ref: 14b434cb88d192a4a5cb2306115dec28cc69e714
dir: /net.c/
/*
* 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"
/*
* The standard user interface for Net simply has left- and
* right-button mouse clicks in a square rotate it one way or the
* other. We also provide, by #ifdef, a separate interface based on
* rotational dragging motions. I initially developed this for the
* Mac on the basis that it might work better than the click
* interface with only one mouse button available, but in fact
* found it to be quite strange and unintuitive. Apparently it
* works better on stylus-driven platforms such as Palm and
* PocketPC, though, so we enable it by default there.
*/
#ifdef STYLUS_BASED
#define USE_DRAGGING
#endif
/* Direction and other bitfields */
#define R 0x01
#define U 0x02
#define L 0x04
#define D 0x08
#define LOCKED 0x10
#define ACTIVE 0x20
#define RERR (R << 6)
#define UERR (U << 6)
#define LERR (L << 6)
#define DERR (D << 6)
#define ERR(dir) ((dir) << 6)
/* 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 LINE_THICK ((TILE_SIZE+47)/48)
#ifdef SMALL_SCREEN
#define WINDOW_OFFSET 4
#else
#define WINDOW_OFFSET 16
#endif
#define ROTATE_TIME 0.13F
#define FLASH_FRAME 0.07F
enum {
COL_BACKGROUND,
COL_LOCKED,
COL_BORDER,
COL_WIRE,
COL_ENDPOINT,
COL_POWERED,
COL_BARRIER,
COL_ERR,
NCOLOURS
};
struct game_params {
int width;
int height;
bool wrapping;
bool unique;
float barrier_probability;
};
typedef struct game_immutable_state {
int refcount;
unsigned char *barriers;
} game_immutable_state;
struct game_state {
int width, height;
bool wrapping, completed;
int last_rotate_x, last_rotate_y, last_rotate_dir;
bool used_solve;
unsigned char *tiles;
struct game_immutable_state *imm;
};
#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)->imm->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},
#ifndef SMALL_SCREEN
{13, 11, false, true, 0.0},
#endif
{5, 5, true, true, 0.0},
{7, 7, true, true, 0.0},
{9, 9, true, true, 0.0},
{11, 11, true, true, 0.0},
#ifndef SMALL_SCREEN
{13, 11, true, true, 0.0},
#endif
};
static bool 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(const game_params *params)
{
game_params *ret = snew(game_params);
*ret = *params; /* structure copy */
return ret;
}
static void decode_params(game_params *ret, char const *string)
{
char const *p = string;
ret->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 = (float)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(const game_params *params, bool 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(const 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].u.string.sval = dupstr(buf);
ret[1].name = "Height";
ret[1].type = C_STRING;
sprintf(buf, "%d", params->height);
ret[1].u.string.sval = dupstr(buf);
ret[2].name = "Walls wrap around";
ret[2].type = C_BOOLEAN;
ret[2].u.boolean.bval = params->wrapping;
ret[3].name = "Barrier probability";
ret[3].type = C_STRING;
sprintf(buf, "%g", params->barrier_probability);
ret[3].u.string.sval = dupstr(buf);
ret[4].name = "Ensure unique solution";
ret[4].type = C_BOOLEAN;
ret[4].u.boolean.bval = params->unique;
ret[5].name = NULL;
ret[5].type = C_END;
return ret;
}
static game_params *custom_params(const config_item *cfg)
{
game_params *ret = snew(game_params);
ret->width = atoi(cfg[0].u.string.sval);
ret->height = atoi(cfg[1].u.string.sval);
ret->wrapping = cfg[2].u.boolean.bval;
ret->barrier_probability = (float)atof(cfg[3].u.string.sval);
ret->unique = cfg[4].u.boolean.bval;
return ret;
}
static const char *validate_params(const game_params *params, bool 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 {
bool *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, bool);
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;
}
/*
* Return values: -1 means puzzle was proved inconsistent, 0 means we
* failed to narrow down to a unique solution, +1 means we solved it
* fully.
*/
static int net_solver(int w, int h, unsigned char *tiles,
unsigned char *barriers, bool wrapping)
{
unsigned char *tilestate;
unsigned char *edgestate;
int *deadends;
int *equivalence;
struct todo *todo;
int i, j, x, y;
int area;
bool 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 = snew_dsf(w * h);
/*
* 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++) {
bool 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
}
if (j == 0) {
/* If we've ruled out all possible orientations for a
* tile, then our puzzle has no solution at all. */
return -1;
}
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 = +1;
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 = 0;
}
}
/*
* 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, bool 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. */
shuffle(perim2, nperim, sizeof(*perim2), rs);
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) {
sfree(perimeter);
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 int *compute_loops_inner(int w, int h, bool wrapping,
const unsigned char *tiles,
const unsigned char *barriers);
static char *new_game_desc(const game_params *params, random_state *rs,
char **aux, bool 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) != 1) {
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.
*
* In order to avoid accidentally generating an already-solved
* grid, we will reshuffle as necessary to ensure that at least
* one edge has a mismatched connection.
*
* This can always be done, since validate_params() enforces a
* grid area of at least 2 and our generator never creates
* either type of rotationally invariant tile (cross and
* blank). Hence there must be at least one edge separating
* distinct tiles, and it must be possible to find orientations
* of those tiles such that one tile is trying to connect
* through that edge and the other is not.
