ref: 100cfd2e994fe870af1bd247097dfc105291c1bd
dir: /unfinished/slide.c/
/*
* slide.c: Implementation of the block-sliding puzzle `Klotski'.
*/
/*
* TODO:
*
* - Improve the generator.
* * actually, we seem to be mostly sensible already now. I
* want more choice over the type of main block and location
* of the exit/target, and I think I probably ought to give
* up on compactness and just bite the bullet and have the
* target area right outside the main wall, but mostly I
* think it's OK.
* * the move limit tends to make the game _slower_ to
* generate, which is odd. Perhaps investigate why.
*
* - Improve the graphics.
* * All the colours are a bit wishy-washy. _Some_ dark
* colours would surely not be excessive? Probably darken
* the tiles, the walls and the main block, and leave the
* target marker pale.
* * The cattle grid effect is still disgusting. Think of
* something completely different.
* * The highlight for next-piece-to-move in the solver is
* excessive, and the shadow blends in too well with the
* piece lowlights. Adjust both.
*/
#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 implementation of this game revolves around the insight
* which makes an exhaustive-search solver feasible: although
* there are many blocks which can be rearranged in many ways, any
* two blocks of the same shape are _indistinguishable_ and hence
* the number of _distinct_ board layouts is generally much
* smaller. So we adopt a representation for board layouts which
* is inherently canonical, i.e. there are no two distinct
* representations which encode indistinguishable layouts.
*
* The way we do this is to encode each square of the board, in
* the normal left-to-right top-to-bottom order, as being one of
* the following things:
* - the first square (in the given order) of a block (`anchor')
* - special case of the above: the anchor for the _main_ block
* (i.e. the one which the aim of the game is to get to the
* target position)
* - a subsequent square of a block whose previous square was N
* squares ago
* - an impassable wall
*
* (We also separately store data about which board positions are
* forcefields only passable by the main block. We can't encode
* that in the main board data, because then the main block would
* destroy forcefields as it went over them.)
*
* Hence, for example, a 2x2 square block would be encoded as
* ANCHOR, followed by DIST(1), and w-2 squares later on there
* would be DIST(w-1) followed by DIST(1). So if you start at the
* last of those squares, the DIST numbers give you a linked list
* pointing back through all the other squares in the same block.
*
* So the solver simply does a bfs over all reachable positions,
* encoding them in this format and storing them in a tree234 to
* ensure it doesn't ever revisit an already-analysed position.
*/
enum {
/*
* The colours are arranged here so that every base colour is
* directly followed by its highlight colour and then its
* lowlight colour. Do not break this, or draw_tile() will get
* confused.
*/
COL_BACKGROUND,
COL_HIGHLIGHT,
COL_LOWLIGHT,
COL_DRAGGING,
COL_DRAGGING_HIGHLIGHT,
COL_DRAGGING_LOWLIGHT,
COL_MAIN,
COL_MAIN_HIGHLIGHT,
COL_MAIN_LOWLIGHT,
COL_MAIN_DRAGGING,
COL_MAIN_DRAGGING_HIGHLIGHT,
COL_MAIN_DRAGGING_LOWLIGHT,
COL_TARGET,
COL_TARGET_HIGHLIGHT,
COL_TARGET_LOWLIGHT,
NCOLOURS
};
/*
* Board layout is a simple array of bytes. Each byte holds:
*/
#define ANCHOR 255 /* top-left-most square of some piece */
#define MAINANCHOR 254 /* anchor of _main_ piece */
#define EMPTY 253 /* empty square */
#define WALL 252 /* immovable wall */
#define MAXDIST 251
/* all other values indicate distance back to previous square of same block */
#define ISDIST(x) ( (unsigned char)((x)-1) <= MAXDIST-1 )
#define DIST(x) (x)
#define ISANCHOR(x) ( (x)==ANCHOR || (x)==MAINANCHOR )
#define ISBLOCK(x) ( ISANCHOR(x) || ISDIST(x) )
/*
* MAXDIST is the largest DIST value we can encode. This must
* therefore also be the maximum puzzle width in theory (although
* solver running time will dictate a much smaller limit in
* practice).
*/
#define MAXWID MAXDIST
struct game_params {
int w, h;
int maxmoves;
};
struct game_immutable_state {
int refcount;
bool *forcefield;
};
struct game_solution {
int nmoves;
int *moves; /* just like from solve_board() */
int refcount;
};
struct game_state {
int w, h;
unsigned char *board;
int tx, ty; /* target coords for MAINANCHOR */
int minmoves; /* for display only */
int lastmoved, lastmoved_pos; /* for move counting */
int movecount;
int completed;
bool cheated;
struct game_immutable_state *imm;
struct game_solution *soln;
int soln_index;
};
static game_params *default_params(void)
{
game_params *ret = snew(game_params);
ret->w = 7;
ret->h = 6;
ret->maxmoves = 40;
return ret;
}
static const struct game_params slide_presets[] = {
{7, 6, 25},
{7, 6, -1},
{8, 6, -1},
};
static bool game_fetch_preset(int i, char **name, game_params **params)
{
game_params *ret;
char str[80];
if (i < 0 || i >= lenof(slide_presets))
return false;
ret = snew(game_params);
*ret = slide_presets[i];
sprintf(str, "%dx%d", ret->w, ret->h);
if (ret->maxmoves >= 0)
sprintf(str + strlen(str), ", max %d moves", ret->maxmoves);
else
sprintf(str + strlen(str), ", no move limit");
*name = dupstr(str);
*params = ret;
return true;
}
static void free_params(game_params *params)
{
sfree(params);
}
static game_params *dup_params(const game_params *params)
{
game_params *ret = snew(game_params);
*ret = *params; /* structure copy */
return ret;
}
static void decode_params(game_params *params, char const *string)
{
params->w = params->h = atoi(string);
while (*string && isdigit((unsigned char)*string)) string++;
if (*string == 'x') {
string++;
params->h = atoi(string);
while (*string && isdigit((unsigned char)*string)) string++;
}
if (*string == 'm') {
string++;
params->maxmoves = atoi(string);
while (*string && isdigit((unsigned char)*string)) string++;
} else if (*string == 'u') {
string++;
params->maxmoves = -1;
}
}
static char *encode_params(const game_params *params, bool full)
{
char data[256];
sprintf(data, "%dx%d", params->w, params->h);
if (params->maxmoves >= 0)
sprintf(data + strlen(data), "m%d", params->maxmoves);
else
sprintf(data + strlen(data), "u");
return dupstr(data);
}
static config_item *game_configure(const game_params *params)
{
config_item *ret;
char buf[80];
ret = snewn(4, config_item);
ret[0].name = "Width";
ret[0].type = C_STRING;
sprintf(buf, "%d", params->w);
ret[0].u.string.sval = dupstr(buf);
ret[1].name = "Height";
ret[1].type = C_STRING;
sprintf(buf, "%d", params->h);
ret[1].u.string.sval = dupstr(buf);
ret[2].name = "Solution length limit";
ret[2].type = C_STRING;
sprintf(buf, "%d", params->maxmoves);
ret[2].u.string.sval = dupstr(buf);
ret[3].name = NULL;
ret[3].type = C_END;
return ret;
}
static game_params *custom_params(const config_item *cfg)
{
game_params *ret = snew(game_params);
ret->w = atoi(cfg[0].u.string.sval);
ret->h = atoi(cfg[1].u.string.sval);
ret->maxmoves = atoi(cfg[2].u.string.sval);
return ret;
}
static const char *validate_params(const game_params *params, bool full)
{
if (params->w > MAXWID)
return "Width must be at most " STR(MAXWID);
if (params->w < 5)
return "Width must be at least 5";
if (params->h < 4)
return "Height must be at least 4";
return NULL;
}
static char *board_text_format(int w, int h, unsigned char *data,
bool *forcefield)
{
int wh = w*h;
int *dsf = snew_dsf(wh);
int i, x, y;
int retpos, retlen = (w*2+2)*(h*2+1)+1;
char *ret = snewn(retlen, char);
for (i = 0; i < wh; i++)
if (ISDIST(data[i]))
dsf_merge(dsf, i - data[i], i);
retpos = 0;
for (y = 0; y < 2*h+1; y++) {
for (x = 0; x < 2*w+1; x++) {
int v;
int i = (y/2)*w+(x/2);
#define dtype(i) (ISBLOCK(data[i]) ? \
dsf_canonify(dsf, i) : data[i])
#define dchar(t) ((t)==EMPTY ? ' ' : (t)==WALL ? '#' : \
data[t] == MAINANCHOR ? '*' : '%')
if (y % 2 && x % 2) {
int j = dtype(i);
v = dchar(j);
} else if (y % 2 && !(x % 2)) {
int j1 = (x > 0 ? dtype(i-1) : -1);
int j2 = (x < 2*w ? dtype(i) : -1);
if (j1 != j2)
v = '|';
else
v = dchar(j1);
} else if (!(y % 2) && (x % 2)) {
int j1 = (y > 0 ? dtype(i-w) : -1);
int j2 = (y < 2*h ? dtype(i) : -1);
if (j1 != j2)
v = '-';
else
v = dchar(j1);
} else {
int j1 = (x > 0 && y > 0 ? dtype(i-w-1) : -1);
int j2 = (x > 0 && y < 2*h ? dtype(i-1) : -1);
int j3 = (x < 2*w && y > 0 ? dtype(i-w) : -1);
int j4 = (x < 2*w && y < 2*h ? dtype(i) : -1);
if (j1 == j2 && j2 == j3 && j3 == j4)
v = dchar(j1);
else if (j1 == j2 && j3 == j4)
v = '|';
else if (j1 == j3 && j2 == j4)
v = '-';
else
v = '+';
}
assert(retpos < retlen);
ret[retpos++] = v;
}
assert(retpos < retlen);
ret[retpos++] = '\n';
}
assert(retpos < retlen);
ret[retpos++] = '\0';
assert(retpos == retlen);
return ret;
}
/* ----------------------------------------------------------------------
* Solver.
