ref: 0cfaa8fbd77ea39a6752e5df66dc6559a52585e4
dir: /unfinished/sokoban.c/
/*
* sokoban.c: An implementation of the well-known Sokoban barrel-
* pushing game. Random generation is too simplistic to be
* credible, but the rest of the gameplay works well enough to use
* it with hand-written level descriptions.
*/
/*
* TODO:
*
* - I think it would be better to ditch the `prev' array, and
* instead make the `dist' array strictly monotonic (by having
* each distance be something like I*A+S, where A is the grid
* area, I the number of INITIAL squares trampled on, and S the
* number of harmless spaces moved through). This would permit
* the path-tracing when a pull is actually made to choose
* randomly from all the possible shortest routes, which would
* be superior in terms of eliminating directional bias.
* + So when tracing the path back to the current px,py, we
* look at all four adjacent squares, find the minimum
* distance, check that it's _strictly smaller_ than that of
* the current square, and restrict our choice to precisely
* those squares with that minimum distance.
* + The other place `prev' is currently used is in the check
* for consistency of a pull. We would have to replace the
* check for whether prev[ny*w+nx]==oy*w+ox with a check that
* made sure there was at least one adjacent square with a
* smaller distance which _wasn't_ oy*w+ox. Then when we did
* the path-tracing we'd also have to take this special case
* into account.
*
* - More discriminating choice of pull. (Snigger.)
* + favour putting targets in clumps
* + try to shoot for a reasonably consistent number of barrels
* (adjust willingness to generate a new barrel depending on
* how many are already present)
* + adjust willingness to break new ground depending on how
* much is already broken
*
* - generation time parameters:
* + enable NetHack mode (and find a better place for the hole)
* + decide how many of the remaining Is should be walls
*
* - at the end of generation, randomly position the starting
* player coordinates, probably by (somehow) reusing the same
* bfs currently inside the loop.
*
* - possible backtracking?
*
* - IWBNI we could spot completely unreachable bits of level at
* the outside, and not bother drawing grid lines for them. The
* NH levels currently look a bit weird with grid lines on the
* outside of the boundary.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <ctype.h>
#ifdef NO_TGMATH_H
# include <math.h>
#else
# include <tgmath.h>
#endif
#include "puzzles.h"
/*
* Various subsets of these constants are used during game
* generation, game play, game IDs and the game_drawstate.
*/
#define INITIAL 'i' /* used only in game generation */
#define SPACE 's'
#define WALL 'w'
#define PIT 'p'
#define DEEP_PIT 'd'
#define TARGET 't'
#define BARREL 'b'
#define BARRELTARGET 'f' /* target is 'f'illed */
#define PLAYER 'u' /* yo'u'; used in game IDs */
#define PLAYERTARGET 'v' /* bad letter: v is to u as t is to s */
#define INVALID '!' /* used in drawstate to force redraw */
/*
* We also support the use of any capital letter as a barrel, which
* will be displayed with that letter as a label. (This facilitates
* people distributing annotated game IDs for particular Sokoban
* levels, so they can accompany them with verbal instructions
* about pushing particular barrels in particular ways.) Therefore,
* to find out whether something is a barrel, we need a test
* function which does a bit more than just comparing to BARREL.
*
* When resting on target squares, capital-letter barrels are
* replaced with their control-character value (A -> ^A).
*/
#define IS_PLAYER(c) ( (c)==PLAYER || (c)==PLAYERTARGET )
#define IS_BARREL(c) ( (c)==BARREL || (c)==BARRELTARGET || \
((c)>='A' && (c)<='Z') || ((c)>=1 && (c)<=26) )
#define IS_ON_TARGET(c) ( (c)==TARGET || (c)==BARRELTARGET || \
(c)==PLAYERTARGET || ((c)>=1 && (c)<=26) )
#define TARGETISE(b) ( (b)==BARREL ? BARRELTARGET : (b)-('A'-1) )
#define DETARGETISE(b) ( (b)==BARRELTARGET ? BARREL : (b)+('A'-1) )
#define BARREL_LABEL(b) ( (b)>='A'&&(b)<='Z' ? (b) : \
(b)>=1 && (b)<=26 ? (b)+('A'-1) : 0 )
#define DX(d) (d == 0 ? -1 : d == 2 ? +1 : 0)
#define DY(d) (d == 1 ? -1 : d == 3 ? +1 : 0)
#define FLASH_LENGTH 0.3F
enum {
COL_BACKGROUND,
COL_TARGET,
COL_PIT,
COL_DEEP_PIT,
COL_BARREL,
COL_PLAYER,
COL_TEXT,
COL_GRID,
COL_OUTLINE,
COL_HIGHLIGHT,
COL_LOWLIGHT,
COL_WALL,
NCOLOURS
};
struct game_params {
int w, h;
/*
* FIXME: a parameter involving degree of filling in?
