ref: 37df1f2bbc689d224369d963dd8007d68fcd7c6a
dir: /inertia.c/
/*
* inertia.c: Game involving navigating round a grid picking up
* gems.
*
* Game rules and basic generator design by Ben Olmstead.
* This re-implementation was written by Simon Tatham.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <ctype.h>
#include <limits.h>
#include <math.h>
#include "puzzles.h"
/* Used in the game_state */
#define BLANK 'b'
#define GEM 'g'
#define MINE 'm'
#define STOP 's'
#define WALL 'w'
/* Used in the game IDs */
#define START 'S'
/* Used in the game generation */
#define POSSGEM 'G'
/* Used only in the game_drawstate*/
#define UNDRAWN '?'
#define DIRECTIONS 8
#define DP1 (DIRECTIONS+1)
#define DX(dir) ( (dir) & 3 ? (((dir) & 7) > 4 ? -1 : +1) : 0 )
#define DY(dir) ( DX((dir)+6) )
/*
* Lvalue macro which expects x and y to be in range.
*/
#define LV_AT(w, h, grid, x, y) ( (grid)[(y)*(w)+(x)] )
/*
* Rvalue macro which can cope with x and y being out of range.
*/
#define AT(w, h, grid, x, y) ( (x)<0 || (x)>=(w) || (y)<0 || (y)>=(h) ? \
WALL : LV_AT(w, h, grid, x, y) )
enum {
COL_BACKGROUND,
COL_OUTLINE,
COL_HIGHLIGHT,
COL_LOWLIGHT,
COL_PLAYER,
COL_DEAD_PLAYER,
COL_MINE,
COL_GEM,
COL_WALL,
COL_HINT,
NCOLOURS
};
struct game_params {
int w, h;
};
typedef struct soln {
int refcount;
int len;
unsigned char *list;
} soln;
struct game_state {
game_params p;
int px, py;
int gems;
char *grid;
int distance_moved;
bool dead;
bool cheated;
int solnpos;
soln *soln;
};
static game_params *default_params(void)
{
game_params *ret = snew(game_params);
ret->w = 10;
#ifdef PORTRAIT_SCREEN
ret->h = 10;
#else
ret->h = 8;
#endif
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 inertia_presets[] = {
#ifdef PORTRAIT_SCREEN
{ 10, 10 },
{ 12, 12 },
{ 16, 16 },
#else
{ 10, 8 },
{ 15, 12 },
{ 20, 16 },
#endif
};
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(inertia_presets))
return false;
p = inertia_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)
{
/*
* Avoid completely degenerate cases which only have one
* row/column. We probably could generate completable puzzles
* of that shape, but they'd be forced to be extremely boring
* and at large sizes would take a while to happen upon at
* random as well.
*/
if (params->w < 2 || params->h < 2)
return "Width and height must both be at least two";
if (params->w > INT_MAX / params->h)
return "Width times height must not be unreasonably large";
/*
* The grid construction algorithm creates 1/5 as many gems as
* grid squares, and must create at least one gem to have an
* actual puzzle. However, an area-five grid is ruled out by
* the above constraint, so the practical minimum is six.
*/
if (params->w * params->h < 6)
return "Grid area must be at least six squares";
return NULL;
}
/* ----------------------------------------------------------------------
* Solver used by grid generator.
*/
struct solver_scratch {
bool *reachable_from, *reachable_to;
int *positions;
};
static struct solver_scratch *new_scratch(int w, int h)
{
struct solver_scratch *sc = snew(struct solver_scratch);
sc->reachable_from = snewn(w * h * DIRECTIONS, bool);
sc->reachable_to = snewn(w * h * DIRECTIONS, bool);
sc->positions = snewn(w * h * DIRECTIONS, int);
return sc;
}
static void free_scratch(struct solver_scratch *sc)
{
sfree(sc->reachable_from);
sfree(sc->reachable_to);
sfree(sc->positions);
sfree(sc);
}
static bool can_go(int w, int h, char *grid,
int x1, int y1, int dir1, int x2, int y2, int dir2)
{
/*
* Returns true if we can transition directly from (x1,y1)
* going in direction dir1, to (x2,y2) going in direction dir2.
*/
/*
* If we're actually in the middle of an unoccupyable square,
* we cannot make any move.
*/
if (AT(w, h, grid, x1, y1) == WALL ||
AT(w, h, grid, x1, y1) == MINE)
return false;
/*
* If a move is capable of stopping at x1,y1,dir1, and x2,y2 is
* the same coordinate as x1,y1, then we can make the
* transition (by stopping and changing direction).
*
* For this to be the case, we have to either have a wall
* beyond x1,y1,dir1, or have a stop on x1,y1.
*/
if (x2 == x1 && y2 == y1 &&
(AT(w, h, grid, x1, y1) == STOP ||
AT(w, h, grid, x1, y1) == START ||
AT(w, h, grid, x1+DX(dir1), y1+DY(dir1)) == WALL))
return true;
/*
* If a move is capable of continuing here, then x1,y1,dir1 can
* move one space further on.
*/
if (x2 == x1+DX(dir1) && y2 == y1+DY(dir1) && dir1 == dir2 &&
(AT(w, h, grid, x2, y2) == BLANK ||
AT(w, h, grid, x2, y2) == GEM ||
AT(w, h, grid, x2, y2) == STOP ||
AT(w, h, grid, x2, y2) == START))
return true;
/*
* That's it.
*/
return false;
}
static int find_gem_candidates(int w, int h, char *grid,
struct solver_scratch *sc)
{
int wh = w*h;
int head, tail;
int sx, sy, gx, gy, gd, pass, possgems;
/*
* This function finds all the candidate gem squares, which are
* precisely those squares which can be picked up on a loop
* from the starting point back to the starting point. Doing
* this may involve passing through such a square in the middle
* of a move; so simple breadth-first search over the _squares_
* of the grid isn't quite adequate, because it might be that
* we can only reach a gem from the start by moving over it in
* one direction, but can only return to the start if we were
* moving over it in another direction.
*
* Instead, we BFS over a space which mentions each grid square
* eight times - once for each direction. We also BFS twice:
* once to find out what square+direction pairs we can reach
* _from_ the start point, and once to find out what pairs we
* can reach the start point from. Then a square is reachable
* if any of the eight directions for that square has both
* flags set.
*/
memset(sc->reachable_from, 0, wh * DIRECTIONS * sizeof(bool));
memset(sc->reachable_to, 0, wh * DIRECTIONS * sizeof(bool));
/*
* Find the starting square.
*/
sx = -1; /* placate optimiser */
for (sy = 0; sy < h; sy++) {
for (sx = 0; sx < w; sx++)
if (AT(w, h, grid, sx, sy) == START)
break;
if (sx < w)
break;
}
assert(sy < h);
for (pass = 0; pass < 2; pass++) {
bool *reachable = (pass == 0 ? sc->reachable_from : sc->reachable_to);
int sign = (pass == 0 ? +1 : -1);
int dir;
#ifdef SOLVER_DIAGNOSTICS
printf("starting pass %d\n", pass);
#endif
/*
* `head' and `tail' are indices within sc->positions which
* track the list of board positions left to process.
*/
head = tail = 0;
for (dir = 0; dir < DIRECTIONS; dir++) {
int index = (sy*w+sx)*DIRECTIONS+dir;
sc->positions[tail++] = index;
reachable[index] = true;
#ifdef SOLVER_DIAGNOSTICS
printf("starting point %d,%d,%d\n", sx, sy, dir);
#endif
}
/*
* Now repeatedly pick an element off the list and process
* it.
