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 DX(dir) ( (dir) & 3 ? (((dir) & 7) > 4 ? -1 : +1) : 0 )
36 #define DY(dir) ( DX((dir)+6) )
39 * Lvalue macro which expects x and y to be in range.
41 #define LV_AT(w, h, grid, x, y) ( (grid)[(y)*(w)+(x)] )
44 * Rvalue macro which can cope with x and y being out of range.
46 #define AT(w, h, grid, x, y) ( (x)<0 || (x)>=(w) || (y)<0 || (y)>=(h) ? \
47 WALL : LV_AT(w, h, grid, x, y) )
75 static game_params *default_params(void)
77 game_params *ret = snew(game_params);
85 static void free_params(game_params *params)
90 static game_params *dup_params(game_params *params)
92 game_params *ret = snew(game_params);
93 *ret = *params; /* structure copy */
97 static const struct game_params inertia_presets[] = {
103 static int game_fetch_preset(int i, char **name, game_params **params)
109 if (i < 0 || i >= lenof(inertia_presets))
112 p = inertia_presets[i];
113 ret = dup_params(&p);
114 sprintf(namebuf, "%dx%d", ret->w, ret->h);
115 retname = dupstr(namebuf);
122 static void decode_params(game_params *params, char const *string)
124 params->w = params->h = atoi(string);
125 while (*string && isdigit((unsigned char)*string)) string++;
126 if (*string == 'x') {
128 params->h = atoi(string);
132 static char *encode_params(game_params *params, int full)
136 sprintf(data, "%dx%d", params->w, params->h);
141 static config_item *game_configure(game_params *params)
146 ret = snewn(3, config_item);
148 ret[0].name = "Width";
149 ret[0].type = C_STRING;
150 sprintf(buf, "%d", params->w);
151 ret[0].sval = dupstr(buf);
154 ret[1].name = "Height";
155 ret[1].type = C_STRING;
156 sprintf(buf, "%d", params->h);
157 ret[1].sval = dupstr(buf);
168 static game_params *custom_params(config_item *cfg)
170 game_params *ret = snew(game_params);
172 ret->w = atoi(cfg[0].sval);
173 ret->h = atoi(cfg[1].sval);
178 static char *validate_params(game_params *params, int full)
181 * Avoid completely degenerate cases which only have one
182 * row/column. We probably could generate completable puzzles
183 * of that shape, but they'd be forced to be extremely boring
184 * and at large sizes would take a while to happen upon at
187 if (params->w < 2 || params->h < 2)
188 return "Width and height must both be at least two";
191 * The grid construction algorithm creates 1/5 as many gems as
192 * grid squares, and must create at least one gem to have an
193 * actual puzzle. However, an area-five grid is ruled out by
194 * the above constraint, so the practical minimum is six.
196 if (params->w * params->h < 6)
197 return "Grid area must be at least six squares";
202 /* ----------------------------------------------------------------------
203 * Solver used by grid generator.
206 struct solver_scratch {
207 unsigned char *reachable_from, *reachable_to;
211 static struct solver_scratch *new_scratch(int w, int h)
213 struct solver_scratch *sc = snew(struct solver_scratch);
215 sc->reachable_from = snewn(w * h * DIRECTIONS, unsigned char);
216 sc->reachable_to = snewn(w * h * DIRECTIONS, unsigned char);
217 sc->positions = snewn(w * h * DIRECTIONS, int);
222 static void free_scratch(struct solver_scratch *sc)
227 static int can_go(int w, int h, char *grid,
228 int x1, int y1, int dir1, int x2, int y2, int dir2)
231 * Returns TRUE if we can transition directly from (x1,y1)
232 * going in direction dir1, to (x2,y2) going in direction dir2.
236 * If we're actually in the middle of an unoccupyable square,
237 * we cannot make any move.
239 if (AT(w, h, grid, x1, y1) == WALL ||
240 AT(w, h, grid, x1, y1) == MINE)
244 * If a move is capable of stopping at x1,y1,dir1, and x2,y2 is
245 * the same coordinate as x1,y1, then we can make the
246 * transition (by stopping and changing direction).
