puzzles: refactor and resync with upstream

This brings puzzles up-to-date with upstream revision
2d333750272c3967cfd5cd3677572cddeaad5932, though certain changes made
by me, including cursor-only Untangle and some compilation fixes
remain. Upstream code has been moved to its separate subdirectory and
future syncs can be done by simply copying over the new sources.

Change-Id: Ia6506ca5f78c3627165ea6791d38db414ace0804

1 files changed, 0 insertions, 2255 deletions

diff --git a/apps/plugins/puzzles/pattern.c b/apps/plugins/puzzles/pattern.c
deleted file mode 100644
index c741a2e..0000000
--- a/apps/plugins/puzzles/pattern.c
+++ /dev/null
@@ -1,2255 +0,0 @@
-/*
- * pattern.c: the pattern-reconstruction game known as `nonograms'.
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include "rbassert.h"
-#include <ctype.h>
-#include <math.h>
-
-#include "puzzles.h"
-
-enum {
-    COL_BACKGROUND,
-    COL_EMPTY,
-    COL_FULL,
-    COL_TEXT,
-    COL_UNKNOWN,
-    COL_GRID,
-    COL_CURSOR,
-    COL_ERROR,
-    NCOLOURS
-};
-
-#define PREFERRED_TILE_SIZE 24
-#define TILE_SIZE (ds->tilesize)
-#define BORDER (3 * TILE_SIZE / 4)
-#define TLBORDER(d) ( (d) / 5 + 2 )
-#define GUTTER (TILE_SIZE / 2)
-
-#define FROMCOORD(d, x) \
-        ( ((x) - (BORDER + GUTTER + TILE_SIZE * TLBORDER(d))) / TILE_SIZE )
-
-#define SIZE(d) (2*BORDER + GUTTER + TILE_SIZE * (TLBORDER(d) + (d)))
-#define GETTILESIZE(d, w) ((double)w / (2.0 + (double)TLBORDER(d) + (double)(d)))
-
-#define TOCOORD(d, x) (BORDER + GUTTER + TILE_SIZE * (TLBORDER(d) + (x)))
-
-struct game_params {
-    int w, h;
-};
-
-#define GRID_UNKNOWN 2
-#define GRID_FULL 1
-#define GRID_EMPTY 0
-
-typedef struct game_state_common {
-    /* Parts of the game state that don't change during play. */
-    int w, h;
-    int rowsize;
-    int *rowdata, *rowlen;
-    unsigned char *immutable;
-    int refcount;
-} game_state_common;
-
-struct game_state {
-    game_state_common *common;
-    unsigned char *grid;
-    int completed, cheated;
-};
-
-#define FLASH_TIME 0.13F
-
-static game_params *default_params(void)
-{
-    game_params *ret = snew(game_params);
-
-    ret->w = ret->h = 15;
-
-    return ret;
-}
-
-static const struct game_params pattern_presets[] = {
-    {10, 10},
-    {15, 15},
-    {20, 20},
-#ifndef SLOW_SYSTEM
-    {25, 25},
-    {30, 30},
-#endif
-};
-
-static int game_fetch_preset(int i, char **name, game_params **params)
-{
-    game_params *ret;
-    char str[80];
-
-    if (i < 0 || i >= lenof(pattern_presets))
-        return FALSE;
-
-    ret = snew(game_params);
-    *ret = pattern_presets[i];
-
-    sprintf(str, "%dx%d", ret->w, ret->h);
-
-    *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->w = atoi(p);
-    while (*p && isdigit((unsigned char)*p)) p++;
-    if (*p == 'x') {
-        p++;
-        ret->h = atoi(p);
-        while (*p && isdigit((unsigned char)*p)) p++;
-    } else {
-        ret->h = ret->w;
-    }
-}
-
-static char *encode_params(const game_params *params, int full)
-{
-    char ret[400];
-    int len;
-
-    len = sprintf(ret, "%dx%d", params->w, params->h);
-    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(3, config_item);
-
-    ret[0].name = "Width";
-    ret[0].type = C_STRING;
-    sprintf(buf, "%d", params->w);
-    ret[0].sval = dupstr(buf);
-    ret[0].ival = 0;
-
-    ret[1].name = "Height";
-    ret[1].type = C_STRING;
-    sprintf(buf, "%d", params->h);
-    ret[1].sval = dupstr(buf);
-    ret[1].ival = 0;
-
-    ret[2].name = NULL;
-    ret[2].type = C_END;
-    ret[2].sval = NULL;
-    ret[2].ival = 0;
-
-    return ret;
-}
-
-static game_params *custom_params(const config_item *cfg)
-{
-    game_params *ret = snew(game_params);
-
-    ret->w = atoi(cfg[0].sval);
-    ret->h = atoi(cfg[1].sval);
-
-    return ret;
-}
-
-static char *validate_params(const game_params *params, int full)
-{
-    if (params->w <= 0 || params->h <= 0)
-	return "Width and height must both be greater than zero";
-    return NULL;
-}
-
-/* ----------------------------------------------------------------------
- * Puzzle generation code.
- * 
- * For this particular puzzle, it seemed important to me to ensure
- * a unique solution. I do this the brute-force way, by having a
- * solver algorithm alongside the generator, and repeatedly
- * generating a random grid until I find one whose solution is
- * unique. It turns out that this isn't too onerous on a modern PC
- * provided you keep grid size below around 30. Any offers of
- * better algorithms, however, will be very gratefully received.
- * 
- * Another annoyance of this approach is that it limits the
- * available puzzles to those solvable by the algorithm I've used.
- * My algorithm only ever considers a single row or column at any
- * one time, which means it's incapable of solving the following
- * difficult example (found by Bella Image around 1995/6, when she
- * and I were both doing maths degrees):
- * 
- *        2  1  2  1 
- *
- *      +--+--+--+--+
- * 1 1  |  |  |  |  |
- *      +--+--+--+--+
- *   2  |  |  |  |  |
- *      +--+--+--+--+
- *   1  |  |  |  |  |
- *      +--+--+--+--+
- *   1  |  |  |  |  |
- *      +--+--+--+--+
- * 
- * Obviously this cannot be solved by a one-row-or-column-at-a-time
- * algorithm (it would require at least one row or column reading
- * `2 1', `1 2', `3' or `4' to get started). However, it can be
- * proved to have a unique solution: if the top left square were
- * empty, then the only option for the top row would be to fill the
- * two squares in the 1 columns, which would imply the squares
- * below those were empty, leaving no place for the 2 in the second
- * row. Contradiction. Hence the top left square is full, and the
- * unique solution follows easily from that starting point.
- * 
- * (The game ID for this puzzle is 4x4:2/1/2/1/1.1/2/1/1 , in case
- * it's useful to anyone.)
- */
-
-#ifndef STANDALONE_PICTURE_GENERATOR
-static int float_compare(const void *av, const void *bv)
-{
-    const float *a = (const float *)av;
-    const float *b = (const float *)bv;
-    if (*a < *b)
-        return -1;
-    else if (*a > *b)
-        return +1;
-    else
-        return 0;
-}
-
-static void generate(random_state *rs, int w, int h, unsigned char *retgrid)
-{
-    float *fgrid;
-    float *fgrid2;
-    int step, i, j;
-    float threshold;
-
-    fgrid = snewn(w*h, float);
-
-    for (i = 0; i < h; i++) {
-        for (j = 0; j < w; j++) {
-            fgrid[i*w+j] = random_upto(rs, 100000000UL) / 100000000.F;
-        }
-    }
-
-    /*
-     * The above gives a completely random splattering of black and
-     * white cells. We want to gently bias this in favour of _some_
-     * reasonably thick areas of white and black, while retaining
-     * some randomness and fine detail.
-     * 
-     * So we evolve the starting grid using a cellular automaton.
-     * Currently, I'm doing something very simple indeed, which is
-     * to set each square to the average of the surrounding nine
-     * cells (or the average of fewer, if we're on a corner).
-     */
-    for (step = 0; step < 1; step++) {
-        fgrid2 = snewn(w*h, float);
-
-        for (i = 0; i < h; i++) {
-            for (j = 0; j < w; j++) {
-                float sx, xbar;
-                int n, p, q;
-
-                /*
-                 * Compute the average of the surrounding cells.
-                 */
-                n = 0;
-                sx = 0.F;
-                for (p = -1; p <= +1; p++) {
-                    for (q = -1; q <= +1; q++) {
-                        if (i+p < 0 || i+p >= h || j+q < 0 || j+q >= w)
-                            continue;
-			/*
-			 * An additional special case not mentioned
-			 * above: if a grid dimension is 2xn then
-			 * we do not average across that dimension
-			 * at all. Otherwise a 2x2 grid would
-			 * contain four identical squares.