*/
while (head < tail) {
int index = sc->positions[head++];
int dir = index % DIRECTIONS;
int x = (index / DIRECTIONS) % w;
int y = index / (w * DIRECTIONS);
int n, x2, y2, d2, i2;
#ifdef SOLVER_DIAGNOSTICS
printf("processing point %d,%d,%d\n", x, y, dir);
#endif
/*
* The places we attempt to switch to here are:
* - each possible direction change (all the other
* directions in this square)
* - one step further in the direction we're going (or
* one step back, if we're in the reachable_to pass).
*/
for (n = -1; n < DIRECTIONS; n++) {
if (n < 0) {
x2 = x + sign * DX(dir);
y2 = y + sign * DY(dir);
d2 = dir;
} else {
x2 = x;
y2 = y;
d2 = n;
}
i2 = (y2*w+x2)*DIRECTIONS+d2;
if (x2 >= 0 && x2 < w &&
y2 >= 0 && y2 < h &&
!reachable[i2]) {
bool ok;
#ifdef SOLVER_DIAGNOSTICS
printf(" trying point %d,%d,%d", x2, y2, d2);
#endif
if (pass == 0)
ok = can_go(w, h, grid, x, y, dir, x2, y2, d2);
else
ok = can_go(w, h, grid, x2, y2, d2, x, y, dir);
#ifdef SOLVER_DIAGNOSTICS
printf(" - %sok\n", ok ? "" : "not ");
#endif
if (ok) {
sc->positions[tail++] = i2;
reachable[i2] = true;
}
}
}
}
}
/*
* And that should be it. Now all we have to do is find the
* squares for which there exists _some_ direction such that
* the square plus that direction form a tuple which is both
* reachable from the start and reachable to the start.
*/
possgems = 0;
for (gy = 0; gy < h; gy++)
for (gx = 0; gx < w; gx++)
if (AT(w, h, grid, gx, gy) == BLANK) {
for (gd = 0; gd < DIRECTIONS; gd++) {
int index = (gy*w+gx)*DIRECTIONS+gd;
if (sc->reachable_from[index] && sc->reachable_to[index]) {
#ifdef SOLVER_DIAGNOSTICS
printf("space at %d,%d is reachable via"
" direction %d\n", gx, gy, gd);
#endif
LV_AT(w, h, grid, gx, gy) = POSSGEM;
possgems++;
break;
}
}
}
return possgems;
}
/* ----------------------------------------------------------------------
* Grid generation code.
*/
static char *gengrid(int w, int h, random_state *rs)
{
int wh = w*h;
char *grid = snewn(wh+1, char);
struct solver_scratch *sc = new_scratch(w, h);
int maxdist_threshold, tries;
maxdist_threshold = 2;
tries = 0;
while (1) {
int i, j;
int possgems;
int *dist, *list, head, tail, maxdist;
/*
* We're going to fill the grid with the five basic piece
* types in about 1/5 proportion. For the moment, though,
* we leave out the gems, because we'll put those in
* _after_ we run the solver to tell us where the viable
* locations are.
*/
i = 0;
for (j = 0; j < wh/5; j++)
grid[i++] = WALL;
for (j = 0; j < wh/5; j++)
grid[i++] = STOP;
for (j = 0; j < wh/5; j++)
grid[i++] = MINE;
assert(i < wh);
grid[i++] = START;
while (i < wh)
grid[i++] = BLANK;
shuffle(grid, wh, sizeof(*grid), rs);
/*
* Find the viable gem locations, and immediately give up
* and try again if there aren't enough of them.
*/
possgems = find_gem_candidates(w, h, grid, sc);
if (possgems < wh/5)
continue;
/*
* We _could_ now select wh/5 of the POSSGEMs and set them
* to GEM, and have a viable level. However, there's a
* chance that a large chunk of the level will turn out to
* be unreachable, so first we test for that.
*
* We do this by finding the largest distance from any
* square to the nearest POSSGEM, by breadth-first search.
* If this is above a critical threshold, we abort and try
* again.
*
* (This search is purely geometric, without regard to
* walls and long ways round.)
*/
dist = sc->positions;
list = sc->positions + wh;
for (i = 0; i < wh; i++)
dist[i] = -1;
head = tail = 0;
for (i = 0; i < wh; i++)
if (grid[i] == POSSGEM) {
dist[i] = 0;
list[tail++] = i;
}
maxdist = 0;
while (head < tail) {
int pos, x, y, d;
pos = list[head++];
if (maxdist < dist[pos])
maxdist = dist[pos];
x = pos % w;
y = pos / w;
for (d = 0; d < DIRECTIONS; d++) {
int x2, y2, p2;
x2 = x + DX(d);
y2 = y + DY(d);
if (x2 >= 0 && x2 < w && y2 >= 0 && y2 < h) {
p2 = y2*w+x2;
if (dist[p2] < 0) {
dist[p2] = dist[pos] + 1;
list[tail++] = p2;
}
}
}
}
assert(head == wh && tail == wh);
/*
* Now abandon this grid and go round again if maxdist is
* above the required threshold.
*
* We can safely start the threshold as low as 2. As we
* accumulate failed generation attempts, we gradually
* raise it as we get more desperate.
*/
if (maxdist > maxdist_threshold) {
tries++;
if (tries == 50) {
maxdist_threshold++;
tries = 0;
}
continue;
}
/*
* Now our reachable squares are plausibly evenly
* distributed over the grid. I'm not actually going to
* _enforce_ that I place the gems in such a way as not to
* increase that maxdist value; I'm now just going to trust
* to the RNG to pick a sensible subset of the POSSGEMs.
*/
j = 0;
for (i = 0; i < wh; i++)
if (grid[i] == POSSGEM)
list[j++] = i;
shuffle(list, j, sizeof(*list), rs);
for (i = 0; i < j; i++)
grid[list[i]] = (i < wh/5 ? GEM : BLANK);
break;
}
free_scratch(sc);
grid[wh] = '\0';
return grid;
}
static char *new_game_desc(const game_params *params, random_state *rs,
char **aux, bool interactive)
{
return gengrid(params->w, params->h, rs);
}
static const char *validate_desc(const game_params *params, const char *desc)
{
int w = params->w, h = params->h, wh = w*h;
int starts = 0, gems = 0, i;
for (i = 0; i < wh; i++) {
if (!desc[i])
return "Not enough data to fill grid";
if (desc[i] != WALL && desc[i] != START && desc[i] != STOP &&
desc[i] != GEM && desc[i] != MINE && desc[i] != BLANK)
return "Unrecognised character in game description";
if (desc[i] == START)
starts++;
if (desc[i] == GEM)
gems++;
}
if (desc[i])
return "Too much data to fill grid";
if (starts < 1)
return "No starting square specified";
if (starts > 1)
return "More than one starting square specified";
if (gems < 1)
return "No gems specified";
return NULL;
}
static game_state *new_game(midend *me, const game_params *params,
const char *desc)
{
int w = params->w, h = params->h, wh = w*h;
int i;
game_state *state = snew(game_state);
state->p = *params; /* structure copy */
state->grid = snewn(wh, char);
assert(strlen(desc) == wh);
memcpy(state->grid, desc, wh);
state->px = state->py = -1;
state->gems = 0;
for (i = 0; i < wh; i++) {
if (state->grid[i] == START) {
state->grid[i] = STOP;
state->px = i % w;
state->py = i / w;
} else if (state->grid[i] == GEM) {
state->gems++;
}
}
assert(state->gems > 0);
assert(state->px >= 0 && state->py >= 0);
state->distance_moved = 0;
state->dead = false;
state->cheated = false;
state->solnpos = 0;
state->soln = NULL;
return state;
}
static game_state *dup_game(const game_state *state)
{
int w = state->p.w, h = state->p.h, wh = w*h;
game_state *ret = snew(game_state);
ret->p = state->p;
ret->px = state->px;
ret->py = state->py;
ret->gems = state->gems;
ret->grid = snewn(wh, char);
ret->distance_moved = state->distance_moved;
ret->dead = false;
memcpy(ret->grid, state->grid, wh);
ret->cheated = state->cheated;
ret->soln = state->soln;
if (ret->soln)
ret->soln->refcount++;
ret->solnpos = state->solnpos;
return ret;
}
static void free_game(game_state *state)
{
if (state->soln && --state->soln->refcount == 0) {
sfree(state->soln->list);
sfree(state->soln);
}
sfree(state->grid);
sfree(state);
}
/*
* Internal function used by solver.