*
* (We could be more subtle, and allow the shuffle to generate
* a grid in which all tiles match up locally and the only
* criterion preventing the grid from being already solved is
* connectedness. However, that would take more effort, and
* it's easier to simply make sure every grid is _obviously_
* not solved.)
*
* We also require that our shuffle produces no loops in the
* initial grid state, because it's a bit rude to light up a 'HEY,
* YOU DID SOMETHING WRONG!' indicator when the user hasn't even
* had a chance to do _anything_ yet. This also is possible just
* by retrying the whole shuffle on failure, because it's clear
* that at least one non-solved shuffle with no loops must exist.
* (Proof: take the _solved_ state of the puzzle, and rotate one
* endpoint.)
*/
while (1) {
int mismatches, prev_loopsquares, this_loopsquares, i;
int *loops;
shuffle:
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);
}
}
/*
* Check for loops, and try to fix them by reshuffling just
* the squares involved.
*/
prev_loopsquares = w*h+1;
while (1) {
loops = compute_loops_inner(w, h, params->wrapping, tiles, NULL);
this_loopsquares = 0;
for (i = 0; i < w*h; i++) {
if (loops[i]) {
int orig = tiles[i];
int rot = random_upto(rs, 4);
tiles[i] = ROT(orig, rot);
this_loopsquares++;
}
}
sfree(loops);
if (this_loopsquares > prev_loopsquares) {
/*
* We're increasing rather than reducing the number of
* loops. Give up and go back to the full shuffle.
*/
goto shuffle;
}
if (this_loopsquares == 0)
break;
prev_loopsquares = this_loopsquares;
}
mismatches = 0;
/*
* I can't even be bothered to check for mismatches across
* a wrapping edge, so I'm just going to enforce that there
* must be a mismatch across a non-wrapping edge, which is
* still always possible.
*/
for (y = 0; y < h; y++) for (x = 0; x < w; x++) {
if (x+1 < w && ((ROT(index(params, tiles, x, y), 2) ^
index(params, tiles, x+1, y)) & L))
mismatches++;
if (y+1 < h && ((ROT(index(params, tiles, x, y), 2) ^
index(params, tiles, x, y+1)) & U))
mismatches++;
}
if (mismatches == 0)
continue;
/* OK. */
break;
}
/*
* 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 const char *validate_desc(const game_params *params, const 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 *me, const game_params *params,
const 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->imm = snew(game_immutable_state);
state->imm->refcount = 1;
state->last_rotate_dir = state->last_rotate_x = state->last_rotate_y = 0;
state->completed = state->used_solve = false;
state->tiles = snewn(state->width * state->height, unsigned char);
memset(state->tiles, 0, state->width * state->height);
state->imm->barriers = snewn(state->width * state->height, unsigned char);
memset(state->imm->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->height; y++)
if (!(barrier(state, 0, y) & L) ||
!(barrier(state, state->width-1, y) & R))
state->wrapping = true;
}
return state;
}
static game_state *dup_game(const game_state *state)
{
game_state *ret;
ret = snew(game_state);
ret->imm = state->imm;
ret->imm->refcount++;
ret->width = state->width;
ret->height = state->height;
ret->wrapping = state->wrapping;
ret->completed = state->completed;
ret->used_solve = state->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);
return ret;
}
static void free_game(game_state *state)
{
if (--state->imm->refcount == 0) {
sfree(state->imm->barriers);
sfree(state->imm);
}
sfree(state->tiles);
sfree(state);
}
static char *solve_game(const game_state *state, const game_state *currstate,
const char *aux, const 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.
*/
int solver_result;
memcpy(tiles, state->tiles, state->width * state->height);
solver_result = net_solver(state->width, state->height, tiles,
state->imm->barriers, state->wrapping);
if (solver_result < 0) {
*error = "No solution exists for this puzzle";
sfree(tiles);
return NULL;
}
} 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;
tiles[i] |= LOCKED;
}
}
/*
* 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 bool game_can_format_as_text_now(const game_params *params)
{
return true;
}
static char *game_text_format(const 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(const 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 net_neighbour_ctx {
int w, h;
const unsigned char *tiles, *barriers;
int i, n, neighbours[4];
};
static int net_neighbour(int vertex, void *vctx)
{
struct net_neighbour_ctx *ctx = (struct net_neighbour_ctx *)vctx;
if (vertex >= 0) {
int x = vertex % ctx->w, y = vertex / ctx->w;
int tile, dir, x1, y1, v1;
ctx->i = ctx->n = 0;
tile = ctx->tiles[vertex];
if (ctx->barriers)
tile &= ~ctx->barriers[vertex];
