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palisade.c
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palisade.c
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/* -*- indent-tabs-mode: nil; tab-width: 1000 -*- */
/*
* palisade.c: Nikoli's `Five Cells' puzzle.
*
* See http://nikoli.co.jp/en/puzzles/five_cells.html
*/
/* TODO:
*
* - better solver: implement the sketched-out deductions
*
* - improve the victory flash?
* - the LINE_NOs look ugly against COL_FLASH.
* - white-blink the edges (instead), a la loopy?
*/
#include <assert.h>
#include <ctype.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "puzzles.h"
#define setmem(ptr, byte, len) memset((ptr), (byte), (len) * sizeof (ptr)[0])
#define scopy(dst, src, len) memcpy((dst), (src), (len) * sizeof (dst)[0])
#define dupmem(p, n) memcpy(smalloc(n * sizeof (*p)), p, n * sizeof (*p))
#define snewa(ptr, len) (ptr) = smalloc((len) * sizeof (*ptr))
#define clone(ptr) (dupmem((ptr), 1))
static char *string(int n, const char *fmt, ...)
{
va_list va;
char *ret;
int m;
va_start(va, fmt);
m = vsprintf(snewa(ret, n + 1), fmt, va);
va_end(va);
if (m > n) fatal("memory corruption");
return ret;
}
struct game_params {
int w, h, k;
};
typedef char clue;
typedef unsigned char borderflag;
typedef struct shared_state {
game_params params;
clue *clues;
int refcount;
} shared_state;
struct game_state {
shared_state *shared;
borderflag *borders; /* length w*h */
unsigned int completed: 1;
unsigned int cheated: 1;
};
#define DEFAULT_PRESET 0
static struct game_params presets[] = {
{5, 5, 5}, {8, 6, 6}, {10, 8, 8}, {15, 12, 10}
/* I definitely want 5x5n5 since that gives "Five Cells" its name.
* But how about the others? By which criteria do I choose? */
};
static game_params *default_params(void)
{
return clone(&presets[DEFAULT_PRESET]);
}
static int game_fetch_preset(int i, char **name, game_params **params)
{
if (i < 0 || i >= lenof(presets)) return FALSE;
*params = clone(&presets[i]);
*name = string(60, "%d x %d, regions of size %d",
presets[i].w, presets[i].h, presets[i].k);
return TRUE;
}
static void free_params(game_params *params)
{
sfree(params);
}
static game_params *dup_params(const game_params *params)
{
return clone(params);
}
static void decode_params(game_params *params, char const *string)
{
params->w = params->h = params->k = atoi(string);
while (*string && isdigit((unsigned char)*string)) ++string;
if (*string == 'x') {
params->h = atoi(++string);
while (*string && isdigit((unsigned char)*string)) ++string;
}
if (*string == 'n') params->k = atoi(++string);
}
static char *encode_params(const game_params *params, int full)
{
return string(40, "%dx%dn%d", params->w, params->h, params->k);
}
#define CONFIG(i, nm, ty, iv, sv) \
(ret[i].name = nm, ret[i].type = ty, ret[i].ival = iv, ret[i].sval = sv)
static config_item *game_configure(const game_params *params)
{
config_item *ret = snewn(4, config_item);
CONFIG(0, "Width", C_STRING, 0, string(20, "%d", params->w));
CONFIG(1, "Height", C_STRING, 0, string(20, "%d", params->h));
CONFIG(2, "Region size", C_STRING, 0, string(20, "%d", params->k));
CONFIG(3, NULL, C_END, 0, NULL);
return ret;
}
static game_params *custom_params(const config_item *cfg)
{
game_params *params = snew(game_params);
params->w = atoi(cfg[0].sval);
params->h = atoi(cfg[1].sval);
params->k = atoi(cfg[2].sval);
return params;
}
/* +---+ << The one possible domino (up to symmetry). +---+---+
* | 3 | | 3 | 3 |
* | | If two dominos are adjacent as depicted here >> +---+---+
* | 3 | then it's ambiguous whether the edge between | 3 | 3 |
* +---+ the dominos is horizontal or vertical. +---+---+
*/
