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 sx = -1; /* placate optimiser */
308 for (sy = 0; sy < h; sy++) {
309 for (sx = 0; sx < w; sx++)
310 if (AT(w, h, grid, sx, sy) == START)
317 for (pass = 0; pass < 2; pass++) {
318 unsigned char *reachable = (pass == 0 ? sc->reachable_from :
320 int sign = (pass == 0 ? +1 : -1);
323 #ifdef SOLVER_DIAGNOSTICS
324 printf("starting pass %d\n", pass);
328 * `head' and `tail' are indices within sc->positions which
329 * track the list of board positions left to process.
332 for (dir = 0; dir < DIRECTIONS; dir++) {
333 int index = (sy*w+sx)*DIRECTIONS+dir;
334 sc->positions[tail++] = index;
335 reachable[index] = TRUE;
336 #ifdef SOLVER_DIAGNOSTICS
337 printf("starting point %d,%d,%d\n", sx, sy, dir);
342 * Now repeatedly pick an element off the list and process
345 while (head < tail) {
346 int index = sc->positions[head++];
347 int dir = index % DIRECTIONS;
348 int x = (index / DIRECTIONS) % w;
349 int y = index / (w * DIRECTIONS);
350 int n, x2, y2, d2, i2;
352 #ifdef SOLVER_DIAGNOSTICS
353 printf("processing point %d,%d,%d\n", x, y, dir);
356 * The places we attempt to switch to here are:
357 * - each possible direction change (all the other
358 * directions in this square)
359 * - one step further in the direction we're going (or
360 * one step back, if we're in the reachable_to pass).
362 for (n = -1; n < DIRECTIONS; n++) {
364 x2 = x + sign * DX(dir);
365 y2 = y + sign * DY(dir);
372 i2 = (y2*w+x2)*DIRECTIONS+d2;
373 if (x2 >= 0 && x2 < w &&
377 #ifdef SOLVER_DIAGNOSTICS
378 printf(" trying point %d,%d,%d", x2, y2, d2);
381 ok = can_go(w, h, grid, x, y, dir, x2, y2, d2);
383 ok = can_go(w, h, grid, x2, y2, d2, x, y, dir);
384 #ifdef SOLVER_DIAGNOSTICS
385 printf(" - %sok\n", ok ? "" : "not ");
388 sc->positions[tail++] = i2;
389 reachable[i2] = TRUE;
397 * And that should be it. Now all we have to do is find the
398 * squares for which there exists _some_ direction such that
399 * the square plus that direction form a tuple which is both
400 * reachable from the start and reachable to the start.
403 for (gy = 0; gy < h; gy++)
404 for (gx = 0; gx < w; gx++)
405 if (AT(w, h, grid, gx, gy) == BLANK) {
406 for (gd = 0; gd < DIRECTIONS; gd++) {
407 int index = (gy*w+gx)*DIRECTIONS+gd;
408 if (sc->reachable_from[index] && sc->reachable_to[index]) {
409 #ifdef SOLVER_DIAGNOSTICS
410 printf("space at %d,%d is reachable via"
411 " direction %d\n", gx, gy, gd);
413 LV_AT(w, h, grid, gx, gy) = POSSGEM;
423 /* ----------------------------------------------------------------------
424 * Grid generation code.
427 static char *gengrid(int w, int h, random_state *rs)
430 char *grid = snewn(wh+1, char);
431 struct solver_scratch *sc = new_scratch(w, h);
432 int maxdist_threshold, tries;
434 maxdist_threshold = 2;
440 int *dist, *list, head, tail, maxdist;
443 * We're going to fill the grid with the five basic piece
444 * types in about 1/5 proportion. For the moment, though,
445 * we leave out the gems, because we'll put those in
446 * _after_ we run the solver to tell us where the viable
450 for (j = 0; j < wh/5; j++)
452 for (j = 0; j < wh/5; j++)
454 for (j = 0; j < wh/5; j++)
460 shuffle(grid, wh, sizeof(*grid), rs);
463 * Find the viable gem locations, and immediately give up
464 * and try again if there aren't enough of them.
466 possgems = find_gem_candidates(w, h, grid, sc);
471 * We _could_ now select wh/5 of the POSSGEMs and set them
472 * to GEM, and have a viable level. However, there's a
473 * chance that a large chunk of the level will turn out to
474 * be unreachable, so first we test for that.
476 * We do this by finding the largest distance from any
477 * square to the nearest POSSGEM, by breadth-first search.