for (dir = 1; dir < 0x10; dir <<= 1) {
if (!(tile & dir))
continue;
OFFSETWH(x1, y1, x, y, dir, ctx->w, ctx->h);
v1 = y1 * ctx->w + x1;
if (ctx->tiles[v1] & F(dir))
ctx->neighbours[ctx->n++] = v1;
}
}
if (ctx->i < ctx->n)
return ctx->neighbours[ctx->i++];
else
return -1;
}
static int *compute_loops_inner(int w, int h, bool wrapping,
const unsigned char *tiles,
const unsigned char *barriers)
{
struct net_neighbour_ctx ctx;
struct findloopstate *fls;
int *loops;
int x, y;
fls = findloop_new_state(w*h);
ctx.w = w;
ctx.h = h;
ctx.tiles = tiles;
ctx.barriers = barriers;
findloop_run(fls, w*h, net_neighbour, &ctx);
loops = snewn(w*h, int);
for (y = 0; y < h; y++) {
for (x = 0; x < w; x++) {
int x1, y1, dir;
int flags = 0;
for (dir = 1; dir < 0x10; dir <<= 1) {
if ((tiles[y*w+x] & dir) &&
!(barriers && (barriers[y*w+x] & dir))) {
OFFSETWH(x1, y1, x, y, dir, w, h);
if ((tiles[y1*w+x1] & F(dir)) &&
findloop_is_loop_edge(fls, y*w+x, y1*w+x1))
flags |= ERR(dir);
}
}
loops[y*w+x] = flags;
}
}
findloop_free_state(fls);
return loops;
}
static int *compute_loops(const game_state *state)
{
return compute_loops_inner(state->width, state->height, state->wrapping,
state->tiles, state->imm->barriers);
}
struct game_ui {
int org_x, org_y; /* origin */
int cx, cy; /* source tile (game coordinates) */
int cur_x, cur_y;
bool cur_visible;
random_state *rs; /* used for jumbling */
#ifdef USE_DRAGGING
int dragtilex, dragtiley, dragstartx, dragstarty;
bool dragged;
#endif
};
static game_ui *new_ui(const 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_new(seed, seedsize);
sfree(seed);
return ui;
}
static void free_ui(game_ui *ui)
{
random_free(ui->rs);
sfree(ui);
}
static char *encode_ui(const 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, const 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, const game_state *oldstate,
const game_state *newstate)
{
}
struct game_drawstate {
int width, height;
int tilesize;
unsigned long *visible, *to_draw;
};
/* ----------------------------------------------------------------------
* Process a move.
*/
static char *interpret_move(const game_state *state, game_ui *ui,
const game_drawstate *ds,
int x, int y, int button)
{
char *nullret;
int tx = -1, ty = -1, dir = 0;
bool 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 ||
#ifdef USE_DRAGGING
button == LEFT_DRAG ||
button == LEFT_RELEASE ||
button == RIGHT_DRAG ||
button == RIGHT_RELEASE ||
#endif
button == RIGHT_BUTTON) {
if (ui->cur_visible) {
ui->cur_visible = false;
nullret = UI_UPDATE;
}
/*
* The button must have been clicked on a valid tile.
*/
x -= WINDOW_OFFSET + LINE_THICK;
y -= WINDOW_OFFSET + LINE_THICK;
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 - LINE_THICK ||
y % TILE_SIZE >= TILE_SIZE - LINE_THICK)
return nullret;
#ifdef USE_DRAGGING
if (button == MIDDLE_BUTTON
#ifdef STYLUS_BASED
|| button == RIGHT_BUTTON /* with a stylus, `right-click' locks */
#endif
) {
/*
* Middle button never drags: it only toggles the lock.
*/
action = TOGGLE_LOCK;
} else if (button == LEFT_BUTTON
#ifndef STYLUS_BASED
|| button == RIGHT_BUTTON /* (see above) */
#endif
) {
/*
* Otherwise, we note down the start point for a drag.
*/
ui->dragtilex = tx;
ui->dragtiley = ty;
ui->dragstartx = x % TILE_SIZE;
ui->dragstarty = y % TILE_SIZE;
ui->dragged = false;
return nullret; /* no actual action */
} else if (button == LEFT_DRAG
#ifndef STYLUS_BASED
|| button == RIGHT_DRAG
#endif
) {
/*
* Find the new drag point and see if it necessitates a
* rotation.
*/
int x0,y0, xA,yA, xC,yC, xF,yF;
int mx, my;
int d0, dA, dC, dF, dmin;
tx = ui->dragtilex;
ty = ui->dragtiley;
mx = x - (ui->dragtilex * TILE_SIZE);
my = y - (ui->dragtiley * TILE_SIZE);
x0 = ui->dragstartx;
y0 = ui->dragstarty;
xA = ui->dragstarty;
yA = TILE_SIZE-1 - ui->dragstartx;
xF = TILE_SIZE-1 - ui->dragstartx;
yF = TILE_SIZE-1 - ui->dragstarty;
xC = TILE_SIZE-1 - ui->dragstarty;
yC = ui->dragstartx;
d0 = (mx-x0)*(mx-x0) + (my-y0)*(my-y0);
dA = (mx-xA)*(mx-xA) + (my-yA)*(my-yA);
dF = (mx-xF)*(mx-xF) + (my-yF)*(my-yF);
dC = (mx-xC)*(mx-xC) + (my-yC)*(my-yC);
dmin = min(min(d0,dA),min(dF,dC));
if (d0 == dmin) {
return nullret;
} else if (dF == dmin) {
action = ROTATE_180;
ui->dragstartx = xF;
ui->dragstarty = yF;
ui->dragged = true;
} else if (dA == dmin) {
action = ROTATE_LEFT;
ui->dragstartx = xA;
ui->dragstarty = yA;
ui->dragged = true;
} else /* dC == dmin */ {
action = ROTATE_RIGHT;
ui->dragstartx = xC;
ui->dragstarty = yC;
ui->dragged = true;
}
} else if (button == LEFT_RELEASE
#ifndef STYLUS_BASED
|| button == RIGHT_RELEASE
#endif
) {
if (!ui->dragged) {
/*
* There was a click but no perceptible drag:
* revert to single-click behaviour.
