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);
96 static void free_params(game_params *params)
101 static game_params *dup_params(game_params *params)
103 game_params *ret = snew(game_params);
104 *ret = *params; /* structure copy */
108 static const struct game_params inertia_presets[] = {
114 static int game_fetch_preset(int i, char **name, game_params **params)
120 if (i < 0 || i >= lenof(inertia_presets))
123 p = inertia_presets[i];
124 ret = dup_params(&p);
125 sprintf(namebuf, "%dx%d", ret->w, ret->h);
126 retname = dupstr(namebuf);
133 static void decode_params(game_params *params, char const *string)
135 params->w = params->h = atoi(string);
136 while (*string && isdigit((unsigned char)*string)) string++;
137 if (*string == 'x') {
139 params->h = atoi(string);
143 static char *encode_params(game_params *params, int full)
147 sprintf(data, "%dx%d", params->w, params->h);
152 static config_item *game_configure(game_params *params)
157 ret = snewn(3, config_item);
159 ret[0].name = "Width";
160 ret[0].type = C_STRING;
161 sprintf(buf, "%d", params->w);
162 ret[0].sval = dupstr(buf);
165 ret[1].name = "Height";
166 ret[1].type = C_STRING;
167 sprintf(buf, "%d", params->h);
168 ret[1].sval = dupstr(buf);
179 static game_params *custom_params(config_item *cfg)
181 game_params *ret = snew(game_params);
183 ret->w = atoi(cfg[0].sval);
184 ret->h = atoi(cfg[1].sval);
189 static char *validate_params(game_params *params, int full)
192 * Avoid completely degenerate cases which only have one
193 * row/column. We probably could generate completable puzzles
194 * of that shape, but they'd be forced to be extremely boring
195 * and at large sizes would take a while to happen upon at
198 if (params->w < 2 || params->h < 2)
199 return "Width and height must both be at least two";
202 * The grid construction algorithm creates 1/5 as many gems as
203 * grid squares, and must create at least one gem to have an
204 * actual puzzle. However, an area-five grid is ruled out by
205 * the above constraint, so the practical minimum is six.
207 if (params->w * params->h < 6)
208 return "Grid area must be at least six squares";
213 /* ----------------------------------------------------------------------
214 * Solver used by grid generator.
217 struct solver_scratch {
218 unsigned char *reachable_from, *reachable_to;
222 static struct solver_scratch *new_scratch(int w, int h)
224 struct solver_scratch *sc = snew(struct solver_scratch);
226 sc->reachable_from = snewn(w * h * DIRECTIONS, unsigned char);
227 sc->reachable_to = snewn(w * h * DIRECTIONS, unsigned char);
228 sc->positions = snewn(w * h * DIRECTIONS, int);
233 static void free_scratch(struct solver_scratch *sc)
235 sfree(sc->reachable_from);
236 sfree(sc->reachable_to);
237 sfree(sc->positions);
241 static int can_go(int w, int h, char *grid,
242 int x1, int y1, int dir1, int x2, int y2, int dir2)
245 * Returns TRUE if we can transition directly from (x1,y1)
246 * going in direction dir1, to (x2,y2) going in direction dir2.
250 * If we're actually in the middle of an unoccupyable square,
251 * we cannot make any move.
253 if (AT(w, h, grid, x1, y1) == WALL ||
254 AT(w, h, grid, x1, y1) == MINE)
258 * If a move is capable of stopping at x1,y1,dir1, and x2,y2 is
259 * the same coordinate as x1,y1, then we can make the
260 * transition (by stopping and changing direction).
262 * For this to be the case, we have to either have a wall
263 * beyond x1,y1,dir1, or have a stop on x1,y1.
265 if (x2 == x1 && y2 == y1 &&
266 (AT(w, h, grid, x1, y1) == STOP ||
267 AT(w, h, grid, x1, y1) == START ||
268 AT(w, h, grid, x1+DX(dir1), y1+DY(dir1)) == WALL))
272 * If a move is capable of continuing here, then x1,y1,dir1 can
273 * move one space further on.
275 if (x2 == x1+DX(dir1) && y2 == y1+DY(dir1) && dir1 == dir2 &&
276 (AT(w, h, grid, x2, y2) == BLANK ||
277 AT(w, h, grid, x2, y2) == GEM ||
278 AT(w, h, grid, x2, y2) == STOP ||
279 AT(w, h, grid, x2, y2) == START))
288 static int find_gem_candidates(int w, int h, char *grid,
289 struct solver_scratch *sc)
293 int sx, sy, gx, gy, gd, pass, possgems;
296 * This function finds all the candidate gem squares, which are
297 * precisely those squares which can be picked up on a loop
298 * from the starting point back to the starting point. Doing
299 * this may involve passing through such a square in the middle
300 * of a move; so simple breadth-first search over the _squares_
301 * of the grid isn't quite adequate, because it might be that
302 * we can only reach a gem from the start by moving over it in
303 * one direction, but can only return to the start if we were
304 * moving over it in another direction.
306 * Instead, we BFS over a space which mentions each grid square
307 * eight times - once for each direction. We also BFS twice:
308 * once to find out what square+direction pairs we can reach
309 * _from_ the start point, and once to find out what pairs we
310 * can reach the start point from. Then a square is reachable
311 * if any of the eight directions for that square has both
315 memset(sc->reachable_from, 0, wh * DIRECTIONS);
316 memset(sc->reachable_to, 0, wh * DIRECTIONS);
319 * Find the starting square.
321 sx = -1; /* placate optimiser */
322 for (sy = 0; sy < h; sy++) {
323 for (sx = 0; sx < w; sx++)
324 if (AT(w, h, grid, sx, sy) == START)
331 for (pass = 0; pass < 2; pass++) {
332 unsigned char *reachable = (pass == 0 ? sc->reachable_from :
334 int sign = (pass == 0 ? +1 : -1);
337 #ifdef SOLVER_DIAGNOSTICS
338 printf("starting pass %d\n", pass);
342 * `head' and `tail' are indices within sc->positions which
343 * track the list of board positions left to process.
346 for (dir = 0; dir < DIRECTIONS; dir++) {
347 int index = (sy*w+sx)*DIRECTIONS+dir;
348 sc->positions[tail++] = index;
349 reachable[index] = TRUE;
350 #ifdef SOLVER_DIAGNOSTICS
351 printf("starting point %d,%d,%d\n", sx, sy, dir);
356 * Now repeatedly pick an element off the list and process
359 while (head < tail) {
360 int index = sc->positions[head++];
361 int dir = index % DIRECTIONS;
362 int x = (index / DIRECTIONS) % w;
363 int y = index / (w * DIRECTIONS);
364 int n, x2, y2, d2, i2;
366 #ifdef SOLVER_DIAGNOSTICS
367 printf("processing point %d,%d,%d\n", x, y, dir);
370 * The places we attempt to switch to here are:
371 * - each possible direction change (all the other
372 * directions in this square)
373 * - one step further in the direction we're going (or
374 * one step back, if we're in the reachable_to pass).