*/
};
struct game_state {
game_params p;
unsigned char *grid;
int px, py;
bool completed;
};
static game_params *default_params(void)
{
game_params *ret = snew(game_params);
ret->w = 12;
ret->h = 10;
return ret;
}
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 const struct game_params sokoban_presets[] = {
{ 12, 10 },
{ 16, 12 },
{ 20, 16 },
};
static bool game_fetch_preset(int i, char **name, game_params **params)
{
game_params p, *ret;
char *retname;
char namebuf[80];
if (i < 0 || i >= lenof(sokoban_presets))
return false;
p = sokoban_presets[i];
ret = dup_params(&p);
sprintf(namebuf, "%dx%d", ret->w, ret->h);
retname = dupstr(namebuf);
*params = ret;
*name = retname;
return true;
}
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);
}
}
static char *encode_params(const game_params *params, bool full)
{
char data[256];
sprintf(data, "%dx%d", params->w, params->h);
return dupstr(data);
}
static config_item *game_configure(const game_params *params)
{
config_item *ret;
char buf[80];
ret = snewn(3, 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 = NULL;
ret[2].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);
return ret;
}
static const char *validate_params(const game_params *params, bool full)
{
if (params->w < 4 || params->h < 4)
return "Width and height must both be at least 4";
return NULL;
}
/* ----------------------------------------------------------------------
* Game generation mechanism.
*
* To generate a Sokoban level, we begin with a completely blank
* grid and make valid inverse moves. Grid squares can be in a
* number of states. The states are:
*
* - INITIAL: this square has not as yet been touched by any
* inverse move, which essentially means we haven't decided what
* it is yet.
*
* - SPACE: this square is a space.
*
* - TARGET: this square is a space which is also the target for a
* barrel.
*
* - BARREL: this square contains a barrel.
*
* - BARRELTARGET: this square contains a barrel _on_ a target.
*
* - WALL: this square is a wall.
*
* - PLAYER: this square contains the player.
*
* - PLAYERTARGET: this square contains the player on a target.
*
* We begin with every square of the in state INITIAL, apart from a
* solid ring of WALLs around the edge. We randomly position the
* PLAYER somewhere. Thereafter our valid moves are:
*
* - to move the PLAYER in one direction _pulling_ a barrel after
* us. For this to work, we must have SPACE or INITIAL in the
* direction we're moving, and BARREL or BARRELTARGET in the
* direction we're moving away from. We leave SPACE or TARGET
* respectively in the vacated square.
*
* - to create a new barrel by transforming an INITIAL square into
* BARRELTARGET.
*
* - to move the PLAYER freely through SPACE and TARGET squares,
* leaving SPACE or TARGET where it started.
*
* - to move the player through INITIAL squares, carving a tunnel
* of SPACEs as it goes.
*
* We try to avoid destroying INITIAL squares wherever possible (if
* there's a path to where we want to be using only SPACE, then we
* should always use that). At the end of generation, every square
* still in state INITIAL is one which was not required at any
* point during generation, which means we can randomly choose
* whether to make it SPACE or WALL.
*
* It's unclear as yet what the right strategy for wall placement
* should be. Too few WALLs will yield many alternative solutions
* to the puzzle, whereas too many might rule out so many
* possibilities that the intended solution becomes obvious.
*/
static void sokoban_generate(int w, int h, unsigned char *grid, int moves,
bool nethack, random_state *rs)
{
struct pull {
int ox, oy, nx, ny, score;
};
struct pull *pulls;
int *dist, *prev, *heap;
int x, y, px, py, i, j, d, heapsize, npulls;
pulls = snewn(w * h * 4, struct pull);
dist = snewn(w * h, int);
prev = snewn(w * h, int);
heap = snewn(w * h, int);
/*
* Configure the initial grid.
*/
for (y = 0; y < h; y++)
for (x = 0; x < w; x++)
grid[y*w+x] = (x == 0 || y == 0 || x == w-1 || y == h-1 ?
WALL : INITIAL);
if (nethack)
grid[1] = DEEP_PIT;
/*
* Place the player.
*/
i = random_upto(rs, (w-2) * (h-2));
x = 1 + i % (w-2);
y = 1 + i / (w-2);
grid[y*w+x] = SPACE;
px = x;
py = y;
/*
* Now loop around making random inverse Sokoban moves. In this
* loop we aim to make one actual barrel-pull per iteration,
* plus as many free moves as are necessary to get into
* position for that pull.
*/
while (moves-- >= 0) {
/*
* First enumerate all the viable barrel-pulls we can
* possibly make, counting two pulls of the same barrel in
* different directions as different. We also include pulls
* we can perform by creating a new barrel. Each pull is
* marked with the amount of violence it would have to do
* to the grid.
*/
npulls = 0;
for (y = 0; y < h; y++)
for (x = 0; x < w; x++)
for (d = 0; d < 4; d++) {
int dx = DX(d);
int dy = DY(d);
int nx = x + dx, ny = y + dy;
int npx = nx + dx, npy = ny + dy;
int score = 0;
/*
* The candidate move is to put the player at
* (nx,ny), and move him to (npx,npy), pulling
* a barrel at (x,y) to (nx,ny). So first we
* must check that all those squares are within
* the boundaries of the grid. For this it is
* sufficient to check npx,npy.
