2 * inertia.c: Game involving navigating round a grid picking up
5 * Game rules and basic generator design by Ben Olmstead.
6 * This re-implementation was written by Simon Tatham.
18 /* Used in the game_state */
25 /* Used in the game IDs */
28 /* Used in the game generation */
31 /* Used only in the game_drawstate*/
35 #define DP1 (DIRECTIONS+1)
36 #define DX(dir) ( (dir) & 3 ? (((dir) & 7) > 4 ? -1 : +1) : 0 )
37 #define DY(dir) ( DX((dir)+6) )
40 * Lvalue macro which expects x and y to be in range.
42 #define LV_AT(w, h, grid, x, y) ( (grid)[(y)*(w)+(x)] )
45 * Rvalue macro which can cope with x and y being out of range.
47 #define AT(w, h, grid, x, y) ( (x)<0 || (x)>=(w) || (y)<0 || (y)>=(h) ? \
48 WALL : LV_AT(w, h, grid, x, y) )
86 static game_params *default_params(void)
88 game_params *ret = snew(game_params);
91 #ifdef PORTRAIT_SCREEN
99 static void free_params(game_params *params)
104 static game_params *dup_params(const game_params *params)
106 game_params *ret = snew(game_params);
107 *ret = *params; /* structure copy */
111 static const struct game_params inertia_presets[] = {
112 #ifdef PORTRAIT_SCREEN
123 static int game_fetch_preset(int i, char **name, game_params **params)
129 if (i < 0 || i >= lenof(inertia_presets))
132 p = inertia_presets[i];
133 ret = dup_params(&p);
134 sprintf(namebuf, "%dx%d", ret->w, ret->h);
135 retname = dupstr(namebuf);
142 static void decode_params(game_params *params, char const *string)
144 params->w = params->h = atoi(string);
145 while (*string && isdigit((unsigned char)*string)) string++;
146 if (*string == 'x') {
148 params->h = atoi(string);
152 static char *encode_params(const game_params *params, int full)
156 sprintf(data, "%dx%d", params->w, params->h);
161 static config_item *game_configure(const game_params *params)
166 ret = snewn(3, config_item);
168 ret[0].name = "Width";
169 ret[0].type = C_STRING;
170 sprintf(buf, "%d", params->w);
171 ret[0].u.string.sval = dupstr(buf);
173 ret[1].name = "Height";
174 ret[1].type = C_STRING;
175 sprintf(buf, "%d", params->h);
176 ret[1].u.string.sval = dupstr(buf);
184 static game_params *custom_params(const config_item *cfg)
186 game_params *ret = snew(game_params);
188 ret->w = atoi(cfg[0].u.string.sval);
189 ret->h = atoi(cfg[1].u.string.sval);
194 static const char *validate_params(const game_params *params, int full)
197 * Avoid completely degenerate cases which only have one
198 * row/column. We probably could generate completable puzzles
199 * of that shape, but they'd be forced to be extremely boring
200 * and at large sizes would take a while to happen upon at
203 if (params->w < 2 || params->h < 2)
204 return "Width and height must both be at least two";
207 * The grid construction algorithm creates 1/5 as many gems as
208 * grid squares, and must create at least one gem to have an
209 * actual puzzle. However, an area-five grid is ruled out by
210 * the above constraint, so the practical minimum is six.
212 if (params->w * params->h < 6)
213 return "Grid area must be at least six squares";
218 /* ----------------------------------------------------------------------
219 * Solver used by grid generator.
222 struct solver_scratch {
223 unsigned char *reachable_from, *reachable_to;
227 static struct solver_scratch *new_scratch(int w, int h)
229 struct solver_scratch *sc = snew(struct solver_scratch);
231 sc->reachable_from = snewn(w * h * DIRECTIONS, unsigned char);
232 sc->reachable_to = snewn(w * h * DIRECTIONS, unsigned char);
233 sc->positions = snewn(w * h * DIRECTIONS, int);
238 static void free_scratch(struct solver_scratch *sc)
240 sfree(sc->reachable_from);
241 sfree(sc->reachable_to);
242 sfree(sc->positions);
246 static int can_go(int w, int h, char *grid,
247 int x1, int y1, int dir1, int x2, int y2, int dir2)
250 * Returns TRUE if we can transition directly from (x1,y1)
251 * going in direction dir1, to (x2,y2) going in direction dir2.
255 * If we're actually in the middle of an unoccupyable square,
256 * we cannot make any move.
258 if (AT(w, h, grid, x1, y1) == WALL ||
259 AT(w, h, grid, x1, y1) == MINE)
263 * If a move is capable of stopping at x1,y1,dir1, and x2,y2 is
264 * the same coordinate as x1,y1, then we can make the
265 * transition (by stopping and changing direction).
267 * For this to be the case, we have to either have a wall
268 * beyond x1,y1,dir1, or have a stop on x1,y1.
270 if (x2 == x1 && y2 == y1 &&
271 (AT(w, h, grid, x1, y1) == STOP ||
272 AT(w, h, grid, x1, y1) == START ||
273 AT(w, h, grid, x1+DX(dir1), y1+DY(dir1)) == WALL))
277 * If a move is capable of continuing here, then x1,y1,dir1 can
278 * move one space further on.
280 if (x2 == x1+DX(dir1) && y2 == y1+DY(dir1) && dir1 == dir2 &&
281 (AT(w, h, grid, x2, y2) == BLANK ||
282 AT(w, h, grid, x2, y2) == GEM ||
283 AT(w, h, grid, x2, y2) == STOP ||
284 AT(w, h, grid, x2, y2) == START))
293 static int find_gem_candidates(int w, int h, char *grid,
294 struct solver_scratch *sc)
298 int sx, sy, gx, gy, gd, pass, possgems;
301 * This function finds all the candidate gem squares, which are
302 * precisely those squares which can be picked up on a loop
303 * from the starting point back to the starting point. Doing
304 * this may involve passing through such a square in the middle
305 * of a move; so simple breadth-first search over the _squares_
306 * of the grid isn't quite adequate, because it might be that
307 * we can only reach a gem from the start by moving over it in
308 * one direction, but can only return to the start if we were
309 * moving over it in another direction.
311 * Instead, we BFS over a space which mentions each grid square
312 * eight times - once for each direction. We also BFS twice:
313 * once to find out what square+direction pairs we can reach
314 * _from_ the start point, and once to find out what pairs we
315 * can reach the start point from. Then a square is reachable
316 * if any of the eight directions for that square has both
320 memset(sc->reachable_from, 0, wh * DIRECTIONS);
321 memset(sc->reachable_to, 0, wh * DIRECTIONS);
324 * Find the starting square.
326 sx = -1; /* placate optimiser */
327 for (sy = 0; sy < h; sy++) {
328 for (sx = 0; sx < w; sx++)
329 if (AT(w, h, grid, sx, sy) == START)
336 for (pass = 0; pass < 2; pass++) {
337 unsigned char *reachable = (pass == 0 ? sc->reachable_from :
339 int sign = (pass == 0 ? +1 : -1);
342 #ifdef SOLVER_DIAGNOSTICS
343 printf("starting pass %d\n", pass);
347 * `head' and `tail' are indices within sc->positions which
348 * track the list of board positions left to process.
