ref: 9def49ae9abc6ee7831264827adcd9ef2a5c28e4
dir: /fifteen.c/
/*
* fifteen.c: standard 15-puzzle.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <ctype.h>
#include <math.h>
#include "puzzles.h"
#define PREFERRED_TILE_SIZE 48
#define TILE_SIZE (ds->tilesize)
#define BORDER (TILE_SIZE / 2)
#define HIGHLIGHT_WIDTH (TILE_SIZE / 20)
#define COORD(x) ( (x) * TILE_SIZE + BORDER )
#define FROMCOORD(x) ( ((x) - BORDER + TILE_SIZE) / TILE_SIZE - 1 )
#define ANIM_TIME 0.13F
#define FLASH_FRAME 0.13F
#define X(state, i) ( (i) % (state)->w )
#define Y(state, i) ( (i) / (state)->w )
#define C(state, x, y) ( (y) * (state)->w + (x) )
enum {
COL_BACKGROUND,
COL_TEXT,
COL_HIGHLIGHT,
COL_LOWLIGHT,
NCOLOURS
};
struct game_params {
int w, h;
};
struct game_state {
int w, h, n;
int *tiles;
int gap_pos;
int completed;
int used_solve; /* used to suppress completion flash */
int movecount;
};
static game_params *default_params(void)
{
game_params *ret = snew(game_params);
ret->w = ret->h = 4;
return ret;
}
static int game_fetch_preset(int i, char **name, game_params **params)
{
if (i == 0) {
*params = default_params();
*name = dupstr("4x4");
return TRUE;
}
return FALSE;
}
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)
{
ret->w = ret->h = atoi(string);
while (*string && isdigit((unsigned char)*string)) string++;
if (*string == 'x') {
string++;
ret->h = atoi(string);
}
}
static char *encode_params(const game_params *params, int 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].sval = dupstr(buf);
ret[0].ival = 0;
ret[1].name = "Height";
ret[1].type = C_STRING;
sprintf(buf, "%d", params->h);
ret[1].sval = dupstr(buf);
ret[1].ival = 0;
ret[2].name = NULL;
ret[2].type = C_END;
ret[2].sval = NULL;
ret[2].ival = 0;
return ret;
}
static game_params *custom_params(const config_item *cfg)
{
game_params *ret = snew(game_params);
ret->w = atoi(cfg[0].sval);
ret->h = atoi(cfg[1].sval);
return ret;
}
static char *validate_params(const game_params *params, int full)
{
if (params->w < 2 || params->h < 2)
return "Width and height must both be at least two";
return NULL;
}
static int perm_parity(int *perm, int n)
{
int i, j, ret;
ret = 0;
for (i = 0; i < n-1; i++)
for (j = i+1; j < n; j++)
if (perm[i] > perm[j])
ret = !ret;
return ret;
}
static char *new_game_desc(const game_params *params, random_state *rs,
char **aux, int interactive)
{
int gap, n, i, x;
int x1, x2, p1, p2, parity;
int *tiles, *used;
char *ret;
int retlen;
n = params->w * params->h;
tiles = snewn(n, int);
used = snewn(n, int);
for (i = 0; i < n; i++) {
tiles[i] = -1;
used[i] = FALSE;
}
gap = random_upto(rs, n);
tiles[gap] = 0;
used[0] = TRUE;
/*
* Place everything else except the last two tiles.
*/
for (x = 0, i = n-1; i > 2; i--) {
int k = random_upto(rs, i);
int j;
for (j = 0; j < n; j++)
if (!used[j] && (k-- == 0))
break;
assert(j < n && !used[j]);
used[j] = TRUE;
while (tiles[x] >= 0)
x++;
assert(x < n);
tiles[x] = j;
}
/*
* Find the last two locations, and the last two pieces.
*/
while (tiles[x] >= 0)
x++;
assert(x < n);
x1 = x;
x++;
while (tiles[x] >= 0)
x++;
assert(x < n);
x2 = x;
for (i = 0; i < n; i++)
if (!used[i])
break;
p1 = i;
for (i = p1+1; i < n; i++)
if (!used[i])
break;
p2 = i;
/*
* Determine the required parity of the overall permutation.
