2 * twiddle.c: Puzzle involving rearranging a grid of squares by
3 * rotating subsquares. Adapted and generalised from a
4 * door-unlocking puzzle in Metroid Prime 2 (the one in the Main
18 #define BORDER (TILE_SIZE / 2)
19 #define HIGHLIGHT_WIDTH (TILE_SIZE / 20)
20 #define COORD(x) ( (x) * TILE_SIZE + BORDER )
21 #define FROMCOORD(x) ( ((x) - BORDER + TILE_SIZE) / TILE_SIZE - 1 )
23 #define PI 3.141592653589793238462643383279502884197169399
25 #define ANIM_PER_RADIUS_UNIT 0.13F
26 #define FLASH_FRAME 0.13F
50 int lastx, lasty, lastr; /* coordinates of last rotation */
53 static game_params *default_params(void)
55 game_params *ret = snew(game_params);
59 ret->rowsonly = ret->orientable = FALSE;
65 static void free_params(game_params *params)
70 static game_params *dup_params(game_params *params)
72 game_params *ret = snew(game_params);
73 *ret = *params; /* structure copy */
77 static int game_fetch_preset(int i, char **name, game_params **params)
83 { "3x3 rows only", { 3, 3, 2, TRUE, FALSE } },
84 { "3x3 normal", { 3, 3, 2, FALSE, FALSE } },
85 { "3x3 orientable", { 3, 3, 2, FALSE, TRUE } },
86 { "4x4 normal", { 4, 4, 2, FALSE } },
87 { "4x4 orientable", { 4, 4, 2, FALSE, TRUE } },
88 { "4x4 radius 3", { 4, 4, 3, FALSE } },
89 { "5x5 radius 3", { 5, 5, 3, FALSE } },
90 { "6x6 radius 4", { 6, 6, 4, FALSE } },
93 if (i < 0 || i >= lenof(presets))
96 *name = dupstr(presets[i].title);
97 *params = dup_params(&presets[i].params);
102 static game_params *decode_params(char const *string)
104 game_params *ret = snew(game_params);
106 ret->w = ret->h = atoi(string);
108 ret->rowsonly = ret->orientable = FALSE;
109 while (*string && isdigit(*string)) string++;
110 if (*string == 'x') {
112 ret->h = atoi(string);
113 while (*string && isdigit(*string)) string++;
115 if (*string == 'n') {
117 ret->n = atoi(string);
118 while (*string && isdigit(*string)) string++;
121 if (*string == 'r') {
122 ret->rowsonly = TRUE;
123 } else if (*string == 'o') {
124 ret->orientable = TRUE;
132 static char *encode_params(game_params *params)
135 sprintf(buf, "%dx%dn%d%s%s", params->w, params->h, params->n,
136 params->rowsonly ? "r" : "",
137 params->orientable ? "o" : "");
141 static config_item *game_configure(game_params *params)
146 ret = snewn(6, 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);
160 ret[2].name = "Rotation radius";
161 ret[2].type = C_STRING;
162 sprintf(buf, "%d", params->n);
163 ret[2].sval = dupstr(buf);
166 ret[3].name = "One number per row";
167 ret[3].type = C_BOOLEAN;
169 ret[3].ival = params->rowsonly;
171 ret[4].name = "Orientation matters";
172 ret[4].type = C_BOOLEAN;
174 ret[4].ival = params->orientable;
184 static game_params *custom_params(config_item *cfg)
186 game_params *ret = snew(game_params);
188 ret->w = atoi(cfg[0].sval);
189 ret->h = atoi(cfg[1].sval);
190 ret->n = atoi(cfg[2].sval);
191 ret->rowsonly = cfg[3].ival;
192 ret->orientable = cfg[4].ival;
197 static char *validate_params(game_params *params)
200 return "Rotation radius must be at least two";
201 if (params->w < params->n)
202 return "Width must be at least the rotation radius";
203 if (params->h < params->n)
204 return "Height must be at least the rotation radius";
209 * This function actually performs a rotation on a grid. The `x'
210 * and `y' coordinates passed in are the coordinates of the _top
211 * left corner_ of the rotated region. (Using the centre would have
212 * involved half-integers and been annoyingly fiddly. Clicking in
213 * the centre is good for a user interface, but too inconvenient to
216 static void do_rotate(int *grid, int w, int h, int n, int orientable,
217 int x, int y, int dir)
221 assert(x >= 0 && x+n <= w);
222 assert(y >= 0 && y+n <= h);
225 return; /* nothing to do */
227 grid += y*w+x; /* translate region to top corner */
230 * If we were leaving the result of the rotation in a separate
231 * grid, the simple thing to do would be to loop over each
232 * square within the rotated region and assign it from its
233 * source square. However, to do it in place without taking
234 * O(n^2) memory, we need to be marginally more clever. What
235 * I'm going to do is loop over about one _quarter_ of the
236 * rotated region and permute each element within that quarter
237 * with its rotational coset.
