED)) { d = d2; } else { /* * Failing that, step left into the new square and look * in front of us. */ x = x2; y = y2; OFFSETWH(x2, y2, x, y, d, w, h); if ((wrapping || (abs(x2-x) <= 1 && abs(y2-y) <= 1)) && !(tiles[y2*w+x2] & LOCKED)) { /* * And failing _that_, we're going to have to step * forward into _that_ square and look right at the * same locked square as we started with. */ x = x2; y = y2; d = C(d); } } } while (x != startx || y != starty || d != startd); /* * Our technique for perturbing this ambiguous area is to * search round its edge for a join we can make: that is, an * edge on the perimeter which is (a) not currently connected, * and (b) connecting it would not yield a full cross on either * side. Then we make that join, search round the network to * find the loop thus constructed, and sever the loop at a * randomly selected other point. */ perim2 = snewn(nperim, struct xyd); memcpy(perim2, perimeter, nperim * sizeof(struct xyd)); /* Shuffle the perimeter, so as to search it without directional bias. */ shuffle(perim2, nperim, sizeof(*perim2), rs); for (i = 0; i < nperim; i++) { int x2, y2; x = perim2[i].x; y = perim2[i].y; d = perim2[i].direction; OFFSETWH(x2, y2, x, y, d, w, h); if (!wrapping && (abs(x2-x) > 1 || abs(y2-y) > 1)) continue; /* can't link across non-wrapping border */ if (tiles[y*w+x] & d) continue; /* already linked in this direction! */ if (((tiles[y*w+x] | d) & 15) == 15) continue; /* can't turn this tile into a cross */ if (((tiles[y2*w+x2] | F(d)) & 15) == 15) continue; /* can't turn other tile into a cross */ /* * We've found the point at which we're going to make a new * link. */ #ifdef PERTURB_DIAGNOSTICS printf("linking %d,%d:%d\n", x, y, d); #endif tiles[y*w+x] |= d; tiles[y2*w+x2] |= F(d); break; } sfree(perim2); if (i == nperim) { sfree(perimeter); return; /* nothing we can do! */ } /* * Now we've constructed a new link, we need to find the entire * loop of which it is a part. * * In principle, this involves doing a complete search round * the network. However, I anticipate that in the vast majority * of cases the loop will be quite small, so what I'm going to * do is make _two_ searches round the network in parallel, one * keeping its metaphorical hand on the left-hand wall while * the other keeps its hand on the right. As soon as one of * them gets back to its starting point, I abandon the other. */ for (i = 0; i < 2; i++) { loopsize[i] = nloop[i] = 0; loop[i] = NULL; looppos[i].x = x; looppos[i].y = y; looppos[i].direction = d; } while (1) { for (i = 0; i < 2; i++) { int x2, y2, j; x = looppos[i].x; y = looppos[i].y; d = looppos[i].direction; OFFSETWH(x2, y2, x, y, d, w, h); /* * Add this path segment to the loop, unless it exactly * reverses the previous one on the loop in which case * we take it away again. */ #ifdef PERTURB_DIAGNOSTICS printf("looppos[%d] = %d,%d:%d\n", i, x, y, d); #endif if (nloop[i] > 0 && loop[i][nloop[i]-1].x == x2 && loop[i][nloop[i]-1].y == y2 && loop[i][nloop[i]-1].direction == F(d)) { #ifdef PERTURB_DIAGNOSTICS printf("removing path segment %d,%d:%d from loop[%d]\n", x2, y2, F(d), i); #endif nloop[i]--; } else { if (nloop[i] >= loopsize[i]) { loopsize[i] = loopsize[i] * 3 / 2 + 32; loop[i] = sresize(loop[i], loopsize[i], struct xyd); } #ifdef PERTURB_DIAGNOSTICS printf("adding path segment %d,%d:%d to loop[%d]\n", x, y, d, i); #endif loop[i][nloop[i]++] = looppos[i]; } #ifdef PERTURB_DIAGNOSTICS printf("tile at new location is %x\n", tiles[y2*w+x2] & 0xF); #endif d = F(d); for (j = 0; j < 4; j++) { if (i == 0) d = A(d); else d = C(d); #ifdef PERTURB_DIAGNOSTICS printf("trying dir %d\n", d); #endif if (tiles[y2*w+x2] & d) { looppos[i].x = x2; looppos[i].y = y2; looppos[i].direction = d; break; } } assert(j < 4); assert(nloop[i] > 0); if (looppos[i].x == loop[i][0].x && looppos[i].y == loop[i][0].y && looppos[i].direction == loop[i][0].direction) { #ifdef PERTURB_DIAGNOSTICS printf("loop %d finished tracking\n", i); #endif /* * Having found our loop, we now sever it at a * randomly chosen point - absolutely any will do - * which is not the one we joined it at to begin * with. Conveniently, the one we joined it at is * loop[i][0], so we just avoid that one. */ j = random_upto(rs, nloop[i]-1) + 1; x = loop[i][j].x; y = loop[i][j].y; d = loop[i][j].direction; OFFSETWH(x2, y2, x, y, d, w, h); tiles[y*w+x] &= ~d; tiles[y2*w+x2] &= ~F(d); break; } } if (i < 2) break; } sfree(loop[0]); sfree(loop[1]); /* * Finally, we must mark the entire disputed section as locked, * to prevent the perturb function being called on it multiple * times. * * To do this, we _sort_ the perimeter of the area. The * existing xyd_cmp function will arrange things into columns * for us, in such a way that each column has the edges in * vertical order. Then we can work down each column and fill * in all the squares between an up edge and a down edge. */ qsort(perimeter, nperim, sizeof(struct xyd), xyd_cmp); x = y = -1; for (i = 0; i <= nperim; i++) { if (i == nperim || perimeter[i].x > x) { /* * Fill in everything from the last Up edge to the * bottom of the grid, if necessary. */ if (x != -1) { while (y < h) { #ifdef PERTURB_DIAGNOSTICS printf("resolved: locking tile %d,%d\n", x, y); #endif tiles[y * w + x] |= LOCKED; y++; } x = y = -1; } if (i == nperim) break; x = perimeter[i].x; y = 0; } if (perimeter[i].direction == U) { x = perimeter[i].x; y = perimeter[i].y; } else if (perimeter[i].direction == D) { /* * Fill in everything from the last Up edge to here. */ assert(x == perimeter[i].x && y <= perimeter[i].y); while (y <= perimeter[i].y) { #ifdef PERTURB_DIAGNOSTICS printf("resolved: locking tile %d,%d\n", x, y); #endif tiles[y * w + x] |= LOCKED; y++; } x = y = -1; } } sfree(perimeter); } static int *compute_loops_inner(int w, int h, bool wrapping, const unsigned char *tiles, const unsigned char *barriers); static char *new_game_desc(const game_params *params, random_state *rs, char **aux, bool interactive) { tree234 *possibilities, *barriertree; int w, h, x, y, cx, cy, nbarriers; unsigned char *tiles, *barriers; char *desc, *p; w = params->width; h = params->height; cx = w / 2; cy = h / 2; tiles = snewn(w * h, unsigned char); barriers = snewn(w * h, unsigned char); begin_generation: memset(tiles, 0, w * h); memset(barriers, 0, w * h); /* * Construct the unshuffled grid. * * To do this, we simply start at the centre point, repeatedly * choose a random possibility out of the available ways to * extend a used square into an unused one, and do it. After * extending the third line out of a square, we remove the * fourth from the possibilities list to avoid any full-cross * squares (which would make the game too easy because they * only have one orientation). * * The slightly worrying thing is the avoidance of full-cross * squares. Can this cause our unsophisticated construction * algorithm to paint itself into a corner, by getting into a * situation where there are some unreached squares and the * only way to reach any of them is to extend a T-piece into a * full cross? * * Answer: no it can't, and here's a proof. * * Any contiguous group of such unreachable squares must be * surrounded on _all_ sides by T-pieces pointing away from the * group. (If not, then there is