* This is the XOR of:
*
* - The chessboard parity ((x^y)&1) of the gap square. The
* bottom right counts as even.
*
* - The parity of n. (The target permutation is 1,...,n-1,0
* rather than 0,...,n-1; this is a cyclic permutation of
* the starting point and hence is odd iff n is even.)
*/
parity = ((X(params, gap) - (params->w-1)) ^
(Y(params, gap) - (params->h-1)) ^
(n+1)) & 1;
/*
* Try the last two tiles one way round. If that fails, swap
* them.
*/
tiles[x1] = p1;
tiles[x2] = p2;
if (perm_parity(tiles, n) != parity) {
tiles[x1] = p2;
tiles[x2] = p1;
assert(perm_parity(tiles, n) == parity);
}
/*
* Now construct the game description, by describing the tile
* array as a simple sequence of comma-separated integers.
*/
ret = NULL;
retlen = 0;
for (i = 0; i < n; i++) {
char buf[80];
int k;
k = sprintf(buf, "%d,", tiles[i]);
ret = sresize(ret, retlen + k + 1, char);
strcpy(ret + retlen, buf);
retlen += k;
}
ret[retlen-1] = '\0'; /* delete last comma */
sfree(tiles);
sfree(used);
return ret;
}
static char *validate_desc(const game_params *params, const char *desc)
{
const char *p;
char *err;
int i, area;
int *used;
area = params->w * params->h;
p = desc;
err = NULL;
used = snewn(area, int);
for (i = 0; i < area; i++)
used[i] = FALSE;
for (i = 0; i < area; i++) {
const char *q = p;
int n;
if (*p < '0' || *p > '9') {
err = "Not enough numbers in string";
goto leave;
}
while (*p >= '0' && *p <= '9')
p++;
if (i < area-1 && *p != ',') {
err = "Expected comma after number";
goto leave;
}
else if (i == area-1 && *p) {
err = "Excess junk at end of string";
goto leave;
}
n = atoi(q);
if (n < 0 || n >= area) {
err = "Number out of range";
goto leave;
}
if (used[n]) {
err = "Number used twice";
goto leave;
}
used[n] = TRUE;
if (*p) p++; /* eat comma */
}
leave:
sfree(used);
return err;
}
static game_state *new_game(midend *me, const game_params *params,
const char *desc)
{
game_state *state = snew(game_state);
int i;
const char *p;
state->w = params->w;
state->h = params->h;
state->n = params->w * params->h;
state->tiles = snewn(state->n, int);
state->gap_pos = 0;
p = desc;
i = 0;
for (i = 0; i < state->n; i++) {
assert(*p);
state->tiles[i] = atoi(p);
if (state->tiles[i] == 0)
state->gap_pos = i;
while (*p && *p != ',')
p++;
if (*p) p++; /* eat comma */
}
assert(!*p);
assert(state->tiles[state->gap_pos] == 0);
state->completed = state->movecount = 0;
state->used_solve = FALSE;
return state;
}
static game_state *dup_game(const game_state *state)
{
game_state *ret = snew(game_state);
ret->w = state->w;
ret->h = state->h;
ret->n = state->n;
ret->tiles = snewn(state->w * state->h, int);
memcpy(ret->tiles, state->tiles, state->w * state->h * sizeof(int));
ret->gap_pos = state->gap_pos;
ret->completed = state->completed;
ret->movecount = state->movecount;
ret->used_solve = state->used_solve;
return ret;
}
static void free_game(game_state *state)
{
sfree(state->tiles);
sfree(state);
}
static char *solve_game(const game_state *state, const game_state *currstate,
const char *aux, char **error)
{
return dupstr("S");
}
static int game_can_format_as_text_now(const game_params *params)
{
return TRUE;
}
static char *game_text_format(const game_state *state)
{
char *ret, *p, buf[80];
int x, y, col, maxlen;
/*
* First work out how many characters we need to display each
* number.
*/
col = sprintf(buf, "%d", state->n-1);
/*
* Now we know the exact total size of the grid we're going to
* produce: it's got h rows, each containing w lots of col, w-1
* spaces and a trailing newline.
