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 (!reachable[i2]) {
375 #ifdef SOLVER_DIAGNOSTICS
376 printf(" trying point %d,%d,%d", x2, y2, d2);
379 ok = can_go(w, h, grid, x, y, dir, x2, y2, d2);
381 ok = can_go(w, h, grid, x2, y2, d2, x, y, dir);
382 #ifdef SOLVER_DIAGNOSTICS
383 printf(" - %sok\n", ok ? "" : "not ");
386 sc->positions[tail++] = i2;
387 reachable[i2] = TRUE;
395 * And that should be it. Now all we have to do is find the
396 * squares for which there exists _some_ direction such that
397 * the square plus that direction form a tuple which is both
398 * reachable from the start and reachable to the start.
401 for (gy = 0; gy < h; gy++)
402 for (gx = 0; gx < w; gx++)
403 if (AT(w, h, grid, gx, gy) == BLANK) {
404 for (gd = 0; gd < DIRECTIONS; gd++) {
405 int index = (gy*w+gx)*DIRECTIONS+gd;
406 if (sc->reachable_from[index] && sc->reachable_to[index]) {
407 #ifdef SOLVER_DIAGNOSTICS
408 printf("space at %d,%d is reachable via"
409 " direction %d\n", gx, gy, gd);
411 LV_AT(w, h, grid, gx, gy) = POSSGEM;
421 /* ----------------------------------------------------------------------
422 * Grid generation code.
425 static char *gengrid(int w, int h, random_state *rs)
428 char *grid = snewn(wh+1, char);
429 struct solver_scratch *sc = new_scratch(w, h);
430 int maxdist_threshold, tries;
432 maxdist_threshold = 2;
438 int *dist, *list, head, tail, maxdist;
441 * We're going to fill the grid with the five basic piece
442 * types in about 1/5 proportion. For the moment, though,
443 * we leave out the gems, because we'll put those in
444 * _after_ we run the solver to tell us where the viable
448 for (j = 0; j < wh/5; j++)
450 for (j = 0; j < wh/5; j++)
452 for (j = 0; j < wh/5; j++)
458 shuffle(grid, wh, sizeof(*grid), rs);
461 * Find the viable gem locations, and immediately give up
462 * and try again if there aren't enough of them.
464 possgems = find_gem_candidates(w, h, grid, sc);
469 * We _could_ now select wh/5 of the POSSGEMs and set them
470 * to GEM, and have a viable level. However, there's a
471 * chance that a large chunk of the level will turn out to
472 * be unreachable, so first we test for that.
474 * We do this by finding the largest distance from any
475 * square to the nearest POSSGEM, by breadth-first search.
476 * If this is above a critical threshold, we abort and try
479 * (This search is purely geometric, without regard to
480 * walls and long ways round.)
482 dist = sc->positions;
483 list = sc->positions + wh;
484 for (i = 0; i < wh; i++)
487 for (i = 0; i < wh; i++)
488 if (grid[i] == POSSGEM) {
493 while (head < tail) {
497 if (maxdist < dist[pos])
503 for (d = 0; d < DIRECTIONS; d++) {
509 if (x2 >= 0 && x2 < w && y2 >= 0 && y2 < h) {
512 dist[p2] = dist[pos] + 1;
518 assert(head == wh && tail == wh);
521 * Now abandon this grid and go round again if maxdist is
522 * above the required threshold.
524 * We can safely start the threshold as low as 2. As we
525 * accumulate failed generation attempts, we gradually
526 * raise it as we get more desperate.
528 if (maxdist > maxdist_threshold) {
538 * Now our reachable squares are plausibly evenly
539 * distributed over the grid. I'm not actually going to
540 * _enforce_ that I place the gems in such a way as not to
541 * increase that maxdist value; I'm now just going to trust
542 * to the RNG to pick a sensible subset of the POSSGEMs.