351 for (dir = 0; dir < DIRECTIONS; dir++) {
352 int index = (sy*w+sx)*DIRECTIONS+dir;
353 sc->positions[tail++] = index;
354 reachable[index] = TRUE;
355 #ifdef SOLVER_DIAGNOSTICS
356 printf("starting point %d,%d,%d\n", sx, sy, dir);
361 * Now repeatedly pick an element off the list and process
364 while (head < tail) {
365 int index = sc->positions[head++];
366 int dir = index % DIRECTIONS;
367 int x = (index / DIRECTIONS) % w;
368 int y = index / (w * DIRECTIONS);
369 int n, x2, y2, d2, i2;
371 #ifdef SOLVER_DIAGNOSTICS
372 printf("processing point %d,%d,%d\n", x, y, dir);
375 * The places we attempt to switch to here are:
376 * - each possible direction change (all the other
377 * directions in this square)
378 * - one step further in the direction we're going (or
379 * one step back, if we're in the reachable_to pass).
381 for (n = -1; n < DIRECTIONS; n++) {
383 x2 = x + sign * DX(dir);
384 y2 = y + sign * DY(dir);
391 i2 = (y2*w+x2)*DIRECTIONS+d2;
392 if (x2 >= 0 && x2 < w &&
396 #ifdef SOLVER_DIAGNOSTICS
397 printf(" trying point %d,%d,%d", x2, y2, d2);
400 ok = can_go(w, h, grid, x, y, dir, x2, y2, d2);
402 ok = can_go(w, h, grid, x2, y2, d2, x, y, dir);
403 #ifdef SOLVER_DIAGNOSTICS
404 printf(" - %sok\n", ok ? "" : "not ");
407 sc->positions[tail++] = i2;
408 reachable[i2] = TRUE;
416 * And that should be it. Now all we have to do is find the
417 * squares for which there exists _some_ direction such that
418 * the square plus that direction form a tuple which is both
419 * reachable from the start and reachable to the start.
422 for (gy = 0; gy < h; gy++)
423 for (gx = 0; gx < w; gx++)
424 if (AT(w, h, grid, gx, gy) == BLANK) {
425 for (gd = 0; gd < DIRECTIONS; gd++) {
426 int index = (gy*w+gx)*DIRECTIONS+gd;
427 if (sc->reachable_from[index] && sc->reachable_to[index]) {
428 #ifdef SOLVER_DIAGNOSTICS
429 printf("space at %d,%d is reachable via"
430 " direction %d\n", gx, gy, gd);
432 LV_AT(w, h, grid, gx, gy) = POSSGEM;
442 /* ----------------------------------------------------------------------
443 * Grid generation code.
446 static char *gengrid(int w, int h, random_state *rs)
449 char *grid = snewn(wh+1, char);
450 struct solver_scratch *sc = new_scratch(w, h);
451 int maxdist_threshold, tries;
453 maxdist_threshold = 2;
459 int *dist, *list, head, tail, maxdist;
462 * We're going to fill the grid with the five basic piece
463 * types in about 1/5 proportion. For the moment, though,
464 * we leave out the gems, because we'll put those in
465 * _after_ we run the solver to tell us where the viable
469 for (j = 0; j < wh/5; j++)
471 for (j = 0; j < wh/5; j++)
473 for (j = 0; j < wh/5; j++)
479 shuffle(grid, wh, sizeof(*grid), rs);
482 * Find the viable gem locations, and immediately give up
483 * and try again if there aren't enough of them.
485 possgems = find_gem_candidates(w, h, grid, sc);
490 * We _could_ now select wh/5 of the POSSGEMs and set them
491 * to GEM, and have a viable level. However, there's a
492 * chance that a large chunk of the level will turn out to
493 * be unreachable, so first we test for that.
495 * We do this by finding the largest distance from any
496 * square to the nearest POSSGEM, by breadth-first search.
497 * If this is above a critical threshold, we abort and try
500 * (This search is purely geometric, without regard to
501 * walls and long ways round.)
503 dist = sc->positions;
504 list = sc->positions + wh;
505 for (i = 0; i < wh; i++)
508 for (i = 0; i < wh; i++)
509 if (grid[i] == POSSGEM) {
514 while (head < tail) {
518 if (maxdist < dist[pos])
524 for (d = 0; d < DIRECTIONS; d++) {
530 if (x2 >= 0 && x2 < w && y2 >= 0 && y2 < h) {
533 dist[p2] = dist[pos] + 1;
539 assert(head == wh && tail == wh);
542 * Now abandon this grid and go round again if maxdist is
543 * above the required threshold.
545 * We can safely start the threshold as low as 2. As we
546 * accumulate failed generation attempts, we gradually
547 * raise it as we get more desperate.
549 if (maxdist > maxdist_threshold) {
559 * Now our reachable squares are plausibly evenly
560 * distributed over the grid. I'm not actually going to
561 * _enforce_ that I place the gems in such a way as not to
562 * increase that maxdist value; I'm now just going to trust
563 * to the RNG to pick a sensible subset of the POSSGEMs.
566 for (i = 0; i < wh; i++)
567 if (grid[i] == POSSGEM)
569 shuffle(list, j, sizeof(*list), rs);
570 for (i = 0; i < j; i++)
571 grid[list[i]] = (i < wh/5 ? GEM : BLANK);
582 static char *new_game_desc(const game_params *params, random_state *rs,
583 char **aux, int interactive)
585 return gengrid(params->w, params->h, rs);
588 static const char *validate_desc(const game_params *params, const char *desc)
590 int w = params->w, h = params->h, wh = w*h;
591 int starts = 0, gems = 0, i;
593 for (i = 0; i < wh; i++) {
595 return "Not enough data to fill grid";
596 if (desc[i] != WALL && desc[i] != START && desc[i] != STOP &&
597 desc[i] != GEM && desc[i] != MINE && desc[i] != BLANK)
598 return "Unrecognised character in game description";
599 if (desc[i] == START)
605 return "Too much data to fill grid";
607 return "No starting square specified";
609 return "More than one starting square specified";
611 return "No gems specified";
616 static game_state *new_game(midend *me, const game_params *params,
619 int w = params->w, h = params->h, wh = w*h;
621 game_state *state = snew(game_state);
623 state->p = *params; /* structure copy */
625 state->grid = snewn(wh, char);
626 assert(strlen(desc) == wh);
627 memcpy(state->grid, desc, wh);
629 state->px = state->py = -1;
631 for (i = 0; i < wh; i++) {
632 if (state->grid[i] == START) {
633 state->grid[i] = STOP;
636 } else if (state->grid[i] == GEM) {
641 assert(state->gems > 0);
642 assert(state->px >= 0 && state->py >= 0);
644 state->distance_moved = 0;
647 state->cheated = FALSE;
654 static game_state *dup_game(const game_state *state)
656 int w = state->p.w, h = state->p.h, wh = w*h;
657 game_state *ret = snew(game_state);
662 ret->gems = state->gems;
663 ret->grid = snewn(wh, char);
664 ret->distance_moved = state->distance_moved;
666 memcpy(ret->grid, state->grid, wh);
667 ret->cheated = state->cheated;
668 ret->soln = state->soln;
670 ret->soln->refcount++;
671 ret->solnpos = state->solnpos;
676 static void free_game(game_state *state)
678 if (state->soln && --state->soln->refcount == 0) {
679 sfree(state->soln->list);
687 * Internal function used by solver.