*/
tx = ui->dragtilex;
ty = ui->dragtiley;
if (button == LEFT_RELEASE)
action = ROTATE_LEFT;
else
action = ROTATE_RIGHT;
} else
return nullret; /* no action */
}
#else /* USE_DRAGGING */
action = (button == LEFT_BUTTON ? ROTATE_LEFT :
button == RIGHT_BUTTON ? ROTATE_RIGHT : TOGGLE_LOCK);
#endif /* USE_DRAGGING */
} else if (IS_CURSOR_MOVE(button)) {
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' ||
IS_CURSOR_SELECT(button)) {
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' || button == CURSOR_SELECT2)
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 UI_UPDATE;
} else {
return NULL;
}
}
static game_state *execute_move(const game_state *from, const char *move)
{
game_state *ret;
int tx = -1, ty = -1, n, orig;
bool noanim;
ret = dup_game(from);
if (move[0] == 'J' || move[0] == 'S') {
if (move[0] == 'S')
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) {
if (tx == -1 || ty == -1) { free_game(ret); return NULL; }
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 (or, at least, any square
* that's non-empty!), and correctly determine whether the game is
* completed.
*/
{
unsigned char *active;
int pos;
bool complete = true;
for (pos = 0; pos < ret->width * ret->height; pos++)
if (ret->tiles[pos] & 0xF)
break;
if (pos < ret->width * ret->height) {
active = compute_active(ret, pos % ret->width, pos / ret->width);
for (pos = 0; pos < ret->width * ret->height; pos++)
if ((ret->tiles[pos] & 0xF) && !active[pos]) {
complete = false;
break;
}
sfree(active);
}
if (complete)
ret->completed = true;
}
return ret;
}
/* ----------------------------------------------------------------------
* Routines for drawing the game position on the screen.
*/
static game_drawstate *game_new_drawstate(drawing *dr, const game_state *state)
{
game_drawstate *ds = snew(game_drawstate);
int i, ncells;
ds->width = state->width;
ds->height = state->height;
ncells = (state->width+2) * (state->height+2);
ds->visible = snewn(ncells, unsigned long);
ds->to_draw = snewn(ncells, unsigned long);
ds->tilesize = 0; /* undecided yet */
for (i = 0; i < ncells; i++)
ds->visible[i] = -1;
return ds;
}
#define dsindex(ds, field, x, y) ((ds)->field[((y)+1)*((ds)->width+2)+((x)+1)])
#define visible(ds, x, y) dsindex(ds, visible, x, y)
#define todraw(ds, x, y) dsindex(ds, to_draw, x, y)
static void game_free_drawstate(drawing *dr, game_drawstate *ds)
{
sfree(ds->visible);
sfree(ds);
}
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 = WINDOW_OFFSET * 2 + TILE_SIZE * params->width + LINE_THICK;
*y = WINDOW_OFFSET * 2 + TILE_SIZE * params->height + LINE_THICK;
}
static void game_set_size(drawing *dr, game_drawstate *ds,
const game_params *params, int tilesize)
{
ds->tilesize = tilesize;
}
static float *game_colours(frontend *fe, int *ncolours)
{
float *ret;
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;
/*
* Highlighted errors are red as well.
*/
ret[COL_ERR * 3 + 0] = 1.0F;
ret[COL_ERR * 3 + 1] = 0.0F;
ret[COL_ERR * 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 rotated_coords(float *ox, float *oy, const float matrix[4],
float cx, float cy, float ix, float iy)
{
*ox = matrix[0] * ix + matrix[2] * iy + cx;
*oy = matrix[1] * ix + matrix[3] * iy + cy;
}
/* Flags describing the visible features of a tile. */
#define TILE_BARRIER_SHIFT 0 /* 4 bits: R U L D */
#define TILE_BARRIER_CORNER_SHIFT 4 /* 4 bits: RU UL LD DR */
#define TILE_KEYBOARD_CURSOR (1<<8) /* 1 bit if cursor is here */
#define TILE_WIRE_SHIFT 9 /* 8 bits: RR UU LL DD
* Each pair: 0=no wire, 1=unpowered,
* 2=powered, 3=error highlight */
#define TILE_ENDPOINT_SHIFT 17 /* 2 bits: 0=no endpoint, 1=unpowered,
* 2=powered, 3=power-source square */
#define TILE_WIRE_ON_EDGE_SHIFT 19 /* 8 bits: RR UU LL DD,
* same encoding as TILE_WIRE_SHIFT */
#define TILE_ROTATING (1UL<<27) /* 1 bit if tile is rotating */
#define TILE_LOCKED (1UL<<28) /* 1 bit if tile is locked */
static void draw_wires(drawing *dr, int cx, int cy, int radius,
unsigned long tile, int bitmap,
int colour, int halfwidth, const float matrix[4])
{
float fpoints[12*2];
int points[12*2];
int npoints, d, dsh, i;
bool any_wire_this_colour = false;
float xf, yf;
npoints = 0;
for (d = 1, dsh = 0; d < 16; d *= 2, dsh++) {
int wiretype = (tile >> (TILE_WIRE_SHIFT + 2*dsh)) & 3;
