ref: e6cdd70df867f064b0358dc3dba56d2667ab80a5
dir: /map.c/
/*
* map.c: Game involving four-colouring a map.
*/
/*
* TODO:
*
* - clue marking
* - better four-colouring algorithm?
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <ctype.h>
#include <limits.h>
#ifdef NO_TGMATH_H
# include <math.h>
#else
# include <tgmath.h>
#endif
#include "puzzles.h"
/*
* In standalone solver mode, `verbose' is a variable which can be
* set by command-line option; in debugging mode it's simply always
* true.
*/
#if defined STANDALONE_SOLVER
#define SOLVER_DIAGNOSTICS
static bool verbose = false;
#elif defined SOLVER_DIAGNOSTICS
#define verbose true
#endif
/*
* I don't seriously anticipate wanting to change the number of
* colours used in this game, but it doesn't cost much to use a
* #define just in case :-)
*/
#define FOUR 4
#define THREE (FOUR-1)
#define FIVE (FOUR+1)
#define SIX (FOUR+2)
/*
* Difficulty levels. I do some macro ickery here to ensure that my
* enum and the various forms of my name list always match up.
*/
#define DIFFLIST(A) \
A(EASY,Easy,e) \
A(NORMAL,Normal,n) \
A(HARD,Hard,h) \
A(RECURSE,Unreasonable,u)
#define ENUM(upper,title,lower) DIFF_ ## upper,
#define TITLE(upper,title,lower) #title,
#define ENCODE(upper,title,lower) #lower
#define CONFIG(upper,title,lower) ":" #title
enum { DIFFLIST(ENUM) DIFFCOUNT };
static char const *const map_diffnames[] = { DIFFLIST(TITLE) };
static char const map_diffchars[] = DIFFLIST(ENCODE);
#define DIFFCONFIG DIFFLIST(CONFIG)
enum { TE, BE, LE, RE }; /* top/bottom/left/right edges */
enum {
COL_BACKGROUND,
COL_GRID,
COL_0, COL_1, COL_2, COL_3,
COL_ERROR, COL_ERRTEXT,
NCOLOURS
};
struct game_params {
int w, h, n, diff;
};
struct map {
int refcount;
int *map;
int *graph;
int n;
int ngraph;
bool *immutable;
int *edgex, *edgey; /* position of a point on each edge */
int *regionx, *regiony; /* position of a point in each region */
};
struct game_state {
game_params p;
struct map *map;
int *colouring, *pencil;
bool completed, cheated;
};
static game_params *default_params(void)
{
game_params *ret = snew(game_params);
#ifdef PORTRAIT_SCREEN
ret->w = 16;
ret->h = 18;
#else
ret->w = 20;
ret->h = 15;
#endif
ret->n = 30;
ret->diff = DIFF_NORMAL;
return ret;
}
static const struct game_params map_presets[] = {
#ifdef PORTRAIT_SCREEN
{16, 18, 30, DIFF_EASY},
{16, 18, 30, DIFF_NORMAL},
{16, 18, 30, DIFF_HARD},
{16, 18, 30, DIFF_RECURSE},
{25, 30, 75, DIFF_NORMAL},
{25, 30, 75, DIFF_HARD},
#else
{20, 15, 30, DIFF_EASY},
{20, 15, 30, DIFF_NORMAL},
{20, 15, 30, DIFF_HARD},
{20, 15, 30, DIFF_RECURSE},
{30, 25, 75, DIFF_NORMAL},
{30, 25, 75, DIFF_HARD},
#endif
};
static bool game_fetch_preset(int i, char **name, game_params **params)
{
game_params *ret;
char str[80];
if (i < 0 || i >= lenof(map_presets))
return false;
ret = snew(game_params);
*ret = map_presets[i];
sprintf(str, "%dx%d, %d regions, %s", ret->w, ret->h, ret->n,
map_diffnames[ret->diff]);
*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 *params, char const *string)
{
char const *p = string;
params->w = atoi(p);
while (*p && isdigit((unsigned char)*p)) p++;
if (*p == 'x') {
p++;
params->h = atoi(p);
while (*p && isdigit((unsigned char)*p)) p++;
} else {
params->h = params->w;
}
if (*p == 'n') {
p++;
params->n = atoi(p);
while (*p && (*p == '.' || isdigit((unsigned char)*p))) p++;
} else {
if (params->h > 0 && params->w > 0 &&
params->w <= INT_MAX / params->h)
params->n = params->w * params->h / 8;
}
if (*p == 'd') {
int i;
p++;
for (i = 0; i < DIFFCOUNT; i++)
if (*p == map_diffchars[i])
params->diff = i;
if (*p) p++;
}
}
static char *encode_params(const game_params *params, bool full)
{
char ret[400];
sprintf(ret, "%dx%dn%d", params->w, params->h, params->n);
if (full)
sprintf(ret + strlen(ret), "d%c", map_diffchars[params->diff]);
return dupstr(ret);
}
static config_item *game_configure(const game_params *params)
{
config_item *ret;
char buf[80];
ret = snewn(5, config_item);
ret[0].name = "Width";
ret[0].type = C_STRING;
sprintf(buf, "%d", params->w);
ret[0].u.string.sval = dupstr(buf);
ret[1].name = "Height";
ret[1].type = C_STRING;
sprintf(buf, "%d", params->h);
ret[1].u.string.sval = dupstr(buf);
ret[2].name = "Regions";
ret[2].type = C_STRING;
sprintf(buf, "%d", params->n);
ret[2].u.string.sval = dupstr(buf);
ret[3].name = "Difficulty";
ret[3].type = C_CHOICES;
ret[3].u.choices.choicenames = DIFFCONFIG;
ret[3].u.choices.selected = params->diff;
ret[4].name = NULL;
ret[4].type = C_END;
return ret;
}
static game_params *custom_params(const config_item *cfg)
{
game_params *ret = snew(game_params);
ret->w = atoi(cfg[0].u.string.sval);
ret->h = atoi(cfg[1].u.string.sval);
ret->n = atoi(cfg[2].u.string.sval);
ret->diff = cfg[3].u.choices.selected;
return ret;
}
static const char *validate_params(const game_params *params, bool full)
{
if (params->w < 2 || params->h < 2)
return "Width and height must be at least two";
if (params->w > INT_MAX / 2 / params->h)
return "Width times height must not be unreasonably large";
if (params->n < 5)
return "Must have at least five regions";
if (params->n > params->w * params->h)
return "Too many regions to fit in grid";
return NULL;
}
/* ----------------------------------------------------------------------
* Cumulative frequency table functions.
*/
/*
* Initialise a cumulative frequency table. (Hardly worth writing
* this function; all it does is to initialise everything in the
* array to zero.)
*/
static void cf_init(int *table, int n)
{
int i;
for (i = 0; i < n; i++)
table[i] = 0;
}
/*
* Increment the count of symbol `sym' by `count'.
*/
static void cf_add(int *table, int n, int sym, int count)
{
int bit;
bit = 1;
while (sym != 0) {
if (sym & bit) {
table[sym] += count;
sym &= ~bit;
}
bit <<= 1;
}
table[0] += count;
}
/*
* Cumulative frequency lookup: return the total count of symbols
* with value less than `sym'.
*/
static int cf_clookup(int *table, int n, int sym)
{
int bit, index, limit, count;
if (sym == 0)
return 0;
assert(0 < sym && sym <= n);
count = table[0]; /* start with the whole table size */
bit = 1;
while (bit < n)
bit <<= 1;
limit = n;
while (bit > 0) {
/*
* Find the least number with its lowest set bit in this
* position which is greater than or equal to sym.
*/
index = ((sym + bit - 1) &~ (bit * 2 - 1)) + bit;
if (index < limit) {
count -= table[index];
limit = index;
}
bit >>= 1;
}
return count;
}
/*
* Single frequency lookup: return the count of symbol `sym'.
*/
static int cf_slookup(int *table, int n, int sym)
{
int count, bit;
assert(0 <= sym && sym < n);
count = table[sym];
for (bit = 1; sym+bit < n && !(sym & bit); bit <<= 1)
count -= table[sym+bit];
return count;
}
/*
* Return the largest symbol index such that the cumulative
* frequency up to that symbol is less than _or equal to_ count.
*/
static int cf_whichsym(int *table, int n, int count) {
int bit, sym, top;
assert(count >= 0 && count < table[0]);
bit = 1;
while (bit < n)
bit <<= 1;
sym = 0;
top = table[0];
while (bit > 0) {
if (sym+bit < n) {
if (count >= top - table[sym+bit])
sym += bit;
else
top -= table[sym+bit];
}
bit >>= 1;
}
return sym;
}
/* ----------------------------------------------------------------------
* Map generation.
*
* FIXME: this isn't entirely optimal at present, because it
* inherently prioritises growing the largest region since there
* are more squares adjacent to it. This acts as a destabilising
* influence leading to a few large regions and mostly small ones.
* It might be better to do it some other way.
*/
#define WEIGHT_INCREASED 2 /* for increased perimeter */
#define WEIGHT_DECREASED 4 /* for decreased perimeter */
#define WEIGHT_UNCHANGED 3 /* for unchanged perimeter */
/*
* Look at a square and decide which colours can be extended into
* it.
*
* If called with index < 0, it adds together one of
* WEIGHT_INCREASED, WEIGHT_DECREASED or WEIGHT_UNCHANGED for each
* colour that has a valid extension (according to the effect that
* it would have on the perimeter of the region being extended) and
* returns the overall total.
*
* If called with index >= 0, it returns one of the possible
* colours depending on the value of index, in such a way that the
* number of possible inputs which would give rise to a given
* return value correspond to the weight of that value.
*/
static int extend_options(int w, int h, int n, int *map,
int x, int y, int index)
{
int c, i, dx, dy;
int col[8];
int total = 0;
if (map[y*w+x] >= 0) {
assert(index < 0);
return 0; /* can't do this square at all */
}
/*
* Fetch the eight neighbours of this square, in order around
* the square.
*/
for (dy = -1; dy <= +1; dy++)
for (dx = -1; dx <= +1; dx++) {
int index = (dy < 0 ? 6-dx : dy > 0 ? 2+dx : 2*(1+dx));
if (x+dx >= 0 && x+dx < w && y+dy >= 0 && y+dy < h)
col[index] = map[(y+dy)*w+(x+dx)];
else
col[index] = -1;
}
/*
* Iterate over each colour that might be feasible.
*
* FIXME: this routine currently has O(n) running time. We
* could turn it into O(FOUR) by only bothering to iterate over
* the colours mentioned in the four neighbouring squares.
*/
for (c = 0; c < n; c++) {
int count, neighbours, runs;
/*
* One of the even indices of col (representing the
* orthogonal neighbours of this square) must be equal to
* c, or else this square is not adjacent to region c and
* obviously cannot become an extension of it at this time.
*/
neighbours = 0;
for (i = 0; i < 8; i += 2)
if (col[i] == c)
neighbours++;
if (!neighbours)
continue;
/*
* Now we know this square is adjacent to region c. The
* next question is, would extending it cause the region to
* become non-simply-connected? If so, we mustn't do it.
*
* We determine this by looking around col to see if we can
* find more than one separate run of colour c.
*/
runs = 0;
for (i = 0; i < 8; i++)
if (col[i] == c && col[(i+1) & 7] != c)
runs++;
if (runs > 1)
continue;
assert(runs == 1);
/*
* This square is a possibility. Determine its effect on
* the region's perimeter (computed from the number of
* orthogonal neighbours - 1 means a perimeter increase, 3
* a decrease, 2 no change; 4 is impossible because the
* region would already not be simply connected) and we're
* done.