545 for (i = 0; i < wh; i++)
546 if (grid[i] == POSSGEM)
548 shuffle(list, j, sizeof(*list), rs);
549 for (i = 0; i < j; i++)
550 grid[list[i]] = (i < wh/5 ? GEM : BLANK);
561 static char *new_game_desc(game_params *params, random_state *rs,
562 char **aux, int interactive)
564 return gengrid(params->w, params->h, rs);
567 static char *validate_desc(game_params *params, char *desc)
569 int w = params->w, h = params->h, wh = w*h;
570 int starts = 0, gems = 0, i;
572 for (i = 0; i < wh; i++) {
574 return "Not enough data to fill grid";
575 if (desc[i] != WALL && desc[i] != START && desc[i] != STOP &&
576 desc[i] != GEM && desc[i] != MINE && desc[i] != BLANK)
577 return "Unrecognised character in game description";
578 if (desc[i] == START)
584 return "Too much data to fill grid";
586 return "No starting square specified";
588 return "More than one starting square specified";
590 return "No gems specified";
595 static game_state *new_game(midend *me, game_params *params, char *desc)
597 int w = params->w, h = params->h, wh = w*h;
599 game_state *state = snew(game_state);
601 state->p = *params; /* structure copy */
603 state->grid = snewn(wh, char);
604 assert(strlen(desc) == wh);
605 memcpy(state->grid, desc, wh);
607 state->px = state->py = -1;
609 for (i = 0; i < wh; i++) {
610 if (state->grid[i] == START) {
611 state->grid[i] = STOP;
614 } else if (state->grid[i] == GEM) {
619 assert(state->gems > 0);
620 assert(state->px >= 0 && state->py >= 0);
622 state->distance_moved = 0;
628 static game_state *dup_game(game_state *state)
630 int w = state->p.w, h = state->p.h, wh = w*h;
631 game_state *ret = snew(game_state);
636 ret->gems = state->gems;
637 ret->grid = snewn(wh, char);
638 ret->distance_moved = state->distance_moved;
640 memcpy(ret->grid, state->grid, wh);
645 static void free_game(game_state *state)
651 static char *solve_game(game_state *state, game_state *currstate,
652 char *aux, char **error)
657 static char *game_text_format(game_state *state)
670 static game_ui *new_ui(game_state *state)
672 game_ui *ui = snew(game_ui);
673 ui->anim_length = 0.0F;
676 ui->just_made_move = FALSE;
677 ui->just_died = FALSE;
681 static void free_ui(game_ui *ui)
686 static char *encode_ui(game_ui *ui)
690 * The deaths counter needs preserving across a serialisation.
692 sprintf(buf, "D%d", ui->deaths);
696 static void decode_ui(game_ui *ui, char *encoding)
699 sscanf(encoding, "D%d%n", &ui->deaths, &p);
702 static void game_changed_state(game_ui *ui, game_state *oldstate,
703 game_state *newstate)
706 * Increment the deaths counter. We only do this if
707 * ui->just_made_move is set (redoing a suicide move doesn't
708 * kill you _again_), and also we only do it if the game isn't
709 * completed (once you're finished, you can play).
711 if (!oldstate->dead && newstate->dead && ui->just_made_move &&
714 ui->just_died = TRUE;
716 ui->just_died = FALSE;
718 ui->just_made_move = FALSE;
721 struct game_drawstate {
725 unsigned short *grid;
726 blitter *player_background;
727 int player_bg_saved, pbgx, pbgy;
730 #define PREFERRED_TILESIZE 32
731 #define TILESIZE (ds->tilesize)
732 #define BORDER (TILESIZE)
733 #define HIGHLIGHT_WIDTH (TILESIZE / 10)
734 #define COORD(x) ( (x) * TILESIZE + BORDER )
735 #define FROMCOORD(x) ( ((x) - BORDER + TILESIZE) / TILESIZE - 1 )
737 static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds,
738 int x, int y, int button)
740 int w = state->p.w, h = state->p.h /*, wh = w*h */;
746 if (button == LEFT_BUTTON) {
748 * Mouse-clicking near the target point (or, more
749 * accurately, in the appropriate octant) is an alternative
750 * way to input moves.