*/
static int move_goes_to(int w, int h, char *grid, int x, int y, int d)
{
int dr;
/*
* See where we'd get to if we made this move.
*/
dr = -1; /* placate optimiser */
while (1) {
if (AT(w, h, grid, x+DX(d), y+DY(d)) == WALL) {
dr = DIRECTIONS; /* hit a wall, so end up stationary */
break;
}
x += DX(d);
y += DY(d);
if (AT(w, h, grid, x, y) == STOP) {
dr = DIRECTIONS; /* hit a stop, so end up stationary */
break;
}
if (AT(w, h, grid, x, y) == GEM) {
dr = d; /* hit a gem, so we're still moving */
break;
}
if (AT(w, h, grid, x, y) == MINE)
return -1; /* hit a mine, so move is invalid */
}
assert(dr >= 0);
return (y*w+x)*DP1+dr;
}
static int compare_integers(const void *av, const void *bv)
{
const int *a = (const int *)av;
const int *b = (const int *)bv;
if (*a < *b)
return -1;
else if (*a > *b)
return +1;
else
return 0;
}
static char *solve_game(const game_state *state, const game_state *currstate,
const char *aux, const char **error)
{
int w = currstate->p.w, h = currstate->p.h, wh = w*h;
int *nodes, *nodeindex, *edges, *backedges, *edgei, *backedgei, *circuit;
int nedges;
int *dist, *dist2, *list;
int *unvisited;
int circuitlen, circuitsize;
int head, tail, pass, i, j, n, x, y, d, dd;
const char *err;
char *soln, *p;
/*
* Before anything else, deal with the special case in which
* all the gems are already collected.
*/
for (i = 0; i < wh; i++)
if (currstate->grid[i] == GEM)
break;
if (i == wh) {
*error = "Game is already solved";
return NULL;
}
/*
* Solving Inertia is a question of first building up the graph
* of where you can get to from where, and secondly finding a
* tour of the graph which takes in every gem.
*
* This is of course a close cousin of the travelling salesman
* problem, which is NP-complete; so I rather doubt that any
* _optimal_ tour can be found in plausible time. Hence I'll
* restrict myself to merely finding a not-too-bad one.
*
* First construct the graph, by bfsing out move by move from
* the current player position. Graph vertices will be
* - every endpoint of a move (place the ball can be
* stationary)
* - every gem (place the ball can go through in motion).
* Vertices of this type have an associated direction, since
* if a gem can be collected by sliding through it in two
* different directions it doesn't follow that you can
* change direction at it.
*
* I'm going to refer to a non-directional vertex as
* (y*w+x)*DP1+DIRECTIONS, and a directional one as
* (y*w+x)*DP1+d.
*/
/*
* nodeindex[] maps node codes as shown above to numeric
* indices in the nodes[] array.
*/
nodeindex = snewn(DP1*wh, int);
for (i = 0; i < DP1*wh; i++)
nodeindex[i] = -1;
/*
* Do the bfs to find all the interesting graph nodes.
*/
nodes = snewn(DP1*wh, int);
head = tail = 0;
nodes[tail] = (currstate->py * w + currstate->px) * DP1 + DIRECTIONS;
nodeindex[nodes[0]] = tail;
tail++;
while (head < tail) {
int nc = nodes[head++], nnc;
d = nc % DP1;
/*
* Plot all possible moves from this node. If the node is
* directed, there's only one.
*/
for (dd = 0; dd < DIRECTIONS; dd++) {
x = nc / DP1;
y = x / w;
x %= w;
if (d < DIRECTIONS && d != dd)
continue;
nnc = move_goes_to(w, h, currstate->grid, x, y, dd);
if (nnc >= 0 && nnc != nc) {
if (nodeindex[nnc] < 0) {
nodes[tail] = nnc;
nodeindex[nnc] = tail;
tail++;
}
}
}
}
n = head;
/*
* Now we know how many nodes we have, allocate the edge array
* and go through setting up the edges.
*/
edges = snewn(DIRECTIONS*n, int);
edgei = snewn(n+1, int);
nedges = 0;
for (i = 0; i < n; i++) {
int nc = nodes[i];
edgei[i] = nedges;
d = nc % DP1;
x = nc / DP1;
y = x / w;
x %= w;
for (dd = 0; dd < DIRECTIONS; dd++) {
int nnc;
if (d >= DIRECTIONS || d == dd) {
nnc = move_goes_to(w, h, currstate->grid, x, y, dd);
if (nnc >= 0 && nnc != nc)
edges[nedges++] = nodeindex[nnc];
}
}
}
edgei[n] = nedges;
/*
* Now set up the backedges array.
*/
backedges = snewn(nedges, int);
backedgei = snewn(n+1, int);
for (i = j = 0; i < nedges; i++) {
while (j+1 < n && i >= edgei[j+1])
j++;
backedges[i] = edges[i] * n + j;
}
qsort(backedges, nedges, sizeof(int), compare_integers);
backedgei[0] = 0;
for (i = j = 0; i < nedges; i++) {
int k = backedges[i] / n;
backedges[i] %= n;
while (j < k)
backedgei[++j] = i;
}
backedgei[n] = nedges;
/*
* Set up the initial tour. At all times, our tour is a circuit
* of graph vertices (which may, and probably will often,
* repeat vertices). To begin with, it's got exactly one vertex
* in it, which is the player's current starting point.
*/
circuitsize = 256;
circuit = snewn(circuitsize, int);
circuitlen = 0;
circuit[circuitlen++] = 0; /* node index 0 is the starting posn */
/*
* Track which gems are as yet unvisited.
*/
unvisited = snewn(wh, int);
for (i = 0; i < wh; i++)
unvisited[i] = false;
for (i = 0; i < wh; i++)
if (currstate->grid[i] == GEM)
unvisited[i] = true;
/*
* Allocate space for doing bfses inside the main loop.
*/
dist = snewn(n, int);
dist2 = snewn(n, int);
list = snewn(n, int);
err = NULL;
soln = NULL;
/*
* Now enter the main loop, in each iteration of which we
* extend the tour to take in an as yet uncollected gem.