376 for (n = -1; n < DIRECTIONS; n++) {
378 x2 = x + sign * DX(dir);
379 y2 = y + sign * DY(dir);
386 i2 = (y2*w+x2)*DIRECTIONS+d2;
387 if (x2 >= 0 && x2 < w &&
391 #ifdef SOLVER_DIAGNOSTICS
392 printf(" trying point %d,%d,%d", x2, y2, d2);
395 ok = can_go(w, h, grid, x, y, dir, x2, y2, d2);
397 ok = can_go(w, h, grid, x2, y2, d2, x, y, dir);
398 #ifdef SOLVER_DIAGNOSTICS
399 printf(" - %sok\n", ok ? "" : "not ");
402 sc->positions[tail++] = i2;
403 reachable[i2] = TRUE;
411 * And that should be it. Now all we have to do is find the
412 * squares for which there exists _some_ direction such that
413 * the square plus that direction form a tuple which is both
414 * reachable from the start and reachable to the start.
417 for (gy = 0; gy < h; gy++)
418 for (gx = 0; gx < w; gx++)
419 if (AT(w, h, grid, gx, gy) == BLANK) {
420 for (gd = 0; gd < DIRECTIONS; gd++) {
421 int index = (gy*w+gx)*DIRECTIONS+gd;
422 if (sc->reachable_from[index] && sc->reachable_to[index]) {
423 #ifdef SOLVER_DIAGNOSTICS
424 printf("space at %d,%d is reachable via"
425 " direction %d\n", gx, gy, gd);
427 LV_AT(w, h, grid, gx, gy) = POSSGEM;
437 /* ----------------------------------------------------------------------
438 * Grid generation code.
441 static char *gengrid(int w, int h, random_state *rs)
444 char *grid = snewn(wh+1, char);
445 struct solver_scratch *sc = new_scratch(w, h);
446 int maxdist_threshold, tries;
448 maxdist_threshold = 2;
454 int *dist, *list, head, tail, maxdist;
457 * We're going to fill the grid with the five basic piece
458 * types in about 1/5 proportion. For the moment, though,
459 * we leave out the gems, because we'll put those in
460 * _after_ we run the solver to tell us where the viable
464 for (j = 0; j < wh/5; j++)
466 for (j = 0; j < wh/5; j++)
468 for (j = 0; j < wh/5; j++)
474 shuffle(grid, wh, sizeof(*grid), rs);
477 * Find the viable gem locations, and immediately give up
478 * and try again if there aren't enough of them.
480 possgems = find_gem_candidates(w, h, grid, sc);
485 * We _could_ now select wh/5 of the POSSGEMs and set them
486 * to GEM, and have a viable level. However, there's a
487 * chance that a large chunk of the level will turn out to
488 * be unreachable, so first we test for that.
490 * We do this by finding the largest distance from any
491 * square to the nearest POSSGEM, by breadth-first search.
492 * If this is above a critical threshold, we abort and try
495 * (This search is purely geometric, without regard to
496 * walls and long ways round.)
498 dist = sc->positions;
499 list = sc->positions + wh;
500 for (i = 0; i < wh; i++)
503 for (i = 0; i < wh; i++)
504 if (grid[i] == POSSGEM) {
509 while (head < tail) {
513 if (maxdist < dist[pos])
519 for (d = 0; d < DIRECTIONS; d++) {
525 if (x2 >= 0 && x2 < w && y2 >= 0 && y2 < h) {
528 dist[p2] = dist[pos] + 1;
534 assert(head == wh && tail == wh);
537 * Now abandon this grid and go round again if maxdist is
538 * above the required threshold.
540 * We can safely start the threshold as low as 2. As we
541 * accumulate failed generation attempts, we gradually
542 * raise it as we get more desperate.
544 if (maxdist > maxdist_threshold) {
554 * Now our reachable squares are plausibly evenly
555 * distributed over the grid. I'm not actually going to
556 * _enforce_ that I place the gems in such a way as not to
557 * increase that maxdist value; I'm now just going to trust
558 * to the RNG to pick a sensible subset of the POSSGEMs.
561 for (i = 0; i < wh; i++)
562 if (grid[i] == POSSGEM)
564 shuffle(list, j, sizeof(*list), rs);
565 for (i = 0; i < j; i++)
566 grid[list[i]] = (i < wh/5 ? GEM : BLANK);
577 static char *new_game_desc(game_params *params, random_state *rs,
578 char **aux, int interactive)
580 return gengrid(params->w, params->h, rs);
583 static char *validate_desc(game_params *params, char *desc)
585 int w = params->w, h = params->h, wh = w*h;
586 int starts = 0, gems = 0, i;
588 for (i = 0; i < wh; i++) {
590 return "Not enough data to fill grid";
591 if (desc[i] != WALL && desc[i] != START && desc[i] != STOP &&
592 desc[i] != GEM && desc[i] != MINE && desc[i] != BLANK)
593 return "Unrecognised character in game description";
594 if (desc[i] == START)
600 return "Too much data to fill grid";
602 return "No starting square specified";
604 return "More than one starting square specified";
606 return "No gems specified";
611 static game_state *new_game(midend *me, game_params *params, char *desc)
613 int w = params->w, h = params->h, wh = w*h;
615 game_state *state = snew(game_state);
617 state->p = *params; /* structure copy */
619 state->grid = snewn(wh, char);
620 assert(strlen(desc) == wh);
621 memcpy(state->grid, desc, wh);
623 state->px = state->py = -1;
625 for (i = 0; i < wh; i++) {
626 if (state->grid[i] == START) {
627 state->grid[i] = STOP;
630 } else if (state->grid[i] == GEM) {
635 assert(state->gems > 0);
636 assert(state->px >= 0 && state->py >= 0);
638 state->distance_moved = 0;
641 state->cheated = FALSE;
648 static game_state *dup_game(game_state *state)
650 int w = state->p.w, h = state->p.h, wh = w*h;
651 game_state *ret = snew(game_state);
656 ret->gems = state->gems;
657 ret->grid = snewn(wh, char);
658 ret->distance_moved = state->distance_moved;
660 memcpy(ret->grid, state->grid, wh);
661 ret->cheated = state->cheated;
662 ret->soln = state->soln;
664 ret->soln->refcount++;
665 ret->solnpos = state->solnpos;
670 static void free_game(game_state *state)
672 if (state->soln && --state->soln->refcount == 0) {
673 sfree(state->soln->list);
681 * Internal function used by solver.
683 static int move_goes_to(int w, int h, char *grid, int x, int y, int d)
688 * See where we'd get to if we made this move.