*/
if (npx < 0 || npx >= w || npy < 0 || npy >= h)
continue;
/*
* (x,y) must either be a barrel, or a square
* which we can convert into a barrel.
*/
switch (grid[y*w+x]) {
case BARREL: case BARRELTARGET:
break;
case INITIAL:
if (nethack)
continue;
score += 10 /* new_barrel_score */;
break;
case DEEP_PIT:
if (!nethack)
continue;
break;
default:
continue;
}
/*
* (nx,ny) must either be a space, or a square
* which we can convert into a space.
*/
switch (grid[ny*w+nx]) {
case SPACE: case TARGET:
break;
case INITIAL:
score += 3 /* new_space_score */;
break;
default:
continue;
}
/*
* (npx,npy) must also either be a space, or a
* square which we can convert into a space.
*/
switch (grid[npy*w+npx]) {
case SPACE: case TARGET:
break;
case INITIAL:
score += 3 /* new_space_score */;
break;
default:
continue;
}
/*
* That's sufficient to tag this as a possible
* pull right now. We still don't know if we
* can reach the required player position, but
* that's a job for the subsequent BFS phase to
* tell us.
*/
pulls[npulls].ox = x;
pulls[npulls].oy = y;
pulls[npulls].nx = nx;
pulls[npulls].ny = ny;
pulls[npulls].score = score;
#ifdef GENERATION_DIAGNOSTICS
printf("found potential pull: (%d,%d)-(%d,%d) cost %d\n",
pulls[npulls].ox, pulls[npulls].oy,
pulls[npulls].nx, pulls[npulls].ny,
pulls[npulls].score);
#endif
npulls++;
}
#ifdef GENERATION_DIAGNOSTICS
printf("found %d potential pulls\n", npulls);
#endif
/*
* If there are no pulls available at all, we give up.
*
* (FIXME: or perhaps backtrack?)
*/
if (npulls == 0)
break;
/*
* Now we do a BFS from our current position, to find all
* the squares we can get the player into.
*
* This BFS is unusually tricky. We want to give a positive
* distance only to squares which we have to carve through
* INITIALs to get to, which means we can't just stick
* every square we reach on the end of our to-do list.
* Instead, we must maintain our list as a proper priority
* queue.
*/
for (i = 0; i < w*h; i++)
dist[i] = prev[i] = -1;
heap[0] = py*w+px;
heapsize = 1;
dist[py*w+px] = 0;
#define PARENT(n) ( ((n)-1)/2 )
#define LCHILD(n) ( 2*(n)+1 )
#define RCHILD(n) ( 2*(n)+2 )
#define SWAP(i,j) do { int swaptmp = (i); (i) = (j); (j) = swaptmp; } while (0)
while (heapsize > 0) {
/*
* Pull the smallest element off the heap: it's at
* position 0. Move the arbitrary element from the very
* end of the heap into position 0.
*/
y = heap[0] / w;
x = heap[0] % w;
heapsize--;
heap[0] = heap[heapsize];
/*
* Now repeatedly move that arbitrary element down the
* heap by swapping it with the more suitable of its
* children.
*/
i = 0;
while (1) {
int lc, rc;
lc = LCHILD(i);
rc = RCHILD(i);
if (lc >= heapsize)
break; /* we've hit bottom */
if (rc >= heapsize) {
/*
* Special case: there is only one child to
* check.
*/
if (dist[heap[i]] > dist[heap[lc]])
SWAP(heap[i], heap[lc]);
/* _Now_ we've hit bottom. */
break;
} else {
/*
* The common case: there are two children and
* we must check them both.
*/
if (dist[heap[i]] > dist[heap[lc]] ||
dist[heap[i]] > dist[heap[rc]]) {
/*
* Pick the more appropriate child to swap with
* (i.e. the one which would want to be the
* parent if one were above the other - as one
* is about to be).
*/
if (dist[heap[lc]] > dist[heap[rc]]) {
SWAP(heap[i], heap[rc]);
i = rc;
} else {
SWAP(heap[i], heap[lc]);
i = lc;
}
} else {
/* This element is in the right place; we're done. */
break;
}
}
}
/*
* OK, that's given us (x,y) for this phase of the
* search. Now try all directions from here.
*/
for (d = 0; d < 4; d++) {
int dx = DX(d);
int dy = DY(d);
int nx = x + dx, ny = y + dy;
if (nx < 0 || nx >= w || ny < 0 || ny >= h)
continue;
if (grid[ny*w+nx] != SPACE && grid[ny*w+nx] != TARGET &&
grid[ny*w+nx] != INITIAL)
continue;
if (dist[ny*w+nx] == -1) {
dist[ny*w+nx] = dist[y*w+x] + (grid[ny*w+nx] == INITIAL);
prev[ny*w+nx] = y*w+x;
/*
* Now insert ny*w+nx at the end of the heap,
* and move it down to its appropriate resting
* place.