*/
while (1) {
int target, n1, n2, bestdist, extralen, targetpos;
#ifdef TSP_DIAGNOSTICS
printf("circuit is");
for (i = 0; i < circuitlen; i++) {
int nc = nodes[circuit[i]];
printf(" (%d,%d,%d)", nc/DP1%w, nc/(DP1*w), nc%DP1);
}
printf("\n");
printf("moves are ");
x = nodes[circuit[0]] / DP1 % w;
y = nodes[circuit[0]] / DP1 / w;
for (i = 1; i < circuitlen; i++) {
int x2, y2, dx, dy;
if (nodes[circuit[i]] % DP1 != DIRECTIONS)
continue;
x2 = nodes[circuit[i]] / DP1 % w;
y2 = nodes[circuit[i]] / DP1 / w;
dx = (x2 > x ? +1 : x2 < x ? -1 : 0);
dy = (y2 > y ? +1 : y2 < y ? -1 : 0);
for (d = 0; d < DIRECTIONS; d++)
if (DX(d) == dx && DY(d) == dy)
printf("%c", "89632147"[d]);
x = x2;
y = y2;
}
printf("\n");
#endif
/*
* First, start a pair of bfses at _every_ vertex currently
* in the tour, and extend them outwards to find the
* nearest as yet unreached gem vertex.
*
* This is largely a heuristic: we could pick _any_ doubly
* reachable node here and still get a valid tour as
* output. I hope that picking a nearby one will result in
* generally good tours.
*/
for (pass = 0; pass < 2; pass++) {
int *ep = (pass == 0 ? edges : backedges);
int *ei = (pass == 0 ? edgei : backedgei);
int *dp = (pass == 0 ? dist : dist2);
head = tail = 0;
for (i = 0; i < n; i++)
dp[i] = -1;
for (i = 0; i < circuitlen; i++) {
int ni = circuit[i];
if (dp[ni] < 0) {
dp[ni] = 0;
list[tail++] = ni;
}
}
while (head < tail) {
int ni = list[head++];
for (i = ei[ni]; i < ei[ni+1]; i++) {
int ti = ep[i];
if (ti >= 0 && dp[ti] < 0) {
dp[ti] = dp[ni] + 1;
list[tail++] = ti;
}
}
}
}
/* Now find the nearest unvisited gem. */
bestdist = -1;
target = -1;
for (i = 0; i < n; i++) {
if (unvisited[nodes[i] / DP1] &&
dist[i] >= 0 && dist2[i] >= 0) {
int thisdist = dist[i] + dist2[i];
if (bestdist < 0 || bestdist > thisdist) {
bestdist = thisdist;
target = i;
}
}
}
if (target < 0) {
/*
* If we get to here, we haven't found a gem we can get
* at all, which means we terminate this loop.
*/
break;
}
/*
* Now we have a graph vertex at list[tail-1] which is an
* unvisited gem. We want to add that vertex to our tour.
* So we run two more breadth-first searches: one starting
* from that vertex and following forward edges, and
* another starting from the same vertex and following
* backward edges. This allows us to determine, for each
* node on the current tour, how quickly we can get both to
* and from the target vertex from that node.
*/
#ifdef TSP_DIAGNOSTICS
printf("target node is %d (%d,%d,%d)\n", target, nodes[target]/DP1%w,
nodes[target]/DP1/w, nodes[target]%DP1);
#endif
for (pass = 0; pass < 2; pass++) {
int *ep = (pass == 0 ? edges : backedges);
int *ei = (pass == 0 ? edgei : backedgei);
int *dp = (pass == 0 ? dist : dist2);
for (i = 0; i < n; i++)
dp[i] = -1;
head = tail = 0;
dp[target] = 0;
list[tail++] = target;
while (head < tail) {
int ni = list[head++];
for (i = ei[ni]; i < ei[ni+1]; i++) {
int ti = ep[i];
if (ti >= 0 && dp[ti] < 0) {
dp[ti] = dp[ni] + 1;
/*printf("pass %d: set dist of vertex %d to %d (via %d)\n", pass, ti, dp[ti], ni);*/
list[tail++] = ti;
}
}
}
}
/*
* Now for every node n, dist[n] gives the length of the
* shortest path from the target vertex to n, and dist2[n]
* gives the length of the shortest path from n to the
* target vertex.
*
* Our next step is to search linearly along the tour to
* find the optimum place to insert a trip to the target
* vertex and back. Our two options are either
* (a) to find two adjacent vertices A,B in the tour and
* replace the edge A->B with the path A->target->B
* (b) to find a single vertex X in the tour and replace
* it with the complete round trip X->target->X.
* We do whichever takes the fewest moves.
*/
n1 = n2 = -1;
bestdist = -1;
for (i = 0; i < circuitlen; i++) {
int thisdist;
/*
* Try a round trip from vertex i.
*/
if (dist[circuit[i]] >= 0 &&
dist2[circuit[i]] >= 0) {
thisdist = dist[circuit[i]] + dist2[circuit[i]];
if (bestdist < 0 || thisdist < bestdist) {
bestdist = thisdist;
n1 = n2 = i;
}
}
/*
* Try a trip from vertex i via target to vertex i+1.
*/
if (i+1 < circuitlen &&
dist2[circuit[i]] >= 0 &&
dist[circuit[i+1]] >= 0) {
thisdist = dist2[circuit[i]] + dist[circuit[i+1]];
if (bestdist < 0 || thisdist < bestdist) {
bestdist = thisdist;
n1 = i;
n2 = i+1;
}
}
}
if (bestdist < 0) {
/*
* We couldn't find a round trip taking in this gem _at
* all_. Give up.
*/
err = "Unable to find a solution from this starting point";
break;
}
#ifdef TSP_DIAGNOSTICS
printf("insertion point: n1=%d, n2=%d, dist=%d\n", n1, n2, bestdist);
#endif
#ifdef TSP_DIAGNOSTICS
printf("circuit before lengthening is");
for (i = 0; i < circuitlen; i++) {
printf(" %d", circuit[i]);
}
printf("\n");
#endif
/*
* Now actually lengthen the tour to take in this round
* trip.
*/
extralen = dist2[circuit[n1]] + dist[circuit[n2]];
if (n1 != n2)
extralen--;
circuitlen += extralen;
if (circuitlen >= circuitsize) {
circuitsize = circuitlen + 256;
circuit = sresize(circuit, circuitsize, int);
}
memmove(circuit + n2 + extralen, circuit + n2,
(circuitlen - n2 - extralen) * sizeof(int));
n2 += extralen;
#ifdef TSP_DIAGNOSTICS
printf("circuit in middle of lengthening is");
for (i = 0; i < circuitlen; i++) {
printf(" %d", circuit[i]);
}
printf("\n");
#endif
/*
* Find the shortest-path routes to and from the target,
* and write them into the circuit.
*/
targetpos = n1 + dist2[circuit[n1]];
assert(targetpos - dist2[circuit[n1]] == n1);
assert(targetpos + dist[circuit[n2]] == n2);
for (pass = 0; pass < 2; pass++) {
int dir = (pass == 0 ? -1 : +1);
int *ep = (pass == 0 ? backedges : edges);
int *ei = (pass == 0 ? backedgei : edgei);
int *dp = (pass == 0 ? dist : dist2);
int nn = (pass == 0 ? n2 : n1);
int ni = circuit[nn], ti, dest = nn;
while (1) {
circuit[dest] = ni;
if (dp[ni] == 0)
break;
dest += dir;
ti = -1;
/*printf("pass %d: looking at vertex %d\n", pass, ni);*/
for (i = ei[ni]; i < ei[ni+1]; i++) {
ti = ep[i];
if (ti >= 0 && dp[ti] == dp[ni] - 1)
break;
}
assert(i < ei[ni+1] && ti >= 0);
ni = ti;
}
}
#ifdef TSP_DIAGNOSTICS
printf("circuit after lengthening is");
for (i = 0; i < circuitlen; i++) {
printf(" %d", circuit[i]);
}
printf("\n");
#endif
/*
* Finally, mark all gems that the new piece of circuit
* passes through as visited.