478 * If this is above a critical threshold, we abort and try
481 * (This search is purely geometric, without regard to
482 * walls and long ways round.)
484 dist = sc->positions;
485 list = sc->positions + wh;
486 for (i = 0; i < wh; i++)
489 for (i = 0; i < wh; i++)
490 if (grid[i] == POSSGEM) {
495 while (head < tail) {
499 if (maxdist < dist[pos])
505 for (d = 0; d < DIRECTIONS; d++) {
511 if (x2 >= 0 && x2 < w && y2 >= 0 && y2 < h) {
514 dist[p2] = dist[pos] + 1;
520 assert(head == wh && tail == wh);
523 * Now abandon this grid and go round again if maxdist is
524 * above the required threshold.
526 * We can safely start the threshold as low as 2. As we
527 * accumulate failed generation attempts, we gradually
528 * raise it as we get more desperate.
530 if (maxdist > maxdist_threshold) {
540 * Now our reachable squares are plausibly evenly
541 * distributed over the grid. I'm not actually going to
542 * _enforce_ that I place the gems in such a way as not to
543 * increase that maxdist value; I'm now just going to trust
544 * to the RNG to pick a sensible subset of the POSSGEMs.
547 for (i = 0; i < wh; i++)
548 if (grid[i] == POSSGEM)
550 shuffle(list, j, sizeof(*list), rs);
551 for (i = 0; i < j; i++)
552 grid[list[i]] = (i < wh/5 ? GEM : BLANK);
563 static char *new_game_desc(game_params *params, random_state *rs,
564 char **aux, int interactive)
566 return gengrid(params->w, params->h, rs);
569 static char *validate_desc(game_params *params, char *desc)
571 int w = params->w, h = params->h, wh = w*h;
572 int starts = 0, gems = 0, i;
574 for (i = 0; i < wh; i++) {
576 return "Not enough data to fill grid";
577 if (desc[i] != WALL && desc[i] != START && desc[i] != STOP &&
578 desc[i] != GEM && desc[i] != MINE && desc[i] != BLANK)
579 return "Unrecognised character in game description";
580 if (desc[i] == START)
586 return "Too much data to fill grid";
588 return "No starting square specified";
590 return "More than one starting square specified";
592 return "No gems specified";
597 static game_state *new_game(midend *me, game_params *params, char *desc)
599 int w = params->w, h = params->h, wh = w*h;
601 game_state *state = snew(game_state);
603 state->p = *params; /* structure copy */
605 state->grid = snewn(wh, char);
606 assert(strlen(desc) == wh);
607 memcpy(state->grid, desc, wh);
609 state->px = state->py = -1;
611 for (i = 0; i < wh; i++) {
612 if (state->grid[i] == START) {
613 state->grid[i] = STOP;
616 } else if (state->grid[i] == GEM) {
621 assert(state->gems > 0);
622 assert(state->px >= 0 && state->py >= 0);
624 state->distance_moved = 0;
630 static game_state *dup_game(game_state *state)
632 int w = state->p.w, h = state->p.h, wh = w*h;
633 game_state *ret = snew(game_state);
638 ret->gems = state->gems;
639 ret->grid = snewn(wh, char);
640 ret->distance_moved = state->distance_moved;
642 memcpy(ret->grid, state->grid, wh);
647 static void free_game(game_state *state)
653 static char *solve_game(game_state *state, game_state *currstate,
654 char *aux, char **error)
659 static char *game_text_format(game_state *state)
672 static game_ui *new_ui(game_state *state)
674 game_ui *ui = snew(game_ui);
675 ui->anim_length = 0.0F;
678 ui->just_made_move = FALSE;
679 ui->just_died = FALSE;
683 static void free_ui(game_ui *ui)
688 static char *encode_ui(game_ui *ui)
692 * The deaths counter needs preserving across a serialisation.
694 sprintf(buf, "D%d", ui->deaths);
698 static void decode_ui(game_ui *ui, char *encoding)
701 sscanf(encoding, "D%d%n", &ui->deaths, &p);
704 static void game_changed_state(game_ui *ui, game_state *oldstate,
705 game_state *newstate)
708 * Increment the deaths counter. We only do this if
709 * ui->just_made_move is set (redoing a suicide move doesn't
710 * kill you _again_), and also we only do it if the game isn't
711 * completed (once you're finished, you can play).