*/
assert(neighbours > 0 && neighbours < 4);
count = (neighbours == 1 ? WEIGHT_INCREASED :
neighbours == 2 ? WEIGHT_UNCHANGED : WEIGHT_DECREASED);
total += count;
if (index >= 0 && index < count)
return c;
else
index -= count;
}
assert(index < 0);
return total;
}
static void genmap(int w, int h, int n, int *map, random_state *rs)
{
int wh = w*h;
int x, y, i, k;
int *tmp;
assert(n <= wh);
tmp = snewn(wh, int);
/*
* Clear the map, and set up `tmp' as a list of grid indices.
*/
for (i = 0; i < wh; i++) {
map[i] = -1;
tmp[i] = i;
}
/*
* Place the region seeds by selecting n members from `tmp'.
*/
k = wh;
for (i = 0; i < n; i++) {
int j = random_upto(rs, k);
map[tmp[j]] = i;
tmp[j] = tmp[--k];
}
/*
* Re-initialise `tmp' as a cumulative frequency table. This
* will store the number of possible region colours we can
* extend into each square.
*/
cf_init(tmp, wh);
/*
* Go through the grid and set up the initial cumulative
* frequencies.
*/
for (y = 0; y < h; y++)
for (x = 0; x < w; x++)
cf_add(tmp, wh, y*w+x,
extend_options(w, h, n, map, x, y, -1));
/*
* Now repeatedly choose a square we can extend a region into,
* and do so.
*/
while (tmp[0] > 0) {
int k = random_upto(rs, tmp[0]);
int sq;
int colour;
int xx, yy;
sq = cf_whichsym(tmp, wh, k);
k -= cf_clookup(tmp, wh, sq);
x = sq % w;
y = sq / w;
colour = extend_options(w, h, n, map, x, y, k);
map[sq] = colour;
/*
* Re-scan the nine cells around the one we've just
* modified.
*/
for (yy = max(y-1, 0); yy < min(y+2, h); yy++)
for (xx = max(x-1, 0); xx < min(x+2, w); xx++) {
cf_add(tmp, wh, yy*w+xx,
-cf_slookup(tmp, wh, yy*w+xx) +
extend_options(w, h, n, map, xx, yy, -1));
}
}
/*
* Finally, go through and normalise the region labels into
* order, meaning that indistinguishable maps are actually
* identical.
*/
for (i = 0; i < n; i++)
tmp[i] = -1;
k = 0;
for (i = 0; i < wh; i++) {
assert(map[i] >= 0);
if (tmp[map[i]] < 0)
tmp[map[i]] = k++;
map[i] = tmp[map[i]];
}
sfree(tmp);
}
/* ----------------------------------------------------------------------
* Functions to handle graphs.
*/
/*
* Having got a map in a square grid, convert it into a graph
* representation.
*/
static int gengraph(int w, int h, int n, int *map, int *graph)
{
int i, j, x, y;
/*
* Start by setting the graph up as an adjacency matrix. We'll
* turn it into a list later.
*/
for (i = 0; i < n*n; i++)
graph[i] = 0;
/*
* Iterate over the map looking for all adjacencies.
*/
for (y = 0; y < h; y++)
for (x = 0; x < w; x++) {
int v, vx, vy;
v = map[y*w+x];
if (x+1 < w && (vx = map[y*w+(x+1)]) != v)
graph[v*n+vx] = graph[vx*n+v] = 1;
if (y+1 < h && (vy = map[(y+1)*w+x]) != v)
graph[v*n+vy] = graph[vy*n+v] = 1;
}
/*
* Turn the matrix into a list.
*/
for (i = j = 0; i < n*n; i++)
if (graph[i])
graph[j++] = i;
return j;
}
static int graph_edge_index(int *graph, int n, int ngraph, int i, int j)
{
int v = i*n+j;
int top, bot, mid;
bot = -1;
top = ngraph;
while (top - bot > 1) {
mid = (top + bot) / 2;
if (graph[mid] == v)
return mid;
else if (graph[mid] < v)
bot = mid;
else
top = mid;
}
return -1;
}
#define graph_adjacent(graph, n, ngraph, i, j) \
(graph_edge_index((graph), (n), (ngraph), (i), (j)) >= 0)
static int graph_vertex_start(int *graph, int n, int ngraph, int i)
{
int v = i*n;
int top, bot, mid;
bot = -1;
top = ngraph;
while (top - bot > 1) {
mid = (top + bot) / 2;
if (graph[mid] < v)
bot = mid;
else
top = mid;
}
return top;
}
/* ----------------------------------------------------------------------
* Generate a four-colouring of a graph.
*
* FIXME: it would be nice if we could convert this recursion into
* pseudo-recursion using some sort of explicit stack array, for
* the sake of the Palm port and its limited stack.
*/
static bool fourcolour_recurse(int *graph, int n, int ngraph,
int *colouring, int *scratch, random_state *rs)
{
int nfree, nvert, start, i, j, k, c, ci;
int cs[FOUR];
/*
* Find the smallest number of free colours in any uncoloured
* vertex, and count the number of such vertices.
*/
nfree = FIVE; /* start off bigger than FOUR! */
nvert = 0;
for (i = 0; i < n; i++)
if (colouring[i] < 0 && scratch[i*FIVE+FOUR] <= nfree) {
if (nfree > scratch[i*FIVE+FOUR]) {
nfree = scratch[i*FIVE+FOUR];
nvert = 0;
}
nvert++;
}
/*
* If there aren't any uncoloured vertices at all, we're done.
*/
if (nvert == 0)
return true; /* we've got a colouring! */
/*
* Pick a random vertex in that set.
*/
j = random_upto(rs, nvert);
for (i = 0; i < n; i++)
if (colouring[i] < 0 && scratch[i*FIVE+FOUR] == nfree)
if (j-- == 0)
break;
assert(i < n);
start = graph_vertex_start(graph, n, ngraph, i);
/*
* Loop over the possible colours for i, and recurse for each
* one.
*/
ci = 0;
for (c = 0; c < FOUR; c++)
if (scratch[i*FIVE+c] == 0)
cs[ci++] = c;
shuffle(cs, ci, sizeof(*cs), rs);
while (ci-- > 0) {
c = cs[ci];
/*
* Fill in this colour.
*/
colouring[i] = c;
/*
* Update the scratch space to reflect a new neighbour
* of this colour for each neighbour of vertex i.
*/
for (j = start; j < ngraph && graph[j] < n*(i+1); j++) {
k = graph[j] - i*n;
if (scratch[k*FIVE+c] == 0)
scratch[k*FIVE+FOUR]--;
scratch[k*FIVE+c]++;
}
/*
* Recurse.
*/
if (fourcolour_recurse(graph, n, ngraph, colouring, scratch, rs))
return true; /* got one! */
/*
* If that didn't work, clean up and try again with a
* different colour.
*/
for (j = start; j < ngraph && graph[j] < n*(i+1); j++) {
k = graph[j] - i*n;
scratch[k*FIVE+c]--;
if (scratch[k*FIVE+c] == 0)
scratch[k*FIVE+FOUR]++;
}
colouring[i] = -1;
}
/*
* If we reach here, we were unable to find a colouring at all.
* (This doesn't necessarily mean the Four Colour Theorem is
* violated; it might just mean we've gone down a dead end and
* need to back up and look somewhere else. It's only an FCT
* violation if we get all the way back up to the top level and
* still fail.)
*/
return false;
}
static void fourcolour(int *graph, int n, int ngraph, int *colouring,
random_state *rs)
{
int *scratch;
int i;
bool retd;
/*
* For each vertex and each colour, we store the number of
* neighbours that have that colour. Also, we store the number
* of free colours for the vertex.
*/
scratch = snewn(n * FIVE, int);
for (i = 0; i < n * FIVE; i++)
scratch[i] = (i % FIVE == FOUR ? FOUR : 0);
/*
* Clear the colouring to start with.
*/
for (i = 0; i < n; i++)
colouring[i] = -1;
retd = fourcolour_recurse(graph, n, ngraph, colouring, scratch, rs);
assert(retd); /* by the Four Colour Theorem :-) */
sfree(scratch);
}
/* ----------------------------------------------------------------------
* Non-recursive solver.
*/
struct solver_scratch {
unsigned char *possible; /* bitmap of colours for each region */
int *graph;
int n;
int ngraph;
int *bfsqueue;
int *bfscolour;
#ifdef SOLVER_DIAGNOSTICS
int *bfsprev;
#endif
int depth;
};
static struct solver_scratch *new_scratch(int *graph, int n, int ngraph)
{
struct solver_scratch *sc;
sc = snew(struct solver_scratch);
sc->graph = graph;
sc->n = n;
sc->ngraph = ngraph;
sc->possible = snewn(n, unsigned char);
sc->depth = 0;
sc->bfsqueue = snewn(n, int);
sc->bfscolour = snewn(n, int);
#ifdef SOLVER_DIAGNOSTICS
sc->bfsprev = snewn(n, int);
#endif
return sc;
}
static void free_scratch(struct solver_scratch *sc)
{
sfree(sc->possible);
sfree(sc->bfsqueue);
sfree(sc->bfscolour);
#ifdef SOLVER_DIAGNOSTICS
sfree(sc->bfsprev);
#endif
sfree(sc);
}
/*
* Count the bits in a word. Only needs to cope with FOUR bits.
*/
static int bitcount(int word)
{
assert(FOUR <= 4); /* or this needs changing */
word = ((word & 0xA) >> 1) + (word & 0x5);
word = ((word & 0xC) >> 2) + (word & 0x3);
return word;
}
#ifdef SOLVER_DIAGNOSTICS
static const char colnames[FOUR] = { 'R', 'Y', 'G', 'B' };
#endif
static bool place_colour(struct solver_scratch *sc,
int *colouring, int index, int colour
#ifdef SOLVER_DIAGNOSTICS
, const char *verb
#endif
)
{
int *graph = sc->graph, n = sc->n, ngraph = sc->ngraph;
int j, k;
if (!(sc->possible[index] & (1 << colour))) {
#ifdef SOLVER_DIAGNOSTICS
if (verbose)
printf("%*scannot place %c in region %d\n", 2*sc->depth, "",
colnames[colour], index);
#endif
return false; /* can't do it */
}
sc->possible[index] = 1 << colour;
colouring[index] = colour;
#ifdef SOLVER_DIAGNOSTICS
if (verbose)
printf("%*s%s %c in region %d\n", 2*sc->depth, "",
verb, colnames[colour], index);
#endif
/*
* Rule out this colour from all the region's neighbours.
*/
for (j = graph_vertex_start(graph, n, ngraph, index);
j < ngraph && graph[j] < n*(index+1); j++) {
k = graph[j] - index*n;
#ifdef SOLVER_DIAGNOSTICS
if (verbose && (sc->possible[k] & (1 << colour)))
printf("%*s ruling out %c in region %d\n", 2*sc->depth, "",
colnames[colour], k);
#endif
sc->possible[k] &= ~(1 << colour);
}
return true;
}
#ifdef SOLVER_DIAGNOSTICS
static char *colourset(char *buf, int set)
{
int i;
char *p = buf;
const char *sep = "";
for (i = 0; i < FOUR; i++)
if (set & (1 << i)) {
p += sprintf(p, "%s%c", sep, colnames[i]);
sep = ",";
}
return buf;
}
#endif
/*
* Returns 0 for impossible, 1 for success, 2 for failure to
* converge (i.e. puzzle is either ambiguous or just too
* difficult).