*/
maxlen = state->h * state->w * (col+1);
ret = snewn(maxlen+1, char);
p = ret;
for (y = 0; y < state->h; y++) {
for (x = 0; x < state->w; x++) {
int v = state->tiles[state->w*y+x];
if (v == 0)
sprintf(buf, "%*s", col, "");
else
sprintf(buf, "%*d", col, v);
memcpy(p, buf, col);
p += col;
if (x+1 == state->w)
*p++ = '\n';
else
*p++ = ' ';
}
}
assert(p - ret == maxlen);
*p = '\0';
return ret;
}
static game_ui *new_ui(const game_state *state)
{
return NULL;
}
static void free_ui(game_ui *ui)
{
}
static char *encode_ui(const game_ui *ui)
{
return NULL;
}
static void decode_ui(game_ui *ui, const char *encoding)
{
}
static void game_changed_state(game_ui *ui, const game_state *oldstate,
const game_state *newstate)
{
}
struct game_drawstate {
int started;
int w, h, bgcolour;
int *tiles;
int tilesize;
};
static char *interpret_move(const game_state *state, game_ui *ui,
const game_drawstate *ds,
int x, int y, int button)
{
int gx, gy, dx, dy;
char buf[80];
button &= ~MOD_MASK;
gx = X(state, state->gap_pos);
gy = Y(state, state->gap_pos);
if (button == CURSOR_RIGHT && gx > 0)
dx = gx - 1, dy = gy;
else if (button == CURSOR_LEFT && gx < state->w-1)
dx = gx + 1, dy = gy;
else if (button == CURSOR_DOWN && gy > 0)
dy = gy - 1, dx = gx;
else if (button == CURSOR_UP && gy < state->h-1)
dy = gy + 1, dx = gx;
else if (button == LEFT_BUTTON) {
dx = FROMCOORD(x);
dy = FROMCOORD(y);
if (dx < 0 || dx >= state->w || dy < 0 || dy >= state->h)
return NULL; /* out of bounds */
/*
* Any click location should be equal to the gap location
* in _precisely_ one coordinate.
*/
if ((dx == gx && dy == gy) || (dx != gx && dy != gy))
return NULL;
} else
return NULL; /* no move */
sprintf(buf, "M%d,%d", dx, dy);
return dupstr(buf);
}
static game_state *execute_move(const game_state *from, const char *move)
{
int gx, gy, dx, dy, ux, uy, up, p;
game_state *ret;
if (!strcmp(move, "S")) {
int i;
ret = dup_game(from);
/*
* Simply replace the grid with a solved one. For this game,
* this isn't a useful operation for actually telling the user
* what they should have done, but it is useful for
* conveniently being able to get hold of a clean state from
* which to practise manoeuvres.
*/
for (i = 0; i < ret->n; i++)
ret->tiles[i] = (i+1) % ret->n;
ret->gap_pos = ret->n-1;
ret->used_solve = TRUE;
ret->completed = ret->movecount = 1;
return ret;
}
gx = X(from, from->gap_pos);
gy = Y(from, from->gap_pos);
if (move[0] != 'M' ||
sscanf(move+1, "%d,%d", &dx, &dy) != 2 ||
(dx == gx && dy == gy) || (dx != gx && dy != gy) ||
dx < 0 || dx >= from->w || dy < 0 || dy >= from->h)
return NULL;
/*
* Find the unit displacement from the original gap
* position towards this one.
*/
ux = (dx < gx ? -1 : dx > gx ? +1 : 0);
uy = (dy < gy ? -1 : dy > gy ? +1 : 0);
up = C(from, ux, uy);
ret = dup_game(from);
ret->gap_pos = C(from, dx, dy);
assert(ret->gap_pos >= 0 && ret->gap_pos < ret->n);
ret->tiles[ret->gap_pos] = 0;
for (p = from->gap_pos; p != ret->gap_pos; p += up) {
assert(p >= 0 && p < from->n);
ret->tiles[p] = from->tiles[p + up];
ret->movecount++;
}
/*
* See if the game has been completed.
*/
if (!ret->completed) {
ret->completed = ret->movecount;
for (p = 0; p < ret->n; p++)
if (ret->tiles[p] != (p < ret->n-1 ? p+1 : 0))
ret->completed = 0;
}
return ret;
}
/* ----------------------------------------------------------------------
* Drawing routines.