*/
for (i = n1; i <= n2; i++) {
int pos = nodes[circuit[i]] / DP1;
assert(pos >= 0 && pos < wh);
unvisited[pos] = false;
}
}
#ifdef TSP_DIAGNOSTICS
printf("before reduction, moves are ");
x = nodes[circuit[0]] / DP1 % w;
y = nodes[circuit[0]] / DP1 / w;
for (i = 1; i < circuitlen; i++) {
int x2, y2, dx, dy;
if (nodes[circuit[i]] % DP1 != DIRECTIONS)
continue;
x2 = nodes[circuit[i]] / DP1 % w;
y2 = nodes[circuit[i]] / DP1 / w;
dx = (x2 > x ? +1 : x2 < x ? -1 : 0);
dy = (y2 > y ? +1 : y2 < y ? -1 : 0);
for (d = 0; d < DIRECTIONS; d++)
if (DX(d) == dx && DY(d) == dy)
printf("%c", "89632147"[d]);
x = x2;
y = y2;
}
printf("\n");
#endif
/*
* That's got a basic solution. Now optimise it by removing
* redundant sections of the circuit: it's entirely possible
* that a piece of circuit we carefully inserted at one stage
* to collect a gem has become pointless because the steps
* required to collect some _later_ gem necessarily passed
* through the same one.
*
* So first we go through and work out how many times each gem
* is collected. Then we look for maximal sections of circuit
* which are redundant in the sense that their removal would
* not reduce any gem's collection count to zero, and replace
* each one with a bfs-derived fastest path between their
* endpoints.
*/
while (1) {
int oldlen = circuitlen;
int dir;
for (dir = +1; dir >= -1; dir -= 2) {
for (i = 0; i < wh; i++)
unvisited[i] = 0;
for (i = 0; i < circuitlen; i++) {
int xy = nodes[circuit[i]] / DP1;
if (currstate->grid[xy] == GEM)
unvisited[xy]++;
}
/*
* If there's any gem we didn't end up visiting at all,
* give up.
*/
for (i = 0; i < wh; i++) {
if (currstate->grid[i] == GEM && unvisited[i] == 0) {
err = "Unable to find a solution from this starting point";
break;
}
}
if (i < wh)
break;
for (i = j = (dir > 0 ? 0 : circuitlen-1);
i < circuitlen && i >= 0;
i += dir) {
int xy = nodes[circuit[i]] / DP1;
if (currstate->grid[xy] == GEM && unvisited[xy] > 1) {
unvisited[xy]--;
} else if (currstate->grid[xy] == GEM || i == circuitlen-1) {
/*
* circuit[i] collects a gem for the only time,
* or is the last node in the circuit.
* Therefore it cannot be removed; so we now
* want to replace the path from circuit[j] to
* circuit[i] with a bfs-shortest path.
*/
int p, q, k, dest, ni, ti, thisdist;
/*
* Set up the upper and lower bounds of the
* reduced section.
*/
p = min(i, j);
q = max(i, j);
#ifdef TSP_DIAGNOSTICS
printf("optimising section from %d - %d\n", p, q);
#endif
for (k = 0; k < n; k++)
dist[k] = -1;
head = tail = 0;
dist[circuit[p]] = 0;
list[tail++] = circuit[p];
while (head < tail && dist[circuit[q]] < 0) {
int ni = list[head++];
for (k = edgei[ni]; k < edgei[ni+1]; k++) {
int ti = edges[k];
if (ti >= 0 && dist[ti] < 0) {
dist[ti] = dist[ni] + 1;
list[tail++] = ti;
}
}
}
thisdist = dist[circuit[q]];
assert(thisdist >= 0 && thisdist <= q-p);
memmove(circuit+p+thisdist, circuit+q,
(circuitlen - q) * sizeof(int));
circuitlen -= q-p;
q = p + thisdist;
circuitlen += q-p;
if (dir > 0)
i = q; /* resume loop from the right place */
#ifdef TSP_DIAGNOSTICS
printf("new section runs from %d - %d\n", p, q);
#endif
dest = q;
assert(dest >= 0);
ni = circuit[q];
while (1) {
/* printf("dest=%d circuitlen=%d ni=%d dist[ni]=%d\n", dest, circuitlen, ni, dist[ni]); */
circuit[dest] = ni;
if (dist[ni] == 0)
break;
dest--;
ti = -1;
for (k = backedgei[ni]; k < backedgei[ni+1]; k++) {
ti = backedges[k];
if (ti >= 0 && dist[ti] == dist[ni] - 1)
break;
}
assert(k < backedgei[ni+1] && ti >= 0);
ni = ti;
}
/*
* Now re-increment the visit counts for the
* new path.
*/
while (++p < q) {
int xy = nodes[circuit[p]] / DP1;
if (currstate->grid[xy] == GEM)
unvisited[xy]++;
}
j = i;
#ifdef TSP_DIAGNOSTICS
printf("during reduction, circuit is");
for (k = 0; k < circuitlen; k++) {
int nc = nodes[circuit[k]];
printf(" (%d,%d,%d)", nc/DP1%w, nc/(DP1*w), nc%DP1);
}
printf("\n");
printf("moves are ");
x = nodes[circuit[0]] / DP1 % w;
y = nodes[circuit[0]] / DP1 / w;
for (k = 1; k < circuitlen; k++) {
int x2, y2, dx, dy;
if (nodes[circuit[k]] % DP1 != DIRECTIONS)
continue;
x2 = nodes[circuit[k]] / DP1 % w;
y2 = nodes[circuit[k]] / DP1 / w;
dx = (x2 > x ? +1 : x2 < x ? -1 : 0);
dy = (y2 > y ? +1 : y2 < y ? -1 : 0);
for (d = 0; d < DIRECTIONS; d++)
if (DX(d) == dx && DY(d) == dy)
printf("%c", "89632147"[d]);
x = x2;
y = y2;
}
printf("\n");
#endif
}
}
#ifdef TSP_DIAGNOSTICS
printf("after reduction, moves are ");
x = nodes[circuit[0]] / DP1 % w;
y = nodes[circuit[0]] / DP1 / w;
for (i = 1; i < circuitlen; i++) {
int x2, y2, dx, dy;
if (nodes[circuit[i]] % DP1 != DIRECTIONS)
continue;
x2 = nodes[circuit[i]] / DP1 % w;
y2 = nodes[circuit[i]] / DP1 / w;
dx = (x2 > x ? +1 : x2 < x ? -1 : 0);
dy = (y2 > y ? +1 : y2 < y ? -1 : 0);
for (d = 0; d < DIRECTIONS; d++)
if (DX(d) == dx && DY(d) == dy)
printf("%c", "89632147"[d]);
x = x2;
y = y2;
}
printf("\n");
#endif
}
/*
* If we've managed an entire reduction pass in each
* direction and not made the solution any shorter, we're
* _really_ done.