-			 */
-			if ((h==2 && p!=0) || (w==2 && q!=0))
-			    continue;
-                        n++;
-                        sx += fgrid[(i+p)*w+(j+q)];
-                    }
-                }
-                xbar = sx / n;
-
-                fgrid2[i*w+j] = xbar;
-            }
-        }
-
-        sfree(fgrid);
-        fgrid = fgrid2;
-    }
-
-    fgrid2 = snewn(w*h, float);
-    memcpy(fgrid2, fgrid, w*h*sizeof(float));
-    qsort(fgrid2, w*h, sizeof(float), float_compare);
-    threshold = fgrid2[w*h/2];
-    sfree(fgrid2);
-
-    for (i = 0; i < h; i++) {
-        for (j = 0; j < w; j++) {
-            retgrid[i*w+j] = (fgrid[i*w+j] >= threshold ? GRID_FULL :
-                              GRID_EMPTY);
-        }
-    }
-
-    sfree(fgrid);
-}
-#endif
-
-static int compute_rowdata(int *ret, unsigned char *start, int len, int step)
-{
-    int i, n;
-
-    n = 0;
-
-    for (i = 0; i < len; i++) {
-        if (start[i*step] == GRID_FULL) {
-            int runlen = 1;
-            while (i+runlen < len && start[(i+runlen)*step] == GRID_FULL)
-                runlen++;
-            ret[n++] = runlen;
-            i += runlen;
-        }
-
-        if (i < len && start[i*step] == GRID_UNKNOWN)
-            return -1;
-    }
-
-    return n;
-}
-
-#define UNKNOWN 0
-#define BLOCK 1
-#define DOT 2
-#define STILL_UNKNOWN 3
-
-#ifdef STANDALONE_SOLVER
-int verbose = FALSE;
-#endif
-
-static int do_recurse(unsigned char *known, unsigned char *deduced,
-                       unsigned char *row,
-		       unsigned char *minpos_done, unsigned char *maxpos_done,
-		       unsigned char *minpos_ok, unsigned char *maxpos_ok,
-		       int *data, int len,
-                       int freespace, int ndone, int lowest)
-{
-    int i, j, k;
-
-
-    /* This algorithm basically tries all possible ways the given rows of
-     * black blocks can be laid out in the row/column being examined.
-     * Special care is taken to avoid checking the tail of a row/column
-     * if the same conditions have already been checked during this recursion
-     * The algorithm also takes care to cut its losses as soon as an
-     * invalid (partial) solution is detected.
-     */
-    if (data[ndone]) {
-	if (lowest >= minpos_done[ndone] && lowest <= maxpos_done[ndone]) {
-	    if (lowest >= minpos_ok[ndone] && lowest <= maxpos_ok[ndone]) {
-		for (i=0; i<lowest; i++)
-		    deduced[i] |= row[i];
-	    }
-	    return lowest >= minpos_ok[ndone] && lowest <= maxpos_ok[ndone];
-	} else {
-	    if (lowest < minpos_done[ndone]) minpos_done[ndone] = lowest;
-	    if (lowest > maxpos_done[ndone]) maxpos_done[ndone] = lowest;
-	}
-	for (i=0; i<=freespace; i++) {
-	    j = lowest;
-	    for (k=0; k<i; k++) {
-		if (known[j] == BLOCK) goto next_iter;
-	        row[j++] = DOT;
-	    }
-	    for (k=0; k<data[ndone]; k++) {
-		if (known[j] == DOT) goto next_iter;
-	        row[j++] = BLOCK;
-	    }
-	    if (j < len) {
-		if (known[j] == BLOCK) goto next_iter;
-	        row[j++] = DOT;
-	    }
-	    if (do_recurse(known, deduced, row, minpos_done, maxpos_done,
-	                   minpos_ok, maxpos_ok, data, len, freespace-i, ndone+1, j)) {
-	        if (lowest < minpos_ok[ndone]) minpos_ok[ndone] = lowest;
-	        if (lowest + i > maxpos_ok[ndone]) maxpos_ok[ndone] = lowest + i;
-	        if (lowest + i > maxpos_done[ndone]) maxpos_done[ndone] = lowest + i;
-	    }
-	    next_iter:
-	    j++;
-	}
-	return lowest >= minpos_ok[ndone] && lowest <= maxpos_ok[ndone];
-    } else {
-	for (i=lowest; i<len; i++) {
-	    if (known[i] == BLOCK) return FALSE;
-	    row[i] = DOT;
-	    }
-	for (i=0; i<len; i++)
-	    deduced[i] |= row[i];
-	return TRUE;
-    }
-}
-
-
-static int do_row(unsigned char *known, unsigned char *deduced,
-                  unsigned char *row,
-                  unsigned char *minpos_done, unsigned char *maxpos_done,
-		  unsigned char *minpos_ok, unsigned char *maxpos_ok,
-                  unsigned char *start, int len, int step, int *data,
-		  unsigned int *changed
-#ifdef STANDALONE_SOLVER
-		  , const char *rowcol, int index, int cluewid
-#endif
-		  )
-{
-    int rowlen, i, freespace, done_any;
-
-    freespace = len+1;
-    for (rowlen = 0; data[rowlen]; rowlen++) {
-	minpos_done[rowlen] = minpos_ok[rowlen] = len - 1;
-	maxpos_done[rowlen] = maxpos_ok[rowlen] = 0;
-	freespace -= data[rowlen]+1;
-    }
-
-    for (i = 0; i < len; i++) {
-	known[i] = start[i*step];
-	deduced[i] = 0;
-    }
-    for (i = len - 1; i >= 0 && known[i] == DOT; i--)
-        freespace--;
-
-    if (rowlen == 0) {
-        memset(deduced, DOT, len);
-    } else {
-        do_recurse(known, deduced, row, minpos_done, maxpos_done, minpos_ok,
-                   maxpos_ok, data, len, freespace, 0, 0);
-    }
-
-    done_any = FALSE;
-    for (i=0; i<len; i++)
-	if (deduced[i] && deduced[i] != STILL_UNKNOWN && !known[i]) {
-	    start[i*step] = deduced[i];
-	    if (changed) changed[i]++;
-	    done_any = TRUE;
-	}
-#ifdef STANDALONE_SOLVER
-    if (verbose && done_any) {
-	char buf[80];
-	int thiscluewid;
-	printf("%s %2d: [", rowcol, index);
-	for (thiscluewid = -1, i = 0; data[i]; i++)
-	    thiscluewid += sprintf(buf, " %d", data[i]);
-	printf("%*s", cluewid - thiscluewid, "");
-	for (i = 0; data[i]; i++)
-	    printf(" %d", data[i]);
-	printf(" ] ");
-	for (i = 0; i < len; i++)
-	    putchar(known[i] == BLOCK ? '#' :
-		    known[i] == DOT ? '.' : '?');
-	printf(" -> ");
-	for (i = 0; i < len; i++)
-	    putchar(start[i*step] == BLOCK ? '#' :
-		    start[i*step] == DOT ? '.' : '?');
-	putchar('\n');
-    }
-#endif
-    return done_any;
-}
-
-static int solve_puzzle(const game_state *state, unsigned char *grid,
-                        int w, int h,
-			unsigned char *matrix, unsigned char *workspace,
-			unsigned int *changed_h, unsigned int *changed_w,
-			int *rowdata
-#ifdef STANDALONE_SOLVER
-			, int cluewid
-#else
-			, int dummy
-#endif
-			)
-{
-    int i, j, ok, max;
-    int max_h, max_w;
-
-    assert((state!=NULL && state->common->rowdata!=NULL) ^ (grid!=NULL));
-
-    max = max(w, h);
-
-    memset(matrix, 0, w*h);
-    if (state) {
-        for (i=0; i<w*h; i++) {
-            if (state->common->immutable[i])
-                matrix[i] = state->grid[i];
-        }
-    }
-
-    /* For each column, compute how many squares can be deduced
-     * from just the row-data and initial clues.
-     * Later, changed_* will hold how many squares were changed
-     * in every row/column in the previous iteration
-     * Changed_* is used to choose the next rows / cols to re-examine
-     */
-    for (i=0; i<h; i++) {
-	int freespace, rowlen;
-	if (state && state->common->rowdata) {
-            memcpy(rowdata, state->common->rowdata + state->common->rowsize*(w+i), max*sizeof(int));
-	    rowlen = state->common->rowlen[w+i];
-	} else {
-	    rowlen = compute_rowdata(rowdata, grid+i*w, w, 1);
-	}
-        rowdata[rowlen] = 0;
-        if (rowlen == 0) {
-            changed_h[i] = w;
-        } else {
-            for (j=0, freespace=w+1; rowdata[j]; j++)
-                freespace -= rowdata[j] + 1;
-            for (j=0, changed_h[i]=0; rowdata[j]; j++)
-                if (rowdata[j] > freespace)
-                    changed_h[i] += rowdata[j] - freespace;
-        }
-        for (j = 0; j < w; j++)
-            if (matrix[i*w+j])
-                changed_h[i]++;
-    }
-    for (i=0,max_h=0; i<h; i++)
-	if (changed_h[i] > max_h)
-	    max_h = changed_h[i];
-    for (i=0; i<w; i++) {
-	int freespace, rowlen;
-	if (state && state->common->rowdata) {
-	    memcpy(rowdata, state->common->rowdata + state->common->rowsize*i, max*sizeof(int));
-	    rowlen = state->common->rowlen[i];
-	} else {
-            rowlen = compute_rowdata(rowdata, grid+i, h, w);
-	}
-        rowdata[rowlen] = 0;
-        if (rowlen == 0) {
-            changed_w[i] = h;
-        } else {
-            for (j=0, freespace=h+1; rowdata[j]; j++)
-                freespace -= rowdata[j] + 1;
-            for (j=0, changed_w[i]=0; rowdata[j]; j++)
-                if (rowdata[j] > freespace)
-                    changed_w[i] += rowdata[j] - freespace;
-        }
-        for (j = 0; j < h; j++)
-            if (matrix[j*w+i])
-                changed_w[i]++;
-    }
-    for (i=0,max_w=0; i<w; i++)
-	if (changed_w[i] > max_w)
-	    max_w = changed_w[i];
-
-    /* Solve the puzzle.
-     * Process rows/columns individually. Deductions involving more than one
-     * row and/or column at a time are not supported.
-     * Take care to only process rows/columns which have been changed since they
-     * were previously processed.
-     * Also, prioritize rows/columns which have had the most changes since their
-     * previous processing, as they promise the greatest benefit.
-     * Extremely rectangular grids (e.g. 10x20, 15x40, etc.) are not treated specially.