*/
i = heapsize;
heap[heapsize++] = ny*w+nx;
/*
* Swap element n with its parent repeatedly to
* preserve the heap property.
*/
while (i > 0) {
int p = PARENT(i);
if (dist[heap[p]] > dist[heap[i]]) {
SWAP(heap[p], heap[i]);
i = p;
} else
break;
}
}
}
}
#undef PARENT
#undef LCHILD
#undef RCHILD
#undef SWAP
#ifdef GENERATION_DIAGNOSTICS
printf("distance map:\n");
for (i = 0; i < h; i++) {
for (j = 0; j < w; j++) {
int d = dist[i*w+j];
int c;
if (d < 0)
c = '#';
else if (d >= 36)
c = '!';
else if (d >= 10)
c = 'A' - 10 + d;
else
c = '0' + d;
putchar(c);
}
putchar('\n');
}
#endif
/*
* Now we can go back through the `pulls' array, adjusting
* the score for each pull depending on how hard it is to
* reach its starting point, and also throwing out any
* whose starting points are genuinely unreachable even
* with the possibility of carving through INITIAL squares.
*/
for (i = j = 0; i < npulls; i++) {
#ifdef GENERATION_DIAGNOSTICS
printf("potential pull (%d,%d)-(%d,%d)",
pulls[i].ox, pulls[i].oy,
pulls[i].nx, pulls[i].ny);
#endif
x = pulls[i].nx;
y = pulls[i].ny;
if (dist[y*w+x] < 0) {
#ifdef GENERATION_DIAGNOSTICS
printf(" unreachable\n");
#endif
continue; /* this pull isn't feasible at all */
} else {
/*
* Another nasty special case we have to check is
* whether the initial barrel location (ox,oy) is
* on the path used to reach the square. This can
* occur if that square is in state INITIAL: the
* pull is initially considered valid on the basis
* that the INITIAL can become BARRELTARGET, and
* it's also considered reachable on the basis that
* INITIAL can be turned into SPACE, but it can't
* be both at once.
*
* Fortunately, if (ox,oy) is on the path at all,
* it must be only one space from the end, so this
* is easy to spot and rule out.
*/
if (prev[y*w+x] == pulls[i].oy*w+pulls[i].ox) {
#ifdef GENERATION_DIAGNOSTICS
printf(" goes through itself\n");
#endif
continue; /* this pull isn't feasible at all */
}
pulls[j] = pulls[i]; /* structure copy */
pulls[j].score += dist[y*w+x] * 3 /* new_space_score */;
#ifdef GENERATION_DIAGNOSTICS
printf(" reachable at distance %d (cost now %d)\n",
dist[y*w+x], pulls[j].score);
#endif
j++;
}
}
npulls = j;
/*
* Again, if there are no pulls available at all, we give
* up.
*
* (FIXME: or perhaps backtrack?)
*/
if (npulls == 0)
break;
/*
* Now choose which pull to make. On the one hand we should
* prefer pulls which do less damage to the INITIAL squares
* (thus, ones for which we can already get into position
* via existing SPACEs, and for which the barrel already
* exists and doesn't have to be invented); on the other,
* we want to avoid _always_ preferring such pulls, on the
* grounds that that will lead to levels without very much
* stuff in.
*
* When creating new barrels, we prefer creations which are
* next to existing TARGET squares.
*
* FIXME: for the moment I'll make this very simple indeed.
*/
i = random_upto(rs, npulls);
/*
* Actually make the pull, including carving a path to get
* to the site if necessary.
*/
x = pulls[i].nx;
y = pulls[i].ny;
while (prev[y*w+x] >= 0) {
int p;
if (grid[y*w+x] == INITIAL)
grid[y*w+x] = SPACE;
p = prev[y*w+x];
y = p / w;
x = p % w;
}
px = 2*pulls[i].nx - pulls[i].ox;
py = 2*pulls[i].ny - pulls[i].oy;
if (grid[py*w+px] == INITIAL)
grid[py*w+px] = SPACE;
if (grid[pulls[i].ny*w+pulls[i].nx] == TARGET)
grid[pulls[i].ny*w+pulls[i].nx] = BARRELTARGET;
else
grid[pulls[i].ny*w+pulls[i].nx] = BARREL;
if (grid[pulls[i].oy*w+pulls[i].ox] == BARREL)
grid[pulls[i].oy*w+pulls[i].ox] = SPACE;
else if (grid[pulls[i].oy*w+pulls[i].ox] != DEEP_PIT)
grid[pulls[i].oy*w+pulls[i].ox] = TARGET;
}
sfree(heap);
sfree(prev);
sfree(dist);
sfree(pulls);
if (grid[py*w+px] == TARGET)
grid[py*w+px] = PLAYERTARGET;
else
grid[py*w+px] = PLAYER;
}
static char *new_game_desc(const game_params *params, random_state *rs,
char **aux, bool interactive)
{
int w = params->w, h = params->h;
char *desc;
int desclen, descpos, descsize, prev, count;
unsigned char *grid;
int i, j;
/*
* FIXME: perhaps some more interesting means of choosing how
* many moves to try?