*/
static int map_solver(struct solver_scratch *sc,
int *graph, int n, int ngraph, int *colouring,
int difficulty)
{
int i;
if (sc->depth == 0) {
/*
* Initialise scratch space.
*/
for (i = 0; i < n; i++)
sc->possible[i] = (1 << FOUR) - 1;
/*
* Place clues.
*/
for (i = 0; i < n; i++)
if (colouring[i] >= 0) {
if (!place_colour(sc, colouring, i, colouring[i]
#ifdef SOLVER_DIAGNOSTICS
, "initial clue:"
#endif
)) {
#ifdef SOLVER_DIAGNOSTICS
if (verbose)
printf("%*sinitial clue set is inconsistent\n",
2*sc->depth, "");
#endif
return 0; /* the clues aren't even consistent! */
}
}
}
/*
* Now repeatedly loop until we find nothing further to do.
*/
while (1) {
bool done_something = false;
if (difficulty < DIFF_EASY)
break; /* can't do anything at all! */
/*
* Simplest possible deduction: find a region with only one
* possible colour.
*/
for (i = 0; i < n; i++) if (colouring[i] < 0) {
int p = sc->possible[i];
if (p == 0) {
#ifdef SOLVER_DIAGNOSTICS
if (verbose)
printf("%*sregion %d has no possible colours left\n",
2*sc->depth, "", i);
#endif
return 0; /* puzzle is inconsistent */
}
if ((p & (p-1)) == 0) { /* p is a power of two */
int c;
bool ret;
for (c = 0; c < FOUR; c++)
if (p == (1 << c))
break;
assert(c < FOUR);
ret = place_colour(sc, colouring, i, c
#ifdef SOLVER_DIAGNOSTICS
, "placing"
#endif
);
/*
* place_colour() can only fail if colour c was not
* even a _possibility_ for region i, and we're
* pretty sure it was because we checked before
* calling place_colour(). So we can safely assert
* here rather than having to return a nice
* friendly error code.
*/
assert(ret);
done_something = true;
}
}
if (done_something)
continue;
if (difficulty < DIFF_NORMAL)
break; /* can't do anything harder */
/*
* Failing that, go up one level. Look for pairs of regions
* which (a) both have the same pair of possible colours,
* (b) are adjacent to one another, (c) are adjacent to the
* same region, and (d) that region still thinks it has one
* or both of those possible colours.
*
* Simplest way to do this is by going through the graph
* edge by edge, so that we start with property (b) and
* then look for (a) and finally (c) and (d).
*/
for (i = 0; i < ngraph; i++) {
int j1 = graph[i] / n, j2 = graph[i] % n;
int j, k, v, v2;
#ifdef SOLVER_DIAGNOSTICS
bool started = false;
#endif
if (j1 > j2)
continue; /* done it already, other way round */
if (colouring[j1] >= 0 || colouring[j2] >= 0)
continue; /* they're not undecided */
if (sc->possible[j1] != sc->possible[j2])
continue; /* they don't have the same possibles */
v = sc->possible[j1];
/*
* See if v contains exactly two set bits.
*/
v2 = v & -v; /* find lowest set bit */
v2 = v & ~v2; /* clear it */
if (v2 == 0 || (v2 & (v2-1)) != 0) /* not power of 2 */
continue;
/*
* We've found regions j1 and j2 satisfying properties
* (a) and (b): they have two possible colours between
* them, and since they're adjacent to one another they
* must use _both_ those colours between them.
* Therefore, if they are both adjacent to any other
* region then that region cannot be either colour.
*
* Go through the neighbours of j1 and see if any are
* shared with j2.
*/
for (j = graph_vertex_start(graph, n, ngraph, j1);
j < ngraph && graph[j] < n*(j1+1); j++) {
k = graph[j] - j1*n;
if (graph_adjacent(graph, n, ngraph, k, j2) &&
(sc->possible[k] & v)) {
#ifdef SOLVER_DIAGNOSTICS
if (verbose) {
char buf[80];
if (!started)
printf("%*sadjacent regions %d,%d share colours"
" %s\n", 2*sc->depth, "", j1, j2,
colourset(buf, v));
started = true;
printf("%*s ruling out %s in region %d\n",2*sc->depth,
"", colourset(buf, sc->possible[k] & v), k);
}
#endif
sc->possible[k] &= ~v;
done_something = true;
}
}
}
if (done_something)
continue;
if (difficulty < DIFF_HARD)
break; /* can't do anything harder */
/*
* Right; now we get creative. Now we're going to look for
* `forcing chains'. A forcing chain is a path through the
* graph with the following properties:
*
* (a) Each vertex on the path has precisely two possible
* colours.
*
* (b) Each pair of vertices which are adjacent on the
* path share at least one possible colour in common.
*
* (c) Each vertex in the middle of the path shares _both_
* of its colours with at least one of its neighbours
* (not the same one with both neighbours).
*
* These together imply that at least one of the possible
* colour choices at one end of the path forces _all_ the
* rest of the colours along the path. In order to make
* real use of this, we need further properties:
*
* (c) Ruling out some colour C from the vertex at one end
* of the path forces the vertex at the other end to
* take colour C.
*
* (d) The two end vertices are mutually adjacent to some
* third vertex.
*
* (e) That third vertex currently has C as a possibility.
*
* If we can find all of that lot, we can deduce that at
* least one of the two ends of the forcing chain has
* colour C, and that therefore the mutually adjacent third
* vertex does not.
*
* To find forcing chains, we're going to start a bfs at
* each suitable vertex of the graph, once for each of its
* two possible colours.
*/
for (i = 0; i < n; i++) {
int c;
if (colouring[i] >= 0 || bitcount(sc->possible[i]) != 2)
continue;
for (c = 0; c < FOUR; c++)
if (sc->possible[i] & (1 << c)) {
int j, k, gi, origc, currc, head, tail;
/*
* Try a bfs from this vertex, ruling out
* colour c.
*
* Within this loop, we work in colour bitmaps
* rather than actual colours, because
* converting back and forth is a needless
* computational expense.
*/
origc = 1 << c;
for (j = 0; j < n; j++) {
sc->bfscolour[j] = -1;
#ifdef SOLVER_DIAGNOSTICS
sc->bfsprev[j] = -1;
#endif
}
head = tail = 0;
sc->bfsqueue[tail++] = i;
sc->bfscolour[i] = sc->possible[i] &~ origc;
while (head < tail) {
j = sc->bfsqueue[head++];
currc = sc->bfscolour[j];
/*
* Try neighbours of j.
*/
for (gi = graph_vertex_start(graph, n, ngraph, j);
gi < ngraph && graph[gi] < n*(j+1); gi++) {
k = graph[gi] - j*n;
/*
* To continue with the bfs in vertex
* k, we need k to be
* (a) not already visited
* (b) have two possible colours
* (c) those colours include currc.
*/
if (sc->bfscolour[k] < 0 &&
colouring[k] < 0 &&
bitcount(sc->possible[k]) == 2 &&
(sc->possible[k] & currc)) {
sc->bfsqueue[tail++] = k;
sc->bfscolour[k] =
sc->possible[k] &~ currc;
#ifdef SOLVER_DIAGNOSTICS
sc->bfsprev[k] = j;
#endif
}
/*
* One other possibility is that k
* might be the region in which we can
* make a real deduction: if it's
* adjacent to i, contains currc as a
* possibility, and currc is equal to
* the original colour we ruled out.
*/
if (currc == origc &&
graph_adjacent(graph, n, ngraph, k, i) &&
(sc->possible[k] & currc)) {
#ifdef SOLVER_DIAGNOSTICS
if (verbose) {
char buf[80];
const char *sep = "";
int r;
printf("%*sforcing chain, colour %s, ",
2*sc->depth, "",
colourset(buf, origc));
for (r = j; r != -1; r = sc->bfsprev[r]) {
printf("%s%d", sep, r);
sep = "-";
}
printf("\n%*s ruling out %s in region"
" %d\n", 2*sc->depth, "",
colourset(buf, origc), k);
}
#endif
sc->possible[k] &= ~origc;
done_something = true;
}
}
}
assert(tail <= n);
}
}
if (!done_something)
break;
}
/*
* See if we've got a complete solution, and return if so.
*/
for (i = 0; i < n; i++)
if (colouring[i] < 0)
break;
if (i == n) {
#ifdef SOLVER_DIAGNOSTICS
if (verbose)
printf("%*sone solution found\n", 2*sc->depth, "");
#endif
return 1; /* success! */
}
/*
* If recursion is not permissible, we now give up.
*/
if (difficulty < DIFF_RECURSE) {
#ifdef SOLVER_DIAGNOSTICS
if (verbose)
printf("%*sunable to proceed further without recursion\n",
2*sc->depth, "");
#endif
return 2; /* unable to complete */
}
/*
* Now we've got to do something recursive. So first hunt for a
* currently-most-constrained region.
*/
{
int best, bestc;
struct solver_scratch *rsc;
int *subcolouring, *origcolouring;
int ret, subret;
bool we_already_got_one;
best = -1;
bestc = FIVE;
for (i = 0; i < n; i++) if (colouring[i] < 0) {
int p = sc->possible[i];
enum { compile_time_assertion = 1 / (FOUR <= 4) };
int c;
/* Count the set bits. */
c = (p & 5) + ((p >> 1) & 5);
c = (c & 3) + ((c >> 2) & 3);
assert(c > 1); /* or colouring[i] would be >= 0 */
if (c < bestc) {
best = i;
bestc = c;
}
}
assert(best >= 0); /* or we'd be solved already */
#ifdef SOLVER_DIAGNOSTICS
if (verbose)
printf("%*srecursing on region %d\n", 2*sc->depth, "", best);
#endif
/*
* Now iterate over the possible colours for this region.
*/
rsc = new_scratch(graph, n, ngraph);
rsc->depth = sc->depth + 1;
origcolouring = snewn(n, int);
memcpy(origcolouring, colouring, n * sizeof(int));
subcolouring = snewn(n, int);
we_already_got_one = false;
ret = 0;
for (i = 0; i < FOUR; i++) {
if (!(sc->possible[best] & (1 << i)))
continue;
memcpy(rsc->possible, sc->possible, n);
memcpy(subcolouring, origcolouring, n * sizeof(int));
place_colour(rsc, subcolouring, best, i
#ifdef SOLVER_DIAGNOSTICS
, "trying"
#endif
);
subret = map_solver(rsc, graph, n, ngraph,
subcolouring, difficulty);
#ifdef SOLVER_DIAGNOSTICS
if (verbose) {
printf("%*sretracting %c in region %d; found %s\n",
2*sc->depth, "", colnames[i], best,
subret == 0 ? "no solutions" :
subret == 1 ? "one solution" : "multiple solutions");
}
#endif
/*
* If this possibility turned up more than one valid
* solution, or if it turned up one and we already had
* one, we're definitely ambiguous.
*/
if (subret == 2 || (subret == 1 && we_already_got_one)) {
ret = 2;
break;
}
/*
* If this possibility turned up one valid solution and
* it's the first we've seen, copy it into the output.
*/
if (subret == 1) {
memcpy(colouring, subcolouring, n * sizeof(int));
we_already_got_one = true;
ret = 1;
}
/*
* Otherwise, this guess led to a contradiction, so we
* do nothing.
*/
}
sfree(origcolouring);
sfree(subcolouring);
free_scratch(rsc);
#ifdef SOLVER_DIAGNOSTICS
if (verbose && sc->depth == 0) {
printf("%*s%s found\n",
2*sc->depth, "",
ret == 0 ? "no solutions" :
ret == 1 ? "one solution" : "multiple solutions");
}
#endif
return ret;
}
}
/* ----------------------------------------------------------------------
* Game generation main function.