*/
if (circuitlen == oldlen)
break;
}
/*
* Encode the solution as a move string.
*/
if (!err) {
soln = snewn(circuitlen+2, char);
p = soln;
*p++ = 'S';
x = nodes[circuit[0]] / DP1 % w;
y = nodes[circuit[0]] / DP1 / w;
for (i = 1; i < circuitlen; i++) {
int x2, y2, dx, dy;
if (nodes[circuit[i]] % DP1 != DIRECTIONS)
continue;
x2 = nodes[circuit[i]] / DP1 % w;
y2 = nodes[circuit[i]] / DP1 / w;
dx = (x2 > x ? +1 : x2 < x ? -1 : 0);
dy = (y2 > y ? +1 : y2 < y ? -1 : 0);
for (d = 0; d < DIRECTIONS; d++)
if (DX(d) == dx && DY(d) == dy) {
*p++ = '0' + d;
break;
}
assert(d < DIRECTIONS);
x = x2;
y = y2;
}
*p++ = '\0';
assert(p - soln < circuitlen+2);
}
sfree(list);
sfree(dist);
sfree(dist2);
sfree(unvisited);
sfree(circuit);
sfree(backedgei);
sfree(backedges);
sfree(edgei);
sfree(edges);
sfree(nodeindex);
sfree(nodes);
if (err)
*error = err;
return soln;
}
static bool game_can_format_as_text_now(const game_params *params)
{
return true;
}
static char *game_text_format(const game_state *state)
{
int w = state->p.w, h = state->p.h, r, c;
int cw = 4, ch = 2, gw = cw*w + 2, gh = ch * h + 1, len = gw * gh;
char *board = snewn(len + 1, char);
sprintf(board, "%*s+\n", len - 2, "");
for (r = 0; r < h; ++r) {
for (c = 0; c < w; ++c) {
int cell = r*ch*gw + cw*c, center = cell + gw*ch/2 + cw/2;
int i = r*w + c;
switch (state->grid[i]) {
case BLANK: break;
case GEM: board[center] = 'o'; break;
case MINE: board[center] = 'M'; break;
case STOP: board[center-1] = '('; board[center+1] = ')'; break;
case WALL: memset(board + center - 1, 'X', 3);
}
if (r == state->py && c == state->px) {
if (!state->dead) board[center] = '@';
else memcpy(board + center - 1, ":-(", 3);
}
board[cell] = '+';
memset(board + cell + 1, '-', cw - 1);
for (i = 1; i < ch; ++i) board[cell + i*gw] = '|';
}
for (c = 0; c < ch; ++c) {
board[(r*ch+c)*gw + gw - 2] = "|+"[!c];
board[(r*ch+c)*gw + gw - 1] = '\n';
}
}
memset(board + len - gw, '-', gw - 2);
for (c = 0; c < w; ++c) board[len - gw + cw*c] = '+';
return board;
}
struct game_ui {
float anim_length;
int flashtype;
int deaths;
bool just_made_move;
bool just_died;
};
static game_ui *new_ui(const game_state *state)
{
game_ui *ui = snew(game_ui);
ui->anim_length = 0.0F;
ui->flashtype = 0;
ui->deaths = 0;
ui->just_made_move = false;
ui->just_died = false;
return ui;
}
static void free_ui(game_ui *ui)
{
sfree(ui);
}
static char *encode_ui(const game_ui *ui)
{
char buf[80];
/*
* The deaths counter needs preserving across a serialisation.
*/
sprintf(buf, "D%d", ui->deaths);
return dupstr(buf);
}
static void decode_ui(game_ui *ui, const char *encoding)
{
int p = 0;
sscanf(encoding, "D%d%n", &ui->deaths, &p);
}
static void game_changed_state(game_ui *ui, const game_state *oldstate,
const game_state *newstate)
{
/*
* Increment the deaths counter. We only do this if
* ui->just_made_move is set (redoing a suicide move doesn't
* kill you _again_), and also we only do it if the game wasn't
* already completed (once you're finished, you can play).
*/
if (!oldstate->dead && newstate->dead && ui->just_made_move &&
oldstate->gems) {
ui->deaths++;
ui->just_died = true;
} else {
ui->just_died = false;
}
ui->just_made_move = false;
}
static const char *current_key_label(const game_ui *ui,
const game_state *state, int button)
{
if (IS_CURSOR_SELECT(button) &&
state->soln && state->solnpos < state->soln->len)
return "Advance";
return "";
}
struct game_drawstate {
game_params p;
int tilesize;
bool started;
unsigned short *grid;
blitter *player_background;
bool player_bg_saved;
int pbgx, pbgy;
};
#define PREFERRED_TILESIZE 32
#define TILESIZE (ds->tilesize)
#ifdef SMALL_SCREEN
#define BORDER (TILESIZE / 4)
#else
#define BORDER (TILESIZE)
#endif
#define HIGHLIGHT_WIDTH (TILESIZE / 10)
#define COORD(x) ( (x) * TILESIZE + BORDER )
#define FROMCOORD(x) ( ((x) - BORDER + TILESIZE) / TILESIZE - 1 )
static char *interpret_move(const game_state *state, game_ui *ui,
const game_drawstate *ds,
int x, int y, int button)
{
int w = state->p.w, h = state->p.h /*, wh = w*h */;
int dir;
char buf[80];
dir = -1;
if (button == LEFT_BUTTON) {
/*
* Mouse-clicking near the target point (or, more
* accurately, in the appropriate octant) is an alternative
* way to input moves.
*/
if (FROMCOORD(x) != state->px || FROMCOORD(y) != state->py) {
int dx, dy;
float angle;
dx = FROMCOORD(x) - state->px;
dy = FROMCOORD(y) - state->py;
/* I pass dx,dy rather than dy,dx so that the octants
* end up the right way round. */
angle = atan2(dx, -dy);
angle = (angle + (PI/8)) / (PI/4);
assert(angle > -16.0F);
dir = (int)(angle + 16.0F) & 7;
}
} else if (button == CURSOR_UP || button == (MOD_NUM_KEYPAD | '8'))
dir = 0;
else if (button == CURSOR_DOWN || button == (MOD_NUM_KEYPAD | '2'))
dir = 4;
else if (button == CURSOR_LEFT || button == (MOD_NUM_KEYPAD | '4'))
dir = 6;
else if (button == CURSOR_RIGHT || button == (MOD_NUM_KEYPAD | '6'))
dir = 2;
else if (button == (MOD_NUM_KEYPAD | '7'))
dir = 7;
else if (button == (MOD_NUM_KEYPAD | '1'))
dir = 5;
else if (button == (MOD_NUM_KEYPAD | '9'))
dir = 1;
else if (button == (MOD_NUM_KEYPAD | '3'))
dir = 3;
else if (IS_CURSOR_SELECT(button) &&
state->soln && state->solnpos < state->soln->len)
dir = state->soln->list[state->solnpos];
if (dir < 0)
return NULL;
/*
* Reject the move if we can't make it at all due to a wall
* being in the way.
*/
if (AT(w, h, state->grid, state->px+DX(dir), state->py+DY(dir)) == WALL)
return NULL;
/*
* Reject the move if we're dead!
*/
if (state->dead)
return NULL;
/*
* Otherwise, we can make the move. All we need to specify is
* the direction.