-     */
-    do {
-	for (; max_h && max_h >= max_w; max_h--) {
-	    for (i=0; i<h; i++) {
-		if (changed_h[i] >= max_h) {
-		    if (state && state->common->rowdata) {
-			memcpy(rowdata, state->common->rowdata + state->common->rowsize*(w+i), max*sizeof(int));
-			rowdata[state->common->rowlen[w+i]] = 0;
-		    } else {
-			rowdata[compute_rowdata(rowdata, grid+i*w, w, 1)] = 0;
-		    }
-		    do_row(workspace, workspace+max, workspace+2*max,
-			   workspace+3*max, workspace+4*max,
-			   workspace+5*max, workspace+6*max,
-			   matrix+i*w, w, 1, rowdata, changed_w
-#ifdef STANDALONE_SOLVER
-			   , "row", i+1, cluewid
-#endif
-			   );
-		    changed_h[i] = 0;
-		}
-	    }
-	    for (i=0,max_w=0; i<w; i++)
-		if (changed_w[i] > max_w)
-		    max_w = changed_w[i];
-	}
-	for (; max_w && max_w >= max_h; max_w--) {
-	    for (i=0; i<w; i++) {
-		if (changed_w[i] >= max_w) {
-		    if (state && state->common->rowdata) {
-			memcpy(rowdata, state->common->rowdata + state->common->rowsize*i, max*sizeof(int));
-			rowdata[state->common->rowlen[i]] = 0;
-		    } else {
-			rowdata[compute_rowdata(rowdata, grid+i, h, w)] = 0;
-		    }
-		    do_row(workspace, workspace+max, workspace+2*max,
-			   workspace+3*max, workspace+4*max,
-			   workspace+5*max, workspace+6*max,
-			   matrix+i, h, w, rowdata, changed_h
-#ifdef STANDALONE_SOLVER
-			   , "col", i+1, cluewid
-#endif
-			   );
-		    changed_w[i] = 0;
-		}
-	    }
-	    for (i=0,max_h=0; i<h; i++)
-		if (changed_h[i] > max_h)
-		    max_h = changed_h[i];
-	}
-    } while (max_h>0 || max_w>0);
-
-    ok = TRUE;
-    for (i=0; i<h; i++) {
-	for (j=0; j<w; j++) {
-	    if (matrix[i*w+j] == UNKNOWN)
-		ok = FALSE;
-	}
-    }
-
-    return ok;
-}
-
-#ifndef STANDALONE_PICTURE_GENERATOR
-static unsigned char *generate_soluble(random_state *rs, int w, int h)
-{
-    int i, j, ok, ntries, max;
-    unsigned char *grid, *matrix, *workspace;
-    unsigned int *changed_h, *changed_w;
-    int *rowdata;
-
-    max = max(w, h);
-
-    grid = snewn(w*h, unsigned char);
-    /* Allocate this here, to avoid having to reallocate it again for every geneerated grid */
-    matrix = snewn(w*h, unsigned char);
-    workspace = snewn(max*7, unsigned char);
-    changed_h = snewn(max+1, unsigned int);
-    changed_w = snewn(max+1, unsigned int);
-    rowdata = snewn(max+1, int);
-
-    ntries = 0;
-
-    do {
-        ntries++;
-
-        generate(rs, w, h, grid);
-
-        /*
-         * The game is a bit too easy if any row or column is
-         * completely black or completely white. An exception is
-         * made for rows/columns that are under 3 squares,
-         * otherwise nothing will ever be successfully generated.
-         */
-        ok = TRUE;
-        if (w > 2) {
-            for (i = 0; i < h; i++) {
-                int colours = 0;
-                for (j = 0; j < w; j++)
-                    colours |= (grid[i*w+j] == GRID_FULL ? 2 : 1);
-                if (colours != 3)
-                    ok = FALSE;
-            }
-        }
-        if (h > 2) {
-            for (j = 0; j < w; j++) {
-                int colours = 0;
-                for (i = 0; i < h; i++)
-                    colours |= (grid[i*w+j] == GRID_FULL ? 2 : 1);
-                if (colours != 3)
-                    ok = FALSE;
-            }
-        }
-        if (!ok)
-            continue;
-
-	ok = solve_puzzle(NULL, grid, w, h, matrix, workspace,
-			  changed_h, changed_w, rowdata, 0);
-    } while (!ok);
-
-    sfree(matrix);
-    sfree(workspace);
-    sfree(changed_h);
-    sfree(changed_w);
-    sfree(rowdata);
-    return grid;
-}
-#endif
-
-#ifdef STANDALONE_PICTURE_GENERATOR
-unsigned char *picture;
-#endif
-
-static char *new_game_desc(const game_params *params, random_state *rs,
-			   char **aux, int interactive)
-{
-    unsigned char *grid;
-    int i, j, max, rowlen, *rowdata;
-    char intbuf[80], *desc;
-    int desclen, descpos;
-#ifdef STANDALONE_PICTURE_GENERATOR
-    game_state *state;
-    int *index;
-#endif
-
-    max = max(params->w, params->h);
-
-#ifdef STANDALONE_PICTURE_GENERATOR
-    /*
-     * Fixed input picture.
-     */
-    grid = snewn(params->w * params->h, unsigned char);
-    memcpy(grid, picture, params->w * params->h);
-
-    /*
-     * Now winnow the immutable square set as far as possible.
-     */
-    state = snew(game_state);
-    state->grid = grid;
-    state->common = snew(game_state_common);
-    state->common->rowdata = NULL;
-    state->common->immutable = snewn(params->w * params->h, unsigned char);
-    memset(state->common->immutable, 1, params->w * params->h);
-
-    index = snewn(params->w * params->h, int);
-    for (i = 0; i < params->w * params->h; i++)
-        index[i] = i;
-    shuffle(index, params->w * params->h, sizeof(*index), rs);
-
-    {
-        unsigned char *matrix = snewn(params->w*params->h, unsigned char);
-        unsigned char *workspace = snewn(max*7, unsigned char);
-        unsigned int *changed_h = snewn(max+1, unsigned int);
-        unsigned int *changed_w = snewn(max+1, unsigned int);
-        int *rowdata = snewn(max+1, int);
-        for (i = 0; i < params->w * params->h; i++) {
-            state->common->immutable[index[i]] = 0;
-            if (!solve_puzzle(state, grid, params->w, params->h,
-                              matrix, workspace, changed_h, changed_w,
-                              rowdata, 0))
-                state->common->immutable[index[i]] = 1;
-        }
-        sfree(workspace);
-        sfree(changed_h);
-        sfree(changed_w);
-        sfree(rowdata);
-        sfree(matrix);
-    }
-#else
-    grid = generate_soluble(rs, params->w, params->h);
-#endif
-    rowdata = snewn(max, int);
-
-    /*
-     * Save the solved game in aux.
-     */
-    if (aux) {
-	char *ai = snewn(params->w * params->h + 2, char);
-
-        /*
-         * String format is exactly the same as a solve move, so we
-         * can just dupstr this in solve_game().
-         */
-
-        ai[0] = 'S';
-
-        for (i = 0; i < params->w * params->h; i++)
-            ai[i+1] = grid[i] ? '1' : '0';
-
-        ai[params->w * params->h + 1] = '\0';
-
-	*aux = ai;
-    }
-
-    /*
-     * Seed is a slash-separated list of row contents; each row
-     * contents section is a dot-separated list of integers. Row
-     * contents are listed in the order (columns left to right,
-     * then rows top to bottom).
-     * 
-     * Simplest way to handle memory allocation is to make two
-     * passes, first computing the seed size and then writing it
-     * out.
-     */
-    desclen = 0;
-    for (i = 0; i < params->w + params->h; i++) {
-        if (i < params->w)
-            rowlen = compute_rowdata(rowdata, grid+i, params->h, params->w);
-        else
-            rowlen = compute_rowdata(rowdata, grid+(i-params->w)*params->w,
-                                     params->w, 1);
-        if (rowlen > 0) {
-            for (j = 0; j < rowlen; j++) {
-                desclen += 1 + sprintf(intbuf, "%d", rowdata[j]);
-            }
-        } else {
-            desclen++;
-        }
-    }
-    desc = snewn(desclen, char);
-    descpos = 0;
-    for (i = 0; i < params->w + params->h; i++) {
-        if (i < params->w)
-            rowlen = compute_rowdata(rowdata, grid+i, params->h, params->w);
-        else
-            rowlen = compute_rowdata(rowdata, grid+(i-params->w)*params->w,
-                                     params->w, 1);
-        if (rowlen > 0) {
-            for (j = 0; j < rowlen; j++) {
-                int len = sprintf(desc+descpos, "%d", rowdata[j]);
-                if (j+1 < rowlen)
-                    desc[descpos + len] = '.';
-                else
-                    desc[descpos + len] = '/';
-                descpos += len+1;
-            }
-        } else {
-            desc[descpos++] = '/';
-        }
-    }
-    assert(descpos == desclen);
-    assert(desc[desclen-1] == '/');
-    desc[desclen-1] = '\0';
-#ifdef STANDALONE_PICTURE_GENERATOR
-    for (i = 0; i < params->w * params->h; i++)
-        if (state->common->immutable[i])
-            break;
-    if (i < params->w * params->h) {
-        /*
-         * At least one immutable square, so we need a suffix.