713 if (!oldstate->dead && newstate->dead && ui->just_made_move &&
716 ui->just_died = TRUE;
718 ui->just_died = FALSE;
720 ui->just_made_move = FALSE;
723 struct game_drawstate {
727 unsigned short *grid;
728 blitter *player_background;
729 int player_bg_saved, pbgx, pbgy;
732 #define PREFERRED_TILESIZE 32
733 #define TILESIZE (ds->tilesize)
734 #define BORDER (TILESIZE)
735 #define HIGHLIGHT_WIDTH (TILESIZE / 10)
736 #define COORD(x) ( (x) * TILESIZE + BORDER )
737 #define FROMCOORD(x) ( ((x) - BORDER + TILESIZE) / TILESIZE - 1 )
739 static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds,
740 int x, int y, int button)
742 int w = state->p.w, h = state->p.h /*, wh = w*h */;
748 if (button == LEFT_BUTTON) {
750 * Mouse-clicking near the target point (or, more
751 * accurately, in the appropriate octant) is an alternative
752 * way to input moves.
755 if (FROMCOORD(x) != state->px || FROMCOORD(y) != state->py) {
759 dx = FROMCOORD(x) - state->px;
760 dy = FROMCOORD(y) - state->py;
761 /* I pass dx,dy rather than dy,dx so that the octants
762 * end up the right way round. */
763 angle = atan2(dx, -dy);
765 angle = (angle + (PI/8)) / (PI/4);
766 assert(angle > -16.0F);
767 dir = (int)(angle + 16.0F) & 7;
769 } else if (button == CURSOR_UP || button == (MOD_NUM_KEYPAD | '8'))
771 else if (button == CURSOR_DOWN || button == (MOD_NUM_KEYPAD | '2'))
773 else if (button == CURSOR_LEFT || button == (MOD_NUM_KEYPAD | '4'))
775 else if (button == CURSOR_RIGHT || button == (MOD_NUM_KEYPAD | '6'))
777 else if (button == (MOD_NUM_KEYPAD | '7'))
779 else if (button == (MOD_NUM_KEYPAD | '1'))
781 else if (button == (MOD_NUM_KEYPAD | '9'))
783 else if (button == (MOD_NUM_KEYPAD | '3'))
790 * Reject the move if we can't make it at all due to a wall
793 if (AT(w, h, state->grid, state->px+DX(dir), state->py+DY(dir)) == WALL)
797 * Reject the move if we're dead!
803 * Otherwise, we can make the move. All we need to specify is
806 ui->just_made_move = TRUE;
807 sprintf(buf, "%d", dir);
811 static game_state *execute_move(game_state *state, char *move)
813 int w = state->p.w, h = state->p.h /*, wh = w*h */;
814 int dir = atoi(move);
817 if (dir < 0 || dir >= DIRECTIONS)
818 return NULL; /* huh? */
823 if (AT(w, h, state->grid, state->px+DX(dir), state->py+DY(dir)) == WALL)
824 return NULL; /* wall in the way! */
829 ret = dup_game(state);
830 ret->distance_moved = 0;
834 ret->distance_moved++;
836 if (AT(w, h, ret->grid, ret->px, ret->py) == GEM) {
837 LV_AT(w, h, ret->grid, ret->px, ret->py) = BLANK;
841 if (AT(w, h, ret->grid, ret->px, ret->py) == MINE) {
846 if (AT(w, h, ret->grid, ret->px, ret->py) == STOP ||
847 AT(w, h, ret->grid, ret->px+DX(dir),
848 ret->py+DY(dir)) == WALL)
855 /* ----------------------------------------------------------------------
859 static void game_compute_size(game_params *params, int tilesize,
862 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
863 struct { int tilesize; } ads, *ds = &ads;
864 ads.tilesize = tilesize;
866 *x = 2 * BORDER + 1 + params->w * TILESIZE;
867 *y = 2 * BORDER + 1 + params->h * TILESIZE;