static char *validate_params(const game_params *params, int full)
{
int w = params->w, h = params->h, k = params->k, wh = w * h;
if (k < 1) return "Region size must be at least one";
if (w < 1) return "Width must be at least one";
if (h < 1) return "Height must be at least one";
if (wh % k) return "Region size must divide grid area";
if (!full) return NULL; /* succeed partial validation */
/* MAYBE FIXME: we (just?) don't have the UI for winning these. */
if (k == wh) return "Region size must be less than the grid area";
assert (k < wh); /* or wh % k != 0 */
if (k == 2 && w != 1 && h != 1)
return "Region size can't be two unless width or height is one";
return NULL; /* succeed full validation */
}
/* --- Solver ------------------------------------------------------- */
/* the solver may write at will to these arrays, but shouldn't free them */
/* it's up to the client to dup/free as needed */
typedef struct solver_ctx {
const game_params *params; /* also in shared_state */
clue *clues; /* also in shared_state */
borderflag *borders; /* also in game_state */
int *dsf; /* particular to the solver */
} solver_ctx;
/* Deductions:
*
* - If two adjacent clues do not have a border between them, this
* gives a lower limit on the size of their region (which is also an
* upper limit if both clues are 3). Rule out any non-border which
* would make its region either too large or too small.
*
* - If a clue, k, is adjacent to k borders or (4 - k) non-borders,
* the remaining edges incident to the clue are readily decided.
*
* - If a region has only one other region (e.g. square) to grow into
* and it's not of full size yet, grow it into that one region.
*
* - If two regions are adjacent and their combined size would be too
* large, put an edge between them.
*
* - If a border is adjacent to two non-borders, its last vertex-mate
* must also be a border. If a maybe-border is adjacent to three
* nonborders, the maybe-border is a non-border.
*
* - If a clue square is adjacent to several squares belonging to the
* same region, and enabling (disabling) those borders would violate
* the clue, those borders must be disabled (enabled).
*
* - If there's a path crossing only non-borders between two squares,
* the maybe-border between them is a non-border.
* (This is implicitly computed in the dsf representation)
*/
/* TODO deductions:
*
* If a vertex is adjacent to a LINE_YES and (4-3)*LINE_NO, at least
* one of the last two edges are LINE_YES. If they're adjacent to a
* 1, then the other two edges incident to that 1 are LINE_NO.
*
* For each square: set all as unknown, then for each k-omino and each
* way of placing it on that square, if that way is consistent with
* the board, mark its edges and interior as possible LINE_YES and
* LINE_NO, respectively. When all k-ominos are through, see what
* isn't possible and remove those impossibilities from the board.
* (Sounds pretty nasty for k > 4 or so.)
*
* A black-bordered subregion must have a size divisible by k. So,
* draw a graph with one node per dsf component and edges between
* those dsf components which have adjacent squares. Identify cut
* vertices and edges. If a cut-vertex-delimited component contains a
* number of squares not divisible by k, cut vertex not included, then
* the cut vertex must belong to the component. If it has exactly one
* edge _out_ of the component, the line(s) corresponding to that edge
* are all LINE_YES (i.e. a BORDER()).
* (This sounds complicated, but visually it is rather easy.)
*
* [Look at loopy and see how the at-least/-most k out of m edges
* thing is done. See how it is propagated across multiple squares.]