a square which can be extended * into one of the `unreachable' ones, and so it wasn't * unreachable after all.) In particular, this implies that * each contiguous group of unreachable squares must be * rectangular in shape (any deviation from that yields a * non-T-piece next to an `unreachable' square). * * So we have a rectangle of unreachable squares, with T-pieces * forming a solid border around the rectangle. The corners of * that border must be connected (since every tile connects all * the lines arriving in it), and therefore the border must * form a closed loop around the rectangle. * * But this can't have happened in the first place, since we * _know_ we've avoided creating closed loops! Hence, no such * situation can ever arise, and the naive grid construction * algorithm will guaranteeably result in a complete grid * containing no unreached squares, no full crosses _and_ no * closed loops. [] */ possibilities = newtree234(xyd_cmp_nc); if (cx+1 < w) add234(possibilities, new_xyd(cx, cy, R)); if (cy-1 >= 0) add234(possibilities, new_xyd(cx, cy, U)); if (cx-1 >= 0) add234(possibilities, new_xyd(cx, cy, L)); if (cy+1 < h) add234(possibilities, new_xyd(cx, cy, D)); while (count234(possibilities) > 0) { int i; struct xyd *xyd; int x1, y1, d1, x2, y2, d2, d; /* * Extract a randomly chosen possibility from the list. */ i = random_upto(rs, count234(possibilities)); xyd = delpos234(possibilities, i); x1 = xyd->x; y1 = xyd->y; d1 = xyd->direction; sfree(xyd); OFFSET(x2, y2, x1, y1, d1, params); d2 = F(d1); #ifdef GENERATION_DIAGNOSTICS printf("picked (%d,%d,%c) <-> (%d,%d,%c)\n", x1, y1, "0RU3L567D9abcdef"[d1], x2, y2, "0RU3L567D9abcdef"[d2]); #endif /* * Make the connection. (We should be moving to an as yet * unused tile.) */ index(params, tiles, x1, y1) |= d1; assert(index(params, tiles, x2, y2) == 0); index(params, tiles, x2, y2) |= d2; /* * If we have created a T-piece, remove its last * possibility. */ if (COUNT(index(params, tiles, x1, y1)) == 3) { struct xyd xyd1, *xydp; xyd1.x = x1; xyd1.y = y1; xyd1.direction = 0x0F ^ index(params, tiles, x1, y1); xydp = find234(possibilities, &xyd1, NULL); if (xydp) { #ifdef GENERATION_DIAGNOSTICS printf("T-piece; removing (%d,%d,%c)\n", xydp->x, xydp->y, "0RU3L567D9abcdef"[xydp->direction]); #endif del234(possibilities, xydp); sfree(xydp); } } /* * Remove all other possibilities that were pointing at the * tile we've just moved into. */ for (d = 1; d < 0x10; d <<= 1) { int x3, y3, d3; struct xyd xyd1, *xydp; OFFSET(x3, y3, x2, y2, d, params); d3 = F(d); xyd1.x = x3; xyd1.y = y3; xyd1.direction = d3; xydp = find234(possibilities, &xyd1, NULL); if (xydp) { #ifdef GENERATION_DIAGNOSTICS printf("Loop avoidance; removing (%d,%d,%c)\n", xydp->x, xydp->y, "0RU3L567D9abcdef"[xydp->direction]); #endif del234(possibilities, xydp); sfree(xydp); } } /* * Add new possibilities to the list for moving _out_ of * the tile we have just moved into. */ for (d = 1; d < 0x10; d <<= 1) { int x3, y3; if (d == d2) continue; /* we've got this one already */ if (!params->wrapping) { if (d == U && y2 == 0) continue; if (d == D && y2 == h-1) continue; if (d == L && x2 == 0) continue; if (d == R && x2 == w-1) continue; } OFFSET(x3, y3, x2, y2, d, params); if (index(params, tiles, x3, y3)) continue; /* this would create a loop */ #ifdef GENERATION_DIAGNOSTICS printf("New frontier; adding (%d,%d,%c)\n", x2, y2, "0RU3L567D9abcdef"[d]); #endif add234(possibilities, new_xyd(x2, y2, d)); } } /* Having done that, we should have no possibilities remaining. */ assert(count234(possibilities) == 0); freetree234(possibilities); if (params->unique) { int prevn = -1; /* * Run the solver to check unique solubility. */ while (net_solver(w, h, tiles, NULL, params->wrapping) != 1) { int n = 0; /* * We expect (in most cases) that most of the grid will * be uniquely specified already, and the remaining * ambiguous sections will be small and separate. So * our strategy is to find each individual such * section, and perform a perturbation on the network * in that area. */ for (y = 0; y < h; y++) for (x = 0; x < w; x++) { if (x+1 < w && ((tiles[y*w+x] ^ tiles[y*w+x+1]) & LOCKED)) { n++; if (tiles[y*w+x] & LOCKED) perturb(w, h, tiles, params->wrapping, rs, x+1, y, L); else perturb(w, h, tiles, params->wrapping, rs, x, y, R); } if (y+1 < h && ((tiles[y*w+x] ^ tiles[(y+1)*w+x]) & LOCKED)) { n++; if (tiles[y*w+x] & LOCKED) perturb(w, h, tiles, params->wrapping, rs, x, y+1, U); else perturb(w, h, tiles, params->wrapping, rs, x, y, D); } } /* * Now n counts the number of ambiguous sections we * have fiddled with. If we haven't managed to decrease * it from the last time we ran the solver, give up and * regenerate the entire grid. */ if (prevn != -1 && prevn <= n) goto begin_generation; /* (sorry) */ prevn = n; } /* * The solver will have left a lot of LOCKED bits lying * around in the tiles array. Remove them. */ for (x = 0; x < w*h; x++) tiles[x] &= ~LOCKED; } /* * Now compute a list of the possible barrier locations. */ barriertree = newtree234(xyd_cmp_nc); for (y = 0; y < h; y++) { for (x = 0; x < w; x++) { if (!(index(params, tiles, x, y) & R) && (params->wrapping || x < w-1)) add234(barriertree, new_xyd(x, y, R)); if (!(index(params, tiles, x, y) & D) && (params->wrapping || y < h-1)) add234(barriertree, new_xyd(x, y, D)); } } /* * Save the unshuffled grid in aux. */ { char *solution; int i; solution = snewn(w * h + 1, char); for (i = 0; i < w * h; i++) solution[i] = "0123456789abcdef"[tiles[i] & 0xF]; solution[w*h] = '\0'; *aux = solution; } /* * Now shuffle the grid. * * In order to avoid accidentally generating an already-solved * grid, we will reshuffle as necessary to ensure that at least * one edge has a mismatched connection. * * This can always be done, since validate_params() enforces a * grid area of at least 2 and our generator never creates * either type of rotationally invariant tile (cross and * blank). Hence there must be at least one edge separating * distinct tiles, and it must be possible to find orientations * of those tiles such that one tile is trying to connect * through that edge and the other is not. * * (We could be more subtle, and allow the shuffle to generate * a grid in which all tiles match up locally and the only * criterion preventing the grid from being already solved is * connectedness. However, that would take more effort, and * it's easier to simply make sure every grid is _obviously_ * not solved.) * * We also require that our shuffle produces no loops in the * initial grid state, because it's a bit rude to light up a 'HEY, * YOU DID SOMETHING WRONG!' indicator when the user hasn't even * had a chance to do _anything_ yet. This also is possible just * by retrying the whole shuffle on failure, because it's clear * that at least one non-solved shuffle with no loops must exist. * (Proof: take the _solved_ state of the puzzle, and rotate one * endpoint.) */ while (1) { int mismatches, prev_loopsquares, this_loopsquares, i; int *loops; shuffle: for (y = 0; y < h; y++) { for (x = 0; x < w; x++) { int orig = index(params, tiles, x, y); int rot = random_upto(rs, 4); index(params, tiles, x, y) = ROT(orig, rot); } } /* * Check for loops, and try to fix them by reshuffling just * the