870 static void game_set_size(drawing *dr, game_drawstate *ds,
871 game_params *params, int tilesize)
873 ds->tilesize = tilesize;
875 assert(!ds->player_bg_saved);
877 if (ds->player_background)
878 blitter_free(dr, ds->player_background);
879 ds->player_background = blitter_new(dr, TILESIZE, TILESIZE);
882 static float *game_colours(frontend *fe, game_state *state, int *ncolours)
884 float *ret = snewn(3 * NCOLOURS, float);
887 game_mkhighlight(fe, ret, COL_BACKGROUND, COL_HIGHLIGHT, COL_LOWLIGHT);
889 ret[COL_OUTLINE * 3 + 0] = 0.0F;
890 ret[COL_OUTLINE * 3 + 1] = 0.0F;
891 ret[COL_OUTLINE * 3 + 2] = 0.0F;
893 ret[COL_PLAYER * 3 + 0] = 0.0F;
894 ret[COL_PLAYER * 3 + 1] = 1.0F;
895 ret[COL_PLAYER * 3 + 2] = 0.0F;
897 ret[COL_DEAD_PLAYER * 3 + 0] = 1.0F;
898 ret[COL_DEAD_PLAYER * 3 + 1] = 0.0F;
899 ret[COL_DEAD_PLAYER * 3 + 2] = 0.0F;
901 ret[COL_MINE * 3 + 0] = 0.0F;
902 ret[COL_MINE * 3 + 1] = 0.0F;
903 ret[COL_MINE * 3 + 2] = 0.0F;
905 ret[COL_GEM * 3 + 0] = 0.6F;
906 ret[COL_GEM * 3 + 1] = 1.0F;
907 ret[COL_GEM * 3 + 2] = 1.0F;
909 for (i = 0; i < 3; i++) {
910 ret[COL_WALL * 3 + i] = (3 * ret[COL_BACKGROUND * 3 + i] +
911 1 * ret[COL_HIGHLIGHT * 3 + i]) / 4;
914 *ncolours = NCOLOURS;
918 static game_drawstate *game_new_drawstate(drawing *dr, game_state *state)
920 int w = state->p.w, h = state->p.h, wh = w*h;
921 struct game_drawstate *ds = snew(struct game_drawstate);
926 /* We can't allocate the blitter rectangle for the player background
927 * until we know what size to make it. */
928 ds->player_background = NULL;
929 ds->player_bg_saved = FALSE;
930 ds->pbgx = ds->pbgy = -1;
932 ds->p = state->p; /* structure copy */
934 ds->grid = snewn(wh, unsigned short);
935 for (i = 0; i < wh; i++)
936 ds->grid[i] = UNDRAWN;
941 static void game_free_drawstate(drawing *dr, game_drawstate *ds)
947 static void draw_player(drawing *dr, game_drawstate *ds, int x, int y,
951 int coords[DIRECTIONS*4];
954 for (d = 0; d < DIRECTIONS; d++) {
955 float x1, y1, x2, y2, x3, y3, len;
959 len = sqrt(x1*x1+y1*y1); x1 /= len; y1 /= len;
963 len = sqrt(x3*x3+y3*y3); x3 /= len; y3 /= len;
968 coords[d*4+0] = x + TILESIZE/2 + (int)((TILESIZE*3/7) * x1);
969 coords[d*4+1] = y + TILESIZE/2 + (int)((TILESIZE*3/7) * y1);
970 coords[d*4+2] = x + TILESIZE/2 + (int)((TILESIZE*3/7) * x2);
971 coords[d*4+3] = y + TILESIZE/2 + (int)((TILESIZE*3/7) * y2);
973 draw_polygon(dr, coords, DIRECTIONS*2, COL_DEAD_PLAYER, COL_OUTLINE);
975 draw_circle(dr, x + TILESIZE/2, y + TILESIZE/2,
976 TILESIZE/3, COL_PLAYER, COL_OUTLINE);
978 draw_update(dr, x, y, TILESIZE, TILESIZE);
981 #define FLASH_DEAD 0x100
982 #define FLASH_WIN 0x200
983 #define FLASH_MASK 0x300
985 static void draw_tile(drawing *dr, game_drawstate *ds, int x, int y, int v)
987 int tx = COORD(x), ty = COORD(y);
988 int bg = (v & FLASH_DEAD ? COL_DEAD_PLAYER :
989 v & FLASH_WIN ? COL_HIGHLIGHT : COL_BACKGROUND);
993 clip(dr, tx+1, ty+1, TILESIZE-1, TILESIZE-1);
994 draw_rect(dr, tx+1, ty+1, TILESIZE-1, TILESIZE-1, bg);
999 coords[0] = tx + TILESIZE;
1000 coords[1] = ty + TILESIZE;
1001 coords[2] = tx + TILESIZE;
1004 coords[5] = ty + TILESIZE;