753 if (FROMCOORD(x) != state->px || FROMCOORD(y) != state->py) {
757 dx = FROMCOORD(x) - state->px;
758 dy = FROMCOORD(y) - state->py;
759 /* I pass dx,dy rather than dy,dx so that the octants
760 * end up the right way round. */
761 angle = atan2(dx, -dy);
763 angle = (angle + (PI/8)) / (PI/4);
764 assert(angle > -16.0F);
765 dir = (int)(angle + 16.0F) & 7;
767 } else if (button == CURSOR_UP || button == (MOD_NUM_KEYPAD | '8'))
769 else if (button == CURSOR_DOWN || button == (MOD_NUM_KEYPAD | '2'))
771 else if (button == CURSOR_LEFT || button == (MOD_NUM_KEYPAD | '4'))
773 else if (button == CURSOR_RIGHT || button == (MOD_NUM_KEYPAD | '6'))
775 else if (button == (MOD_NUM_KEYPAD | '7'))
777 else if (button == (MOD_NUM_KEYPAD | '1'))
779 else if (button == (MOD_NUM_KEYPAD | '9'))
781 else if (button == (MOD_NUM_KEYPAD | '3'))
788 * Reject the move if we can't make it at all due to a wall
791 if (AT(w, h, state->grid, state->px+DX(dir), state->py+DY(dir)) == WALL)
795 * Reject the move if we're dead!
801 * Otherwise, we can make the move. All we need to specify is
804 ui->just_made_move = TRUE;
805 sprintf(buf, "%d", dir);
809 static game_state *execute_move(game_state *state, char *move)
811 int w = state->p.w, h = state->p.h /*, wh = w*h */;
812 int dir = atoi(move);
815 if (dir < 0 || dir >= DIRECTIONS)
816 return NULL; /* huh? */
821 if (AT(w, h, state->grid, state->px+DX(dir), state->py+DY(dir)) == WALL)
822 return NULL; /* wall in the way! */
827 ret = dup_game(state);
828 ret->distance_moved = 0;
832 ret->distance_moved++;
834 if (AT(w, h, ret->grid, ret->px, ret->py) == GEM) {
835 LV_AT(w, h, ret->grid, ret->px, ret->py) = BLANK;
839 if (AT(w, h, ret->grid, ret->px, ret->py) == MINE) {
844 if (AT(w, h, ret->grid, ret->px, ret->py) == STOP ||
845 AT(w, h, ret->grid, ret->px+DX(dir),
846 ret->py+DY(dir)) == WALL)
853 /* ----------------------------------------------------------------------
857 static void game_compute_size(game_params *params, int tilesize,
860 /* Ick: fake up `ds->tilesize' for macro expansion purposes */
861 struct { int tilesize; } ads, *ds = &ads;
862 ads.tilesize = tilesize;
864 *x = 2 * BORDER + 1 + params->w * TILESIZE;
865 *y = 2 * BORDER + 1 + params->h * TILESIZE;
868 static void game_set_size(drawing *dr, game_drawstate *ds,
869 game_params *params, int tilesize)
871 ds->tilesize = tilesize;
873 assert(!ds->player_bg_saved);
875 if (ds->player_background)
876 blitter_free(dr, ds->player_background);
877 ds->player_background = blitter_new(dr, TILESIZE, TILESIZE);
880 static float *game_colours(frontend *fe, game_state *state, int *ncolours)
882 float *ret = snewn(3 * NCOLOURS, float);
885 game_mkhighlight(fe, ret, COL_BACKGROUND, COL_HIGHLIGHT, COL_LOWLIGHT);
887 ret[COL_OUTLINE * 3 + 0] = 0.0F;
888 ret[COL_OUTLINE * 3 + 1] = 0.0F;
889 ret[COL_OUTLINE * 3 + 2] = 0.0F;
891 ret[COL_PLAYER * 3 + 0] = 0.0F;
892 ret[COL_PLAYER * 3 + 1] = 1.0F;