689 static int move_goes_to(int w, int h, char *grid, int x, int y, int d)
694 * See where we'd get to if we made this move.
696 dr = -1; /* placate optimiser */
698 if (AT(w, h, grid, x+DX(d), y+DY(d)) == WALL) {
699 dr = DIRECTIONS; /* hit a wall, so end up stationary */
704 if (AT(w, h, grid, x, y) == STOP) {
705 dr = DIRECTIONS; /* hit a stop, so end up stationary */
708 if (AT(w, h, grid, x, y) == GEM) {
709 dr = d; /* hit a gem, so we're still moving */
712 if (AT(w, h, grid, x, y) == MINE)
713 return -1; /* hit a mine, so move is invalid */
716 return (y*w+x)*DP1+dr;
719 static int compare_integers(const void *av, const void *bv)
721 const int *a = (const int *)av;
722 const int *b = (const int *)bv;
731 static char *solve_game(const game_state *state, const game_state *currstate,
732 const char *aux, const char **error)
734 int w = currstate->p.w, h = currstate->p.h, wh = w*h;
735 int *nodes, *nodeindex, *edges, *backedges, *edgei, *backedgei, *circuit;
737 int *dist, *dist2, *list;
739 int circuitlen, circuitsize;
740 int head, tail, pass, i, j, n, x, y, d, dd;
745 * Before anything else, deal with the special case in which
746 * all the gems are already collected.
748 for (i = 0; i < wh; i++)
749 if (currstate->grid[i] == GEM)
752 *error = "Game is already solved";
757 * Solving Inertia is a question of first building up the graph
758 * of where you can get to from where, and secondly finding a
759 * tour of the graph which takes in every gem.
761 * This is of course a close cousin of the travelling salesman
762 * problem, which is NP-complete; so I rather doubt that any
763 * _optimal_ tour can be found in plausible time. Hence I'll
764 * restrict myself to merely finding a not-too-bad one.
766 * First construct the graph, by bfsing out move by move from
767 * the current player position. Graph vertices will be
768 * - every endpoint of a move (place the ball can be
770 * - every gem (place the ball can go through in motion).
771 * Vertices of this type have an associated direction, since
772 * if a gem can be collected by sliding through it in two
773 * different directions it doesn't follow that you can
774 * change direction at it.
776 * I'm going to refer to a non-directional vertex as
777 * (y*w+x)*DP1+DIRECTIONS, and a directional one as
782 * nodeindex[] maps node codes as shown above to numeric
783 * indices in the nodes[] array.
785 nodeindex = snewn(DP1*wh, int);
786 for (i = 0; i < DP1*wh; i++)
790 * Do the bfs to find all the interesting graph nodes.
792 nodes = snewn(DP1*wh, int);
795 nodes[tail] = (currstate->py * w + currstate->px) * DP1 + DIRECTIONS;
796 nodeindex[nodes[0]] = tail;
799 while (head < tail) {
800 int nc = nodes[head++], nnc;
805 * Plot all possible moves from this node. If the node is
806 * directed, there's only one.
808 for (dd = 0; dd < DIRECTIONS; dd++) {
813 if (d < DIRECTIONS && d != dd)
816 nnc = move_goes_to(w, h, currstate->grid, x, y, dd);
817 if (nnc >= 0 && nnc != nc) {
818 if (nodeindex[nnc] < 0) {
820 nodeindex[nnc] = tail;
829 * Now we know how many nodes we have, allocate the edge array
830 * and go through setting up the edges.
832 edges = snewn(DIRECTIONS*n, int);
833 edgei = snewn(n+1, int);
836 for (i = 0; i < n; i++) {
846 for (dd = 0; dd < DIRECTIONS; dd++) {
849 if (d >= DIRECTIONS || d == dd) {
850 nnc = move_goes_to(w, h, currstate->grid, x, y, dd);
852 if (nnc >= 0 && nnc != nc)
853 edges[nedges++] = nodeindex[nnc];
860 * Now set up the backedges array.
862 backedges = snewn(nedges, int);
863 backedgei = snewn(n+1, int);
864 for (i = j = 0; i < nedges; i++) {
865 while (j+1 < n && i >= edgei[j+1])
867 backedges[i] = edges[i] * n + j;
869 qsort(backedges, nedges, sizeof(int), compare_integers);
871 for (i = j = 0; i < nedges; i++) {
872 int k = backedges[i] / n;
877 backedgei[n] = nedges;
880 * Set up the initial tour. At all times, our tour is a circuit
881 * of graph vertices (which may, and probably will often,
882 * repeat vertices). To begin with, it's got exactly one vertex
883 * in it, which is the player's current starting point.
886 circuit = snewn(circuitsize, int);
888 circuit[circuitlen++] = 0; /* node index 0 is the starting posn */
891 * Track which gems are as yet unvisited.
893 unvisited = snewn(wh, int);
894 for (i = 0; i < wh; i++)
895 unvisited[i] = FALSE;
896 for (i = 0; i < wh; i++)
897 if (currstate->grid[i] == GEM)
901 * Allocate space for doing bfses inside the main loop.
903 dist = snewn(n, int);
904 dist2 = snewn(n, int);
905 list = snewn(n, int);
911 * Now enter the main loop, in each iteration of which we
912 * extend the tour to take in an as yet uncollected gem.
915 int target, n1, n2, bestdist, extralen, targetpos;
917 #ifdef TSP_DIAGNOSTICS
918 printf("circuit is");
919 for (i = 0; i < circuitlen; i++) {
920 int nc = nodes[circuit[i]];
921 printf(" (%d,%d,%d)", nc/DP1%w, nc/(DP1*w), nc%DP1);
924 printf("moves are ");
925 x = nodes[circuit[0]] / DP1 % w;
926 y = nodes[circuit[0]] / DP1 / w;
927 for (i = 1; i < circuitlen; i++) {
929 if (nodes[circuit[i]] % DP1 != DIRECTIONS)
931 x2 = nodes[circuit[i]] / DP1 % w;
932 y2 = nodes[circuit[i]] / DP1 / w;
933 dx = (x2 > x ? +1 : x2 < x ? -1 : 0);
934 dy = (y2 > y ? +1 : y2 < y ? -1 : 0);
935 for (d = 0; d < DIRECTIONS; d++)
936 if (DX(d) == dx && DY(d) == dy)
937 printf("%c", "89632147"[d]);
945 * First, start a pair of bfses at _every_ vertex currently
946 * in the tour, and extend them outwards to find the
947 * nearest as yet unreached gem vertex.
949 * This is largely a heuristic: we could pick _any_ doubly
950 * reachable node here and still get a valid tour as
951 * output. I hope that picking a nearby one will result in
952 * generally good tours.
954 for (pass = 0; pass < 2; pass++) {
955 int *ep = (pass == 0 ? edges : backedges);
956 int *ei = (pass == 0 ? edgei : backedgei);
957 int *dp = (pass == 0 ? dist : dist2);
959 for (i = 0; i < n; i++)
961 for (i = 0; i < circuitlen; i++) {
968 while (head < tail) {
969 int ni = list[head++];
970 for (i = ei[ni]; i < ei[ni+1]; i++) {
972 if (ti >= 0 && dp[ti] < 0) {
979 /* Now find the nearest unvisited gem. */
982 for (i = 0; i < n; i++) {
983 if (unvisited[nodes[i] / DP1] &&
984 dist[i] >= 0 && dist2[i] >= 0) {
985 int thisdist = dist[i] + dist2[i];
986 if (bestdist < 0 || bestdist > thisdist) {
995 * If we get to here, we haven't found a gem we can get
996 * at all, which means we terminate this loop.
