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puzzles/net.c
Simon Tatham afe80030e4 New puzzle: `Slant', picked from the Japanese-language section of 
nikoli.co.jp (which has quite a few puzzles that they don't seem to
have bothered to translate into English).

Minor structural change: the disjoint set forest code used in the
Net solver has come in handy again, so I've moved it out into its
own module dsf.c.

[originally from svn r6155]
2005-08-02 23:16:46 +00:00

2747 lines
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/*
* net.c: Net game.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <ctype.h>
#include <math.h>
#include "puzzles.h"
#include "tree234.h"
#define MATMUL(xr,yr,m,x,y) do { \
float rx, ry, xx = (x), yy = (y), *mat = (m); \
rx = mat[0] * xx + mat[2] * yy; \
ry = mat[1] * xx + mat[3] * yy; \
(xr) = rx; (yr) = ry; \
} while (0)
/* Direction and other bitfields */
#define R 0x01
#define U 0x02
#define L 0x04
#define D 0x08
#define LOCKED 0x10
#define ACTIVE 0x20
/* Rotations: Anticlockwise, Clockwise, Flip, general rotate */
#define A(x) ( (((x) & 0x07) << 1) | (((x) & 0x08) >> 3) )
#define C(x) ( (((x) & 0x0E) >> 1) | (((x) & 0x01) << 3) )
#define F(x) ( (((x) & 0x0C) >> 2) | (((x) & 0x03) << 2) )
#define ROT(x, n) ( ((n)&3) == 0 ? (x) : \
((n)&3) == 1 ? A(x) : \
((n)&3) == 2 ? F(x) : C(x) )
/* X and Y displacements */
#define X(x) ( (x) == R ? +1 : (x) == L ? -1 : 0 )
#define Y(x) ( (x) == D ? +1 : (x) == U ? -1 : 0 )
/* Bit count */
#define COUNT(x) ( (((x) & 0x08) >> 3) + (((x) & 0x04) >> 2) + \
(((x) & 0x02) >> 1) + ((x) & 0x01) )
#define PREFERRED_TILE_SIZE 32
#define TILE_SIZE (ds->tilesize)
#define TILE_BORDER 1
#define WINDOW_OFFSET 16
#define ROTATE_TIME 0.13F
#define FLASH_FRAME 0.07F
/* Transform physical coords to game coords using game_drawstate ds */
#define GX(x) (((x) + ds->org_x) % ds->width)
#define GY(y) (((y) + ds->org_y) % ds->height)
/* ...and game coords to physical coords */
#define RX(x) (((x) + ds->width - ds->org_x) % ds->width)
#define RY(y) (((y) + ds->height - ds->org_y) % ds->height)
enum {
COL_BACKGROUND,
COL_LOCKED,
COL_BORDER,
COL_WIRE,
COL_ENDPOINT,
COL_POWERED,
COL_BARRIER,
NCOLOURS
};
struct game_params {
int width;
int height;
int wrapping;
int unique;
float barrier_probability;
};
struct game_state {
int width, height, wrapping, completed;
int last_rotate_x, last_rotate_y, last_rotate_dir;
int used_solve, just_used_solve;
unsigned char *tiles;
unsigned char *barriers;
};
#define OFFSETWH(x2,y2,x1,y1,dir,width,height) \
( (x2) = ((x1) + width + X((dir))) % width, \
(y2) = ((y1) + height + Y((dir))) % height)
#define OFFSET(x2,y2,x1,y1,dir,state) \
OFFSETWH(x2,y2,x1,y1,dir,(state)->width,(state)->height)
#define index(state, a, x, y) ( a[(y) * (state)->width + (x)] )
#define tile(state, x, y) index(state, (state)->tiles, x, y)
#define barrier(state, x, y) index(state, (state)->barriers, x, y)
struct xyd {
int x, y, direction;
};
static int xyd_cmp(const void *av, const void *bv) {
const struct xyd *a = (const struct xyd *)av;
const struct xyd *b = (const struct xyd *)bv;
if (a->x < b->x)
return -1;
if (a->x > b->x)
return +1;
if (a->y < b->y)
return -1;
if (a->y > b->y)
return +1;
if (a->direction < b->direction)
return -1;
if (a->direction > b->direction)
return +1;
return 0;
}
static int xyd_cmp_nc(void *av, void *bv) { return xyd_cmp(av, bv); }
static struct xyd *new_xyd(int x, int y, int direction)
{
struct xyd *xyd = snew(struct xyd);
xyd->x = x;
xyd->y = y;
xyd->direction = direction;
return xyd;
}
/* ----------------------------------------------------------------------
* Manage game parameters.
*/
static game_params *default_params(void)
{
game_params *ret = snew(game_params);
ret->width = 5;
ret->height = 5;
ret->wrapping = FALSE;
ret->unique = TRUE;
ret->barrier_probability = 0.0;
return ret;
}
static const struct game_params net_presets[] = {
{5, 5, FALSE, TRUE, 0.0},
{7, 7, FALSE, TRUE, 0.0},
{9, 9, FALSE, TRUE, 0.0},
{11, 11, FALSE, TRUE, 0.0},
{13, 11, FALSE, TRUE, 0.0},
{5, 5, TRUE, TRUE, 0.0},
{7, 7, TRUE, TRUE, 0.0},
{9, 9, TRUE, TRUE, 0.0},
{11, 11, TRUE, TRUE, 0.0},
{13, 11, TRUE, TRUE, 0.0},
};
static int game_fetch_preset(int i, char **name, game_params **params)
{
game_params *ret;
char str[80];
if (i < 0 || i >= lenof(net_presets))
return FALSE;
ret = snew(game_params);
*ret = net_presets[i];
sprintf(str, "%dx%d%s", ret->width, ret->height,
ret->wrapping ? " wrapping" : "");
*name = dupstr(str);
*params = ret;
return TRUE;
}
static void free_params(game_params *params)
{
sfree(params);
}
static game_params *dup_params(game_params *params)
{
game_params *ret = snew(game_params);
*ret = *params; /* structure copy */
return ret;
}
static void decode_params(game_params *ret, char const *string)
{
char const *p = string;
ret->width = atoi(p);
while (*p && isdigit((unsigned char)*p)) p++;
if (*p == 'x') {
p++;
ret->height = atoi(p);
while (*p && isdigit((unsigned char)*p)) p++;
} else {
ret->height = ret->width;
}
while (*p) {
if (*p == 'w') {
p++;
ret->wrapping = TRUE;
} else if (*p == 'b') {
p++;
ret->barrier_probability = atof(p);
while (*p && (*p == '.' || isdigit((unsigned char)*p))) p++;
} else if (*p == 'a') {
p++;
ret->unique = FALSE;
} else
p++; /* skip any other gunk */
}
}
static char *encode_params(game_params *params, int full)
{
char ret[400];
int len;
len = sprintf(ret, "%dx%d", params->width, params->height);
if (params->wrapping)
ret[len++] = 'w';
if (full && params->barrier_probability)
len += sprintf(ret+len, "b%g", params->barrier_probability);
if (full && !params->unique)
ret[len++] = 'a';
assert(len < lenof(ret));
ret[len] = '\0';
return dupstr(ret);
}
static config_item *game_configure(game_params *params)
{
config_item *ret;
char buf[80];
ret = snewn(6, config_item);
ret[0].name = "Width";
ret[0].type = C_STRING;
sprintf(buf, "%d", params->width);
ret[0].sval = dupstr(buf);
ret[0].ival = 0;
ret[1].name = "Height";
ret[1].type = C_STRING;
sprintf(buf, "%d", params->height);
ret[1].sval = dupstr(buf);
ret[1].ival = 0;
ret[2].name = "Walls wrap around";
ret[2].type = C_BOOLEAN;
ret[2].sval = NULL;
ret[2].ival = params->wrapping;
ret[3].name = "Barrier probability";
ret[3].type = C_STRING;
sprintf(buf, "%g", params->barrier_probability);
ret[3].sval = dupstr(buf);
ret[3].ival = 0;
ret[4].name = "Ensure unique solution";
ret[4].type = C_BOOLEAN;
ret[4].sval = NULL;
ret[4].ival = params->unique;
ret[5].name = NULL;
ret[5].type = C_END;
ret[5].sval = NULL;
ret[5].ival = 0;
return ret;
}
static game_params *custom_params(config_item *cfg)
{
game_params *ret = snew(game_params);
ret->width = atoi(cfg[0].sval);
ret->height = atoi(cfg[1].sval);
ret->wrapping = cfg[2].ival;
ret->barrier_probability = (float)atof(cfg[3].sval);
ret->unique = cfg[4].ival;
return ret;
}
static char *validate_params(game_params *params, int full)
{
if (params->width <= 0 || params->height <= 0)
return "Width and height must both be greater than zero";
if (params->width <= 1 && params->height <= 1)
return "At least one of width and height must be greater than one";
if (params->barrier_probability < 0)
return "Barrier probability may not be negative";
if (params->barrier_probability > 1)
return "Barrier probability may not be greater than 1";
/*
* Specifying either grid dimension as 2 in a wrapping puzzle
* makes it actually impossible to ensure a unique puzzle
* solution.
*
* Proof:
*
* Without loss of generality, let us assume the puzzle _width_
* is 2, so we can conveniently discuss rows without having to
* say `rows/columns' all the time. (The height may be 2 as
* well, but that doesn't matter.)
*
* In each row, there are two edges between tiles: the inner
* edge (running down the centre of the grid) and the outer
* edge (the identified left and right edges of the grid).
*
* Lemma: In any valid 2xn puzzle there must be at least one
* row in which _exactly one_ of the inner edge and outer edge
* is connected.
*
* Proof: No row can have _both_ inner and outer edges
* connected, because this would yield a loop. So the only
* other way to falsify the lemma is for every row to have
* _neither_ the inner nor outer edge connected. But this
* means there is no connection at all between the left and
* right columns of the puzzle, so there are two disjoint
* subgraphs, which is also disallowed. []
*
* Given such a row, it is always possible to make the
* disconnected edge connected and the connected edge
* disconnected without changing the state of any other edge.
* (This is easily seen by case analysis on the various tiles:
* left-pointing and right-pointing endpoints can be exchanged,
* likewise T-pieces, and a corner piece can select its
* horizontal connectivity independently of its vertical.) This
* yields a distinct valid solution.
*
* Thus, for _every_ row in which exactly one of the inner and
* outer edge is connected, there are two valid states for that
* row, and hence the total number of solutions of the puzzle
* is at least 2^(number of such rows), and in particular is at
* least 2 since there must be at least one such row. []
*/
if (full && params->unique && params->wrapping &&
(params->width == 2 || params->height == 2))
return "No wrapping puzzle with a width or height of 2 can have"
" a unique solution";
return NULL;
}
/* ----------------------------------------------------------------------
* Solver used to assure solution uniqueness during generation.