*/
static char *new_game_desc(const game_params *params, random_state *rs,
char **aux, bool interactive)
{
struct solver_scratch *sc = NULL;
int *map, *graph, ngraph, *colouring, *colouring2, *regions;
int i, j, w, h, n, solveret, cfreq[FOUR];
int wh;
int mindiff, tries;
#ifdef GENERATION_DIAGNOSTICS
int x, y;
#endif
char *ret, buf[80];
int retlen, retsize;
w = params->w;
h = params->h;
n = params->n;
wh = w*h;
*aux = NULL;
map = snewn(wh, int);
graph = snewn(n*n, int);
colouring = snewn(n, int);
colouring2 = snewn(n, int);
regions = snewn(n, int);
/*
* This is the minimum difficulty below which we'll completely
* reject a map design. Normally we set this to one below the
* requested difficulty, ensuring that we have the right
* result. However, for particularly dense maps or maps with
* particularly few regions it might not be possible to get the
* desired difficulty, so we will eventually drop this down to
* -1 to indicate that any old map will do.
*/
mindiff = params->diff;
tries = 50;
while (1) {
/*
* Create the map.
*/
genmap(w, h, n, map, rs);
#ifdef GENERATION_DIAGNOSTICS
for (y = 0; y < h; y++) {
for (x = 0; x < w; x++) {
int v = map[y*w+x];
if (v >= 62)
putchar('!');
else if (v >= 36)
putchar('a' + v-36);
else if (v >= 10)
putchar('A' + v-10);
else
putchar('0' + v);
}
putchar('\n');
}
#endif
/*
* Convert the map into a graph.
*/
ngraph = gengraph(w, h, n, map, graph);
#ifdef GENERATION_DIAGNOSTICS
for (i = 0; i < ngraph; i++)
printf("%d-%d\n", graph[i]/n, graph[i]%n);
#endif
/*
* Colour the map.
*/
fourcolour(graph, n, ngraph, colouring, rs);
#ifdef GENERATION_DIAGNOSTICS
for (i = 0; i < n; i++)
printf("%d: %d\n", i, colouring[i]);
for (y = 0; y < h; y++) {
for (x = 0; x < w; x++) {
int v = colouring[map[y*w+x]];
if (v >= 36)
putchar('a' + v-36);
else if (v >= 10)
putchar('A' + v-10);
else
putchar('0' + v);
}
putchar('\n');
}
#endif
/*
* Encode the solution as an aux string.
*/
if (*aux) /* in case we've come round again */
sfree(*aux);
retlen = retsize = 0;
ret = NULL;
for (i = 0; i < n; i++) {
int len;
if (colouring[i] < 0)
continue;
len = sprintf(buf, "%s%d:%d", i ? ";" : "S;", colouring[i], i);
if (retlen + len >= retsize) {
retsize = retlen + len + 256;
ret = sresize(ret, retsize, char);
}
strcpy(ret + retlen, buf);
retlen += len;
}
*aux = ret;
/*
* Remove the region colours one by one, keeping
* solubility. Also ensure that there always remains at
* least one region of every colour, so that the user can
* drag from somewhere.
*/
for (i = 0; i < FOUR; i++)
cfreq[i] = 0;
for (i = 0; i < n; i++) {
regions[i] = i;
cfreq[colouring[i]]++;
}
for (i = 0; i < FOUR; i++)
if (cfreq[i] == 0)
continue;
shuffle(regions, n, sizeof(*regions), rs);
if (sc) free_scratch(sc);
sc = new_scratch(graph, n, ngraph);
for (i = 0; i < n; i++) {
j = regions[i];
if (cfreq[colouring[j]] == 1)
continue; /* can't remove last region of colour */
memcpy(colouring2, colouring, n*sizeof(int));
colouring2[j] = -1;
solveret = map_solver(sc, graph, n, ngraph, colouring2,
params->diff);
assert(solveret >= 0); /* mustn't be impossible! */
if (solveret == 1) {
cfreq[colouring[j]]--;
colouring[j] = -1;
}
}
#ifdef GENERATION_DIAGNOSTICS
for (i = 0; i < n; i++)
if (colouring[i] >= 0) {
if (i >= 62)
putchar('!');
else if (i >= 36)
putchar('a' + i-36);
else if (i >= 10)
putchar('A' + i-10);
else
putchar('0' + i);
printf(": %d\n", colouring[i]);
}
#endif
/*
* Finally, check that the puzzle is _at least_ as hard as
* required, and indeed that it isn't already solved.
* (Calling map_solver with negative difficulty ensures the
* latter - if a solver which _does nothing_ can solve it,
* it's too easy!)
*/
memcpy(colouring2, colouring, n*sizeof(int));
if (map_solver(sc, graph, n, ngraph, colouring2,
mindiff - 1) == 1) {
/*
* Drop minimum difficulty if necessary.
*/
if (mindiff > 0 && (n < 9 || n > 2*wh/3)) {
if (tries-- <= 0)
mindiff = 0; /* give up and go for Easy */
}
continue;
}
break;
}
/*
* Encode as a game ID. We do this by:
*
* - first going along the horizontal edges row by row, and
* then the vertical edges column by column
* - encoding the lengths of runs of edges and runs of
* non-edges
* - the decoder will reconstitute the region boundaries from
* this and automatically number them the same way we did
* - then we encode the initial region colours in a Slant-like
* fashion (digits 0-3 interspersed with letters giving
* lengths of runs of empty spaces).
*/
retlen = retsize = 0;
ret = NULL;
{
int run;
bool pv;
/*
* Start with a notional non-edge, so that there'll be an
* explicit `a' to distinguish the case where we start with
* an edge.
*/
run = 1;
pv = false;
for (i = 0; i < w*(h-1) + (w-1)*h; i++) {
int x, y, dx, dy;
bool v;
if (i < w*(h-1)) {
/* Horizontal edge. */
y = i / w;
x = i % w;
dx = 0;
dy = 1;
} else {
/* Vertical edge. */
x = (i - w*(h-1)) / h;
y = (i - w*(h-1)) % h;
dx = 1;
dy = 0;
}
if (retlen + 10 >= retsize) {
retsize = retlen + 256;
ret = sresize(ret, retsize, char);
}
v = (map[y*w+x] != map[(y+dy)*w+(x+dx)]);
if (pv != v) {
ret[retlen++] = 'a'-1 + run;
run = 1;
pv = v;
} else {
/*
* 'z' is a special case in this encoding. Rather
* than meaning a run of 26 and a state switch, it
* means a run of 25 and _no_ state switch, because
* otherwise there'd be no way to encode runs of
* more than 26.
*/
if (run == 25) {
ret[retlen++] = 'z';
run = 0;
}
run++;
}
}
if (retlen + 10 >= retsize) {
retsize = retlen + 256;
ret = sresize(ret, retsize, char);
}
ret[retlen++] = 'a'-1 + run;
ret[retlen++] = ',';
run = 0;
for (i = 0; i < n; i++) {
if (retlen + 10 >= retsize) {
retsize = retlen + 256;
ret = sresize(ret, retsize, char);
}
if (colouring[i] < 0) {
/*
* In _this_ encoding, 'z' is a run of 26, since
* there's no implicit state switch after each run.
* Confusingly different, but more compact.
*/
if (run == 26) {
ret[retlen++] = 'z';
run = 0;
}
run++;
} else {
if (run > 0)
ret[retlen++] = 'a'-1 + run;
ret[retlen++] = '0' + colouring[i];
run = 0;
}
}
if (run > 0)
ret[retlen++] = 'a'-1 + run;
ret[retlen] = '\0';
assert(retlen < retsize);
}
free_scratch(sc);
sfree(regions);
sfree(colouring2);
sfree(colouring);
sfree(graph);
sfree(map);
return ret;
}
static const char *parse_edge_list(const game_params *params,
const char **desc, int *map)
{
int w = params->w, h = params->h, wh = w*h, n = params->n;
int i, k, pos;
bool state;
const char *p = *desc;
const char *err = NULL;
DSF *dsf = dsf_new(wh);
pos = -1;
state = false;
/*
* Parse the game description to get the list of edges, and
* build up a disjoint set forest as we go (by identifying
* pairs of squares whenever the edge list shows a non-edge).
*/
while (*p && *p != ',') {
if (*p < 'a' || *p > 'z') {
err = "Unexpected character in edge list";
goto out;
}
if (*p == 'z')
k = 25;
else
k = *p - 'a' + 1;
while (k-- > 0) {
int x, y, dx, dy;
if (pos < 0) {
pos++;
continue;
} else if (pos < w*(h-1)) {
/* Horizontal edge. */
y = pos / w;
x = pos % w;
dx = 0;
dy = 1;
} else if (pos < 2*wh-w-h) {
/* Vertical edge. */
x = (pos - w*(h-1)) / h;
y = (pos - w*(h-1)) % h;
dx = 1;
dy = 0;
} else {
err = "Too much data in edge list";
goto out;
}
if (!state)
dsf_merge(dsf, y*w+x, (y+dy)*w+(x+dx));
pos++;
}
if (*p != 'z')
state = !state;
p++;
}
assert(pos <= 2*wh-w-h);
if (pos < 2*wh-w-h) {
err = "Too little data in edge list";
goto out;
}
/*
* Now go through again and allocate region numbers.
*/
pos = 0;
for (i = 0; i < wh; i++)
map[i] = -1;
for (i = 0; i < wh; i++) {
k = dsf_canonify(dsf, i);
if (map[k] < 0)
map[k] = pos++;
map[i] = map[k];
}
if (pos != n) {
err = "Edge list defines the wrong number of regions";
goto out;
}
*desc = p;
err = NULL; /* no error */
out:
dsf_free(dsf);
return err;
}
static const char *validate_desc(const game_params *params, const char *desc)
{
int w = params->w, h = params->h, wh = w*h, n = params->n;
int area;
int *map;
const char *ret;
map = snewn(wh, int);
ret = parse_edge_list(params, &desc, map);
sfree(map);
if (ret)
return ret;
if (*desc != ',')
return "Expected comma before clue list";
desc++; /* eat comma */
area = 0;
while (*desc) {
if (*desc >= '0' && *desc < '0'+FOUR)
area++;
else if (*desc >= 'a' && *desc <= 'z')
area += *desc - 'a' + 1;
else
return "Unexpected character in clue list";
desc++;
}
if (area < n)
return "Too little data in clue list";
else if (area > n)
return "Too much data in clue list";
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, n = params->n;
int i, pos;
const char *p;
game_state *state = snew(game_state);
state->p = *params;
state->colouring = snewn(n, int);
for (i = 0; i < n; i++)
state->colouring[i] = -1;
state->pencil = snewn(n, int);
for (i = 0; i < n; i++)
state->pencil[i] = 0;
state->completed = false;
state->cheated = false;
state->map = snew(struct map);
state->map->refcount = 1;
state->map->map = snewn(wh*4, int);
state->map->graph = snewn(n*n, int);
state->map->n = n;
state->map->immutable = snewn(n, bool);
for (i = 0; i < n; i++)
state->map->immutable[i] = false;
p = desc;
{
const char *ret;
ret = parse_edge_list(params, &p, state->map->map);
assert(!ret);
}
/*
* Set up the other three quadrants in `map'.
*/
for (i = wh; i < 4*wh; i++)
state->map->map[i] = state->map->map[i % wh];
assert(*p == ',');
p++;
/*
* Now process the clue list.