248 * For this to be the case, we have to either have a wall
249 * beyond x1,y1,dir1, or have a stop on x1,y1.
251 if (x2 == x1 && y2 == y1 &&
252 (AT(w, h, grid, x1, y1) == STOP ||
253 AT(w, h, grid, x1, y1) == START ||
254 AT(w, h, grid, x1+DX(dir1), y1+DY(dir1)) == WALL))
258 * If a move is capable of continuing here, then x1,y1,dir1 can
259 * move one space further on.
261 if (x2 == x1+DX(dir1) && y2 == y1+DY(dir1) && dir1 == dir2 &&
262 (AT(w, h, grid, x2, y2) == BLANK ||
263 AT(w, h, grid, x2, y2) == GEM ||
264 AT(w, h, grid, x2, y2) == STOP ||
265 AT(w, h, grid, x2, y2) == START))
274 static int find_gem_candidates(int w, int h, char *grid,
275 struct solver_scratch *sc)
279 int sx, sy, gx, gy, gd, pass, possgems;
282 * This function finds all the candidate gem squares, which are
283 * precisely those squares which can be picked up on a loop
284 * from the starting point back to the starting point. Doing
285 * this may involve passing through such a square in the middle
286 * of a move; so simple breadth-first search over the _squares_
287 * of the grid isn't quite adequate, because it might be that
288 * we can only reach a gem from the start by moving over it in
289 * one direction, but can only return to the start if we were
290 * moving over it in another direction.
292 * Instead, we BFS over a space which mentions each grid square
293 * eight times - once for each direction. We also BFS twice:
294 * once to find out what square+direction pairs we can reach
295 * _from_ the start point, and once to find out what pairs we
296 * can reach the start point from. Then a square is reachable
297 * if any of the eight directions for that square has both
301 memset(sc->reachable_from, 0, wh * DIRECTIONS);
302 memset(sc->reachable_to, 0, wh * DIRECTIONS);
305 * Find the starting square.
307 for (sy = 0; sy < h; sy++) {
308 for (sx = 0; sx < w; sx++)
309 if (AT(w, h, grid, sx, sy) == START)
316 for (pass = 0; pass < 2; pass++) {
317 unsigned char *reachable = (pass == 0 ? sc->reachable_from :
319 int sign = (pass == 0 ? +1 : -1);
322 #ifdef SOLVER_DIAGNOSTICS
323 printf("starting pass %d\n", pass);
327 * `head' and `tail' are indices within sc->positions which
328 * track the list of board positions left to process.
331 for (dir = 0; dir < DIRECTIONS; dir++) {
332 int index = (sy*w+sx)*DIRECTIONS+dir;
333 sc->positions[tail++] = index;
334 reachable[index] = TRUE;
335 #ifdef SOLVER_DIAGNOSTICS
336 printf("starting point %d,%d,%d\n", sx, sy, dir);
341 * Now repeatedly pick an element off the list and process
344 while (head < tail) {
345 int index = sc->positions[head++];
346 int dir = index % DIRECTIONS;
347 int x = (index / DIRECTIONS) % w;
348 int y = index / (w * DIRECTIONS);
349 int n, x2, y2, d2, i2;
351 #ifdef SOLVER_DIAGNOSTICS
352 printf("processing point %d,%d,%d\n", x, y, dir);
355 * The places we attempt to switch to here are:
356 * - each possible direction change (all the other
357 * directions in this square)
358 * - one step further in the direction we're going (or
359 * one step back, if we're in the reachable_to pass).
361 for (n = -1; n < DIRECTIONS; n++) {
363 x2 = x + sign * DX(dir);
364 y2 = y + sign * DY(dir);
371 i2 = (y2*w+x2)*DIRECTIONS+d2;
372 if (!reachable[i2]) {
374 #ifdef SOLVER_DIAGNOSTICS
375 printf(" trying point %d,%d,%d", x2, y2, d2);
378 ok = can_go(w, h, grid, x, y, dir, x2, y2, d2);
380 ok = can_go(w, h, grid, x2, y2, d2, x, y, dir);
381 #ifdef SOLVER_DIAGNOSTICS
382 printf(" - %sok\n", ok ? "" : "not ");
385 sc->positions[tail++] = i2;
386 reachable[i2] = TRUE;
394 * And that should be it. Now all we have to do is find the
395 * squares for which there exists _some_ direction such that
396 * the square plus that direction form a tuple which is both
397 * reachable from the start and reachable to the start.