*/
/*
* Test cases I used while debugging all this were
*
* ./net --generate 1 13x11w#12300
* which expands under the non-unique grid generation rules to
* 13x11w:5eaade1bd222664436d5e2965c12656b1129dd825219e3274d558d5eb2dab5da18898e571d5a2987be79746bd95726c597447d6da96188c513add829da7681da954db113d3cd244
* and has two ambiguous areas.
*
* An even better one is
* 13x11w#507896411361192
* which expands to
* 13x11w:b7125b1aec598eb31bd58d82572bc11494e5dee4e8db2bdd29b88d41a16bdd996d2996ddec8c83741a1e8674e78328ba71737b8894a9271b1cd1399453d1952e43951d9b712822e
* and has an ambiguous area _and_ a situation where loop avoidance
* is a necessary deductive technique.
*
* Then there's
* 48x25w#820543338195187
* becoming
* 48x25w:255989d14cdd185deaa753a93821a12edc1ab97943ac127e2685d7b8b3c48861b2192416139212b316eddd35de43714ebc7628d753db32e596284d9ec52c5a7dc1b4c811a655117d16dc28921b2b4161352cab1d89d18bc836b8b891d55ea4622a1251861b5bc9a8aa3e5bcd745c95229ca6c3b5e21d5832d397e917325793d7eb442dc351b2db2a52ba8e1651642275842d8871d5534aabc6d5b741aaa2d48ed2a7dbbb3151ddb49d5b9a7ed1ab98ee75d613d656dbba347bc514c84556b43a9bc65a3256ead792488b862a9d2a8a39b4255a4949ed7dbd79443292521265896b4399c95ede89d7c8c797a6a57791a849adea489359a158aa12e5dacce862b8333b7ebea7d344d1a3c53198864b73a9dedde7b663abb1b539e1e8853b1b7edb14a2a17ebaae4dbe63598a2e7e9a2dbdad415bc1d8cb88cbab5a8c82925732cd282e641ea3bd7d2c6e776de9117a26be86deb7c82c89524b122cb9397cd1acd2284e744ea62b9279bae85479ababe315c3ac29c431333395b24e6a1e3c43a2da42d4dce84aadd5b154aea555eaddcbd6e527d228c19388d9b424d94214555a7edbdeebe569d4a56dc51a86bd9963e377bb74752bd5eaa5761ba545e297b62a1bda46ab4aee423ad6c661311783cc18786d4289236563cb4a75ec67d481c14814994464cd1b87396dee63e5ab6e952cc584baa1d4c47cb557ec84dbb63d487c8728118673a166846dd3a4ebc23d6cb9c5827d96b4556e91899db32b517eda815ae271a8911bd745447121dc8d321557bc2a435ebec1bbac35b1a291669451174e6aa2218a4a9c5a6ca31ebc45d84e3a82c121e9ced7d55e9a
* which has a spot (far right) where slightly more complex loop
* avoidance is required.
*/
struct todo {
unsigned char *marked;
int *buffer;
int buflen;
int head, tail;
};
static struct todo *todo_new(int maxsize)
{
struct todo *todo = snew(struct todo);
todo->marked = snewn(maxsize, unsigned char);
memset(todo->marked, 0, maxsize);
todo->buflen = maxsize + 1;
todo->buffer = snewn(todo->buflen, int);
todo->head = todo->tail = 0;
return todo;
}
static void todo_free(struct todo *todo)
{
sfree(todo->marked);
sfree(todo->buffer);
sfree(todo);
}
static void todo_add(struct todo *todo, int index)
{
if (todo->marked[index])
return; /* already on the list */
todo->marked[index] = TRUE;
todo->buffer[todo->tail++] = index;
if (todo->tail == todo->buflen)
todo->tail = 0;
}
static int todo_get(struct todo *todo) {
int ret;
if (todo->head == todo->tail)
return -1; /* list is empty */
ret = todo->buffer[todo->head++];
if (todo->head == todo->buflen)
todo->head = 0;
todo->marked[ret] = FALSE;
return ret;
}
static int net_solver(int w, int h, unsigned char *tiles,
unsigned char *barriers, int wrapping)
{
unsigned char *tilestate;
unsigned char *edgestate;
int *deadends;
int *equivalence;
struct todo *todo;
int i, j, x, y;
int area;
int done_something;
/*
* Set up the solver's data structures.
*/
/*
* tilestate stores the possible orientations of each tile.
* There are up to four of these, so we'll index the array in
* fours. tilestate[(y * w + x) * 4] and its three successive
* members give the possible orientations, clearing to 255 from
* the end as things are ruled out.
*
* In this loop we also count up the area of the grid (which is
* not _necessarily_ equal to w*h, because there might be one
* or more blank squares present. This will never happen in a
* grid generated _by_ this program, but it's worth keeping the
* solver as general as possible.)
*/
tilestate = snewn(w * h * 4, unsigned char);
area = 0;
for (i = 0; i < w*h; i++) {
tilestate[i * 4] = tiles[i] & 0xF;
for (j = 1; j < 4; j++) {
if (tilestate[i * 4 + j - 1] == 255 ||
A(tilestate[i * 4 + j - 1]) == tilestate[i * 4])
tilestate[i * 4 + j] = 255;
else
tilestate[i * 4 + j] = A(tilestate[i * 4 + j - 1]);
}
if (tiles[i] != 0)
area++;
}
/*
* edgestate stores the known state of each edge. It is 0 for
* unknown, 1 for open (connected) and 2 for closed (not
* connected).
*
* In principle we need only worry about each edge once each,
* but in fact it's easier to track each edge twice so that we
* can reference it from either side conveniently. Also I'm
* going to allocate _five_ bytes per tile, rather than the
* obvious four, so that I can index edgestate[(y*w+x) * 5 + d]
* where d is 1,2,4,8 and they never overlap.
*/
edgestate = snewn((w * h - 1) * 5 + 9, unsigned char);
memset(edgestate, 0, (w * h - 1) * 5 + 9);
/*
* deadends tracks which edges have dead ends on them. It is
* indexed by tile and direction: deadends[(y*w+x) * 5 + d]
* tells you whether heading out of tile (x,y) in direction d
* can reach a limited amount of the grid. Values are area+1
* (no dead end known) or less than that (can reach _at most_
* this many other tiles by heading this way out of this tile).
*/
deadends = snewn((w * h - 1) * 5 + 9, int);
for (i = 0; i < (w * h - 1) * 5 + 9; i++)
deadends[i] = area+1;
/*
* equivalence tracks which sets of tiles are known to be
* connected to one another, so we can avoid creating loops by
* linking together tiles which are already linked through
* another route.
*
* This is a disjoint set forest structure: equivalence[i]
* contains the index of another member of the equivalence
* class containing i, or contains i itself for precisely one
* member in each such class. To find a representative member
* of the equivalence class containing i, you keep replacing i
* with equivalence[i] until it stops changing; then you go
* _back_ along the same path and point everything on it
* directly at the representative member so as to speed up
* future searches. Then you test equivalence between tiles by
* finding the representative of each tile and seeing if
* they're the same; and you create new equivalence (merge
* classes) by finding the representative of each tile and
* setting equivalence[one]=the_other.
*/
equivalence = snewn(w * h, int);
for (i = 0; i < w*h; i++)
equivalence[i] = i; /* initially all distinct */
/*
* On a non-wrapping grid, we instantly know that all the edges
* round the edge are closed.
*/
if (!wrapping) {
for (i = 0; i < w; i++) {
edgestate[i * 5 + 2] = edgestate[((h-1) * w + i) * 5 + 8] = 2;
}
for (i = 0; i < h; i++) {
edgestate[(i * w + w-1) * 5 + 1] = edgestate[(i * w) * 5 + 4] = 2;
}
}
/*
* If we have barriers available, we can mark those edges as
* closed too.
*/
if (barriers) {
for (y = 0; y < h; y++) for (x = 0; x < w; x++) {
int d;
for (d = 1; d <= 8; d += d) {
if (barriers[y*w+x] & d) {
int x2, y2;
/*
* In principle the barrier list should already
* contain each barrier from each side, but
* let's not take chances with our internal
* consistency.
*/
OFFSETWH(x2, y2, x, y, d, w, h);
edgestate[(y*w+x) * 5 + d] = 2;
edgestate[(y2*w+x2) * 5 + F(d)] = 2;
}
}
}
}
/*
* Since most deductions made by this solver are local (the
* exception is loop avoidance, where joining two tiles
* together on one side of the grid can theoretically permit a
* fresh deduction on the other), we can address the scaling
* problem inherent in iterating repeatedly over the entire
* grid by instead working with a to-do list.
*/
todo = todo_new(w * h);
/*
* Main deductive loop.
*/
done_something = TRUE; /* prevent instant termination! */
while (1) {
int index;
/*
* Take a tile index off the todo list and process it.
*/
index = todo_get(todo);
if (index == -1) {
/*
* If we have run out of immediate things to do, we
* have no choice but to scan the whole grid for
* longer-range things we've missed. Hence, I now add
* every square on the grid back on to the to-do list.
* I also set `done_something' to FALSE at this point;
* if we later come back here and find it still FALSE,
* we will know we've scanned the entire grid without
* finding anything new to do, and we can terminate.
*/
if (!done_something)
break;
for (i = 0; i < w*h; i++)
todo_add(todo, i);
done_something = FALSE;
index = todo_get(todo);
}
y = index / w;
x = index % w;
{
int d, ourclass = dsf_canonify(equivalence, y*w+x);
int deadendmax[9];
deadendmax[1] = deadendmax[2] = deadendmax[4] = deadendmax[8] = 0;
for (i = j = 0; i < 4 && tilestate[(y*w+x) * 4 + i] != 255; i++) {
int valid;
int nnondeadends, nondeadends[4], deadendtotal;
int nequiv, equiv[5];
int val = tilestate[(y*w+x) * 4 + i];
valid = TRUE;
nnondeadends = deadendtotal = 0;
equiv[0] = ourclass;
nequiv = 1;
for (d = 1; d <= 8; d += d) {
/*
* Immediately rule out this orientation if it
* conflicts with any known edge.
*/
if ((edgestate[(y*w+x) * 5 + d] == 1 && !(val & d)) ||
(edgestate[(y*w+x) * 5 + d] == 2 && (val & d)))
valid = FALSE;
if (val & d) {
/*
* Count up the dead-end statistics.
*/
if (deadends[(y*w+x) * 5 + d] <= area) {
deadendtotal += deadends[(y*w+x) * 5 + d];
} else {
nondeadends[nnondeadends++] = d;
}
/*
* Ensure we aren't linking to any tiles,
* through edges not already known to be
* open, which create a loop.