893 ret[COL_PLAYER * 3 + 2] = 0.0F;
895 ret[COL_DEAD_PLAYER * 3 + 0] = 1.0F;
896 ret[COL_DEAD_PLAYER * 3 + 1] = 0.0F;
897 ret[COL_DEAD_PLAYER * 3 + 2] = 0.0F;
899 ret[COL_MINE * 3 + 0] = 0.0F;
900 ret[COL_MINE * 3 + 1] = 0.0F;
901 ret[COL_MINE * 3 + 2] = 0.0F;
903 ret[COL_GEM * 3 + 0] = 0.6F;
904 ret[COL_GEM * 3 + 1] = 1.0F;
905 ret[COL_GEM * 3 + 2] = 1.0F;
907 for (i = 0; i < 3; i++) {
908 ret[COL_WALL * 3 + i] = (3 * ret[COL_BACKGROUND * 3 + i] +
909 1 * ret[COL_HIGHLIGHT * 3 + i]) / 4;
912 *ncolours = NCOLOURS;
916 static game_drawstate *game_new_drawstate(drawing *dr, game_state *state)
918 int w = state->p.w, h = state->p.h, wh = w*h;
919 struct game_drawstate *ds = snew(struct game_drawstate);
924 /* We can't allocate the blitter rectangle for the player background
925 * until we know what size to make it. */
926 ds->player_background = NULL;
927 ds->player_bg_saved = FALSE;
928 ds->pbgx = ds->pbgy = -1;
930 ds->p = state->p; /* structure copy */
932 ds->grid = snewn(wh, unsigned short);
933 for (i = 0; i < wh; i++)
934 ds->grid[i] = UNDRAWN;
939 static void game_free_drawstate(drawing *dr, game_drawstate *ds)
945 static void draw_player(drawing *dr, game_drawstate *ds, int x, int y,
949 int coords[DIRECTIONS*4];
952 for (d = 0; d < DIRECTIONS; d++) {
953 float x1, y1, x2, y2, x3, y3, len;
957 len = sqrt(x1*x1+y1*y1); x1 /= len; y1 /= len;
961 len = sqrt(x3*x3+y3*y3); x3 /= len; y3 /= len;
966 coords[d*4+0] = x + TILESIZE/2 + (int)((TILESIZE*3/7) * x1);
967 coords[d*4+1] = y + TILESIZE/2 + (int)((TILESIZE*3/7) * y1);
968 coords[d*4+2] = x + TILESIZE/2 + (int)((TILESIZE*3/7) * x2);
969 coords[d*4+3] = y + TILESIZE/2 + (int)((TILESIZE*3/7) * y2);
971 draw_polygon(dr, coords, DIRECTIONS*2, COL_DEAD_PLAYER, COL_OUTLINE);
973 draw_circle(dr, x + TILESIZE/2, y + TILESIZE/2,
974 TILESIZE/3, COL_PLAYER, COL_OUTLINE);
976 draw_update(dr, x, y, TILESIZE, TILESIZE);
979 #define FLASH_DEAD 0x100
980 #define FLASH_WIN 0x200
981 #define FLASH_MASK 0x300
983 static void draw_tile(drawing *dr, game_drawstate *ds, int x, int y, int v)
985 int tx = COORD(x), ty = COORD(y);
986 int bg = (v & FLASH_DEAD ? COL_DEAD_PLAYER :
987 v & FLASH_WIN ? COL_HIGHLIGHT : COL_BACKGROUND);
991 clip(dr, tx+1, ty+1, TILESIZE-1, TILESIZE-1);
992 draw_rect(dr, tx+1, ty+1, TILESIZE-1, TILESIZE-1, bg);
997 coords[0] = tx + TILESIZE;
998 coords[1] = ty + TILESIZE;
999 coords[2] = tx + TILESIZE;
1002 coords[5] = ty + TILESIZE;
1003 draw_polygon(dr, coords, 3, COL_LOWLIGHT, COL_LOWLIGHT);
1007 draw_polygon(dr, coords, 3, COL_HIGHLIGHT, COL_HIGHLIGHT);
1009 draw_rect(dr, tx + 1 + HIGHLIGHT_WIDTH, ty + 1 + HIGHLIGHT_WIDTH,
1010 TILESIZE - 2*HIGHLIGHT_WIDTH,
1011 TILESIZE - 2*HIGHLIGHT_WIDTH, COL_WALL);
1012 } else if (v == MINE) {
1013 int cx = tx + TILESIZE / 2;
1014 int cy = ty + TILESIZE / 2;
1015 int r = TILESIZE / 2 - 3;
1017 int xdx = 1, xdy = 0, ydx = 0, ydy = 1;
1020 for (i = 0; i < 4*5*2; i += 5*2) {