*/
/*
* During solver execution, the set of visited board positions is
* stored as a tree234 of the following structures. `w', `h' and
* `data' are obvious in meaning; `dist' represents the minimum
* distance to reach this position from the starting point.
*
* `prev' links each board to the board position from which it was
* most efficiently derived.
*/
struct board {
int w, h;
int dist;
struct board *prev;
unsigned char *data;
};
static int boardcmp(void *av, void *bv)
{
struct board *a = (struct board *)av;
struct board *b = (struct board *)bv;
return memcmp(a->data, b->data, a->w * a->h);
}
static struct board *newboard(int w, int h, unsigned char *data)
{
struct board *b = malloc(sizeof(struct board) + w*h);
b->data = (unsigned char *)b + sizeof(struct board);
memcpy(b->data, data, w*h);
b->w = w;
b->h = h;
b->dist = -1;
b->prev = NULL;
return b;
}
/*
* The actual solver. Given a board, attempt to find the minimum
* length of move sequence which moves MAINANCHOR to (tx,ty), or
* -1 if no solution exists. Returns that minimum length.
*
* Also, if `moveout' is provided, writes out the moves in the
* form of a sequence of pairs of integers indicating the source
* and destination points of the anchor of the moved piece in each
* move. Exactly twice as many integers are written as the number
* returned from solve_board(), and `moveout' receives an int *
* which is a pointer to a dynamically allocated array.
*/
static int solve_board(int w, int h, unsigned char *board,
bool *forcefield, int tx, int ty,
int movelimit, int **moveout)
{
int wh = w*h;
struct board *b, *b2, *b3;
int *next, *which;
bool *anchors, *movereached;
int *movequeue, mqhead, mqtail;
tree234 *sorted, *queue;
int i, j, dir;
int qlen, lastdist;
int ret;
#ifdef SOLVER_DIAGNOSTICS
{
char *t = board_text_format(w, h, board);
for (i = 0; i < h; i++) {
for (j = 0; j < w; j++) {
int c = board[i*w+j];
if (ISDIST(c))
printf("D%-3d", c);
else if (c == MAINANCHOR)
printf("M ");
else if (c == ANCHOR)
printf("A ");
else if (c == WALL)
printf("W ");
else if (c == EMPTY)
printf("E ");
}
printf("\n");
}
printf("Starting solver for:\n%s\n", t);
sfree(t);
}
#endif
sorted = newtree234(boardcmp);
queue = newtree234(NULL);
b = newboard(w, h, board);
b->dist = 0;
add234(sorted, b);
addpos234(queue, b, 0);
qlen = 1;
next = snewn(wh, int);
anchors = snewn(wh, bool);
which = snewn(wh, int);
movereached = snewn(wh, bool);
movequeue = snewn(wh, int);
lastdist = -1;
while ((b = delpos234(queue, 0)) != NULL) {
qlen--;
if (movelimit >= 0 && b->dist >= movelimit) {
/*
* The problem is not soluble in under `movelimit'
* moves, so we can quit right now.
*/
b2 = NULL;
goto done;
}
if (b->dist != lastdist) {
#ifdef SOLVER_DIAGNOSTICS
printf("dist %d (%d)\n", b->dist, count234(sorted));
#endif
lastdist = b->dist;
}
/*
* Find all the anchors and form a linked list of the
* squares within each block.
*/
for (i = 0; i < wh; i++) {
next[i] = -1;
anchors[i] = false;
which[i] = -1;
if (ISANCHOR(b->data[i])) {
anchors[i] = true;
which[i] = i;
} else if (ISDIST(b->data[i])) {
j = i - b->data[i];
next[j] = i;
which[i] = which[j];
}
}
/*
* For each anchor, do an array-based BFS to find all the
* places we can slide it to.
*/
for (i = 0; i < wh; i++) {
if (!anchors[i])
continue;
mqhead = mqtail = 0;
for (j = 0; j < wh; j++)
movereached[j] = false;
movequeue[mqtail++] = i;
while (mqhead < mqtail) {
int pos = movequeue[mqhead++];
/*
* Try to move in each direction from here.
*/
for (dir = 0; dir < 4; dir++) {
int dx = (dir == 0 ? -1 : dir == 1 ? +1 : 0);
int dy = (dir == 2 ? -1 : dir == 3 ? +1 : 0);
int offset = dy*w + dx;
int newpos = pos + offset;
int d = newpos - i;
/*
* For each square involved in this block,
* check to see if the square d spaces away
* from it is either empty or part of the same
* block.
*/
for (j = i; j >= 0; j = next[j]) {
int jy = (pos+j-i) / w + dy, jx = (pos+j-i) % w + dx;
if (jy >= 0 && jy < h && jx >= 0 && jx < w &&
((b->data[j+d] == EMPTY || which[j+d] == i) &&
(b->data[i] == MAINANCHOR || !forcefield[j+d])))
/* ok */;
else
break;
}
if (j >= 0)
continue; /* this direction wasn't feasible */
/*
* If we've already tried moving this piece
* here, leave it.
*/
if (movereached[newpos])
continue;
movereached[newpos] = true;
movequeue[mqtail++] = newpos;
/*
* We have a viable move. Make it.
*/
b2 = newboard(w, h, b->data);
for (j = i; j >= 0; j = next[j])
b2->data[j] = EMPTY;
for (j = i; j >= 0; j = next[j])
b2->data[j+d] = b->data[j];
b3 = add234(sorted, b2);
if (b3 != b2) {
sfree(b2); /* we already got one */
} else {
b2->dist = b->dist + 1;
b2->prev = b;
addpos234(queue, b2, qlen++);
if (b2->data[ty*w+tx] == MAINANCHOR)
goto done; /* search completed! */
}
}
}
}
}
b2 = NULL;
done:
if (b2) {
ret = b2->dist;
if (moveout) {
/*
* Now b2 represents the solved position. Backtrack to
* output the solution.
*/
*moveout = snewn(ret * 2, int);
j = ret * 2;
while (b2->prev) {
int from = -1, to = -1;
b = b2->prev;
/*
* Scan b and b2 to find out which piece has
* moved.
*/
for (i = 0; i < wh; i++) {
if (ISANCHOR(b->data[i]) && !ISANCHOR(b2->data[i])) {
assert(from == -1);
from = i;
} else if (!ISANCHOR(b->data[i]) && ISANCHOR(b2->data[i])){
assert(to == -1);
to = i;
}
}
assert(from >= 0 && to >= 0);
assert(j >= 2);
(*moveout)[--j] = to;
(*moveout)[--j] = from;
b2 = b;
}
assert(j == 0);
}
} else {
ret = -1; /* no solution */
if (moveout)
*moveout = NULL;
}
freetree234(queue);
while ((b = delpos234(sorted, 0)) != NULL)
sfree(b);
freetree234(sorted);
sfree(next);
sfree(anchors);
sfree(movereached);
sfree(movequeue);
sfree(which);
return ret;
}
/* ----------------------------------------------------------------------
* Random board generation.
*/
static void generate_board(int w, int h, int *rtx, int *rty, int *minmoves,
random_state *rs, unsigned char **rboard,
bool **rforcefield, int movelimit)
{
int wh = w*h;
unsigned char *board, *board2;
bool *forcefield;
bool *tried_merge;
int *dsf;
int *list, nlist, pos;
int tx, ty;
int i, j;
int moves = 0; /* placate optimiser */
/*
* Set up a board and fill it with singletons, except for a
* border of walls.
*/
board = snewn(wh, unsigned char);
forcefield = snewn(wh, bool);
board2 = snewn(wh, unsigned char);
memset(board, ANCHOR, wh);
memset(forcefield, 0, wh * sizeof(bool));
for (i = 0; i < w; i++)
board[i] = board[i+w*(h-1)] = WALL;
for (i = 0; i < h; i++)
board[i*w] = board[i*w+(w-1)] = WALL;
tried_merge = snewn(wh * wh, bool);
memset(tried_merge, 0, wh*wh * sizeof(bool));
dsf = snew_dsf(wh);
/*
* Invent a main piece at one extreme. (FIXME: vary the
* extreme, and the piece.)