*/
if (edgestate[(y*w+x) * 5 + d] == 0) {
int c, k, x2, y2;
OFFSETWH(x2, y2, x, y, d, w, h);
c = dsf_canonify(equivalence, y2*w+x2);
for (k = 0; k < nequiv; k++)
if (c == equiv[k])
break;
if (k == nequiv)
equiv[nequiv++] = c;
else
valid = FALSE;
}
}
}
if (nnondeadends == 0) {
/*
* If this orientation links together dead-ends
* with a total area of less than the entire
* grid, it is invalid.
*
* (We add 1 to deadendtotal because of the
* tile itself, of course; one tile linking
* dead ends of size 2 and 3 forms a subnetwork
* with a total area of 6, not 5.)
*/
if (deadendtotal > 0 && deadendtotal+1 < area)
valid = FALSE;
} else if (nnondeadends == 1) {
/*
* If this orientation links together one or
* more dead-ends with precisely one
* non-dead-end, then we may have to mark that
* non-dead-end as a dead end going the other
* way. However, it depends on whether all
* other orientations share the same property.
*/
deadendtotal++;
if (deadendmax[nondeadends[0]] < deadendtotal)
deadendmax[nondeadends[0]] = deadendtotal;
} else {
/*
* If this orientation links together two or
* more non-dead-ends, then we can rule out the
* possibility of putting in new dead-end
* markings in those directions.
*/
int k;
for (k = 0; k < nnondeadends; k++)
deadendmax[nondeadends[k]] = area+1;
}
if (valid)
tilestate[(y*w+x) * 4 + j++] = val;
#ifdef SOLVER_DIAGNOSTICS
else
printf("ruling out orientation %x at %d,%d\n", val, x, y);
#endif
}
assert(j > 0); /* we can't lose _all_ possibilities! */
if (j < i) {
done_something = TRUE;
/*
* We have ruled out at least one tile orientation.
* Make sure the rest are blanked.
*/
while (j < 4)
tilestate[(y*w+x) * 4 + j++] = 255;
}
/*
* Now go through the tile orientations again and see
* if we've deduced anything new about any edges.
*/
{
int a, o;
a = 0xF; o = 0;
for (i = 0; i < 4 && tilestate[(y*w+x) * 4 + i] != 255; i++) {
a &= tilestate[(y*w+x) * 4 + i];
o |= tilestate[(y*w+x) * 4 + i];
}
for (d = 1; d <= 8; d += d)
if (edgestate[(y*w+x) * 5 + d] == 0) {
int x2, y2, d2;
OFFSETWH(x2, y2, x, y, d, w, h);
d2 = F(d);
if (a & d) {
/* This edge is open in all orientations. */
#ifdef SOLVER_DIAGNOSTICS
printf("marking edge %d,%d:%d open\n", x, y, d);
#endif
edgestate[(y*w+x) * 5 + d] = 1;
edgestate[(y2*w+x2) * 5 + d2] = 1;
dsf_merge(equivalence, y*w+x, y2*w+x2);
done_something = TRUE;
todo_add(todo, y2*w+x2);
} else if (!(o & d)) {
/* This edge is closed in all orientations. */
#ifdef SOLVER_DIAGNOSTICS
printf("marking edge %d,%d:%d closed\n", x, y, d);
#endif
edgestate[(y*w+x) * 5 + d] = 2;
edgestate[(y2*w+x2) * 5 + d2] = 2;
done_something = TRUE;
todo_add(todo, y2*w+x2);
}
}
}
/*
* Now check the dead-end markers and see if any of
* them has lowered from the real ones.
*/
for (d = 1; d <= 8; d += d) {
int x2, y2, d2;
OFFSETWH(x2, y2, x, y, d, w, h);
d2 = F(d);
if (deadendmax[d] > 0 &&
deadends[(y2*w+x2) * 5 + d2] > deadendmax[d]) {
#ifdef SOLVER_DIAGNOSTICS
printf("setting dead end value %d,%d:%d to %d\n",
x2, y2, d2, deadendmax[d]);
#endif
deadends[(y2*w+x2) * 5 + d2] = deadendmax[d];
done_something = TRUE;
todo_add(todo, y2*w+x2);
}
}
}
}
/*
* Mark all completely determined tiles as locked.
*/
j = TRUE;
for (i = 0; i < w*h; i++) {
if (tilestate[i * 4 + 1] == 255) {
assert(tilestate[i * 4 + 0] != 255);
tiles[i] = tilestate[i * 4] | LOCKED;
} else {
tiles[i] &= ~LOCKED;
j = FALSE;
}
}
/*
* Free up working space.
*/
todo_free(todo);
sfree(tilestate);
sfree(edgestate);
sfree(deadends);
sfree(equivalence);
return j;
}
/* ----------------------------------------------------------------------
* Randomly select a new game description.
*/
/*
* Function to randomly perturb an ambiguous section in a grid, to
* attempt to ensure unique solvability.
*/
static void perturb(int w, int h, unsigned char *tiles, int wrapping,
random_state *rs, int startx, int starty, int startd)
{
struct xyd *perimeter, *perim2, *loop[2], looppos[2];
int nperim, perimsize, nloop[2], loopsize[2];
int x, y, d, i;
/*
* We know that the tile at (startx,starty) is part of an
* ambiguous section, and we also know that its neighbour in
* direction startd is fully specified. We begin by tracing all
* the way round the ambiguous area.
*/
nperim = perimsize = 0;
perimeter = NULL;
x = startx;
y = starty;
d = startd;
#ifdef PERTURB_DIAGNOSTICS
printf("perturb %d,%d:%d\n", x, y, d);
#endif
do {
int x2, y2, d2;
if (nperim >= perimsize) {
perimsize = perimsize * 3 / 2 + 32;
perimeter = sresize(perimeter, perimsize, struct xyd);
}
perimeter[nperim].x = x;
perimeter[nperim].y = y;
perimeter[nperim].direction = d;
nperim++;
#ifdef PERTURB_DIAGNOSTICS
printf("perimeter: %d,%d:%d\n", x, y, d);
#endif
/*
* First, see if we can simply turn left from where we are
* and find another locked square.
*/
d2 = A(d);
OFFSETWH(x2, y2, x, y, d2, w, h);
if ((!wrapping && (abs(x2-x) > 1 || abs(y2-y) > 1)) ||
(tiles[y2*w+x2] & LOCKED)) {
d = d2;
} else {
/*
* Failing that, step left into the new square and look
* in front of us.
*/
x = x2;
y = y2;
OFFSETWH(x2, y2, x, y, d, w, h);
if ((wrapping || (abs(x2-x) <= 1 && abs(y2-y) <= 1)) &&
!(tiles[y2*w+x2] & LOCKED)) {
/*
* And failing _that_, we're going to have to step
* forward into _that_ square and look right at the
* same locked square as we started with.
*/
x = x2;
y = y2;
d = C(d);
}
}
} while (x != startx || y != starty || d != startd);
/*
* Our technique for perturbing this ambiguous area is to
* search round its edge for a join we can make: that is, an
* edge on the perimeter which is (a) not currently connected,
* and (b) connecting it would not yield a full cross on either
* side. Then we make that join, search round the network to
* find the loop thus constructed, and sever the loop at a
* randomly selected other point.
*/
perim2 = snewn(nperim, struct xyd);
memcpy(perim2, perimeter, nperim * sizeof(struct xyd));
/* Shuffle the perimeter, so as to search it without directional bias. */
for (i = nperim; --i ;) {
int j = random_upto(rs, i+1);
struct xyd t;
t = perim2[j];
perim2[j] = perim2[i];
perim2[i] = t;
}
for (i = 0; i < nperim; i++) {
int x2, y2;
x = perim2[i].x;
y = perim2[i].y;
d = perim2[i].direction;
OFFSETWH(x2, y2, x, y, d, w, h);
if (!wrapping && (abs(x2-x) > 1 || abs(y2-y) > 1))
continue; /* can't link across non-wrapping border */
if (tiles[y*w+x] & d)
continue; /* already linked in this direction! */
if (((tiles[y*w+x] | d) & 15) == 15)
continue; /* can't turn this tile into a cross */
if (((tiles[y2*w+x2] | F(d)) & 15) == 15)
continue; /* can't turn other tile into a cross */
/*
* We've found the point at which we're going to make a new
* link.
*/
#ifdef PERTURB_DIAGNOSTICS
printf("linking %d,%d:%d\n", x, y, d);
#endif
tiles[y*w+x] |= d;
tiles[y2*w+x2] |= F(d);
break;
}
sfree(perim2);
if (i == nperim)
return; /* nothing we can do! */
/*
* Now we've constructed a new link, we need to find the entire
* loop of which it is a part.
*
* In principle, this involves doing a complete search round
* the network. However, I anticipate that in the vast majority
* of cases the loop will be quite small, so what I'm going to
* do is make _two_ searches round the network in parallel, one
* keeping its metaphorical hand on the left-hand wall while
* the other keeps its hand on the right. As soon as one of
* them gets back to its starting point, I abandon the other.
*/
for (i = 0; i < 2; i++) {
loopsize[i] = nloop[i] = 0;
loop[i] = NULL;
looppos[i].x = x;
looppos[i].y = y;
looppos[i].direction = d;
}
while (1) {
for (i = 0; i < 2; i++) {
int x2, y2, j;
x = looppos[i].x;
y = looppos[i].y;
d = looppos[i].direction;
OFFSETWH(x2, y2, x, y, d, w, h);
/*
* Add this path segment to the loop, unless it exactly
* reverses the previous one on the loop in which case
* we take it away again.
*/
#ifdef PERTURB_DIAGNOSTICS
printf("looppos[%d] = %d,%d:%d\n", i, x, y, d);
#endif
if (nloop[i] > 0 &&
loop[i][nloop[i]-1].x == x2 &&
loop[i][nloop[i]-1].y == y2 &&
loop[i][nloop[i]-1].direction == F(d)) {
#ifdef PERTURB_DIAGNOSTICS
printf("removing path segment %d,%d:%d from loop[%d]\n",
x2, y2, F(d), i);
#endif
nloop[i]--;
} else {
if (nloop[i] >= loopsize[i]) {
loopsize[i] = loopsize[i] * 3 / 2 + 32;
loop[i] = sresize(loop[i], loopsize[i], struct xyd);
}
#ifdef PERTURB_DIAGNOSTICS
printf("adding path segment %d,%d:%d to loop[%d]\n",
x, y, d, i);
#endif
loop[i][nloop[i]++] = looppos[i];
}
#ifdef PERTURB_DIAGNOSTICS
printf("tile at new location is %x\n", tiles[y2*w+x2] & 0xF);
#endif
d = F(d);
for (j = 0; j < 4; j++) {
if (i == 0)
d = A(d);
else
d = C(d);
#ifdef PERTURB_DIAGNOSTICS
printf("trying dir %d\n", d);
#endif
if (tiles[y2*w+x2] & d) {
looppos[i].x = x2;
looppos[i].y = y2;
looppos[i].direction = d;
break;
}
}
assert(j < 4);
assert(nloop[i] > 0);
if (looppos[i].x == loop[i][0].x &&
looppos[i].y == loop[i][0].y &&
looppos[i].direction == loop[i][0].direction) {
#ifdef PERTURB_DIAGNOSTICS
printf("loop %d finished tracking\n", i);
#endif
/*
* Having found our loop, we now sever it at a
* randomly chosen point - absolutely any will do -
* which is not the one we joined it at to begin
* with. Conveniently, the one we joined it at is
* loop[i][0], so we just avoid that one.