*/
grid = snewn(w*h, unsigned char);
sokoban_generate(w, h, grid, w*h, false, rs);
desclen = descpos = descsize = 0;
desc = NULL;
prev = -1;
count = 0;
for (i = 0; i < w*h; i++) {
if (descsize < desclen + 40) {
descsize = desclen + 100;
desc = sresize(desc, descsize, char);
desc[desclen] = '\0';
}
switch (grid[i]) {
case INITIAL:
j = 'w'; /* FIXME: make some of these 's'? */
break;
case SPACE:
j = 's';
break;
case WALL:
j = 'w';
break;
case TARGET:
j = 't';
break;
case BARREL:
j = 'b';
break;
case BARRELTARGET:
j = 'f';
break;
case DEEP_PIT:
j = 'd';
break;
case PLAYER:
j = 'u';
break;
case PLAYERTARGET:
j = 'v';
break;
default:
j = '?';
break;
}
assert(j != '?');
if (j != prev) {
desc[desclen++] = j;
descpos = desclen;
prev = j;
count = 1;
} else {
count++;
desclen = descpos + sprintf(desc+descpos, "%d", count);
}
}
sfree(grid);
return desc;
}
static const char *validate_desc(const game_params *params, const char *desc)
{
int w = params->w, h = params->h;
int area = 0;
int nplayers = 0;
while (*desc) {
int c = *desc++;
int n = 1;
if (*desc && isdigit((unsigned char)*desc)) {
n = atoi(desc);
while (*desc && isdigit((unsigned char)*desc)) desc++;
}
area += n;
if (c == PLAYER || c == PLAYERTARGET)
nplayers += n;
else if (c == INITIAL || c == SPACE || c == WALL || c == TARGET ||
c == PIT || c == DEEP_PIT || IS_BARREL(c))
/* ok */;
else
return "Invalid character in game description";
}
if (area > w*h)
return "Too much data in game description";
if (area < w*h)
return "Too little data in game description";
if (nplayers < 1)
return "No starting player position specified";
if (nplayers > 1)
return "More than one starting player position specified";
return NULL;
}
static game_state *new_game(midend *me, const game_params *params,
const char *desc)
{
int w = params->w, h = params->h;
game_state *state = snew(game_state);
int i;
state->p = *params; /* structure copy */
state->grid = snewn(w*h, unsigned char);
state->px = state->py = -1;
state->completed = false;
i = 0;
while (*desc) {
int c = *desc++;
int n = 1;
if (*desc && isdigit((unsigned char)*desc)) {
n = atoi(desc);
while (*desc && isdigit((unsigned char)*desc)) desc++;
}
if (c == PLAYER || c == PLAYERTARGET) {
state->py = i / w;
state->px = i % w;
c = IS_ON_TARGET(c) ? TARGET : SPACE;
}
while (n-- > 0)
state->grid[i++] = c;
}
assert(i == w*h);
assert(state->px != -1 && state->py != -1);
return state;
}
static game_state *dup_game(const game_state *state)
{
int w = state->p.w, h = state->p.h;
game_state *ret = snew(game_state);
ret->p = state->p; /* structure copy */
ret->grid = snewn(w*h, unsigned char);
memcpy(ret->grid, state->grid, w*h);
ret->px = state->px;
ret->py = state->py;
ret->completed = state->completed;
return ret;
}
static void free_game(game_state *state)
{
sfree(state->grid);
sfree(state);
}
static char *solve_game(const game_state *state, const game_state *currstate,
const char *aux, const char **error)
{
return NULL;
}
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;
}
static game_ui *new_ui(const game_state *state)
{
return NULL;
}
static void free_ui(game_ui *ui)
{
}
static void game_changed_state(game_ui *ui, const game_state *oldstate,
const game_state *newstate)
{
}
struct game_drawstate {
game_params p;
int tilesize;
bool started;
unsigned short *grid;
};
#define PREFERRED_TILESIZE 32
#define TILESIZE (ds->tilesize)
#define BORDER (TILESIZE)
#define HIGHLIGHT_WIDTH (TILESIZE / 10)
#define COORD(x) ( (x) * TILESIZE + BORDER )
#define FROMCOORD(x) ( ((x) - BORDER + TILESIZE) / TILESIZE - 1 )
/*
* I'm going to need to do most of the move-type analysis in both
* interpret_move and execute_move, so I'll abstract it out into a
* subfunction. move_type() returns -1 for an illegal move, 0 for a
* movement, and 1 for a push.
*/
static int move_type(const game_state *state, int dx, int dy)
{
int w = state->p.w, h = state->p.h;
int px = state->px, py = state->py;
int nx, ny, nbx, nby;
assert(dx >= -1 && dx <= +1);
assert(dy >= -1 && dy <= +1);
assert(dx || dy);
nx = px + dx;
ny = py + dy;
/*
* Disallow any move that goes off the grid.