fpoints[2*npoints+0] = halfwidth * (X(d) + X(C(d)));
fpoints[2*npoints+1] = halfwidth * (Y(d) + Y(C(d)));
npoints++;
if (bitmap & (1 << wiretype)) {
fpoints[2*npoints+0] = radius * X(d) + halfwidth * X(C(d));
fpoints[2*npoints+1] = radius * Y(d) + halfwidth * Y(C(d));
npoints++;
fpoints[2*npoints+0] = radius * X(d) + halfwidth * X(A(d));
fpoints[2*npoints+1] = radius * Y(d) + halfwidth * Y(A(d));
npoints++;
any_wire_this_colour = true;
}
}
if (!any_wire_this_colour)
return;
for (i = 0; i < npoints; i++) {
rotated_coords(&xf, &yf, matrix, cx, cy, fpoints[2*i], fpoints[2*i+1]);
points[2*i] = 0.5 + xf;
points[2*i+1] = 0.5 + yf;
}
draw_polygon(dr, points, npoints, colour, colour);
}
static void draw_tile(drawing *dr, game_drawstate *ds, int x, int y,
unsigned long tile, float angle)
{
int tx, ty;
int clipx, clipy, clipX, clipY, clipw, cliph;
int border_br = LINE_THICK/2, border_tl = LINE_THICK - border_br;
int barrier_outline_thick = (LINE_THICK+1)/2;
int bg, d, dsh, pass;
int cx, cy, radius;
float matrix[4];
tx = WINDOW_OFFSET + TILE_SIZE * x + border_br;
ty = WINDOW_OFFSET + TILE_SIZE * y + border_br;
/*
* Clip to the tile boundary, with adjustments if we're drawing
* just outside the grid.
*/
clipx = tx; clipX = tx + TILE_SIZE;
clipy = ty; clipY = ty + TILE_SIZE;
if (x == -1) {
clipx = clipX - border_br - barrier_outline_thick;
} else if (x == ds->width) {
clipX = clipx + border_tl + barrier_outline_thick;
}
if (y == -1) {
clipy = clipY - border_br - barrier_outline_thick;
} else if (y == ds->height) {
clipY = clipy + border_tl + barrier_outline_thick;
}
clipw = clipX - clipx;
cliph = clipY - clipy;
clip(dr, clipx, clipy, clipw, cliph);
/*
* Clear the clip region.
*/
bg = (tile & TILE_LOCKED) ? COL_LOCKED : COL_BACKGROUND;
draw_rect(dr, clipx, clipy, clipw, cliph, bg);
/*
* Draw the grid lines.
*/
{
int gridl = (x == -1 ? tx+TILE_SIZE-border_br : tx);
int gridr = (x == ds->width ? tx+border_tl : tx+TILE_SIZE);
int gridu = (y == -1 ? ty+TILE_SIZE-border_br : ty);
int gridd = (y == ds->height ? ty+border_tl : ty+TILE_SIZE);
if (x >= 0)
draw_rect(dr, tx, gridu, border_tl, gridd-gridu, COL_BORDER);
if (y >= 0)
draw_rect(dr, gridl, ty, gridr-gridl, border_tl, COL_BORDER);
if (x < ds->width)
draw_rect(dr, tx+TILE_SIZE-border_br, gridu,
border_br, gridd-gridu, COL_BORDER);
if (y < ds->height)
draw_rect(dr, gridl, ty+TILE_SIZE-border_br,
gridr-gridl, border_br, COL_BORDER);
}
/*
* Draw the keyboard cursor.
*/
if (tile & TILE_KEYBOARD_CURSOR) {
int cursorcol = (tile & TILE_LOCKED) ? COL_BACKGROUND : COL_LOCKED;
int inset_outer = TILE_SIZE/8, inset_inner = inset_outer + LINE_THICK;
draw_rect(dr, tx + inset_outer, ty + inset_outer,
TILE_SIZE - 2*inset_outer, TILE_SIZE - 2*inset_outer,
cursorcol);
draw_rect(dr, tx + inset_inner, ty + inset_inner,
TILE_SIZE - 2*inset_inner, TILE_SIZE - 2*inset_inner,
bg);
}
radius = (TILE_SIZE+1)/2;
cx = tx + radius;
cy = ty + radius;
radius++;
/*
* Draw protrusions into this cell's edges of wires in
* neighbouring cells, as given by the TILE_WIRE_ON_EDGE_SHIFT
* flags. We only draw each of these if there _isn't_ a wire of
* our own that's going to overlap it, which means either the
* corresponding TILE_WIRE_SHIFT flag is zero, or else the
* TILE_ROTATING flag is set (so that our main wire won't be drawn
* in quite that place anyway).
*/
for (d = 1, dsh = 0; d < 16; d *= 2, dsh++) {
int edgetype = ((tile >> (TILE_WIRE_ON_EDGE_SHIFT + 2*dsh)) & 3);
if (edgetype == 0)
continue; /* there isn't a wire on the edge */
if (!(tile & TILE_ROTATING) &&
((tile >> (TILE_WIRE_SHIFT + 2*dsh)) & 3) != 0)
continue; /* wire on edge would be overdrawn anyway */
for (pass = 0; pass < 2; pass++) {
int x, y, w, h;
int col = (pass == 0 || edgetype == 1 ? COL_WIRE :
edgetype == 2 ? COL_POWERED : COL_ERR);
int halfwidth = pass == 0 ? 2*LINE_THICK-1 : LINE_THICK-1;
if (X(d) < 0) {
x = tx;
w = border_tl;
} else if (X(d) > 0) {
x = tx + TILE_SIZE - border_br;
w = border_br;
} else {
x = cx - halfwidth;
w = 2 * halfwidth + 1;
}
if (Y(d) < 0) {
y = ty;
h = border_tl;
} else if (Y(d) > 0) {
y = ty + TILE_SIZE - border_br;
h = border_br;
} else {
y = cy - halfwidth;
h = 2 * halfwidth + 1;
}
draw_rect(dr, x, y, w, h, col);
}
}
/*
* Set up the rotation matrix for the main cell contents, i.e.