1002 * Now we have a graph vertex at list[tail-1] which is an
1003 * unvisited gem. We want to add that vertex to our tour.
1004 * So we run two more breadth-first searches: one starting
1005 * from that vertex and following forward edges, and
1006 * another starting from the same vertex and following
1007 * backward edges. This allows us to determine, for each
1008 * node on the current tour, how quickly we can get both to
1009 * and from the target vertex from that node.
1011 #ifdef TSP_DIAGNOSTICS
1012 printf("target node is %d (%d,%d,%d)\n", target, nodes[target]/DP1%w,
1013 nodes[target]/DP1/w, nodes[target]%DP1);
1016 for (pass = 0; pass < 2; pass++) {
1017 int *ep = (pass == 0 ? edges : backedges);
1018 int *ei = (pass == 0 ? edgei : backedgei);
1019 int *dp = (pass == 0 ? dist : dist2);
1021 for (i = 0; i < n; i++)
1026 list[tail++] = target;
1028 while (head < tail) {
1029 int ni = list[head++];
1030 for (i = ei[ni]; i < ei[ni+1]; i++) {
1032 if (ti >= 0 && dp[ti] < 0) {
1033 dp[ti] = dp[ni] + 1;
1034 /*printf("pass %d: set dist of vertex %d to %d (via %d)\n", pass, ti, dp[ti], ni);*/
1042 * Now for every node n, dist[n] gives the length of the
1043 * shortest path from the target vertex to n, and dist2[n]
1044 * gives the length of the shortest path from n to the
1047 * Our next step is to search linearly along the tour to
1048 * find the optimum place to insert a trip to the target
1049 * vertex and back. Our two options are either
1050 * (a) to find two adjacent vertices A,B in the tour and
1051 * replace the edge A->B with the path A->target->B
1052 * (b) to find a single vertex X in the tour and replace
1053 * it with the complete round trip X->target->X.
1054 * We do whichever takes the fewest moves.
1058 for (i = 0; i < circuitlen; i++) {
1062 * Try a round trip from vertex i.
1064 if (dist[circuit[i]] >= 0 &&
1065 dist2[circuit[i]] >= 0) {
1066 thisdist = dist[circuit[i]] + dist2[circuit[i]];
1067 if (bestdist < 0 || thisdist < bestdist) {
1068 bestdist = thisdist;
1074 * Try a trip from vertex i via target to vertex i+1.
1076 if (i+1 < circuitlen &&
1077 dist2[circuit[i]] >= 0 &&
1078 dist[circuit[i+1]] >= 0) {
1079 thisdist = dist2[circuit[i]] + dist[circuit[i+1]];
1080 if (bestdist < 0 || thisdist < bestdist) {
1081 bestdist = thisdist;
1089 * We couldn't find a round trip taking in this gem _at
1092 err = "Unable to find a solution from this starting point";
1095 #ifdef TSP_DIAGNOSTICS
1096 printf("insertion point: n1=%d, n2=%d, dist=%d\n", n1, n2, bestdist);
1099 #ifdef TSP_DIAGNOSTICS
1100 printf("circuit before lengthening is");
1101 for (i = 0; i < circuitlen; i++) {
1102 printf(" %d", circuit[i]);
1108 * Now actually lengthen the tour to take in this round
1111 extralen = dist2[circuit[n1]] + dist[circuit[n2]];
1114 circuitlen += extralen;
1115 if (circuitlen >= circuitsize) {
1116 circuitsize = circuitlen + 256;
1117 circuit = sresize(circuit, circuitsize, int);
1119 memmove(circuit + n2 + extralen, circuit + n2,
1120 (circuitlen - n2 - extralen) * sizeof(int));
1123 #ifdef TSP_DIAGNOSTICS
1124 printf("circuit in middle of lengthening is");
1125 for (i = 0; i < circuitlen; i++) {
1126 printf(" %d", circuit[i]);
1132 * Find the shortest-path routes to and from the target,
1133 * and write them into the circuit.
1135 targetpos = n1 + dist2[circuit[n1]];
1136 assert(targetpos - dist2[circuit[n1]] == n1);
1137 assert(targetpos + dist[circuit[n2]] == n2);
1138 for (pass = 0; pass < 2; pass++) {
1139 int dir = (pass == 0 ? -1 : +1);
1140 int *ep = (pass == 0 ? backedges : edges);
1141 int *ei = (pass == 0 ? backedgei : edgei);
1142 int *dp = (pass == 0 ? dist : dist2);
1143 int nn = (pass == 0 ? n2 : n1);
1144 int ni = circuit[nn], ti, dest = nn;
1152 /*printf("pass %d: looking at vertex %d\n", pass, ni);*/
1153 for (i = ei[ni]; i < ei[ni+1]; i++) {
1155 if (ti >= 0 && dp[ti] == dp[ni] - 1)
1158 assert(i < ei[ni+1] && ti >= 0);
1163 #ifdef TSP_DIAGNOSTICS
1164 printf("circuit after lengthening is");
1165 for (i = 0; i < circuitlen; i++) {
1166 printf(" %d", circuit[i]);
1172 * Finally, mark all gems that the new piece of circuit
1173 * passes through as visited.
1175 for (i = n1; i <= n2; i++) {
1176 int pos = nodes[circuit[i]] / DP1;
1177 assert(pos >= 0 && pos < wh);
1178 unvisited[pos] = FALSE;
1182 #ifdef TSP_DIAGNOSTICS
1183 printf("before reduction, moves are ");
1184 x = nodes[circuit[0]] / DP1 % w;
1185 y = nodes[circuit[0]] / DP1 / w;
1186 for (i = 1; i < circuitlen; i++) {
1188 if (nodes[circuit[i]] % DP1 != DIRECTIONS)
1190 x2 = nodes[circuit[i]] / DP1 % w;
1191 y2 = nodes[circuit[i]] / DP1 / w;
1192 dx = (x2 > x ? +1 : x2 < x ? -1 : 0);
1193 dy = (y2 > y ? +1 : y2 < y ? -1 : 0);
1194 for (d = 0; d < DIRECTIONS; d++)
1195 if (DX(d) == dx && DY(d) == dy)
1196 printf("%c", "89632147"[d]);
1204 * That's got a basic solution. Now optimise it by removing
1205 * redundant sections of the circuit: it's entirely possible
1206 * that a piece of circuit we carefully inserted at one stage
1207 * to collect a gem has become pointless because the steps
1208 * required to collect some _later_ gem necessarily passed
1209 * through the same one.