*/
board[w+1] = MAINANCHOR;
board[w+2] = DIST(1);
board[w*2+1] = DIST(w-1);
board[w*2+2] = DIST(1);
/*
* Invent a target position. (FIXME: vary this too.)
*/
tx = w-2;
ty = h-3;
forcefield[ty*w+tx+1] = true;
forcefield[(ty+1)*w+tx+1] = true;
board[ty*w+tx+1] = board[(ty+1)*w+tx+1] = EMPTY;
/*
* Gradually remove singletons until the game becomes soluble.
*/
for (j = w; j-- > 0 ;)
for (i = h; i-- > 0 ;)
if (board[i*w+j] == ANCHOR) {
/*
* See if the board is already soluble.
*/
if ((moves = solve_board(w, h, board, forcefield,
tx, ty, movelimit, NULL)) >= 0)
goto soluble;
/*
* Otherwise, remove this piece.
*/
board[i*w+j] = EMPTY;
}
assert(!"We shouldn't get here");
soluble:
/*
* Make a list of all the inter-block edges on the board.
*/
list = snewn(wh*2, int);
nlist = 0;
for (i = 0; i+1 < w; i++)
for (j = 0; j < h; j++)
list[nlist++] = (j*w+i) * 2 + 0; /* edge to the right of j*w+i */
for (j = 0; j+1 < h; j++)
for (i = 0; i < w; i++)
list[nlist++] = (j*w+i) * 2 + 1; /* edge below j*w+i */
/*
* Now go through that list in random order, trying to merge
* the blocks on each side of each edge.
*/
shuffle(list, nlist, sizeof(*list), rs);
while (nlist > 0) {
int x1, y1, p1, c1;
int x2, y2, p2, c2;
pos = list[--nlist];
y1 = y2 = pos / (w*2);
x1 = x2 = (pos / 2) % w;
if (pos % 2)
y2++;
else
x2++;
p1 = y1*w+x1;
p2 = y2*w+x2;
/*
* Immediately abandon the attempt if we've already tried
* to merge the same pair of blocks along a different
* edge.
*/
c1 = dsf_canonify(dsf, p1);
c2 = dsf_canonify(dsf, p2);
if (tried_merge[c1 * wh + c2])
continue;
/*
* In order to be mergeable, these two squares must each
* either be, or belong to, a non-main anchor, and their
* anchors must also be distinct.
*/
if (!ISBLOCK(board[p1]) || !ISBLOCK(board[p2]))
continue;
while (ISDIST(board[p1]))
p1 -= board[p1];
while (ISDIST(board[p2]))
p2 -= board[p2];
if (board[p1] == MAINANCHOR || board[p2] == MAINANCHOR || p1 == p2)
continue;
/*
* We can merge these blocks. Try it, and see if the
* puzzle remains soluble.
*/
memcpy(board2, board, wh);
j = -1;
while (p1 < wh || p2 < wh) {
/*
* p1 and p2 are the squares at the head of each block
* list. Pick the smaller one and put it on the output
* block list.
*/
i = min(p1, p2);
if (j < 0) {
board[i] = ANCHOR;
} else {
assert(i - j <= MAXDIST);
board[i] = DIST(i - j);
}
j = i;
/*
* Now advance whichever list that came from.
*/
if (i == p1) {
do {
p1++;
} while (p1 < wh && board[p1] != DIST(p1-i));
} else {
do {
p2++;
} while (p2 < wh && board[p2] != DIST(p2-i));
}
}
j = solve_board(w, h, board, forcefield, tx, ty, movelimit, NULL);
if (j < 0) {
/*
* Didn't work. Revert the merge.
*/
memcpy(board, board2, wh);
tried_merge[c1 * wh + c2] = true;
tried_merge[c2 * wh + c1] = true;
} else {
int c;
moves = j;
dsf_merge(dsf, c1, c2);
c = dsf_canonify(dsf, c1);
for (i = 0; i < wh; i++)
tried_merge[c*wh+i] = (tried_merge[c1*wh+i] ||
tried_merge[c2*wh+i]);
for (i = 0; i < wh; i++)
tried_merge[i*wh+c] = (tried_merge[i*wh+c1] ||
tried_merge[i*wh+c2]);
}
}
sfree(dsf);
sfree(list);
sfree(tried_merge);
sfree(board2);
*rtx = tx;
*rty = ty;
*rboard = board;
*rforcefield = forcefield;
*minmoves = moves;
}
/* ----------------------------------------------------------------------
* End of solver/generator code.
*/
static char *new_game_desc(const game_params *params, random_state *rs,
char **aux, bool interactive)
{
int w = params->w, h = params->h, wh = w*h;
int tx, ty, minmoves;
unsigned char *board;
bool *forcefield;
char *ret, *p;
int i;
generate_board(params->w, params->h, &tx, &ty, &minmoves, rs,
&board, &forcefield, params->maxmoves);
#ifdef GENERATOR_DIAGNOSTICS
{
char *t = board_text_format(params->w, params->h, board);
printf("%s\n", t);
sfree(t);
}
#endif
/*
* Encode as a game ID.
*/
ret = snewn(wh * 6 + 40, char);
p = ret;
i = 0;
while (i < wh) {
if (ISDIST(board[i])) {
p += sprintf(p, "d%d", board[i]);
i++;
} else {
int count = 1;
int b = board[i];
bool f = forcefield[i];
int c = (b == ANCHOR ? 'a' :
b == MAINANCHOR ? 'm' :
b == EMPTY ? 'e' :
/* b == WALL ? */ 'w');
if (f) *p++ = 'f';
*p++ = c;
i++;
while (i < wh && board[i] == b && forcefield[i] == f)
i++, count++;
if (count > 1)
p += sprintf(p, "%d", count);
}
}
p += sprintf(p, ",%d,%d,%d", tx, ty, minmoves);
ret = sresize(ret, p+1 - ret, char);
sfree(board);
sfree(forcefield);
return ret;
}
static const char *validate_desc(const game_params *params, const char *desc)
{
int w = params->w, h = params->h, wh = w*h;
bool *active;
int *link;
int mains = 0;
int i, tx, ty, minmoves;
const char *ret;
active = snewn(wh, bool);
link = snewn(wh, int);
i = 0;
while (*desc && *desc != ',') {
if (i >= wh) {
ret = "Too much data in game description";
goto done;
}
link[i] = -1;
active[i] = false;
if (*desc == 'f' || *desc == 'F') {
desc++;
if (!*desc) {
ret = "Expected another character after 'f' in game "
"description";
goto done;
}
}
if (*desc == 'd' || *desc == 'D') {
int dist;
desc++;
if (!isdigit((unsigned char)*desc)) {
ret = "Expected a number after 'd' in game description";
goto done;
}
dist = atoi(desc);
while (*desc && isdigit((unsigned char)*desc)) desc++;
if (dist <= 0 || dist > i) {
ret = "Out-of-range number after 'd' in game description";
goto done;
}
if (!active[i - dist]) {
ret = "Invalid back-reference in game description";
goto done;
}
link[i] = i - dist;
active[i] = true;
active[link[i]] = false;
i++;
} else {
int c = *desc++;
int count = 1;
if (!strchr("aAmMeEwW", c)) {
ret = "Invalid character in game description";
goto done;
}
if (isdigit((unsigned char)*desc)) {
count = atoi(desc);
while (*desc && isdigit((unsigned char)*desc)) desc++;
}
if (i + count > wh) {
ret = "Too much data in game description";
goto done;
}
while (count-- > 0) {
active[i] = (strchr("aAmM", c) != NULL);
link[i] = -1;
if (strchr("mM", c) != NULL) {
mains++;
}
i++;
}
}
}
if (mains != 1) {
ret = (mains == 0 ? "No main piece specified in game description" :
"More than one main piece specified in game description");
goto done;
}
if (i < wh) {
ret = "Not enough data in game description";
goto done;
}
/*
* Now read the target coordinates.