*/
static void game_compute_size(const game_params *params, int tilesize,
int *x, int *y)
{
/* Ick: fake up `ds->tilesize' for macro expansion purposes */
struct { int tilesize; } ads, *ds = &ads;
ads.tilesize = tilesize;
*x = TILE_SIZE * params->w + 2 * BORDER;
*y = TILE_SIZE * params->h + 2 * BORDER;
}
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);
for (i = 0; i < 3; i++)
ret[COL_TEXT * 3 + i] = 0.0;
*ncolours = NCOLOURS;
return ret;
}
static game_drawstate *game_new_drawstate(drawing *dr, const game_state *state)
{
struct game_drawstate *ds = snew(struct game_drawstate);
int i;
ds->started = FALSE;
ds->w = state->w;
ds->h = state->h;
ds->bgcolour = COL_BACKGROUND;
ds->tiles = snewn(ds->w*ds->h, int);
ds->tilesize = 0; /* haven't decided yet */
for (i = 0; i < ds->w*ds->h; i++)
ds->tiles[i] = -1;
return ds;
}
static void game_free_drawstate(drawing *dr, game_drawstate *ds)
{
sfree(ds->tiles);
sfree(ds);
}
static void draw_tile(drawing *dr, game_drawstate *ds, const game_state *state,
int x, int y, int tile, int flash_colour)
{
if (tile == 0) {
draw_rect(dr, x, y, TILE_SIZE, TILE_SIZE,
flash_colour);
} else {
int coords[6];
char str[40];
coords[0] = x + TILE_SIZE - 1;
coords[1] = y + TILE_SIZE - 1;
coords[2] = x + TILE_SIZE - 1;
coords[3] = y;
coords[4] = x;
coords[5] = y + TILE_SIZE - 1;
draw_polygon(dr, coords, 3, COL_LOWLIGHT, COL_LOWLIGHT);
coords[0] = x;
coords[1] = y;
draw_polygon(dr, coords, 3, COL_HIGHLIGHT, COL_HIGHLIGHT);
draw_rect(dr, x + HIGHLIGHT_WIDTH, y + HIGHLIGHT_WIDTH,
TILE_SIZE - 2*HIGHLIGHT_WIDTH, TILE_SIZE - 2*HIGHLIGHT_WIDTH,
flash_colour);
sprintf(str, "%d", tile);
draw_text(dr, x + TILE_SIZE/2, y + TILE_SIZE/2,
FONT_VARIABLE, TILE_SIZE/3, ALIGN_VCENTRE | ALIGN_HCENTRE,
COL_TEXT, str);
}
draw_update(dr, x, y, TILE_SIZE, TILE_SIZE);
}
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 i, pass, bgcolour;
if (flashtime > 0) {
int frame = (int)(flashtime / FLASH_FRAME);
bgcolour = (frame % 2 ? COL_LOWLIGHT : COL_HIGHLIGHT);
} else
bgcolour = COL_BACKGROUND;
if (!ds->started) {
int coords[10];
draw_rect(dr, 0, 0,
TILE_SIZE * state->w + 2 * BORDER,
TILE_SIZE * state->h + 2 * BORDER, COL_BACKGROUND);
draw_update(dr, 0, 0,
TILE_SIZE * state->w + 2 * BORDER,
TILE_SIZE * state->h + 2 * BORDER);
/*
* Recessed area containing the whole puzzle.
*/
coords[0] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
coords[1] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
coords[2] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
coords[3] = COORD(0) - HIGHLIGHT_WIDTH;
coords[4] = coords[2] - TILE_SIZE;
coords[5] = coords[3] + TILE_SIZE;
coords[8] = COORD(0) - HIGHLIGHT_WIDTH;
coords[9] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
coords[6] = coords[8] + TILE_SIZE;
coords[7] = coords[9] - TILE_SIZE;
draw_polygon(dr, coords, 5, COL_HIGHLIGHT, COL_HIGHLIGHT);
coords[1] = COORD(0) - HIGHLIGHT_WIDTH;
coords[0] = COORD(0) - HIGHLIGHT_WIDTH;
draw_polygon(dr, coords, 5, COL_LOWLIGHT, COL_LOWLIGHT);
ds->started = TRUE;
}
/*
* Now draw each tile. We do this in two passes to make
* animation easy.