* everything that is centred in the grid square and optionally
* rotated by an arbitrary angle about that centre point.
*/
if (tile & TILE_ROTATING) {
matrix[0] = (float)cos(angle * PI / 180.0);
matrix[2] = (float)sin(angle * PI / 180.0);
} else {
matrix[0] = 1.0F;
matrix[2] = 0.0F;
}
matrix[3] = matrix[0];
matrix[1] = -matrix[2];
/*
* Draw the wires.
*/
draw_wires(dr, cx, cy, radius, tile,
0xE, COL_WIRE, 2*LINE_THICK-1, matrix);
draw_wires(dr, cx, cy, radius, tile,
0x4, COL_POWERED, LINE_THICK-1, matrix);
draw_wires(dr, cx, cy, radius, tile,
0x8, COL_ERR, LINE_THICK-1, matrix);
/*
* Draw the central box.
*/
for (pass = 0; pass < 2; pass++) {
int endtype = (tile >> TILE_ENDPOINT_SHIFT) & 3;
if (endtype) {
int i, points[8], col;
float boxr = TILE_SIZE * 0.24F + (pass == 0 ? LINE_THICK-1 : 0);
col = (pass == 0 || endtype == 3 ? COL_WIRE :
endtype == 2 ? COL_POWERED : COL_ENDPOINT);
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) {
float x, y;
rotated_coords(&x, &y, matrix, cx, cy,
boxr * points[i], boxr * points[i+1]);
points[i] = x + 0.5;
points[i+1] = y + 0.5;
}
draw_polygon(dr, points, 4, col, COL_WIRE);
}
}
/*
* Draw barriers along grid edges.
*/
for (pass = 0; pass < 2; pass++) {
int btl = border_tl, bbr = border_br, col = COL_BARRIER;
if (pass == 0) {
btl += barrier_outline_thick;
bbr += barrier_outline_thick;
col = COL_WIRE;
}
if (tile & (L << TILE_BARRIER_SHIFT))
draw_rect(dr, tx, ty, btl, TILE_SIZE, col);
if (tile & (R << TILE_BARRIER_SHIFT))
draw_rect(dr, tx+TILE_SIZE-bbr, ty, bbr, TILE_SIZE, col);
if (tile & (U << TILE_BARRIER_SHIFT))
draw_rect(dr, tx, ty, TILE_SIZE, btl, col);
if (tile & (D << TILE_BARRIER_SHIFT))
draw_rect(dr, tx, ty+TILE_SIZE-bbr, TILE_SIZE, bbr, col);
if (tile & (R << TILE_BARRIER_CORNER_SHIFT))
draw_rect(dr, tx+TILE_SIZE-bbr, ty, bbr, btl, col);
if (tile & (U << TILE_BARRIER_CORNER_SHIFT))
draw_rect(dr, tx, ty, btl, btl, col);
if (tile & (L << TILE_BARRIER_CORNER_SHIFT))
draw_rect(dr, tx, ty+TILE_SIZE-bbr, btl, bbr, col);
if (tile & (D << TILE_BARRIER_CORNER_SHIFT))
draw_rect(dr, tx+TILE_SIZE-bbr, ty+TILE_SIZE-bbr, bbr, bbr, col);
}
/*
* Unclip and draw update, to finish.
*/
unclip(dr);
draw_update(dr, clipx, clipy, clipw, cliph);
}
static void game_redraw(drawing *dr, game_drawstate *ds,
const game_state *oldstate, const game_state *state,
int dir, const game_ui *ui,
float t, float ft)
{
int tx, ty, dx, dy, d, dsh, last_rotate_dir, frame;
unsigned char *active;
int *loops;
float angle = 0.0;
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;
}
if (ft > 0) {
/*
* We're animating a completion flash. Find which frame
* we're at.
*/
frame = (int)(ft / FLASH_FRAME);
} else {
frame = 0;
}
/*
* Build up a map of what we want every tile to look like. We
* include tiles one square outside the grid, for the outer edges
* of barriers.