239 * The size of the region I need to loop over is (n+1)/2 by
240 * n/2, which is an obvious exact quarter for even n and is a
241 * rectangle for odd n. (For odd n, this technique leaves out
242 * one element of the square, which is of course the central
243 * one that never moves anyway.)
245 for (i = 0; i < (n+1)/2; i++) {
246 for (j = 0; j < n/2; j++) {
256 for (k = 0; k < 4; k++)
259 for (k = 0; k < 4; k++) {
260 int v = g[(k+dir) & 3];
262 v ^= ((v+dir) ^ v) & 3; /* alter orientation */
269 * Don't forget the orientation on the centre square, if n is
272 if (orientable && (n & 1)) {
273 int v = grid[n/2*(w+1)];
274 v ^= ((v+dir) ^ v) & 3; /* alter orientation */
279 static int grid_complete(int *grid, int wh, int orientable)
283 for (i = 1; i < wh; i++)
284 if (grid[i] < grid[i-1])
287 for (i = 0; i < wh; i++)
294 static char *new_game_seed(game_params *params, random_state *rs,
298 int w = params->w, h = params->h, n = params->n, wh = w*h;
305 * Set up a solved grid.
307 grid = snewn(wh, int);
308 for (i = 0; i < wh; i++)
309 grid[i] = ((params->rowsonly ? i/w : i) + 1) * 4;
312 * Shuffle it. This game is complex enough that I don't feel up
313 * to analysing its full symmetry properties (particularly at
314 * n=4 and above!), so I'm going to do it the pedestrian way
315 * and simply shuffle the grid by making a long sequence of
316 * randomly chosen moves.
318 total_moves = w*h*n*n*2;
319 for (i = 0; i < total_moves; i++) {
322 x = random_upto(rs, w - n + 1);
323 y = random_upto(rs, h - n + 1);
324 do_rotate(grid, w, h, n, params->orientable,
325 x, y, 1 + random_upto(rs, 3));
328 * Optionally one more move in case the entire grid has
329 * happened to come out solved.
331 if (i == total_moves - 1 && grid_complete(grid, wh,
337 * Now construct the game seed, by describing the grid as a
338 * simple sequence of integers. They're comma-separated, unless
339 * the puzzle is orientable in which case they're separated by
340 * orientation letters `u', `d', `l' and `r'.