squares involved. */ prev_loopsquares = w*h+1; while (1) { loops = compute_loops_inner(w, h, params->wrapping, tiles, NULL); this_loopsquares = 0; for (i = 0; i < w*h; i++) { if (loops[i]) { int orig = tiles[i]; int rot = random_upto(rs, 4); tiles[i] = ROT(orig, rot); this_loopsquares++; } } sfree(loops); if (this_loopsquares > prev_loopsquares) { /* * We're increasing rather than reducing the number of * loops. Give up and go back to the full shuffle. */ goto shuffle; } if (this_loopsquares == 0) break; prev_loopsquares = this_loopsquares; } mismatches = 0; /* * I can't even be bothered to check for mismatches across * a wrapping edge, so I'm just going to enforce that there * must be a mismatch across a non-wrapping edge, which is * still always possible. */ for (y = 0; y < h; y++) for (x = 0; x < w; x++) { if (x+1 < w && ((ROT(index(params, tiles, x, y), 2) ^ index(params, tiles, x+1, y)) & L)) mismatches++; if (y+1 < h && ((ROT(index(params, tiles, x, y), 2) ^ index(params, tiles, x, y+1)) & U)) mismatches++; } if (mismatches == 0) continue; /* OK. */ break; } /* * And now choose barrier locations. (We carefully do this * _after_ shuffling, so that changing the barrier rate in the * params while keeping the random seed the same will give the * same shuffled grid and _only_ change the barrier locations. * Also the way we choose barrier locations, by repeatedly * choosing one possibility from the list until we have enough, * is designed to ensure that raising the barrier rate while * keeping the seed the same will provide a superset of the * previous barrier set - i.e. if you ask for 10 barriers, and * then decide that's still too hard and ask for 20, you'll get * the original 10 plus 10 more, rather than getting 20 new * ones and the chance of remembering your first 10.) */ nbarriers = (int)(params->barrier_probability * count234(barriertree)); assert(nbarriers >= 0 && nbarriers <= count234(barriertree)); while (nbarriers > 0) { int i; struct xyd *xyd; int x1, y1, d1, x2, y2, d2; /* * Extract a randomly chosen barrier from the list. */ i = random_upto(rs, count234(barriertree)); xyd = delpos234(barriertree, i); assert(xyd != NULL); x1 = xyd->x; y1 = xyd->y; d1 = xyd->direction; sfree(xyd); OFFSET(x2, y2, x1, y1, d1, params); d2 = F(d1); index(params, barriers, x1, y1) |= d1; index(params, barriers, x2, y2) |= d2; nbarriers--; } /* * Clean up the rest of the barrier list. */ { struct xyd *xyd; while ( (xyd = delpos234(barriertree, 0)) != NULL) sfree(xyd); freetree234(barriertree); } /* * Finally, encode the grid into a string game description. * * My syntax is extremely simple: each square is encoded as a * hex digit in which bit 0 means a connection on the right, * bit 1 means up, bit 2 left and bit 3 down. (i.e. the same * encoding as used internally). Each digit is followed by * optional barrier indicators: `v' means a vertical barrier to * the right of it, and `h' means a horizontal barrier below * it. */ desc = snewn(w * h * 3 + 1, char); p = desc; for (y = 0; y < h; y++) { for (x = 0; x < w; x++) { *p++ = "0123456789abcdef"[index(params, tiles, x, y)]; if ((params->wrapping || x < w-1) && (index(params, barriers, x, y) & R)) *p++ = 'v'; if ((params->wrapping || y < h-1) && (index(params, barriers, x, y) & D)) *p++ = 'h'; } } assert(p - desc <= w*h*3); *p = '\0'; sfree(tiles); sfree(barriers); return desc; } static const char *validate_desc(const game_params *params, const char *desc) { int w = params->width, h = params->height; int i; for (i = 0; i < w*h; i++) { if (*desc >= '0' && *desc <= '9') /* OK */; else if (*desc >= 'a' && *desc <= 'f') /* OK */; else if (*desc >= 'A' && *desc <= 'F') /* OK */; else if (!*desc) return "Game description shorter than expected"; else return "Game description contained unexpected character"; desc++; while (*desc == 'h' || *desc == 'v') desc++; } if (*desc) return "Game description longer than expected"; return NULL; } /* ---------------------------------------------------------------------- * Construct an initial game state, given a description and parameters. */ static game_state *new_game(midend *me, const game_params *params, const char *desc) { game_state *state; int w, h, x, y; assert(params->width > 0 && params->height > 0); assert(params->width > 1 || params->height > 1); /* * Create a blank game state. */ state = snew(game_state); w = state->width = params->width; h = state->height = params->height; state->wrapping = params->wrapping; state->imm = snew(game_immutable_state); state->imm->refcount = 1; state->last_rotate_dir = state->last_rotate_x = state->last_rotate_y = 0; state->completed = state->used_solve = false; state->tiles = snewn(state->width * state->height, unsigned char); memset(state->tiles, 0, state->width * state->height); state->imm->barriers = snewn(state->width * state->height, unsigned char); memset(state->imm->barriers, 0, state->width * state->height); /* * Parse the game description into the grid. */ for (y = 0; y < h; y++) { for (x = 0; x < w; x++) { if (*desc >= '0' && *desc <= '9') tile(state, x, y) = *desc - '0'; else if (*desc >= 'a' && *desc <= 'f') tile(state, x, y) = *desc - 'a' + 10; else if (*desc >= 'A' && *desc <= 'F') tile(state, x, y) = *desc - 'A' + 10; if (*desc) desc++; while (*desc == 'h' || *desc == 'v') { int x2, y2, d1, d2; if (*desc == 'v') d1 = R; else d1 = D; OFFSET(x2, y2, x, y, d1, state); d2 = F(d1); barrier(state, x, y) |= d1; barrier(state, x2, y2) |= d2; desc++; } } } /* * Set up border barriers if this is a non-wrapping game. */ if (!state->wrapping) { for (x = 0; x < state->width; x++) { barrier(state, x, 0) |= U; barrier(state, x, state->height-1) |= D; } for (y = 0; y < state->height; y++) { barrier(state, 0, y) |= L; barrier(state, state->width-1, y) |= R; } } else { /* * We check whether this is de-facto a non-wrapping game * despite the parameters, in case we were passed the * description of a non-wrapping game. This is so that we * can change some aspects of the UI behaviour. */ state->wrapping = false; for (x = 0; x < state->width; x++) if (!(barrier(state, x, 0) & U) || !(barrier(state, x, state->height-1) & D)) state->wrapping = true; for (y = 0; y < state->height; y++) if (!(barrier(state, 0, y) & L) || !