*/
pos = 0;
while (*p) {
if (*p >= '0' && *p < '0'+FOUR) {
state->colouring[pos] = *p - '0';
state->map->immutable[pos] = true;
pos++;
} else {
assert(*p >= 'a' && *p <= 'z');
pos += *p - 'a' + 1;
}
p++;
}
assert(pos == n);
state->map->ngraph = gengraph(w, h, n, state->map->map, state->map->graph);
/*
* Attempt to smooth out some of the more jagged region
* outlines by the judicious use of diagonally divided squares.
*/
{
random_state *rs = random_new(desc, strlen(desc));
int *squares = snewn(wh, int);
bool done_something;
for (i = 0; i < wh; i++)
squares[i] = i;
shuffle(squares, wh, sizeof(*squares), rs);
do {
done_something = false;
for (i = 0; i < wh; i++) {
int y = squares[i] / w, x = squares[i] % w;
int c = state->map->map[y*w+x];
int tc, bc, lc, rc;
if (x == 0 || x == w-1 || y == 0 || y == h-1)
continue;
if (state->map->map[TE * wh + y*w+x] !=
state->map->map[BE * wh + y*w+x])
continue;
tc = state->map->map[BE * wh + (y-1)*w+x];
bc = state->map->map[TE * wh + (y+1)*w+x];
lc = state->map->map[RE * wh + y*w+(x-1)];
rc = state->map->map[LE * wh + y*w+(x+1)];
/*
* If this square is adjacent on two sides to one
* region and on the other two sides to the other
* region, and is itself one of the two regions, we can
* adjust it so that it's a diagonal.
*/
if (tc != bc && (tc == c || bc == c)) {
if ((lc == tc && rc == bc) ||
(lc == bc && rc == tc)) {
state->map->map[TE * wh + y*w+x] = tc;
state->map->map[BE * wh + y*w+x] = bc;
state->map->map[LE * wh + y*w+x] = lc;
state->map->map[RE * wh + y*w+x] = rc;
done_something = true;
}
}
}
} while (done_something);
sfree(squares);
random_free(rs);
}
/*
* Analyse the map to find a canonical line segment
* corresponding to each edge, and a canonical point
* corresponding to each region. The former are where we'll
* eventually put error markers; the latter are where we'll put
* per-region flags such as numbers (when in diagnostic mode).
*/
{
int *bestx, *besty, *an, pass;
float *ax, *ay, *best;
ax = snewn(state->map->ngraph + n, float);
ay = snewn(state->map->ngraph + n, float);
an = snewn(state->map->ngraph + n, int);
bestx = snewn(state->map->ngraph + n, int);
besty = snewn(state->map->ngraph + n, int);
best = snewn(state->map->ngraph + n, float);
for (i = 0; i < state->map->ngraph + n; i++) {
bestx[i] = besty[i] = -1;
best[i] = (float)(2*(w+h)+1);
ax[i] = ay[i] = 0.0F;
an[i] = 0;
}
/*
* We make two passes over the map, finding all the line
* segments separating regions and all the suitable points
* within regions. In the first pass, we compute the
* _average_ x and y coordinate of all the points in a
* given class; in the second pass, for each such average
* point, we find the candidate closest to it and call that
* canonical.
*
* Line segments are considered to have coordinates in
* their centre. Thus, at least one coordinate for any line
* segment is always something-and-a-half; so we store our
* coordinates as twice their normal value.
*/
for (pass = 0; pass < 2; pass++) {
int x, y;
for (y = 0; y < h; y++)
for (x = 0; x < w; x++) {
int ex[4], ey[4], ea[4], eb[4], en = 0;
/*
* Look for an edge to the right of this
* square, an edge below it, and an edge in the
* middle of it. Also look to see if the point
* at the bottom right of this square is on an
* edge (and isn't a place where more than two
* regions meet).
*/
if (x+1 < w) {
/* right edge */
ea[en] = state->map->map[RE * wh + y*w+x];
eb[en] = state->map->map[LE * wh + y*w+(x+1)];
ex[en] = (x+1)*2;
ey[en] = y*2+1;
en++;
}
if (y+1 < h) {
/* bottom edge */
ea[en] = state->map->map[BE * wh + y*w+x];
eb[en] = state->map->map[TE * wh + (y+1)*w+x];
ex[en] = x*2+1;
ey[en] = (y+1)*2;
en++;
}
/* diagonal edge */
ea[en] = state->map->map[TE * wh + y*w+x];
eb[en] = state->map->map[BE * wh + y*w+x];
ex[en] = x*2+1;
ey[en] = y*2+1;
en++;
if (x+1 < w && y+1 < h) {
/* bottom right corner */
int oct[8], othercol, nchanges;
oct[0] = state->map->map[RE * wh + y*w+x];
oct[1] = state->map->map[LE * wh + y*w+(x+1)];
oct[2] = state->map->map[BE * wh + y*w+(x+1)];
oct[3] = state->map->map[TE * wh + (y+1)*w+(x+1)];
oct[4] = state->map->map[LE * wh + (y+1)*w+(x+1)];
oct[5] = state->map->map[RE * wh + (y+1)*w+x];
oct[6] = state->map->map[TE * wh + (y+1)*w+x];
oct[7] = state->map->map[BE * wh + y*w+x];
othercol = -1;
nchanges = 0;
for (i = 0; i < 8; i++) {
if (oct[i] != oct[0]) {
if (othercol < 0)
othercol = oct[i];
else if (othercol != oct[i])
break; /* three colours at this point */
}
if (oct[i] != oct[(i+1) & 7])
nchanges++;
}
/*
* Now if there are exactly two regions at
* this point (not one, and not three or
* more), and only two changes around the
* loop, then this is a valid place to put
* an error marker.
*/
if (i == 8 && othercol >= 0 && nchanges == 2) {
ea[en] = oct[0];
eb[en] = othercol;
ex[en] = (x+1)*2;
ey[en] = (y+1)*2;
en++;
}
/*
* If there's exactly _one_ region at this
* point, on the other hand, it's a valid
* place to put a region centre.
*/
if (othercol < 0) {
ea[en] = eb[en] = oct[0];
ex[en] = (x+1)*2;
ey[en] = (y+1)*2;
en++;
}
}
/*
* Now process the points we've found, one by
* one.
*/
for (i = 0; i < en; i++) {
int emin = min(ea[i], eb[i]);
int emax = max(ea[i], eb[i]);
int gindex;
if (emin != emax) {
/* Graph edge */
gindex =
graph_edge_index(state->map->graph, n,
state->map->ngraph, emin,
emax);
} else {
/* Region number */
gindex = state->map->ngraph + emin;
}
assert(gindex >= 0);
if (pass == 0) {
/*
* In pass 0, accumulate the values
* we'll use to compute the average
* positions.
*/
ax[gindex] += ex[i];
ay[gindex] += ey[i];
an[gindex] += 1;
} else {
/*
* In pass 1, work out whether this
* point is closer to the average than
* the last one we've seen.
*/
float dx, dy, d;
assert(an[gindex] > 0);
dx = ex[i] - ax[gindex];
dy = ey[i] - ay[gindex];
d = (float)sqrt(dx*dx + dy*dy);
if (d < best[gindex]) {
best[gindex] = d;
bestx[gindex] = ex[i];
besty[gindex] = ey[i];
}
}
}
}
if (pass == 0) {
for (i = 0; i < state->map->ngraph + n; i++)
if (an[i] > 0) {
ax[i] /= an[i];
ay[i] /= an[i];
}
}
}
state->map->edgex = snewn(state->map->ngraph, int);
state->map->edgey = snewn(state->map->ngraph, int);
memcpy(state->map->edgex, bestx, state->map->ngraph * sizeof(int));
memcpy(state->map->edgey, besty, state->map->ngraph * sizeof(int));
state->map->regionx = snewn(n, int);
state->map->regiony = snewn(n, int);
memcpy(state->map->regionx, bestx + state->map->ngraph, n*sizeof(int));
memcpy(state->map->regiony, besty + state->map->ngraph, n*sizeof(int));
for (i = 0; i < state->map->ngraph; i++)
if (state->map->edgex[i] < 0) {
/* Find the other representation of this edge. */
int e = state->map->graph[i];
int iprime = graph_edge_index(state->map->graph, n,
state->map->ngraph, e%n, e/n);
assert(state->map->edgex[iprime] >= 0);
state->map->edgex[i] = state->map->edgex[iprime];
state->map->edgey[i] = state->map->edgey[iprime];
}
sfree(ax);
sfree(ay);
sfree(an);
sfree(best);
sfree(bestx);
sfree(besty);
}
return state;
}
static game_state *dup_game(const game_state *state)
{
game_state *ret = snew(game_state);
ret->p = state->p;
ret->colouring = snewn(state->p.n, int);
memcpy(ret->colouring, state->colouring, state->p.n * sizeof(int));
ret->pencil = snewn(state->p.n, int);
memcpy(ret->pencil, state->pencil, state->p.n * sizeof(int));
ret->map = state->map;
ret->map->refcount++;
ret->completed = state->completed;
ret->cheated = state->cheated;
return ret;
}
static void free_game(game_state *state)
{
if (--state->map->refcount <= 0) {
sfree(state->map->map);
sfree(state->map->graph);
sfree(state->map->immutable);
sfree(state->map->edgex);
sfree(state->map->edgey);
sfree(state->map->regionx);
sfree(state->map->regiony);
sfree(state->map);
}
sfree(state->pencil);
sfree(state->colouring);
sfree(state);
}
static char *solve_game(const game_state *state, const game_state *currstate,
const char *aux, const char **error)
{
if (!aux) {
/*
* Use the solver.
*/
int *colouring;
struct solver_scratch *sc;
int sret;
int i;
char *ret, buf[80];
int retlen, retsize;
colouring = snewn(state->map->n, int);
memcpy(colouring, state->colouring, state->map->n * sizeof(int));
sc = new_scratch(state->map->graph, state->map->n, state->map->ngraph);
sret = map_solver(sc, state->map->graph, state->map->n,
state->map->ngraph, colouring, DIFFCOUNT-1);
free_scratch(sc);
if (sret != 1) {
sfree(colouring);
if (sret == 0)
*error = "Puzzle is inconsistent";
else
*error = "Unable to find a unique solution for this puzzle";
return NULL;
}
retsize = 64;
ret = snewn(retsize, char);
strcpy(ret, "S");
retlen = 1;
for (i = 0; i < state->map->n; i++) {
int len;
assert(colouring[i] >= 0);
if (colouring[i] == currstate->colouring[i])
continue;
assert(!state->map->immutable[i]);
len = sprintf(buf, ";%d:%d", colouring[i], i);
if (retlen + len >= retsize) {
retsize = retlen + len + 256;
ret = sresize(ret, retsize, char);
}
strcpy(ret + retlen, buf);
retlen += len;
}
sfree(colouring);
return ret;
}
return dupstr(aux);
}
struct game_ui {
/*
* drag_colour:
*
* - -2 means no drag currently active.
* - >=0 means we're dragging a solid colour.
* - -1 means we're dragging a blank space, and drag_pencil
* might or might not add some pencil-mark stipples to that.
*/
int drag_colour;
int drag_pencil;
int dragx, dragy;
bool show_numbers;
int cur_x, cur_y, cur_lastmove;
bool cur_visible, cur_moved;
/*
* User preference to enable alternative versions of the
* completion flash. Some users have found the colour-cycling
* default version to be a bit eye-twisting.