-         */
-        int run;
-
-        desc = sresize(desc, desclen + params->w * params->h + 3, char);
-        desc[descpos-1] = ',';
-
-        run = 0;
-        for (i = 0; i < params->w * params->h; i++) {
-            if (!state->common->immutable[i]) {
-                run++;
-                if (run == 25) {
-                    desc[descpos++] = 'z';
-                    run = 0;
-                }
-            } else {
-                desc[descpos++] = run + (grid[i] == GRID_FULL ? 'A' : 'a');
-                run = 0;
-            }
-        }
-        if (run > 0)
-            desc[descpos++] = run + 'a';
-        desc[descpos] = '\0';
-    }
-    sfree(state->common->immutable);
-    sfree(state->common);
-    sfree(state);
-#endif
-    sfree(rowdata);
-    sfree(grid);
-    return desc;
-}
-
-static char *validate_desc(const game_params *params, const char *desc)
-{
-    int i, n, rowspace;
-    const char *p;
-
-    for (i = 0; i < params->w + params->h; i++) {
-        if (i < params->w)
-            rowspace = params->h + 1;
-        else
-            rowspace = params->w + 1;
-
-        if (*desc && isdigit((unsigned char)*desc)) {
-            do {
-                p = desc;
-                while (*desc && isdigit((unsigned char)*desc)) desc++;
-                n = atoi(p);
-                rowspace -= n+1;
-
-                if (rowspace < 0) {
-                    if (i < params->w)
-                        return "at least one column contains more numbers than will fit";
-                    else
-                        return "at least one row contains more numbers than will fit";
-                }
-            } while (*desc++ == '.');
-        } else {
-            desc++;                    /* expect a slash immediately */
-        }
-
-        if (desc[-1] == '/') {
-            if (i+1 == params->w + params->h)
-                return "too many row/column specifications";
-        } else if (desc[-1] == '\0' || desc[-1] == ',') {
-            if (i+1 < params->w + params->h)
-                return "too few row/column specifications";
-        } else
-            return "unrecognised character in game specification";
-    }
-
-    if (desc[-1] == ',') {
-        /*
-         * Optional extra piece of game description which fills in
-         * some grid squares as extra clues.
-         */
-        i = 0;
-        while (i < params->w * params->h) {
-            int c = (unsigned char)*desc++;
-            if ((c >= 'a' && c <= 'z') ||
-                (c >= 'A' && c <= 'Z')) {
-                int len = tolower(c) - 'a';
-                i += len;
-                if (len < 25 && i < params->w*params->h)
-                    i++;
-                if (i > params->w * params->h) {
-                    return "too much data in clue-squares section";
-                }
-            } else if (!c) {
-                return "too little data in clue-squares section";
-            } else {
-                return "unrecognised character in clue-squares section";
-            }
-        }
-        if (*desc) {
-            return "too much data in clue-squares section";
-        }
-    }
-
-    return NULL;
-}
-
-static game_state *new_game(midend *me, const game_params *params,
-                            const char *desc)
-{
-    int i;
-    const char *p;
-    game_state *state = snew(game_state);
-
-    state->common = snew(game_state_common);
-    state->common->refcount = 1;
-
-    state->common->w = params->w;
-    state->common->h = params->h;
-
-    state->grid = snewn(state->common->w * state->common->h, unsigned char);
-    memset(state->grid, GRID_UNKNOWN, state->common->w * state->common->h);
-
-    state->common->immutable = snewn(state->common->w * state->common->h,
-                                     unsigned char);
-    memset(state->common->immutable, 0, state->common->w * state->common->h);
-
-    state->common->rowsize = max(state->common->w, state->common->h);
-    state->common->rowdata = snewn(state->common->rowsize * (state->common->w + state->common->h), int);
-    state->common->rowlen = snewn(state->common->w + state->common->h, int);
-
-    state->completed = state->cheated = FALSE;
-
-    for (i = 0; i < params->w + params->h; i++) {
-        state->common->rowlen[i] = 0;
-        if (*desc && isdigit((unsigned char)*desc)) {
-            do {
-                p = desc;
-                while (*desc && isdigit((unsigned char)*desc)) desc++;
-                state->common->rowdata[state->common->rowsize * i + state->common->rowlen[i]++] =
-                    atoi(p);
-            } while (*desc++ == '.');
-        } else {
-            desc++;                    /* expect a slash immediately */
-        }
-    }
-
-    if (desc[-1] == ',') {
-        /*
-         * Optional extra piece of game description which fills in
-         * some grid squares as extra clues.
-         */
-        i = 0;
-        while (i < params->w * params->h) {
-            int c = (unsigned char)*desc++;
-            int full = isupper(c), len = tolower(c) - 'a';
-            i += len;
-            if (len < 25 && i < params->w*params->h) {
-                state->grid[i] = full ? GRID_FULL : GRID_EMPTY;
-                state->common->immutable[i] = TRUE;
-                i++;
-            }
-        }
-    }
-
-    return state;
-}
-
-static game_state *dup_game(const game_state *state)
-{
-    game_state *ret = snew(game_state);
-
-    ret->common = state->common;
-    ret->common->refcount++;
-
-    ret->grid = snewn(ret->common->w * ret->common->h, unsigned char);
-    memcpy(ret->grid, state->grid, ret->common->w * ret->common->h);
-
-    ret->completed = state->completed;
-    ret->cheated = state->cheated;
-
-    return ret;
-}
-
-static void free_game(game_state *state)
-{
-    if (--state->common->refcount == 0) {
-        sfree(state->common->rowdata);
-        sfree(state->common->rowlen);
-        sfree(state->common->immutable);
-        sfree(state->common);
-    }
-    sfree(state->grid);
-    sfree(state);
-}
-
-static char *solve_game(const game_state *state, const game_state *currstate,
-                        const char *ai, char **error)
-{
-    unsigned char *matrix;
-    int w = state->common->w, h = state->common->h;
-    int i;
-    char *ret;
-    int max, ok;
-    unsigned char *workspace;
-    unsigned int *changed_h, *changed_w;
-    int *rowdata;
-
-    /*
-     * If we already have the solved state in ai, copy it out.
-     */
-    if (ai)
-        return dupstr(ai);
-
-    max = max(w, h);
-    matrix = snewn(w*h, unsigned char);
-    workspace = snewn(max*7, unsigned char);
-    changed_h = snewn(max+1, unsigned int);
-    changed_w = snewn(max+1, unsigned int);
-    rowdata = snewn(max+1, int);
-
-    ok = solve_puzzle(state, NULL, w, h, matrix, workspace,
-		      changed_h, changed_w, rowdata, 0);
-
-    sfree(workspace);
-    sfree(changed_h);
-    sfree(changed_w);
-    sfree(rowdata);
-
-    if (!ok) {
-	sfree(matrix);
-	*error = "Solving algorithm cannot complete this puzzle";
-	return NULL;
-    }
-
-    ret = snewn(w*h+2, char);
-    ret[0] = 'S';
-    for (i = 0; i < w*h; i++) {
-	assert(matrix[i] == BLOCK || matrix[i] == DOT);
-	ret[i+1] = (matrix[i] == BLOCK ? '1' : '0');
-    }
-    ret[w*h+1] = '\0';
-
-    sfree(matrix);
-
-    return ret;
-}
-
-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->common->w, h = state->common->h, i, j;
-    int left_gap = 0, top_gap = 0, ch = 2, cw = 1, limit = 1;
-
-    int len, topleft, lw, lh, gw, gh; /* {line,grid}_{width,height} */
-    char *board, *buf;
-
-    for (i = 0; i < w; ++i) {
-	top_gap = max(top_gap, state->common->rowlen[i]);
-	for (j = 0; j < state->common->rowlen[i]; ++j)
-	    while (state->common->rowdata[i*state->common->rowsize + j] >= limit) {
-		++cw;
-		limit *= 10;
-	    }
-    }
-    for (i = 0; i < h; ++i) {
-	int rowlen = 0, predecessors = FALSE;
-	for (j = 0; j < state->common->rowlen[i+w]; ++j) {
-	    int copy = state->common->rowdata[(i+w)*state->common->rowsize + j];
-	    rowlen += predecessors;
-	    predecessors = TRUE;
-	    do ++rowlen; while (copy /= 10);
-	}
-	left_gap = max(left_gap, rowlen);
-    }
-
-    cw = max(cw, 3);
-
-    gw = w*cw + 2;
-    gh = h*ch + 1;
-    lw = gw + left_gap;
-    lh = gh + top_gap;
-    len = lw * lh;
-    topleft = lw * top_gap + left_gap;
-
-    board = snewn(len + 1, char);
-    sprintf(board, "%*s\n", len - 2, "");