690 dr = -1; /* placate optimiser */
692 if (AT(w, h, grid, x+DX(d), y+DY(d)) == WALL) {
693 dr = DIRECTIONS; /* hit a wall, so end up stationary */
698 if (AT(w, h, grid, x, y) == STOP) {
699 dr = DIRECTIONS; /* hit a stop, so end up stationary */
702 if (AT(w, h, grid, x, y) == GEM) {
703 dr = d; /* hit a gem, so we're still moving */
706 if (AT(w, h, grid, x, y) == MINE)
707 return -1; /* hit a mine, so move is invalid */
710 return (y*w+x)*DP1+dr;
713 static int compare_integers(const void *av, const void *bv)
715 const int *a = (const int *)av;
716 const int *b = (const int *)bv;
725 static char *solve_game(game_state *state, game_state *currstate,
726 char *aux, char **error)
728 int w = state->p.w, h = state->p.h, wh = w*h;
729 int *nodes, *nodeindex, *edges, *backedges, *edgei, *backedgei, *circuit;
731 int *dist, *dist2, *list;
733 int circuitlen, circuitsize;
734 int head, tail, pass, i, j, n, x, y, d, dd;
735 char *err, *soln, *p;
738 * Solving Inertia is a question of first building up the graph
739 * of where you can get to from where, and secondly finding a
740 * tour of the graph which takes in every gem.
742 * This is of course a close cousin of the travelling salesman
743 * problem, which is NP-complete; so I rather doubt that any
744 * _optimal_ tour can be found in plausible time. Hence I'll
745 * restrict myself to merely finding a not-too-bad one.
747 * First construct the graph, by bfsing out move by move from
748 * the current player position. Graph vertices will be
749 * - every endpoint of a move (place the ball can be
751 * - every gem (place the ball can go through in motion).
752 * Vertices of this type have an associated direction, since
753 * if a gem can be collected by sliding through it in two
754 * different directions it doesn't follow that you can
755 * change direction at it.
757 * I'm going to refer to a non-directional vertex as
758 * (y*w+x)*DP1+DIRECTIONS, and a directional one as
763 * nodeindex[] maps node codes as shown above to numeric
764 * indices in the nodes[] array.
766 nodeindex = snewn(DP1*wh, int);
767 for (i = 0; i < DP1*wh; i++)
771 * Do the bfs to find all the interesting graph nodes.
773 nodes = snewn(DP1*wh, int);
776 nodes[tail] = (currstate->py * w + currstate->px) * DP1 + DIRECTIONS;
777 nodeindex[nodes[0]] = tail;
780 while (head < tail) {
781 int nc = nodes[head++], nnc;
786 * Plot all possible moves from this node. If the node is
787 * directed, there's only one.
789 for (dd = 0; dd < DIRECTIONS; dd++) {
794 if (d < DIRECTIONS && d != dd)
797 nnc = move_goes_to(w, h, currstate->grid, x, y, dd);
798 if (nnc >= 0 && nnc != nc) {
799 if (nodeindex[nnc] < 0) {
801 nodeindex[nnc] = tail;
810 * Now we know how many nodes we have, allocate the edge array
811 * and go through setting up the edges.
813 edges = snewn(DIRECTIONS*n, int);
814 edgei = snewn(n+1, int);
817 for (i = 0; i < n; i++) {
827 for (dd = 0; dd < DIRECTIONS; dd++) {
830 if (d >= DIRECTIONS || d == dd) {
831 nnc = move_goes_to(w, h, currstate->grid, x, y, dd);
833 if (nnc >= 0 && nnc != nc)
834 edges[nedges++] = nodeindex[nnc];
841 * Now set up the backedges array.
843 backedges = snewn(nedges, int);
844 backedgei = snewn(n+1, int);
845 for (i = j = 0; i < nedges; i++) {
846 while (j+1 < n && i >= edgei[j+1])
848 backedges[i] = edges[i] * n + j;
850 qsort(backedges, nedges, sizeof(int), compare_integers);
852 for (i = j = 0; i < nedges; i++) {
853 int k = backedges[i] / n;
858 backedgei[n] = nedges;
861 * Set up the initial tour. At all times, our tour is a circuit
862 * of graph vertices (which may, and probably will often,
863 * repeat vertices). To begin with, it's got exactly one vertex
864 * in it, which is the player's current starting point.
867 circuit = snewn(circuitsize, int);
869 circuit[circuitlen++] = 0; /* node index 0 is the starting posn */
872 * Track which gems are as yet unvisited.
874 unvisited = snewn(wh, int);
875 for (i = 0; i < wh; i++)
876 unvisited[i] = FALSE;
877 for (i = 0; i < wh; i++)
878 if (currstate->grid[i] == GEM)
882 * Allocate space for doing bfses inside the main loop.
884 dist = snewn(n, int);
885 dist2 = snewn(n, int);
886 list = snewn(n, int);
892 * Now enter the main loop, in each iteration of which we
893 * extend the tour to take in an as yet uncollected gem.
896 int target, n1, n2, bestdist, extralen, targetpos;
898 #ifdef TSP_DIAGNOSTICS
899 printf("circuit is");
900 for (i = 0; i < circuitlen; i++) {
901 int nc = nodes[circuit[i]];
902 printf(" (%d,%d,%d)", nc/DP1%w, nc/(DP1*w), nc%DP1);
905 printf("moves are ");
906 x = nodes[circuit[0]] / DP1 % w;
907 y = nodes[circuit[0]] / DP1 / w;
908 for (i = 1; i < circuitlen; i++) {
910 if (nodes[circuit[i]] % DP1 != DIRECTIONS)
912 x2 = nodes[circuit[i]] / DP1 % w;
913 y2 = nodes[circuit[i]] / DP1 / w;
914 dx = (x2 > x ? +1 : x2 < x ? -1 : 0);
915 dy = (y2 > y ? +1 : y2 < y ? -1 : 0);
916 for (d = 0; d < DIRECTIONS; d++)
917 if (DX(d) == dx && DY(d) == dy)
918 printf("%c", "89632147"[d]);
926 * First, start a pair of bfses at _every_ vertex currently
927 * in the tour, and extend them outwards to find the
928 * nearest as yet unreached gem vertex.
930 * This is largely a heuristic: we could pick _any_ doubly
931 * reachable node here and still get a valid tour as
932 * output. I hope that picking a nearby one will result in
933 * generally good tours.
935 for (pass = 0; pass < 2; pass++) {
936 int *ep = (pass == 0 ? edges : backedges);
937 int *ei = (pass == 0 ? edgei : backedgei);
938 int *dp = (pass == 0 ? dist : dist2);
940 for (i = 0; i < n; i++)
942 for (i = 0; i < circuitlen; i++) {
949 while (head < tail) {
950 int ni = list[head++];
951 for (i = ei[ni]; i < ei[ni+1]; i++) {
953 if (ti >= 0 && dp[ti] < 0) {
960 /* Now find the nearest unvisited gem. */
963 for (i = 0; i < n; i++) {
964 if (unvisited[nodes[i] / DP1] &&
965 dist[i] >= 0 && dist2[i] >= 0) {
966 int thisdist = dist[i] + dist2[i];
967 if (bestdist < 0 || bestdist > thisdist) {
976 * If we get to here, we haven't found a gem we can get
977 * at all, which means we terminate this loop.