*/
enum {
FLASH_CYCLIC, /* cycle the four colours of the map */
FLASH_EACH_TO_WHITE, /* turn each colour white in turn */
FLASH_ALL_TO_WHITE /* flash the whole map to white in one go */
} flash_type;
};
static void legacy_prefs_override(struct game_ui *ui_out)
{
static bool initialised = false;
static int flash_type = -1;
if (!initialised) {
char *env;
initialised = true;
if ((env = getenv("MAP_ALTERNATIVE_FLASH")) != NULL)
flash_type = FLASH_EACH_TO_WHITE;
}
if (flash_type != -1)
ui_out->flash_type = flash_type;
}
static game_ui *new_ui(const game_state *state)
{
game_ui *ui = snew(game_ui);
ui->dragx = ui->dragy = -1;
ui->drag_colour = -2;
ui->drag_pencil = 0;
ui->show_numbers = false;
ui->cur_x = ui->cur_y = 0;
ui->cur_visible = getenv_bool("PUZZLES_SHOW_CURSOR", false);
ui->cur_moved = false;
ui->cur_lastmove = 0;
ui->flash_type = FLASH_CYCLIC;
legacy_prefs_override(ui);
return ui;
}
static config_item *get_prefs(game_ui *ui)
{
config_item *ret;
ret = snewn(3, config_item);
ret[0].name = "Victory flash effect";
ret[0].kw = "flash-type";
ret[0].type = C_CHOICES;
ret[0].u.choices.choicenames = ":Cyclic:Each to white:All to white";
ret[0].u.choices.choicekws = ":cyclic:each-white:all-white";
ret[0].u.choices.selected = ui->flash_type;
ret[1].name = "Number regions";
ret[1].kw = "show-numbers";
ret[1].type = C_BOOLEAN;
ret[1].u.boolean.bval = ui->show_numbers;
ret[2].name = NULL;
ret[2].type = C_END;
return ret;
}
static void set_prefs(game_ui *ui, const config_item *cfg)
{
ui->flash_type = cfg[0].u.choices.selected;
ui->show_numbers = cfg[1].u.boolean.bval;
}
static void free_ui(game_ui *ui)
{
sfree(ui);
}
static void game_changed_state(game_ui *ui, const game_state *oldstate,
const game_state *newstate)
{
}
struct game_drawstate {
int tilesize;
unsigned long *drawn, *todraw;
bool started;
int dragx, dragy;
bool drag_visible;
blitter *bl;
};
/* Flags in `drawn'. */
#define ERR_BASE 0x00800000L
#define ERR_MASK 0xFF800000L
#define PENCIL_T_BASE 0x00080000L
#define PENCIL_T_MASK 0x00780000L
#define PENCIL_B_BASE 0x00008000L
#define PENCIL_B_MASK 0x00078000L
#define PENCIL_MASK 0x007F8000L
#define SHOW_NUMBERS 0x00004000L
#define TILESIZE (ds->tilesize)
#define BORDER (TILESIZE)
#define COORD(x) ( (x) * TILESIZE + BORDER )
#define FROMCOORD(x) ( ((x) - BORDER + TILESIZE) / TILESIZE - 1 )
/*
* EPSILON_FOO are epsilons added to absolute cursor position by
* cursor movement, such that in pathological cases (e.g. a very
* small diamond-shaped area) it's relatively easy to select the
* region you wanted.
*/
#define EPSILON_X(button) (((button) == CURSOR_RIGHT) ? +1 : \
((button) == CURSOR_LEFT) ? -1 : 0)
#define EPSILON_Y(button) (((button) == CURSOR_DOWN) ? +1 : \
((button) == CURSOR_UP) ? -1 : 0)
/*
* Return the map region containing a point in tile (tx,ty), offset by
* (x_eps,y_eps) from the centre of the tile.
*/
static int region_from_logical_coords(const game_state *state, int tx, int ty,
int x_eps, int y_eps)
{
int w = state->p.w, h = state->p.h, wh = w*h /*, n = state->p.n */;
int quadrant;
if (tx < 0 || tx >= w || ty < 0 || ty >= h)
return -1; /* border */
quadrant = 2 * (x_eps > y_eps) + (-x_eps > y_eps);
quadrant = (quadrant == 0 ? BE :
quadrant == 1 ? LE :
quadrant == 2 ? RE : TE);
return state->map->map[quadrant * wh + ty*w+tx];
}
static int region_from_coords(const game_state *state,
const game_drawstate *ds, int x, int y)
{
int tx = FROMCOORD(x), ty = FROMCOORD(y);
return region_from_logical_coords(
state, tx, ty, x - COORD(tx) - TILESIZE/2, y - COORD(ty) - TILESIZE/2);
}
static int region_from_ui_cursor(const game_state *state, const game_ui *ui)
{
assert(ui->cur_visible);
return region_from_logical_coords(state, ui->cur_x, ui->cur_y,
EPSILON_X(ui->cur_lastmove),
EPSILON_Y(ui->cur_lastmove));
}
static const char *current_key_label(const game_ui *ui,
const game_state *state, int button)
{
int r;
if (IS_CURSOR_SELECT(button) && ui->cur_visible) {
if (ui->drag_colour == -2) return "Pick";
r = region_from_ui_cursor(state, ui);
if (state->map->immutable[r]) return "Cancel";
if (!ui->cur_moved) return ui->drag_pencil ? "Cancel" : "Clear";
if (button == CURSOR_SELECT2) {
if (state->colouring[r] >= 0) return "Cancel";
if (ui->drag_colour >= 0) return "Stipple";
}
if (ui->drag_pencil) return "Stipple";
return ui->drag_colour >= 0 ? "Fill" : "Clear";
}
return "";
}
static char *interpret_move(const game_state *state, game_ui *ui,
const game_drawstate *ds,
int x, int y, int button)
{
char *bufp, buf[256];
bool alt_button;
int drop_region;
/*
* Enable or disable numeric labels on regions.
*/
if (button == 'l' || button == 'L') {
ui->show_numbers = !ui->show_numbers;
return MOVE_UI_UPDATE;
}
if (IS_CURSOR_MOVE(button)) {
move_cursor(button, &ui->cur_x, &ui->cur_y, state->p.w, state->p.h,
false);
ui->cur_visible = true;
ui->cur_moved = true;
ui->cur_lastmove = button;
return MOVE_UI_UPDATE;
}
if (IS_CURSOR_SELECT(button)) {
if (!ui->cur_visible) {
ui->cur_visible = true;
return MOVE_UI_UPDATE;
}
if (ui->drag_colour == -2) { /* not currently cursor-dragging, start. */
int r = region_from_ui_cursor(state, ui);
if (r >= 0) {
ui->drag_colour = state->colouring[r];
ui->drag_pencil = (ui->drag_colour >= 0) ? 0 : state->pencil[r];
} else {
ui->drag_colour = -1;
ui->drag_pencil = 0;
}
ui->cur_moved = false;
return MOVE_UI_UPDATE;
} else { /* currently cursor-dragging; drop the colour in the new region. */
alt_button = (button == CURSOR_SELECT2);
/* Double-select removes current colour. */
if (!ui->cur_moved) ui->drag_colour = -1;
drop_region = region_from_ui_cursor(state, ui);
goto drag_dropped;
}
}
if (button == LEFT_BUTTON || button == RIGHT_BUTTON) {
int r = region_from_coords(state, ds, x, y);
if (r >= 0) {
ui->drag_colour = state->colouring[r];
ui->drag_pencil = state->pencil[r];
if (ui->drag_colour >= 0)
ui->drag_pencil = 0; /* should be already, but double-check */
} else {
ui->drag_colour = -1;
ui->drag_pencil = 0;
}
ui->dragx = x;
ui->dragy = y;
ui->cur_visible = false;
return MOVE_UI_UPDATE;
}
if ((button == LEFT_DRAG || button == RIGHT_DRAG) &&
ui->drag_colour > -2) {
ui->dragx = x;
ui->dragy = y;
return MOVE_UI_UPDATE;
}
if ((button == LEFT_RELEASE || button == RIGHT_RELEASE) &&
ui->drag_colour > -2) {
alt_button = (button == RIGHT_RELEASE);
drop_region = region_from_coords(state, ds, x, y);
goto drag_dropped;
}
return NULL;
drag_dropped:
{
int r = drop_region;
int c = ui->drag_colour;
int p = ui->drag_pencil;
int oldp;
/*
* Cancel the drag, whatever happens.
*/
ui->drag_colour = -2;
if (r < 0)
return MOVE_UI_UPDATE; /* drag into border; do nothing else */
if (state->map->immutable[r])
return MOVE_UI_UPDATE; /* can't change this region */
if (state->colouring[r] == c && state->pencil[r] == p)
return MOVE_UI_UPDATE; /* don't _need_ to change this region */
if (alt_button) {
if (state->colouring[r] >= 0) {
/* Can't pencil on a coloured region */
return MOVE_UI_UPDATE;
} else if (c >= 0) {
/* Right-dragging from colour to blank toggles one pencil */
p = state->pencil[r] ^ (1 << c);
c = -1;
}
/* Otherwise, right-dragging from blank to blank is equivalent
* to left-dragging. */
}
bufp = buf;
oldp = state->pencil[r];
if (c != state->colouring[r]) {
bufp += sprintf(bufp, ";%c:%d", (int)(c < 0 ? 'C' : '0' + c), r);
if (c >= 0)
oldp = 0;
}
if (p != oldp) {
int i;
for (i = 0; i < FOUR; i++)
if ((oldp ^ p) & (1 << i))
bufp += sprintf(bufp, ";p%c:%d", (int)('0' + i), r);
}
return dupstr(buf+1); /* ignore first semicolon */
}
}
static game_state *execute_move(const game_state *state, const char *move)
{
int n = state->p.n;
game_state *ret = dup_game(state);
int c, k, adv, i;
while (*move) {
bool pencil = false;
c = *move;
if (c == 'p') {
pencil = true;
c = *++move;
}
if ((c == 'C' || (c >= '0' && c < '0'+FOUR)) &&
sscanf(move+1, ":%d%n", &k, &adv) == 1 &&
k >= 0 && k < state->p.n) {
move += 1 + adv;
if (pencil) {
if (ret->colouring[k] >= 0) {
free_game(ret);
return NULL;
}
if (c == 'C')
ret->pencil[k] = 0;
else
ret->pencil[k] ^= 1 << (c - '0');
} else {
ret->colouring[k] = (c == 'C' ? -1 : c - '0');
ret->pencil[k] = 0;
}
} else if (*move == 'S') {
move++;
ret->cheated = true;
} else {
free_game(ret);
return NULL;
}
if (*move && *move != ';') {
free_game(ret);
return NULL;
}
if (*move)
move++;
}
/*
* Check for completion.
*/
if (!ret->completed) {
bool ok = true;
for (i = 0; i < n; i++)
if (ret->colouring[i] < 0) {
ok = false;
break;
}
if (ok) {
for (i = 0; i < ret->map->ngraph; i++) {
int j = ret->map->graph[i] / n;
int k = ret->map->graph[i] % n;
if (ret->colouring[j] == ret->colouring[k]) {
ok = false;
break;
}
}
}
if (ok)
ret->completed = true;
}
return ret;
}
/* ----------------------------------------------------------------------
* Drawing routines.
