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Solve function for Inertia, using what's essentially an approximate

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TSP algorithm.

[originally from svn r6289]
This commit is contained in:
Simon Tatham
2005-09-11 12:40:49 +00:00
parent 08c8cf370e
commit b25fcc3f26
2 changed files with 853 additions and 9 deletions
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850
inertia.c
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@ -32,6 +32,7 @@
#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) )
@ -56,6 +57,7 @@ enum {
COL_MINE,
COL_GEM,
COL_WALL,
COL_HINT,
NCOLOURS
};
@ -63,6 +65,12 @@ 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;
@ -70,6 +78,9 @@ struct game_state {
char *grid;
int distance_moved;
int dead;
int cheated;
int solnpos;
soln *soln;
};
static game_params *default_params(void)
@ -627,6 +638,10 @@ static game_state *new_game(midend *me, game_params *params, char *desc)
state->distance_moved = 0;
state->dead = FALSE;
state->cheated = FALSE;
state->solnpos = 0;
state->soln = NULL;
return state;
}
@ -643,20 +658,750 @@ static game_state *dup_game(game_state *state)
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(game_state *state, game_state *currstate,
char *aux, char **error)
{
return NULL;
int w = state->p.w, h = state->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;
char *err, *soln, *p;
/*
* 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;
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 = 0; i < circuitlen; i++) {
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 k, dest, ni, ti, thisdist;
#ifdef TSP_DIAGNOSTICS
printf("optimising section from %d - %d\n", j, i);
#endif
for (k = 0; k < n; k++)
dist[k] = -1;
head = tail = 0;
dist[circuit[j]] = 0;
list[tail++] = circuit[j];
while (head < tail && dist[circuit[i]] < 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[i]];
assert(thisdist >= 0 && thisdist <= i-j);
memmove(circuit+j+thisdist, circuit+i,
(circuitlen - i) * sizeof(int));
circuitlen -= i-j;
i = j + thisdist;
circuitlen += i-j;
#ifdef TSP_DIAGNOSTICS
printf("new section runs from %d - %d\n", j, i);
#endif
dest = i;
assert(dest >= 0);
ni = circuit[i];
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 (++j < i) {
int xy = nodes[circuit[j]] / DP1;
if (currstate->grid[xy] == GEM)
unvisited[xy]++;
}
#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 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 char *game_text_format(game_state *state)
@ -785,6 +1530,8 @@ static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds,
dir = 1;
else if (button == (MOD_NUM_KEYPAD | '3'))
dir = 3;
else if (button == ' ' && state->soln && state->solnpos < state->soln->len)
dir = state->soln->list[state->solnpos];
if (dir < 0)
return NULL;
@ -814,9 +1561,33 @@ static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds,
static game_state *execute_move(game_state *state, char *move)
{
int w = state->p.w, h = state->p.h /*, wh = w*h */;
int dir = atoi(move);
int dir;
game_state *ret;
if (*move == 'S') {
int len, i;
soln *sol;
/*
* This is a solve move, so we don't actually _change_ the
* grid but merely set up a stored solution path.
*/
move++;
len = strlen(move);
sol = snew(soln);
sol->len = len;
sol->list = snewn(len, unsigned char);
for (i = 0; i < len; i++)
sol->list[i] = move[i] - '0';
ret = dup_game(state);
ret->cheated = TRUE;
ret->soln = sol;
ret->solnpos = 0;
sol->refcount = 1;
return ret;
}
dir = atoi(move);
if (dir < 0 || dir >= DIRECTIONS)
return NULL; /* huh? */
@ -852,6 +1623,26 @@ static game_state *execute_move(game_state *state, char *move)
break;
}
if (ret->soln) {
/*
* If this move is the correct next one in the stored
* solution path, advance solnpos.
*/
if (ret->soln->list[ret->solnpos] == dir &&
ret->solnpos+1 < ret->soln->len) {
ret->solnpos++;
} else {
/*
* Otherwise, the user has strayed from the path, so
* the path is no longer valid.
*/
ret->soln->refcount--;
assert(ret->soln->refcount > 0);/* `state' at least still exists */
ret->soln = NULL;
ret->solnpos = 0;
}
}
return ret;
}
@ -913,6 +1704,10 @@ static float *game_colours(frontend *fe, game_state *state, int *ncolours)
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;
}
@ -949,7 +1744,7 @@ static void game_free_drawstate(drawing *dr, game_drawstate *ds)
}
static void draw_player(drawing *dr, game_drawstate *ds, int x, int y,
int dead)
int dead, int hintdir)
{
if (dead) {
int coords[DIRECTIONS*4];
@ -979,6 +1774,33 @@ static void draw_player(drawing *dr, game_drawstate *ds, int x, int y,
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);
}
@ -1204,12 +2026,19 @@ static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate,
* shown between the collection of the last gem and the
* completion of the move animation that did it.)
*/
if (state->dead && (!oldstate || oldstate->dead))
if (state->dead && (!oldstate || oldstate->dead)) {
sprintf(status, "DEAD!");
else if (state->gems || (oldstate && oldstate->gems))
sprintf(status, "Gems: %d", gems);
else
} 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;
@ -1241,7 +2070,10 @@ static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate,
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));
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;
}
@ -1307,7 +2139,7 @@ const struct game thegame = {
new_game,
dup_game,
free_game,
FALSE, solve_game,
TRUE, solve_game,
FALSE, game_text_format,
new_ui,
free_ui,