*/
#define EMPTY (~0)
#define BIT(i) (1 << (i))
#define BORDER(i) BIT(i)
#define BORDER_U BORDER(0)
#define BORDER_R BORDER(1)
#define BORDER_D BORDER(2)
#define BORDER_L BORDER(3)
#define FLIP(i) ((i) ^ 2)
#define BORDER_MASK (BORDER_U|BORDER_R|BORDER_D|BORDER_L)
#define DISABLED(border) ((border) << 4)
#define UNDISABLED(border) ((border) >> 4)
static const int dx[4] = { 0, +1, 0, -1};
static const int dy[4] = {-1, 0, +1, 0};
static const int bitcount[16] = {0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4};
/* bitcount[x & BORDER_MASK] == number of enabled borders */
#define COMPUTE_J (-1)
static void connect(solver_ctx *ctx, int i, int j)
{
dsf_merge(ctx->dsf, i, j);
}
static int connected(solver_ctx *ctx, int i, int j, int dir)
{
if (j == COMPUTE_J) j = i + dx[dir] + ctx->params->w*dy[dir];
return dsf_canonify(ctx->dsf, i) == dsf_canonify(ctx->dsf, j);
}
static void disconnect(solver_ctx *ctx, int i, int j, int dir)
{
if (j == COMPUTE_J) j = i + dx[dir] + ctx->params->w*dy[dir];
ctx->borders[i] |= BORDER(dir);
ctx->borders[j] |= BORDER(FLIP(dir));
}
static int disconnected(solver_ctx *ctx, int i, int j, int dir)
{
assert (j == COMPUTE_J || j == i + dx[dir] + ctx->params->w*dy[dir]);
return ctx->borders[i] & BORDER(dir);
}
static int maybe(solver_ctx *ctx, int i, int j, int dir)
{
assert (j == COMPUTE_J || j == i + dx[dir] + ctx->params->w*dy[dir]);
return !disconnected(ctx, i, j, dir) && !connected(ctx, i, j, dir);
/* the ordering is important: disconnected works for invalid
* squares (i.e. out of bounds), connected doesn't. */
}
static void solver_connected_clues_versus_region_size(solver_ctx *ctx)
{
int w = ctx->params->w, h = ctx->params->h, wh = w*h, i, dir;
/* If i is connected to j and i has borders with p of the
* remaining three squares and j with q of the remaining three
* squares, then the region has size at least 1+(3-p) + 1+(3-q).
* If p = q = 3 then the region has size exactly 2. */
for (i = 0; i < wh; ++i) {
if (ctx->clues[i] == EMPTY) continue;
for (dir = 0; dir < 4; ++dir) {
int j = i + dx[dir] + w*dy[dir];
if (disconnected(ctx, i, j, dir)) continue;
if (ctx->clues[j] == EMPTY) continue;
if ((8 - ctx->clues[i] - ctx->clues[j] > ctx->params->k) ||
(ctx->clues[i] == 3 && ctx->clues[j] == 3 &&
ctx->params->k != 2))
{
disconnect(ctx, i, j, dir);
/* changed = TRUE, but this is a one-shot... */
}
}
}
}
static int solver_number_exhausted(solver_ctx *ctx)
{
int w = ctx->params->w, h = ctx->params->h, wh = w*h, i, dir, off;
int changed = FALSE;
for (i = 0; i < wh; ++i) {
if (ctx->clues[i] == EMPTY) continue;
if (bitcount[(ctx->borders[i] & BORDER_MASK)] == ctx->clues[i]) {
for (dir = 0; dir < 4; ++dir) {
int j = i + dx[dir] + w*dy[dir];
if (!maybe(ctx, i, j, dir)) continue;
connect(ctx, i, j);
changed = TRUE;
}
continue;
}
for (off = dir = 0; dir < 4; ++dir) {
int j = i + dx[dir] + w*dy[dir];
if (!disconnected(ctx, i, j, dir) && connected(ctx, i, j, dir))
++off; /* ^^^ bounds checking before ^^^^^ */
}
if (ctx->clues[i] == 4 - off)
for (dir = 0; dir < 4; ++dir) {