*/
j = random_upto(rs, nloop[i]-1) + 1;
x = loop[i][j].x;
y = loop[i][j].y;
d = loop[i][j].direction;
OFFSETWH(x2, y2, x, y, d, w, h);
tiles[y*w+x] &= ~d;
tiles[y2*w+x2] &= ~F(d);
break;
}
}
if (i < 2)
break;
}
sfree(loop[0]);
sfree(loop[1]);
/*
* Finally, we must mark the entire disputed section as locked,
* to prevent the perturb function being called on it multiple
* times.
*
* To do this, we _sort_ the perimeter of the area. The
* existing xyd_cmp function will arrange things into columns
* for us, in such a way that each column has the edges in
* vertical order. Then we can work down each column and fill
* in all the squares between an up edge and a down edge.
*/
qsort(perimeter, nperim, sizeof(struct xyd), xyd_cmp);
x = y = -1;
for (i = 0; i <= nperim; i++) {
if (i == nperim || perimeter[i].x > x) {
/*
* Fill in everything from the last Up edge to the
* bottom of the grid, if necessary.
*/
if (x != -1) {
while (y < h) {
#ifdef PERTURB_DIAGNOSTICS
printf("resolved: locking tile %d,%d\n", x, y);
#endif
tiles[y * w + x] |= LOCKED;
y++;
}
x = y = -1;
}
if (i == nperim)
break;
x = perimeter[i].x;
y = 0;
}
if (perimeter[i].direction == U) {
x = perimeter[i].x;
y = perimeter[i].y;
} else if (perimeter[i].direction == D) {
/*
* Fill in everything from the last Up edge to here.
*/
assert(x == perimeter[i].x && y <= perimeter[i].y);
while (y <= perimeter[i].y) {
#ifdef PERTURB_DIAGNOSTICS
printf("resolved: locking tile %d,%d\n", x, y);
#endif
tiles[y * w + x] |= LOCKED;
y++;
}
x = y = -1;
}
}
sfree(perimeter);
}
static char *new_game_desc(game_params *params, random_state *rs,
char **aux, int interactive)
{
tree234 *possibilities, *barriertree;
int w, h, x, y, cx, cy, nbarriers;
unsigned char *tiles, *barriers;
char *desc, *p;
w = params->width;
h = params->height;
cx = w / 2;
cy = h / 2;
tiles = snewn(w * h, unsigned char);
barriers = snewn(w * h, unsigned char);
begin_generation:
memset(tiles, 0, w * h);
memset(barriers, 0, w * h);
/*
* Construct the unshuffled grid.
*
* To do this, we simply start at the centre point, repeatedly
* choose a random possibility out of the available ways to
* extend a used square into an unused one, and do it. After
* extending the third line out of a square, we remove the
* fourth from the possibilities list to avoid any full-cross
* squares (which would make the game too easy because they
* only have one orientation).
*
* The slightly worrying thing is the avoidance of full-cross
* squares. Can this cause our unsophisticated construction
* algorithm to paint itself into a corner, by getting into a
* situation where there are some unreached squares and the
* only way to reach any of them is to extend a T-piece into a
* full cross?
*
* Answer: no it can't, and here's a proof.
*
* Any contiguous group of such unreachable squares must be
* surrounded on _all_ sides by T-pieces pointing away from the
* group. (If not, then there is a square which can be extended
* into one of the `unreachable' ones, and so it wasn't
* unreachable after all.) In particular, this implies that
* each contiguous group of unreachable squares must be
* rectangular in shape (any deviation from that yields a
* non-T-piece next to an `unreachable' square).
*
* So we have a rectangle of unreachable squares, with T-pieces
* forming a solid border around the rectangle. The corners of
* that border must be connected (since every tile connects all
* the lines arriving in it), and therefore the border must
* form a closed loop around the rectangle.
*
* But this can't have happened in the first place, since we
* _know_ we've avoided creating closed loops! Hence, no such
* situation can ever arise, and the naive grid construction
* algorithm will guaranteeably result in a complete grid
* containing no unreached squares, no full crosses _and_ no
* closed loops. []
*/
possibilities = newtree234(xyd_cmp_nc);
if (cx+1 < w)
add234(possibilities, new_xyd(cx, cy, R));
if (cy-1 >= 0)
add234(possibilities, new_xyd(cx, cy, U));
if (cx-1 >= 0)
add234(possibilities, new_xyd(cx, cy, L));
if (cy+1 < h)
add234(possibilities, new_xyd(cx, cy, D));
while (count234(possibilities) > 0) {
int i;
struct xyd *xyd;
int x1, y1, d1, x2, y2, d2, d;
/*
* Extract a randomly chosen possibility from the list.
*/
i = random_upto(rs, count234(possibilities));
xyd = delpos234(possibilities, i);
x1 = xyd->x;
y1 = xyd->y;
d1 = xyd->direction;
sfree(xyd);
OFFSET(x2, y2, x1, y1, d1, params);
d2 = F(d1);
#ifdef GENERATION_DIAGNOSTICS
printf("picked (%d,%d,%c) <-> (%d,%d,%c)\n",
x1, y1, "0RU3L567D9abcdef"[d1], x2, y2, "0RU3L567D9abcdef"[d2]);
#endif
/*
* Make the connection. (We should be moving to an as yet
* unused tile.)
*/
index(params, tiles, x1, y1) |= d1;
assert(index(params, tiles, x2, y2) == 0);
index(params, tiles, x2, y2) |= d2;
/*
* If we have created a T-piece, remove its last
* possibility.
*/
if (COUNT(index(params, tiles, x1, y1)) == 3) {
struct xyd xyd1, *xydp;
xyd1.x = x1;
xyd1.y = y1;
xyd1.direction = 0x0F ^ index(params, tiles, x1, y1);
xydp = find234(possibilities, &xyd1, NULL);
if (xydp) {
#ifdef GENERATION_DIAGNOSTICS
printf("T-piece; removing (%d,%d,%c)\n",
xydp->x, xydp->y, "0RU3L567D9abcdef"[xydp->direction]);
#endif
del234(possibilities, xydp);
sfree(xydp);
}
}
/*
* Remove all other possibilities that were pointing at the
* tile we've just moved into.
*/
for (d = 1; d < 0x10; d <<= 1) {
int x3, y3, d3;
struct xyd xyd1, *xydp;
OFFSET(x3, y3, x2, y2, d, params);
d3 = F(d);
xyd1.x = x3;
xyd1.y = y3;
xyd1.direction = d3;
xydp = find234(possibilities, &xyd1, NULL);
if (xydp) {
#ifdef GENERATION_DIAGNOSTICS
printf("Loop avoidance; removing (%d,%d,%c)\n",
xydp->x, xydp->y, "0RU3L567D9abcdef"[xydp->direction]);
#endif
del234(possibilities, xydp);
sfree(xydp);
}
}
/*
* Add new possibilities to the list for moving _out_ of
* the tile we have just moved into.
*/
for (d = 1; d < 0x10; d <<= 1) {
int x3, y3;
if (d == d2)
continue; /* we've got this one already */
if (!params->wrapping) {
if (d == U && y2 == 0)
continue;
if (d == D && y2 == h-1)
continue;
if (d == L && x2 == 0)
continue;
if (d == R && x2 == w-1)
continue;
}
OFFSET(x3, y3, x2, y2, d, params);
if (index(params, tiles, x3, y3))
continue; /* this would create a loop */
#ifdef GENERATION_DIAGNOSTICS
printf("New frontier; adding (%d,%d,%c)\n",
x2, y2, "0RU3L567D9abcdef"[d]);
#endif
add234(possibilities, new_xyd(x2, y2, d));
}
}
/* Having done that, we should have no possibilities remaining. */
assert(count234(possibilities) == 0);
freetree234(possibilities);
if (params->unique) {
int prevn = -1;
/*
* Run the solver to check unique solubility.
*/
while (!net_solver(w, h, tiles, NULL, params->wrapping)) {
int n = 0;
/*
* We expect (in most cases) that most of the grid will
* be uniquely specified already, and the remaining
* ambiguous sections will be small and separate. So
* our strategy is to find each individual such
* section, and perform a perturbation on the network
* in that area.
*/
for (y = 0; y < h; y++) for (x = 0; x < w; x++) {
if (x+1 < w && ((tiles[y*w+x] ^ tiles[y*w+x+1]) & LOCKED)) {
n++;
if (tiles[y*w+x] & LOCKED)
perturb(w, h, tiles, params->wrapping, rs, x+1, y, L);
else
perturb(w, h, tiles, params->wrapping, rs, x, y, R);
}
if (y+1 < h && ((tiles[y*w+x] ^ tiles[(y+1)*w+x]) & LOCKED)) {
n++;
if (tiles[y*w+x] & LOCKED)
perturb(w, h, tiles, params->wrapping, rs, x, y+1, U);
else
perturb(w, h, tiles, params->wrapping, rs, x, y, D);
}
}
/*
* Now n counts the number of ambiguous sections we
* have fiddled with. If we haven't managed to decrease
* it from the last time we ran the solver, give up and
* regenerate the entire grid.
*/
if (prevn != -1 && prevn <= n)
goto begin_generation; /* (sorry) */
prevn = n;
}
/*
* The solver will have left a lot of LOCKED bits lying
* around in the tiles array. Remove them.
*/
for (x = 0; x < w*h; x++)
tiles[x] &= ~LOCKED;
}
/*
* Now compute a list of the possible barrier locations.
*/
barriertree = newtree234(xyd_cmp_nc);
for (y = 0; y < h; y++) {
for (x = 0; x < w; x++) {
if (!(index(params, tiles, x, y) & R) &&
(params->wrapping || x < w-1))
add234(barriertree, new_xyd(x, y, R));
if (!(index(params, tiles, x, y) & D) &&
(params->wrapping || y < h-1))
add234(barriertree, new_xyd(x, y, D));
}
}
/*
* Save the unshuffled grid in aux.
*/
{
char *solution;
int i;
solution = snewn(w * h + 1, char);
for (i = 0; i < w * h; i++)
solution[i] = "0123456789abcdef"[tiles[i] & 0xF];
solution[w*h] = '\0';
*aux = solution;
}
/*
* Now shuffle the grid.