344 for (i = 0; i < wh; i++) {
348 k = sprintf(buf, "%d%c", grid[i] / 4,
349 params->orientable ? "uldr"[grid[i] & 3] : ',');
351 ret = sresize(ret, retlen + k + 1, char);
352 strcpy(ret + retlen, buf);
355 if (!params->orientable)
356 ret[retlen-1] = '\0'; /* delete last comma */
362 void game_free_aux_info(game_aux_info *aux)
364 assert(!"Shouldn't happen");
367 static char *validate_seed(game_params *params, char *seed)
370 int w = params->w, h = params->h, wh = w*h;
376 for (i = 0; i < wh; i++) {
377 if (*p < '0' || *p > '9')
378 return "Not enough numbers in string";
379 while (*p >= '0' && *p <= '9')
381 if (!params->orientable && i < wh-1) {
383 return "Expected comma after number";
384 } else if (params->orientable && i < wh) {
385 if (*p != 'l' && *p != 'r' && *p != 'u' && *p != 'd')
386 return "Expected orientation letter after number";
387 } else if (i == wh-1 && *p) {
388 return "Excess junk at end of string";
391 if (*p) p++; /* eat comma */
397 static game_state *new_game(game_params *params, char *seed)
399 game_state *state = snew(game_state);
400 int w = params->w, h = params->h, n = params->n, wh = w*h;
407 state->orientable = params->orientable;
408 state->completed = 0;
409 state->movecount = 0;
410 state->lastx = state->lasty = state->lastr = -1;
412 state->grid = snewn(wh, int);
416 for (i = 0; i < wh; i++) {
417 state->grid[i] = 4 * atoi(p);
418 while (*p >= '0' && *p <= '9')
421 if (params->orientable) {
423 case 'l': state->grid[i] |= 1; break;
424 case 'd': state->grid[i] |= 2; break;
425 case 'r': state->grid[i] |= 3; break;
435 static game_state *dup_game(game_state *state)
437 game_state *ret = snew(game_state);
442 ret->orientable = state->orientable;
443 ret->completed = state->completed;
444 ret->movecount = state->movecount;
445 ret->lastx = state->lastx;
446 ret->lasty = state->lasty;
447 ret->lastr = state->lastr;
449 ret->grid = snewn(ret->w * ret->h, int);
450 memcpy(ret->grid, state->grid, ret->w * ret->h * sizeof(int));
455 static void free_game(game_state *state)
461 static char *game_text_format(game_state *state)
463 char *ret, *p, buf[80];
464 int i, x, y, col, o, maxlen;
467 * First work out how many characters we need to display each
468 * number. We're pretty flexible on grid contents here, so we
469 * have to scan the entire grid.
472 for (i = 0; i < state->w * state->h; i++) {
473 x = sprintf(buf, "%d", state->grid[i] / 4);
474 if (col < x) col = x;
476 o = (state->orientable ? 1 : 0);
479 * Now we know the exact total size of the grid we're going to
480 * produce: it's got h rows, each containing w lots of col+o,
481 * w-1 spaces and a trailing newline.
483 maxlen = state->h * state->w * (col+o+1);
485 ret = snewn(maxlen, char);
488 for (y = 0; y < state->h; y++) {
489 for (x = 0; x < state->w; x++) {
490 int v = state->grid[state->w*y+x];
491 sprintf(buf, "%*d", col, v/4);
495 *p++ = "^<v>"[v & 3];
503 assert(p - ret == maxlen);
508 static game_ui *new_ui(game_state *state)
513 static void free_ui(game_ui *ui)
517 static game_state *make_move(game_state *from, game_ui *ui, int x, int y,
520 int w = from->w, h = from->h, n = from->n, wh = w*h;
524 if (button == LEFT_BUTTON || button == RIGHT_BUTTON) {
526 * Determine the coordinates of the click. We offset by n-1
527 * half-blocks so that the user must click at the centre of
528 * a rotation region rather than at the corner.
530 x -= (n-1) * TILE_SIZE / 2;
531 y -= (n-1) * TILE_SIZE / 2;
534 if (x < 0 || x > w-n || y < 0 || y > w-n)
538 * This is a valid move. Make it.
540 ret = dup_game(from);
542 dir = (button == LEFT_BUTTON ? 1 : -1);
543 do_rotate(ret->grid, w, h, n, ret->orientable, x, y, dir);
549 * See if the game has been completed. To do this we simply
550 * test that the grid contents are in increasing order.