400 for (gy = 0; gy < h; gy++)
401 for (gx = 0; gx < w; gx++)
402 if (AT(w, h, grid, gx, gy) == BLANK) {
403 for (gd = 0; gd < DIRECTIONS; gd++) {
404 int index = (gy*w+gx)*DIRECTIONS+gd;
405 if (sc->reachable_from[index] && sc->reachable_to[index]) {
406 #ifdef SOLVER_DIAGNOSTICS
407 printf("space at %d,%d is reachable via"
408 " direction %d\n", gx, gy, gd);
410 LV_AT(w, h, grid, gx, gy) = POSSGEM;
420 /* ----------------------------------------------------------------------
421 * Grid generation code.
424 static char *gengrid(int w, int h, random_state *rs)
427 char *grid = snewn(wh+1, char);
428 struct solver_scratch *sc = new_scratch(w, h);
429 int maxdist_threshold, tries;
431 maxdist_threshold = 2;
437 int *dist, *list, head, tail, maxdist;
440 * We're going to fill the grid with the five basic piece
441 * types in about 1/5 proportion. For the moment, though,
442 * we leave out the gems, because we'll put those in
443 * _after_ we run the solver to tell us where the viable
447 for (j = 0; j < wh/5; j++)
449 for (j = 0; j < wh/5; j++)
451 for (j = 0; j < wh/5; j++)
457 shuffle(grid, wh, sizeof(*grid), rs);
460 * Find the viable gem locations, and immediately give up
461 * and try again if there aren't enough of them.
463 possgems = find_gem_candidates(w, h, grid, sc);
468 * We _could_ now select wh/5 of the POSSGEMs and set them
469 * to GEM, and have a viable level. However, there's a
470 * chance that a large chunk of the level will turn out to
471 * be unreachable, so first we test for that.
473 * We do this by finding the largest distance from any
474 * square to the nearest POSSGEM, by breadth-first search.
475 * If this is above a critical threshold, we abort and try
478 * (This search is purely geometric, without regard to
479 * walls and long ways round.)
481 dist = sc->positions;
482 list = sc->positions + wh;
483 for (i = 0; i < wh; i++)
486 for (i = 0; i < wh; i++)
487 if (grid[i] == POSSGEM) {
492 while (head < tail) {
496 if (maxdist < dist[pos])
502 for (d = 0; d < DIRECTIONS; d++) {
508 if (x2 >= 0 && x2 < w && y2 >= 0 && y2 < h) {
511 dist[p2] = dist[pos] + 1;
517 assert(head == wh && tail == wh);
520 * Now abandon this grid and go round again if maxdist is
521 * above the required threshold.
523 * We can safely start the threshold as low as 2. As we
524 * accumulate failed generation attempts, we gradually
525 * raise it as we get more desperate.
527 if (maxdist > maxdist_threshold) {
537 * Now our reachable squares are plausibly evenly
538 * distributed over the grid. I'm not actually going to
539 * _enforce_ that I place the gems in such a way as not to
540 * increase that maxdist value; I'm now just going to trust
541 * to the RNG to pick a sensible subset of the POSSGEMs.