*/
if (nx < 0 || nx >= w || ny < 0 || ny >= h)
return -1;
/*
* Examine the target square of the move to see whether it's a
* space, a barrel, or a wall.
*/
if (state->grid[ny*w+nx] == WALL ||
state->grid[ny*w+nx] == PIT ||
state->grid[ny*w+nx] == DEEP_PIT)
return -1; /* this one's easy; just disallow it */
if (IS_BARREL(state->grid[ny*w+nx])) {
/*
* This is a push move. For a start, that means it must not
* be diagonal.
*/
if (dy && dx)
return -1;
/*
* Now find the location of the third square involved in
* the push, and stop if it's off the edge.
*/
nbx = nx + dx;
nby = ny + dy;
if (nbx < 0 || nbx >= w || nby < 0 || nby >= h)
return -1;
/*
* That third square must be able to accept a barrel.
*/
if (state->grid[nby*w+nbx] == SPACE ||
state->grid[nby*w+nbx] == TARGET ||
state->grid[nby*w+nbx] == PIT ||
state->grid[nby*w+nbx] == DEEP_PIT) {
/*
* The push is valid.
*/
return 1;
} else {
return -1;
}
} else {
/*
* This is just an ordinary move. We've already checked the
* target square, so the only thing left to check is that a
* diagonal move has a space on one side to have notionally
* gone through.
*/
if (dx && dy &&
state->grid[(py+dy)*w+px] != SPACE &&
state->grid[(py+dy)*w+px] != TARGET &&
state->grid[py*w+(px+dx)] != SPACE &&
state->grid[py*w+(px+dx)] != TARGET)
return -1;
/*
* Otherwise, the move is valid.
*/
return 0;
}
}
static char *interpret_move(const game_state *state, game_ui *ui,
const game_drawstate *ds,
int x, int y, int button)
{
int dx=0, dy=0;
char *move;
/*
* Diagonal movement is supported as it is in NetHack: it's
* for movement only (never pushing), and one of the two
* squares adjacent to both the source and destination
* squares must be free to move through. In other words, it
* is only a shorthand for two orthogonal moves and cannot
* change the nature of the actual puzzle game.
*/
if (button == CURSOR_UP || button == (MOD_NUM_KEYPAD | '8'))
dx = 0, dy = -1;
else if (button == CURSOR_DOWN || button == (MOD_NUM_KEYPAD | '2'))
dx = 0, dy = +1;
else if (button == CURSOR_LEFT || button == (MOD_NUM_KEYPAD | '4'))
dx = -1, dy = 0;
else if (button == CURSOR_RIGHT || button == (MOD_NUM_KEYPAD | '6'))
dx = +1, dy = 0;
else if (button == (MOD_NUM_KEYPAD | '7'))
dx = -1, dy = -1;
else if (button == (MOD_NUM_KEYPAD | '9'))
dx = +1, dy = -1;
else if (button == (MOD_NUM_KEYPAD | '1'))
dx = -1, dy = +1;
else if (button == (MOD_NUM_KEYPAD | '3'))
dx = +1, dy = +1;
else if (button == LEFT_BUTTON)
{
if(x < COORD(state->px))
dx = -1;
else if (x > COORD(state->px + 1))
dx = 1;
if(y < COORD(state->py))
dy = -1;
else if (y > COORD(state->py + 1))
dy = 1;
}
else
return NULL;
if((dx == 0) && (dy == 0))
return(NULL);
if (move_type(state, dx, dy) < 0)
return NULL;
move = snewn(2, char);
move[1] = '\0';
move[0] = '5' - 3*dy + dx;
return move;
}
static game_state *execute_move(const game_state *state, const char *move)
{
int w = state->p.w, h = state->p.h;
int px = state->px, py = state->py;
int dx, dy, nx, ny, nbx, nby, type, m, i;
bool freebarrels, freetargets;
game_state *ret;
if (*move < '1' || *move == '5' || *move > '9' || move[1])
return NULL; /* invalid move string */
m = *move - '0';
dx = (m + 2) % 3 - 1;
dy = 2 - (m + 2) / 3;
type = move_type(state, dx, dy);
if (type < 0)
return NULL;
ret = dup_game(state);
nx = px + dx;
ny = py + dy;
nbx = nx + dx;
nby = ny + dy;
if (type) {
int b;
/*
* Push.
*/
b = ret->grid[ny*w+nx];
if (IS_ON_TARGET(b)) {
ret->grid[ny*w+nx] = TARGET;
b = DETARGETISE(b);
} else
ret->grid[ny*w+nx] = SPACE;
if (ret->grid[nby*w+nbx] == PIT)
ret->grid[nby*w+nbx] = SPACE;
else if (ret->grid[nby*w+nbx] == DEEP_PIT)
/* do nothing - the pit eats the barrel and remains there */;
else if (ret->grid[nby*w+nbx] == TARGET)
ret->grid[nby*w+nbx] = TARGETISE(b);
else
ret->grid[nby*w+nbx] = b;
}
ret->px = nx;
ret->py = ny;
/*
* Check for completion. This is surprisingly complicated,
* given the presence of pits and deep pits, and also the fact
* that some Sokoban levels with pits have fewer pits than
* barrels (due to providing spares, e.g. NetHack's). I think
* the completion condition in fact must be that the game
* cannot become any _more_ complete. That is, _either_ there
* are no remaining barrels not on targets, _or_ there is a
* good reason why any such barrels cannot be placed. The only
* available good reason is that there are no remaining pits,
* no free target squares, and no deep pits at all.