552 if (!ret->completed && grid_complete(ret->grid, wh, ret->orientable))
553 ret->completed = ret->movecount;
559 /* ----------------------------------------------------------------------
563 struct game_drawstate {
569 static void game_size(game_params *params, int *x, int *y)
571 *x = TILE_SIZE * params->w + 2 * BORDER;
572 *y = TILE_SIZE * params->h + 2 * BORDER;
575 static float *game_colours(frontend *fe, game_state *state, int *ncolours)
577 float *ret = snewn(3 * NCOLOURS, float);
581 frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
584 * Drop the background colour so that the highlight is
585 * noticeably brighter than it while still being under 1.
587 max = ret[COL_BACKGROUND*3];
588 for (i = 1; i < 3; i++)
589 if (ret[COL_BACKGROUND*3+i] > max)
590 max = ret[COL_BACKGROUND*3+i];
591 if (max * 1.2F > 1.0F) {
592 for (i = 0; i < 3; i++)
593 ret[COL_BACKGROUND*3+i] /= (max * 1.2F);
596 for (i = 0; i < 3; i++) {
597 ret[COL_HIGHLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 1.2F;
598 ret[COL_HIGHLIGHT_GENTLE * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 1.1F;
599 ret[COL_LOWLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 0.8F;
600 ret[COL_LOWLIGHT_GENTLE * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 0.9F;
601 ret[COL_TEXT * 3 + i] = 0.0;
604 *ncolours = NCOLOURS;
608 static game_drawstate *game_new_drawstate(game_state *state)
610 struct game_drawstate *ds = snew(struct game_drawstate);
616 ds->bgcolour = COL_BACKGROUND;
617 ds->grid = snewn(ds->w*ds->h, int);
618 for (i = 0; i < ds->w*ds->h; i++)
624 static void game_free_drawstate(game_drawstate *ds)
630 int cx, cy, cw, ch; /* clip region */
631 int ox, oy; /* rotation origin */
632 float c, s; /* cos and sin of rotation angle */
633 int lc, rc, tc, bc; /* colours of tile edges */
636 static void rotate(int *xy, struct rotation *rot)
639 float xf = xy[0] - rot->ox, yf = xy[1] - rot->oy;
642 xf2 = rot->c * xf + rot->s * yf;
643 yf2 = - rot->s * xf + rot->c * yf;
645 xy[0] = xf2 + rot->ox + 0.5; /* round to nearest */
646 xy[1] = yf2 + rot->oy + 0.5; /* round to nearest */
650 static void draw_tile(frontend *fe, game_state *state, int x, int y,
651 int tile, int flash_colour, struct rotation *rot)
657 clip(fe, rot->cx, rot->cy, rot->cw, rot->ch);
660 * We must draw each side of the tile's highlight separately,
661 * because in some cases (during rotation) they will all need
662 * to be different colours.
665 /* The centre point is common to all sides. */
666 coords[4] = x + TILE_SIZE / 2;
667 coords[5] = y + TILE_SIZE / 2;
668 rotate(coords+4, rot);
671 coords[0] = x + TILE_SIZE - 1;
672 coords[1] = y + TILE_SIZE - 1;
673 rotate(coords+0, rot);
674 coords[2] = x + TILE_SIZE - 1;
676 rotate(coords+2, rot);
677 draw_polygon(fe, coords, 3, TRUE, rot ? rot->rc : COL_LOWLIGHT);
678 draw_polygon(fe, coords, 3, FALSE, rot ? rot->rc : COL_LOWLIGHT);
682 coords[3] = y + TILE_SIZE - 1;
683 rotate(coords+2, rot);
684 draw_polygon(fe, coords, 3, TRUE, rot ? rot->bc : COL_LOWLIGHT);
685 draw_polygon(fe, coords, 3, FALSE, rot ? rot->bc : COL_LOWLIGHT);
690 rotate(coords+0, rot);
691 draw_polygon(fe, coords, 3, TRUE, rot ? rot->lc : COL_HIGHLIGHT);
692 draw_polygon(fe, coords, 3, FALSE, rot ? rot->lc : COL_HIGHLIGHT);
695 coords[2] = x + TILE_SIZE - 1;
697 rotate(coords+2, rot);
698 draw_polygon(fe, coords, 3, TRUE, rot ? rot->tc : COL_HIGHLIGHT);
699 draw_polygon(fe, coords, 3, FALSE, rot ? rot->tc : COL_HIGHLIGHT);
702 * Now the main blank area in the centre of the tile.