-
-    for (i = 0; i < lh; ++i) {
-	board[lw - 1 + i*lw] = '\n';
-	if (i < top_gap) continue;
-	board[lw - 2 + i*lw] = ((i - top_gap) % ch ? '|' : '+');
-    }
-
-    for (i = 0; i < w; ++i) {
-	for (j = 0; j < state->common->rowlen[i]; ++j) {
-	    int cell = topleft + i*cw + 1 + lw*(j - state->common->rowlen[i]);
-	    int nch = sprintf(board + cell, "%*d", cw - 1,
-			      state->common->rowdata[i*state->common->rowsize + j]);
-	    board[cell + nch] = ' '; /* de-NUL-ify */
-	}
-    }
-
-    buf = snewn(left_gap, char);
-    for (i = 0; i < h; ++i) {
-	char *p = buf, *start = board + top_gap*lw + left_gap + (i*ch+1)*lw;
-	for (j = 0; j < state->common->rowlen[i+w]; ++j) {
-	    if (p > buf) *p++ = ' ';
-	    p += sprintf(p, "%d", state->common->rowdata[(i+w)*state->common->rowsize + j]);
-	}
-	memcpy(start - (p - buf), buf, p - buf);
-    }
-
-    for (i = 0; i < w; ++i) {
-	for (j = 0; j < h; ++j) {
-	    int cell = topleft + i*cw + j*ch*lw;
-	    int center = cell + cw/2 + (ch/2)*lw;
-	    int dx, dy;
-	    board[cell] = 0 ? center : '+';
-	    for (dx = 1; dx < cw; ++dx) board[cell + dx] = '-';
-	    for (dy = 1; dy < ch; ++dy) board[cell + dy*lw] = '|';
-	    if (state->grid[i*w+j] == GRID_UNKNOWN) continue;
-	    for (dx = 1; dx < cw; ++dx)
-		for (dy = 1; dy < ch; ++dy)
-		    board[cell + dx + dy*lw] =
-			state->grid[i*w+j] == GRID_FULL ? '#' : '.';
-	}
-    }
-
-    memcpy(board + topleft + h*ch*lw, board + topleft, gw - 1);
-
-    sfree(buf);
-
-    return board;
-}
-
-struct game_ui {
-    int dragging;
-    int drag_start_x;
-    int drag_start_y;
-    int drag_end_x;
-    int drag_end_y;
-    int drag, release, state;
-    int cur_x, cur_y, cur_visible;
-};
-
-static game_ui *new_ui(const game_state *state)
-{
-    game_ui *ret;
-
-    ret = snew(game_ui);
-    ret->dragging = FALSE;
-    ret->cur_x = ret->cur_y = ret->cur_visible = 0;
-
-    return ret;
-}
-
-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)
-{
-}
-
-static void game_changed_state(game_ui *ui, const game_state *oldstate,
-                               const game_state *newstate)
-{
-}
-
-struct game_drawstate {
-    int started;
-    int w, h;
-    int tilesize;
-    unsigned char *visible, *numcolours;
-    int cur_x, cur_y;
-};
-
-static char *interpret_move(const game_state *state, game_ui *ui,
-                            const game_drawstate *ds,
-                            int x, int y, int button)
-{
-    int control = button & MOD_CTRL, shift = button & MOD_SHFT;
-    button &= ~MOD_MASK;
-
-    x = FROMCOORD(state->common->w, x);
-    y = FROMCOORD(state->common->h, y);
-
-    if (x >= 0 && x < state->common->w && y >= 0 && y < state->common->h &&
-        (button == LEFT_BUTTON || button == RIGHT_BUTTON ||
-         button == MIDDLE_BUTTON)) {
-#ifdef STYLUS_BASED
-        int currstate = state->grid[y * state->common->w + x];
-#endif
-
-        ui->dragging = TRUE;
-
-        if (button == LEFT_BUTTON) {
-            ui->drag = LEFT_DRAG;
-            ui->release = LEFT_RELEASE;
-#ifdef STYLUS_BASED
-            ui->state = (currstate + 2) % 3; /* FULL -> EMPTY -> UNKNOWN */
-#else
-            ui->state = GRID_FULL;
-#endif
-        } else if (button == RIGHT_BUTTON) {
-            ui->drag = RIGHT_DRAG;
-            ui->release = RIGHT_RELEASE;
-#ifdef STYLUS_BASED
-            ui->state = (currstate + 1) % 3; /* EMPTY -> FULL -> UNKNOWN */
-#else
-            ui->state = GRID_EMPTY;
-#endif
-        } else /* if (button == MIDDLE_BUTTON) */ {
-            ui->drag = MIDDLE_DRAG;
-            ui->release = MIDDLE_RELEASE;
-            ui->state = GRID_UNKNOWN;
-        }
-
-        ui->drag_start_x = ui->drag_end_x = x;
-        ui->drag_start_y = ui->drag_end_y = y;
-        ui->cur_visible = 0;
-
-        return "";		       /* UI activity occurred */
-    }
-
-    if (ui->dragging && button == ui->drag) {
-        /*
-         * There doesn't seem much point in allowing a rectangle
-         * drag; people will generally only want to drag a single
-         * horizontal or vertical line, so we make that easy by
-         * snapping to it.
-         * 
-         * Exception: if we're _middle_-button dragging to tag
-         * things as UNKNOWN, we may well want to trash an entire
-         * area and start over!
-         */
-        if (ui->state != GRID_UNKNOWN) {
-            if (abs(x - ui->drag_start_x) > abs(y - ui->drag_start_y))
-                y = ui->drag_start_y;
-            else
-                x = ui->drag_start_x;
-        }
-
-        if (x < 0) x = 0;
-        if (y < 0) y = 0;
-        if (x >= state->common->w) x = state->common->w - 1;
-        if (y >= state->common->h) y = state->common->h - 1;
-
-        ui->drag_end_x = x;
-        ui->drag_end_y = y;
-
-        return "";		       /* UI activity occurred */
-    }
-
-    if (ui->dragging && button == ui->release) {
-        int x1, x2, y1, y2, xx, yy;
-        int move_needed = FALSE;
-
-        x1 = min(ui->drag_start_x, ui->drag_end_x);
-        x2 = max(ui->drag_start_x, ui->drag_end_x);
-        y1 = min(ui->drag_start_y, ui->drag_end_y);
-        y2 = max(ui->drag_start_y, ui->drag_end_y);
-
-        for (yy = y1; yy <= y2; yy++)
-            for (xx = x1; xx <= x2; xx++)
-                if (!state->common->immutable[yy * state->common->w + xx] &&
-                    state->grid[yy * state->common->w + xx] != ui->state)
-                    move_needed = TRUE;
-
-        ui->dragging = FALSE;
-
-        if (move_needed) {
-	    char buf[80];
-	    sprintf(buf, "%c%d,%d,%d,%d",
-		    (char)(ui->state == GRID_FULL ? 'F' :
-		           ui->state == GRID_EMPTY ? 'E' : 'U'),
-		    x1, y1, x2-x1+1, y2-y1+1);
-	    return dupstr(buf);
-        } else
-            return "";		       /* UI activity occurred */
-    }
-
-    if (IS_CURSOR_MOVE(button)) {
-	int x = ui->cur_x, y = ui->cur_y, newstate;
-	char buf[80];
-        move_cursor(button, &ui->cur_x, &ui->cur_y, state->common->w, state->common->h, 0);
-        ui->cur_visible = 1;
-	if (!control && !shift) return "";
-
-	newstate = control ? shift ? GRID_UNKNOWN : GRID_FULL : GRID_EMPTY;
-	if (state->grid[y * state->common->w + x] == newstate &&
-	    state->grid[ui->cur_y * state->common->w + ui->cur_x] == newstate)
-	    return "";
-
-	sprintf(buf, "%c%d,%d,%d,%d", control ? shift ? 'U' : 'F' : 'E',
-		min(x, ui->cur_x), min(y, ui->cur_y),
-		abs(x - ui->cur_x) + 1, abs(y - ui->cur_y) + 1);
-	return dupstr(buf);
-    }
-
-    if (IS_CURSOR_SELECT(button)) {
-        int currstate = state->grid[ui->cur_y * state->common->w + ui->cur_x];
-        int newstate;
-        char buf[80];
-
-        if (!ui->cur_visible) {
-            ui->cur_visible = 1;
-            return "";
-        }
-
-        if (button == CURSOR_SELECT2)
-            newstate = currstate == GRID_UNKNOWN ? GRID_EMPTY :
-                currstate == GRID_EMPTY ? GRID_FULL : GRID_UNKNOWN;
-        else
-            newstate = currstate == GRID_UNKNOWN ? GRID_FULL :
-                currstate == GRID_FULL ? GRID_EMPTY : GRID_UNKNOWN;
-
-        sprintf(buf, "%c%d,%d,%d,%d",
-                (char)(newstate == GRID_FULL ? 'F' :
-		       newstate == GRID_EMPTY ? 'E' : 'U'),
-                ui->cur_x, ui->cur_y, 1, 1);
-        return dupstr(buf);
-    }
-
-    return NULL;
-}
-
-static game_state *execute_move(const game_state *from, const char *move)
-{
-    game_state *ret;
-    int x1, x2, y1, y2, xx, yy;
-    int val;
-
-    if (move[0] == 'S' &&
-        strlen(move) == from->common->w * from->common->h + 1) {
-	int i;
-
-	ret = dup_game(from);
-
-	for (i = 0; i < ret->common->w * ret->common->h; i++)
-	    ret->grid[i] = (move[i+1] == '1' ? GRID_FULL : GRID_EMPTY);
-
-	ret->completed = ret->cheated = TRUE;
-
-	return ret;
-    } else if ((move[0] == 'F' || move[0] == 'E' || move[0] == 'U') &&
-	sscanf(move+1, "%d,%d,%d,%d", &x1, &y1, &x2, &y2) == 4 &&
-	x1 >= 0 && x2 >= 0 && x1+x2 <= from->common->w &&
-	y1 >= 0 && y2 >= 0 && y1+y2 <= from->common->h) {
-
-	x2 += x1;
-	y2 += y1;
-	val = (move[0] == 'F' ? GRID_FULL :
-		 move[0] == 'E' ? GRID_EMPTY : GRID_UNKNOWN);
-
-	ret = dup_game(from);
-	for (yy = y1; yy < y2; yy++)
-	    for (xx = x1; xx < x2; xx++)
-                if (!ret->common->immutable[yy * ret->common->w + xx])
-                    ret->grid[yy * ret->common->w + xx] = val;
-
-	/*
-	 * An actual change, so check to see if we've completed the
-	 * game.