983 * Now we have a graph vertex at list[tail-1] which is an
984 * unvisited gem. We want to add that vertex to our tour.
985 * So we run two more breadth-first searches: one starting
986 * from that vertex and following forward edges, and
987 * another starting from the same vertex and following
988 * backward edges. This allows us to determine, for each
989 * node on the current tour, how quickly we can get both to
990 * and from the target vertex from that node.
992 #ifdef TSP_DIAGNOSTICS
993 printf("target node is %d (%d,%d,%d)\n", target, nodes[target]/DP1%w,
994 nodes[target]/DP1/w, nodes[target]%DP1);
997 for (pass = 0; pass < 2; pass++) {
998 int *ep = (pass == 0 ? edges : backedges);
999 int *ei = (pass == 0 ? edgei : backedgei);
1000 int *dp = (pass == 0 ? dist : dist2);
1002 for (i = 0; i < n; i++)
1007 list[tail++] = target;
1009 while (head < tail) {
1010 int ni = list[head++];
1011 for (i = ei[ni]; i < ei[ni+1]; i++) {
1013 if (ti >= 0 && dp[ti] < 0) {
1014 dp[ti] = dp[ni] + 1;
1015 /*printf("pass %d: set dist of vertex %d to %d (via %d)\n", pass, ti, dp[ti], ni);*/
1023 * Now for every node n, dist[n] gives the length of the
1024 * shortest path from the target vertex to n, and dist2[n]
1025 * gives the length of the shortest path from n to the
1028 * Our next step is to search linearly along the tour to
1029 * find the optimum place to insert a trip to the target
1030 * vertex and back. Our two options are either
1031 * (a) to find two adjacent vertices A,B in the tour and
1032 * replace the edge A->B with the path A->target->B
1033 * (b) to find a single vertex X in the tour and replace
1034 * it with the complete round trip X->target->X.
1035 * We do whichever takes the fewest moves.
1039 for (i = 0; i < circuitlen; i++) {
1043 * Try a round trip from vertex i.
1045 if (dist[circuit[i]] >= 0 &&
1046 dist2[circuit[i]] >= 0) {
1047 thisdist = dist[circuit[i]] + dist2[circuit[i]];
1048 if (bestdist < 0 || thisdist < bestdist) {
1049 bestdist = thisdist;
1055 * Try a trip from vertex i via target to vertex i+1.
1057 if (i+1 < circuitlen &&
1058 dist2[circuit[i]] >= 0 &&
1059 dist[circuit[i+1]] >= 0) {
1060 thisdist = dist2[circuit[i]] + dist[circuit[i+1]];
1061 if (bestdist < 0 || thisdist < bestdist) {
1062 bestdist = thisdist;
1070 * We couldn't find a round trip taking in this gem _at
1073 err = "Unable to find a solution from this starting point";
1076 #ifdef TSP_DIAGNOSTICS
1077 printf("insertion point: n1=%d, n2=%d, dist=%d\n", n1, n2, bestdist);
1080 #ifdef TSP_DIAGNOSTICS
1081 printf("circuit before lengthening is");
1082 for (i = 0; i < circuitlen; i++) {
1083 printf(" %d", circuit[i]);
1089 * Now actually lengthen the tour to take in this round
1092 extralen = dist2[circuit[n1]] + dist[circuit[n2]];
1095 circuitlen += extralen;
1096 if (circuitlen >= circuitsize) {
1097 circuitsize = circuitlen + 256;
1098 circuit = sresize(circuit, circuitsize, int);
1100 memmove(circuit + n2 + extralen, circuit + n2,
1101 (circuitlen - n2 - extralen) * sizeof(int));
1104 #ifdef TSP_DIAGNOSTICS
1105 printf("circuit in middle of lengthening is");
1106 for (i = 0; i < circuitlen; i++) {
1107 printf(" %d", circuit[i]);
1113 * Find the shortest-path routes to and from the target,
1114 * and write them into the circuit.
1116 targetpos = n1 + dist2[circuit[n1]];
1117 assert(targetpos - dist2[circuit[n1]] == n1);
1118 assert(targetpos + dist[circuit[n2]] == n2);
1119 for (pass = 0; pass < 2; pass++) {
1120 int dir = (pass == 0 ? -1 : +1);
1121 int *ep = (pass == 0 ? backedges : edges);
1122 int *ei = (pass == 0 ? backedgei : edgei);
1123 int *dp = (pass == 0 ? dist : dist2);
1124 int nn = (pass == 0 ? n2 : n1);
1125 int ni = circuit[nn], ti, dest = nn;
1133 /*printf("pass %d: looking at vertex %d\n", pass, ni);*/
1134 for (i = ei[ni]; i < ei[ni+1]; i++) {
1136 if (ti >= 0 && dp[ti] == dp[ni] - 1)
1139 assert(i < ei[ni+1] && ti >= 0);
1144 #ifdef TSP_DIAGNOSTICS
1145 printf("circuit after lengthening is");
1146 for (i = 0; i < circuitlen; i++) {
1147 printf(" %d", circuit[i]);
1153 * Finally, mark all gems that the new piece of circuit
1154 * passes through as visited.
1156 for (i = n1; i <= n2; i++) {
1157 int pos = nodes[circuit[i]] / DP1;
1158 assert(pos >= 0 && pos < wh);
1159 unvisited[pos] = FALSE;
1163 #ifdef TSP_DIAGNOSTICS
1164 printf("before reduction, moves are ");
1165 x = nodes[circuit[0]] / DP1 % w;
1166 y = nodes[circuit[0]] / DP1 / w;
1167 for (i = 1; i < circuitlen; i++) {
1169 if (nodes[circuit[i]] % DP1 != DIRECTIONS)
1171 x2 = nodes[circuit[i]] / DP1 % w;
1172 y2 = nodes[circuit[i]] / DP1 / w;
1173 dx = (x2 > x ? +1 : x2 < x ? -1 : 0);
1174 dy = (y2 > y ? +1 : y2 < y ? -1 : 0);
1175 for (d = 0; d < DIRECTIONS; d++)
1176 if (DX(d) == dx && DY(d) == dy)
1177 printf("%c", "89632147"[d]);
1185 * That's got a basic solution. Now optimise it by removing
1186 * redundant sections of the circuit: it's entirely possible
1187 * that a piece of circuit we carefully inserted at one stage
1188 * to collect a gem has become pointless because the steps
1189 * required to collect some _later_ gem necessarily passed
1190 * through the same one.