1211 * So first we go through and work out how many times each gem
1212 * is collected. Then we look for maximal sections of circuit
1213 * which are redundant in the sense that their removal would
1214 * not reduce any gem's collection count to zero, and replace
1215 * each one with a bfs-derived fastest path between their
1219 int oldlen = circuitlen;
1222 for (dir = +1; dir >= -1; dir -= 2) {
1224 for (i = 0; i < wh; i++)
1226 for (i = 0; i < circuitlen; i++) {
1227 int xy = nodes[circuit[i]] / DP1;
1228 if (currstate->grid[xy] == GEM)
1233 * If there's any gem we didn't end up visiting at all,
1236 for (i = 0; i < wh; i++) {
1237 if (currstate->grid[i] == GEM && unvisited[i] == 0) {
1238 err = "Unable to find a solution from this starting point";
1245 for (i = j = (dir > 0 ? 0 : circuitlen-1);
1246 i < circuitlen && i >= 0;
1248 int xy = nodes[circuit[i]] / DP1;
1249 if (currstate->grid[xy] == GEM && unvisited[xy] > 1) {
1251 } else if (currstate->grid[xy] == GEM || i == circuitlen-1) {
1253 * circuit[i] collects a gem for the only time,
1254 * or is the last node in the circuit.
1255 * Therefore it cannot be removed; so we now
1256 * want to replace the path from circuit[j] to
1257 * circuit[i] with a bfs-shortest path.
1259 int p, q, k, dest, ni, ti, thisdist;
1262 * Set up the upper and lower bounds of the
1268 #ifdef TSP_DIAGNOSTICS
1269 printf("optimising section from %d - %d\n", p, q);
1272 for (k = 0; k < n; k++)
1276 dist[circuit[p]] = 0;
1277 list[tail++] = circuit[p];
1279 while (head < tail && dist[circuit[q]] < 0) {
1280 int ni = list[head++];
1281 for (k = edgei[ni]; k < edgei[ni+1]; k++) {
1283 if (ti >= 0 && dist[ti] < 0) {
1284 dist[ti] = dist[ni] + 1;
1290 thisdist = dist[circuit[q]];
1291 assert(thisdist >= 0 && thisdist <= q-p);
1293 memmove(circuit+p+thisdist, circuit+q,
1294 (circuitlen - q) * sizeof(int));
1300 i = q; /* resume loop from the right place */
1302 #ifdef TSP_DIAGNOSTICS
1303 printf("new section runs from %d - %d\n", p, q);
1311 /* printf("dest=%d circuitlen=%d ni=%d dist[ni]=%d\n", dest, circuitlen, ni, dist[ni]); */
1317 for (k = backedgei[ni]; k < backedgei[ni+1]; k++) {
1319 if (ti >= 0 && dist[ti] == dist[ni] - 1)
1322 assert(k < backedgei[ni+1] && ti >= 0);
1327 * Now re-increment the visit counts for the
1331 int xy = nodes[circuit[p]] / DP1;
1332 if (currstate->grid[xy] == GEM)
1338 #ifdef TSP_DIAGNOSTICS
1339 printf("during reduction, circuit is");
1340 for (k = 0; k < circuitlen; k++) {
1341 int nc = nodes[circuit[k]];
1342 printf(" (%d,%d,%d)", nc/DP1%w, nc/(DP1*w), nc%DP1);
1345 printf("moves are ");
1346 x = nodes[circuit[0]] / DP1 % w;
1347 y = nodes[circuit[0]] / DP1 / w;
1348 for (k = 1; k < circuitlen; k++) {
1350 if (nodes[circuit[k]] % DP1 != DIRECTIONS)
1352 x2 = nodes[circuit[k]] / DP1 % w;
1353 y2 = nodes[circuit[k]] / DP1 / w;
1354 dx = (x2 > x ? +1 : x2 < x ? -1 : 0);
1355 dy = (y2 > y ? +1 : y2 < y ? -1 : 0);
1356 for (d = 0; d < DIRECTIONS; d++)
1357 if (DX(d) == dx && DY(d) == dy)
1358 printf("%c", "89632147"[d]);
1367 #ifdef TSP_DIAGNOSTICS
1368 printf("after reduction, moves are ");
1369 x = nodes[circuit[0]] / DP1 % w;
1370 y = nodes[circuit[0]] / DP1 / w;
1371 for (i = 1; i < circuitlen; i++) {
1373 if (nodes[circuit[i]] % DP1 != DIRECTIONS)
1375 x2 = nodes[circuit[i]] / DP1 % w;
1376 y2 = nodes[circuit[i]] / DP1 / w;
1377 dx = (x2 > x ? +1 : x2 < x ? -1 : 0);
1378 dy = (y2 > y ? +1 : y2 < y ? -1 : 0);
1379 for (d = 0; d < DIRECTIONS; d++)
1380 if (DX(d) == dx && DY(d) == dy)
1381 printf("%c", "89632147"[d]);
1390 * If we've managed an entire reduction pass in each
1391 * direction and not made the solution any shorter, we're
1394 if (circuitlen == oldlen)
1399 * Encode the solution as a move string.
1402 soln = snewn(circuitlen+2, char);
1405 x = nodes[circuit[0]] / DP1 % w;
1406 y = nodes[circuit[0]] / DP1 / w;
1407 for (i = 1; i < circuitlen; i++) {
1409 if (nodes[circuit[i]] % DP1 != DIRECTIONS)
1411 x2 = nodes[circuit[i]] / DP1 % w;
1412 y2 = nodes[circuit[i]] / DP1 / w;
1413 dx = (x2 > x ? +1 : x2 < x ? -1 : 0);
1414 dy = (y2 > y ? +1 : y2 < y ? -1 : 0);
1415 for (d = 0; d < DIRECTIONS; d++)
1416 if (DX(d) == dx && DY(d) == dy) {
1420 assert(d < DIRECTIONS);
1425 assert(p - soln < circuitlen+2);
1446 static int game_can_format_as_text_now(const game_params *params)
1451 static char *game_text_format(const game_state *state)
1453 int w = state->p.w, h = state->p.h, r, c;
1454 int cw = 4, ch = 2, gw = cw*w + 2, gh = ch * h + 1, len = gw * gh;
1455 char *board = snewn(len + 1, char);
1457 sprintf(board, "%*s+\n", len - 2, "");
1459 for (r = 0; r < h; ++r) {
1460 for (c = 0; c < w; ++c) {
1461 int cell = r*ch*gw + cw*c, center = cell + gw*ch/2 + cw/2;
1463 switch (state->grid[i]) {
1465 case GEM: board[center] = 'o'; break;
1466 case MINE: board[center] = 'M'; break;
1467 case STOP: board[center-1] = '('; board[center+1] = ')'; break;
1468 case WALL: memset(board + center - 1, 'X', 3);
1471 if (r == state->py && c == state->px) {
1472 if (!state->dead) board[center] = '@';
1473 else memcpy(board + center - 1, ":-(", 3);
1476 memset(board + cell + 1, '-', cw - 1);
1477 for (i = 1; i < ch; ++i) board[cell + i*gw] = '|';
1479 for (c = 0; c < ch; ++c) {
1480 board[(r*ch+c)*gw + gw - 2] = "|+"[!c];
1481 board[(r*ch+c)*gw + gw - 1] = '\n';
1484 memset(board + len - gw, '-', gw - 2);
1485 for (c = 0; c < w; ++c) board[len - gw + cw*c] = '+';
1498 static game_ui *new_ui(const game_state *state)
1500 game_ui *ui = snew(game_ui);
1501 ui->anim_length = 0.0F;
1504 ui->just_made_move = FALSE;
1505 ui->just_died = FALSE;
1509 static void free_ui(game_ui *ui)
1514 static char *encode_ui(const game_ui *ui)
1518 * The deaths counter needs preserving across a serialisation.