int j = i + dx[dir] + w*dy[dir];
if (!maybe(ctx, i, j, dir)) continue;
disconnect(ctx, i, j, dir);
changed = TRUE;
}
}
return changed;
}
static int solver_not_too_big(solver_ctx *ctx)
{
int w = ctx->params->w, h = ctx->params->h, wh = w*h, i, dir;
int changed = FALSE;
for (i = 0; i < wh; ++i) {
int size = dsf_size(ctx->dsf, i);
for (dir = 0; dir < 4; ++dir) {
int j = i + dx[dir] + w*dy[dir];
if (!maybe(ctx, i, j, dir)) continue;
if (size + dsf_size(ctx->dsf, j) <= ctx->params->k) continue;
disconnect(ctx, i, j, dir);
changed = TRUE;
}
}
return changed;
}
static int solver_not_too_small(solver_ctx *ctx)
{
int w = ctx->params->w, h = ctx->params->h, wh = w*h, i, dir;
int *outs, k = ctx->params->k, ci, changed = FALSE;
snewa(outs, wh);
setmem(outs, -1, wh);
for (i = 0; i < wh; ++i) {
ci = dsf_canonify(ctx->dsf, i);
if (dsf_size(ctx->dsf, ci) == k) continue;
for (dir = 0; dir < 4; ++dir) {
int j = i + dx[dir] + w*dy[dir];
if (!maybe(ctx, i, j, dir)) continue;
if (outs[ci] == -1) outs[ci] = dsf_canonify(ctx->dsf, j);
else if (outs[ci] != dsf_canonify(ctx->dsf, j)) outs[ci] = -2;
}
}
for (i = 0; i < wh; ++i) {
int j = outs[i];
if (i != dsf_canonify(ctx->dsf, i)) continue;
if (j < 0) continue;
connect(ctx, i, j); /* only one place for i to grow */
changed = TRUE;
}
sfree(outs);
return changed;
}
static int solver_no_dangling_edges(solver_ctx *ctx)
{
int w = ctx->params->w, h = ctx->params->h, r, c;
int changed = FALSE;
/* for each vertex */
for (r = 1; r < h; ++r)
for (c = 1; c < w; ++c) {
int i = r * w + c, j = i - w - 1, noline = 0, dir;
int squares[4], e = -1, f = -1, de = -1, df = -1;
/* feels hacky: I align these with BORDER_[U0 R1 D2 L3] */
squares[1] = squares[2] = j;
squares[0] = squares[3] = i;
/* for each edge adjacent to the vertex */
for (dir = 0; dir < 4; ++dir)
if (!connected(ctx, squares[dir], COMPUTE_J, dir)) {
df = dir;
f = squares[df];
if (e != -1) continue;
e = f;
de = df;
} else ++noline;
if (4 - noline == 1) {
assert (e != -1);
disconnect(ctx, e, COMPUTE_J, de);
changed = TRUE;
continue;
}
if (4 - noline != 2) continue;
assert (e != -1);
assert (f != -1);
if (ctx->borders[e] & BORDER(de)) {
if (!(ctx->borders[f] & BORDER(df))) {
disconnect(ctx, f, COMPUTE_J, df);
changed = TRUE;
}
} else if (ctx->borders[f] & BORDER(df)) {
disconnect(ctx, e, COMPUTE_J, de);
changed = TRUE;
}
}
return changed;
}
static int solver_equivalent_edges(solver_ctx *ctx)
{
int w = ctx->params->w, h = ctx->params->h, wh = w*h, i, dirj;
int changed = FALSE;
/* if a square is adjacent to two connected squares, the two
* borders (i,j) and (i,k) are either both on or both off. */
for (i = 0; i < wh; ++i) {
int n_on = 0, n_off = 0;
if (ctx->clues[i] < 1 || ctx->clues[i] > 3) continue;
if (ctx->clues[i] == 2 /* don't need it otherwise */)
for (dirj = 0; dirj < 4; ++dirj) {
int j = i + dx[dirj] + w*dy[dirj];
if (disconnected(ctx, i, j, dirj)) ++n_on;
else if (connected(ctx, i, j, dirj)) ++n_off;
}
for (dirj = 0; dirj < 4; ++dirj) {
int j = i + dx[dirj] + w*dy[dirj], dirk;
if (!maybe(ctx, i, j, dirj)) continue;