*/
i = sscanf(desc, ",%d,%d,%d", &tx, &ty, &minmoves);
if (i < 2) {
ret = "No target coordinates specified";
goto done;
/*
* (but minmoves is optional)
*/
}
ret = NULL;
done:
sfree(active);
sfree(link);
return ret;
}
static game_state *new_game(midend *me, const game_params *params,
const char *desc)
{
int w = params->w, h = params->h, wh = w*h;
game_state *state;
int i;
state = snew(game_state);
state->w = w;
state->h = h;
state->board = snewn(wh, unsigned char);
state->lastmoved = state->lastmoved_pos = -1;
state->movecount = 0;
state->imm = snew(struct game_immutable_state);
state->imm->refcount = 1;
state->imm->forcefield = snewn(wh, bool);
i = 0;
while (*desc && *desc != ',') {
bool f = false;
assert(i < wh);
if (*desc == 'f') {
f = true;
desc++;
assert(*desc);
}
if (*desc == 'd' || *desc == 'D') {
int dist;
desc++;
dist = atoi(desc);
while (*desc && isdigit((unsigned char)*desc)) desc++;
state->board[i] = DIST(dist);
state->imm->forcefield[i] = f;
i++;
} else {
int c = *desc++;
int count = 1;
if (isdigit((unsigned char)*desc)) {
count = atoi(desc);
while (*desc && isdigit((unsigned char)*desc)) desc++;
}
assert(i + count <= wh);
c = (c == 'a' || c == 'A' ? ANCHOR :
c == 'm' || c == 'M' ? MAINANCHOR :
c == 'e' || c == 'E' ? EMPTY :
/* c == 'w' || c == 'W' ? */ WALL);
while (count-- > 0) {
state->board[i] = c;
state->imm->forcefield[i] = f;
i++;
}
}
}
/*
* Now read the target coordinates.
*/
state->tx = state->ty = 0;
state->minmoves = -1;
i = sscanf(desc, ",%d,%d,%d", &state->tx, &state->ty, &state->minmoves);
if (state->board[state->ty*w+state->tx] == MAINANCHOR)
state->completed = 0; /* already complete! */
else
state->completed = -1;
state->cheated = false;
state->soln = NULL;
state->soln_index = -1;
return state;
}
static game_state *dup_game(const game_state *state)
{
int w = state->w, h = state->h, wh = w*h;
game_state *ret = snew(game_state);
ret->w = state->w;
ret->h = state->h;
ret->board = snewn(wh, unsigned char);
memcpy(ret->board, state->board, wh);
ret->tx = state->tx;
ret->ty = state->ty;
ret->minmoves = state->minmoves;
ret->lastmoved = state->lastmoved;
ret->lastmoved_pos = state->lastmoved_pos;
ret->movecount = state->movecount;
ret->completed = state->completed;
ret->cheated = state->cheated;
ret->imm = state->imm;
ret->imm->refcount++;
ret->soln = state->soln;
ret->soln_index = state->soln_index;
if (ret->soln)
ret->soln->refcount++;
return ret;
}
static void free_game(game_state *state)
{
if (--state->imm->refcount <= 0) {
sfree(state->imm->forcefield);
sfree(state->imm);
}
if (state->soln && --state->soln->refcount <= 0) {
sfree(state->soln->moves);
sfree(state->soln);
}
sfree(state->board);
sfree(state);
}
static char *solve_game(const game_state *state, const game_state *currstate,
const char *aux, const char **error)
{
int *moves;
int nmoves;
int i;
char *ret, *p, sep;
/*
* Run the solver and attempt to find the shortest solution
* from the current position.
*/
nmoves = solve_board(state->w, state->h, state->board,
state->imm->forcefield, state->tx, state->ty,
-1, &moves);
if (nmoves < 0) {
*error = "Unable to find a solution to this puzzle";
return NULL;
}
if (nmoves == 0) {
*error = "Puzzle is already solved";
return NULL;
}
/*
* Encode the resulting solution as a move string.
*/
ret = snewn(nmoves * 40, char);
p = ret;
sep = 'S';
for (i = 0; i < nmoves; i++) {
p += sprintf(p, "%c%d-%d", sep, moves[i*2], moves[i*2+1]);
sep = ',';
}
sfree(moves);
assert(p - ret < nmoves * 40);
ret = sresize(ret, p+1 - ret, char);
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 board_text_format(state->w, state->h, state->board,
state->imm->forcefield);
}
struct game_ui {
bool dragging;
int drag_anchor;
int drag_offset_x, drag_offset_y;
int drag_currpos;
bool *reachable;
int *bfs_queue; /* used as scratch in interpret_move */
};
static game_ui *new_ui(const game_state *state)
{
int w = state->w, h = state->h, wh = w*h;
game_ui *ui = snew(game_ui);
ui->dragging = false;
ui->drag_anchor = ui->drag_currpos = -1;
ui->drag_offset_x = ui->drag_offset_y = -1;
ui->reachable = snewn(wh, bool);
memset(ui->reachable, 0, wh * sizeof(bool));
ui->bfs_queue = snewn(wh, int);
return ui;
}
static void free_ui(game_ui *ui)
{
sfree(ui->bfs_queue);
sfree(ui->reachable);
sfree(ui);
}
static char *encode_ui(const game_ui *ui)
{
return NULL;
}
static void decode_ui(game_ui *ui, const char *encoding)
{
}
static void game_changed_state(game_ui *ui, const game_state *oldstate,
const game_state *newstate)
{
}
#define PREFERRED_TILESIZE 32
#define TILESIZE (ds->tilesize)
#define BORDER (TILESIZE/2)
#define COORD(x) ( (x) * TILESIZE + BORDER )
#define FROMCOORD(x) ( ((x) - BORDER + TILESIZE) / TILESIZE - 1 )
#define BORDER_WIDTH (1 + TILESIZE/20)
#define HIGHLIGHT_WIDTH (1 + TILESIZE/16)
#define FLASH_INTERVAL 0.10F
#define FLASH_TIME 3*FLASH_INTERVAL
struct game_drawstate {
int tilesize;
int w, h;
unsigned long *grid; /* what's currently displayed */
};
static char *interpret_move(const game_state *state, game_ui *ui,
const game_drawstate *ds,
int x, int y, int button)
{
int w = state->w, h = state->h, wh = w*h;
int tx, ty, i, j;
int qhead, qtail;
if (button == LEFT_BUTTON) {
tx = FROMCOORD(x);
ty = FROMCOORD(y);
if (tx < 0 || tx >= w || ty < 0 || ty >= h ||
!ISBLOCK(state->board[ty*w+tx]))
return NULL; /* this click has no effect */
/*
* User has clicked on a block. Find the block's anchor
* and register that we've started dragging it.
*/
i = ty*w+tx;
while (ISDIST(state->board[i]))
i -= state->board[i];
assert(i >= 0 && i < wh);
ui->dragging = true;
ui->drag_anchor = i;
ui->drag_offset_x = tx - (i % w);
ui->drag_offset_y = ty - (i / w);
ui->drag_currpos = i;
/*
* Now we immediately bfs out from the current location of
* the anchor, to find all the places to which this block
* can be dragged.
*/
memset(ui->reachable, 0, wh * sizeof(bool));
qhead = qtail = 0;
ui->reachable[i] = true;
ui->bfs_queue[qtail++] = i;
for (j = i; j < wh; j++)
if (state->board[j] == DIST(j - i))
i = j;
while (qhead < qtail) {
int pos = ui->bfs_queue[qhead++];
int x = pos % w, y = pos / w;
int dir;
for (dir = 0; dir < 4; dir++) {
int dx = (dir == 0 ? -1 : dir == 1 ? +1 : 0);
int dy = (dir == 2 ? -1 : dir == 3 ? +1 : 0);
int newpos;
if (x + dx < 0 || x + dx >= w ||
y + dy < 0 || y + dy >= h)
continue;
newpos = pos + dy*w + dx;
if (ui->reachable[newpos])
continue; /* already done this one */
/*
* Now search the grid to see if the block we're
* dragging could fit into this space.
*/
for (j = i; j >= 0; j = (ISDIST(state->board[j]) ?
j - state->board[j] : -1)) {
int jx = (j+pos-ui->drag_anchor) % w;
int jy = (j+pos-ui->drag_anchor) / w;
int j2;
if (jx + dx < 0 || jx + dx >= w ||
jy + dy < 0 || jy + dy >= h)
break; /* this position isn't valid at all */
j2 = (j+pos-ui->drag_anchor) + dy*w + dx;
if (state->board[j2] == EMPTY &&
(!state->imm->forcefield[j2] ||
state->board[ui->drag_anchor] == MAINANCHOR))
continue;
while (ISDIST(state->board[j2]))
j2 -= state->board[j2];
assert(j2 >= 0 && j2 < wh);
if (j2 == ui->drag_anchor)
continue;
else
break;
}
if (j < 0) {
/*
* If we got to the end of that loop without
* disqualifying this position, mark it as
* reachable for this drag.
*/
ui->reachable[newpos] = true;
ui->bfs_queue[qtail++] = newpos;
}
}
}
/*
* And that's it. Update the display to reflect the start
* of a drag.
*/
return UI_UPDATE;
} else if (button == LEFT_DRAG && ui->dragging) {
int dist, distlimit, dx, dy, s, px, py;
tx = FROMCOORD(x);
ty = FROMCOORD(y);
tx -= ui->drag_offset_x;
ty -= ui->drag_offset_y;
/*
* Now search outwards from (tx,ty), in order of Manhattan
* distance, until we find a reachable square.