544 for (i = 0; i < wh; i++)
545 if (grid[i] == POSSGEM)
547 shuffle(list, j, sizeof(*list), rs);
548 for (i = 0; i < j; i++)
549 grid[list[i]] = (i < wh/5 ? GEM : BLANK);
560 static char *new_game_desc(game_params *params, random_state *rs,
561 char **aux, int interactive)
563 return gengrid(params->w, params->h, rs);
566 static char *validate_desc(game_params *params, char *desc)
568 int w = params->w, h = params->h, wh = w*h;
569 int starts = 0, gems = 0, i;
571 for (i = 0; i < wh; i++) {
573 return "Not enough data to fill grid";
574 if (desc[i] != WALL && desc[i] != START && desc[i] != STOP &&
575 desc[i] != GEM && desc[i] != MINE && desc[i] != BLANK)
576 return "Unrecognised character in game description";
577 if (desc[i] == START)
583 return "Too much data to fill grid";
585 return "No starting square specified";
587 return "More than one starting square specified";
589 return "No gems specified";
594 static game_state *new_game(midend *me, game_params *params, char *desc)
596 int w = params->w, h = params->h, wh = w*h;
598 game_state *state = snew(game_state);
600 state->p = *params; /* structure copy */
602 state->grid = snewn(wh, char);
603 assert(strlen(desc) == wh);
604 memcpy(state->grid, desc, wh);
606 state->px = state->py = -1;
608 for (i = 0; i < wh; i++) {
609 if (state->grid[i] == START) {
610 state->grid[i] = STOP;
613 } else if (state->grid[i] == GEM) {
618 assert(state->gems > 0);
619 assert(state->px >= 0 && state->py >= 0);
621 state->distance_moved = 0;
627 static game_state *dup_game(game_state *state)
629 int w = state->p.w, h = state->p.h, wh = w*h;
630 game_state *ret = snew(game_state);
635 ret->gems = state->gems;
636 ret->grid = snewn(wh, char);
637 ret->distance_moved = state->distance_moved;
639 memcpy(ret->grid, state->grid, wh);
644 static void free_game(game_state *state)
650 static char *solve_game(game_state *state, game_state *currstate,
651 char *aux, char **error)
656 static char *game_text_format(game_state *state)
669 static game_ui *new_ui(game_state *state)
671 game_ui *ui = snew(game_ui);
672 ui->anim_length = 0.0F;
675 ui->just_made_move = FALSE;
676 ui->just_died = FALSE;
680 static void free_ui(game_ui *ui)
685 static char *encode_ui(game_ui *ui)
689 * The deaths counter needs preserving across a serialisation.
691 sprintf(buf, "D%d", ui->deaths);
695 static void decode_ui(game_ui *ui, char *encoding)
698 sscanf(encoding, "D%d%n", &ui->deaths, &p);
701 static void game_changed_state(game_ui *ui, game_state *oldstate,
702 game_state *newstate)
705 * Increment the deaths counter. We only do this if
706 * ui->just_made_move is set (redoing a suicide move doesn't
707 * kill you _again_), and also we only do it if the game isn't
708 * completed (once you're finished, you can play).
710 if (!oldstate->dead && newstate->dead && ui->just_made_move &&
713 ui->just_died = TRUE;
715 ui->just_died = FALSE;
717 ui->just_made_move = FALSE;
720 struct game_drawstate {
724 unsigned short *grid;
725 blitter *player_background;
726 int player_bg_saved, pbgx, pbgy;
729 #define PREFERRED_TILESIZE 32
730 #define TILESIZE (ds->tilesize)
731 #define BORDER (TILESIZE)
732 #define HIGHLIGHT_WIDTH (TILESIZE / 10)
733 #define COORD(x) ( (x) * TILESIZE + BORDER )
734 #define FROMCOORD(x) ( ((x) - BORDER + TILESIZE) / TILESIZE - 1 )
736 static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds,
737 int x, int y, int button)
739 int w = state->p.w, h = state->p.h /*, wh = w*h */;
745 if (button == LEFT_BUTTON) {
747 * Mouse-clicking near the target point (or, more
748 * accurately, in the appropriate octant) is an alternative
749 * way to input moves.