1005 draw_polygon(dr, coords, 3, COL_LOWLIGHT, COL_LOWLIGHT);
1009 draw_polygon(dr, coords, 3, COL_HIGHLIGHT, COL_HIGHLIGHT);
1011 draw_rect(dr, tx + 1 + HIGHLIGHT_WIDTH, ty + 1 + HIGHLIGHT_WIDTH,
1012 TILESIZE - 2*HIGHLIGHT_WIDTH,
1013 TILESIZE - 2*HIGHLIGHT_WIDTH, COL_WALL);
1014 } else if (v == MINE) {
1015 int cx = tx + TILESIZE / 2;
1016 int cy = ty + TILESIZE / 2;
1017 int r = TILESIZE / 2 - 3;
1019 int xdx = 1, xdy = 0, ydx = 0, ydy = 1;
1022 for (i = 0; i < 4*5*2; i += 5*2) {
1023 coords[i+2*0+0] = cx - r/6*xdx + r*4/5*ydx;
1024 coords[i+2*0+1] = cy - r/6*xdy + r*4/5*ydy;
1025 coords[i+2*1+0] = cx - r/6*xdx + r*ydx;
1026 coords[i+2*1+1] = cy - r/6*xdy + r*ydy;
1027 coords[i+2*2+0] = cx + r/6*xdx + r*ydx;
1028 coords[i+2*2+1] = cy + r/6*xdy + r*ydy;
1029 coords[i+2*3+0] = cx + r/6*xdx + r*4/5*ydx;
1030 coords[i+2*3+1] = cy + r/6*xdy + r*4/5*ydy;
1031 coords[i+2*4+0] = cx + r*3/5*xdx + r*3/5*ydx;
1032 coords[i+2*4+1] = cy + r*3/5*xdy + r*3/5*ydy;
1042 draw_polygon(dr, coords, 5*4, COL_MINE, COL_MINE);
1044 draw_rect(dr, cx-r/3, cy-r/3, r/3, r/4, COL_HIGHLIGHT);
1045 } else if (v == STOP) {
1046 draw_circle(dr, tx + TILESIZE/2, ty + TILESIZE/2,
1047 TILESIZE*3/7, -1, COL_OUTLINE);
1048 draw_rect(dr, tx + TILESIZE*3/7, ty+1,
1049 TILESIZE - 2*(TILESIZE*3/7) + 1, TILESIZE-1, bg);
1050 draw_rect(dr, tx+1, ty + TILESIZE*3/7,
1051 TILESIZE-1, TILESIZE - 2*(TILESIZE*3/7) + 1, bg);
1052 } else if (v == GEM) {
1055 coords[0] = tx+TILESIZE/2;
1056 coords[1] = ty+TILESIZE*1/7;
1057 coords[2] = tx+TILESIZE*1/7;
1058 coords[3] = ty+TILESIZE/2;
1059 coords[4] = tx+TILESIZE/2;
1060 coords[5] = ty+TILESIZE-TILESIZE*1/7;
1061 coords[6] = tx+TILESIZE-TILESIZE*1/7;
1062 coords[7] = ty+TILESIZE/2;
1064 draw_polygon(dr, coords, 4, COL_GEM, COL_OUTLINE);
1068 draw_update(dr, tx, ty, TILESIZE, TILESIZE);
1071 #define BASE_ANIM_LENGTH 0.1F
1072 #define FLASH_LENGTH 0.3F
1074 static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate,
1075 game_state *state, int dir, game_ui *ui,
1076 float animtime, float flashtime)
1078 int w = state->p.w, h = state->p.h /*, wh = w*h */;
1087 !((int)(flashtime * 3 / FLASH_LENGTH) % 2))
1088 flashtype = ui->flashtype;
1093 * Erase the player sprite.
1095 if (ds->player_bg_saved) {
1096 assert(ds->player_background);
1097 blitter_load(dr, ds->player_background, ds->pbgx, ds->pbgy);
1098 draw_update(dr, ds->pbgx, ds->pbgy, TILESIZE, TILESIZE);
1099 ds->player_bg_saved = FALSE;
1103 * Initialise a fresh drawstate.
1109 * Blank out the window initially.
1111 game_compute_size(&ds->p, TILESIZE, &wid, &ht);
1112 draw_rect(dr, 0, 0, wid, ht, COL_BACKGROUND);
1113 draw_update(dr, 0, 0, wid, ht);
1116 * Draw the grid lines.
1118 for (y = 0; y <= h; y++)
1119 draw_line(dr, COORD(0), COORD(y), COORD(w), COORD(y),
1121 for (x = 0; x <= w; x++)
1122 draw_line(dr, COORD(x), COORD(0), COORD(x), COORD(h),
1129 * If we're in the process of animating a move, let's start by
1130 * working out how far the player has moved from their _older_
1134 ap = animtime / ui->anim_length;
1135 player_dist = ap * (dir > 0 ? state : oldstate)->distance_moved;
1142 * Draw the grid contents.