*/
distlimit = w+tx;
distlimit = max(distlimit, h+ty);
distlimit = max(distlimit, tx);
distlimit = max(distlimit, ty);
for (dist = 0; dist <= distlimit; dist++) {
for (dx = -dist; dx <= dist; dx++)
for (s = -1; s <= +1; s += 2) {
dy = s * (dist - abs(dx));
px = tx + dx;
py = ty + dy;
if (px >= 0 && px < w && py >= 0 && py < h &&
ui->reachable[py*w+px]) {
ui->drag_currpos = py*w+px;
return UI_UPDATE;
}
}
}
return NULL; /* give up - this drag has no effect */
} else if (button == LEFT_RELEASE && ui->dragging) {
char data[256], *str;
/*
* Terminate the drag, and if the piece has actually moved
* then return a move string quoting the old and new
* locations of the piece's anchor.
*/
if (ui->drag_anchor != ui->drag_currpos) {
sprintf(data, "M%d-%d", ui->drag_anchor, ui->drag_currpos);
str = dupstr(data);
} else
str = UI_UPDATE;
ui->dragging = false;
ui->drag_anchor = ui->drag_currpos = -1;
ui->drag_offset_x = ui->drag_offset_y = -1;
memset(ui->reachable, 0, wh * sizeof(bool));
return str;
} else if (button == ' ' && state->soln) {
/*
* Make the next move in the stored solution.
*/
char data[256];
int a1, a2;
a1 = state->soln->moves[state->soln_index*2];
a2 = state->soln->moves[state->soln_index*2+1];
if (a1 == state->lastmoved_pos)
a1 = state->lastmoved;
sprintf(data, "M%d-%d", a1, a2);
return dupstr(data);
}
return NULL;
}
static bool move_piece(int w, int h, const unsigned char *src,
unsigned char *dst, bool *ff, int from, int to)
{
int wh = w*h;
int i, j;
if (!ISANCHOR(dst[from]))
return false;
/*
* Scan to the far end of the piece's linked list.
*/
for (i = j = from; j < wh; j++)
if (src[j] == DIST(j - i))
i = j;
/*
* Remove the piece from its old location in the new
* game state.
*/
for (j = i; j >= 0; j = (ISDIST(src[j]) ? j - src[j] : -1))
dst[j] = EMPTY;
/*
* And put it back in at the new location.
*/
for (j = i; j >= 0; j = (ISDIST(src[j]) ? j - src[j] : -1)) {
int jn = j + to - from;
if (jn < 0 || jn >= wh)
return false;
if (dst[jn] == EMPTY && (!ff[jn] || src[from] == MAINANCHOR)) {
dst[jn] = src[j];
} else {
return false;
}
}
return true;
}
static game_state *execute_move(const game_state *state, const char *move)
{
int w = state->w, h = state->h /* , wh = w*h */;
char c;
int a1, a2, n, movesize;
game_state *ret = dup_game(state);
while (*move) {
c = *move;
if (c == 'S') {
/*
* This is a solve move, so we just set up a stored
* solution path.
*/
if (ret->soln && --ret->soln->refcount <= 0) {
sfree(ret->soln->moves);
sfree(ret->soln);
}
ret->soln = snew(struct game_solution);
ret->soln->nmoves = 0;
ret->soln->moves = NULL;
ret->soln->refcount = 1;
ret->soln_index = 0;
ret->cheated = true;
movesize = 0;
move++;
while (1) {
if (sscanf(move, "%d-%d%n", &a1, &a2, &n) != 2) {
free_game(ret);
return NULL;
}
/*
* Special case: if the first move in the solution
* involves the piece for which we already have a
* partial stored move, adjust the source point to
* the original starting point of that piece.
*/
if (ret->soln->nmoves == 0 && a1 == ret->lastmoved)
a1 = ret->lastmoved_pos;
if (ret->soln->nmoves >= movesize) {
movesize = (ret->soln->nmoves + 48) * 4 / 3;
ret->soln->moves = sresize(ret->soln->moves,
2*movesize, int);
}
ret->soln->moves[2*ret->soln->nmoves] = a1;
ret->soln->moves[2*ret->soln->nmoves+1] = a2;
ret->soln->nmoves++;
move += n;
if (*move != ',')
break;
move++; /* eat comma */
}
} else if (c == 'M') {
move++;
if (sscanf(move, "%d-%d%n", &a1, &a2, &n) != 2 ||
!move_piece(w, h, state->board, ret->board,
state->imm->forcefield, a1, a2)) {
free_game(ret);
return NULL;
}
if (a1 == ret->lastmoved) {
/*
* If the player has moved the same piece as they
* moved last time, don't increment the move
* count. In fact, if they've put the piece back
* where it started from, _decrement_ the move
* count.
*/
if (a2 == ret->lastmoved_pos) {
ret->movecount--; /* reverted last move */
ret->lastmoved = ret->lastmoved_pos = -1;
} else {
ret->lastmoved = a2;
/* don't change lastmoved_pos */
}
} else {
ret->lastmoved = a2;
ret->lastmoved_pos = a1;
ret->movecount++;
}
/*
* If we have a stored solution path, see if we've
* strayed from it or successfully made the next move
* along it.
*/
if (ret->soln && ret->lastmoved_pos >= 0) {
if (ret->lastmoved_pos !=
ret->soln->moves[ret->soln_index*2]) {
/* strayed from the path */
ret->soln->refcount--;
assert(ret->soln->refcount > 0);
/* `state' at least still exists */
ret->soln = NULL;
ret->soln_index = -1;
} else if (ret->lastmoved ==
ret->soln->moves[ret->soln_index*2+1]) {
/* advanced along the path */
ret->soln_index++;
if (ret->soln_index >= ret->soln->nmoves) {
/* finished the path! */
ret->soln->refcount--;
assert(ret->soln->refcount > 0);
/* `state' at least still exists */
ret->soln = NULL;
ret->soln_index = -1;
}
}
}
if (ret->board[a2] == MAINANCHOR &&
a2 == ret->ty * w + ret->tx && ret->completed < 0)
ret->completed = ret->movecount;
move += n;
} else {
free_game(ret);
return NULL;
}
if (*move == ';')
move++;
else if (*move) {
free_game(ret);
return NULL;
}
}
return ret;
}
/* ----------------------------------------------------------------------
* Drawing routines.
*/
static void game_compute_size(const game_params *params, int tilesize,
int *x, int *y)
{
/* fool the macros */
struct dummy { int tilesize; } dummy, *ds = &dummy;
dummy.tilesize = tilesize;
*x = params->w * TILESIZE + 2*BORDER;
*y = params->h * TILESIZE + 2*BORDER;
}
static void game_set_size(drawing *dr, game_drawstate *ds,
const game_params *params, int tilesize)
{
ds->tilesize = tilesize;
}
static void raise_colour(float *target, float *src, float *limit)
{
int i;
for (i = 0; i < 3; i++)
target[i] = (2*src[i] + limit[i]) / 3;
}
static float *game_colours(frontend *fe, int *ncolours)
{
float *ret = snewn(3 * NCOLOURS, float);
game_mkhighlight(fe, ret, COL_BACKGROUND, COL_HIGHLIGHT, COL_LOWLIGHT);
/*
* When dragging a tile, we light it up a bit.
*/
raise_colour(ret+3*COL_DRAGGING,
ret+3*COL_BACKGROUND, ret+3*COL_HIGHLIGHT);
raise_colour(ret+3*COL_DRAGGING_HIGHLIGHT,
ret+3*COL_HIGHLIGHT, ret+3*COL_HIGHLIGHT);
raise_colour(ret+3*COL_DRAGGING_LOWLIGHT,
ret+3*COL_LOWLIGHT, ret+3*COL_HIGHLIGHT);
/*
* The main tile is tinted blue.
*/
ret[COL_MAIN * 3 + 0] = ret[COL_BACKGROUND * 3 + 0];
ret[COL_MAIN * 3 + 1] = ret[COL_BACKGROUND * 3 + 1];
ret[COL_MAIN * 3 + 2] = ret[COL_HIGHLIGHT * 3 + 2];
game_mkhighlight_specific(fe, ret, COL_MAIN,
COL_MAIN_HIGHLIGHT, COL_MAIN_LOWLIGHT);
/*
* And we light that up a bit too when dragging.
*/
raise_colour(ret+3*COL_MAIN_DRAGGING,
ret+3*COL_MAIN, ret+3*COL_MAIN_HIGHLIGHT);
raise_colour(ret+3*COL_MAIN_DRAGGING_HIGHLIGHT,
ret+3*COL_MAIN_HIGHLIGHT, ret+3*COL_MAIN_HIGHLIGHT);
raise_colour(ret+3*COL_MAIN_DRAGGING_LOWLIGHT,
ret+3*COL_MAIN_LOWLIGHT, ret+3*COL_MAIN_HIGHLIGHT);
/*
* The target area on the floor is tinted green.