(barrier(state, state->width-1, y) & R)) state->wrapping = true; } return state; } static game_state *dup_game(const game_state *state) { game_state *ret; ret = snew(game_state); ret->imm = state->imm; ret->imm->refcount++; ret->width = state->width; ret->height = state->height; ret->wrapping = state->wrapping; ret->completed = state->completed; ret->used_solve = state->used_solve; ret->last_rotate_dir = state->last_rotate_dir; ret->last_rotate_x = state->last_rotate_x; ret->last_rotate_y = state->last_rotate_y; ret->tiles = snewn(state->width * state->height, unsigned char); memcpy(ret->tiles, state->tiles, state->width * state->height); return ret; } static void free_game(game_state *state) { if (--state->imm->refcount == 0) { sfree(state->imm->barriers); sfree(state->imm); } sfree(state->tiles); sfree(state); } static char *solve_game(const game_state *state, const game_state *currstate, const char *aux, const char **error) { unsigned char *tiles; char *ret; int retlen, retsize; int i; tiles = snewn(state->width * state->height, unsigned char); if (!aux) { /* * Run the internal solver on the provided grid. This might * not yield a complete solution. */ int solver_result; memcpy(tiles, state->tiles, state->width * state->height); solver_result = net_solver(state->width, state->height, tiles, state->imm->barriers, state->wrapping); if (solver_result < 0) { *error = "No solution exists for this puzzle"; sfree(tiles); return NULL; } } else { for (i = 0; i < state->width * state->height; i++) { int c = aux[i]; if (c >= '0' && c <= '9') tiles[i] = c - '0'; else if (c >= 'a' && c <= 'f') tiles[i] = c - 'a' + 10; else if (c >= 'A' && c <= 'F') tiles[i] = c - 'A' + 10; tiles[i] |= LOCKED; } } /* * Now construct a string which can be passed to execute_move() * to transform the current grid into the solved one. */ retsize = 256; ret = snewn(retsize, char); retlen = 0; ret[retlen++] = 'S'; for (i = 0; i < state->width * state->height; i++) { int from = currstate->tiles[i], to = tiles[i]; int ft = from & (R|L|U|D), tt = to & (R|L|U|D); int x = i % state->width, y = i / state->width; int chr = '\0'; char buf[80], *p = buf; if (from == to) continue; /* nothing needs doing at all */ /* * To transform this tile into the desired tile: first * unlock the tile if it's locked, then rotate it if * necessary, then lock it if necessary. */ if (from & LOCKED) p += sprintf(p, ";L%d,%d", x, y); if (tt == A(ft)) chr = 'A'; else if (tt == C(ft)) chr = 'C'; else if (tt == F(ft)) chr = 'F'; else { assert(tt == ft); chr = '\0'; } if (chr) p += sprintf(p, ";%c%d,%d", chr, x, y); if (to & LOCKED) p += sprintf(p, ";L%d,%d", x, y); if (p > buf) { if (retlen + (p - buf) >= retsize) { retsize = retlen + (p - buf) + 512; ret = sresize(ret, retsize, char); } memcpy(ret+retlen, buf, p - buf); retlen += p - buf; } } assert(retlen < retsize); ret[retlen] = '\0'; ret = sresize(ret, retlen+1, char); sfree(tiles); return ret; } /* ---------------------------------------------------------------------- * Utility routine. */ /* * Compute which squares are reachable from the centre square, as a * quick visual aid to determining how close the game is to * completion. This is also a simple way to tell if the game _is_ * completed - just call this function and see whether every square * is marked active. */ static unsigned char *compute_active(const game_state *state, int cx, int cy) { unsigned char *active; tree234 *todo; struct xyd *xyd; active = snewn(state->width * state->height, unsigned char); memset(active, 0, state->width * state->height); /* * We only store (x,y) pairs in todo, but it's easier to reuse * xyd_cmp and just store direction 0 every time. */ todo = newtree234(xyd_cmp_nc); index(state, active, cx, cy) = ACTIVE; add234(todo, new_xyd(cx, cy, 0)); while ( (xyd = delpos234(todo, 0)) != NULL) { int x1, y1, d1, x2, y2, d2; x1 = xyd->x; y1 = xyd->y; sfree(xyd); for (d1 = 1; d1 < 0x10; d1 <<= 1) { OFFSET(x2, y2, x1, y1, d1, state); d2 = F(d1); /* * If the next tile in this direction is connected to * us, and there isn't a barrier in the way, and it * isn't already marked active, then mark it active and * add it to the to-examine list. */ if ((tile(state, x1, y1) & d1) && (tile(state, x2, y2) & d2) && !(barrier(state, x1, y1) & d1) && !index(state, active, x2, y2)) { index(state, active, x2, y2) = ACTIVE; add234(todo, new_xyd(x2, y2, 0)); } } } /* Now we expect the todo list to have shrunk to zero size. */ assert(count234(todo) == 0); freetree234(todo); return active; } struct net_neighbour_ctx { int w, h; const unsigned char *tiles, *barriers; int i, n, neighbours[4]; }; static int net_neighbour(int vertex, void *vctx) { struct net_neighbour_ctx *ctx = (struct net_neighbour_ctx *)vctx; if (vertex >= 0) { int x = vertex % ctx->w, y = vertex / ctx->w; int tile, dir, x1, y1, v1; ctx->i = ctx->n = 0; tile = ctx->tiles[vertex]; if (ctx->barriers) tile &= ~ctx->barriers[vertex]; for (dir = 1; dir < 0x10; dir <<= 1) { if (!(tile & dir)) continue; OFFSETWH(x1, y1, x, y, dir, ctx->w, ctx->h); v1 = y1 * ctx->w + x1; if (ctx->tiles[v1] & F(dir)) ctx->neighbours[ctx->n++] = v1; } } if (ctx->i < ctx->n) return ctx->neighbours[ctx->i++]; else return -1; } static int *compute_loops_inner(int w, int h, bool wrapping, const unsigned char *tiles, const unsigned char *barriers) { struct net_neighbour_ctx ctx; struct findloopstate *fls; int *loops; int x, y; fls = findloop_new_state(w*h); ctx.w = w; ctx.h = h; ctx.tiles = tiles; ctx.barriers = barriers; findloop_run(fls, w*h, net_neighbour, &ctx); loops = snewn(w*h, int); for (y = 0; y < h; y++) { for (x = 0; x < w; x++) { int x1, y1, dir; int flags = 0; for (dir = 1; dir < 0x10; dir <<= 1) { if ((tiles[y*w+x] & dir) && !(barriers && (barriers[y*w+x] & dir))) { OFFSETWH(x1, y1, x, y, dir, w, h); if ((tiles[y1*w+x1] & F(dir)) && findloop_is_loop_edge(fls, y*w+x, y1*w+x1)) flags |= ERR(dir); } } loops[y*w+x] = flags; } } findloop_free_state(fls); return loops; } static int *compute_loops(const game_state *state) { return compute_loops_inner(state->width, state->height, state->wrapping, state->tiles, state->imm->barriers); } struct game_ui { int org_x, org_y; /* origin */ int cx, cy; /* source tile (game coordinates) */ int cur_x, cur_y; bool cur_visible; random_state *rs; /* used for jumbling */ #ifdef USE_DRAGGING int dragtilex, dragtiley, dragstartx, dragstarty; bool dragged; #endif }; static game_ui *new_ui(const game_state *state) { void *seed; int seedsize; game_ui *ui = snew(game_ui); ui->org_x = ui->org_y = 0; ui->cur_x = ui->cx = state->width / 2; ui->cur_y = ui->cy = state->height / 2; ui->cur_visible = false; get_random_seed(&seed, &seedsize); ui->rs = random_new(seed, seedsize); sfree(seed); return ui; } static void free_ui(game_ui *ui) { random_free(ui->rs); sfree(ui); } static char *encode_ui(const game_ui *ui) { char buf[120]; /* * We preserve the origin and centre-point coordinates over a * serialise. */ sprintf(buf, "O%d,%d;C%d,%d", ui->org_x, ui->org_y, ui->cx, ui->cy); return dupstr(buf); } static void decode_ui(game_ui *ui, const char *encoding) { sscanf(encoding, "O%d,%d;C%d,%d", &ui->org_x, &ui->org_y, &ui->cx, &ui->cy); } static void game_changed_state(game_ui *ui, const game_state *oldstate, const game_state *newstate) { } static const char *current_key_label(const game_ui *ui, const game_state *state, int button) { if (tile(state, ui->cur_x, ui->cur_y) & LOCKED) { if (button == CURSOR_SELECT2) return "Unlock"; } else { if (button == CURSOR_SELECT) return "Rotate"; if (button == CURSOR_SELECT2) return "Lock"; } return ""; } struct game_drawstate { int width, height; int tilesize; unsigned long *visible, *to_draw; }; /* ---------------------------------------------------------------------- * Process a move. */ static char *interpret_move(const game_state *state, game_ui *ui, const game_drawstate *ds, int x, int y, int button) { char *nullret; int tx = -1, ty = -1, dir = 0; bool shift = button & MOD_SHFT, ctrl = button & MOD_CTRL; enum { NONE, ROTATE_LEFT, ROTATE_180, ROTATE_RIGHT, TOGGLE_LOCK, JUMBLE, MOVE_ORIGIN, MOVE_SOURCE, MOVE_ORIGIN_AND_SOURCE, MOVE_CURSOR } action; button &= ~MOD_MASK; nullret = NULL; action = NONE; if (button == LEFT_BUTTON || button == MIDDLE_BUTTON || #ifdef