*/
active = compute_active(state, ui->cx, ui->cy);
loops = compute_loops(state);
for (dy = -1; dy < ds->height+1; dy++) {
for (dx = -1; dx < ds->width+1; dx++) {
todraw(ds, dx, dy) = 0;
}
}
for (dy = 0; dy < ds->height; dy++) {
int gy = (dy + ui->org_y) % ds->height;
for (dx = 0; dx < ds->width; dx++) {
int gx = (dx + ui->org_x) % ds->width;
int t = (tile(state, gx, gy) |
index(state, loops, gx, gy) |
index(state, active, gx, gy));
for (d = 1, dsh = 0; d < 16; d *= 2, dsh++) {
if (barrier(state, gx, gy) & d) {
todraw(ds, dx, dy) |=
d << TILE_BARRIER_SHIFT;
todraw(ds, dx + X(d), dy + Y(d)) |=
F(d) << TILE_BARRIER_SHIFT;
todraw(ds, dx + X(A(d)), dy + Y(A(d))) |=
C(d) << TILE_BARRIER_CORNER_SHIFT;
todraw(ds, dx + X(A(d)) + X(d), dy + Y(A(d)) + Y(d)) |=
F(d) << TILE_BARRIER_CORNER_SHIFT;
todraw(ds, dx + X(C(d)), dy + Y(C(d))) |=
d << TILE_BARRIER_CORNER_SHIFT;
todraw(ds, dx + X(C(d)) + X(d), dy + Y(C(d)) + Y(d)) |=
A(d) << TILE_BARRIER_CORNER_SHIFT;
}
if (t & d) {
int edgeval;
/* Highlight as an error any edge in a locked tile that
* is adjacent to a lack-of-edge in another locked tile,
* or to a barrier */
if (t & LOCKED) {
if (barrier(state, gx, gy) & d) {
t |= ERR(d);
} else {
int ox, oy, t2;
OFFSET(ox, oy, gx, gy, d, state);
t2 = tile(state, ox, oy);
if ((t2 & LOCKED) && !(t2 & F(d))) {
t |= ERR(d);
}
}
}
edgeval = (t & ERR(d) ? 3 : t & ACTIVE ? 2 : 1);
todraw(ds, dx, dy) |= edgeval << (TILE_WIRE_SHIFT + dsh*2);
if (!(gx == tx && gy == ty)) {
todraw(ds, dx + X(d), dy + Y(d)) |=
edgeval << (TILE_WIRE_ON_EDGE_SHIFT + (dsh ^ 2)*2);
}
}
}
if (ui->cur_visible && gx == ui->cur_x && gy == ui->cur_y)
todraw(ds, dx, dy) |= TILE_KEYBOARD_CURSOR;
if (gx == tx && gy == ty)
todraw(ds, dx, dy) |= TILE_ROTATING;
if (gx == ui->cx && gy == ui->cy) {
todraw(ds, dx, dy) |= 3 << TILE_ENDPOINT_SHIFT;
} else if ((t & 0xF) != R && (t & 0xF) != U &&
(t & 0xF) != L && (t & 0xF) != D) {
/* this is not an endpoint tile */
} else if (t & ACTIVE) {
todraw(ds, dx, dy) |= 2 << TILE_ENDPOINT_SHIFT;
} else {
todraw(ds, dx, dy) |= 1 << TILE_ENDPOINT_SHIFT;
}
if (t & LOCKED)
todraw(ds, dx, dy) |= TILE_LOCKED;
/*
* 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 = (ui->cx + ds->width - ui->org_x) % ds->width;
int rcy = (ui->cy + ds->height - ui->org_y) % ds->height;
int xdist, ydist, dist;
xdist = (dx < rcx ? rcx - dx : dx - rcx);
ydist = (dy < rcy ? rcy - dy : dy - rcy);
dist = (xdist > ydist ? xdist : ydist);
if (frame >= dist && frame < dist+4 &&
((frame - dist) & 1))
todraw(ds, dx, dy) ^= TILE_LOCKED;
}
}
}
/*
* Now draw any tile that differs from the way it was last drawn.
* An exception is that if either the previous _or_ current state
* has the TILE_ROTATING bit set, we must draw it regardless,
* because it will have rotated to a different angle.q
*/
for (dy = -1; dy < ds->height+1; dy++) {
for (dx = -1; dx < ds->width+1; dx++) {
int prev = visible(ds, dx, dy);
int curr = todraw(ds, dx, dy);
if (prev != curr || ((prev | curr) & TILE_ROTATING) != 0) {
draw_tile(dr, ds, dx, dy, curr, angle);
visible(ds, dx, dy) = curr;
}
}
}
/*
* Update the status bar.
*/
{
char statusbuf[256], *p;
int i, n, n2, a;
bool complete = false;
p = statusbuf;
*p = '\0'; /* ensure even an empty status string is terminated */
if (state->used_solve) {
p += sprintf(p, "Auto-solved. ");
complete = true;
} else if (state->completed) {
p += sprintf(p, "COMPLETED! ");
complete = true;
}
/*
* Omit the 'Active: n/N' counter completely if the source
* tile is a completely empty one, because then the active
* count can't help but read '1'.
*/
if (tile(state, ui->cx, ui->cy) & 0xF) {
n = state->width * state->height;
for (i = a = n2 = 0; i < n; i++) {
if (active[i])
a++;
if (state->tiles[i] & 0xF)
n2++;
}
/*
* Also, if we're displaying a completion indicator and
* the game is still in its completed state (i.e. every
* tile is active), we might as well omit this too.
*/
if (!complete || a < n2)
p += sprintf(p, "Active: %d/%d", a, n2);
}
status_bar(dr, statusbuf);
}
sfree(active);
sfree(loops);
}
static float game_anim_length(const game_state *oldstate,
const game_state *newstate, int dir, game_ui *ui)
{
int last_rotate_dir;
/*
* 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(const game_state *oldstate,
const 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 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 = WINDOW_OFFSET + TILE_SIZE * ui->cur_x;
*y = WINDOW_OFFSET + TILE_SIZE * ui->cur_y;
*w = *h = TILE_SIZE;
}
}
static int game_status(const game_state *state)
{
return state->completed ? +1 : 0;
}
static bool game_timing_state(const game_state *state, game_ui *ui)
{
return true;
}
static void game_print_size(const game_params *params, float *x, float *y)
{
int pw, ph;
/*
* I'll use 8mm squares by default.