1021 coords[i+2*0+0] = cx - r/6*xdx + r*4/5*ydx;
1022 coords[i+2*0+1] = cy - r/6*xdy + r*4/5*ydy;
1023 coords[i+2*1+0] = cx - r/6*xdx + r*ydx;
1024 coords[i+2*1+1] = cy - r/6*xdy + r*ydy;
1025 coords[i+2*2+0] = cx + r/6*xdx + r*ydx;
1026 coords[i+2*2+1] = cy + r/6*xdy + r*ydy;
1027 coords[i+2*3+0] = cx + r/6*xdx + r*4/5*ydx;
1028 coords[i+2*3+1] = cy + r/6*xdy + r*4/5*ydy;
1029 coords[i+2*4+0] = cx + r*3/5*xdx + r*3/5*ydx;
1030 coords[i+2*4+1] = cy + r*3/5*xdy + r*3/5*ydy;
1040 draw_polygon(dr, coords, 5*4, COL_MINE, COL_MINE);
1042 draw_rect(dr, cx-r/3, cy-r/3, r/3, r/4, COL_HIGHLIGHT);
1043 } else if (v == STOP) {
1044 draw_circle(dr, tx + TILESIZE/2, ty + TILESIZE/2,
1045 TILESIZE*3/7, -1, COL_OUTLINE);
1046 draw_rect(dr, tx + TILESIZE*3/7, ty+1,
1047 TILESIZE - 2*(TILESIZE*3/7) + 1, TILESIZE-1, bg);
1048 draw_rect(dr, tx+1, ty + TILESIZE*3/7,
1049 TILESIZE-1, TILESIZE - 2*(TILESIZE*3/7) + 1, bg);
1050 } else if (v == GEM) {
1053 coords[0] = tx+TILESIZE/2;
1054 coords[1] = ty+TILESIZE*1/7;
1055 coords[2] = tx+TILESIZE*1/7;
1056 coords[3] = ty+TILESIZE/2;
1057 coords[4] = tx+TILESIZE/2;
1058 coords[5] = ty+TILESIZE-TILESIZE*1/7;
1059 coords[6] = tx+TILESIZE-TILESIZE*1/7;
1060 coords[7] = ty+TILESIZE/2;
1062 draw_polygon(dr, coords, 4, COL_GEM, COL_OUTLINE);
1066 draw_update(dr, tx, ty, TILESIZE, TILESIZE);
1069 #define BASE_ANIM_LENGTH 0.1F
1070 #define FLASH_LENGTH 0.3F
1072 static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate,
1073 game_state *state, int dir, game_ui *ui,
1074 float animtime, float flashtime)
1076 int w = state->p.w, h = state->p.h /*, wh = w*h */;
1085 !((int)(flashtime * 3 / FLASH_LENGTH) % 2))
1086 flashtype = ui->flashtype;
1091 * Erase the player sprite.
1093 if (ds->player_bg_saved) {
1094 assert(ds->player_background);
1095 blitter_load(dr, ds->player_background, ds->pbgx, ds->pbgy);
1096 draw_update(dr, ds->pbgx, ds->pbgy, TILESIZE, TILESIZE);
1097 ds->player_bg_saved = FALSE;
1101 * Initialise a fresh drawstate.
1107 * Blank out the window initially.
1109 game_compute_size(&ds->p, TILESIZE, &wid, &ht);
1110 draw_rect(dr, 0, 0, wid, ht, COL_BACKGROUND);
1111 draw_update(dr, 0, 0, wid, ht);
1114 * Draw the grid lines.
1116 for (y = 0; y <= h; y++)
1117 draw_line(dr, COORD(0), COORD(y), COORD(w), COORD(y),
1119 for (x = 0; x <= w; x++)
1120 draw_line(dr, COORD(x), COORD(0), COORD(x), COORD(h),
1127 * If we're in the process of animating a move, let's start by
1128 * working out how far the player has moved from their _older_
1132 ap = animtime / ui->anim_length;
1133 player_dist = ap * (dir > 0 ? state : oldstate)->distance_moved;
1140 * Draw the grid contents.
1142 * We count the gems as we go round this loop, for the purposes
1143 * of the status bar. Of course we have a gems counter in the
1144 * game_state already, but if we do the counting in this loop
1145 * then it tracks gems being picked up in a sliding move, and
1146 * updates one by one.