-	 */
-	if (!ret->completed) {
-	    int *rowdata = snewn(ret->common->rowsize, int);
-	    int i, len;
-
-	    ret->completed = TRUE;
-
-	    for (i=0; i<ret->common->w; i++) {
-		len = compute_rowdata(rowdata, ret->grid+i,
-                                      ret->common->h, ret->common->w);
-		if (len != ret->common->rowlen[i] ||
-		    memcmp(ret->common->rowdata+i*ret->common->rowsize,
-                           rowdata, len * sizeof(int))) {
-		    ret->completed = FALSE;
-		    break;
-		}
-	    }
-	    for (i=0; i<ret->common->h; i++) {
-		len = compute_rowdata(rowdata, ret->grid+i*ret->common->w,
-                                      ret->common->w, 1);
-		if (len != ret->common->rowlen[i+ret->common->w] ||
-		    memcmp(ret->common->rowdata +
-                           (i+ret->common->w)*ret->common->rowsize,
-                           rowdata, len * sizeof(int))) {
-		    ret->completed = FALSE;
-		    break;
-		}
-	    }
-
-	    sfree(rowdata);
-	}
-
-	return ret;
-    } else
-	return NULL;
-}
-
-/* ----------------------------------------------------------------------
- * Error-checking during gameplay.
- */
-
-/*
- * The difficulty in error-checking Pattern is to make the error check
- * _weak_ enough. The most obvious way would be to check each row and
- * column by calling (a modified form of) do_row() to recursively
- * analyse the row contents against the clue set and see if the
- * GRID_UNKNOWNs could be filled in in any way that would end up
- * correct. However, this turns out to be such a strong error check as
- * to constitute a spoiler in many situations: you make a typo while
- * trying to fill in one row, and not only does the row light up to
- * indicate an error, but several columns crossed by the move also
- * light up and draw your attention to deductions you hadn't even
- * noticed you could make.
- *
- * So instead I restrict error-checking to 'complete runs' within a
- * row, by which I mean contiguous sequences of GRID_FULL bounded at
- * both ends by either GRID_EMPTY or the ends of the row. We identify
- * all the complete runs in a row, and verify that _those_ are
- * consistent with the row's clue list. Sequences of complete runs
- * separated by solid GRID_EMPTY are required to match contiguous
- * sequences in the clue list, whereas if there's at least one
- * GRID_UNKNOWN between any two complete runs then those two need not
- * be contiguous in the clue list.
- *
- * To simplify the edge cases, I pretend that the clue list for the
- * row is extended with a 0 at each end, and I also pretend that the
- * grid data for the row is extended with a GRID_EMPTY and a
- * zero-length run at each end. This permits the contiguity checker to
- * handle the fiddly end effects (e.g. if the first contiguous
- * sequence of complete runs in the grid matches _something_ in the
- * clue list but not at the beginning, this is allowable iff there's a
- * GRID_UNKNOWN before the first one) with minimal faff, since the end
- * effects just drop out as special cases of the normal inter-run
- * handling (in this code the above case is not 'at the end of the
- * clue list' at all, but between the implicit initial zero run and
- * the first nonzero one).
- *
- * We must also be a little careful about how we search for a
- * contiguous sequence of runs. In the clue list (1 1 2 1 2 3),
- * suppose we see a GRID_UNKNOWN and then a length-1 run. We search
- * for 1 in the clue list and find it at the very beginning. But now
- * suppose we find a length-2 run with no GRID_UNKNOWN before it. We
- * can't naively look at the next clue from the 1 we found, because
- * that'll be the second 1 and won't match. Instead, we must backtrack
- * by observing that the 2 we've just found must be contiguous with
- * the 1 we've already seen, so we search for the sequence (1 2) and
- * find it starting at the second 1. Now if we see a 3, we must
- * rethink again and search for (1 2 3).
- */
-
-struct errcheck_state {
-    /*
-     * rowdata and rowlen point at the clue data for this row in the
-     * game state.
-     */
-    int *rowdata;
-    int rowlen;
-    /*
-     * rowpos indicates the lowest position where it would be valid to
-     * see our next run length. It might be equal to rowlen,
-     * indicating that the next run would have to be the terminating 0.
-     */
-    int rowpos;
-    /*
-     * ncontig indicates how many runs we've seen in a contiguous
-     * block. This is taken into account when searching for the next
-     * run we find, unless ncontig is zeroed out first by encountering
-     * a GRID_UNKNOWN.
-     */
-    int ncontig;
-};
-
-static int errcheck_found_run(struct errcheck_state *es, int r)
-{
-/* Macro to handle the pretence that rowdata has a 0 at each end */
-#define ROWDATA(k) ((k)<0 || (k)>=es->rowlen ? 0 : es->rowdata[(k)])
-
-    /*
-     * See if we can find this new run length at a position where it
-     * also matches the last 'ncontig' runs we've seen.
-     */
-    int i, newpos;
-    for (newpos = es->rowpos; newpos <= es->rowlen; newpos++) {
-
-        if (ROWDATA(newpos) != r)
-            goto notfound;
-
-        for (i = 1; i <= es->ncontig; i++)
-            if (ROWDATA(newpos - i) != ROWDATA(es->rowpos - i))
-                goto notfound;
-
-        es->rowpos = newpos+1;
-        es->ncontig++;
-        return TRUE;
-
-      notfound:;
-    }
-
-    return FALSE;
-
-#undef ROWDATA
-}
-
-static int check_errors(const game_state *state, int i)
-{
-    int start, step, end, j;
-    int val, runlen;
-    struct errcheck_state aes, *es = &aes;
-
-    es->rowlen = state->common->rowlen[i];
-    es->rowdata = state->common->rowdata + state->common->rowsize * i;
-    /* Pretend that we've already encountered the initial zero run */
-    es->ncontig = 1;
-    es->rowpos = 0;
-
-    if (i < state->common->w) {
-        start = i;
-        step = state->common->w;
-        end = start + step * state->common->h;
-    } else {
-        start = (i - state->common->w) * state->common->w;
-        step = 1;
-        end = start + step * state->common->w;
-    }
-
-    runlen = -1;
-    for (j = start - step; j <= end; j += step) {
-        if (j < start || j == end)
-            val = GRID_EMPTY;
-        else
-            val = state->grid[j];
-
-        if (val == GRID_UNKNOWN) {
-            runlen = -1;
-            es->ncontig = 0;
-        } else if (val == GRID_FULL) {
-            if (runlen >= 0)
-                runlen++;
-        } else if (val == GRID_EMPTY) {
-            if (runlen > 0) {
-                if (!errcheck_found_run(es, runlen))
-                    return TRUE;       /* error! */
-            }
-            runlen = 0;
-        }
-    }
-
-    /* Signal end-of-row by sending errcheck_found_run the terminating
-     * zero run, which will be marked as contiguous with the previous
-     * run if and only if there hasn't been a GRID_UNKNOWN before. */
-    if (!errcheck_found_run(es, 0))
-        return TRUE;                   /* error at the last minute! */
-
-    return FALSE;                      /* no error */
-}
-
-/* ----------------------------------------------------------------------
- * Drawing routines.
- */
-
-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 = SIZE(params->w);
-    *y = SIZE(params->h);
-}
-
-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 = snewn(3 * NCOLOURS, float);
-    int i;
-
-    frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
-
-    for (i = 0; i < 3; i++) {
-        ret[COL_GRID    * 3 + i] = 0.3F;
-        ret[COL_UNKNOWN * 3 + i] = 0.5F;
-        ret[COL_TEXT    * 3 + i] = 0.0F;
-        ret[COL_FULL    * 3 + i] = 0.0F;
-        ret[COL_EMPTY   * 3 + i] = 1.0F;
-    }
-    ret[COL_CURSOR * 3 + 0] = 1.0F;
-    ret[COL_CURSOR * 3 + 1] = 0.25F;
-    ret[COL_CURSOR * 3 + 2] = 0.25F;
-    ret[COL_ERROR * 3 + 0] = 1.0F;
-    ret[COL_ERROR * 3 + 1] = 0.0F;
-    ret[COL_ERROR * 3 + 2] = 0.0F;
-
-    *ncolours = NCOLOURS;
-    return ret;
-}
-
-static game_drawstate *game_new_drawstate(drawing *dr, const game_state *state)
-{
-    struct game_drawstate *ds = snew(struct game_drawstate);
-
-    ds->started = FALSE;
-    ds->w = state->common->w;
-    ds->h = state->common->h;
-    ds->visible = snewn(ds->w * ds->h, unsigned char);
-    ds->tilesize = 0;                  /* not decided yet */
-    memset(ds->visible, 255, ds->w * ds->h);
-    ds->numcolours = snewn(ds->w + ds->h, unsigned char);
-    memset(ds->numcolours, 255, ds->w + ds->h);
-    ds->cur_x = ds->cur_y = 0;
-
-    return ds;
-}
-
-static void game_free_drawstate(drawing *dr, game_drawstate *ds)
-{
-    sfree(ds->visible);
-    sfree(ds);
-}
-
-static void grid_square(drawing *dr, game_drawstate *ds,
-                        int y, int x, int state, int cur)
-{
-    int xl, xr, yt, yb, dx, dy, dw, dh;
-
-    draw_rect(dr, TOCOORD(ds->w, x), TOCOORD(ds->h, y),
-              TILE_SIZE, TILE_SIZE, COL_GRID);
-
-    xl = (x % 5 == 0 ? 1 : 0);
-    yt = (y % 5 == 0 ? 1 : 0);
-    xr = (x % 5 == 4 || x == ds->w-1 ? 1 : 0);
-    yb = (y % 5 == 4 || y == ds->h-1 ? 1 : 0);
-
-    dx = TOCOORD(ds->w, x) + 1 + xl;
-    dy = TOCOORD(ds->h, y) + 1 + yt;
-    dw = TILE_SIZE - xl - xr - 1;
-    dh = TILE_SIZE - yt - yb - 1;
-
-    draw_rect(dr, dx, dy, dw, dh,
-              (state == GRID_FULL ? COL_FULL :
-               state == GRID_EMPTY ? COL_EMPTY : COL_UNKNOWN));
-    if (cur) {
-        draw_rect_outline(dr, dx, dy, dw, dh, COL_CURSOR);
-        draw_rect_outline(dr, dx+1, dy+1, dw-2, dh-2, COL_CURSOR);
-    }
-
-    draw_update(dr, TOCOORD(ds->w, x), TOCOORD(ds->h, y),
-                TILE_SIZE, TILE_SIZE);
-}
-
-/*
- * Draw the numbers for a single row or column.