1192 * So first we go through and work out how many times each gem
1193 * is collected. Then we look for maximal sections of circuit
1194 * which are redundant in the sense that their removal would
1195 * not reduce any gem's collection count to zero, and replace
1196 * each one with a bfs-derived fastest path between their
1200 int oldlen = circuitlen;
1203 for (dir = +1; dir >= -1; dir -= 2) {
1205 for (i = 0; i < wh; i++)
1207 for (i = 0; i < circuitlen; i++) {
1208 int xy = nodes[circuit[i]] / DP1;
1209 if (currstate->grid[xy] == GEM)
1214 * If there's any gem we didn't end up visiting at all,
1217 for (i = 0; i < wh; i++) {
1218 if (currstate->grid[i] == GEM && unvisited[i] == 0) {
1219 err = "Unable to find a solution from this starting point";
1226 for (i = j = (dir > 0 ? 0 : circuitlen-1);
1227 i < circuitlen && i >= 0;
1229 int xy = nodes[circuit[i]] / DP1;
1230 if (currstate->grid[xy] == GEM && unvisited[xy] > 1) {
1232 } else if (currstate->grid[xy] == GEM || i == circuitlen-1) {
1234 * circuit[i] collects a gem for the only time,
1235 * or is the last node in the circuit.
1236 * Therefore it cannot be removed; so we now
1237 * want to replace the path from circuit[j] to
1238 * circuit[i] with a bfs-shortest path.
1240 int p, q, k, dest, ni, ti, thisdist;
1243 * Set up the upper and lower bounds of the
1249 #ifdef TSP_DIAGNOSTICS
1250 printf("optimising section from %d - %d\n", p, q);
1253 for (k = 0; k < n; k++)
1257 dist[circuit[p]] = 0;
1258 list[tail++] = circuit[p];
1260 while (head < tail && dist[circuit[q]] < 0) {
1261 int ni = list[head++];
1262 for (k = edgei[ni]; k < edgei[ni+1]; k++) {
1264 if (ti >= 0 && dist[ti] < 0) {
1265 dist[ti] = dist[ni] + 1;
1271 thisdist = dist[circuit[q]];
1272 assert(thisdist >= 0 && thisdist <= q-p);
1274 memmove(circuit+p+thisdist, circuit+q,
1275 (circuitlen - q) * sizeof(int));
1281 i = q; /* resume loop from the right place */
1283 #ifdef TSP_DIAGNOSTICS
1284 printf("new section runs from %d - %d\n", p, q);
1292 /* printf("dest=%d circuitlen=%d ni=%d dist[ni]=%d\n", dest, circuitlen, ni, dist[ni]); */
1298 for (k = backedgei[ni]; k < backedgei[ni+1]; k++) {
1300 if (ti >= 0 && dist[ti] == dist[ni] - 1)
1303 assert(k < backedgei[ni+1] && ti >= 0);
1308 * Now re-increment the visit counts for the
1312 int xy = nodes[circuit[p]] / DP1;
1313 if (currstate->grid[xy] == GEM)
1319 #ifdef TSP_DIAGNOSTICS
1320 printf("during reduction, circuit is");
1321 for (k = 0; k < circuitlen; k++) {
1322 int nc = nodes[circuit[k]];
1323 printf(" (%d,%d,%d)", nc/DP1%w, nc/(DP1*w), nc%DP1);
1326 printf("moves are ");
1327 x = nodes[circuit[0]] / DP1 % w;
1328 y = nodes[circuit[0]] / DP1 / w;
1329 for (k = 1; k < circuitlen; k++) {
1331 if (nodes[circuit[k]] % DP1 != DIRECTIONS)
1333 x2 = nodes[circuit[k]] / DP1 % w;
1334 y2 = nodes[circuit[k]] / DP1 / w;
1335 dx = (x2 > x ? +1 : x2 < x ? -1 : 0);
1336 dy = (y2 > y ? +1 : y2 < y ? -1 : 0);
1337 for (d = 0; d < DIRECTIONS; d++)
1338 if (DX(d) == dx && DY(d) == dy)
1339 printf("%c", "89632147"[d]);
1348 #ifdef TSP_DIAGNOSTICS
1349 printf("after reduction, moves are ");
1350 x = nodes[circuit[0]] / DP1 % w;
1351 y = nodes[circuit[0]] / DP1 / w;
1352 for (i = 1; i < circuitlen; i++) {
1354 if (nodes[circuit[i]] % DP1 != DIRECTIONS)
1356 x2 = nodes[circuit[i]] / DP1 % w;
1357 y2 = nodes[circuit[i]] / DP1 / w;
1358 dx = (x2 > x ? +1 : x2 < x ? -1 : 0);
1359 dy = (y2 > y ? +1 : y2 < y ? -1 : 0);
1360 for (d = 0; d < DIRECTIONS; d++)
1361 if (DX(d) == dx && DY(d) == dy)
1362 printf("%c", "89632147"[d]);
1371 * If we've managed an entire reduction pass in each
1372 * direction and not made the solution any shorter, we're
1375 if (circuitlen == oldlen)
1380 * Encode the solution as a move string.
1383 soln = snewn(circuitlen+2, char);
1386 x = nodes[circuit[0]] / DP1 % w;
1387 y = nodes[circuit[0]] / DP1 / w;
1388 for (i = 1; i < circuitlen; i++) {
1390 if (nodes[circuit[i]] % DP1 != DIRECTIONS)
1392 x2 = nodes[circuit[i]] / DP1 % w;
1393 y2 = nodes[circuit[i]] / DP1 / w;
1394 dx = (x2 > x ? +1 : x2 < x ? -1 : 0);
1395 dy = (y2 > y ? +1 : y2 < y ? -1 : 0);
1396 for (d = 0; d < DIRECTIONS; d++)
1397 if (DX(d) == dx && DY(d) == dy) {
1401 assert(d < DIRECTIONS);
1406 assert(p - soln < circuitlen+2);
1427 static char *game_text_format(game_state *state)
1440 static game_ui *new_ui(game_state *state)
1442 game_ui *ui = snew(game_ui);
1443 ui->anim_length = 0.0F;
1446 ui->just_made_move = FALSE;
1447 ui->just_died = FALSE;
1451 static void free_ui(game_ui *ui)
1456 static char *encode_ui(game_ui *ui)
1460 * The deaths counter needs preserving across a serialisation.
1462 sprintf(buf, "D%d", ui->deaths);
1466 static void decode_ui(game_ui *ui, char *encoding)
1469 sscanf(encoding, "D%d%n", &ui->deaths, &p);
1472 static void game_changed_state(game_ui *ui, game_state *oldstate,
1473 game_state *newstate)
1476 * Increment the deaths counter. We only do this if
1477 * ui->just_made_move is set (redoing a suicide move doesn't
1478 * kill you _again_), and also we only do it if the game wasn't
1479 * already completed (once you're finished, you can play).