752 if (FROMCOORD(x) != state->px || FROMCOORD(y) != state->py) {
756 dx = FROMCOORD(x) - state->px;
757 dy = FROMCOORD(y) - state->py;
758 /* I pass dx,dy rather than dy,dx so that the octants
759 * end up the right way round. */
760 angle = atan2(dx, -dy);
762 angle = (angle + (PI/8)) / (PI/4);
763 assert(angle > -16.0F);
764 dir = (int)(angle + 16.0F) & 7;
766 } else if (button == CURSOR_UP || button == (MOD_NUM_KEYPAD | '8'))
768 else if (button == CURSOR_DOWN || button == (MOD_NUM_KEYPAD | '2'))
770 else if (button == CURSOR_LEFT || button == (MOD_NUM_KEYPAD | '4'))
772 else if (button == CURSOR_RIGHT || button == (MOD_NUM_KEYPAD | '6'))
774 else if (button == (MOD_NUM_KEYPAD | '7'))
776 else if (button == (MOD_NUM_KEYPAD | '1'))
778 else if (button == (MOD_NUM_KEYPAD | '9'))
780 else if (button == (MOD_NUM_KEYPAD | '3'))
787 * Reject the move if we can't make it at all due to a wall
790 if (AT(w, h, state->grid, state->px+DX(dir), state->py+DY(dir)) == WALL)
794 * Reject the move if we're dead!
800 * Otherwise, we can make the move. All we need to specify is
803 ui->just_made_move = TRUE;
804 sprintf(buf, "%d", dir);
808 static game_state *execute_move(game_state *state, char *move)
810 int w = state->p.w, h = state->p.h /*, wh = w*h */;
811 int dir = atoi(move);
814 if (dir < 0 || dir >= DIRECTIONS)
815 return NULL; /* huh? */
820 if (AT(w, h, state->grid, state->px+DX(dir), state->py+DY(dir)) == WALL)
821 return NULL; /* wall in the way! */
826 ret = dup_game(state);
827 ret->distance_moved = 0;
831 ret->distance_moved++;
833 if (AT(w, h, ret->grid, ret->px, ret->py) == GEM) {
834 LV_AT(w, h, ret->grid, ret->px, ret->py) = BLANK;
838 if (AT(w, h, ret->grid, ret->px, ret->py) == MINE) {
843 if (AT(w, h, ret->grid, ret->px, ret->py) == STOP ||
844 AT(w, h, ret->grid, ret->px+DX(dir),
845 ret->py+DY(dir)) == WALL)
852 /* ----------------------------------------------------------------------
856 static void game_compute_size(game_params *params, int tilesize,
859 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
860 struct { int tilesize; } ads, *ds = &ads;
861 ads.tilesize = tilesize;
863 *x = 2 * BORDER + 1 + params->w * TILESIZE;
864 *y = 2 * BORDER + 1 + params->h * TILESIZE;
867 static void game_set_size(drawing *dr, game_drawstate *ds,
868 game_params *params, int tilesize)
870 ds->tilesize = tilesize;
872 assert(!ds->player_bg_saved);
874 if (ds->player_background)
875 blitter_free(dr, ds->player_background);
876 ds->player_background = blitter_new(dr, TILESIZE, TILESIZE);
879 static float *game_colours(frontend *fe, game_state *state, int *ncolours)
881 float *ret = snewn(3 * NCOLOURS, float);
884 game_mkhighlight(fe, ret, COL_BACKGROUND, COL_HIGHLIGHT, COL_LOWLIGHT);
886 ret[COL_OUTLINE * 3 + 0] = 0.0F;
887 ret[COL_OUTLINE * 3 + 1] = 0.0F;
888 ret[COL_OUTLINE * 3 + 2] = 0.0F;
890 ret[COL_PLAYER * 3 + 0] = 0.0F;
891 ret[COL_PLAYER * 3 + 1] = 1.0F;