for (dirk = dirj + 1; dirk < 4; ++dirk) {
int k = i + dx[dirk] + w*dy[dirk];
if (!maybe(ctx, i, k, dirk)) continue;
if (!connected(ctx, j, k, -1)) continue;
if (n_on + 2 > ctx->clues[i]) {
connect(ctx, i, j);
connect(ctx, i, k);
changed = TRUE;
} else if (n_off + 2 > 4 - ctx->clues[i]) {
disconnect(ctx, i, j, dirj);
disconnect(ctx, i, k, dirk);
changed = TRUE;
}
}
}
}
return changed;
}
#define UNVISITED 6
/* build connected components in `dsf', along the lines of `borders'. */
static void dfs_dsf(int i, int w, borderflag *border, int *dsf, int black)
{
int dir;
for (dir = 0; dir < 4; ++dir) {
int ii = i + dx[dir] + w*dy[dir], bdir = BORDER(dir);
if (black ? (border[i] & bdir) : !(border[i] & DISABLED(bdir)))
continue;
if (dsf[ii] != UNVISITED) continue;
dsf_merge(dsf, i, ii);
dfs_dsf(ii, w, border, dsf, black);
}
}
static int is_solved(const game_params *params, clue *clues,
borderflag *border)
{
int w = params->w, h = params->h, wh = w*h, k = params->k;
int i, x, y;
int *dsf = snew_dsf(wh);
assert (dsf[0] == UNVISITED); /* check: UNVISITED and dsf.c match up */
/*
* A game is solved if:
*
* - the borders drawn on the grid divide it into connected
* components such that every square is in a component of the
* correct size
* - the borders also satisfy the clue set
*/
for (i = 0; i < wh; ++i) {
if (dsf[i] == UNVISITED) dfs_dsf(i, params->w, border, dsf, TRUE);
if (dsf_size(dsf, i) != k) goto error;
if (clues[i] == EMPTY) continue;
if (clues[i] != bitcount[border[i] & BORDER_MASK]) goto error;
}
/*
* ... and thirdly:
*
* - there are no *stray* borders, in that every border is
* actually part of the division between two components.
* Otherwise you could cheat by finding a subdivision which did
* not *exceed* any clue square's counter, and then adding a
* few extra edges.
*/
for (y = 0; y < h; y++) {
for (x = 0; x < w; x++) {
if (x+1 < w && (border[y*w+x] & BORDER_R) &&
dsf_canonify(dsf, y*w+x) == dsf_canonify(dsf, y*w+(x+1)))
goto error;
if (y+1 < h && (border[y*w+x] & BORDER_D) &&
dsf_canonify(dsf, y*w+x) == dsf_canonify(dsf, (y+1)*w+x))
goto error;
}
}
sfree(dsf);
return TRUE;
error:
sfree(dsf);
return FALSE;
}
static int solver(const game_params *params, clue *clues, borderflag *borders)
{
int w = params->w, h = params->h, wh = w*h, changed;
solver_ctx ctx;
ctx.params = params;
ctx.clues = clues;
ctx.borders = borders;
ctx.dsf = snew_dsf(wh);
solver_connected_clues_versus_region_size(&ctx); /* idempotent */
do {
changed = FALSE;
changed |= solver_number_exhausted(&ctx);
changed |= solver_not_too_big(&ctx);
changed |= solver_not_too_small(&ctx);
changed |= solver_no_dangling_edges(&ctx);
changed |= solver_equivalent_edges(&ctx);
} while (changed);
sfree(ctx.dsf);
return is_solved(params, clues, borders);
}
/* --- Generator ---------------------------------------------------- */
static void init_borders(int w, int h, borderflag *borders)
{
int r, c;
setmem(borders, 0, w*h);
for (c = 0; c < w; ++c) {
borders[c] |= BORDER_U;
borders[w*h-1 - c] |= BORDER_D;
}
for (r = 0; r < h; ++r) {
borders[r*w] |= BORDER_L;