- */
-static void draw_numbers(drawing *dr, game_drawstate *ds,
-                         const game_state *state, int i, int erase, int colour)
-{
-    int rowlen = state->common->rowlen[i];
-    int *rowdata = state->common->rowdata + state->common->rowsize * i;
-    int nfit;
-    int j;
-
-    if (erase) {
-        if (i < state->common->w) {
-            draw_rect(dr, TOCOORD(state->common->w, i), 0,
-                      TILE_SIZE, BORDER + TLBORDER(state->common->h) * TILE_SIZE,
-                      COL_BACKGROUND);
-        } else {
-            draw_rect(dr, 0, TOCOORD(state->common->h, i - state->common->w),
-                      BORDER + TLBORDER(state->common->w) * TILE_SIZE, TILE_SIZE,
-                      COL_BACKGROUND);
-        }
-    }
-
-    /*
-     * Normally I space the numbers out by the same distance as the
-     * tile size. However, if there are more numbers than available
-     * spaces, I have to squash them up a bit.
-     */
-    if (i < state->common->w)
-        nfit = TLBORDER(state->common->h);
-    else
-        nfit = TLBORDER(state->common->w);
-    nfit = max(rowlen, nfit) - 1;
-    assert(nfit > 0);
-
-    for (j = 0; j < rowlen; j++) {
-        int x, y;
-        char str[80];
-
-        if (i < state->common->w) {
-            x = TOCOORD(state->common->w, i);
-            y = BORDER + TILE_SIZE * (TLBORDER(state->common->h)-1);
-            y -= ((rowlen-j-1)*TILE_SIZE) * (TLBORDER(state->common->h)-1) / nfit;
-        } else {
-            y = TOCOORD(state->common->h, i - state->common->w);
-            x = BORDER + TILE_SIZE * (TLBORDER(state->common->w)-1);
-            x -= ((rowlen-j-1)*TILE_SIZE) * (TLBORDER(state->common->w)-1) / nfit;
-        }
-
-        sprintf(str, "%d", rowdata[j]);
-        draw_text(dr, x+TILE_SIZE/2, y+TILE_SIZE/2, FONT_VARIABLE,
-                  TILE_SIZE/2, ALIGN_HCENTRE | ALIGN_VCENTRE, colour, str);
-    }
-
-    if (i < state->common->w) {
-        draw_update(dr, TOCOORD(state->common->w, i), 0,
-                    TILE_SIZE, BORDER + TLBORDER(state->common->h) * TILE_SIZE);
-    } else {
-        draw_update(dr, 0, TOCOORD(state->common->h, i - state->common->w),
-                    BORDER + TLBORDER(state->common->w) * TILE_SIZE, TILE_SIZE);
-    }
-}
-
-static void game_redraw(drawing *dr, game_drawstate *ds,
-                        const game_state *oldstate, const game_state *state,
-                        int dir, const game_ui *ui,
-                        float animtime, float flashtime)
-{
-    int i, j;
-    int x1, x2, y1, y2;
-    int cx, cy, cmoved;
-
-    if (!ds->started) {
-        /*
-         * The initial contents of the window are not guaranteed
-         * and can vary with front ends. To be on the safe side,
-         * all games should start by drawing a big background-
-         * colour rectangle covering the whole window.
-         */
-        draw_rect(dr, 0, 0, SIZE(ds->w), SIZE(ds->h), COL_BACKGROUND);
-
-        /*
-         * Draw the grid outline.
-         */
-        draw_rect(dr, TOCOORD(ds->w, 0) - 1, TOCOORD(ds->h, 0) - 1,
-                  ds->w * TILE_SIZE + 3, ds->h * TILE_SIZE + 3,
-                  COL_GRID);
-
-        ds->started = TRUE;
-
-	draw_update(dr, 0, 0, SIZE(ds->w), SIZE(ds->h));
-    }
-
-    if (ui->dragging) {
-        x1 = min(ui->drag_start_x, ui->drag_end_x);
-        x2 = max(ui->drag_start_x, ui->drag_end_x);
-        y1 = min(ui->drag_start_y, ui->drag_end_y);
-        y2 = max(ui->drag_start_y, ui->drag_end_y);
-    } else {
-        x1 = x2 = y1 = y2 = -1;        /* placate gcc warnings */
-    }
-
-    if (ui->cur_visible) {
-        cx = ui->cur_x; cy = ui->cur_y;
-    } else {
-        cx = cy = -1;
-    }
-    cmoved = (cx != ds->cur_x || cy != ds->cur_y);
-
-    /*
-     * Now draw any grid squares which have changed since last
-     * redraw.
-     */
-    for (i = 0; i < ds->h; i++) {
-        for (j = 0; j < ds->w; j++) {
-            int val, cc = 0;
-
-            /*
-             * Work out what state this square should be drawn in,
-             * taking any current drag operation into account.
-             */
-            if (ui->dragging && x1 <= j && j <= x2 && y1 <= i && i <= y2 &&
-                !state->common->immutable[i * state->common->w + j])
-                val = ui->state;
-            else
-                val = state->grid[i * state->common->w + j];
-
-            if (cmoved) {
-                /* the cursor has moved; if we were the old or
-                 * the new cursor position we need to redraw. */
-                if (j == cx && i == cy) cc = 1;
-                if (j == ds->cur_x && i == ds->cur_y) cc = 1;
-            }
-
-            /*
-             * Briefly invert everything twice during a completion
-             * flash.
-             */
-            if (flashtime > 0 &&
-                (flashtime <= FLASH_TIME/3 || flashtime >= FLASH_TIME*2/3) &&
-                val != GRID_UNKNOWN)
-                val = (GRID_FULL ^ GRID_EMPTY) ^ val;
-
-            if (ds->visible[i * ds->w + j] != val || cc) {
-                grid_square(dr, ds, i, j, val,
-                            (j == cx && i == cy));
-                ds->visible[i * ds->w + j] = val;
-            }
-        }
-    }
-    ds->cur_x = cx; ds->cur_y = cy;
-
-    /*
-     * Redraw any numbers which have changed their colour due to error
-     * indication.
-     */
-    for (i = 0; i < state->common->w + state->common->h; i++) {
-        int colour = check_errors(state, i) ? COL_ERROR : COL_TEXT;
-        if (ds->numcolours[i] != colour) {
-            draw_numbers(dr, ds, state, i, TRUE, colour);
-            ds->numcolours[i] = colour;
-        }
-    }
-}
-
-static float game_anim_length(const game_state *oldstate,
-                              const game_state *newstate, int dir, game_ui *ui)
-{
-    return 0.0F;
-}
-
-static float game_flash_length(const game_state *oldstate,
-                               const game_state *newstate, int dir, game_ui *ui)
-{
-    if (!oldstate->completed && newstate->completed &&
-	!oldstate->cheated && !newstate->cheated)
-        return FLASH_TIME;
-    return 0.0F;
-}
-
-static int game_status(const game_state *state)
-{
-    return state->completed ? +1 : 0;
-}
-
-static int game_timing_state(const game_state *state, game_ui *ui)
-{
-    return TRUE;
-}
-
-static void game_print_size(const game_params *params, float *x, float *y)
-{
-    int pw, ph;
-
-    /*
-     * I'll use 5mm squares by default.
-     */
-    game_compute_size(params, 500, &pw, &ph);
-    *x = pw / 100.0F;
-    *y = ph / 100.0F;
-}
-
-static void game_print(drawing *dr, const game_state *state, int tilesize)
-{
-    int w = state->common->w, h = state->common->h;
-    int ink = print_mono_colour(dr, 0);
-    int x, y, i;
-
-    /* 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 / 16);
-    draw_rect_outline(dr, TOCOORD(w, 0), TOCOORD(h, 0),
-		      w*TILE_SIZE, h*TILE_SIZE, ink);
-
-    /*
-     * Grid.
-     */
-    for (x = 1; x < w; x++) {
-	print_line_width(dr, TILE_SIZE / (x % 5 ? 128 : 24));
-	draw_line(dr, TOCOORD(w, x), TOCOORD(h, 0),
-		  TOCOORD(w, x), TOCOORD(h, h), ink);
-    }
-    for (y = 1; y < h; y++) {
-	print_line_width(dr, TILE_SIZE / (y % 5 ? 128 : 24));
-	draw_line(dr, TOCOORD(w, 0), TOCOORD(h, y),
-		  TOCOORD(w, w), TOCOORD(h, y), ink);
-    }
-
-    /*
-     * Clues.
-     */
-    for (i = 0; i < state->common->w + state->common->h; i++)
-        draw_numbers(dr, ds, state, i, FALSE, ink);
-
-    /*
-     * Solution.