892 ret[COL_PLAYER * 3 + 2] = 0.0F;
894 ret[COL_DEAD_PLAYER * 3 + 0] = 1.0F;
895 ret[COL_DEAD_PLAYER * 3 + 1] = 0.0F;
896 ret[COL_DEAD_PLAYER * 3 + 2] = 0.0F;
898 ret[COL_MINE * 3 + 0] = 0.0F;
899 ret[COL_MINE * 3 + 1] = 0.0F;
900 ret[COL_MINE * 3 + 2] = 0.0F;
902 ret[COL_GEM * 3 + 0] = 0.6F;
903 ret[COL_GEM * 3 + 1] = 1.0F;
904 ret[COL_GEM * 3 + 2] = 1.0F;
906 for (i = 0; i < 3; i++) {
907 ret[COL_WALL * 3 + i] = (3 * ret[COL_BACKGROUND * 3 + i] +
908 1 * ret[COL_HIGHLIGHT * 3 + i]) / 4;
911 *ncolours = NCOLOURS;
915 static game_drawstate *game_new_drawstate(drawing *dr, game_state *state)
917 int w = state->p.w, h = state->p.h, wh = w*h;
918 struct game_drawstate *ds = snew(struct game_drawstate);
923 /* We can't allocate the blitter rectangle for the player background
924 * until we know what size to make it. */
925 ds->player_background = NULL;
926 ds->player_bg_saved = FALSE;
927 ds->pbgx = ds->pbgy = -1;
929 ds->p = state->p; /* structure copy */
931 ds->grid = snewn(wh, unsigned short);
932 for (i = 0; i < wh; i++)
933 ds->grid[i] = UNDRAWN;
938 static void game_free_drawstate(drawing *dr, game_drawstate *ds)
944 static void draw_player(drawing *dr, game_drawstate *ds, int x, int y,
948 int coords[DIRECTIONS*4];
951 for (d = 0; d < DIRECTIONS; d++) {
952 float x1, y1, x2, y2, x3, y3, len;
956 len = sqrt(x1*x1+y1*y1); x1 /= len; y1 /= len;
960 len = sqrt(x3*x3+y3*y3); x3 /= len; y3 /= len;
965 coords[d*4+0] = x + TILESIZE/2 + (int)((TILESIZE*3/7) * x1);
966 coords[d*4+1] = y + TILESIZE/2 + (int)((TILESIZE*3/7) * y1);
967 coords[d*4+2] = x + TILESIZE/2 + (int)((TILESIZE*3/7) * x2);
968 coords[d*4+3] = y + TILESIZE/2 + (int)((TILESIZE*3/7) * y2);
970 draw_polygon(dr, coords, DIRECTIONS*2, COL_DEAD_PLAYER, COL_OUTLINE);
972 draw_circle(dr, x + TILESIZE/2, y + TILESIZE/2,
973 TILESIZE/3, COL_PLAYER, COL_OUTLINE);
975 draw_update(dr, x, y, TILESIZE, TILESIZE);
978 #define FLASH_DEAD 0x100
979 #define FLASH_WIN 0x200
980 #define FLASH_MASK 0x300
982 static void draw_tile(drawing *dr, game_drawstate *ds, int x, int y, int v)
984 int tx = COORD(x), ty = COORD(y);
985 int bg = (v & FLASH_DEAD ? COL_DEAD_PLAYER :
986 v & FLASH_WIN ? COL_HIGHLIGHT : COL_BACKGROUND);
990 clip(dr, tx+1, ty+1, TILESIZE-1, TILESIZE-1);
991 draw_rect(dr, tx+1, ty+1, TILESIZE-1, TILESIZE-1, bg);
996 coords[0] = tx + TILESIZE;
997 coords[1] = ty + TILESIZE;
998 coords[2] = tx + TILESIZE;
1001 coords[5] = ty + TILESIZE;
1002 draw_polygon(dr, coords, 3, COL_LOWLIGHT, COL_LOWLIGHT);
1006 draw_polygon(dr, coords, 3, COL_HIGHLIGHT, COL_HIGHLIGHT);
1008 draw_rect(dr, tx + 1 + HIGHLIGHT_WIDTH, ty + 1 + HIGHLIGHT_WIDTH,
1009 TILESIZE - 2*HIGHLIGHT_WIDTH,
1010 TILESIZE - 2*HIGHLIGHT_WIDTH, COL_WALL);
1011 } else if (v == MINE) {
1012 int cx = tx + TILESIZE / 2;
1013 int cy = ty + TILESIZE / 2;
1014 int r = TILESIZE / 2 - 3;
1016 int xdx = 1, xdy = 0, ydx = 0, ydy = 1;
1019 for (i = 0; i < 4*5*2; i += 5*2) {