1520 sprintf(buf, "D%d", ui->deaths);
1524 static void decode_ui(game_ui *ui, const char *encoding)
1527 sscanf(encoding, "D%d%n", &ui->deaths, &p);
1530 static void game_changed_state(game_ui *ui, const game_state *oldstate,
1531 const game_state *newstate)
1534 * Increment the deaths counter. We only do this if
1535 * ui->just_made_move is set (redoing a suicide move doesn't
1536 * kill you _again_), and also we only do it if the game wasn't
1537 * already completed (once you're finished, you can play).
1539 if (!oldstate->dead && newstate->dead && ui->just_made_move &&
1542 ui->just_died = TRUE;
1544 ui->just_died = FALSE;
1546 ui->just_made_move = FALSE;
1549 struct game_drawstate {
1553 unsigned short *grid;
1554 blitter *player_background;
1555 int player_bg_saved, pbgx, pbgy;
1558 #define PREFERRED_TILESIZE 32
1559 #define TILESIZE (ds->tilesize)
1561 #define BORDER (TILESIZE / 4)
1563 #define BORDER (TILESIZE)
1565 #define HIGHLIGHT_WIDTH (TILESIZE / 10)
1566 #define COORD(x) ( (x) * TILESIZE + BORDER )
1567 #define FROMCOORD(x) ( ((x) - BORDER + TILESIZE) / TILESIZE - 1 )
1569 static char *interpret_move(const game_state *state, game_ui *ui,
1570 const game_drawstate *ds,
1571 int x, int y, int button)
1573 int w = state->p.w, h = state->p.h /*, wh = w*h */;
1579 if (button == LEFT_BUTTON) {
1581 * Mouse-clicking near the target point (or, more
1582 * accurately, in the appropriate octant) is an alternative
1583 * way to input moves.
1586 if (FROMCOORD(x) != state->px || FROMCOORD(y) != state->py) {
1590 dx = FROMCOORD(x) - state->px;
1591 dy = FROMCOORD(y) - state->py;
1592 /* I pass dx,dy rather than dy,dx so that the octants
1593 * end up the right way round. */
1594 angle = atan2(dx, -dy);
1596 angle = (angle + (PI/8)) / (PI/4);
1597 assert(angle > -16.0F);
1598 dir = (int)(angle + 16.0F) & 7;
1600 } else if (button == CURSOR_UP || button == (MOD_NUM_KEYPAD | '8'))
1602 else if (button == CURSOR_DOWN || button == (MOD_NUM_KEYPAD | '2'))
1604 else if (button == CURSOR_LEFT || button == (MOD_NUM_KEYPAD | '4'))
1606 else if (button == CURSOR_RIGHT || button == (MOD_NUM_KEYPAD | '6'))
1608 else if (button == (MOD_NUM_KEYPAD | '7'))
1610 else if (button == (MOD_NUM_KEYPAD | '1'))
1612 else if (button == (MOD_NUM_KEYPAD | '9'))
1614 else if (button == (MOD_NUM_KEYPAD | '3'))
1616 else if (IS_CURSOR_SELECT(button) &&
1617 state->soln && state->solnpos < state->soln->len)
1618 dir = state->soln->list[state->solnpos];
1624 * Reject the move if we can't make it at all due to a wall
1627 if (AT(w, h, state->grid, state->px+DX(dir), state->py+DY(dir)) == WALL)
1631 * Reject the move if we're dead!
1637 * Otherwise, we can make the move. All we need to specify is
1640 ui->just_made_move = TRUE;
1641 sprintf(buf, "%d", dir);
1645 static void install_new_solution(game_state *ret, const char *move)
1649 assert (*move == 'S');
1653 sol->len = strlen(move);
1654 sol->list = snewn(sol->len, unsigned char);
1655 for (i = 0; i < sol->len; ++i) sol->list[i] = move[i] - '0';
1657 if (ret->soln && --ret->soln->refcount == 0) {
1658 sfree(ret->soln->list);
1665 ret->cheated = TRUE;
1669 static void discard_solution(game_state *ret)
1671 --ret->soln->refcount;
1672 assert(ret->soln->refcount > 0); /* ret has a soln-pointing dup */
1677 static game_state *execute_move(const game_state *state, const char *move)
1679 int w = state->p.w, h = state->p.h /*, wh = w*h */;
1685 * This is a solve move, so we don't actually _change_ the
1686 * grid but merely set up a stored solution path.
1688 ret = dup_game(state);
1689 install_new_solution(ret, move);
1694 if (dir < 0 || dir >= DIRECTIONS)
1695 return NULL; /* huh? */
1700 if (AT(w, h, state->grid, state->px+DX(dir), state->py+DY(dir)) == WALL)
1701 return NULL; /* wall in the way! */
1704 * Now make the move.
1706 ret = dup_game(state);
1707 ret->distance_moved = 0;
1711 ret->distance_moved++;
1713 if (AT(w, h, ret->grid, ret->px, ret->py) == GEM) {
1714 LV_AT(w, h, ret->grid, ret->px, ret->py) = BLANK;
1718 if (AT(w, h, ret->grid, ret->px, ret->py) == MINE) {
1723 if (AT(w, h, ret->grid, ret->px, ret->py) == STOP ||
1724 AT(w, h, ret->grid, ret->px+DX(dir),
1725 ret->py+DY(dir)) == WALL)
1730 if (ret->dead || ret->gems == 0)
1731 discard_solution(ret);
1732 else if (ret->soln->list[ret->solnpos] == dir) {
1734 assert(ret->solnpos < ret->soln->len); /* or gems == 0 */
1735 assert(!ret->dead); /* or not a solution */
1737 const char *error = NULL;
1738 char *soln = solve_game(NULL, ret, NULL, &error);
1740 install_new_solution(ret, soln);
1742 } else discard_solution(ret);
1749 /* ----------------------------------------------------------------------
1753 static void game_compute_size(const game_params *params, int tilesize,
1756 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
1757 struct { int tilesize; } ads, *ds = &ads;
1758 ads.tilesize = tilesize;
1760 *x = 2 * BORDER + 1 + params->w * TILESIZE;
1761 *y = 2 * BORDER + 1 + params->h * TILESIZE;
1764 static void game_set_size(drawing *dr, game_drawstate *ds,
1765 const game_params *params, int tilesize)
1767 ds->tilesize = tilesize;
1769 assert(!ds->player_background); /* set_size is never called twice */
1770 assert(!ds->player_bg_saved);
1772 ds->player_background = blitter_new(dr, TILESIZE, TILESIZE);
1775 static float *game_colours(frontend *fe, int *ncolours)
1777 float *ret = snewn(3 * NCOLOURS, float);