-     */
-    print_line_width(dr, TILE_SIZE / 128);
-    for (y = 0; y < h; y++)
-	for (x = 0; x < w; x++) {
-	    if (state->grid[y*w+x] == GRID_FULL)
-		draw_rect(dr, TOCOORD(w, x), TOCOORD(h, y),
-			  TILE_SIZE, TILE_SIZE, ink);
-	    else if (state->grid[y*w+x] == GRID_EMPTY)
-		draw_circle(dr, TOCOORD(w, x) + TILE_SIZE/2,
-			    TOCOORD(h, y) + TILE_SIZE/2,
-			    TILE_SIZE/12, ink, ink);
-	}
-}
-
-#ifdef COMBINED
-#define thegame pattern
-#endif
-
-const struct game thegame = {
-    "Pattern", "games.pattern", "pattern",
-    default_params,
-    game_fetch_preset,
-    decode_params,
-    encode_params,
-    free_params,
-    dup_params,
-    TRUE, game_configure, custom_params,
-    validate_params,
-    new_game_desc,
-    validate_desc,
-    new_game,
-    dup_game,
-    free_game,
-    TRUE, solve_game,
-    TRUE, game_can_format_as_text_now, game_text_format,
-    new_ui,
-    free_ui,
-    encode_ui,
-    decode_ui,
-    game_changed_state,
-    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_status,
-    TRUE, FALSE, game_print_size, game_print,
-    FALSE,			       /* wants_statusbar */
-    FALSE, game_timing_state,
-    REQUIRE_RBUTTON,		       /* flags */
-};
-
-#ifdef STANDALONE_SOLVER
-
-int main(int argc, char **argv)
-{
-    game_params *p;
-    game_state *s;
-    char *id = NULL, *desc, *err;
-
-    while (--argc > 0) {
-        char *p = *++argv;
-	if (*p == '-') {
-	    if (!strcmp(p, "-v")) {
-		verbose = TRUE;
-	    } else {
-		fprintf(stderr, "%s: unrecognised option `%s'\n", argv[0], p);
-		return 1;
-	    }
-        } else {
-            id = p;
-        }
-    }
-
-    if (!id) {
-        fprintf(stderr, "usage: %s <game_id>\n", argv[0]);
-        return 1;
-    }
-
-    desc = strchr(id, ':');
-    if (!desc) {
-        fprintf(stderr, "%s: game id expects a colon in it\n", argv[0]);
-        return 1;
-    }
-    *desc++ = '\0';
-
-    p = default_params();
-    decode_params(p, id);
-    err = validate_desc(p, desc);
-    if (err) {
-        fprintf(stderr, "%s: %s\n", argv[0], err);
-        return 1;
-    }
-    s = new_game(NULL, p, desc);
-
-    {
-	int w = p->w, h = p->h, i, j, max, cluewid = 0;
-	unsigned char *matrix, *workspace;
-	unsigned int *changed_h, *changed_w;
-	int *rowdata;
-
-	matrix = snewn(w*h, unsigned char);
-	max = max(w, h);
-	workspace = snewn(max*7, unsigned char);
-	changed_h = snewn(max+1, unsigned int);
-	changed_w = snewn(max+1, unsigned int);
-	rowdata = snewn(max+1, int);
-
-	if (verbose) {
-	    int thiswid;
-	    /*
-	     * Work out the maximum text width of the clue numbers
-	     * in a row or column, so we can print the solver's
-	     * working in a nicely lined up way.
-	     */
-	    for (i = 0; i < (w+h); i++) {
-		char buf[80];
-		for (thiswid = -1, j = 0; j < s->common->rowlen[i]; j++)
-		    thiswid += sprintf
-                        (buf, " %d",
-                         s->common->rowdata[s->common->rowsize*i+j]);
-		if (cluewid < thiswid)
-		    cluewid = thiswid;
-	    }
-	}
-
-	solve_puzzle(s, NULL, w, h, matrix, workspace,
-		     changed_h, changed_w, rowdata, cluewid);
-
-	for (i = 0; i < h; i++) {
-	    for (j = 0; j < w; j++) {
-		int c = (matrix[i*w+j] == UNKNOWN ? '?' :
-			 matrix[i*w+j] == BLOCK ? '#' :
-			 matrix[i*w+j] == DOT ? '.' :
-			 '!');
-		putchar(c);
-	    }
-	    printf("\n");
-	}
-    }
-
-    return 0;
-}
-
-#endif
-
-#ifdef STANDALONE_PICTURE_GENERATOR
-
-/*
- * Main program for the standalone picture generator. To use it,
- * simply provide it with an XBM-format bitmap file (note XBM, not
- * XPM) on standard input, and it will output a game ID in return.
- * For example:
- *
- *   $ ./patternpicture < calligraphic-A.xbm
- *   15x15:2/4/2/2/2/3/3/3.1/3.1/3.1/11/14/12/6/1/2/2/3/4/5/1.3/2.3/1.3/2.3/1.4/9/1.1.3/2.2.3/5.4/3.2
- *
- * That looks easy, of course - all the program has done is to count
- * up the clue numbers! But in fact, it's done more than that: it's
- * also checked that the result is uniquely soluble from just the
- * numbers. If it hadn't been, then it would have also left some
- * filled squares in the playing area as extra clues.
- *
- *   $ ./patternpicture < cube.xbm
- *   15x15:10/2.1/1.1.1/1.1.1/1.1.1/1.1.1/1.1.1/1.1.1/1.1.1/1.10/1.1.1/1.1.1/1.1.1/2.1/10/10/1.2/1.1.1/1.1.1/1.1.1/10.1/1.1.1/1.1.1/1.1.1/1.1.1/1.1.1/1.1.1/1.1.1/1.2/10,TNINzzzzGNzw
- *
- * This enables a reasonably convenient design workflow for coming up
- * with pictorial Pattern puzzles which _are_ uniquely soluble without
- * those inelegant pre-filled squares. Fire up a bitmap editor (X11
- * bitmap(1) is good enough), save a trial .xbm, and then test it by
- * running a command along the lines of
- *
- *   $ ./pattern $(./patternpicture < test.xbm)
- *
- * If the resulting window pops up with some pre-filled squares, then
- * that tells you which parts of the image are giving rise to
- * ambiguities, so try making tweaks in those areas, try the test
- * command again, and see if it helps. Once you have a design for
- * which the Pattern starting grid comes out empty, there's your game
- * ID.
- */
-
-#include <time.h>
-
-int main(int argc, char **argv)
-{
-    game_params *par;
-    char *params, *desc;
-    random_state *rs;
-    time_t seed = time(NULL);
-    char buf[4096];
-    int i;
-    int x, y;
-
-    par = default_params();
-    if (argc > 1)
-	decode_params(par, argv[1]);   /* get difficulty */
-    par->w = par->h = -1;
-
-    /*
-     * Now read an XBM file from standard input. This is simple and
-     * hacky and will do very little error detection, so don't feed
-     * it bogus data.
-     */
-    picture = NULL;
-    x = y = 0;
-    while (fgets(buf, sizeof(buf), stdin)) {
-	buf[strcspn(buf, "\r\n")] = '\0';
-	if (!strncmp(buf, "#define", 7)) {
-	    /*
-	     * Lines starting `#define' give the width and height.
-	     */
-	    char *num = buf + strlen(buf);
-	    char *symend;
-
-	    while (num > buf && isdigit((unsigned char)num[-1]))
-		num--;
-	    symend = num;
-	    while (symend > buf && isspace((unsigned char)symend[-1]))
-		symend--;
-
-	    if (symend-5 >= buf && !strncmp(symend-5, "width", 5))
-		par->w = atoi(num);
-	    else if (symend-6 >= buf && !strncmp(symend-6, "height", 6))
-		par->h = atoi(num);
-	} else {
-	    /*
-	     * Otherwise, break the string up into words and take
-	     * any word of the form `0x' plus hex digits to be a
-	     * byte.
-	     */
-	    char *p, *wordstart;
-
-	    if (!picture) {
-		if (par->w < 0 || par->h < 0) {
-		    printf("failed to read width and height\n");
-		    return 1;
-		}
-		picture = snewn(par->w * par->h, unsigned char);
-		for (i = 0; i < par->w * par->h; i++)
-		    picture[i] = GRID_UNKNOWN;
-	    }
-
-	    p = buf;
-	    while (*p) {
-		while (*p && (*p == ',' || isspace((unsigned char)*p)))
-		    p++;
-		wordstart = p;
-		while (*p && !(*p == ',' || *p == '}' ||
-			       isspace((unsigned char)*p)))
-		    p++;
-		if (*p)
-		    *p++ = '\0';
-
-		if (wordstart[0] == '0' &&
-		    (wordstart[1] == 'x' || wordstart[1] == 'X') &&
-		    !wordstart[2 + strspn(wordstart+2,
-					  "0123456789abcdefABCDEF")]) {
-		    unsigned long byte = strtoul(wordstart+2, NULL, 16);
-		    for (i = 0; i < 8; i++) {
-			int bit = (byte >> i) & 1;
-			if (y < par->h && x < par->w)
-			    picture[y * par->w + x] =
-                                bit ? GRID_FULL : GRID_EMPTY;
-			x++;
-		    }
-
-		    if (x >= par->w) {
-			x = 0;
-			y++;
-		    }
-		}
-	    }
-	}
-    }
-
-    for (i = 0; i < par->w * par->h; i++)
-	if (picture[i] == GRID_UNKNOWN) {
-	    fprintf(stderr, "failed to read enough bitmap data\n");
-	    return 1;
-	}
-
-    rs = random_new((void*)&seed, sizeof(time_t));
-
-    desc = new_game_desc(par, rs, NULL, FALSE);
-    params = encode_params(par, FALSE);
-    printf("%s:%s\n", params, desc);
-
-    sfree(desc);
-    sfree(params);
-    free_params(par);
-    random_free(rs);
-
-    return 0;
-}
-
-#endif
-
-/* vim: set shiftwidth=4 tabstop=8: */