705 coords[0] = x + HIGHLIGHT_WIDTH;
706 coords[1] = y + HIGHLIGHT_WIDTH;
707 rotate(coords+0, rot);
708 coords[2] = x + HIGHLIGHT_WIDTH;
709 coords[3] = y + TILE_SIZE - 1 - HIGHLIGHT_WIDTH;
710 rotate(coords+2, rot);
711 coords[4] = x + TILE_SIZE - 1 - HIGHLIGHT_WIDTH;
712 coords[5] = y + TILE_SIZE - 1 - HIGHLIGHT_WIDTH;
713 rotate(coords+4, rot);
714 coords[6] = x + TILE_SIZE - 1 - HIGHLIGHT_WIDTH;
715 coords[7] = y + HIGHLIGHT_WIDTH;
716 rotate(coords+6, rot);
717 draw_polygon(fe, coords, 4, TRUE, flash_colour);
718 draw_polygon(fe, coords, 4, FALSE, flash_colour);
720 draw_rect(fe, x + HIGHLIGHT_WIDTH, y + HIGHLIGHT_WIDTH,
721 TILE_SIZE - 2*HIGHLIGHT_WIDTH, TILE_SIZE - 2*HIGHLIGHT_WIDTH,
726 * Next, the colour bars for orientation.
728 if (state->orientable) {
729 int xdx, xdy, ydx, ydy;
730 int cx, cy, displ, displ2;
744 default /* case 3 */:
750 cx = x + TILE_SIZE / 2;
751 cy = y + TILE_SIZE / 2;
752 displ = TILE_SIZE / 2 - HIGHLIGHT_WIDTH - 2;
753 displ2 = TILE_SIZE / 3 - HIGHLIGHT_WIDTH;
755 coords[0] = cx - displ * xdx + displ2 * ydx;
756 coords[1] = cy - displ * xdy + displ2 * ydy;
757 rotate(coords+0, rot);
758 coords[2] = cx + displ * xdx + displ2 * ydx;
759 coords[3] = cy + displ * xdy + displ2 * ydy;
760 rotate(coords+2, rot);
761 coords[4] = cx - displ * ydx;
762 coords[5] = cy - displ * ydy;
763 rotate(coords+4, rot);
764 draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT_GENTLE);
765 draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT_GENTLE);
768 coords[0] = x + TILE_SIZE/2;
769 coords[1] = y + TILE_SIZE/2;
770 rotate(coords+0, rot);
771 sprintf(str, "%d", tile / 4);
772 draw_text(fe, coords[0], coords[1],
773 FONT_VARIABLE, TILE_SIZE/3, ALIGN_VCENTRE | ALIGN_HCENTRE,
779 draw_update(fe, x, y, TILE_SIZE, TILE_SIZE);
782 static int highlight_colour(float angle)
789 COL_HIGHLIGHT_GENTLE,
790 COL_HIGHLIGHT_GENTLE,
791 COL_HIGHLIGHT_GENTLE,
802 COL_HIGHLIGHT_GENTLE,
803 COL_HIGHLIGHT_GENTLE,
804 COL_HIGHLIGHT_GENTLE,
819 return colours[(int)((angle + 2*PI) / (PI/16)) & 31];
822 static float game_anim_length(game_state *oldstate, game_state *newstate,
825 return ANIM_PER_RADIUS_UNIT * sqrt(newstate->n-1);
828 static float game_flash_length(game_state *oldstate, game_state *newstate,
831 if (!oldstate->completed && newstate->completed)
832 return 2 * FLASH_FRAME;
837 static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate,
838 game_state *state, int dir, game_ui *ui,
839 float animtime, float flashtime)
842 struct rotation srot, *rot;
843 int lastx = -1, lasty = -1, lastr = -1;
846 int frame = (int)(flashtime / FLASH_FRAME);
847 bgcolour = (frame % 2 ? COL_LOWLIGHT : COL_HIGHLIGHT);
849 bgcolour = COL_BACKGROUND;
855 TILE_SIZE * state->w + 2 * BORDER,
856 TILE_SIZE * state->h + 2 * BORDER, COL_BACKGROUND);
857 draw_update(fe, 0, 0,
858 TILE_SIZE * state->w + 2 * BORDER,
859 TILE_SIZE * state->h + 2 * BORDER);
862 * Recessed area containing the whole puzzle.