1149 for (y = 0; y < h; y++)
1150 for (x = 0; x < w; x++) {
1151 unsigned short v = (unsigned char)state->grid[y*w+x];
1154 * Special case: if the player is in the process of
1155 * moving over a gem, we draw the gem iff they haven't
1158 if (oldstate && oldstate->grid[y*w+x] != state->grid[y*w+x]) {
1160 * Compute the distance from this square to the
1161 * original player position.
1163 int dist = max(abs(x - oldstate->px), abs(y - oldstate->py));
1166 * If the player has reached here, use the new grid
1167 * element. Otherwise use the old one.
1169 if (player_dist < dist)
1170 v = oldstate->grid[y*w+x];
1172 v = state->grid[y*w+x];
1176 * Special case: erase the mine the dead player is
1177 * sitting on. Only at the end of the move.
1179 if (v == MINE && !oldstate && state->dead &&
1180 x == state->px && y == state->py)
1188 if (ds->grid[y*w+x] != v) {
1189 draw_tile(dr, ds, x, y, v);
1190 ds->grid[y*w+x] = v;
1195 * Gem counter in the status bar. We replace it with
1196 * `COMPLETED!' when it reaches zero ... or rather, when the
1197 * _current state_'s gem counter is zero. (Thus, `Gems: 0' is
1198 * shown between the collection of the last gem and the
1199 * completion of the move animation that did it.)
1201 if (state->dead && (!oldstate || oldstate->dead))
1202 sprintf(status, "DEAD!");
1203 else if (state->gems || (oldstate && oldstate->gems))
1204 sprintf(status, "Gems: %d", gems);
1206 sprintf(status, "COMPLETED!");
1207 /* We subtract one from the visible death counter if we're still
1208 * animating the move at the end of which the death took place. */
1209 deaths = ui->deaths;
1210 if (oldstate && ui->just_died) {
1215 sprintf(status + strlen(status), " Deaths: %d", deaths);
1216 status_bar(dr, status);
1219 * Draw the player sprite.
1221 assert(!ds->player_bg_saved);
1222 assert(ds->player_background);
1225 nx = COORD(state->px);
1226 ny = COORD(state->py);
1228 ox = COORD(oldstate->px);
1229 oy = COORD(oldstate->py);
1234 ds->pbgx = ox + ap * (nx - ox);
1235 ds->pbgy = oy + ap * (ny - oy);
1237 blitter_save(dr, ds->player_background, ds->pbgx, ds->pbgy);
1238 draw_player(dr, ds, ds->pbgx, ds->pbgy, (state->dead && !oldstate));
1239 ds->player_bg_saved = TRUE;
1242 static float game_anim_length(game_state *oldstate, game_state *newstate,
1243 int dir, game_ui *ui)
1247 dist = newstate->distance_moved;
1249 dist = oldstate->distance_moved;
1250 ui->anim_length = sqrt(dist) * BASE_ANIM_LENGTH;
1251 return ui->anim_length;
1254 static float game_flash_length(game_state *oldstate, game_state *newstate,
1255 int dir, game_ui *ui)
1257 if (!oldstate->dead && newstate->dead) {
1258 ui->flashtype = FLASH_DEAD;
1259 return FLASH_LENGTH;
1260 } else if (oldstate->gems && !newstate->gems) {
1261 ui->flashtype = FLASH_WIN;
1262 return FLASH_LENGTH;
1267 static int game_wants_statusbar(void)
1272 static int game_timing_state(game_state *state, game_ui *ui)
1277 static void game_print_size(game_params *params, float *x, float *y)
1281 static void game_print(drawing *dr, game_state *state, int tilesize)
1286 #define thegame inertia
1289 const struct game thegame = {
1290 "Inertia", "games.inertia",
1297 TRUE, game_configure, custom_params,
1305 FALSE, game_text_format,
1313 PREFERRED_TILESIZE, game_compute_size, game_set_size,
1316 game_free_drawstate,
1320 FALSE, FALSE, game_print_size, game_print,
1321 game_wants_statusbar,
1322 FALSE, game_timing_state,
1323 0, /* mouse_priorities */