*/
for (y = 0; y < h; y++) {
for (x = 0; x < w; x++) {
int orig = index(params, tiles, x, y);
int rot = random_upto(rs, 4);
index(params, tiles, x, y) = ROT(orig, rot);
}
}
/*
* And now choose barrier locations. (We carefully do this
* _after_ shuffling, so that changing the barrier rate in the
* params while keeping the random seed the same will give the
* same shuffled grid and _only_ change the barrier locations.
* Also the way we choose barrier locations, by repeatedly
* choosing one possibility from the list until we have enough,
* is designed to ensure that raising the barrier rate while
* keeping the seed the same will provide a superset of the
* previous barrier set - i.e. if you ask for 10 barriers, and
* then decide that's still too hard and ask for 20, you'll get
* the original 10 plus 10 more, rather than getting 20 new
* ones and the chance of remembering your first 10.)
*/
nbarriers = (int)(params->barrier_probability * count234(barriertree));
assert(nbarriers >= 0 && nbarriers <= count234(barriertree));
while (nbarriers > 0) {
int i;
struct xyd *xyd;
int x1, y1, d1, x2, y2, d2;
/*
* Extract a randomly chosen barrier from the list.
*/
i = random_upto(rs, count234(barriertree));
xyd = delpos234(barriertree, i);
assert(xyd != NULL);
x1 = xyd->x;
y1 = xyd->y;
d1 = xyd->direction;
sfree(xyd);
OFFSET(x2, y2, x1, y1, d1, params);
d2 = F(d1);
index(params, barriers, x1, y1) |= d1;
index(params, barriers, x2, y2) |= d2;
nbarriers--;
}
/*
* Clean up the rest of the barrier list.
*/
{
struct xyd *xyd;
while ( (xyd = delpos234(barriertree, 0)) != NULL)
sfree(xyd);
freetree234(barriertree);
}
/*
* Finally, encode the grid into a string game description.
*
* My syntax is extremely simple: each square is encoded as a
* hex digit in which bit 0 means a connection on the right,
* bit 1 means up, bit 2 left and bit 3 down. (i.e. the same
* encoding as used internally). Each digit is followed by
* optional barrier indicators: `v' means a vertical barrier to
* the right of it, and `h' means a horizontal barrier below
* it.
*/
desc = snewn(w * h * 3 + 1, char);
p = desc;
for (y = 0; y < h; y++) {
for (x = 0; x < w; x++) {
*p++ = "0123456789abcdef"[index(params, tiles, x, y)];
if ((params->wrapping || x < w-1) &&
(index(params, barriers, x, y) & R))
*p++ = 'v';
if ((params->wrapping || y < h-1) &&
(index(params, barriers, x, y) & D))
*p++ = 'h';
}
}
assert(p - desc <= w*h*3);
*p = '\0';
sfree(tiles);
sfree(barriers);
return desc;
}
static char *validate_desc(game_params *params, char *desc)
{
int w = params->width, h = params->height;
int i;
for (i = 0; i < w*h; i++) {
if (*desc >= '0' && *desc <= '9')
/* OK */;
else if (*desc >= 'a' && *desc <= 'f')
/* OK */;
else if (*desc >= 'A' && *desc <= 'F')
/* OK */;
else if (!*desc)
return "Game description shorter than expected";
else
return "Game description contained unexpected character";
desc++;
while (*desc == 'h' || *desc == 'v')
desc++;
}
if (*desc)
return "Game description longer than expected";
return NULL;
}
/* ----------------------------------------------------------------------
* Construct an initial game state, given a description and parameters.
*/
static game_state *new_game(midend_data *me, game_params *params, char *desc)
{
game_state *state;
int w, h, x, y;
assert(params->width > 0 && params->height > 0);
assert(params->width > 1 || params->height > 1);
/*
* Create a blank game state.
*/
state = snew(game_state);
w = state->width = params->width;
h = state->height = params->height;
state->wrapping = params->wrapping;
state->last_rotate_dir = state->last_rotate_x = state->last_rotate_y = 0;
state->completed = state->used_solve = state->just_used_solve = FALSE;
state->tiles = snewn(state->width * state->height, unsigned char);
memset(state->tiles, 0, state->width * state->height);
state->barriers = snewn(state->width * state->height, unsigned char);
memset(state->barriers, 0, state->width * state->height);
/*
* Parse the game description into the grid.
*/
for (y = 0; y < h; y++) {
for (x = 0; x < w; x++) {
if (*desc >= '0' && *desc <= '9')
tile(state, x, y) = *desc - '0';
else if (*desc >= 'a' && *desc <= 'f')
tile(state, x, y) = *desc - 'a' + 10;
else if (*desc >= 'A' && *desc <= 'F')
tile(state, x, y) = *desc - 'A' + 10;
if (*desc)
desc++;
while (*desc == 'h' || *desc == 'v') {
int x2, y2, d1, d2;
if (*desc == 'v')
d1 = R;
else
d1 = D;
OFFSET(x2, y2, x, y, d1, state);
d2 = F(d1);
barrier(state, x, y) |= d1;
barrier(state, x2, y2) |= d2;
desc++;
}
}
}
/*
* Set up border barriers if this is a non-wrapping game.
*/
if (!state->wrapping) {
for (x = 0; x < state->width; x++) {
barrier(state, x, 0) |= U;
barrier(state, x, state->height-1) |= D;
}
for (y = 0; y < state->height; y++) {
barrier(state, 0, y) |= L;
barrier(state, state->width-1, y) |= R;
}
} else {
/*
* We check whether this is de-facto a non-wrapping game
* despite the parameters, in case we were passed the
* description of a non-wrapping game. This is so that we
* can change some aspects of the UI behaviour.
*/
state->wrapping = FALSE;
for (x = 0; x < state->width; x++)
if (!(barrier(state, x, 0) & U) ||
!(barrier(state, x, state->height-1) & D))
state->wrapping = TRUE;
for (y = 0; y < state->width; y++)
if (!(barrier(state, 0, y) & L) ||
!(barrier(state, state->width-1, y) & R))
state->wrapping = TRUE;
}
return state;
}
static game_state *dup_game(game_state *state)
{
game_state *ret;
ret = snew(game_state);
ret->width = state->width;
ret->height = state->height;
ret->wrapping = state->wrapping;
ret->completed = state->completed;
ret->used_solve = state->used_solve;
ret->just_used_solve = state->just_used_solve;
ret->last_rotate_dir = state->last_rotate_dir;
ret->last_rotate_x = state->last_rotate_x;
ret->last_rotate_y = state->last_rotate_y;
ret->tiles = snewn(state->width * state->height, unsigned char);
memcpy(ret->tiles, state->tiles, state->width * state->height);
ret->barriers = snewn(state->width * state->height, unsigned char);
memcpy(ret->barriers, state->barriers, state->width * state->height);
return ret;
}
static void free_game(game_state *state)
{
sfree(state->tiles);
sfree(state->barriers);
sfree(state);
}
static char *solve_game(game_state *state, game_state *currstate,
char *aux, char **error)
{
unsigned char *tiles;
char *ret;
int retlen, retsize;
int i;
tiles = snewn(state->width * state->height, unsigned char);
if (!aux) {
/*
* Run the internal solver on the provided grid. This might
* not yield a complete solution.
*/
memcpy(tiles, state->tiles, state->width * state->height);
net_solver(state->width, state->height, tiles,
state->barriers, state->wrapping);
} else {
for (i = 0; i < state->width * state->height; i++) {
int c = aux[i];
if (c >= '0' && c <= '9')
tiles[i] = c - '0';
else if (c >= 'a' && c <= 'f')
tiles[i] = c - 'a' + 10;
else if (c >= 'A' && c <= 'F')
tiles[i] = c - 'A' + 10;
}
}
/*
* Now construct a string which can be passed to execute_move()
* to transform the current grid into the solved one.
*/
retsize = 256;
ret = snewn(retsize, char);
retlen = 0;
ret[retlen++] = 'S';
for (i = 0; i < state->width * state->height; i++) {
int from = currstate->tiles[i], to = tiles[i];
int ft = from & (R|L|U|D), tt = to & (R|L|U|D);
int x = i % state->width, y = i / state->width;
int chr = '\0';
char buf[80], *p = buf;
if (from == to)
continue; /* nothing needs doing at all */
/*
* To transform this tile into the desired tile: first
* unlock the tile if it's locked, then rotate it if
* necessary, then lock it if necessary.
*/
if (from & LOCKED)
p += sprintf(p, ";L%d,%d", x, y);
if (tt == A(ft))
chr = 'A';
else if (tt == C(ft))
chr = 'C';
else if (tt == F(ft))
chr = 'F';
else {
assert(tt == ft);
chr = '\0';
}
if (chr)
p += sprintf(p, ";%c%d,%d", chr, x, y);
if (to & LOCKED)
p += sprintf(p, ";L%d,%d", x, y);
if (p > buf) {
if (retlen + (p - buf) >= retsize) {
retsize = retlen + (p - buf) + 512;
ret = sresize(ret, retsize, char);
}
memcpy(ret+retlen, buf, p - buf);
retlen += p - buf;
}
}
assert(retlen < retsize);
ret[retlen] = '\0';
ret = sresize(ret, retlen+1, char);
sfree(tiles);
return ret;
}
static char *game_text_format(game_state *state)
{
return NULL;
}
/* ----------------------------------------------------------------------
* Utility routine.
*/
/*
* Compute which squares are reachable from the centre square, as a
* quick visual aid to determining how close the game is to
* completion. This is also a simple way to tell if the game _is_
* completed - just call this function and see whether every square
* is marked active.
*/
static unsigned char *compute_active(game_state *state, int cx, int cy)
{
unsigned char *active;
tree234 *todo;
struct xyd *xyd;
active = snewn(state->width * state->height, unsigned char);
memset(active, 0, state->width * state->height);
/*
* We only store (x,y) pairs in todo, but it's easier to reuse
* xyd_cmp and just store direction 0 every time.
*/
todo = newtree234(xyd_cmp_nc);
index(state, active, cx, cy) = ACTIVE;
add234(todo, new_xyd(cx, cy, 0));
while ( (xyd = delpos234(todo, 0)) != NULL) {
int x1, y1, d1, x2, y2, d2;
x1 = xyd->x;
y1 = xyd->y;
sfree(xyd);
for (d1 = 1; d1 < 0x10; d1 <<= 1) {
OFFSET(x2, y2, x1, y1, d1, state);
d2 = F(d1);
/*
* If the next tile in this direction is connected to
* us, and there isn't a barrier in the way, and it
* isn't already marked active, then mark it active and
* add it to the to-examine list.