USE_DRAGGING button == LEFT_DRAG || button == LEFT_RELEASE || button == RIGHT_DRAG || button == RIGHT_RELEASE || #endif button == RIGHT_BUTTON) { if (ui->cur_visible) { ui->cur_visible = false; nullret = UI_UPDATE; } /* * The button must have been clicked on a valid tile. */ x -= WINDOW_OFFSET + LINE_THICK; y -= WINDOW_OFFSET + LINE_THICK; if (x < 0 || y < 0) return nullret; tx = x / TILE_SIZE; ty = y / TILE_SIZE; if (tx >= state->width || ty >= state->height) return nullret; /* Transform from physical to game coords */ tx = (tx + ui->org_x) % state->width; ty = (ty + ui->org_y) % state->height; if (x % TILE_SIZE >= TILE_SIZE - LINE_THICK || y % TILE_SIZE >= TILE_SIZE - LINE_THICK) return nullret; #ifdef USE_DRAGGING if (button == MIDDLE_BUTTON #ifdef STYLUS_BASED || button == RIGHT_BUTTON /* with a stylus, `right-click' locks */ #endif ) { /* * Middle button never drags: it only toggles the lock. */ action = TOGGLE_LOCK; } else if (button == LEFT_BUTTON #ifndef STYLUS_BASED || button == RIGHT_BUTTON /* (see above) */ #endif ) { /* * Otherwise, we note down the start point for a drag. */ ui->dragtilex = tx; ui->dragtiley = ty; ui->dragstartx = x % TILE_SIZE; ui->dragstarty = y % TILE_SIZE; ui->dragged = false; return nullret; /* no actual action */ } else if (button == LEFT_DRAG #ifndef STYLUS_BASED || button == RIGHT_DRAG #endif ) { /* * Find the new drag point and see if it necessitates a * rotation. */ int x0,y0, xA,yA, xC,yC, xF,yF; int mx, my; int d0, dA, dC, dF, dmin; tx = ui->dragtilex; ty = ui->dragtiley; mx = x - (ui->dragtilex * TILE_SIZE); my = y - (ui->dragtiley * TILE_SIZE); x0 = ui->dragstartx; y0 = ui->dragstarty; xA = ui->dragstarty; yA = TILE_SIZE-1 - ui->dragstartx; xF = TILE_SIZE-1 - ui->dragstartx; yF = TILE_SIZE-1 - ui->dragstarty; xC = TILE_SIZE-1 - ui->dragstarty; yC = ui->dragstartx; d0 = (mx-x0)*(mx-x0) + (my-y0)*(my-y0); dA = (mx-xA)*(mx-xA) + (my-yA)*(my-yA); dF = (mx-xF)*(mx-xF) + (my-yF)*(my-yF); dC = (mx-xC)*(mx-xC) + (my-yC)*(my-yC); dmin = min(min(d0,dA),min(dF,dC)); if (d0 == dmin) { return nullret; } else if (dF == dmin) { action = ROTATE_180; ui->dragstartx = xF; ui->dragstarty = yF; ui->dragged = true; } else if (dA == dmin) { action = ROTATE_LEFT; ui->dragstartx = xA; ui->dragstarty = yA; ui->dragged = true; } else /* dC == dmin */ { action = ROTATE_RIGHT; ui->dragstartx = xC; ui->dragstarty = yC; ui->dragged = true; } } else if (button == LEFT_RELEASE #ifndef STYLUS_BASED || button == RIGHT_RELEASE #endif ) { if (!ui->dragged) { /* * There was a click but no perceptible drag: * revert to single-click behaviour. */ tx = ui->dragtilex; ty = ui->dragtiley; if (button == LEFT_RELEASE) action = ROTATE_LEFT; else action = ROTATE_RIGHT; } else return nullret; /* no action */ } #else /* USE_DRAGGING */ action = (button == LEFT_BUTTON ? ROTATE_LEFT : button == RIGHT_BUTTON ? ROTATE_RIGHT : TOGGLE_LOCK); #endif /* USE_DRAGGING */ } else if (IS_CURSOR_MOVE(button)) { switch (button) { case CURSOR_UP: dir = U; break; case CURSOR_DOWN: dir = D; break; case CURSOR_LEFT: dir = L; break; case CURSOR_RIGHT: dir = R; break; default: return nullret; } if (shift && ctrl) action = MOVE_ORIGIN_AND_SOURCE; else if (shift) action = MOVE_ORIGIN; else if (ctrl) action = MOVE_SOURCE; else action = MOVE_CURSOR; } else if (button == 'a' || button == 's' || button == 'd' || button == 'A' || button == 'S' || button == 'D' || button == 'f' || button == 'F' || IS_CURSOR_SELECT(button)) { tx = ui->cur_x; ty = ui->cur_y; if (button == 'a' || button == 'A' || button == CURSOR_SELECT) action = ROTATE_LEFT; else if (button == 's' || button == 'S' || button == CURSOR_SELECT2) action = TOGGLE_LOCK; else if (button == 'd' || button == 'D') action = ROTATE_RIGHT; else if (button == 'f' || button == 'F') action = ROTATE_180; ui->cur_visible = true; } else if (button == 'j' || button == 'J') { /* XXX should we have some mouse control for this? */ action = JUMBLE; } else return nullret; /* * The middle button locks or unlocks a tile. (A locked tile * cannot be turned, and is visually marked as being locked. * This is a convenience for the player, so that once they are * sure which way round a tile goes, they can lock it and thus * avoid forgetting later on that they'd already done that one; * and the locking also prevents them turning the tile by * accident. If they change their mind, another middle click * unlocks it.) */ if (action == TOGGLE_LOCK) { char buf[80]; sprintf(buf, "L%d,%d", tx, ty); return dupstr(buf); } else if (action == ROTATE_LEFT || action == ROTATE_RIGHT || action == ROTATE_180) { char buf[80]; /* * The left and right buttons have no effect if clicked on a * locked tile. */ if (tile(state, tx, ty) & LOCKED) return nullret; /* * Otherwise, turn the tile one way or the other. Left button * turns anticlockwise; right button turns clockwise. */ sprintf(buf, "%c%d,%d", (int)(action == ROTATE_LEFT ? 'A' : action == ROTATE_RIGHT ? 'C' : 'F'), tx, ty); return dupstr(buf); } else if (action == JUMBLE) { /* * Jumble all unlocked tiles to random orientations. */ int jx, jy, maxlen; char *ret, *p; /* * Maximum string length assumes no int can be converted to * decimal and take more than 11 digits! */ maxlen = state->width * state->height * 25 + 3; ret = snewn(maxlen, char); p = ret; *p++ = 'J'; for (jy = 0; jy < state->height; jy++) { for (jx = 0; jx < state->width; jx++) { if (!(tile(state, jx, jy) & LOCKED)) { int rot = random_upto(ui->rs, 4); if (rot) { p += sprintf(p, ";%c%d,%d", "AFC"[rot-1], jx, jy); } } } } *p++ = '\0'; assert(p - ret < maxlen); ret = sresize(ret, p - ret, char); return ret; } else if (action == MOVE_ORIGIN || action == MOVE_SOURCE || action == MOVE_ORIGIN_AND_SOURCE || action == MOVE_CURSOR) { assert(dir != 0); if (action == MOVE_ORIGIN || action == MOVE_ORIGIN_AND_SOURCE) { if (state->wrapping) { OFFSET(ui->org_x, ui->org_y, ui->org_x, ui->org_y, dir, state); } else return nullret; /* disallowed for non-wrapping grids */ } if (action == MOVE_SOURCE || action == MOVE_ORIGIN_AND_SOURCE) { OFFSET(ui->cx, ui->cy, ui->cx, ui->cy, dir, state); } if (action == MOVE_CURSOR) { OFFSET(ui->cur_x, ui->cur_y, ui->cur_x, ui->cur_y, dir, state); ui->cur_visible = true; } return UI_UPDATE; } else { return NULL; } } static game_state *execute_move(const game_state *from, const char *move) { game_state *ret; int tx = -1, ty = -1, n, orig; bool noanim; ret = dup_game(from); if (move[0] == 'J' || move[0] == 'S') { if (move[0] == 'S') ret->used_solve = true; move++; if (*move == ';') move++; noanim = true; } else noanim = false; ret->last_rotate_dir = 0; /* suppress animation */ ret->last_rotate_x = ret->last_rotate_y = 0; while (*move) { if ((move[0] == 'A' || move[0] == 'C' || move[0] == 'F' || move[0] == 'L') && sscanf(move+1, "%d,%d%n", &tx, &ty, &n) >= 2 && tx >= 0 && tx < from->width && ty >= 0 && ty < from->height) { orig = tile(ret, tx, ty); if (move[0] == 'A') { tile(ret, tx, ty) = A(orig); if (!noanim) ret->last_rotate_dir = +1; } else if (move[0] == 'F') { tile(ret, tx, ty) = F(orig); if (!noanim) ret->last_rotate_dir = +2; /* + for sake of argument */ } else if (move[0] == 'C') { tile(ret, tx, ty) = C(orig); if (!noanim) ret->last_rotate_dir = -1; } else { assert(move[0] == 