borders[w*h-1 - r*w] |= BORDER_R;
}
}
#define OUT_OF_BOUNDS(x, y, w, h) \
((x) < 0 || (x) >= (w) || (y) < 0 || (y) >= (h))
#define xshuffle(ptr, len, rs) shuffle((ptr), (len), sizeof (ptr)[0], (rs))
static char *new_game_desc(const game_params *params, random_state *rs,
char **aux, int interactive)
{
int w = params->w, h = params->h, wh = w*h, k = params->k;
clue *numbers = snewn(wh + 1, clue), *p;
borderflag *rim = snewn(wh, borderflag);
borderflag *scratch_borders = snewn(wh, borderflag);
char *soln = snewa(*aux, wh + 2);
int *shuf = snewn(wh, int);
int *dsf = NULL, i, r, c;
int attempts = 0;
for (i = 0; i < wh; ++i) shuf[i] = i;
xshuffle(shuf, wh, rs);
init_borders(w, h, rim);
assert (!('@' & BORDER_MASK));
*soln++ = 'S';
soln[wh] = '\0';
do {
++attempts;
setmem(soln, '@', wh);
sfree(dsf);
dsf = divvy_rectangle(w, h, k, rs);
for (r = 0; r < h; ++r)
for (c = 0; c < w; ++c) {
int i = r * w + c, dir;
numbers[i] = 0;
for (dir = 0; dir < 4; ++dir) {
int rr = r + dy[dir], cc = c + dx[dir], ii = rr * w + cc;
if (OUT_OF_BOUNDS(cc, rr, w, h) ||
dsf_canonify(dsf, i) != dsf_canonify(dsf, ii)) {
++numbers[i];
soln[i] |= BORDER(dir);
}
}
}
scopy(scratch_borders, rim, wh);
} while (!solver(params, numbers, scratch_borders));
for (i = 0; i < wh; ++i) {
int j = shuf[i];
clue copy = numbers[j];
scopy(scratch_borders, rim, wh);
numbers[j] = EMPTY; /* strip away unnecssary clues */
if (!solver(params, numbers, scratch_borders))
numbers[j] = copy;
}
numbers[wh] = '\0';
sfree(scratch_borders);
sfree(rim);
sfree(shuf);
sfree(dsf);
p = numbers;
r = 0;
for (i = 0; i < wh; ++i) {
if (numbers[i] != EMPTY) {
while (r) {
while (r > 26) {
*p++ = 'z';
r -= 26;
}
*p++ = 'a'-1 + r;
r = 0;
}
*p++ = '0' + numbers[i];
} else ++r;
}
*p++ = '\0';
return sresize(numbers, p - numbers, clue);
}
static char *validate_desc(const game_params *params, const char *desc)
{
int w = params->w, h = params->h, wh = w*h, squares = 0;
for (/* nop */; *desc; ++desc) {
if (islower((unsigned char)*desc)) {
squares += *desc - 'a' + 1;
} else if (isdigit((unsigned char)*desc)) {
if (*desc > '4') {
static char buf[] = "Invalid (too large) number: '5'";
assert (isdigit((unsigned char)buf[lenof(buf) - 3]));
buf[lenof(buf) - 3] = *desc; /* ... or 6, 7, 8, 9 :-) */
return buf;
}
++squares;
} else if (isprint((unsigned char)*desc)) {
static char buf[] = "Invalid character in data: '?'";
buf[lenof(buf) - 3] = *desc;
return buf;
} else return "Invalid (unprintable) character in data";
}
if (squares > wh) return "Data describes too many squares";
return NULL;
}
static game_state *new_game(midend *me, const game_params *params,
const char *desc)
{
int w = params->w, h = params->h, wh = w*h, i;
game_state *state = snew(game_state);
state->shared = snew(shared_state);
state->shared->refcount = 1;
state->shared->params = *params; /* struct copy */
snewa(state->shared->clues, wh);
setmem(state->shared->clues, EMPTY, wh);
for (i = 0; *desc; ++desc) {
if (isdigit((unsigned char)*desc)) state->shared->clues[i++] = *desc - '0';
else if (isalpha((unsigned char)*desc)) i += *desc - 'a' + 1;