1481 if (!oldstate->dead && newstate->dead && ui->just_made_move &&
1484 ui->just_died = TRUE;
1486 ui->just_died = FALSE;
1488 ui->just_made_move = FALSE;
1491 struct game_drawstate {
1495 unsigned short *grid;
1496 blitter *player_background;
1497 int player_bg_saved, pbgx, pbgy;
1500 #define PREFERRED_TILESIZE 32
1501 #define TILESIZE (ds->tilesize)
1502 #define BORDER (TILESIZE)
1503 #define HIGHLIGHT_WIDTH (TILESIZE / 10)
1504 #define COORD(x) ( (x) * TILESIZE + BORDER )
1505 #define FROMCOORD(x) ( ((x) - BORDER + TILESIZE) / TILESIZE - 1 )
1507 static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds,
1508 int x, int y, int button)
1510 int w = state->p.w, h = state->p.h /*, wh = w*h */;
1516 if (button == LEFT_BUTTON) {
1518 * Mouse-clicking near the target point (or, more
1519 * accurately, in the appropriate octant) is an alternative
1520 * way to input moves.
1523 if (FROMCOORD(x) != state->px || FROMCOORD(y) != state->py) {
1527 dx = FROMCOORD(x) - state->px;
1528 dy = FROMCOORD(y) - state->py;
1529 /* I pass dx,dy rather than dy,dx so that the octants
1530 * end up the right way round. */
1531 angle = atan2(dx, -dy);
1533 angle = (angle + (PI/8)) / (PI/4);
1534 assert(angle > -16.0F);
1535 dir = (int)(angle + 16.0F) & 7;
1537 } else if (button == CURSOR_UP || button == (MOD_NUM_KEYPAD | '8'))
1539 else if (button == CURSOR_DOWN || button == (MOD_NUM_KEYPAD | '2'))
1541 else if (button == CURSOR_LEFT || button == (MOD_NUM_KEYPAD | '4'))
1543 else if (button == CURSOR_RIGHT || button == (MOD_NUM_KEYPAD | '6'))
1545 else if (button == (MOD_NUM_KEYPAD | '7'))
1547 else if (button == (MOD_NUM_KEYPAD | '1'))
1549 else if (button == (MOD_NUM_KEYPAD | '9'))
1551 else if (button == (MOD_NUM_KEYPAD | '3'))
1553 else if (button == ' ' && state->soln && state->solnpos < state->soln->len)
1554 dir = state->soln->list[state->solnpos];
1560 * Reject the move if we can't make it at all due to a wall
1563 if (AT(w, h, state->grid, state->px+DX(dir), state->py+DY(dir)) == WALL)
1567 * Reject the move if we're dead!
1573 * Otherwise, we can make the move. All we need to specify is
1576 ui->just_made_move = TRUE;
1577 sprintf(buf, "%d", dir);
1581 static game_state *execute_move(game_state *state, char *move)
1583 int w = state->p.w, h = state->p.h /*, wh = w*h */;
1592 * This is a solve move, so we don't actually _change_ the
1593 * grid but merely set up a stored solution path.
1599 sol->list = snewn(len, unsigned char);
1600 for (i = 0; i < len; i++)
1601 sol->list[i] = move[i] - '0';
1602 ret = dup_game(state);
1603 ret->cheated = TRUE;
1611 if (dir < 0 || dir >= DIRECTIONS)
1612 return NULL; /* huh? */
1617 if (AT(w, h, state->grid, state->px+DX(dir), state->py+DY(dir)) == WALL)
1618 return NULL; /* wall in the way! */
1621 * Now make the move.
1623 ret = dup_game(state);
1624 ret->distance_moved = 0;
1628 ret->distance_moved++;
1630 if (AT(w, h, ret->grid, ret->px, ret->py) == GEM) {
1631 LV_AT(w, h, ret->grid, ret->px, ret->py) = BLANK;
1635 if (AT(w, h, ret->grid, ret->px, ret->py) == MINE) {
1640 if (AT(w, h, ret->grid, ret->px, ret->py) == STOP ||
1641 AT(w, h, ret->grid, ret->px+DX(dir),
1642 ret->py+DY(dir)) == WALL)
1648 * If this move is the correct next one in the stored
1649 * solution path, advance solnpos.
1651 if (ret->soln->list[ret->solnpos] == dir &&
1652 ret->solnpos+1 < ret->soln->len) {
1656 * Otherwise, the user has strayed from the path, so
1657 * the path is no longer valid.
1659 ret->soln->refcount--;
1660 assert(ret->soln->refcount > 0);/* `state' at least still exists */
1669 /* ----------------------------------------------------------------------
1673 static void game_compute_size(game_params *params, int tilesize,
1676 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
1677 struct { int tilesize; } ads, *ds = &ads;
1678 ads.tilesize = tilesize;
1680 *x = 2 * BORDER + 1 + params->w * TILESIZE;
1681 *y = 2 * BORDER + 1 + params->h * TILESIZE;
1684 static void game_set_size(drawing *dr, game_drawstate *ds,
1685 game_params *params, int tilesize)
1687 ds->tilesize = tilesize;
1689 assert(!ds->player_background); /* set_size is never called twice */
1690 assert(!ds->player_bg_saved);
1692 ds->player_background = blitter_new(dr, TILESIZE, TILESIZE);
1695 static float *game_colours(frontend *fe, int *ncolours)
1697 float *ret = snewn(3 * NCOLOURS, float);
1700 game_mkhighlight(fe, ret, COL_BACKGROUND, COL_HIGHLIGHT, COL_LOWLIGHT);
1702 ret[COL_OUTLINE * 3 + 0] = 0.0F;
1703 ret[COL_OUTLINE * 3 + 1] = 0.0F;
1704 ret[COL_OUTLINE * 3 + 2] = 0.0F;
1706 ret[COL_PLAYER * 3 + 0] = 0.0F;
1707 ret[COL_PLAYER * 3 + 1] = 1.0F;
1708 ret[COL_PLAYER * 3 + 2] = 0.0F;
1710 ret[COL_DEAD_PLAYER * 3 + 0] = 1.0F;
1711 ret[COL_DEAD_PLAYER * 3 + 1] = 0.0F;
1712 ret[COL_DEAD_PLAYER * 3 + 2] = 0.0F;
1714 ret[COL_MINE * 3 + 0] = 0.0F;
1715 ret[COL_MINE * 3 + 1] = 0.0F;
1716 ret[COL_MINE * 3 + 2] = 0.0F;
1718 ret[COL_GEM * 3 + 0] = 0.6F;
1719 ret[COL_GEM * 3 + 1] = 1.0F;
1720 ret[COL_GEM * 3 + 2] = 1.0F;
1722 for (i = 0; i < 3; i++) {
1723 ret[COL_WALL * 3 + i] = (3 * ret[COL_BACKGROUND * 3 + i] +