1780 game_mkhighlight(fe, ret, COL_BACKGROUND, COL_HIGHLIGHT, COL_LOWLIGHT);
1782 ret[COL_OUTLINE * 3 + 0] = 0.0F;
1783 ret[COL_OUTLINE * 3 + 1] = 0.0F;
1784 ret[COL_OUTLINE * 3 + 2] = 0.0F;
1786 ret[COL_PLAYER * 3 + 0] = 0.0F;
1787 ret[COL_PLAYER * 3 + 1] = 1.0F;
1788 ret[COL_PLAYER * 3 + 2] = 0.0F;
1790 ret[COL_DEAD_PLAYER * 3 + 0] = 1.0F;
1791 ret[COL_DEAD_PLAYER * 3 + 1] = 0.0F;
1792 ret[COL_DEAD_PLAYER * 3 + 2] = 0.0F;
1794 ret[COL_MINE * 3 + 0] = 0.0F;
1795 ret[COL_MINE * 3 + 1] = 0.0F;
1796 ret[COL_MINE * 3 + 2] = 0.0F;
1798 ret[COL_GEM * 3 + 0] = 0.6F;
1799 ret[COL_GEM * 3 + 1] = 1.0F;
1800 ret[COL_GEM * 3 + 2] = 1.0F;
1802 for (i = 0; i < 3; i++) {
1803 ret[COL_WALL * 3 + i] = (3 * ret[COL_BACKGROUND * 3 + i] +
1804 1 * ret[COL_HIGHLIGHT * 3 + i]) / 4;
1807 ret[COL_HINT * 3 + 0] = 1.0F;
1808 ret[COL_HINT * 3 + 1] = 1.0F;
1809 ret[COL_HINT * 3 + 2] = 0.0F;
1811 *ncolours = NCOLOURS;
1815 static game_drawstate *game_new_drawstate(drawing *dr, const game_state *state)
1817 int w = state->p.w, h = state->p.h, wh = w*h;
1818 struct game_drawstate *ds = snew(struct game_drawstate);
1823 /* We can't allocate the blitter rectangle for the player background
1824 * until we know what size to make it. */
1825 ds->player_background = NULL;
1826 ds->player_bg_saved = FALSE;
1827 ds->pbgx = ds->pbgy = -1;
1829 ds->p = state->p; /* structure copy */
1830 ds->started = FALSE;
1831 ds->grid = snewn(wh, unsigned short);
1832 for (i = 0; i < wh; i++)
1833 ds->grid[i] = UNDRAWN;
1838 static void game_free_drawstate(drawing *dr, game_drawstate *ds)
1840 if (ds->player_background)
1841 blitter_free(dr, ds->player_background);
1846 static void draw_player(drawing *dr, game_drawstate *ds, int x, int y,
1847 int dead, int hintdir)
1850 int coords[DIRECTIONS*4];
1853 for (d = 0; d < DIRECTIONS; d++) {
1854 float x1, y1, x2, y2, x3, y3, len;
1858 len = sqrt(x1*x1+y1*y1); x1 /= len; y1 /= len;
1862 len = sqrt(x3*x3+y3*y3); x3 /= len; y3 /= len;
1867 coords[d*4+0] = x + TILESIZE/2 + (int)((TILESIZE*3/7) * x1);
1868 coords[d*4+1] = y + TILESIZE/2 + (int)((TILESIZE*3/7) * y1);
1869 coords[d*4+2] = x + TILESIZE/2 + (int)((TILESIZE*3/7) * x2);
1870 coords[d*4+3] = y + TILESIZE/2 + (int)((TILESIZE*3/7) * y2);
1872 draw_polygon(dr, coords, DIRECTIONS*2, COL_DEAD_PLAYER, COL_OUTLINE);
1874 draw_circle(dr, x + TILESIZE/2, y + TILESIZE/2,
1875 TILESIZE/3, COL_PLAYER, COL_OUTLINE);
1878 if (!dead && hintdir >= 0) {
1879 float scale = (DX(hintdir) && DY(hintdir) ? 0.8F : 1.0F);
1880 int ax = (TILESIZE*2/5) * scale * DX(hintdir);
1881 int ay = (TILESIZE*2/5) * scale * DY(hintdir);
1882 int px = -ay, py = ax;
1883 int ox = x + TILESIZE/2, oy = y + TILESIZE/2;
1889 *c++ = ox + px/9 + ax*2/3;
1890 *c++ = oy + py/9 + ay*2/3;
1891 *c++ = ox + px/3 + ax*2/3;
1892 *c++ = oy + py/3 + ay*2/3;
1895 *c++ = ox - px/3 + ax*2/3;
1896 *c++ = oy - py/3 + ay*2/3;
1897 *c++ = ox - px/9 + ax*2/3;
1898 *c++ = oy - py/9 + ay*2/3;
1901 draw_polygon(dr, coords, 7, COL_HINT, COL_OUTLINE);
1904 draw_update(dr, x, y, TILESIZE, TILESIZE);
1907 #define FLASH_DEAD 0x100
1908 #define FLASH_WIN 0x200
1909 #define FLASH_MASK 0x300
1911 static void draw_tile(drawing *dr, game_drawstate *ds, int x, int y, int v)
1913 int tx = COORD(x), ty = COORD(y);
1914 int bg = (v & FLASH_DEAD ? COL_DEAD_PLAYER :
1915 v & FLASH_WIN ? COL_HIGHLIGHT : COL_BACKGROUND);
1919 clip(dr, tx+1, ty+1, TILESIZE-1, TILESIZE-1);
1920 draw_rect(dr, tx+1, ty+1, TILESIZE-1, TILESIZE-1, bg);
1925 coords[0] = tx + TILESIZE;
1926 coords[1] = ty + TILESIZE;
1927 coords[2] = tx + TILESIZE;
1930 coords[5] = ty + TILESIZE;
1931 draw_polygon(dr, coords, 3, COL_LOWLIGHT, COL_LOWLIGHT);
1935 draw_polygon(dr, coords, 3, COL_HIGHLIGHT, COL_HIGHLIGHT);
1937 draw_rect(dr, tx + 1 + HIGHLIGHT_WIDTH, ty + 1 + HIGHLIGHT_WIDTH,
1938 TILESIZE - 2*HIGHLIGHT_WIDTH,
1939 TILESIZE - 2*HIGHLIGHT_WIDTH, COL_WALL);
1940 } else if (v == MINE) {
1941 int cx = tx + TILESIZE / 2;
1942 int cy = ty + TILESIZE / 2;
1943 int r = TILESIZE / 2 - 3;
1945 draw_circle(dr, cx, cy, 5*r/6, COL_MINE, COL_MINE);
1946 draw_rect(dr, cx - r/6, cy - r, 2*(r/6)+1, 2*r+1, COL_MINE);
1947 draw_rect(dr, cx - r, cy - r/6, 2*r+1, 2*(r/6)+1, COL_MINE);
1948 draw_rect(dr, cx-r/3, cy-r/3, r/3, r/4, COL_HIGHLIGHT);
1949 } else if (v == STOP) {
1950 draw_circle(dr, tx + TILESIZE/2, ty + TILESIZE/2,
1951 TILESIZE*3/7, -1, COL_OUTLINE);
1952 draw_rect(dr, tx + TILESIZE*3/7, ty+1,
1953 TILESIZE - 2*(TILESIZE*3/7) + 1, TILESIZE-1, bg);
1954 draw_rect(dr, tx+1, ty + TILESIZE*3/7,
1955 TILESIZE-1, TILESIZE - 2*(TILESIZE*3/7) + 1, bg);
1956 } else if (v == GEM) {
1959 coords[0] = tx+TILESIZE/2;
1960 coords[1] = ty+TILESIZE/2-TILESIZE*5/14;
1961 coords[2] = tx+TILESIZE/2-TILESIZE*5/14;
1962 coords[3] = ty+TILESIZE/2;
1963 coords[4] = tx+TILESIZE/2;
1964 coords[5] = ty+TILESIZE/2+TILESIZE*5/14;
1965 coords[6] = tx+TILESIZE/2+TILESIZE*5/14;
1966 coords[7] = ty+TILESIZE/2;
1968 draw_polygon(dr, coords, 4, COL_GEM, COL_OUTLINE);
1972 draw_update(dr, tx, ty, TILESIZE, TILESIZE);
1975 #define BASE_ANIM_LENGTH 0.1F
1976 #define FLASH_LENGTH 0.3F
1978 static void game_redraw(drawing *dr, game_drawstate *ds,
1979 const game_state *oldstate, const game_state *state,
1980 int dir, const game_ui *ui,
1981 float animtime, float flashtime)
1983 int w = state->p.w, h = state->p.h /*, wh = w*h */;
1992 !((int)(flashtime * 3 / FLASH_LENGTH) % 2))
1993 flashtype = ui->flashtype;
1998 * Erase the player sprite.