1020 coords[i+2*0+0] = cx - r/6*xdx + r*4/5*ydx;
1021 coords[i+2*0+1] = cy - r/6*xdy + r*4/5*ydy;
1022 coords[i+2*1+0] = cx - r/6*xdx + r*ydx;
1023 coords[i+2*1+1] = cy - r/6*xdy + r*ydy;
1024 coords[i+2*2+0] = cx + r/6*xdx + r*ydx;
1025 coords[i+2*2+1] = cy + r/6*xdy + r*ydy;
1026 coords[i+2*3+0] = cx + r/6*xdx + r*4/5*ydx;
1027 coords[i+2*3+1] = cy + r/6*xdy + r*4/5*ydy;
1028 coords[i+2*4+0] = cx + r*3/5*xdx + r*3/5*ydx;
1029 coords[i+2*4+1] = cy + r*3/5*xdy + r*3/5*ydy;
1039 draw_polygon(dr, coords, 5*4, COL_MINE, COL_MINE);
1041 draw_rect(dr, cx-r/3, cy-r/3, r/3, r/4, COL_HIGHLIGHT);
1042 } else if (v == STOP) {
1043 draw_circle(dr, tx + TILESIZE/2, ty + TILESIZE/2,
1044 TILESIZE*3/7, -1, COL_OUTLINE);
1045 draw_rect(dr, tx + TILESIZE*3/7, ty+1,
1046 TILESIZE - 2*(TILESIZE*3/7) + 1, TILESIZE-1, bg);
1047 draw_rect(dr, tx+1, ty + TILESIZE*3/7,
1048 TILESIZE-1, TILESIZE - 2*(TILESIZE*3/7) + 1, bg);
1049 } else if (v == GEM) {
1052 coords[0] = tx+TILESIZE/2;
1053 coords[1] = ty+TILESIZE*1/7;
1054 coords[2] = tx+TILESIZE*1/7;
1055 coords[3] = ty+TILESIZE/2;
1056 coords[4] = tx+TILESIZE/2;
1057 coords[5] = ty+TILESIZE-TILESIZE*1/7;
1058 coords[6] = tx+TILESIZE-TILESIZE*1/7;
1059 coords[7] = ty+TILESIZE/2;
1061 draw_polygon(dr, coords, 4, COL_GEM, COL_OUTLINE);
1065 draw_update(dr, tx, ty, TILESIZE, TILESIZE);
1068 #define BASE_ANIM_LENGTH 0.1F
1069 #define FLASH_LENGTH 0.3F
1071 static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate,
1072 game_state *state, int dir, game_ui *ui,
1073 float animtime, float flashtime)
1075 int w = state->p.w, h = state->p.h /*, wh = w*h */;
1084 !((int)(flashtime * 3 / FLASH_LENGTH) % 2))
1085 flashtype = ui->flashtype;
1090 * Erase the player sprite.
1092 if (ds->player_bg_saved) {
1093 assert(ds->player_background);
1094 blitter_load(dr, ds->player_background, ds->pbgx, ds->pbgy);
1095 draw_update(dr, ds->pbgx, ds->pbgy, TILESIZE, TILESIZE);
1096 ds->player_bg_saved = FALSE;
1100 * Initialise a fresh drawstate.
1106 * Blank out the window initially.
1108 game_compute_size(&ds->p, TILESIZE, &wid, &ht);
1109 draw_rect(dr, 0, 0, wid, ht, COL_BACKGROUND);
1110 draw_update(dr, 0, 0, wid, ht);
1113 * Draw the grid lines.
1115 for (y = 0; y <= h; y++)
1116 draw_line(dr, COORD(0), COORD(y), COORD(w), COORD(y),
1118 for (x = 0; x <= w; x++)
1119 draw_line(dr, COORD(x), COORD(0), COORD(x), COORD(h),
1126 * If we're in the process of animating a move, let's start by
1127 * working out how far the player has moved from their _older_
1131 ap = animtime / ui->anim_length;
1132 player_dist = ap * (dir > 0 ? state : oldstate)->distance_moved;
1139 * Draw the grid contents.
1141 * We count the gems as we go round this loop, for the purposes
1142 * of the status bar. Of course we have a gems counter in the
1143 * game_state already, but if we do the counting in this loop
1144 * then it tracks gems being picked up in a sliding move, and
1145 * updates one by one.