1724 1 * ret[COL_HIGHLIGHT * 3 + i]) / 4;
1727 ret[COL_HINT * 3 + 0] = 1.0F;
1728 ret[COL_HINT * 3 + 1] = 1.0F;
1729 ret[COL_HINT * 3 + 2] = 0.0F;
1731 *ncolours = NCOLOURS;
1735 static game_drawstate *game_new_drawstate(drawing *dr, game_state *state)
1737 int w = state->p.w, h = state->p.h, wh = w*h;
1738 struct game_drawstate *ds = snew(struct game_drawstate);
1743 /* We can't allocate the blitter rectangle for the player background
1744 * until we know what size to make it. */
1745 ds->player_background = NULL;
1746 ds->player_bg_saved = FALSE;
1747 ds->pbgx = ds->pbgy = -1;
1749 ds->p = state->p; /* structure copy */
1750 ds->started = FALSE;
1751 ds->grid = snewn(wh, unsigned short);
1752 for (i = 0; i < wh; i++)
1753 ds->grid[i] = UNDRAWN;
1758 static void game_free_drawstate(drawing *dr, game_drawstate *ds)
1760 if (ds->player_background)
1761 blitter_free(dr, ds->player_background);
1766 static void draw_player(drawing *dr, game_drawstate *ds, int x, int y,
1767 int dead, int hintdir)
1770 int coords[DIRECTIONS*4];
1773 for (d = 0; d < DIRECTIONS; d++) {
1774 float x1, y1, x2, y2, x3, y3, len;
1778 len = sqrt(x1*x1+y1*y1); x1 /= len; y1 /= len;
1782 len = sqrt(x3*x3+y3*y3); x3 /= len; y3 /= len;
1787 coords[d*4+0] = x + TILESIZE/2 + (int)((TILESIZE*3/7) * x1);
1788 coords[d*4+1] = y + TILESIZE/2 + (int)((TILESIZE*3/7) * y1);
1789 coords[d*4+2] = x + TILESIZE/2 + (int)((TILESIZE*3/7) * x2);
1790 coords[d*4+3] = y + TILESIZE/2 + (int)((TILESIZE*3/7) * y2);
1792 draw_polygon(dr, coords, DIRECTIONS*2, COL_DEAD_PLAYER, COL_OUTLINE);
1794 draw_circle(dr, x + TILESIZE/2, y + TILESIZE/2,
1795 TILESIZE/3, COL_PLAYER, COL_OUTLINE);
1798 if (!dead && hintdir >= 0) {
1799 float scale = (DX(hintdir) && DY(hintdir) ? 0.8F : 1.0F);
1800 int ax = (TILESIZE*2/5) * scale * DX(hintdir);
1801 int ay = (TILESIZE*2/5) * scale * DY(hintdir);
1802 int px = -ay, py = ax;
1803 int ox = x + TILESIZE/2, oy = y + TILESIZE/2;
1809 *c++ = ox + px/9 + ax*2/3;
1810 *c++ = oy + py/9 + ay*2/3;
1811 *c++ = ox + px/3 + ax*2/3;
1812 *c++ = oy + py/3 + ay*2/3;
1815 *c++ = ox - px/3 + ax*2/3;
1816 *c++ = oy - py/3 + ay*2/3;
1817 *c++ = ox - px/9 + ax*2/3;
1818 *c++ = oy - py/9 + ay*2/3;
1821 draw_polygon(dr, coords, 7, COL_HINT, COL_OUTLINE);
1824 draw_update(dr, x, y, TILESIZE, TILESIZE);
1827 #define FLASH_DEAD 0x100
1828 #define FLASH_WIN 0x200
1829 #define FLASH_MASK 0x300
1831 static void draw_tile(drawing *dr, game_drawstate *ds, int x, int y, int v)
1833 int tx = COORD(x), ty = COORD(y);
1834 int bg = (v & FLASH_DEAD ? COL_DEAD_PLAYER :
1835 v & FLASH_WIN ? COL_HIGHLIGHT : COL_BACKGROUND);
1839 clip(dr, tx+1, ty+1, TILESIZE-1, TILESIZE-1);
1840 draw_rect(dr, tx+1, ty+1, TILESIZE-1, TILESIZE-1, bg);
1845 coords[0] = tx + TILESIZE;
1846 coords[1] = ty + TILESIZE;
1847 coords[2] = tx + TILESIZE;
1850 coords[5] = ty + TILESIZE;
1851 draw_polygon(dr, coords, 3, COL_LOWLIGHT, COL_LOWLIGHT);
1855 draw_polygon(dr, coords, 3, COL_HIGHLIGHT, COL_HIGHLIGHT);
1857 draw_rect(dr, tx + 1 + HIGHLIGHT_WIDTH, ty + 1 + HIGHLIGHT_WIDTH,
1858 TILESIZE - 2*HIGHLIGHT_WIDTH,
1859 TILESIZE - 2*HIGHLIGHT_WIDTH, COL_WALL);
1860 } else if (v == MINE) {
1861 int cx = tx + TILESIZE / 2;
1862 int cy = ty + TILESIZE / 2;
1863 int r = TILESIZE / 2 - 3;
1865 int xdx = 1, xdy = 0, ydx = 0, ydy = 1;
1868 for (i = 0; i < 4*5*2; i += 5*2) {
1869 coords[i+2*0+0] = cx - r/6*xdx + r*4/5*ydx;
1870 coords[i+2*0+1] = cy - r/6*xdy + r*4/5*ydy;
1871 coords[i+2*1+0] = cx - r/6*xdx + r*ydx;
1872 coords[i+2*1+1] = cy - r/6*xdy + r*ydy;
1873 coords[i+2*2+0] = cx + r/6*xdx + r*ydx;
1874 coords[i+2*2+1] = cy + r/6*xdy + r*ydy;
1875 coords[i+2*3+0] = cx + r/6*xdx + r*4/5*ydx;
1876 coords[i+2*3+1] = cy + r/6*xdy + r*4/5*ydy;
1877 coords[i+2*4+0] = cx + r*3/5*xdx + r*3/5*ydx;
1878 coords[i+2*4+1] = cy + r*3/5*xdy + r*3/5*ydy;
1888 draw_polygon(dr, coords, 5*4, COL_MINE, COL_MINE);
1890 draw_rect(dr, cx-r/3, cy-r/3, r/3, r/4, COL_HIGHLIGHT);
1891 } else if (v == STOP) {
1892 draw_circle(dr, tx + TILESIZE/2, ty + TILESIZE/2,
1893 TILESIZE*3/7, -1, COL_OUTLINE);
1894 draw_rect(dr, tx + TILESIZE*3/7, ty+1,
1895 TILESIZE - 2*(TILESIZE*3/7) + 1, TILESIZE-1, bg);
1896 draw_rect(dr, tx+1, ty + TILESIZE*3/7,
1897 TILESIZE-1, TILESIZE - 2*(TILESIZE*3/7) + 1, bg);
1898 } else if (v == GEM) {
1901 coords[0] = tx+TILESIZE/2;
1902 coords[1] = ty+TILESIZE*1/7;
1903 coords[2] = tx+TILESIZE*1/7;
1904 coords[3] = ty+TILESIZE/2;
1905 coords[4] = tx+TILESIZE/2;
1906 coords[5] = ty+TILESIZE-TILESIZE*1/7;
1907 coords[6] = tx+TILESIZE-TILESIZE*1/7;
1908 coords[7] = ty+TILESIZE/2;
1910 draw_polygon(dr, coords, 4, COL_GEM, COL_OUTLINE);
1914 draw_update(dr, tx, ty, TILESIZE, TILESIZE);
1917 #define BASE_ANIM_LENGTH 0.1F
1918 #define FLASH_LENGTH 0.3F
1920 static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate,
1921 game_state *state, int dir, game_ui *ui,
1922 float animtime, float flashtime)
1924 int w = state->p.w, h = state->p.h /*, wh = w*h */;
1933 !((int)(flashtime * 3 / FLASH_LENGTH) % 2))
1934 flashtype = ui->flashtype;
1939 * Erase the player sprite.