}
snewa(state->borders, wh);
init_borders(w, h, state->borders);
state->completed = (params->k == wh);
state->cheated = FALSE;
return state;
}
static game_state *dup_game(const game_state *state)
{
int wh = state->shared->params.w * state->shared->params.h;
game_state *ret = snew(game_state);
ret->borders = dupmem(state->borders, wh);
ret->shared = state->shared;
++ret->shared->refcount;
ret->completed = state->completed;
ret->cheated = state->cheated;
return ret;
}
static void free_game(game_state *state)
{
if (--state->shared->refcount == 0) {
sfree(state->shared->clues);
sfree(state->shared);
}
sfree(state->borders);
sfree(state);
}
static char *solve_game(const game_state *state, const game_state *currstate,
const char *aux, char **error)
{
int w = state->shared->params.w, h = state->shared->params.h, wh = w*h;
borderflag *move;
if (aux) return dupstr(aux);
snewa(move, wh + 2);
move[0] = 'S';
init_borders(w, h, move + 1);
move[wh + 1] = '\0';
if (solver(&state->shared->params, state->shared->clues, move + 1)) {
int i;
for (i = 0; i < wh; i++)
move[i+1] |= '@'; /* turn into sensible ASCII */
return (char *) move;
}
*error = "Sorry, I can't solve this puzzle";
sfree(move);
return NULL;
{
/* compile-time-assert (borderflag is-a-kind-of char).
*
* depends on zero-size arrays being disallowed. GCC says
* ISO C forbids this, pointing to [-Werror=edantic]. Also,
* it depends on type-checking of (obviously) dead code. */
borderflag b[sizeof (borderflag) == sizeof (char)];
char c = b[0]; b[0] = c;
/* we could at least in principle put this anywhere, but it
* seems silly to not put it where the assumption is used. */
}
}
static int game_can_format_as_text_now(const game_params *params)
{
return TRUE;
}
static char *game_text_format(const game_state *state)
{
int w = state->shared->params.w, h = state->shared->params.h, r, c;
int cw = 4, ch = 2, gw = cw*w + 2, gh = ch * h + 1, len = gw * gh;
char *board;
setmem(snewa(board, len + 1), ' ', len);
for (r = 0; r < h; ++r) {
for (c = 0; c < w; ++c) {
int cell = r*ch*gw + cw*c, center = cell + gw*ch/2 + cw/2;
int i = r * w + c, clue = state->shared->clues[i];
if (clue != EMPTY) board[center] = '0' + clue;
board[cell] = '+';
if (state->borders[i] & BORDER_U)
setmem(board + cell + 1, '-', cw - 1);
else if (state->borders[i] & DISABLED(BORDER_U))
board[cell + cw / 2] = 'x';
if (state->borders[i] & BORDER_L)
board[cell + gw] = '|';
else if (state->borders[i] & DISABLED(BORDER_L))
board[cell + gw] = 'x';
}
for (c = 0; c < ch; ++c) {
board[(r*ch + c)*gw + gw - 2] = c ? '|' : '+';
board[(r*ch + c)*gw + gw - 1] = '\n';
}
}
scopy(board + len - gw, board, gw);
board[len] = '\0';
return board;
}
struct game_ui {
int x, y;
unsigned int show: 1;
};
static game_ui *new_ui(const game_state *state)
{
game_ui *ui = snew(game_ui);
ui->x = ui->y = 0;
ui->show = FALSE;
return ui;
}
static void free_ui(game_ui *ui)
{
sfree(ui);
}
static char *encode_ui(const game_ui *ui)
{
return NULL;
}
static void decode_ui(game_ui *ui, const char *encoding)
{
assert (encoding == NULL);