*/
if (!ret->completed) {
freebarrels = false;
freetargets = false;
for (i = 0; i < w*h; i++) {
int v = ret->grid[i];
if (IS_BARREL(v) && !IS_ON_TARGET(v))
freebarrels = true;
if (v == DEEP_PIT || v == PIT ||
(!IS_BARREL(v) && IS_ON_TARGET(v)))
freetargets = true;
}
if (!freebarrels || !freetargets)
ret->completed = true;
}
return ret;
}
/* ----------------------------------------------------------------------
* Drawing routines.
*/
static void game_compute_size(const game_params *params, int tilesize,
const game_ui *ui, int *x, int *y)
{
/* Ick: fake up `ds->tilesize' for macro expansion purposes */
struct { int tilesize; } ads, *ds = &ads;
ads.tilesize = tilesize;
*x = 2 * BORDER + 1 + params->w * TILESIZE;
*y = 2 * BORDER + 1 + params->h * TILESIZE;
}
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 = snewn(3 * NCOLOURS, float);
int i;
game_mkhighlight(fe, ret, COL_BACKGROUND, COL_HIGHLIGHT, COL_LOWLIGHT);
ret[COL_OUTLINE * 3 + 0] = 0.0F;
ret[COL_OUTLINE * 3 + 1] = 0.0F;
ret[COL_OUTLINE * 3 + 2] = 0.0F;
ret[COL_PLAYER * 3 + 0] = 0.0F;
ret[COL_PLAYER * 3 + 1] = 1.0F;
ret[COL_PLAYER * 3 + 2] = 0.0F;
ret[COL_BARREL * 3 + 0] = 0.6F;
ret[COL_BARREL * 3 + 1] = 0.3F;
ret[COL_BARREL * 3 + 2] = 0.0F;
ret[COL_TARGET * 3 + 0] = ret[COL_LOWLIGHT * 3 + 0];
ret[COL_TARGET * 3 + 1] = ret[COL_LOWLIGHT * 3 + 1];
ret[COL_TARGET * 3 + 2] = ret[COL_LOWLIGHT * 3 + 2];
ret[COL_PIT * 3 + 0] = ret[COL_LOWLIGHT * 3 + 0] / 2;
ret[COL_PIT * 3 + 1] = ret[COL_LOWLIGHT * 3 + 1] / 2;
ret[COL_PIT * 3 + 2] = ret[COL_LOWLIGHT * 3 + 2] / 2;
ret[COL_DEEP_PIT * 3 + 0] = 0.0F;
ret[COL_DEEP_PIT * 3 + 1] = 0.0F;
ret[COL_DEEP_PIT * 3 + 2] = 0.0F;
ret[COL_TEXT * 3 + 0] = 1.0F;
ret[COL_TEXT * 3 + 1] = 1.0F;
ret[COL_TEXT * 3 + 2] = 1.0F;
ret[COL_GRID * 3 + 0] = ret[COL_LOWLIGHT * 3 + 0];
ret[COL_GRID * 3 + 1] = ret[COL_LOWLIGHT * 3 + 1];
ret[COL_GRID * 3 + 2] = ret[COL_LOWLIGHT * 3 + 2];
ret[COL_OUTLINE * 3 + 0] = 0.0F;
ret[COL_OUTLINE * 3 + 1] = 0.0F;
ret[COL_OUTLINE * 3 + 2] = 0.0F;
for (i = 0; i < 3; i++) {
ret[COL_WALL * 3 + i] = (3 * ret[COL_BACKGROUND * 3 + i] +
1 * ret[COL_HIGHLIGHT * 3 + i]) / 4;
}
*ncolours = NCOLOURS;
return ret;
}
static game_drawstate *game_new_drawstate(drawing *dr, const game_state *state)
{
int w = state->p.w, h = state->p.h;
struct game_drawstate *ds = snew(struct game_drawstate);
int i;
ds->tilesize = 0;
ds->p = state->p; /* structure copy */
ds->grid = snewn(w*h, unsigned short);
for (i = 0; i < w*h; i++)
ds->grid[i] = INVALID;
ds->started = false;
return ds;
}
static void game_free_drawstate(drawing *dr, game_drawstate *ds)
{
sfree(ds->grid);
sfree(ds);
}
static void draw_tile(drawing *dr, game_drawstate *ds, int x, int y, int v)
{
int tx = COORD(x), ty = COORD(y);
int bg = (v & 0x100 ? COL_HIGHLIGHT : COL_BACKGROUND);
v &= 0xFF;
clip(dr, tx+1, ty+1, TILESIZE-1, TILESIZE-1);
draw_rect(dr, tx+1, ty+1, TILESIZE-1, TILESIZE-1, bg);
if (v == WALL) {
int coords[6];
coords[0] = tx + TILESIZE;
coords[1] = ty + TILESIZE;
coords[2] = tx + TILESIZE;
coords[3] = ty + 1;
coords[4] = tx + 1;
coords[5] = ty + TILESIZE;
draw_polygon(dr, coords, 3, COL_LOWLIGHT, COL_LOWLIGHT);
coords[0] = tx + 1;