*/
ui->just_made_move = true;
sprintf(buf, "%d", dir);
return dupstr(buf);
}
static void install_new_solution(game_state *ret, const char *move)
{
int i;
soln *sol;
assert (*move == 'S');
++move;
sol = snew(soln);
sol->len = strlen(move);
sol->list = snewn(sol->len, unsigned char);
for (i = 0; i < sol->len; ++i) sol->list[i] = move[i] - '0';
if (ret->soln && --ret->soln->refcount == 0) {
sfree(ret->soln->list);
sfree(ret->soln);
}
ret->soln = sol;
sol->refcount = 1;
ret->cheated = true;
ret->solnpos = 0;
}
static void discard_solution(game_state *ret)
{
--ret->soln->refcount;
assert(ret->soln->refcount > 0); /* ret has a soln-pointing dup */
ret->soln = NULL;
ret->solnpos = 0;
}
static game_state *execute_move(const game_state *state, const char *move)
{
int w = state->p.w, h = state->p.h /*, wh = w*h */;
int dir;
game_state *ret;
if (*move == 'S') {
/*
* This is a solve move, so we don't actually _change_ the
* grid but merely set up a stored solution path.
*/
ret = dup_game(state);
install_new_solution(ret, move);
return ret;
}
dir = atoi(move);
if (dir < 0 || dir >= DIRECTIONS)
return NULL; /* huh? */
if (state->dead)
return NULL;
if (AT(w, h, state->grid, state->px+DX(dir), state->py+DY(dir)) == WALL)
return NULL; /* wall in the way! */
/*
* Now make the move.
*/
ret = dup_game(state);
ret->distance_moved = 0;
while (1) {
ret->px += DX(dir);
ret->py += DY(dir);
ret->distance_moved++;
if (AT(w, h, ret->grid, ret->px, ret->py) == GEM) {
LV_AT(w, h, ret->grid, ret->px, ret->py) = BLANK;
ret->gems--;
}
if (AT(w, h, ret->grid, ret->px, ret->py) == MINE) {
ret->dead = true;
break;
}
if (AT(w, h, ret->grid, ret->px, ret->py) == STOP ||
AT(w, h, ret->grid, ret->px+DX(dir),
ret->py+DY(dir)) == WALL)
break;
}
if (ret->soln) {
if (ret->dead || ret->gems == 0)
discard_solution(ret);
else if (ret->soln->list[ret->solnpos] == dir) {
++ret->solnpos;
assert(ret->solnpos < ret->soln->len); /* or gems == 0 */
assert(!ret->dead); /* or not a solution */
} else {
const char *error = NULL;
char *soln = solve_game(NULL, ret, NULL, &error);
if (!error) {
install_new_solution(ret, soln);
sfree(soln);
} else discard_solution(ret);
}
}
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 = 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;
assert(!ds->player_background); /* set_size is never called twice */
assert(!ds->player_bg_saved);
ds->player_background = blitter_new(dr, 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_DEAD_PLAYER * 3 + 0] = 1.0F;
ret[COL_DEAD_PLAYER * 3 + 1] = 0.0F;
ret[COL_DEAD_PLAYER * 3 + 2] = 0.0F;
ret[COL_MINE * 3 + 0] = 0.0F;
ret[COL_MINE * 3 + 1] = 0.0F;
ret[COL_MINE * 3 + 2] = 0.0F;
ret[COL_GEM * 3 + 0] = 0.6F;
ret[COL_GEM * 3 + 1] = 1.0F;
ret[COL_GEM * 3 + 2] = 1.0F;
for (i = 0; i < 3; i++) {
ret[COL_WALL * 3 + i] = (3 * ret[COL_BACKGROUND * 3 + i] +
1 * ret[COL_HIGHLIGHT * 3 + i]) / 4;
}
ret[COL_HINT * 3 + 0] = 1.0F;
ret[COL_HINT * 3 + 1] = 1.0F;
ret[COL_HINT * 3 + 2] = 0.0F;
*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, wh = w*h;
struct game_drawstate *ds = snew(struct game_drawstate);
int i;
ds->tilesize = 0;
/* We can't allocate the blitter rectangle for the player background
* until we know what size to make it. */
ds->player_background = NULL;
ds->player_bg_saved = false;
ds->pbgx = ds->pbgy = -1;
ds->p = state->p; /* structure copy */
ds->started = false;
ds->grid = snewn(wh, unsigned short);
for (i = 0; i < wh; i++)
ds->grid[i] = UNDRAWN;
return ds;
}
static void game_free_drawstate(drawing *dr, game_drawstate *ds)
{
if (ds->player_background)
blitter_free(dr, ds->player_background);
sfree(ds->grid);
sfree(ds);
}
static void draw_player(drawing *dr, game_drawstate *ds, int x, int y,
bool dead, int hintdir)
{
if (dead) {
int coords[DIRECTIONS*4];
int d;
for (d = 0; d < DIRECTIONS; d++) {
float x1, y1, x2, y2, x3, y3, len;
x1 = DX(d);
y1 = DY(d);
len = sqrt(x1*x1+y1*y1); x1 /= len; y1 /= len;
x3 = DX(d+1);
y3 = DY(d+1);
len = sqrt(x3*x3+y3*y3); x3 /= len; y3 /= len;
x2 = (x1+x3) / 4;
y2 = (y1+y3) / 4;
coords[d*4+0] = x + TILESIZE/2 + (int)((TILESIZE*3/7) * x1);
coords[d*4+1] = y + TILESIZE/2 + (int)((TILESIZE*3/7) * y1);
coords[d*4+2] = x + TILESIZE/2 + (int)((TILESIZE*3/7) * x2);
coords[d*4+3] = y + TILESIZE/2 + (int)((TILESIZE*3/7) * y2);
}
draw_polygon(dr, coords, DIRECTIONS*2, COL_DEAD_PLAYER, COL_OUTLINE);
} else {
draw_circle(dr, x + TILESIZE/2, y + TILESIZE/2,
TILESIZE/3, COL_PLAYER, COL_OUTLINE);
}
if (!dead && hintdir >= 0) {
float scale = (DX(hintdir) && DY(hintdir) ? 0.8F : 1.0F);
int ax = (TILESIZE*2/5) * scale * DX(hintdir);
int ay = (TILESIZE*2/5) * scale * DY(hintdir);
int px = -ay, py = ax;
int ox = x + TILESIZE/2, oy = y + TILESIZE/2;
int coords[14], *c;
c = coords;
*c++ = ox + px/9;
*c++ = oy + py/9;
*c++ = ox + px/9 + ax*2/3;
*c++ = oy + py/9 + ay*2/3;
*c++ = ox + px/3 + ax*2/3;
*c++ = oy + py/3 + ay*2/3;
*c++ = ox + ax;
*c++ = oy + ay;
*c++ = ox - px/3 + ax*2/3;
*c++ = oy - py/3 + ay*2/3;
*c++ = ox - px/9 + ax*2/3;
*c++ = oy - py/9 + ay*2/3;
*c++ = ox - px/9;
*c++ = oy - py/9;
draw_polygon(dr, coords, 7, COL_HINT, COL_OUTLINE);
}
draw_update(dr, x, y, TILESIZE, TILESIZE);
}
#define FLASH_DEAD 0x100
#define FLASH_WIN 0x200
#define FLASH_MASK 0x300
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 & FLASH_DEAD ? COL_DEAD_PLAYER :
v & FLASH_WIN ? COL_HIGHLIGHT : COL_BACKGROUND);
v &= ~FLASH_MASK;
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 == MINE) {
int cx = tx + TILESIZE / 2;
int cy = ty + TILESIZE / 2;
int r = TILESIZE / 2 - 3;
draw_circle(dr, cx, cy, 5*r/6, COL_MINE, COL_MINE);
draw_rect(dr, cx - r/6, cy - r, 2*(r/6)+1, 2*r+1, COL_MINE);
draw_rect(dr, cx - r, cy - r/6, 2*r+1, 2*(r/6)+1, COL_MINE);
