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puzzles/map.c
Ben Harris 789e11f8f8 Remove various unused game functions 
If can_configure is false, then the game's configure() and
custom_params() functions will never be called.  If can_solve is false,
solve() will never be called.  If can_format_as_text_ever is false,
can_format_as_text_now() and text_format() will never be called.  If
can_print is false, print_size() and print() will never be called.  If
is_timed is false, timing_state() will never be called.

In each case, almost all puzzles provided a function nonetheless.  I
think this is because in Puzzles' early history there was no "game"
structure, so the functions had to be present for linking to work.  But
now that everything indirects through the "game" structure, unused
functions can be left unimplemented and the corresponding pointers set
to NULL.

So now where the flags mentioned above are false, the corresponding
functions are omitted and the function pointers in the "game" structures
are NULL.
2023-01-31 23:25:05 +00:00

3394 lines
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/*
* 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>
#include <math.h>
#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
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)
/*
* Ghastly run-time configuration option, just for Gareth (again).
*/
static int flash_type = -1;
static float flash_length;
/*
* 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 / 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;
dsf_init(map+wh, 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')
return "Unexpected character in edge list";
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
return "Too much data in edge list";
if (!state)
dsf_merge(map+wh, 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)
return "Too little data in edge list";
/*
* 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(map+wh, i);
if (map[k] < 0)
map[k] = pos++;
map[i] = map[k];
}
if (pos != n)
return "Edge list defines the wrong number of regions";
*desc = p;
return NULL;
}
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(2*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;
};
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 = false;
ui->cur_moved = false;
ui->cur_lastmove = 0;
return ui;
}
static void free_ui(game_ui *ui)
{
sfree(ui);
}
static char *encode_ui(const game_ui *ui)
{
return NULL;
}
static void decode_ui(game_ui *ui, const char *encoding)
{
}
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 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 UI_UPDATE;
}
if (IS_CURSOR_SELECT(button)) {
if (!ui->cur_visible) {
ui->cur_visible = true;
return 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 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 UI_UPDATE;
}
if ((button == LEFT_DRAG || button == RIGHT_DRAG) &&
ui->drag_colour > -2) {
ui->dragx = x;
ui->dragy = y;
return 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 UI_UPDATE; /* drag into border; do nothing else */
if (state->map->immutable[r])
return UI_UPDATE; /* can't change this region */
if (state->colouring[r] == c && state->pencil[r] == p)
return 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 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,
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 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 (flash_type == 1)
flash = (int)(flashtime * FOUR / flash_length);
else
flash = 1 + (int)(flashtime * THREE / flash_length);
} 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 (flash_type == 1) {
if (tv == flash)
tv = FOUR;
if (bv == flash)
bv = FOUR;
} else if (flash_type == 2) {
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) {
if (flash_type < 0) {
char *env = getenv("MAP_ALTERNATIVE_FLASH");
if (env)
flash_type = atoi(env);
else
flash_type = 0;
flash_length = (flash_type == 1 ? 0.50F : 0.30F);
}
return flash_length;
} 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, 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, &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->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 */
new_ui,
free_ui,
encode_ui,
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: */
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