1144 * We count the gems as we go round this loop, for the purposes
1145 * of the status bar. Of course we have a gems counter in the
1146 * game_state already, but if we do the counting in this loop
1147 * then it tracks gems being picked up in a sliding move, and
1148 * updates one by one.
1151 for (y = 0; y < h; y++)
1152 for (x = 0; x < w; x++) {
1153 unsigned short v = (unsigned char)state->grid[y*w+x];
1156 * Special case: if the player is in the process of
1157 * moving over a gem, we draw the gem iff they haven't
1160 if (oldstate && oldstate->grid[y*w+x] != state->grid[y*w+x]) {
1162 * Compute the distance from this square to the
1163 * original player position.
1165 int dist = max(abs(x - oldstate->px), abs(y - oldstate->py));
1168 * If the player has reached here, use the new grid
1169 * element. Otherwise use the old one.
1171 if (player_dist < dist)
1172 v = oldstate->grid[y*w+x];
1174 v = state->grid[y*w+x];
1178 * Special case: erase the mine the dead player is
1179 * sitting on. Only at the end of the move.
1181 if (v == MINE && !oldstate && state->dead &&
1182 x == state->px && y == state->py)
1190 if (ds->grid[y*w+x] != v) {
1191 draw_tile(dr, ds, x, y, v);
1192 ds->grid[y*w+x] = v;
1197 * Gem counter in the status bar. We replace it with
1198 * `COMPLETED!' when it reaches zero ... or rather, when the
1199 * _current state_'s gem counter is zero. (Thus, `Gems: 0' is
1200 * shown between the collection of the last gem and the
1201 * completion of the move animation that did it.)
1203 if (state->dead && (!oldstate || oldstate->dead))
1204 sprintf(status, "DEAD!");
1205 else if (state->gems || (oldstate && oldstate->gems))
1206 sprintf(status, "Gems: %d", gems);
1208 sprintf(status, "COMPLETED!");
1209 /* We subtract one from the visible death counter if we're still
1210 * animating the move at the end of which the death took place. */
1211 deaths = ui->deaths;
1212 if (oldstate && ui->just_died) {
1217 sprintf(status + strlen(status), " Deaths: %d", deaths);
1218 status_bar(dr, status);
1221 * Draw the player sprite.
1223 assert(!ds->player_bg_saved);
1224 assert(ds->player_background);
1227 nx = COORD(state->px);
1228 ny = COORD(state->py);
1230 ox = COORD(oldstate->px);
1231 oy = COORD(oldstate->py);
1236 ds->pbgx = ox + ap * (nx - ox);
1237 ds->pbgy = oy + ap * (ny - oy);
1239 blitter_save(dr, ds->player_background, ds->pbgx, ds->pbgy);
1240 draw_player(dr, ds, ds->pbgx, ds->pbgy, (state->dead && !oldstate));
1241 ds->player_bg_saved = TRUE;
1244 static float game_anim_length(game_state *oldstate, game_state *newstate,
1245 int dir, game_ui *ui)
1249 dist = newstate->distance_moved;
1251 dist = oldstate->distance_moved;
1252 ui->anim_length = sqrt(dist) * BASE_ANIM_LENGTH;
1253 return ui->anim_length;
1256 static float game_flash_length(game_state *oldstate, game_state *newstate,
1257 int dir, game_ui *ui)
1259 if (!oldstate->dead && newstate->dead) {
1260 ui->flashtype = FLASH_DEAD;
1261 return FLASH_LENGTH;
1262 } else if (oldstate->gems && !newstate->gems) {
1263 ui->flashtype = FLASH_WIN;
1264 return FLASH_LENGTH;
1269 static int game_wants_statusbar(void)
1274 static int game_timing_state(game_state *state, game_ui *ui)
1279 static void game_print_size(game_params *params, float *x, float *y)
1283 static void game_print(drawing *dr, game_state *state, int tilesize)
1288 #define thegame inertia
1291 const struct game thegame = {
1292 "Inertia", "games.inertia",
1299 TRUE, game_configure, custom_params,
1307 FALSE, game_text_format,
1315 PREFERRED_TILESIZE, game_compute_size, game_set_size,
1318 game_free_drawstate,
1322 FALSE, FALSE, game_print_size, game_print,
1323 game_wants_statusbar,
1324 FALSE, game_timing_state,
1325 0, /* mouse_priorities */