coords[1] = ty + 1;
draw_polygon(dr, coords, 3, COL_HIGHLIGHT, COL_HIGHLIGHT);
draw_rect(dr, tx + 1 + HIGHLIGHT_WIDTH, ty + 1 + HIGHLIGHT_WIDTH,
TILESIZE - 2*HIGHLIGHT_WIDTH,
TILESIZE - 2*HIGHLIGHT_WIDTH, COL_WALL);
} else if (v == PIT) {
draw_circle(dr, tx + TILESIZE/2, ty + TILESIZE/2,
TILESIZE*3/7, COL_PIT, COL_OUTLINE);
} else if (v == DEEP_PIT) {
draw_circle(dr, tx + TILESIZE/2, ty + TILESIZE/2,
TILESIZE*3/7, COL_DEEP_PIT, COL_OUTLINE);
} else {
if (IS_ON_TARGET(v)) {
draw_circle(dr, tx + TILESIZE/2, ty + TILESIZE/2,
TILESIZE*3/7, COL_TARGET, COL_OUTLINE);
}
if (IS_PLAYER(v)) {
draw_circle(dr, tx + TILESIZE/2, ty + TILESIZE/2,
TILESIZE/3, COL_PLAYER, COL_OUTLINE);
} else if (IS_BARREL(v)) {
char str[2];
draw_circle(dr, tx + TILESIZE/2, ty + TILESIZE/2,
TILESIZE/3, COL_BARREL, COL_OUTLINE);
str[1] = '\0';
str[0] = BARREL_LABEL(v);
if (str[0]) {
draw_text(dr, tx + TILESIZE/2, ty + TILESIZE/2,
FONT_VARIABLE, TILESIZE/2,
ALIGN_VCENTRE | ALIGN_HCENTRE, COL_TEXT, str);
}
}
}
unclip(dr);
draw_update(dr, tx, ty, TILESIZE, TILESIZE);
}
static void game_redraw(drawing *dr, game_drawstate *ds,
const game_state *oldstate, const game_state *state,
int dir, const game_ui *ui,
float animtime, float flashtime)
{
int w = state->p.w, h = state->p.h /*, wh = w*h */;
int x, y;
int flashtype;
if (flashtime &&
!((int)(flashtime * 3 / FLASH_LENGTH) % 2))
flashtype = 0x100;
else
flashtype = 0;
/*
* Initialise a fresh drawstate.
*/
if (!ds->started) {
/*
* Draw the grid lines.
*/
for (y = 0; y <= h; y++)
draw_line(dr, COORD(0), COORD(y), COORD(w), COORD(y),
COL_LOWLIGHT);
for (x = 0; x <= w; x++)
draw_line(dr, COORD(x), COORD(0), COORD(x), COORD(h),
COL_LOWLIGHT);
ds->started = true;
}
/*
* Draw the grid contents.
*/
for (y = 0; y < h; y++)
for (x = 0; x < w; x++) {
int v = state->grid[y*w+x];
if (y == state->py && x == state->px) {
if (v == TARGET)
v = PLAYERTARGET;
else {
assert(v == SPACE);
v = PLAYER;
}
}
v |= flashtype;
if (ds->grid[y*w+x] != v) {
draw_tile(dr, ds, x, y, v);
ds->grid[y*w+x] = v;
}
}
}
static float game_anim_length(const game_state *oldstate,
const game_state *newstate, int dir, game_ui *ui)
{
return 0.0F;
}
static float game_flash_length(const game_state *oldstate,
const game_state *newstate, int dir, game_ui *ui)
{
if (!oldstate->completed && newstate->completed)
return FLASH_LENGTH;
else
return 0.0F;
}
static void game_get_cursor_location(const game_ui *ui,
const game_drawstate *ds,
const game_state *state,
const game_params *params,
int *x, int *y, int *w, int *h)
{
}
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, const game_ui *ui,
float *x, float *y)
{
}
static void game_print(drawing *dr, const game_state *state, const game_ui *ui,
int tilesize)
{
}
#ifdef COMBINED
#define thegame sokoban
#endif
const struct game thegame = {
"Sokoban", 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,
false, solve_game,
false, game_can_format_as_text_now, game_text_format,
NULL, NULL, /* get_prefs, set_prefs */
new_ui,
free_ui,
NULL, /* encode_ui */
NULL, /* 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,
false, /* wants_statusbar */
false, game_timing_state,
0, /* flags */
};