*/
if ((tile(state, x1, y1) & d1) &&
(tile(state, x2, y2) & d2) &&
!(barrier(state, x1, y1) & d1) &&
!index(state, active, x2, y2)) {
index(state, active, x2, y2) = ACTIVE;
add234(todo, new_xyd(x2, y2, 0));
}
}
}
/* Now we expect the todo list to have shrunk to zero size. */
assert(count234(todo) == 0);
freetree234(todo);
return active;
}
struct game_ui {
int org_x, org_y; /* origin */
int cx, cy; /* source tile (game coordinates) */
int cur_x, cur_y;
int cur_visible;
random_state *rs; /* used for jumbling */
};
static game_ui *new_ui(game_state *state)
{
void *seed;
int seedsize;
game_ui *ui = snew(game_ui);
ui->org_x = ui->org_y = 0;
ui->cur_x = ui->cx = state->width / 2;
ui->cur_y = ui->cy = state->height / 2;
ui->cur_visible = FALSE;
get_random_seed(&seed, &seedsize);
ui->rs = random_init(seed, seedsize);
sfree(seed);
return ui;
}
static void free_ui(game_ui *ui)
{
random_free(ui->rs);
sfree(ui);
}
static char *encode_ui(game_ui *ui)
{
char buf[120];
/*
* We preserve the origin and centre-point coordinates over a
* serialise.
*/
sprintf(buf, "O%d,%d;C%d,%d", ui->org_x, ui->org_y, ui->cx, ui->cy);
return dupstr(buf);
}
static void decode_ui(game_ui *ui, char *encoding)
{
sscanf(encoding, "O%d,%d;C%d,%d",
&ui->org_x, &ui->org_y, &ui->cx, &ui->cy);
}
static void game_changed_state(game_ui *ui, game_state *oldstate,
game_state *newstate)
{
}
struct game_drawstate {
int started;
int width, height;
int org_x, org_y;
int tilesize;
unsigned char *visible;
};
/* ----------------------------------------------------------------------
* Process a move.
*/
static char *interpret_move(game_state *state, game_ui *ui,
game_drawstate *ds, int x, int y, int button)
{
char *nullret;
int tx = -1, ty = -1, dir = 0;
int shift = button & MOD_SHFT, ctrl = button & MOD_CTRL;
enum {
NONE, ROTATE_LEFT, ROTATE_180, ROTATE_RIGHT, TOGGLE_LOCK, JUMBLE,
MOVE_ORIGIN, MOVE_SOURCE, MOVE_ORIGIN_AND_SOURCE, MOVE_CURSOR
} action;
button &= ~MOD_MASK;
nullret = NULL;
action = NONE;
if (button == LEFT_BUTTON ||
button == MIDDLE_BUTTON ||
button == RIGHT_BUTTON) {
if (ui->cur_visible) {
ui->cur_visible = FALSE;
nullret = "";
}
/*
* The button must have been clicked on a valid tile.
*/
x -= WINDOW_OFFSET + TILE_BORDER;
y -= WINDOW_OFFSET + TILE_BORDER;
if (x < 0 || y < 0)
return nullret;
tx = x / TILE_SIZE;
ty = y / TILE_SIZE;
if (tx >= state->width || ty >= state->height)
return nullret;
/* Transform from physical to game coords */
tx = (tx + ui->org_x) % state->width;
ty = (ty + ui->org_y) % state->height;
if (x % TILE_SIZE >= TILE_SIZE - TILE_BORDER ||
y % TILE_SIZE >= TILE_SIZE - TILE_BORDER)
return nullret;
action = button == LEFT_BUTTON ? ROTATE_LEFT :
button == RIGHT_BUTTON ? ROTATE_RIGHT : TOGGLE_LOCK;
} else if (button == CURSOR_UP || button == CURSOR_DOWN ||
button == CURSOR_RIGHT || button == CURSOR_LEFT) {
switch (button) {
case CURSOR_UP: dir = U; break;
case CURSOR_DOWN: dir = D; break;
case CURSOR_LEFT: dir = L; break;
case CURSOR_RIGHT: dir = R; break;
default: return nullret;
}
if (shift && ctrl) action = MOVE_ORIGIN_AND_SOURCE;
else if (shift) action = MOVE_ORIGIN;
else if (ctrl) action = MOVE_SOURCE;
else action = MOVE_CURSOR;
} else if (button == 'a' || button == 's' || button == 'd' ||
button == 'A' || button == 'S' || button == 'D' ||
button == 'f' || button == 'F' ||
button == CURSOR_SELECT) {
tx = ui->cur_x;
ty = ui->cur_y;
if (button == 'a' || button == 'A' || button == CURSOR_SELECT)
action = ROTATE_LEFT;
else if (button == 's' || button == 'S')
action = TOGGLE_LOCK;
else if (button == 'd' || button == 'D')
action = ROTATE_RIGHT;
else if (button == 'f' || button == 'F')
action = ROTATE_180;
ui->cur_visible = TRUE;
} else if (button == 'j' || button == 'J') {
/* XXX should we have some mouse control for this? */
action = JUMBLE;
} else
return nullret;
/*
* The middle button locks or unlocks a tile. (A locked tile
* cannot be turned, and is visually marked as being locked.
* This is a convenience for the player, so that once they are
* sure which way round a tile goes, they can lock it and thus
* avoid forgetting later on that they'd already done that one;
* and the locking also prevents them turning the tile by
* accident. If they change their mind, another middle click
* unlocks it.)
*/
if (action == TOGGLE_LOCK) {
char buf[80];
sprintf(buf, "L%d,%d", tx, ty);
return dupstr(buf);
} else if (action == ROTATE_LEFT || action == ROTATE_RIGHT ||
action == ROTATE_180) {
char buf[80];
/*
* The left and right buttons have no effect if clicked on a
* locked tile.
*/
if (tile(state, tx, ty) & LOCKED)
return nullret;
/*
* Otherwise, turn the tile one way or the other. Left button
* turns anticlockwise; right button turns clockwise.
*/
sprintf(buf, "%c%d,%d", (int)(action == ROTATE_LEFT ? 'A' :
action == ROTATE_RIGHT ? 'C' : 'F'), tx, ty);
return dupstr(buf);
} else if (action == JUMBLE) {
/*
* Jumble all unlocked tiles to random orientations.
*/
int jx, jy, maxlen;
char *ret, *p;
/*
* Maximum string length assumes no int can be converted to
* decimal and take more than 11 digits!
*/
maxlen = state->width * state->height * 25 + 3;
ret = snewn(maxlen, char);
p = ret;
*p++ = 'J';
for (jy = 0; jy < state->height; jy++) {
for (jx = 0; jx < state->width; jx++) {
if (!(tile(state, jx, jy) & LOCKED)) {
int rot = random_upto(ui->rs, 4);
if (rot) {
p += sprintf(p, ";%c%d,%d", "AFC"[rot-1], jx, jy);
}
}
}
}
*p++ = '\0';
assert(p - ret < maxlen);
ret = sresize(ret, p - ret, char);
return ret;
} else if (action == MOVE_ORIGIN || action == MOVE_SOURCE ||
action == MOVE_ORIGIN_AND_SOURCE || action == MOVE_CURSOR) {
assert(dir != 0);
if (action == MOVE_ORIGIN || action == MOVE_ORIGIN_AND_SOURCE) {
if (state->wrapping) {
OFFSET(ui->org_x, ui->org_y, ui->org_x, ui->org_y, dir, state);
} else return nullret; /* disallowed for non-wrapping grids */
}
if (action == MOVE_SOURCE || action == MOVE_ORIGIN_AND_SOURCE) {
OFFSET(ui->cx, ui->cy, ui->cx, ui->cy, dir, state);
}
if (action == MOVE_CURSOR) {
OFFSET(ui->cur_x, ui->cur_y, ui->cur_x, ui->cur_y, dir, state);
ui->cur_visible = TRUE;
}
return "";
} else {
return NULL;
}
}
static game_state *execute_move(game_state *from, char *move)
{
game_state *ret;
int tx, ty, n, noanim, orig;
ret = dup_game(from);
ret->just_used_solve = FALSE;
if (move[0] == 'J' || move[0] == 'S') {
if (move[0] == 'S')
ret->just_used_solve = ret->used_solve = TRUE;
move++;
if (*move == ';')
move++;
noanim = TRUE;
} else
noanim = FALSE;
ret->last_rotate_dir = 0; /* suppress animation */
ret->last_rotate_x = ret->last_rotate_y = 0;
while (*move) {
if ((move[0] == 'A' || move[0] == 'C' ||
move[0] == 'F' || move[0] == 'L') &&
sscanf(move+1, "%d,%d%n", &tx, &ty, &n) >= 2 &&
tx >= 0 && tx < from->width && ty >= 0 && ty < from->height) {
orig = tile(ret, tx, ty);
if (move[0] == 'A') {
tile(ret, tx, ty) = A(orig);
if (!noanim)
ret->last_rotate_dir = +1;
} else if (move[0] == 'F') {
tile(ret, tx, ty) = F(orig);
if (!noanim)
ret->last_rotate_dir = +2; /* + for sake of argument */
} else if (move[0] == 'C') {
tile(ret, tx, ty) = C(orig);
if (!noanim)
ret->last_rotate_dir = -1;
} else {
assert(move[0] == 'L');
tile(ret, tx, ty) ^= LOCKED;
}
move += 1 + n;
if (*move == ';') move++;
} else {
free_game(ret);
return NULL;
}
}
if (!noanim) {
ret->last_rotate_x = tx;
ret->last_rotate_y = ty;
}
/*
* Check whether the game has been completed.
*
* For this purpose it doesn't matter where the source square
* is, because we can start from anywhere and correctly
* determine whether the game is completed.
*/
{
unsigned char *active = compute_active(ret, 0, 0);
int x1, y1;
int complete = TRUE;
for (x1 = 0; x1 < ret->width; x1++)
for (y1 = 0; y1 < ret->height; y1++)
if ((tile(ret, x1, y1) & 0xF) && !index(ret, active, x1, y1)) {
complete = FALSE;
goto break_label; /* break out of two loops at once */
}
break_label:
sfree(active);
if (complete)
ret->completed = TRUE;
}
return ret;
}
/* ----------------------------------------------------------------------
* Routines for drawing the game position on the screen.
*/
static game_drawstate *game_new_drawstate(game_state *state)
{
game_drawstate *ds = snew(game_drawstate);
ds->started = FALSE;
ds->width = state->width;
ds->height = state->height;
ds->org_x = ds->org_y = -1;
ds->visible = snewn(state->width * state->height, unsigned char);
ds->tilesize = 0; /* undecided yet */
memset(ds->visible, 0xFF, state->width * state->height);
return ds;
}
static void game_free_drawstate(game_drawstate *ds)
{
sfree(ds->visible);
sfree(ds);
}
static void game_compute_size(game_params *params, int tilesize,
int *x, int *y)
{
*x = WINDOW_OFFSET * 2 + tilesize * params->width + TILE_BORDER;
*y = WINDOW_OFFSET * 2 + tilesize * params->height + TILE_BORDER;
}
static void game_set_size(game_drawstate *ds, game_params *params,
int tilesize)
{
ds->tilesize = tilesize;
}
static float *game_colours(frontend *fe, game_state *state, int *ncolours)
{
float *ret;
ret = snewn(NCOLOURS * 3, float);
*ncolours = NCOLOURS;
/*
* Basic background colour is whatever the front end thinks is
* a sensible default.