*/
game_compute_size(params, 800, &pw, &ph);
*x = pw / 100.0F;
*y = ph / 100.0F;
}
static void draw_diagram(drawing *dr, game_drawstate *ds, int x, int y,
bool topleft, int v, bool drawlines, int ink)
{
int tx, ty, cx, cy, r, br, k, thick;
tx = WINDOW_OFFSET + TILE_SIZE * x;
ty = WINDOW_OFFSET + TILE_SIZE * y;
/*
* Find our centre point.
*/
if (topleft) {
cx = tx + (v & L ? TILE_SIZE / 4 : TILE_SIZE / 6);
cy = ty + (v & U ? TILE_SIZE / 4 : TILE_SIZE / 6);
r = TILE_SIZE / 8;
br = TILE_SIZE / 32;
} else {
cx = tx + TILE_SIZE / 2;
cy = ty + TILE_SIZE / 2;
r = TILE_SIZE / 2;
br = TILE_SIZE / 8;
}
thick = r / 20;
/*
* Draw the square block if we have an endpoint.
*/
if (v == 1 || v == 2 || v == 4 || v == 8)
draw_rect(dr, cx - br, cy - br, br*2, br*2, ink);
/*
* Draw each radial line.
*/
if (drawlines) {
for (k = 1; k < 16; k *= 2)
if (v & k) {
int x1 = min(cx, cx + (r-thick) * X(k));
int x2 = max(cx, cx + (r-thick) * X(k));
int y1 = min(cy, cy + (r-thick) * Y(k));
int y2 = max(cy, cy + (r-thick) * Y(k));
draw_rect(dr, x1 - thick, y1 - thick,
(x2 - x1) + 2*thick, (y2 - y1) + 2*thick, ink);
}
}
}
static void game_print(drawing *dr, const game_state *state, int tilesize)
{
int w = state->width, h = state->height;
int ink = print_mono_colour(dr, 0);
int x, y;
/* Ick: fake up `ds->tilesize' for macro expansion purposes */
game_drawstate ads, *ds = &ads;
game_set_size(dr, ds, NULL, tilesize);
/*
* Border.
*/
print_line_width(dr, TILE_SIZE / (state->wrapping ? 128 : 12));
draw_rect_outline(dr, WINDOW_OFFSET, WINDOW_OFFSET,
TILE_SIZE * w, TILE_SIZE * h, ink);
/*
* Grid.
*/
print_line_width(dr, TILE_SIZE / 128);
for (x = 1; x < w; x++)
draw_line(dr, WINDOW_OFFSET + TILE_SIZE * x, WINDOW_OFFSET,
WINDOW_OFFSET + TILE_SIZE * x, WINDOW_OFFSET + TILE_SIZE * h,
ink);
for (y = 1; y < h; y++)
draw_line(dr, WINDOW_OFFSET, WINDOW_OFFSET + TILE_SIZE * y,
WINDOW_OFFSET + TILE_SIZE * w, WINDOW_OFFSET + TILE_SIZE * y,
ink);
/*
* Barriers.
*/
for (y = 0; y <= h; y++)
for (x = 0; x <= w; x++) {
int b = barrier(state, x % w, y % h);
if (x < w && (b & U))
draw_rect(dr, WINDOW_OFFSET + TILE_SIZE * x - TILE_SIZE/24,
WINDOW_OFFSET + TILE_SIZE * y - TILE_SIZE/24,
TILE_SIZE + TILE_SIZE/24 * 2, TILE_SIZE/24 * 2, ink);
if (y < h && (b & L))
draw_rect(dr, WINDOW_OFFSET + TILE_SIZE * x - TILE_SIZE/24,
WINDOW_OFFSET + TILE_SIZE * y - TILE_SIZE/24,
TILE_SIZE/24 * 2, TILE_SIZE + TILE_SIZE/24 * 2, ink);
}
/*
* Grid contents.
*/
for (y = 0; y < h; y++)
for (x = 0; x < w; x++) {
int vx, v = tile(state, x, y);
int locked = v & LOCKED;
v &= 0xF;
/*
* Rotate into a standard orientation for the top left
* corner diagram.
*/
vx = v;
while (vx != 0 && vx != 15 && vx != 1 && vx != 9 && vx != 13 &&
vx != 5)
vx = A(vx);
/*
* Draw the top left corner diagram.
*/
draw_diagram(dr, ds, x, y, true, vx, true, ink);
/*
* Draw the real solution diagram, if we're doing so.
*/
draw_diagram(dr, ds, x, y, false, v, locked, ink);
}
}
#ifdef COMBINED
#define thegame net
#endif
const struct game thegame = {
"Net", "games.net", "net",
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, game_can_format_as_text_now, game_text_format,
new_ui,
free_ui,
encode_ui,
decode_ui,
NULL, /* game_request_keys */
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_get_cursor_location,
game_status,
true, false, game_print_size, game_print,
true, /* wants_statusbar */
false, game_timing_state,
0, /* flags */
};