*/
static void game_compute_size(const game_params *params, int tilesize,
const game_ui *ui, int *x, int *y)
{
/* Ick: fake up `ds->tilesize' for macro expansion purposes */
struct { int tilesize; } ads, *ds = &ads;
ads.tilesize = tilesize;
*x = params->w * TILESIZE + 2 * BORDER + 1;
*y = params->h * TILESIZE + 2 * BORDER + 1;
}
static void game_set_size(drawing *dr, game_drawstate *ds,
const game_params *params, int tilesize)
{
ds->tilesize = tilesize;
assert(!ds->bl); /* set_size is never called twice */
ds->bl = blitter_new(dr, TILESIZE+3, TILESIZE+3);
}
static const float map_colours[FOUR][3] = {
#ifdef VIVID_COLOURS
/* Use more vivid colours (e.g. on the Pocket PC) */
{0.75F, 0.25F, 0.25F},
{0.3F, 0.7F, 0.3F},
{0.3F, 0.3F, 0.7F},
{0.85F, 0.85F, 0.1F},
#else
{0.7F, 0.5F, 0.4F},
{0.8F, 0.7F, 0.4F},
{0.5F, 0.6F, 0.4F},
{0.55F, 0.45F, 0.35F},
#endif
};
static const int map_hatching[FOUR] = {
HATCH_VERT, HATCH_SLASH, HATCH_HORIZ, HATCH_BACKSLASH
};
static float *game_colours(frontend *fe, int *ncolours)
{
float *ret = snewn(3 * NCOLOURS, float);
frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
ret[COL_GRID * 3 + 0] = 0.0F;
ret[COL_GRID * 3 + 1] = 0.0F;
ret[COL_GRID * 3 + 2] = 0.0F;
memcpy(ret + COL_0 * 3, map_colours[0], 3 * sizeof(float));
memcpy(ret + COL_1 * 3, map_colours[1], 3 * sizeof(float));
memcpy(ret + COL_2 * 3, map_colours[2], 3 * sizeof(float));
memcpy(ret + COL_3 * 3, map_colours[3], 3 * sizeof(float));
ret[COL_ERROR * 3 + 0] = 1.0F;
ret[COL_ERROR * 3 + 1] = 0.0F;
ret[COL_ERROR * 3 + 2] = 0.0F;
ret[COL_ERRTEXT * 3 + 0] = 1.0F;
ret[COL_ERRTEXT * 3 + 1] = 1.0F;
ret[COL_ERRTEXT * 3 + 2] = 1.0F;
*ncolours = NCOLOURS;
return ret;
}
static game_drawstate *game_new_drawstate(drawing *dr, const game_state *state)
{
struct game_drawstate *ds = snew(struct game_drawstate);
int i;
ds->tilesize = 0;
ds->drawn = snewn(state->p.w * state->p.h, unsigned long);
for (i = 0; i < state->p.w * state->p.h; i++)
ds->drawn[i] = 0xFFFFL;
ds->todraw = snewn(state->p.w * state->p.h, unsigned long);
ds->started = false;
ds->bl = NULL;
ds->drag_visible = false;
ds->dragx = ds->dragy = -1;
return ds;
}
static void game_free_drawstate(drawing *dr, game_drawstate *ds)
{
sfree(ds->drawn);
sfree(ds->todraw);
if (ds->bl)
blitter_free(dr, ds->bl);
sfree(ds);
}
static void draw_error(drawing *dr, game_drawstate *ds, int x, int y)
{
int coords[8];
int yext, xext;
/*
* Draw a diamond.
*/
coords[0] = x - TILESIZE*2/5;
coords[1] = y;
coords[2] = x;
coords[3] = y - TILESIZE*2/5;
coords[4] = x + TILESIZE*2/5;
coords[5] = y;
coords[6] = x;
coords[7] = y + TILESIZE*2/5;
draw_polygon(dr, coords, 4, COL_ERROR, COL_GRID);
/*
* Draw an exclamation mark in the diamond. This turns out to
* look unpleasantly off-centre if done via draw_text, so I do
* it by hand on the basis that exclamation marks aren't that
* difficult to draw...
*/
xext = TILESIZE/16;
yext = TILESIZE*2/5 - (xext*2+2);
draw_rect(dr, x-xext, y-yext, xext*2+1, yext*2+1 - (xext*3),
COL_ERRTEXT);
draw_rect(dr, x-xext, y+yext-xext*2+1, xext*2+1, xext*2, COL_ERRTEXT);
}
static void draw_square(drawing *dr, game_drawstate *ds,
const game_params *params, struct map *map,
int x, int y, unsigned long v)
{
int w = params->w, h = params->h, wh = w*h;
int tv, bv, xo, yo, i, j, oldj;
unsigned long errs, pencil, show_numbers;
errs = v & ERR_MASK;
v &= ~ERR_MASK;
pencil = v & PENCIL_MASK;
v &= ~PENCIL_MASK;
show_numbers = v & SHOW_NUMBERS;
v &= ~SHOW_NUMBERS;
tv = v / FIVE;
bv = v % FIVE;
clip(dr, COORD(x), COORD(y), TILESIZE, TILESIZE);
/*
* Draw the region colour.
*/
draw_rect(dr, COORD(x), COORD(y), TILESIZE, TILESIZE,
(tv == FOUR ? COL_BACKGROUND : COL_0 + tv));
/*
* Draw the second region colour, if this is a diagonally
* divided square.
*/
if (map->map[TE * wh + y*w+x] != map->map[BE * wh + y*w+x]) {
int coords[6];
coords[0] = COORD(x)-1;
coords[1] = COORD(y+1)+1;
if (map->map[LE * wh + y*w+x] == map->map[TE * wh + y*w+x])
coords[2] = COORD(x+1)+1;
else
coords[2] = COORD(x)-1;
coords[3] = COORD(y)-1;
coords[4] = COORD(x+1)+1;
coords[5] = COORD(y+1)+1;
draw_polygon(dr, coords, 3,
(bv == FOUR ? COL_BACKGROUND : COL_0 + bv), COL_GRID);
}
/*
* Draw `pencil marks'. Currently we arrange these in a square
* formation, which means we may be in trouble if the value of
* FOUR changes later...
*/
assert(FOUR == 4);
for (yo = 0; yo < 4; yo++)
for (xo = 0; xo < 4; xo++) {
int te = map->map[TE * wh + y*w+x];
int e, ee, c;
e = (yo < xo && yo < 3-xo ? TE :
yo > xo && yo > 3-xo ? BE :
xo < 2 ? LE : RE);
ee = map->map[e * wh + y*w+x];
if (xo != (yo * 2 + 1) % 5)
continue;
c = yo;
if (!(pencil & ((ee == te ? PENCIL_T_BASE : PENCIL_B_BASE) << c)))
continue;
if (yo == xo &&
(map->map[TE * wh + y*w+x] != map->map[LE * wh + y*w+x]))
continue; /* avoid TL-BR diagonal line */
if (yo == 3-xo &&
(map->map[TE * wh + y*w+x] != map->map[RE * wh + y*w+x]))
continue; /* avoid BL-TR diagonal line */
draw_circle(dr, COORD(x) + (xo+1)*TILESIZE/5,
COORD(y) + (yo+1)*TILESIZE/5,
TILESIZE/7, COL_0 + c, COL_0 + c);
}
/*
* Draw the grid lines, if required.
*/
if (x <= 0 || map->map[RE*wh+y*w+(x-1)] != map->map[LE*wh+y*w+x])
draw_rect(dr, COORD(x), COORD(y), 1, TILESIZE, COL_GRID);
if (y <= 0 || map->map[BE*wh+(y-1)*w+x] != map->map[TE*wh+y*w+x])
draw_rect(dr, COORD(x), COORD(y), TILESIZE, 1, COL_GRID);
if (x <= 0 || y <= 0 ||
map->map[RE*wh+(y-1)*w+(x-1)] != map->map[TE*wh+y*w+x] ||
map->map[BE*wh+(y-1)*w+(x-1)] != map->map[LE*wh+y*w+x])
draw_rect(dr, COORD(x), COORD(y), 1, 1, COL_GRID);
/*
* Draw error markers.
*/
for (yo = 0; yo < 3; yo++)
for (xo = 0; xo < 3; xo++)
if (errs & (ERR_BASE << (yo*3+xo)))
draw_error(dr, ds,
(COORD(x)*2+TILESIZE*xo)/2,
(COORD(y)*2+TILESIZE*yo)/2);
/*
* Draw region numbers, if desired.
*/
if (show_numbers) {
oldj = -1;
for (i = 0; i < 2; i++) {
j = map->map[(i?BE:TE)*wh+y*w+x];
if (oldj == j)
continue;
oldj = j;
xo = map->regionx[j] - 2*x;
yo = map->regiony[j] - 2*y;
if (xo >= 0 && xo <= 2 && yo >= 0 && yo <= 2) {
char buf[80];
sprintf(buf, "%d", j);
draw_text(dr, (COORD(x)*2+TILESIZE*xo)/2,
(COORD(y)*2+TILESIZE*yo)/2,
FONT_VARIABLE, 3*TILESIZE/5,
ALIGN_HCENTRE|ALIGN_VCENTRE,
COL_GRID, buf);
}
}
}
unclip(dr);
draw_update(dr, COORD(x), COORD(y), TILESIZE, TILESIZE);
}
static float flash_length(const game_ui *ui)
{
return (ui->flash_type == FLASH_EACH_TO_WHITE ? 0.50F : 0.30F);
}
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 w = state->p.w, h = state->p.h, wh = w*h, n = state->p.n;
int x, y, i;
int flash;
if (ds->drag_visible) {
blitter_load(dr, ds->bl, ds->dragx, ds->dragy);
draw_update(dr, ds->dragx, ds->dragy, TILESIZE + 3, TILESIZE + 3);
ds->drag_visible = false;
}
if (!ds->started) {
draw_rect(dr, COORD(0), COORD(0), w*TILESIZE+1, h*TILESIZE+1,
COL_GRID);
draw_update(dr, COORD(0), COORD(0), w*TILESIZE+1, h*TILESIZE+1);
ds->started = true;
}
if (flashtime) {
if (ui->flash_type == FLASH_EACH_TO_WHITE)
flash = (int)(flashtime * FOUR / flash_length(ui));
else
flash = 1 + (int)(flashtime * THREE / flash_length(ui));
} else
flash = -1;
/*
* Set up the `todraw' array.
*/
for (y = 0; y < h; y++)
for (x = 0; x < w; x++) {
int tv = state->colouring[state->map->map[TE * wh + y*w+x]];
int bv = state->colouring[state->map->map[BE * wh + y*w+x]];
unsigned long v;
if (tv < 0)
tv = FOUR;
if (bv < 0)
bv = FOUR;
if (flash >= 0) {
if (ui->flash_type == FLASH_EACH_TO_WHITE) {
if (tv == flash)
tv = FOUR;
if (bv == flash)
bv = FOUR;
} else if (ui->flash_type == FLASH_ALL_TO_WHITE) {
if (flash % 2)
tv = bv = FOUR;
} else {
if (tv != FOUR)
tv = (tv + flash) % FOUR;
if (bv != FOUR)
bv = (bv + flash) % FOUR;
}
}
v = tv * FIVE + bv;
/*
* Add pencil marks.
*/
for (i = 0; i < FOUR; i++) {
if (state->colouring[state->map->map[TE * wh + y*w+x]] < 0 &&
(state->pencil[state->map->map[TE * wh + y*w+x]] & (1<<i)))
v |= PENCIL_T_BASE << i;
if (state->colouring[state->map->map[BE * wh + y*w+x]] < 0 &&
(state->pencil[state->map->map[BE * wh + y*w+x]] & (1<<i)))
v |= PENCIL_B_BASE << i;
}
if (ui->show_numbers)
v |= SHOW_NUMBERS;
ds->todraw[y*w+x] = v;
}
/*
* Add error markers to the `todraw' array.