}
static void game_changed_state(game_ui *ui, const game_state *oldstate,
const game_state *newstate)
{
}
typedef unsigned short dsflags;
struct game_drawstate {
int tilesize;
dsflags *grid;
};
#define TILESIZE (ds->tilesize)
#define MARGIN (ds->tilesize / 2)
#define WIDTH (1 + (TILESIZE >= 16) + (TILESIZE >= 32) + (TILESIZE >= 64))
#define CENTER ((ds->tilesize / 2) + WIDTH/2)
#define FROMCOORD(x) (((x) - MARGIN) / TILESIZE)
enum {MAYBE_LEFT, MAYBE_RIGHT, ON_LEFT, ON_RIGHT, OFF_LEFT, OFF_RIGHT};
static char *interpret_move(const game_state *state, game_ui *ui,
const game_drawstate *ds, int x, int y, int button)
{
int w = state->shared->params.w, h = state->shared->params.h;
int control = button & MOD_CTRL, shift = button & MOD_SHFT;
button &= ~MOD_MASK;
if (button == LEFT_BUTTON || button == RIGHT_BUTTON) {
int gx = FROMCOORD(x), gy = FROMCOORD(y), possible = BORDER_MASK;
int px = (x - MARGIN) % TILESIZE, py = (y - MARGIN) % TILESIZE;
int hx, hy, dir, i;
if (OUT_OF_BOUNDS(gx, gy, w, h)) return NULL;
ui->x = gx;
ui->y = gy;
/* find edge closest to click point */
possible &=~ (2*px < TILESIZE ? BORDER_R : BORDER_L);
possible &=~ (2*py < TILESIZE ? BORDER_D : BORDER_U);
px = min(px, TILESIZE - px);
py = min(py, TILESIZE - py);
possible &=~ (px < py ? (BORDER_U|BORDER_D) : (BORDER_L|BORDER_R));
for (dir = 0; dir < 4 && BORDER(dir) != possible; ++dir);
if (dir == 4) return NULL; /* there's not exactly one such edge */
hx = gx + dx[dir];
hy = gy + dy[dir];
if (OUT_OF_BOUNDS(hx, hy, w, h)) return NULL;
ui->show = FALSE;
i = gy * w + gx;
switch ((button == RIGHT_BUTTON) |
((state->borders[i] & BORDER(dir)) >> dir << 1) |
((state->borders[i] & DISABLED(BORDER(dir))) >> dir >> 2)) {
case MAYBE_LEFT:
case ON_LEFT:
case ON_RIGHT:
return string(80, "F%d,%d,%dF%d,%d,%d",
gx, gy, BORDER(dir),
hx, hy, BORDER(FLIP(dir)));
case MAYBE_RIGHT:
case OFF_LEFT:
case OFF_RIGHT:
return string(80, "F%d,%d,%dF%d,%d,%d",
gx, gy, DISABLED(BORDER(dir)),
hx, hy, DISABLED(BORDER(FLIP(dir))));
}
}
if (IS_CURSOR_MOVE(button)) {
ui->show = TRUE;
if (control || shift) {
borderflag flag = 0, newflag;
int dir, i = ui->y * w + ui->x;
x = ui->x;
y = ui->y;
move_cursor(button, &x, &y, w, h, FALSE);
if (OUT_OF_BOUNDS(x, y, w, h)) return NULL;
for (dir = 0; dir < 4; ++dir)
if (dx[dir] == x - ui->x && dy[dir] == y - ui->y) break;
if (dir == 4) return NULL; /* how the ... ?! */
if (control) flag |= BORDER(dir);
if (shift) flag |= DISABLED(BORDER(dir));
newflag = state->borders[i] ^ flag;
if (newflag & BORDER(dir) && newflag & DISABLED(BORDER(dir)))
return NULL;
newflag = 0;
if (control) newflag |= BORDER(FLIP(dir));
if (shift) newflag |= DISABLED(BORDER(FLIP(dir)));
return string(80, "F%d,%d,%dF%d,%d,%d",
ui->x, ui->y, flag, x, y, newflag);
} else {
move_cursor(button, &ui->x, &ui->y, w, h, FALSE);
return "";
}
}
return NULL;
}
static game_state *execute_move(const game_state *state, const char *move)
{
int w = state->shared->params.w, h = state->shared->params.h, wh = w * h;
game_state *ret = dup_game(state);
int nchars, x, y, flag;