*/
frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
/*
* Wires are black.
*/
ret[COL_WIRE * 3 + 0] = 0.0F;
ret[COL_WIRE * 3 + 1] = 0.0F;
ret[COL_WIRE * 3 + 2] = 0.0F;
/*
* Powered wires and powered endpoints are cyan.
*/
ret[COL_POWERED * 3 + 0] = 0.0F;
ret[COL_POWERED * 3 + 1] = 1.0F;
ret[COL_POWERED * 3 + 2] = 1.0F;
/*
* Barriers are red.
*/
ret[COL_BARRIER * 3 + 0] = 1.0F;
ret[COL_BARRIER * 3 + 1] = 0.0F;
ret[COL_BARRIER * 3 + 2] = 0.0F;
/*
* Unpowered endpoints are blue.
*/
ret[COL_ENDPOINT * 3 + 0] = 0.0F;
ret[COL_ENDPOINT * 3 + 1] = 0.0F;
ret[COL_ENDPOINT * 3 + 2] = 1.0F;
/*
* Tile borders are a darker grey than the background.
*/
ret[COL_BORDER * 3 + 0] = 0.5F * ret[COL_BACKGROUND * 3 + 0];
ret[COL_BORDER * 3 + 1] = 0.5F * ret[COL_BACKGROUND * 3 + 1];
ret[COL_BORDER * 3 + 2] = 0.5F * ret[COL_BACKGROUND * 3 + 2];
/*
* Locked tiles are a grey in between those two.
*/
ret[COL_LOCKED * 3 + 0] = 0.75F * ret[COL_BACKGROUND * 3 + 0];
ret[COL_LOCKED * 3 + 1] = 0.75F * ret[COL_BACKGROUND * 3 + 1];
ret[COL_LOCKED * 3 + 2] = 0.75F * ret[COL_BACKGROUND * 3 + 2];
return ret;
}
static void draw_thick_line(frontend *fe, int x1, int y1, int x2, int y2,
int colour)
{
draw_line(fe, x1-1, y1, x2-1, y2, COL_WIRE);
draw_line(fe, x1+1, y1, x2+1, y2, COL_WIRE);
draw_line(fe, x1, y1-1, x2, y2-1, COL_WIRE);
draw_line(fe, x1, y1+1, x2, y2+1, COL_WIRE);
draw_line(fe, x1, y1, x2, y2, colour);
}
static void draw_rect_coords(frontend *fe, int x1, int y1, int x2, int y2,
int colour)
{
int mx = (x1 < x2 ? x1 : x2);
int my = (y1 < y2 ? y1 : y2);
int dx = (x2 + x1 - 2*mx + 1);
int dy = (y2 + y1 - 2*my + 1);
draw_rect(fe, mx, my, dx, dy, colour);
}
/*
* draw_barrier_corner() and draw_barrier() are passed physical coords
*/
static void draw_barrier_corner(frontend *fe, game_drawstate *ds,
int x, int y, int dx, int dy, int phase)
{
int bx = WINDOW_OFFSET + TILE_SIZE * x;
int by = WINDOW_OFFSET + TILE_SIZE * y;
int x1, y1;
x1 = (dx > 0 ? TILE_SIZE+TILE_BORDER-1 : 0);
y1 = (dy > 0 ? TILE_SIZE+TILE_BORDER-1 : 0);
if (phase == 0) {
draw_rect_coords(fe, bx+x1+dx, by+y1,
bx+x1-TILE_BORDER*dx, by+y1-(TILE_BORDER-1)*dy,
COL_WIRE);
draw_rect_coords(fe, bx+x1, by+y1+dy,
bx+x1-(TILE_BORDER-1)*dx, by+y1-TILE_BORDER*dy,
COL_WIRE);
} else {
draw_rect_coords(fe, bx+x1, by+y1,
bx+x1-(TILE_BORDER-1)*dx, by+y1-(TILE_BORDER-1)*dy,
COL_BARRIER);
}
}
static void draw_barrier(frontend *fe, game_drawstate *ds,
int x, int y, int dir, int phase)
{
int bx = WINDOW_OFFSET + TILE_SIZE * x;
int by = WINDOW_OFFSET + TILE_SIZE * y;
int x1, y1, w, h;
x1 = (X(dir) > 0 ? TILE_SIZE : X(dir) == 0 ? TILE_BORDER : 0);
y1 = (Y(dir) > 0 ? TILE_SIZE : Y(dir) == 0 ? TILE_BORDER : 0);
w = (X(dir) ? TILE_BORDER : TILE_SIZE - TILE_BORDER);
h = (Y(dir) ? TILE_BORDER : TILE_SIZE - TILE_BORDER);
if (phase == 0) {
draw_rect(fe, bx+x1-X(dir), by+y1-Y(dir), w, h, COL_WIRE);
} else {
draw_rect(fe, bx+x1, by+y1, w, h, COL_BARRIER);
}
}
/*
* draw_tile() is passed physical coordinates
*/
static void draw_tile(frontend *fe, game_state *state, game_drawstate *ds,
int x, int y, int tile, int src, float angle, int cursor)
{
int bx = WINDOW_OFFSET + TILE_SIZE * x;
int by = WINDOW_OFFSET + TILE_SIZE * y;
float matrix[4];
float cx, cy, ex, ey, tx, ty;
int dir, col, phase;
/*
* When we draw a single tile, we must draw everything up to
* and including the borders around the tile. This means that
* if the neighbouring tiles have connections to those borders,
* we must draw those connections on the borders themselves.
*/
clip(fe, bx, by, TILE_SIZE+TILE_BORDER, TILE_SIZE+TILE_BORDER);
/*
* So. First blank the tile out completely: draw a big
* rectangle in border colour, and a smaller rectangle in
* background colour to fill it in.
*/
draw_rect(fe, bx, by, TILE_SIZE+TILE_BORDER, TILE_SIZE+TILE_BORDER,
COL_BORDER);
draw_rect(fe, bx+TILE_BORDER, by+TILE_BORDER,
TILE_SIZE-TILE_BORDER, TILE_SIZE-TILE_BORDER,
tile & LOCKED ? COL_LOCKED : COL_BACKGROUND);
/*
* Draw an inset outline rectangle as a cursor, in whichever of
* COL_LOCKED and COL_BACKGROUND we aren't currently drawing
* in.
*/
if (cursor) {
draw_line(fe, bx+TILE_SIZE/8, by+TILE_SIZE/8,
bx+TILE_SIZE/8, by+TILE_SIZE-TILE_SIZE/8,
tile & LOCKED ? COL_BACKGROUND : COL_LOCKED);
draw_line(fe, bx+TILE_SIZE/8, by+TILE_SIZE/8,
bx+TILE_SIZE-TILE_SIZE/8, by+TILE_SIZE/8,
tile & LOCKED ? COL_BACKGROUND : COL_LOCKED);
draw_line(fe, bx+TILE_SIZE-TILE_SIZE/8, by+TILE_SIZE/8,
bx+TILE_SIZE-TILE_SIZE/8, by+TILE_SIZE-TILE_SIZE/8,
tile & LOCKED ? COL_BACKGROUND : COL_LOCKED);
draw_line(fe, bx+TILE_SIZE/8, by+TILE_SIZE-TILE_SIZE/8,
bx+TILE_SIZE-TILE_SIZE/8, by+TILE_SIZE-TILE_SIZE/8,
tile & LOCKED ? COL_BACKGROUND : COL_LOCKED);
}
/*
* Set up the rotation matrix.
*/
matrix[0] = (float)cos(angle * PI / 180.0);
matrix[1] = (float)-sin(angle * PI / 180.0);
matrix[2] = (float)sin(angle * PI / 180.0);
matrix[3] = (float)cos(angle * PI / 180.0);
/*
* Draw the wires.
*/
cx = cy = TILE_BORDER + (TILE_SIZE-TILE_BORDER) / 2.0F - 0.5F;
col = (tile & ACTIVE ? COL_POWERED : COL_WIRE);
for (dir = 1; dir < 0x10; dir <<= 1) {
if (tile & dir) {
ex = (TILE_SIZE - TILE_BORDER - 1.0F) / 2.0F * X(dir);
ey = (TILE_SIZE - TILE_BORDER - 1.0F) / 2.0F * Y(dir);
MATMUL(tx, ty, matrix, ex, ey);
draw_thick_line(fe, bx+(int)cx, by+(int)cy,
bx+(int)(cx+tx), by+(int)(cy+ty),
COL_WIRE);
}
}
for (dir = 1; dir < 0x10; dir <<= 1) {
if (tile & dir) {
ex = (TILE_SIZE - TILE_BORDER - 1.0F) / 2.0F * X(dir);
ey = (TILE_SIZE - TILE_BORDER - 1.0F) / 2.0F * Y(dir);
MATMUL(tx, ty, matrix, ex, ey);
draw_line(fe, bx+(int)cx, by+(int)cy,
bx+(int)(cx+tx), by+(int)(cy+ty), col);
}
}
/*
* Draw the box in the middle. We do this in blue if the tile
* is an unpowered endpoint, in cyan if the tile is a powered
* endpoint, in black if the tile is the centrepiece, and
* otherwise not at all.
*/
col = -1;
if (src)
col = COL_WIRE;
else if (COUNT(tile) == 1) {
col = (tile & ACTIVE ? COL_POWERED : COL_ENDPOINT);
}
if (col >= 0) {
int i, points[8];
points[0] = +1; points[1] = +1;
points[2] = +1; points[3] = -1;
points[4] = -1; points[5] = -1;
points[6] = -1; points[7] = +1;
for (i = 0; i < 8; i += 2) {
ex = (TILE_SIZE * 0.24F) * points[i];
ey = (TILE_SIZE * 0.24F) * points[i+1];
MATMUL(tx, ty, matrix, ex, ey);
points[i] = bx+(int)(cx+tx);
points[i+1] = by+(int)(cy+ty);
}
draw_polygon(fe, points, 4, col, COL_WIRE);
}
/*
* Draw the points on the border if other tiles are connected
* to us.