draw_rect(dr, cx-r/3, cy-r/3, r/3, r/4, COL_HIGHLIGHT);
} else if (v == STOP) {
draw_circle(dr, tx + TILESIZE/2, ty + TILESIZE/2,
TILESIZE*3/7, -1, COL_OUTLINE);
draw_rect(dr, tx + TILESIZE*3/7, ty+1,
TILESIZE - 2*(TILESIZE*3/7) + 1, TILESIZE-1, bg);
draw_rect(dr, tx+1, ty + TILESIZE*3/7,
TILESIZE-1, TILESIZE - 2*(TILESIZE*3/7) + 1, bg);
} else if (v == GEM) {
int coords[8];
coords[0] = tx+TILESIZE/2;
coords[1] = ty+TILESIZE/2-TILESIZE*5/14;
coords[2] = tx+TILESIZE/2-TILESIZE*5/14;
coords[3] = ty+TILESIZE/2;
coords[4] = tx+TILESIZE/2;
coords[5] = ty+TILESIZE/2+TILESIZE*5/14;
coords[6] = tx+TILESIZE/2+TILESIZE*5/14;
coords[7] = ty+TILESIZE/2;
draw_polygon(dr, coords, 4, COL_GEM, COL_OUTLINE);
}
unclip(dr);
draw_update(dr, tx, ty, TILESIZE, TILESIZE);
}
#define BASE_ANIM_LENGTH 0.1F
#define FLASH_LENGTH 0.3F
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;
float ap;
int player_dist;
int flashtype;
int gems, deaths;
char status[256];
if (flashtime &&
!((int)(flashtime * 3 / FLASH_LENGTH) % 2))
flashtype = ui->flashtype;
else
flashtype = 0;
/*
* Erase the player sprite.
*/
if (ds->player_bg_saved) {
assert(ds->player_background);
blitter_load(dr, ds->player_background, ds->pbgx, ds->pbgy);
draw_update(dr, ds->pbgx, ds->pbgy, TILESIZE, TILESIZE);
ds->player_bg_saved = false;
}
/*
* 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;
}
/*
* If we're in the process of animating a move, let's start by
* working out how far the player has moved from their _older_
* state.
*/
if (oldstate) {
ap = animtime / ui->anim_length;
player_dist = ap * (dir > 0 ? state : oldstate)->distance_moved;
} else {
player_dist = 0;
ap = 0.0F;
}
/*
* Draw the grid contents.
*
* We count the gems as we go round this loop, for the purposes
* of the status bar. Of course we have a gems counter in the
* game_state already, but if we do the counting in this loop
* then it tracks gems being picked up in a sliding move, and
* updates one by one.
*/
gems = 0;
for (y = 0; y < h; y++)
for (x = 0; x < w; x++) {
unsigned short v = (unsigned char)state->grid[y*w+x];
/*
* Special case: if the player is in the process of
* moving over a gem, we draw the gem iff they haven't
* gone past it yet.
*/
if (oldstate && oldstate->grid[y*w+x] != state->grid[y*w+x]) {
/*
* Compute the distance from this square to the
* original player position.
*/
int dist = max(abs(x - oldstate->px), abs(y - oldstate->py));
/*
* If the player has reached here, use the new grid
* element. Otherwise use the old one.
*/
if (player_dist < dist)
v = oldstate->grid[y*w+x];
else
v = state->grid[y*w+x];
}
/*
* Special case: erase the mine the dead player is
* sitting on. Only at the end of the move.
*/
if (v == MINE && !oldstate && state->dead &&
x == state->px && y == state->py)
v = BLANK;
if (v == GEM)
gems++;
v |= flashtype;
if (ds->grid[y*w+x] != v) {
draw_tile(dr, ds, x, y, v);
ds->grid[y*w+x] = v;
}
}
/*
* Gem counter in the status bar. We replace it with
* `COMPLETED!' when it reaches zero ... or rather, when the
* _current state_'s gem counter is zero. (Thus, `Gems: 0' is
* shown between the collection of the last gem and the
* completion of the move animation that did it.)
*/
if (state->dead && (!oldstate || oldstate->dead)) {
sprintf(status, "DEAD!");
} else if (state->gems || (oldstate && oldstate->gems)) {
if (state->cheated)
sprintf(status, "Auto-solver used. ");
else
*status = '\0';
sprintf(status + strlen(status), "Gems: %d", gems);
} else if (state->cheated) {
sprintf(status, "Auto-solved.");
} else {
sprintf(status, "COMPLETED!");
}
/* We subtract one from the visible death counter if we're still
* animating the move at the end of which the death took place. */
deaths = ui->deaths;
if (oldstate && ui->just_died) {
assert(deaths > 0);
deaths--;
}
if (deaths)
sprintf(status + strlen(status), " Deaths: %d", deaths);
status_bar(dr, status);
/*
* Draw the player sprite.
*/
assert(!ds->player_bg_saved);
assert(ds->player_background);
{
int ox, oy, nx, ny;
nx = COORD(state->px);
ny = COORD(state->py);
if (oldstate) {
ox = COORD(oldstate->px);
oy = COORD(oldstate->py);
} else {
ox = nx;
oy = ny;
}
ds->pbgx = ox + ap * (nx - ox);
ds->pbgy = oy + ap * (ny - oy);
}
blitter_save(dr, ds->player_background, ds->pbgx, ds->pbgy);
draw_player(dr, ds, ds->pbgx, ds->pbgy,
(state->dead && !oldstate),
(!oldstate && state->soln ?
state->soln->list[state->solnpos] : -1));
ds->player_bg_saved = true;
}
static float game_anim_length(const game_state *oldstate,
const game_state *newstate, int dir, game_ui *ui)
{
int dist;
if (dir > 0)
dist = newstate->distance_moved;
else
dist = oldstate->distance_moved;
ui->anim_length = sqrt(dist) * BASE_ANIM_LENGTH;
return ui->anim_length;
}
static float game_flash_length(const game_state *oldstate,
const game_state *newstate, int dir, game_ui *ui)
{
if (!oldstate->dead && newstate->dead) {
ui->flashtype = FLASH_DEAD;
return FLASH_LENGTH;
} else if (oldstate->gems && !newstate->gems) {
ui->flashtype = FLASH_WIN;
return FLASH_LENGTH;
}
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)
{
*x = ds->pbgx;
*y = ds->pbgy;
*w = *h = TILESIZE;
}
static int game_status(const game_state *state)
{
/*
* We never report the game as lost, on the grounds that if the
* player has died they're quite likely to want to undo and carry
* on.
*/
return state->gems == 0 ? +1 : 0;
}
#ifdef COMBINED
#define thegame inertia
#endif
const struct game thegame = {
"Inertia", "games.inertia", "inertia",
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,
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, NULL, NULL, /* print_size, print */
true, /* wants_statusbar */
false, NULL, /* timing_state */
0, /* flags */
};