2000 if (ds->player_bg_saved) {
2001 assert(ds->player_background);
2002 blitter_load(dr, ds->player_background, ds->pbgx, ds->pbgy);
2003 draw_update(dr, ds->pbgx, ds->pbgy, TILESIZE, TILESIZE);
2004 ds->player_bg_saved = FALSE;
2008 * Initialise a fresh drawstate.
2014 * Blank out the window initially.
2016 game_compute_size(&ds->p, TILESIZE, &wid, &ht);
2017 draw_rect(dr, 0, 0, wid, ht, COL_BACKGROUND);
2018 draw_update(dr, 0, 0, wid, ht);
2021 * Draw the grid lines.
2023 for (y = 0; y <= h; y++)
2024 draw_line(dr, COORD(0), COORD(y), COORD(w), COORD(y),
2026 for (x = 0; x <= w; x++)
2027 draw_line(dr, COORD(x), COORD(0), COORD(x), COORD(h),
2034 * If we're in the process of animating a move, let's start by
2035 * working out how far the player has moved from their _older_
2039 ap = animtime / ui->anim_length;
2040 player_dist = ap * (dir > 0 ? state : oldstate)->distance_moved;
2047 * Draw the grid contents.
2049 * We count the gems as we go round this loop, for the purposes
2050 * of the status bar. Of course we have a gems counter in the
2051 * game_state already, but if we do the counting in this loop
2052 * then it tracks gems being picked up in a sliding move, and
2053 * updates one by one.
2056 for (y = 0; y < h; y++)
2057 for (x = 0; x < w; x++) {
2058 unsigned short v = (unsigned char)state->grid[y*w+x];
2061 * Special case: if the player is in the process of
2062 * moving over a gem, we draw the gem iff they haven't
2065 if (oldstate && oldstate->grid[y*w+x] != state->grid[y*w+x]) {
2067 * Compute the distance from this square to the
2068 * original player position.
2070 int dist = max(abs(x - oldstate->px), abs(y - oldstate->py));
2073 * If the player has reached here, use the new grid
2074 * element. Otherwise use the old one.
2076 if (player_dist < dist)
2077 v = oldstate->grid[y*w+x];
2079 v = state->grid[y*w+x];
2083 * Special case: erase the mine the dead player is
2084 * sitting on. Only at the end of the move.
2086 if (v == MINE && !oldstate && state->dead &&
2087 x == state->px && y == state->py)
2095 if (ds->grid[y*w+x] != v) {
2096 draw_tile(dr, ds, x, y, v);
2097 ds->grid[y*w+x] = v;
2102 * Gem counter in the status bar. We replace it with
2103 * `COMPLETED!' when it reaches zero ... or rather, when the
2104 * _current state_'s gem counter is zero. (Thus, `Gems: 0' is
2105 * shown between the collection of the last gem and the
2106 * completion of the move animation that did it.)
2108 if (state->dead && (!oldstate || oldstate->dead)) {
2109 sprintf(status, "DEAD!");
2110 } else if (state->gems || (oldstate && oldstate->gems)) {
2112 sprintf(status, "Auto-solver used. ");
2115 sprintf(status + strlen(status), "Gems: %d", gems);
2116 } else if (state->cheated) {
2117 sprintf(status, "Auto-solved.");
2119 sprintf(status, "COMPLETED!");
2121 /* We subtract one from the visible death counter if we're still
2122 * animating the move at the end of which the death took place. */
2123 deaths = ui->deaths;
2124 if (oldstate && ui->just_died) {
2129 sprintf(status + strlen(status), " Deaths: %d", deaths);
2130 status_bar(dr, status);
2133 * Draw the player sprite.
2135 assert(!ds->player_bg_saved);
2136 assert(ds->player_background);
2139 nx = COORD(state->px);
2140 ny = COORD(state->py);
2142 ox = COORD(oldstate->px);
2143 oy = COORD(oldstate->py);
2148 ds->pbgx = ox + ap * (nx - ox);
2149 ds->pbgy = oy + ap * (ny - oy);
2151 blitter_save(dr, ds->player_background, ds->pbgx, ds->pbgy);
2152 draw_player(dr, ds, ds->pbgx, ds->pbgy,
2153 (state->dead && !oldstate),
2154 (!oldstate && state->soln ?
2155 state->soln->list[state->solnpos] : -1));
2156 ds->player_bg_saved = TRUE;
2159 static float game_anim_length(const game_state *oldstate,
2160 const game_state *newstate, int dir, game_ui *ui)
2164 dist = newstate->distance_moved;
2166 dist = oldstate->distance_moved;
2167 ui->anim_length = sqrt(dist) * BASE_ANIM_LENGTH;
2168 return ui->anim_length;
2171 static float game_flash_length(const game_state *oldstate,
2172 const game_state *newstate, int dir, game_ui *ui)
2174 if (!oldstate->dead && newstate->dead) {
2175 ui->flashtype = FLASH_DEAD;
2176 return FLASH_LENGTH;
2177 } else if (oldstate->gems && !newstate->gems) {
2178 ui->flashtype = FLASH_WIN;
2179 return FLASH_LENGTH;
2184 static int game_status(const game_state *state)
2187 * We never report the game as lost, on the grounds that if the
2188 * player has died they're quite likely to want to undo and carry
2191 return state->gems == 0 ? +1 : 0;
2194 static int game_timing_state(const game_state *state, game_ui *ui)
2199 static void game_print_size(const game_params *params, float *x, float *y)
2203 static void game_print(drawing *dr, const game_state *state, int tilesize)
2208 #define thegame inertia
2211 const struct game thegame = {
2212 "Inertia", "games.inertia", "inertia",
2214 game_fetch_preset, NULL,
2219 TRUE, game_configure, custom_params,
2227 TRUE, game_can_format_as_text_now, game_text_format,
2235 PREFERRED_TILESIZE, game_compute_size, game_set_size,
2238 game_free_drawstate,
2243 FALSE, FALSE, game_print_size, game_print,
2244 TRUE, /* wants_statusbar */
2245 FALSE, game_timing_state,