*/
for (dir = 1; dir < 0x10; dir <<= 1) {
int dx, dy, px, py, lx, ly, vx, vy, ox, oy;
dx = X(dir);
dy = Y(dir);
ox = x + dx;
oy = y + dy;
if (ox < 0 || ox >= state->width || oy < 0 || oy >= state->height)
continue;
if (!(tile(state, GX(ox), GY(oy)) & F(dir)))
continue;
px = bx + (int)(dx>0 ? TILE_SIZE + TILE_BORDER - 1 : dx<0 ? 0 : cx);
py = by + (int)(dy>0 ? TILE_SIZE + TILE_BORDER - 1 : dy<0 ? 0 : cy);
lx = dx * (TILE_BORDER-1);
ly = dy * (TILE_BORDER-1);
vx = (dy ? 1 : 0);
vy = (dx ? 1 : 0);
if (angle == 0.0 && (tile & dir)) {
/*
* If we are fully connected to the other tile, we must
* draw right across the tile border. (We can use our
* own ACTIVE state to determine what colour to do this
* in: if we are fully connected to the other tile then
* the two ACTIVE states will be the same.)
*/
draw_rect_coords(fe, px-vx, py-vy, px+lx+vx, py+ly+vy, COL_WIRE);
draw_rect_coords(fe, px, py, px+lx, py+ly,
(tile & ACTIVE) ? COL_POWERED : COL_WIRE);
} else {
/*
* The other tile extends into our border, but isn't
* actually connected to us. Just draw a single black
* dot.
*/
draw_rect_coords(fe, px, py, px, py, COL_WIRE);
}
}
/*
* Draw barrier corners, and then barriers.
*/
for (phase = 0; phase < 2; phase++) {
for (dir = 1; dir < 0x10; dir <<= 1) {
int x1, y1, corner = FALSE;
/*
* If at least one barrier terminates at the corner
* between dir and A(dir), draw a barrier corner.
*/
if (barrier(state, GX(x), GY(y)) & (dir | A(dir))) {
corner = TRUE;
} else {
/*
* Only count barriers terminating at this corner
* if they're physically next to the corner. (That
* is, if they've wrapped round from the far side
* of the screen, they don't count.)
*/
x1 = x + X(dir);
y1 = y + Y(dir);
if (x1 >= 0 && x1 < state->width &&
y1 >= 0 && y1 < state->height &&
(barrier(state, GX(x1), GY(y1)) & A(dir))) {
corner = TRUE;
} else {
x1 = x + X(A(dir));
y1 = y + Y(A(dir));
if (x1 >= 0 && x1 < state->width &&
y1 >= 0 && y1 < state->height &&
(barrier(state, GX(x1), GY(y1)) & dir))
corner = TRUE;
}
}
if (corner) {
/*
* At least one barrier terminates here. Draw a
* corner.
*/
draw_barrier_corner(fe, ds, x, y,
X(dir)+X(A(dir)), Y(dir)+Y(A(dir)),
phase);
}
}
for (dir = 1; dir < 0x10; dir <<= 1)
if (barrier(state, GX(x), GY(y)) & dir)
draw_barrier(fe, ds, x, y, dir, phase);
}
unclip(fe);
draw_update(fe, bx, by, TILE_SIZE+TILE_BORDER, TILE_SIZE+TILE_BORDER);
}
static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate,
game_state *state, int dir, game_ui *ui, float t, float ft)
{
int x, y, tx, ty, frame, last_rotate_dir, moved_origin = FALSE;
unsigned char *active;
float angle = 0.0;
/*
* Clear the screen, and draw the exterior barrier lines, if
* this is our first call or if the origin has changed.
*/
if (!ds->started || ui->org_x != ds->org_x || ui->org_y != ds->org_y) {
int phase;
ds->started = TRUE;
draw_rect(fe, 0, 0,
WINDOW_OFFSET * 2 + TILE_SIZE * state->width + TILE_BORDER,
WINDOW_OFFSET * 2 + TILE_SIZE * state->height + TILE_BORDER,
COL_BACKGROUND);
ds->org_x = ui->org_x;
ds->org_y = ui->org_y;
moved_origin = TRUE;
draw_update(fe, 0, 0,
WINDOW_OFFSET*2 + TILE_SIZE*state->width + TILE_BORDER,
WINDOW_OFFSET*2 + TILE_SIZE*state->height + TILE_BORDER);
for (phase = 0; phase < 2; phase++) {
for (x = 0; x < ds->width; x++) {
if (x+1 < ds->width) {
if (barrier(state, GX(x), GY(0)) & R)
draw_barrier_corner(fe, ds, x, -1, +1, +1, phase);
if (barrier(state, GX(x), GY(ds->height-1)) & R)
draw_barrier_corner(fe, ds, x, ds->height, +1, -1, phase);
}
if (barrier(state, GX(x), GY(0)) & U) {
draw_barrier_corner(fe, ds, x, -1, -1, +1, phase);
draw_barrier_corner(fe, ds, x, -1, +1, +1, phase);
draw_barrier(fe, ds, x, -1, D, phase);
}
if (barrier(state, GX(x), GY(ds->height-1)) & D) {
draw_barrier_corner(fe, ds, x, ds->height, -1, -1, phase);
draw_barrier_corner(fe, ds, x, ds->height, +1, -1, phase);
draw_barrier(fe, ds, x, ds->height, U, phase);
}
}
for (y = 0; y < ds->height; y++) {
if (y+1 < ds->height) {
if (barrier(state, GX(0), GY(y)) & D)
draw_barrier_corner(fe, ds, -1, y, +1, +1, phase);
if (barrier(state, GX(ds->width-1), GY(y)) & D)
draw_barrier_corner(fe, ds, ds->width, y, -1, +1, phase);
}
if (barrier(state, GX(0), GY(y)) & L) {
draw_barrier_corner(fe, ds, -1, y, +1, -1, phase);
draw_barrier_corner(fe, ds, -1, y, +1, +1, phase);
draw_barrier(fe, ds, -1, y, R, phase);
}
if (barrier(state, GX(ds->width-1), GY(y)) & R) {
draw_barrier_corner(fe, ds, ds->width, y, -1, -1, phase);
draw_barrier_corner(fe, ds, ds->width, y, -1, +1, phase);
draw_barrier(fe, ds, ds->width, y, L, phase);
}
}
}
}
tx = ty = -1;
last_rotate_dir = dir==-1 ? oldstate->last_rotate_dir :
state->last_rotate_dir;
if (oldstate && (t < ROTATE_TIME) && last_rotate_dir) {
/*
* We're animating a single tile rotation. Find the turning
* tile.
*/
tx = (dir==-1 ? oldstate->last_rotate_x : state->last_rotate_x);
ty = (dir==-1 ? oldstate->last_rotate_y : state->last_rotate_y);
angle = last_rotate_dir * dir * 90.0F * (t / ROTATE_TIME);
state = oldstate;
}
frame = -1;
if (ft > 0) {
/*
* We're animating a completion flash. Find which frame
* we're at.
*/
frame = (int)(ft / FLASH_FRAME);
}
/*
* Draw any tile which differs from the way it was last drawn.
*/
active = compute_active(state, ui->cx, ui->cy);
for (x = 0; x < ds->width; x++)
for (y = 0; y < ds->height; y++) {
unsigned char c = tile(state, GX(x), GY(y)) |
index(state, active, GX(x), GY(y));
int is_src = GX(x) == ui->cx && GY(y) == ui->cy;
int is_anim = GX(x) == tx && GY(y) == ty;
int is_cursor = ui->cur_visible &&
GX(x) == ui->cur_x && GY(y) == ui->cur_y;
/*
* In a completion flash, we adjust the LOCKED bit
* depending on our distance from the centre point and
* the frame number.
*/
if (frame >= 0) {
int rcx = RX(ui->cx), rcy = RY(ui->cy);
int xdist, ydist, dist;
xdist = (x < rcx ? rcx - x : x - rcx);
ydist = (y < rcy ? rcy - y : y - rcy);
dist = (xdist > ydist ? xdist : ydist);
if (frame >= dist && frame < dist+4) {
int lock = (frame - dist) & 1;
lock = lock ? LOCKED : 0;
c = (c &~ LOCKED) | lock;
}
}
if (moved_origin ||
index(state, ds->visible, x, y) != c ||
index(state, ds->visible, x, y) == 0xFF ||
is_src || is_anim || is_cursor) {
draw_tile(fe, state, ds, x, y, c,
is_src, (is_anim ? angle : 0.0F), is_cursor);
if (is_src || is_anim || is_cursor)
index(state, ds->visible, x, y) = 0xFF;
else
index(state, ds->visible, x, y) = c;
}
}
/*
* Update the status bar.
*/
{
char statusbuf[256];
int i, n, n2, a;
n = state->width * state->height;
for (i = a = n2 = 0; i < n; i++) {
if (active[i])
a++;
if (state->tiles[i] & 0xF)
n2++;
}
sprintf(statusbuf, "%sActive: %d/%d",
(state->used_solve ? "Auto-solved. " :
state->completed ? "COMPLETED! " : ""), a, n2);
status_bar(fe, statusbuf);
}
sfree(active);
}
static float game_anim_length(game_state *oldstate,
game_state *newstate, int dir, game_ui *ui)
{
int last_rotate_dir;
/*
* Don't animate an auto-solve move.
*/
if ((dir > 0 && newstate->just_used_solve) ||
(dir < 0 && oldstate->just_used_solve))
return 0.0F;
/*
* Don't animate if last_rotate_dir is zero.
*/
last_rotate_dir = dir==-1 ? oldstate->last_rotate_dir :
newstate->last_rotate_dir;
if (last_rotate_dir)
return ROTATE_TIME;
return 0.0F;
}
static float game_flash_length(game_state *oldstate,
game_state *newstate, int dir, game_ui *ui)
{
/*
* If the game has just been completed, we display a completion
* flash.
*/
if (!oldstate->completed && newstate->completed &&
!oldstate->used_solve && !newstate->used_solve) {
int size = 0;
if (size < newstate->width)
size = newstate->width;
if (size < newstate->height)
size = newstate->height;
return FLASH_FRAME * (size+4);
}
return 0.0F;
}
static int game_wants_statusbar(void)
{
return TRUE;
}
static int game_timing_state(game_state *state, game_ui *ui)
{
return TRUE;
}
#ifdef COMBINED
#define thegame net
#endif
const struct game thegame = {
"Net", "games.net",
default_params,
game_fetch_preset,
decode_params,
encode_params,
free_params,
dup_params,
TRUE, game_configure, custom_params,
validate_params,
new_game_desc,
validate_desc,
new_game,
dup_game,
free_game,
TRUE, solve_game,
FALSE, game_text_format,
new_ui,
free_ui,
encode_ui,
decode_ui,
game_changed_state,
interpret_move,
execute_move,
PREFERRED_TILE_SIZE, game_compute_size, game_set_size,
game_colours,
game_new_drawstate,
game_free_drawstate,
game_redraw,
game_anim_length,
game_flash_length,
game_wants_statusbar,
FALSE, game_timing_state,
0, /* mouse_priorities */
};
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