*/
ret[COL_TARGET * 3 + 0] = ret[COL_BACKGROUND * 3 + 0];
ret[COL_TARGET * 3 + 1] = ret[COL_HIGHLIGHT * 3 + 1];
ret[COL_TARGET * 3 + 2] = ret[COL_BACKGROUND * 3 + 2];
game_mkhighlight_specific(fe, ret, COL_TARGET,
COL_TARGET_HIGHLIGHT, COL_TARGET_LOWLIGHT);
*ncolours = NCOLOURS;
return ret;
}
static game_drawstate *game_new_drawstate(drawing *dr, const game_state *state)
{
int w = state->w, h = state->h, wh = w*h;
struct game_drawstate *ds = snew(struct game_drawstate);
int i;
ds->tilesize = 0;
ds->w = w;
ds->h = h;
ds->grid = snewn(wh, unsigned long);
for (i = 0; i < wh; i++)
ds->grid[i] = ~(unsigned long)0;
return ds;
}
static void game_free_drawstate(drawing *dr, game_drawstate *ds)
{
sfree(ds->grid);
sfree(ds);
}
#define BG_NORMAL 0x00000001UL
#define BG_TARGET 0x00000002UL
#define BG_FORCEFIELD 0x00000004UL
#define FLASH_LOW 0x00000008UL
#define FLASH_HIGH 0x00000010UL
#define FG_WALL 0x00000020UL
#define FG_MAIN 0x00000040UL
#define FG_NORMAL 0x00000080UL
#define FG_DRAGGING 0x00000100UL
#define FG_SHADOW 0x00000200UL
#define FG_SOLVEPIECE 0x00000400UL
#define FG_MAINPIECESH 11
#define FG_SHADOWSH 19
#define PIECE_LBORDER 0x00000001UL
#define PIECE_TBORDER 0x00000002UL
#define PIECE_RBORDER 0x00000004UL
#define PIECE_BBORDER 0x00000008UL
#define PIECE_TLCORNER 0x00000010UL
#define PIECE_TRCORNER 0x00000020UL
#define PIECE_BLCORNER 0x00000040UL
#define PIECE_BRCORNER 0x00000080UL
#define PIECE_MASK 0x000000FFUL
/*
* Utility function.
*/
#define TYPE_MASK 0xF000
#define COL_MASK 0x0FFF
#define TYPE_RECT 0x0000
#define TYPE_TLCIRC 0x4000
#define TYPE_TRCIRC 0x5000
#define TYPE_BLCIRC 0x6000
#define TYPE_BRCIRC 0x7000
static void maybe_rect(drawing *dr, int x, int y, int w, int h,
int coltype, int col2)
{
int colour = coltype & COL_MASK, type = coltype & TYPE_MASK;
if (colour > NCOLOURS)
return;
if (type == TYPE_RECT) {
draw_rect(dr, x, y, w, h, colour);
} else {
int cx, cy, r;
clip(dr, x, y, w, h);
cx = x;
cy = y;
r = w-1;
if (type & 0x1000)
cx += r;
if (type & 0x2000)
cy += r;
if (col2 == -1 || col2 == coltype) {
assert(w == h);
draw_circle(dr, cx, cy, r, colour, colour);
} else {
/*
* We aim to draw a quadrant of a circle in two
* different colours. We do this using Bresenham's
* algorithm directly, because the Puzzles drawing API
* doesn't have a draw-sector primitive.
*/
int bx, by, bd, bd2;
int xm = (type & 0x1000 ? -1 : +1);
int ym = (type & 0x2000 ? -1 : +1);
by = r;
bx = 0;
bd = 0;
while (by >= bx) {
/*
* Plot the point.
*/
{
int x1 = cx+xm*bx, y1 = cy+ym*bx;
int x2, y2;
x2 = cx+xm*by; y2 = y1;
draw_rect(dr, min(x1,x2), min(y1,y2),
abs(x1-x2)+1, abs(y1-y2)+1, colour);
x2 = x1; y2 = cy+ym*by;
draw_rect(dr, min(x1,x2), min(y1,y2),
abs(x1-x2)+1, abs(y1-y2)+1, col2);
}
bd += 2*bx + 1;
bd2 = bd - (2*by - 1);
if (abs(bd2) < abs(bd)) {
bd = bd2;
by--;
}
bx++;
}
}
unclip(dr);
}
}
static void draw_wallpart(drawing *dr, game_drawstate *ds,
int tx, int ty, unsigned long val,
int cl, int cc, int ch)
{
int coords[6];
draw_rect(dr, tx, ty, TILESIZE, TILESIZE, cc);
if (val & PIECE_LBORDER)
draw_rect(dr, tx, ty, HIGHLIGHT_WIDTH, TILESIZE,
ch);
if (val & PIECE_RBORDER)
draw_rect(dr, tx+TILESIZE-HIGHLIGHT_WIDTH, ty,
HIGHLIGHT_WIDTH, TILESIZE, cl);
if (val & PIECE_TBORDER)
draw_rect(dr, tx, ty, TILESIZE, HIGHLIGHT_WIDTH, ch);
if (val & PIECE_BBORDER)
draw_rect(dr, tx, ty+TILESIZE-HIGHLIGHT_WIDTH,
TILESIZE, HIGHLIGHT_WIDTH, cl);
if (!((PIECE_BBORDER | PIECE_LBORDER) &~ val)) {
draw_rect(dr, tx, ty+TILESIZE-HIGHLIGHT_WIDTH,
HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH, cl);
clip(dr, tx, ty+TILESIZE-HIGHLIGHT_WIDTH,
HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH);
coords[0] = tx - 1;
coords[1] = ty + TILESIZE - HIGHLIGHT_WIDTH - 1;
coords[2] = tx + HIGHLIGHT_WIDTH;
coords[3] = ty + TILESIZE - HIGHLIGHT_WIDTH - 1;
coords[4] = tx - 1;
coords[5] = ty + TILESIZE;
draw_polygon(dr, coords, 3, ch, ch);
unclip(dr);
} else if (val & PIECE_BLCORNER) {
draw_rect(dr, tx, ty+TILESIZE-HIGHLIGHT_WIDTH,
HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH, ch);
clip(dr, tx, ty+TILESIZE-HIGHLIGHT_WIDTH,
HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH);
coords[0] = tx - 1;
coords[1] = ty + TILESIZE - HIGHLIGHT_WIDTH - 1;
coords[2] = tx + HIGHLIGHT_WIDTH;
coords[3] = ty + TILESIZE - HIGHLIGHT_WIDTH - 1;
coords[4] = tx - 1;
coords[5] = ty + TILESIZE;
draw_polygon(dr, coords, 3, cl, cl);
unclip(dr);
}
if (!((PIECE_TBORDER | PIECE_RBORDER) &~ val)) {
draw_rect(dr, tx+TILESIZE-HIGHLIGHT_WIDTH, ty,
HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH, cl);
clip(dr, tx+TILESIZE-HIGHLIGHT_WIDTH, ty,
HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH);
coords[0] = tx + TILESIZE - HIGHLIGHT_WIDTH - 1;
coords[1] = ty - 1;
coords[2] = tx + TILESIZE;
coords[3] = ty - 1;
coords[4] = tx + TILESIZE - HIGHLIGHT_WIDTH - 1;
coords[5] = ty + HIGHLIGHT_WIDTH;
draw_polygon(dr, coords, 3, ch, ch);
unclip(dr);
} else if (val & PIECE_TRCORNER) {
draw_rect(dr, tx+TILESIZE-HIGHLIGHT_WIDTH, ty,
HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH, ch);
clip(dr, tx+TILESIZE-HIGHLIGHT_WIDTH, ty,
HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH);
coords[0] = tx + TILESIZE - HIGHLIGHT_WIDTH - 1;
coords[1] = ty - 1;
coords[2] = tx + TILESIZE;
coords[3] = ty - 1;
coords[4] = tx + TILESIZE - HIGHLIGHT_WIDTH - 1;
coords[5] = ty + HIGHLIGHT_WIDTH;
draw_polygon(dr, coords, 3, cl, cl);
unclip(dr);
}
if (val & PIECE_TLCORNER)
draw_rect(dr, tx, ty, HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH, ch);
if (val & PIECE_BRCORNER)
draw_rect(dr, tx+TILESIZE-HIGHLIGHT_WIDTH,
ty+TILESIZE-HIGHLIGHT_WIDTH,
HIGHLIGHT_WIDTH, HIGHLIGHT_WIDTH, cl);
}
static void draw_piecepart(drawing *dr, game_drawstate *ds,
int tx, int ty, unsigned long val,
int cl, int cc, int ch)
{
int x[6], y[6];
/*
* Drawing the blocks is hellishly fiddly. The blocks don't
* stretch to the full size of the tile; there's a border
* around them of size BORDER_WIDTH. Then they have bevelled
* borders of size HIGHLIGHT_WIDTH, and also rounded corners.