'L'); tile(ret, tx, ty) ^= LOCKED; } move += 1 + n; if (*move == ';') move++; } else { free_game(ret); return NULL; } } if (!noanim) { if (tx == -1 || ty == -1) { free_game(ret); return NULL; } ret->last_rotate_x = tx; ret->last_rotate_y = ty; } /* * Check whether the game has been completed. * * For this purpose it doesn't matter where the source square is, * because we can start from anywhere (or, at least, any square * that's non-empty!), and correctly determine whether the game is * completed. */ { unsigned char *active; int pos; bool complete = true; for (pos = 0; pos < ret->width * ret->height; pos++) if (ret->tiles[pos] & 0xF) break; if (pos < ret->width * ret->height) { active = compute_active(ret, pos % ret->width, pos / ret->width); for (pos = 0; pos < ret->width * ret->height; pos++) if ((ret->tiles[pos] & 0xF) && !active[pos]) { complete = false; break; } sfree(active); } if (complete) ret->completed = true; } return ret; } /* ---------------------------------------------------------------------- * Routines for drawing the game position on the screen. */ static game_drawstate *game_new_drawstate(drawing *dr, const game_state *state) { game_drawstate *ds = snew(game_drawstate); int i, ncells; ds->width = state->width; ds->height = state->height; ncells = (state->width+2) * (state->height+2); ds->visible = snewn(ncells, unsigned long); ds->to_draw = snewn(ncells, unsigned long); ds->tilesize = 0; /* undecided yet */ for (i = 0; i < ncells; i++) ds->visible[i] = -1; return ds; } #define dsindex(ds, field, x, y) ((ds)->field[((y)+1)*((ds)->width+2)+((x)+1)]) #define visible(ds, x, y) dsindex(ds, visible, x, y) #define todraw(ds, x, y) dsindex(ds, to_draw, x, y) static void game_free_drawstate(drawing *dr, game_drawstate *ds) { sfree(ds->visible); sfree(ds->to_draw); sfree(ds); } static void game_compute_size(const game_params *params, int tilesize, int *x, int *y) { /* Ick: fake up `ds->tilesize' for macro expansion purposes */ struct { int tilesize; } ads, *ds = &ads; ads.tilesize = tilesize; *x = WINDOW_OFFSET * 2 + TILE_SIZE * params->width + LINE_THICK; *y = WINDOW_OFFSET * 2 + TILE_SIZE * params->height + LINE_THICK; } static void game_set_size(drawing *dr, game_drawstate *ds, const game_params *params, int tilesize) { ds->tilesize = tilesize; } static float *game_colours(frontend *fe, int *ncolours) { float *ret; ret = snewn(NCOLOURS * 3, float); *ncolours = NCOLOURS; /* * Basic background colour is whatever the front end thinks is * a sensible default. */ frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]); /* * Wires are black. */ ret[COL_WIRE * 3 + 0] = 0.0F; ret[COL_WIRE * 3 + 1] = 0.0F; ret[COL_WIRE * 3 + 2] = 0.0F; /* * Powered wires and powered endpoints are cyan. */ ret[COL_POWERED * 3 + 0] = 0.0F; ret[COL_POWERED * 3 + 1] = 1.0F; ret[COL_POWERED * 3 + 2] = 1.0F; /* * Barriers are red. */ ret[COL_BARRIER * 3 + 0] = 1.0F; ret[COL_BARRIER * 3 + 1] = 0.0F; ret[COL_BARRIER * 3 + 2] = 0.0F; /* * Highlighted errors are red as well. */ ret[COL_ERR * 3 + 0] = 1.0F; ret[COL_ERR * 3 + 1] = 0.0F; ret[COL_ERR * 3 + 2] = 0.0F; /* * Unpowered endpoints are blue. */ ret[COL_ENDPOINT * 3 + 0] = 0.0F; ret[COL_ENDPOINT * 3 + 1] = 0.0F; ret[COL_ENDPOINT * 3 + 2] = 1.0F; /* * Tile borders are a darker grey than the background. */ ret[COL_BORDER * 3 + 0] = 0.5F * ret[COL_BACKGROUND * 3 + 0]; ret[COL_BORDER * 3 + 1] = 0.5F * ret[COL_BACKGROUND * 3 + 1]; ret[COL_BORDER * 3 + 2] = 0.5F * ret[COL_BACKGROUND * 3 + 2]; /* * Locked tiles are a grey in between those two. */ ret[COL_LOCKED * 3 + 0] = 0.75F * ret[COL_BACKGROUND * 3 + 0]; ret[COL_LOCKED * 3 + 1] = 0.75F * ret[COL_BACKGROUND * 3 + 1]; ret[COL_LOCKED * 3 + 2] = 0.75F * ret[COL_BACKGROUND * 3 + 2]; return ret; } static void rotated_coords(float *ox, float *oy, const float matrix[4], float cx, float cy, float ix, float iy) { *ox = matrix[0] * ix + matrix[2] * iy + cx; *oy = matrix[1] * ix + matrix[3] * iy + cy; } /* Flags describing the visible features of a tile. */ #define TILE_BARRIER_SHIFT 0 /* 4 bits: R U L D */ #define TILE_BARRIER_CORNER_SHIFT 4 /* 4 bits: RU UL LD DR */ #define TILE_KEYBOARD_CURSOR (1<<8) /* 1 bit if cursor is here */ #define TILE_WIRE_SHIFT 9 /* 8 bits: RR UU LL DD * Each pair: 0=no wire, 1=unpowered, * 2=powered, 3=error highlight */ #define TILE_ENDPOINT_SHIFT 17 /* 2 bits: 0=no endpoint, 1=unpowered, * 2=powered, 3=power-source square */ #define TILE_WIRE_ON_EDGE_SHIFT 19 /* 8 bits: RR UU LL DD, * same encoding as TILE_WIRE_SHIFT */ #define TILE_ROTATING (1UL<<27) /* 1 bit if tile is rotating */ #define TILE_LOCKED (1UL<<28) /* 1 bit if tile is locked */ static void draw_wires(drawing *dr, int cx, int cy, int radius, unsigned long tile, int bitmap, int colour, int halfwidth, const float matrix[4]) { float fpoints[12*2]; int points[12*2]; int npoints, d, dsh, i; bool any_wire_this_colour = false; float xf, yf; npoints = 0; for (d = 1, dsh = 0; d < 16; d *= 2, dsh++) { int wiretype = (tile >> (TILE_WIRE_SHIFT + 2*dsh)) & 3; fpoints[2*npoints+0] = halfwidth * (X(d) + X(C(d))); fpoints[2*npoints+1] = halfwidth * (Y(d) + Y(C(d))); npoints++; if (bitmap & (1 << wiretype)) { fpoints[2*npoints+0] = radius * X(d) + halfwidth * X(C(d)); fpoints[2*npoints+1] = radius * Y(d) + halfwidth * Y(C(d)); npoints++; fpoints[2*npoints+0] = radius * X(d) + halfwidth * X(A(d)); fpoints[2*npoints+1] = radius * Y(d) + halfwidth * Y(A(d)); npoints++; any_wire_this_colour = true; } } if (!any_wire_this_colour) return; for (i = 0; i < npoints; i++) { rotated_coords(&xf, &yf, matrix, cx, cy, fpoints[2*i], fpoints[2*i+1]); points[2*i] = 0.5F + xf; points[2*i+1] = 0.5F + yf; } draw_polygon(dr, points, npoints, colour, colour); } static void draw_tile(drawing *dr, game_drawstate *ds, int x, int y, unsigned long tile, float angle) { int tx, ty; int clipx, clipy, clipX, clipY, clipw, cliph; int border_br = LINE_THICK/2, border_tl = LINE_THICK - border_br; int barrier_outline_thick = (LINE_THICK+1)/2; int bg, d, dsh, pass; int cx, cy, radius; float matrix[4]; tx = WINDOW_OFFSET + TILE_SIZE * x + border_br; ty = WINDOW_OFFSET + TILE_SIZE * y + border_br; /* * Clip to the tile boundary, with adjustments if we're drawing * just outside the grid. */ clipx = tx; clipX = tx + TILE_SIZE; clipy = ty; clipY = ty + TILE_SIZE; if (x == -1) { clipx = clipX - border_br - barrier_outline_thick; } else if (x == ds->width) { clipX = clipx + border_tl + barrier_outline_thick; } if (y == -1) { clipy = clipY - border_br - barrier_outline_thick; } else if (y == ds->height) { clipY = clipy + border_tl + barrier_outline_thick; } clipw = clipX - clipx; cliph = clipY - clipy; clip(dr, clipx, clipy, clipw, cliph); /* * Clear the clip region. */ bg = (tile & TILE_LOCKED) ? COL_LOCKED : COL_BACKGROUND; draw_rect(dr, clipx, clipy, clipw, cliph, bg); /* * Draw the grid lines. */ { int gridl = (x == -1 ? tx+TILE_SIZE-border_br : tx); int gridr = (x == ds->width ? tx+border_tl : tx+TILE_SIZE); int gridu = (y == -1 ? ty+TILE_SIZE-border_br : ty); int gridd = (y == ds->height ? ty+border_tl : ty+TILE_SIZE); if (x >= 0) draw_rect(dr, tx, gridu, border_tl, gridd-gridu, COL_BORDER); if (y >= 0) draw_rect(dr, gridl, ty, gridr-gridl, border_tl, COL_BORDER); if (x < ds->width) draw_rect(dr, tx+TILE_SIZE-border_br, gridu, border_br, gridd-gridu, COL_BORDER); if (y < ds->height) draw_rect(dr, gridl, ty+TILE_SIZE-border_br, gridr-gridl, border_br, COL_BORDER); } /* * Draw the keyboard cursor. */ if (tile & TILE_KEYBOARD_CURSOR) { int cursorcol = (tile & TILE_LOCKED) ? COL_BACKGROUND : COL_LOCKED; int inset_outer = TILE_SIZE/8, inset_inner = inset_outer + LINE_THICK; draw_rect(dr, tx + inset_outer, ty + inset_outer, TILE_SIZE - 2*inset_outer, TILE_SIZE - 2*inset_outer, cursorcol); draw_rect(dr, tx + inset_inner, ty + inset_inner, TILE_SIZE - 2*inset_inner, TILE_SIZE - 2*inset_inner, bg); } radius = (TILE_SIZE+1)/2; cx = tx + radius; cy = ty + radius; radius++; /* * Draw protrusions into this cell's edges of wires in * neighbouring cells, as given by the TILE_WIRE_ON_EDGE_SHIFT * flags. We only draw each of these if there _isn't_ a wire of * our own that's going to overlap it, which means either the * corresponding TILE_WIRE_SHIFT flag is zero, or else the * TILE_ROTATING flag is set (so that our main wire won't be drawn * in quite that place anyway). */ for (d = 1, dsh = 0; d < 16; d *= 2, dsh++) { int edgetype = ((tile >> (TILE_WIRE_ON_EDGE_SHIFT + 2*dsh)) & 3); if (edgetype == 0) continue; /* there isn't a wire on the edge */ if (!(tile & TILE_ROTATING) && ((tile >> (TILE_WIRE_SHIFT + 2*dsh)) & 3) != 0) continue; /* wire on edge would be overdrawn anyway */ for (pass = 0; pass < 2; pass++) { int x, y, w, h; int col = (pass == 0 || edgetype == 1 ? COL_WIRE : edgetype == 2 ? COL_POWERED : COL_ERR); int halfwidth = pass == 0 ? 2*LINE_THICK-1 : LINE_THICK-1; if (X(d) < 0) { x = tx; w = border_tl; } else if (X(d) > 0) { x = tx + TILE_SIZE - border_br; w = border_br; } else { x = cx - halfwidth; w = 2 * halfwidth + 1; } if (Y(d) < 0) { y = ty; h = border_tl; } else if (Y(d) > 0) { y = ty + TILE_SIZE - border_br; h = border_br; } else { y = cy - halfwidth; h = 2 * halfwidth + 1; } draw_rect(dr, x, y, w, h, col); } } /* * Set up the rotation matrix for the main cell contents, i.e. * everything that is centred in the grid square and optionally * rotated by an arbitrary angle about that centre point. */ if (tile & TILE_ROTATING) { matrix[0] = (float)cos(angle * (float)PI / 180.0F); matrix[2] = (float)sin(angle * (float)PI / 180.0F); } else { matrix[0] = 1.0F; matrix[2] = 0.0F; } matrix[3] = matrix[0]; matrix[1] = -matrix[2]; /* * Draw the wires. */ draw_wires(dr, cx, cy, radius, tile, 0xE, COL_WIRE, 2*LINE_THICK-1, matrix); draw_wires(dr, cx, cy, radius, tile, 0x4, COL_POWERED, LINE_THICK-1, matrix); draw_wires(dr, cx, cy, radius, tile, 0x8, COL_ERR, LINE_THICK-1, matrix); /* * Draw the central box. */ for (pass = 0; pass < 2; pass++) { int endtype = (tile >> TILE_ENDPOINT_SHIFT) & 3; if (endtype) { int i, points[8], col; float boxr = TILE_SIZE * 0.24F + (pass == 0 ? LINE_THICK-1 : 0); col = (pass == 0 || endtype == 3 ? COL_WIRE : endtype == 2 ? COL_POWERED : COL_ENDPOINT); points[0] = +1; points[1] = +1; points[2] = +1; points[3] = -1; points[4] = -1; points[5] = -1; points[6] = -1; points[7] = +1; for (i = 0; i < 8; i += 2) { float x, y; rotated_coords(&x, &y, matrix, cx, cy, boxr * points[i], boxr * points[i+1]); points[i] = x + 0.5F; points[i+1] = y + 0.5F; } draw_polygon(dr, points, 4, col, COL_WIRE); } } /* * Draw barriers along grid edges. */ for (pass = 0; pass < 2; pass++) { int btl = border_tl, bbr = border_br, col = COL_BARRIER; if (pass == 0) { btl += barrier_outline_thick; bbr += barrier_outline_thick; col = COL_WIRE; } if (tile & (L << TILE_BARRIER_SHIFT)) draw_rect(dr, tx, ty, btl, TILE_SIZE, col); if (tile & (R << TILE_BARRIER_SHIFT)) draw_rect(dr, tx+TILE_SIZE-bbr, ty, bbr, TILE_SIZE, col); if (tile & (U << TILE_BARRIER_SHIFT)) draw_rect(dr, tx, ty, TILE_SIZE, btl, col); if (tile & (D << TILE_BARRIER_SHIFT)) draw_rect(dr, tx, ty+TILE_SIZE-bbr, TILE_SIZE, bbr, col); if (tile & (R << TILE_BARRIER_CORNER_SHIFT)) draw_rect(dr, tx+TILE_SIZE-bbr, ty, bbr, btl, col); if (tile & (U << TILE_BARRIER_CORNER_SHIFT)) draw_rect(dr, tx, ty, btl, btl, col); if (tile & (L << TILE_BARRIER_CORNER_SHIFT)) draw_rect(dr, tx, ty+TILE_SIZE-bbr, btl, bbr, col); if (tile & (D << TILE_BARRIER_CORNER_SHIFT)) draw_rect(dr, tx+TILE_SIZE-bbr, ty+TILE_SIZE-bbr, bbr, bbr, col); } /* * Unclip and draw update, to finish. */ unclip(dr); draw_update(dr, clipx, clipy, clipw, cliph); } static void game_redraw(drawing *dr, game_drawstate *ds, const game_state *oldstate, const game_state *state, int dir, const game_ui *ui, float t, float ft) { int tx, ty, dx, dy, d, dsh, last_rotate_dir, frame; unsigned char *active; int *loops; float angle = 0.0; tx = ty = -1; last_rotate_dir = dir==-1 ? oldstate->last_rotate_dir : state->last_rotate_dir; if (oldstate && (t < ROTATE_TIME) && last_rotate_dir) { /* * We're animating a single tile rotation. Find the turning * tile. */ tx = (dir==-1 ? oldstate->last_rotate_x : state->last_rotate_x); ty = (dir==-1 ? oldstate->last_rotate_y : state->last_rotate_y); angle = last_rotate_dir * dir * 90.0F * (t / ROTATE_TIME); state = oldstate; } if (ft > 0) { /* * We're animating a completion flash. Find which frame * we're at. */ frame = (int)(ft / FLASH_FRAME); } else { frame = 0; } /* * Build up a map of what we want every tile to look like. We * include tiles one square outside the grid, for the outer edges * of barriers. */ active = compute_active(state, ui->cx, ui->cy); loops = compute_loops(state); for (dy = -1; dy < ds->height+1; dy++) { for (dx = -1; dx < ds->width+1; dx++) { todraw(ds, dx, dy) = 0; } } for (dy = 0; dy < ds->height; dy++) { int gy = (dy + ui->org_y) % ds->height; for (dx = 0; dx < ds->width; dx++) { int gx = (dx + ui->org_x) % ds->width; int t = (tile(state, gx, gy) | index(state, loops, gx, gy) | index(state, active, gx, gy)); for (d = 1, dsh = 0; d < 16; d *= 2, dsh++) { if (barrier(state, gx, gy) & d) { todraw(ds, dx, dy) |= d << TILE_BARRIER_SHIFT; todraw(ds, dx + X(d), dy + Y(d)) |= F(d) << TILE_BARRIER_SHIFT; todraw(ds, dx + X(A(d)), dy + Y(A(d))) |= C(d) << TILE_BARRIER_CORNER_SHIFT; todraw(ds, dx + X(A(d)) + X(d), dy + Y(A(d)) + Y(d)) |= F(d) << TILE_BARRIER_CORNER_SHIFT; todraw(ds, dx + X(C(d)), dy + Y(C(d))) |= d << TILE_BARRIER_CORNER_SHIFT; todraw(ds, dx + X(C(d)) + X(d), dy + Y(C(d)) + Y(d)) |= A(d) << TILE_BARRIER_CORNER_SHIFT; } if (t & d) { int edgeval; /* Highlight as an error any edge in a locked tile that * is adjacent to a lack-of-edge in another locked tile, * or to a barrier */ if (t & LOCKED) { if (barrier(state, gx, gy) & d) { t |= ERR(d); } else { int ox, oy, t2; OFFSET(ox, oy, gx, gy, d, state); t2 = tile(state, ox, oy); if ((t2 & LOCKED) && !(t2 & F(d))) { t |= ERR(d); } } } edgeval = (t & ERR(d) ? 3 : t & ACTIVE ? 2 : 1); todraw(ds, dx, dy) |= edgeval << (TILE_WIRE_SHIFT + dsh*2); if (!