864 coords[0] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
865 coords[1] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
866 coords[2] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
867 coords[3] = COORD(0) - HIGHLIGHT_WIDTH;
868 coords[4] = COORD(0) - HIGHLIGHT_WIDTH;
869 coords[5] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
870 draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
871 draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);
873 coords[1] = COORD(0) - HIGHLIGHT_WIDTH;
874 coords[0] = COORD(0) - HIGHLIGHT_WIDTH;
875 draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
876 draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);
882 * If we're drawing any rotated tiles, sort out the rotation
883 * parameters, and also zap the rotation region to the
884 * background colour before doing anything else.
888 float anim_max = game_anim_length(oldstate, state, dir);
891 lastx = state->lastx;
892 lasty = state->lasty;
893 lastr = state->lastr;
895 lastx = oldstate->lastx;
896 lasty = oldstate->lasty;
897 lastr = -oldstate->lastr;
901 rot->cx = COORD(lastx);
902 rot->cy = COORD(lasty);
903 rot->cw = rot->ch = TILE_SIZE * state->n;
904 rot->ox = rot->cx + rot->cw/2;
905 rot->oy = rot->cy + rot->ch/2;
906 angle = (-PI/2 * lastr) * (1.0 - animtime / anim_max);
911 * Sort out the colours of the various sides of the tile.
913 rot->lc = highlight_colour(PI + angle);
914 rot->rc = highlight_colour(angle);
915 rot->tc = highlight_colour(PI/2 + angle);
916 rot->bc = highlight_colour(-PI/2 + angle);
918 draw_rect(fe, rot->cx, rot->cy, rot->cw, rot->ch, bgcolour);
923 * Now draw each tile.
925 for (i = 0; i < state->w * state->h; i++) {
927 int tx = i % state->w, ty = i / state->w;
930 * Figure out what should be displayed at this location.
931 * Usually it will be state->grid[i], unless we're in the
932 * middle of animating an actual rotation and this cell is
933 * within the rotation region, in which case we set -1
936 if (oldstate && lastx >= 0 && lasty >= 0 &&
937 tx >= lastx && tx < lastx + state->n &&
938 ty >= lasty && ty < lasty + state->n)
943 if (ds->bgcolour != bgcolour || /* always redraw when flashing */
944 ds->grid[i] != t || ds->grid[i] == -1 || t == -1) {
945 int x = COORD(tx), y = COORD(ty);
947 draw_tile(fe, state, x, y, state->grid[i], bgcolour, rot);
951 ds->bgcolour = bgcolour;
954 * Update the status bar.
960 * Don't show the new status until we're also showing the
961 * new _state_ - after the game animation is complete.
966 sprintf(statusbuf, "%sMoves: %d",
967 (state->completed ? "COMPLETED! " : ""),
968 (state->completed ? state->completed : state->movecount));
970 status_bar(fe, statusbuf);
974 static int game_wants_statusbar(void)
980 #define thegame twiddle
983 const struct game thegame = {
984 "Twiddle", "games.twiddle",
991 TRUE, game_configure, custom_params,
999 TRUE, game_text_format,
1006 game_free_drawstate,
1010 game_wants_statusbar,