*/
for (i = 0; i < state->map->ngraph; i++) {
int v1 = state->map->graph[i] / n;
int v2 = state->map->graph[i] % n;
int xo, yo;
if (state->colouring[v1] < 0 || state->colouring[v2] < 0)
continue;
if (state->colouring[v1] != state->colouring[v2])
continue;
x = state->map->edgex[i];
y = state->map->edgey[i];
xo = x % 2; x /= 2;
yo = y % 2; y /= 2;
ds->todraw[y*w+x] |= ERR_BASE << (yo*3+xo);
if (xo == 0) {
assert(x > 0);
ds->todraw[y*w+(x-1)] |= ERR_BASE << (yo*3+2);
}
if (yo == 0) {
assert(y > 0);
ds->todraw[(y-1)*w+x] |= ERR_BASE << (2*3+xo);
}
if (xo == 0 && yo == 0) {
assert(x > 0 && y > 0);
ds->todraw[(y-1)*w+(x-1)] |= ERR_BASE << (2*3+2);
}
}
/*
* Now actually draw everything.
*/
for (y = 0; y < h; y++)
for (x = 0; x < w; x++) {
unsigned long v = ds->todraw[y*w+x];
if (ds->drawn[y*w+x] != v) {
draw_square(dr, ds, &state->p, state->map, x, y, v);
ds->drawn[y*w+x] = v;
}
}
/*
* Draw the dragged colour blob if any.
*/
if ((ui->drag_colour > -2) || ui->cur_visible) {
int bg, cursor_x, cursor_y;
bool iscur = false;
if (ui->drag_colour >= 0)
bg = COL_0 + ui->drag_colour;
else if (ui->drag_colour == -1) {
bg = COL_BACKGROUND;
} else {
int r = region_from_ui_cursor(state, ui);
int c = (r < 0) ? -1 : state->colouring[r];
/*bg = COL_GRID;*/
bg = (c < 0) ? COL_BACKGROUND : COL_0 + c;
iscur = true;
}
if (ui->cur_visible) {
cursor_x = COORD(ui->cur_x) + TILESIZE/2 +
EPSILON_X(ui->cur_lastmove);
cursor_y = COORD(ui->cur_y) + TILESIZE/2 +
EPSILON_Y(ui->cur_lastmove);
} else {
cursor_x = ui->dragx;
cursor_y = ui->dragy;
}
ds->dragx = cursor_x - TILESIZE/2 - 2;
ds->dragy = cursor_y - TILESIZE/2 - 2;
blitter_save(dr, ds->bl, ds->dragx, ds->dragy);
draw_circle(dr, cursor_x, cursor_y,
iscur ? TILESIZE/4 : TILESIZE/2, bg, COL_GRID);
for (i = 0; i < FOUR; i++)
if (ui->drag_pencil & (1 << i))
draw_circle(dr, cursor_x + ((i*4+2)%10-3) * TILESIZE/10,
cursor_y + (i*2-3) * TILESIZE/10,
TILESIZE/8, COL_0 + i, COL_0 + i);
draw_update(dr, ds->dragx, ds->dragy, TILESIZE + 3, TILESIZE + 3);
ds->drag_visible = true;
}
}
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_length(ui);
} else
return 0.0F;
}
static void game_get_cursor_location(const game_ui *ui,
const game_drawstate *ds,
const game_state *state,
const game_params *params,
int *x, int *y, int *w, int *h)
{
if(ui->cur_visible) {
*x = COORD(ui->cur_x);
*y = COORD(ui->cur_y);
*w = *h = TILESIZE;
}
}
static int game_status(const game_state *state)
{
return state->completed ? +1 : 0;
}
static void game_print_size(const game_params *params, const game_ui *ui,
float *x, float *y)
{
int pw, ph;
/*
* I'll use 4mm squares by default, I think. Simplest way to
* compute this size is to compute the pixel puzzle size at a
* given tile size and then scale.
*/
game_compute_size(params, 400, ui, &pw, &ph);
*x = pw / 100.0F;
*y = ph / 100.0F;
}
static void game_print(drawing *dr, const game_state *state, const game_ui *ui,
int tilesize)
{
int w = state->p.w, h = state->p.h, wh = w*h, n = state->p.n;
int ink, c[FOUR], i;
int x, y, r;
int *coords, ncoords, coordsize;
/* Ick: fake up `ds->tilesize' for macro expansion purposes */
struct { int tilesize; } ads, *ds = &ads;
/* We can't call game_set_size() here because we don't want a blitter */
ads.tilesize = tilesize;
ink = print_mono_colour(dr, 0);
for (i = 0; i < FOUR; i++)
c[i] = print_rgb_hatched_colour(dr, map_colours[i][0],
map_colours[i][1], map_colours[i][2],
map_hatching[i]);
coordsize = 0;
coords = NULL;
print_line_width(dr, TILESIZE / 16);
/*
* Draw a single filled polygon around each region.
*/
for (r = 0; r < n; r++) {
int octants[8], lastdir, d1, d2, ox, oy;
/*
* Start by finding a point on the region boundary. Any
* point will do. To do this, we'll search for a square
* containing the region and then decide which corner of it
* to use.
*/
x = w;
for (y = 0; y < h; y++) {
for (x = 0; x < w; x++) {
if (state->map->map[wh*0+y*w+x] == r ||
state->map->map[wh*1+y*w+x] == r ||
state->map->map[wh*2+y*w+x] == r ||
state->map->map[wh*3+y*w+x] == r)
break;
}
if (x < w)
break;
}
assert(y < h && x < w); /* we must have found one somewhere */
/*
* This is the first square in lexicographic order which
* contains part of this region. Therefore, one of the top
* two corners of the square must be what we're after. The
* only case in which it isn't the top left one is if the
* square is diagonally divided and the region is in the
* bottom right half.
*/
if (state->map->map[wh*TE+y*w+x] != r &&
state->map->map[wh*LE+y*w+x] != r)
x++; /* could just as well have done y++ */
/*
* Now we have a point on the region boundary. Trace around
* the region until we come back to this point,
* accumulating coordinates for a polygon draw operation as
* we go.
*/
lastdir = -1;
ox = x;
oy = y;
ncoords = 0;
do {
/*
* There are eight possible directions we could head in
* from here. We identify them by octant numbers, and
* we also use octant numbers to identify the spaces
* between them:
*
* 6 7 0
* \ 7|0 /
* \ | /
* 6 \|/ 1
* 5-----+-----1
* 5 /|\ 2
* / | \
* / 4|3 \
* 4 3 2
*/
octants[0] = x<w && y>0 ? state->map->map[wh*LE+(y-1)*w+x] : -1;
octants[1] = x<w && y>0 ? state->map->map[wh*BE+(y-1)*w+x] : -1;
octants[2] = x<w && y<h ? state->map->map[wh*TE+y*w+x] : -1;
octants[3] = x<w && y<h ? state->map->map[wh*LE+y*w+x] : -1;
octants[4] = x>0 && y<h ? state->map->map[wh*RE+y*w+(x-1)] : -1;
octants[5] = x>0 && y<h ? state->map->map[wh*TE+y*w+(x-1)] : -1;
octants[6] = x>0 && y>0 ? state->map->map[wh*BE+(y-1)*w+(x-1)] :-1;
octants[7] = x>0 && y>0 ? state->map->map[wh*RE+(y-1)*w+(x-1)] :-1;
d1 = d2 = -1;
for (i = 0; i < 8; i++)
if ((octants[i] == r) ^ (octants[(i+1)%8] == r)) {
assert(d2 == -1);
if (d1 == -1)
d1 = i;
else
d2 = i;
}
assert(d1 != -1 && d2 != -1);
if (d1 == lastdir)
d1 = d2;
/*
* Now we're heading in direction d1. Save the current
* coordinates.
*/
if (ncoords + 2 > coordsize) {
coordsize += 128;
coords = sresize(coords, coordsize, int);
}
coords[ncoords++] = COORD(x);
coords[ncoords++] = COORD(y);
/*
* Compute the new coordinates.
*/
x += (d1 % 4 == 3 ? 0 : d1 < 4 ? +1 : -1);
y += (d1 % 4 == 1 ? 0 : d1 > 1 && d1 < 5 ? +1 : -1);
assert(x >= 0 && x <= w && y >= 0 && y <= h);
lastdir = d1 ^ 4;
} while (x != ox || y != oy);
draw_polygon(dr, coords, ncoords/2,
state->colouring[r] >= 0 ?
c[state->colouring[r]] : -1, ink);
}
sfree(coords);
}
#ifdef COMBINED
#define thegame map
#endif
const struct game thegame = {
"Map", "games.map", "map",
default_params,
game_fetch_preset, NULL,
decode_params,
encode_params,
free_params,
dup_params,
true, game_configure, custom_params,
validate_params,
new_game_desc,
validate_desc,
new_game,
dup_game,
free_game,
true, solve_game,
false, NULL, NULL, /* can_format_as_text_now, text_format */
get_prefs, set_prefs,
new_ui,
free_ui,
NULL, /* encode_ui */
NULL, /* decode_ui */
NULL, /* game_request_keys */
game_changed_state,
current_key_label,
interpret_move,
execute_move,
20, game_compute_size, game_set_size,
game_colours,
game_new_drawstate,
game_free_drawstate,
game_redraw,
game_anim_length,
game_flash_length,
game_get_cursor_location,
game_status,
true, true, game_print_size, game_print,
false, /* wants_statusbar */
false, NULL, /* timing_state */
0, /* flags */
};
#ifdef STANDALONE_SOLVER
int main(int argc, char **argv)
{
game_params *p;
game_state *s;
char *id = NULL, *desc;
const char *err;
bool grade = false;
int ret, diff;
bool really_verbose = false;
struct solver_scratch *sc;
int i;
while (--argc > 0) {
char *p = *++argv;
if (!strcmp(p, "-v")) {
really_verbose = true;
} else if (!strcmp(p, "-g")) {
grade = true;
} else if (*p == '-') {
fprintf(stderr, "%s: unrecognised option `%s'\n", argv[0], p);
return 1;
} else {
id = p;
}
}
if (!id) {
fprintf(stderr, "usage: %s [-g | -v] <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);
sc = new_scratch(s->map->graph, s->map->n, s->map->ngraph);
/*
* When solving an Easy puzzle, we don't want to bother the
* user with Hard-level deductions. For this reason, we grade
* the puzzle internally before doing anything else.
*/
ret = -1; /* placate optimiser */
for (diff = 0; diff < DIFFCOUNT; diff++) {
for (i = 0; i < s->map->n; i++)
if (!s->map->immutable[i])
s->colouring[i] = -1;
ret = map_solver(sc, s->map->graph, s->map->n, s->map->ngraph,
s->colouring, diff);
if (ret < 2)
break;
}
if (diff == DIFFCOUNT) {
if (grade)
printf("Difficulty rating: harder than Hard, or ambiguous\n");
else
printf("Unable to find a unique solution\n");
} else {
if (grade) {
if (ret == 0)
printf("Difficulty rating: impossible (no solution exists)\n");
else if (ret == 1)
printf("Difficulty rating: %s\n", map_diffnames[diff]);
} else {
verbose = really_verbose;
for (i = 0; i < s->map->n; i++)
if (!s->map->immutable[i])
s->colouring[i] = -1;
ret = map_solver(sc, s->map->graph, s->map->n, s->map->ngraph,
s->colouring, diff);
if (ret == 0)
printf("Puzzle is inconsistent\n");
else {
int col = 0;
for (i = 0; i < s->map->n; i++) {
printf("%5d <- %c%c", i, colnames[s->colouring[i]],
(col < 6 && i+1 < s->map->n ? ' ' : '\n'));
if (++col == 7)
col = 0;
}
}
}
}
return 0;
}
#endif
/* vim: set shiftwidth=4 tabstop=8: */