1148 for (y = 0; y < h; y++)
1149 for (x = 0; x < w; x++) {
1150 unsigned short v = (unsigned char)state->grid[y*w+x];
1153 * Special case: if the player is in the process of
1154 * moving over a gem, we draw the gem iff they haven't
1157 if (oldstate && oldstate->grid[y*w+x] != state->grid[y*w+x]) {
1159 * Compute the distance from this square to the
1160 * original player position.
1162 int dist = max(abs(x - oldstate->px), abs(y - oldstate->py));
1165 * If the player has reached here, use the new grid
1166 * element. Otherwise use the old one.
1168 if (player_dist < dist)
1169 v = oldstate->grid[y*w+x];
1171 v = state->grid[y*w+x];
1175 * Special case: erase the mine the dead player is
1176 * sitting on. Only at the end of the move.
1178 if (v == MINE && !oldstate && state->dead &&
1179 x == state->px && y == state->py)
1187 if (ds->grid[y*w+x] != v) {
1188 draw_tile(dr, ds, x, y, v);
1189 ds->grid[y*w+x] = v;
1194 * Gem counter in the status bar. We replace it with
1195 * `COMPLETED!' when it reaches zero ... or rather, when the
1196 * _current state_'s gem counter is zero. (Thus, `Gems: 0' is
1197 * shown between the collection of the last gem and the
1198 * completion of the move animation that did it.)
1200 if (state->dead && (!oldstate || oldstate->dead))
1201 sprintf(status, "DEAD!");
1202 else if (state->gems || (oldstate && oldstate->gems))
1203 sprintf(status, "Gems: %d", gems);
1205 sprintf(status, "COMPLETED!");
1206 /* We subtract one from the visible death counter if we're still
1207 * animating the move at the end of which the death took place. */
1208 deaths = ui->deaths;
1209 if (oldstate && ui->just_died) {
1214 sprintf(status + strlen(status), " Deaths: %d", deaths);
1215 status_bar(dr, status);
1218 * Draw the player sprite.
1220 assert(!ds->player_bg_saved);
1221 assert(ds->player_background);
1224 nx = COORD(state->px);
1225 ny = COORD(state->py);
1227 ox = COORD(oldstate->px);
1228 oy = COORD(oldstate->py);
1233 ds->pbgx = ox + ap * (nx - ox);
1234 ds->pbgy = oy + ap * (ny - oy);
1236 blitter_save(dr, ds->player_background, ds->pbgx, ds->pbgy);
1237 draw_player(dr, ds, ds->pbgx, ds->pbgy, (state->dead && !oldstate));
1238 ds->player_bg_saved = TRUE;
1241 static float game_anim_length(game_state *oldstate, game_state *newstate,
1242 int dir, game_ui *ui)
1246 dist = newstate->distance_moved;
1248 dist = oldstate->distance_moved;
1249 ui->anim_length = sqrt(dist) * BASE_ANIM_LENGTH;
1250 return ui->anim_length;
1253 static float game_flash_length(game_state *oldstate, game_state *newstate,
1254 int dir, game_ui *ui)
1256 if (!oldstate->dead && newstate->dead) {
1257 ui->flashtype = FLASH_DEAD;
1258 return FLASH_LENGTH;
1259 } else if (oldstate->gems && !newstate->gems) {
1260 ui->flashtype = FLASH_WIN;
1261 return FLASH_LENGTH;
1266 static int game_wants_statusbar(void)
1271 static int game_timing_state(game_state *state, game_ui *ui)
1276 static void game_print_size(game_params *params, float *x, float *y)
1280 static void game_print(drawing *dr, game_state *state, int tilesize)
1285 #define thegame inertia
1288 const struct game thegame = {
1289 "Inertia", "games.inertia",
1296 TRUE, game_configure, custom_params,
1304 FALSE, game_text_format,
1312 PREFERRED_TILESIZE, game_compute_size, game_set_size,
1315 game_free_drawstate,
1319 FALSE, FALSE, game_print_size, game_print,
1320 game_wants_statusbar,
1321 FALSE, game_timing_state,
1322 0, /* mouse_priorities */