*
* I tried for some time to find a clean and clever way to
* figure out what needed drawing from the corner and border
* flags, but in the end the cleanest way I could find was the
* following. We divide the grid square into 25 parts by
* ruling four horizontal and four vertical lines across it;
* those lines are at BORDER_WIDTH and BORDER_WIDTH +
* HIGHLIGHT_WIDTH from the top, from the bottom, from the
* left and from the right. Then we carefully consider each of
* the resulting 25 sections of square, and decide separately
* what needs to go in it based on the flags. In complicated
* cases there can be up to five possibilities affecting any
* given section (no corner or border flags, just the corner
* flag, one border flag, the other border flag, both border
* flags). So there's a lot of very fiddly logic here and all
* I could really think to do was give it my best shot and
* then test it and correct all the typos. Not fun to write,
* and I'm sure it isn't fun to read either, but it seems to
* work.
*/
x[0] = tx;
x[1] = x[0] + BORDER_WIDTH;
x[2] = x[1] + HIGHLIGHT_WIDTH;
x[5] = tx + TILESIZE;
x[4] = x[5] - BORDER_WIDTH;
x[3] = x[4] - HIGHLIGHT_WIDTH;
y[0] = ty;
y[1] = y[0] + BORDER_WIDTH;
y[2] = y[1] + HIGHLIGHT_WIDTH;
y[5] = ty + TILESIZE;
y[4] = y[5] - BORDER_WIDTH;
y[3] = y[4] - HIGHLIGHT_WIDTH;
#define RECT(p,q) x[p], y[q], x[(p)+1]-x[p], y[(q)+1]-y[q]
maybe_rect(dr, RECT(0,0),
(val & (PIECE_TLCORNER | PIECE_TBORDER |
PIECE_LBORDER)) ? -1 : cc, -1);
maybe_rect(dr, RECT(1,0),
(val & PIECE_TLCORNER) ? ch : (val & PIECE_TBORDER) ? -1 :
(val & PIECE_LBORDER) ? ch : cc, -1);
maybe_rect(dr, RECT(2,0),
(val & PIECE_TBORDER) ? -1 : cc, -1);
maybe_rect(dr, RECT(3,0),
(val & PIECE_TRCORNER) ? cl : (val & PIECE_TBORDER) ? -1 :
(val & PIECE_RBORDER) ? cl : cc, -1);
maybe_rect(dr, RECT(4,0),
(val & (PIECE_TRCORNER | PIECE_TBORDER |
PIECE_RBORDER)) ? -1 : cc, -1);
maybe_rect(dr, RECT(0,1),
(val & PIECE_TLCORNER) ? ch : (val & PIECE_LBORDER) ? -1 :
(val & PIECE_TBORDER) ? ch : cc, -1);
maybe_rect(dr, RECT(1,1),
(val & PIECE_TLCORNER) ? cc : -1, -1);
maybe_rect(dr, RECT(1,1),
(val & PIECE_TLCORNER) ? ch | TYPE_TLCIRC :
!((PIECE_TBORDER | PIECE_LBORDER) &~ val) ? ch | TYPE_BRCIRC :
(val & (PIECE_TBORDER | PIECE_LBORDER)) ? ch : cc, -1);
maybe_rect(dr, RECT(2,1),
(val & PIECE_TBORDER) ? ch : cc, -1);
maybe_rect(dr, RECT(3,1),
(val & PIECE_TRCORNER) ? cc : -1, -1);
maybe_rect(dr, RECT(3,1),
(val & (PIECE_TBORDER | PIECE_RBORDER)) == PIECE_TBORDER ? ch :
(val & (PIECE_TBORDER | PIECE_RBORDER)) == PIECE_RBORDER ? cl :
!((PIECE_TBORDER|PIECE_RBORDER) &~ val) ? cl | TYPE_BLCIRC :
(val & PIECE_TRCORNER) ? cl | TYPE_TRCIRC :
cc, ch);
maybe_rect(dr, RECT(4,1),
(val & PIECE_TRCORNER) ? ch : (val & PIECE_RBORDER) ? -1 :
(val & PIECE_TBORDER) ? ch : cc, -1);
maybe_rect(dr, RECT(0,2),
(val & PIECE_LBORDER) ? -1 : cc, -1);
maybe_rect(dr, RECT(1,2),
(val & PIECE_LBORDER) ? ch : cc, -1);
maybe_rect(dr, RECT(2,2),
cc, -1);
maybe_rect(dr, RECT(3,2),
(val & PIECE_RBORDER) ? cl : cc, -1);
maybe_rect(dr, RECT(4,2),
(val & PIECE_RBORDER) ? -1 : cc, -1);
maybe_rect(dr, RECT(0,3),
(val & PIECE_BLCORNER) ? cl : (val & PIECE_LBORDER) ? -1 :
(val & PIECE_BBORDER) ? cl : cc, -1);
maybe_rect(dr, RECT(1,3),
(val & PIECE_BLCORNER) ? cc : -1, -1);
maybe_rect(dr, RECT(1,3),
(val & (PIECE_BBORDER | PIECE_LBORDER)) == PIECE_BBORDER ? cl :
(val & (PIECE_BBORDER | PIECE_LBORDER)) == PIECE_LBORDER ? ch :
!((PIECE_BBORDER|PIECE_LBORDER) &~ val) ? ch | TYPE_TRCIRC :
(val & PIECE_BLCORNER) ? ch | TYPE_BLCIRC :
cc, cl);
maybe_rect(dr, RECT(2,3),
(val & PIECE_BBORDER) ? cl : cc, -1);
maybe_rect(dr, RECT(3,3),
(val & PIECE_BRCORNER) ? cc : -1, -1);
maybe_rect(dr, RECT(3,3),
(val & PIECE_BRCORNER) ? cl | TYPE_BRCIRC :
!((PIECE_BBORDER | PIECE_RBORDER) &~ val) ? cl | TYPE_TLCIRC :
(val & (PIECE_BBORDER | PIECE_RBORDER)) ? cl : cc, -1);
maybe_rect(dr, RECT(4,3),
(val & PIECE_BRCORNER) ? cl : (val & PIECE_RBORDER) ? -1 :
(val & PIECE_BBORDER) ? cl : cc, -1);
maybe_rect(dr, RECT(0,4),
(val & (PIECE_BLCORNER | PIECE_BBORDER |
PIECE_LBORDER)) ? -1 : cc, -1);
maybe_rect(dr, RECT(1,4),
(val & PIECE_BLCORNER) ? ch : (val & PIECE_BBORDER) ? -1 :
(val & PIECE_LBORDER) ? ch : cc, -1);
maybe_rect(dr, RECT(2,4),
(val & PIECE_BBORDER) ? -1 : cc, -1);
maybe_rect(dr, RECT(3,4),
(val & PIECE_BRCORNER) ? cl : (val & PIECE_BBORDER) ? -1 :
(val & PIECE_RBORDER) ? cl : cc, -1);
maybe_rect(dr, RECT(4,4),
(val & (PIECE_BRCORNER | PIECE_BBORDER |
PIECE_RBORDER)) ? -1 : cc, -1);
#undef RECT
}
static void draw_tile(drawing *dr, game_drawstate *ds,
int x, int y, unsigned long val)
{
int tx = COORD(x), ty = COORD(y);
int cc, ch, cl;
/*
* Draw the tile background.
*/
if (val & BG_TARGET)
cc = COL_TARGET;
else
cc = COL_BACKGROUND;
ch = cc+1;
cl = cc+2;
if (val & FLASH_LOW)
cc = cl;
else if (val & FLASH_HIGH)
cc = ch;
draw_rect(dr, tx, ty, TILESIZE, TILESIZE, cc);
if (val & BG_FORCEFIELD) {
/*
* Cattle-grid effect to indicate that nothing but the
* main block can slide over this square.
*/
int n = 3 * (TILESIZE / (3*HIGHLIGHT_WIDTH));
int i;
for (i = 1; i < n; i += 3) {
draw_rect(dr, tx,ty+(TILESIZE*i/n), TILESIZE,HIGHLIGHT_WIDTH, cl);
draw_rect(dr, tx+(TILESIZE*i/n),ty, HIGHLIGHT_WIDTH,TILESIZE, cl);
}
}
/*
* Draw the tile midground: a shadow of a block, for
* displaying partial solutions.
*/
if (val & FG_SHADOW) {
draw_piecepart(dr, ds, tx, ty, (val >> FG_SHADOWSH) & PIECE_MASK,
cl, cl, cl);
}
/*
* Draw the tile foreground, i.e. some section of a block or
* wall.