1941 if (ds->player_bg_saved) {
1942 assert(ds->player_background);
1943 blitter_load(dr, ds->player_background, ds->pbgx, ds->pbgy);
1944 draw_update(dr, ds->pbgx, ds->pbgy, TILESIZE, TILESIZE);
1945 ds->player_bg_saved = FALSE;
1949 * Initialise a fresh drawstate.
1955 * Blank out the window initially.
1957 game_compute_size(&ds->p, TILESIZE, &wid, &ht);
1958 draw_rect(dr, 0, 0, wid, ht, COL_BACKGROUND);
1959 draw_update(dr, 0, 0, wid, ht);
1962 * Draw the grid lines.
1964 for (y = 0; y <= h; y++)
1965 draw_line(dr, COORD(0), COORD(y), COORD(w), COORD(y),
1967 for (x = 0; x <= w; x++)
1968 draw_line(dr, COORD(x), COORD(0), COORD(x), COORD(h),
1975 * If we're in the process of animating a move, let's start by
1976 * working out how far the player has moved from their _older_
1980 ap = animtime / ui->anim_length;
1981 player_dist = ap * (dir > 0 ? state : oldstate)->distance_moved;
1988 * Draw the grid contents.
1990 * We count the gems as we go round this loop, for the purposes
1991 * of the status bar. Of course we have a gems counter in the
1992 * game_state already, but if we do the counting in this loop
1993 * then it tracks gems being picked up in a sliding move, and
1994 * updates one by one.
1997 for (y = 0; y < h; y++)
1998 for (x = 0; x < w; x++) {
1999 unsigned short v = (unsigned char)state->grid[y*w+x];
2002 * Special case: if the player is in the process of
2003 * moving over a gem, we draw the gem iff they haven't
2006 if (oldstate && oldstate->grid[y*w+x] != state->grid[y*w+x]) {
2008 * Compute the distance from this square to the
2009 * original player position.
2011 int dist = max(abs(x - oldstate->px), abs(y - oldstate->py));
2014 * If the player has reached here, use the new grid
2015 * element. Otherwise use the old one.
2017 if (player_dist < dist)
2018 v = oldstate->grid[y*w+x];
2020 v = state->grid[y*w+x];
2024 * Special case: erase the mine the dead player is
2025 * sitting on. Only at the end of the move.
2027 if (v == MINE && !oldstate && state->dead &&
2028 x == state->px && y == state->py)
2036 if (ds->grid[y*w+x] != v) {
2037 draw_tile(dr, ds, x, y, v);
2038 ds->grid[y*w+x] = v;
2043 * Gem counter in the status bar. We replace it with
2044 * `COMPLETED!' when it reaches zero ... or rather, when the
2045 * _current state_'s gem counter is zero. (Thus, `Gems: 0' is
2046 * shown between the collection of the last gem and the
2047 * completion of the move animation that did it.)
2049 if (state->dead && (!oldstate || oldstate->dead)) {
2050 sprintf(status, "DEAD!");
2051 } else if (state->gems || (oldstate && oldstate->gems)) {
2053 sprintf(status, "Auto-solver used. ");
2056 sprintf(status + strlen(status), "Gems: %d", gems);
2057 } else if (state->cheated) {
2058 sprintf(status, "Auto-solved.");
2060 sprintf(status, "COMPLETED!");
2062 /* We subtract one from the visible death counter if we're still
2063 * animating the move at the end of which the death took place. */
2064 deaths = ui->deaths;
2065 if (oldstate && ui->just_died) {
2070 sprintf(status + strlen(status), " Deaths: %d", deaths);
2071 status_bar(dr, status);
2074 * Draw the player sprite.
2076 assert(!ds->player_bg_saved);
2077 assert(ds->player_background);
2080 nx = COORD(state->px);
2081 ny = COORD(state->py);
2083 ox = COORD(oldstate->px);
2084 oy = COORD(oldstate->py);
2089 ds->pbgx = ox + ap * (nx - ox);
2090 ds->pbgy = oy + ap * (ny - oy);
2092 blitter_save(dr, ds->player_background, ds->pbgx, ds->pbgy);
2093 draw_player(dr, ds, ds->pbgx, ds->pbgy,
2094 (state->dead && !oldstate),
2095 (!oldstate && state->soln ?
2096 state->soln->list[state->solnpos] : -1));
2097 ds->player_bg_saved = TRUE;
2100 static float game_anim_length(game_state *oldstate, game_state *newstate,
2101 int dir, game_ui *ui)
2105 dist = newstate->distance_moved;
2107 dist = oldstate->distance_moved;
2108 ui->anim_length = sqrt(dist) * BASE_ANIM_LENGTH;
2109 return ui->anim_length;
2112 static float game_flash_length(game_state *oldstate, game_state *newstate,
2113 int dir, game_ui *ui)
2115 if (!oldstate->dead && newstate->dead) {
2116 ui->flashtype = FLASH_DEAD;
2117 return FLASH_LENGTH;
2118 } else if (oldstate->gems && !newstate->gems) {
2119 ui->flashtype = FLASH_WIN;
2120 return FLASH_LENGTH;
2125 static int game_timing_state(game_state *state, game_ui *ui)
2130 static void game_print_size(game_params *params, float *x, float *y)
2134 static void game_print(drawing *dr, game_state *state, int tilesize)
2139 #define thegame inertia
2142 const struct game thegame = {
2143 "Inertia", "games.inertia",
2150 TRUE, game_configure, custom_params,
2158 FALSE, game_text_format,
2166 PREFERRED_TILESIZE, game_compute_size, game_set_size,
2169 game_free_drawstate,
2173 FALSE, FALSE, game_print_size, game_print,
2174 TRUE, /* wants_statusbar */
2175 FALSE, game_timing_state,