*/
for (pass = 0; pass < 2; pass++) {
for (i = 0; i < state->n; i++) {
int t, t0;
/*
* Figure out what should be displayed at this
* location. It's either a simple tile, or it's a
* transition between two tiles (in which case we say
* -1 because it must always be drawn).
*/
if (oldstate && oldstate->tiles[i] != state->tiles[i])
t = -1;
else
t = state->tiles[i];
t0 = t;
if (ds->bgcolour != bgcolour || /* always redraw when flashing */
ds->tiles[i] != t || ds->tiles[i] == -1 || t == -1) {
int x, y;
/*
* Figure out what to _actually_ draw, and where to
* draw it.
*/
if (t == -1) {
int x0, y0, x1, y1;
int j;
/*
* On the first pass, just blank the tile.
*/
if (pass == 0) {
x = COORD(X(state, i));
y = COORD(Y(state, i));
t = 0;
} else {
float c;
t = state->tiles[i];
/*
* Don't bother moving the gap; just don't
* draw it.
*/
if (t == 0)
continue;
/*
* Find the coordinates of this tile in the old and
* new states.
*/
x1 = COORD(X(state, i));
y1 = COORD(Y(state, i));
for (j = 0; j < oldstate->n; j++)
if (oldstate->tiles[j] == state->tiles[i])
break;
assert(j < oldstate->n);
x0 = COORD(X(state, j));
y0 = COORD(Y(state, j));
c = (animtime / ANIM_TIME);
if (c < 0.0F) c = 0.0F;
if (c > 1.0F) c = 1.0F;
x = x0 + (int)(c * (x1 - x0));
y = y0 + (int)(c * (y1 - y0));
}
} else {
if (pass == 0)
continue;
x = COORD(X(state, i));
y = COORD(Y(state, i));
}
draw_tile(dr, ds, state, x, y, t, bgcolour);
}
ds->tiles[i] = t0;
}
}
ds->bgcolour = bgcolour;
/*
* Update the status bar.
*/
{
char statusbuf[256];
/*
* Don't show the new status until we're also showing the
* new _state_ - after the game animation is complete.
*/
if (oldstate)
state = oldstate;
if (state->used_solve)
sprintf(statusbuf, "Moves since auto-solve: %d",
state->movecount - state->completed);
else
sprintf(statusbuf, "%sMoves: %d",
(state->completed ? "COMPLETED! " : ""),
(state->completed ? state->completed : state->movecount));
status_bar(dr, statusbuf);
}
}
static float game_anim_length(const game_state *oldstate,
const game_state *newstate, int dir, game_ui *ui)
{
return ANIM_TIME;
}
static float game_flash_length(const game_state *oldstate,
const game_state *newstate, int dir, game_ui *ui)
{
if (!oldstate->completed && newstate->completed &&
!oldstate->used_solve && !newstate->used_solve)
return 2 * FLASH_FRAME;
else
return 0.0F;
}
static int game_status(const game_state *state)
{
return state->completed ? +1 : 0;
}
static int 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 fifteen
#endif
const struct game thegame = {
"Fifteen", "games.fifteen", "fifteen",
default_params,
game_fetch_preset,
decode_params,
encode_params,
free_params,
dup_params,
TRUE, game_configure, custom_params,
validate_params,
new_game_desc,
validate_desc,
new_game,
dup_game,
free_game,
TRUE, solve_game,
TRUE, game_can_format_as_text_now, game_text_format,
new_ui,
free_ui,
encode_ui,
decode_ui,
game_changed_state,
interpret_move,
execute_move,
PREFERRED_TILE_SIZE, game_compute_size, game_set_size,
game_colours,
game_new_drawstate,
game_free_drawstate,
game_redraw,
game_anim_length,
game_flash_length,
game_status,
FALSE, FALSE, game_print_size, game_print,
TRUE, /* wants_statusbar */
FALSE, game_timing_state,
0, /* flags */
};