*/
if (val & FG_WALL) {
cc = COL_BACKGROUND;
ch = cc+1;
cl = cc+2;
if (val & FLASH_LOW)
cc = cl;
else if (val & FLASH_HIGH)
cc = ch;
draw_wallpart(dr, ds, tx, ty, (val >> FG_MAINPIECESH) & PIECE_MASK,
cl, cc, ch);
} else if (val & (FG_MAIN | FG_NORMAL)) {
if (val & FG_DRAGGING)
cc = (val & FG_MAIN ? COL_MAIN_DRAGGING : COL_DRAGGING);
else
cc = (val & FG_MAIN ? COL_MAIN : COL_BACKGROUND);
ch = cc+1;
cl = cc+2;
if (val & FLASH_LOW)
cc = cl;
else if (val & (FLASH_HIGH | FG_SOLVEPIECE))
cc = ch;
draw_piecepart(dr, ds, tx, ty, (val >> FG_MAINPIECESH) & PIECE_MASK,
cl, cc, ch);
}
draw_update(dr, tx, ty, TILESIZE, TILESIZE);
}
static unsigned long find_piecepart(int w, int h, int *dsf, int x, int y)
{
int i = y*w+x;
int canon = dsf_canonify(dsf, i);
unsigned long val = 0;
if (x == 0 || canon != dsf_canonify(dsf, i-1))
val |= PIECE_LBORDER;
if (y== 0 || canon != dsf_canonify(dsf, i-w))
val |= PIECE_TBORDER;
if (x == w-1 || canon != dsf_canonify(dsf, i+1))
val |= PIECE_RBORDER;
if (y == h-1 || canon != dsf_canonify(dsf, i+w))
val |= PIECE_BBORDER;
if (!(val & (PIECE_TBORDER | PIECE_LBORDER)) &&
canon != dsf_canonify(dsf, i-1-w))
val |= PIECE_TLCORNER;
if (!(val & (PIECE_TBORDER | PIECE_RBORDER)) &&
canon != dsf_canonify(dsf, i+1-w))
val |= PIECE_TRCORNER;
if (!(val & (PIECE_BBORDER | PIECE_LBORDER)) &&
canon != dsf_canonify(dsf, i-1+w))
val |= PIECE_BLCORNER;
if (!(val & (PIECE_BBORDER | PIECE_RBORDER)) &&
canon != dsf_canonify(dsf, i+1+w))
val |= PIECE_BRCORNER;
return val;
}
static void game_redraw(drawing *dr, game_drawstate *ds,
const game_state *oldstate, const game_state *state,
int dir, const game_ui *ui,
float animtime, float flashtime)
{
int w = state->w, h = state->h, wh = w*h;
unsigned char *board;
int *dsf;
int x, y, mainanchor, mainpos, dragpos, solvepos, solvesrc, solvedst;
/*
* Construct the board we'll be displaying (which may be
* different from the one in state if ui describes a drag in
* progress).
*/
board = snewn(wh, unsigned char);
memcpy(board, state->board, wh);
if (ui->dragging) {
bool mpret = move_piece(w, h, state->board, board,
state->imm->forcefield,
ui->drag_anchor, ui->drag_currpos);
assert(mpret);
}
if (state->soln) {
solvesrc = state->soln->moves[state->soln_index*2];
solvedst = state->soln->moves[state->soln_index*2+1];
if (solvesrc == state->lastmoved_pos)
solvesrc = state->lastmoved;
if (solvesrc == ui->drag_anchor)
solvesrc = ui->drag_currpos;
} else
solvesrc = solvedst = -1;
/*
* Build a dsf out of that board, so we can conveniently tell
* which edges are connected and which aren't.
*/
dsf = snew_dsf(wh);
mainanchor = -1;
for (y = 0; y < h; y++)
for (x = 0; x < w; x++) {
int i = y*w+x;
if (ISDIST(board[i]))
dsf_merge(dsf, i, i - board[i]);
if (board[i] == MAINANCHOR)
mainanchor = i;
if (board[i] == WALL) {
if (x > 0 && board[i-1] == WALL)
dsf_merge(dsf, i, i-1);
if (y > 0 && board[i-w] == WALL)
dsf_merge(dsf, i, i-w);
}
}
assert(mainanchor >= 0);
mainpos = dsf_canonify(dsf, mainanchor);
dragpos = ui->drag_currpos > 0 ? dsf_canonify(dsf, ui->drag_currpos) : -1;
solvepos = solvesrc >= 0 ? dsf_canonify(dsf, solvesrc) : -1;
/*
* Now we can construct the data about what we want to draw.
*/
for (y = 0; y < h; y++)
for (x = 0; x < w; x++) {
int i = y*w+x;
int j;
unsigned long val;
int canon;
/*
* See if this square is part of the target area.
*/
j = i + mainanchor - (state->ty * w + state->tx);
while (j >= 0 && j < wh && ISDIST(board[j]))
j -= board[j];
if (j == mainanchor)
val = BG_TARGET;
else
val = BG_NORMAL;
if (state->imm->forcefield[i])
val |= BG_FORCEFIELD;
if (flashtime > 0) {
int flashtype = (int)(flashtime / FLASH_INTERVAL) & 1;
val |= (flashtype ? FLASH_LOW : FLASH_HIGH);
}
if (board[i] != EMPTY) {
canon = dsf_canonify(dsf, i);
if (board[i] == WALL)
val |= FG_WALL;
else if (canon == mainpos)
val |= FG_MAIN;
else
val |= FG_NORMAL;
if (canon == dragpos)
val |= FG_DRAGGING;
if (canon == solvepos)
val |= FG_SOLVEPIECE;
/*
* Now look around to see if other squares
* belonging to the same block are adjacent to us.
*/
val |= find_piecepart(w, h, dsf, x, y) << FG_MAINPIECESH;
}
/*
* If we're in the middle of showing a solution,
* display a shadow piece for the target of the
* current move.
*/
if (solvepos >= 0) {
int si = i - solvedst + solvesrc;
if (si >= 0 && si < wh && dsf_canonify(dsf, si) == solvepos) {
val |= find_piecepart(w, h, dsf,
si % w, si / w) << FG_SHADOWSH;
val |= FG_SHADOW;
}
}
if (val != ds->grid[i]) {
draw_tile(dr, ds, x, y, val);
ds->grid[i] = val;
}
}
/*
* Update the status bar.
*/
{
char statusbuf[256];
sprintf(statusbuf, "%sMoves: %d",
(state->completed >= 0 ?
(state->cheated ? "Auto-solved. " : "COMPLETED! ") :
(state->cheated ? "Auto-solver used. " : "")),
(state->completed >= 0 ? state->completed : state->movecount));
if (state->minmoves >= 0)
sprintf(statusbuf+strlen(statusbuf), " (min %d)",
state->minmoves);
status_bar(dr, statusbuf);
}
sfree(dsf);
sfree(board);
}
static float game_anim_length(const game_state *oldstate,
const game_state *newstate, int dir, game_ui *ui)
{
return 0.0F;
}
static float game_flash_length(const game_state *oldstate,
const game_state *newstate, int dir, game_ui *ui)
{
if (oldstate->completed < 0 && newstate->completed >= 0)
return FLASH_TIME;
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)
{
}
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)
{
}
static void game_print(drawing *dr, const game_state *state, int tilesize)
{
}
#ifdef COMBINED
#define thegame slide
#endif
const struct game thegame = {
"Slide", NULL, NULL,
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,
true, game_can_format_as_text_now, game_text_format,
new_ui,
free_ui,
encode_ui,
decode_ui,
NULL, /* game_request_keys */
game_changed_state,
NULL, /* current_key_label */
interpret_move,
execute_move,
PREFERRED_TILESIZE, 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,
false, false, game_print_size, game_print,
true, /* wants_statusbar */
false, game_timing_state,
0, /* flags */
};
#ifdef STANDALONE_SOLVER
#include <stdarg.h>
int main(int argc, char **argv)
{
game_params *p;
game_state *s;
char *id = NULL, *desc;
const char *err;
bool count = false;
int ret;
int *moves;
while (--argc > 0) {
char *p = *++argv;
/*
if (!strcmp(p, "-v")) {
verbose = true;
} else
*/
if (!strcmp(p, "-c")) {
count = true;
} else if (*p == '-') {
fprintf(stderr, "%s: unrecognised option `%s'\n", argv[0], p);
return 1;
} else {
id = p;
}
}
if (!id) {
fprintf(stderr, "usage: %s [-c | -v] <game_id>\n", argv[0]);
return 1;
}
desc = strchr(id, ':');
if (!desc) {
fprintf(stderr, "%s: game id expects a colon in it\n", argv[0]);
return 1;
}
*desc++ = '\0';
p = default_params();
decode_params(p, id);
err = validate_desc(p, desc);
if (err) {
fprintf(stderr, "%s: %s\n", argv[0], err);
return 1;
}
s = new_game(NULL, p, desc);
ret = solve_board(s->w, s->h, s->board, s->imm->forcefield,
s->tx, s->ty, -1, &moves);
if (ret < 0) {
printf("No solution found\n");
} else {
int index = 0;
if (count) {
printf("%d moves required\n", ret);
return 0;
}
while (1) {
bool moveret;
char *text = board_text_format(s->w, s->h, s->board,
s->imm->forcefield);
game_state *s2;
printf("position %d:\n%s", index, text);
if (index >= ret)
break;
s2 = dup_game(s);
moveret = move_piece(s->w, s->h, s->board,
s2->board, s->imm->forcefield,
moves[index*2], moves[index*2+1]);
assert(moveret);
free_game(s);
s = s2;
index++;
}
}
return 0;
}
#endif