(gx == tx && gy == ty)) { todraw(ds, dx + X(d), dy + Y(d)) |= edgeval << (TILE_WIRE_ON_EDGE_SHIFT + (dsh ^ 2)*2); } } } if (ui->cur_visible && gx == ui->cur_x && gy == ui->cur_y) todraw(ds, dx, dy) |= TILE_KEYBOARD_CURSOR; if (gx == tx && gy == ty) todraw(ds, dx, dy) |= TILE_ROTATING; if (gx == ui->cx && gy == ui->cy) { todraw(ds, dx, dy) |= 3 << TILE_ENDPOINT_SHIFT; } else if ((t & 0xF) != R && (t & 0xF) != U && (t & 0xF) != L && (t & 0xF) != D) { /* this is not an endpoint tile */ } else if (t & ACTIVE) { todraw(ds, dx, dy) |= 2 << TILE_ENDPOINT_SHIFT; } else { todraw(ds, dx, dy) |= 1 << TILE_ENDPOINT_SHIFT; } if (t & LOCKED) todraw(ds, dx, dy) |= TILE_LOCKED; /* * In a completion flash, we adjust the LOCKED bit * depending on our distance from the centre point and * the frame number. */ if (frame >= 0) { int rcx = (ui->cx + ds->width - ui->org_x) % ds->width; int rcy = (ui->cy + ds->height - ui->org_y) % ds->height; int xdist, ydist, dist; xdist = (dx < rcx ? rcx - dx : dx - rcx); ydist = (dy < rcy ? rcy - dy : dy - rcy); dist = (xdist > ydist ? xdist : ydist); if (frame >= dist && frame < dist+4 && ((frame - dist) & 1)) todraw(ds, dx, dy) ^= TILE_LOCKED; } } } /* * Now draw any tile that differs from the way it was last drawn. * An exception is that if either the previous _or_ current state * has the TILE_ROTATING bit set, we must draw it regardless, * because it will have rotated to a different angle.q */ for (dy = -1; dy < ds->height+1; dy++) { for (dx = -1; dx < ds->width+1; dx++) { int prev = visible(ds, dx, dy); int curr = todraw(ds, dx, dy); if (prev != curr || ((prev | curr) & TILE_ROTATING) != 0) { draw_tile(dr, ds, dx, dy, curr, angle); visible(ds, dx, dy) = curr; } } } /* * Update the status bar. */ { char statusbuf[256], *p; int i, n, n2, a; bool complete = false; p = statusbuf; *p = '\0'; /* ensure even an empty status string is terminated */ if (state->used_solve) { p += sprintf(p, "Auto-solved. "); complete = true; } else if (state->completed) { p += sprintf(p, "COMPLETED! "); complete = true; } /* * Omit the 'Active: n/N' counter completely if the source * tile is a completely empty one, because then the active * count can't help but read '1'. */ if (tile(state, ui->cx, ui->cy) & 0xF) { n = state->width * state->height; for (i = a = n2 = 0; i < n; i++) { if (active[i]) a++; if (state->tiles[i] & 0xF) n2++; } /* * Also, if we're displaying a completion indicator and * the game is still in its completed state (i.e. every * tile is active), we might as well omit this too. */ if (!complete || a < n2) p += sprintf(p, "Active: %d/%d", a, n2); } status_bar(dr, statusbuf); } sfree(active); sfree(loops); } static float game_anim_length(const game_state *oldstate, const game_state *newstate, int dir, game_ui *ui) { int last_rotate_dir; /* * Don't animate if last_rotate_dir is zero. */ last_rotate_dir = dir==-1 ? oldstate->last_rotate_dir : newstate->last_rotate_dir; if (last_rotate_dir) return ROTATE_TIME; return 0.0F; } static float game_flash_length(const game_state *oldstate, const game_state *newstate, int dir, game_ui *ui) { /* * If the game has just been completed, we display a completion * flash. */ if (!oldstate->completed && newstate->completed && !oldstate->used_solve && !newstate->used_solve) { int size = 0; if (size < newstate->width) size = newstate->width; if (size < newstate->height) size = newstate->height; return FLASH_FRAME * (size+4); } return 0.0F; } static void game_get_cursor_location(const game_ui *ui, const game_drawstate *ds, const game_state *state, const game_params *params, int *x, int *y, int *w, int *h) { if(ui->cur_visible) { *x = WINDOW_OFFSET + TILE_SIZE * ui->cur_x; *y = WINDOW_OFFSET + TILE_SIZE * ui->cur_y; *w = *h = TILE_SIZE; } } static int game_status(const game_state *state) { return state->completed ? +1 : 0; } static void game_print_size(const game_params *params, float *x, float *y) { int pw, ph; /* * I'll use 8mm squares by default. */ game_compute_size(params, 800, &pw, &ph); *x = pw / 100.0F; *y = ph / 100.0F; } static void draw_diagram(drawing *dr, game_drawstate *ds, int x, int y, bool topleft, int v, bool drawlines, int ink) { int tx, ty, cx, cy, r, br, k, thick; tx = WINDOW_OFFSET + TILE_SIZE * x; ty = WINDOW_OFFSET + TILE_SIZE * y; /* * Find our centre point. */ if (topleft) { cx = tx + (v & L ? TILE_SIZE / 4 : TILE_SIZE / 6); cy = ty + (v & U ? TILE_SIZE / 4 : TILE_SIZE / 6); r = TILE_SIZE / 8; br = TILE_SIZE / 32; } else { cx = tx + TILE_SIZE / 2; cy = ty + TILE_SIZE / 2; r = TILE_SIZE / 2; br = TILE_SIZE / 8; } thick = r / 20; /* * Draw the square block if we have an endpoint. */ if (v == 1 || v == 2 || v == 4 || v == 8) draw_rect(dr, cx - br, cy - br, br*2, br*2, ink); /* * Draw each radial line. */ if (drawlines) { for (k = 1; k < 16; k *= 2) if (v & k) { int x1 = min(cx, cx + (r-thick) * X(k)); int x2 = max(cx, cx + (r-thick) * X(k)); int y1 = min(cy, cy + (r-thick) * Y(k)); int y2 = max(cy, cy + (r-thick) * Y(k)); draw_rect(dr, x1 - thick, y1 - thick, (x2 - x1) + 2*thick, (y2 - y1) + 2*thick, ink); } } } static void game_print(drawing *dr, const game_state *state, int tilesize) { int w = state->width, h = state->height; int ink = print_mono_colour(dr, 0); int x, y; /* Ick: fake up `ds->tilesize' for macro expansion purposes */ game_drawstate ads, *ds = &ads; game_set_size(dr, ds, NULL, tilesize); /* * Border. */ print_line_width(dr, TILE_SIZE / (state->wrapping ? 128 : 12)); draw_rect_outline(dr, WINDOW_OFFSET, WINDOW_OFFSET, TILE_SIZE * w, TILE_SIZE * h, ink); /* * Grid. */ print_line_width(dr, TILE_SIZE / 128); for (x = 1; x < w; x++) draw_line(dr, WINDOW_OFFSET + TILE_SIZE * x, WINDOW_OFFSET, WINDOW_OFFSET + TILE_SIZE * x, WINDOW_OFFSET + TILE_SIZE * h, ink); for (y = 1; y < h; y++) draw_line(dr, WINDOW_OFFSET, WINDOW_OFFSET + TILE_SIZE * y, WINDOW_OFFSET + TILE_SIZE * w, WINDOW_OFFSET + TILE_SIZE * y, ink); /* * Barriers. */ for (y = 0; y <= h; y++) for (x = 0; x <= w; x++) { int b = barrier(state, x % w, y % h); if (x < w && (b & U)) draw_rect(dr, WINDOW_OFFSET + TILE_SIZE * x - TILE_SIZE/24, WINDOW_OFFSET + TILE_SIZE * y - TILE_SIZE/24, TILE_SIZE + TILE_SIZE/24 * 2, TILE_SIZE/24 * 2, ink); if (y < h && (b & L)) draw_rect(dr, WINDOW_OFFSET + TILE_SIZE * x - TILE_SIZE/24, WINDOW_OFFSET + TILE_SIZE * y - TILE_SIZE/24, TILE_SIZE/24 * 2, TILE_SIZE + TILE_SIZE/24 * 2, ink); } /* * Grid contents. */ for (y = 0; y < h; y++) for (x = 0; x < w; x++) { int vx, v = tile(state, x, y); int locked = v & LOCKED; v &= 0xF; /* * Rotate into a standard orientation for the top left * corner diagram. */ vx = v; while (vx != 0 && vx != 15 && vx != 1 && vx != 9 && vx != 13 && vx != 5) vx = A(vx); /* * Draw the top left corner diagram. */ draw_diagram(dr, ds, x, y, true, vx, true, ink); /* * Draw the real solution diagram, if we're doing so. */ draw_diagram(dr, ds, x, y, false, v, locked, ink); } } #ifdef COMBINED #define thegame net #endif const struct game thegame = { "Net", "games.net", "net", default_params, game_fetch_preset, NULL, decode_params, encode_params, free_params, dup_params, true, game_configure, custom_params, validate_params, new_game_desc, validate_desc, new_game, dup_game, free_game, true, solve_game, false, NULL, NULL, /* can_format_as_text_now, text_format */ new_ui, free_ui, encode_ui, decode_ui, NULL, /* game_request_keys */ game_changed_state, current_key_label, interpret_move, execute_move, PREFERRED_TILE_SIZE, game_compute_size, game_set_size, game_colours, game_new_drawstate, game_free_drawstate, game_redraw, game_anim_length, game_flash_length, game_get_cursor_location, game_status, true, false, game_print_size, game_print, true, /* wants_statusbar */ false, NULL, /* timing_state */ 0, /* flags */ };