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)
297 int w = params->w, h = params->h, n = params->n, wh = w*h;
304 * Set up a solved grid.
306 grid = snewn(wh, int);
307 for (i = 0; i < wh; i++)
308 grid[i] = ((params->rowsonly ? i/w : i) + 1) * 4;
311 * Shuffle it. This game is complex enough that I don't feel up
312 * to analysing its full symmetry properties (particularly at
313 * n=4 and above!), so I'm going to do it the pedestrian way
314 * and simply shuffle the grid by making a long sequence of
315 * randomly chosen moves.
317 total_moves = w*h*n*n*2;
318 for (i = 0; i < total_moves; i++) {
321 x = random_upto(rs, w - n + 1);
322 y = random_upto(rs, h - n + 1);
323 do_rotate(grid, w, h, n, params->orientable,
324 x, y, 1 + random_upto(rs, 3));
327 * Optionally one more move in case the entire grid has
328 * happened to come out solved.
330 if (i == total_moves - 1 && grid_complete(grid, wh,
336 * Now construct the game seed, by describing the grid as a
337 * simple sequence of integers. They're comma-separated, unless
338 * the puzzle is orientable in which case they're separated by
339 * orientation letters `u', `d', `l' and `r'.
343 for (i = 0; i < wh; i++) {
347 k = sprintf(buf, "%d%c", grid[i] / 4,
348 params->orientable ? "uldr"[grid[i] & 3] : ',');
350 ret = sresize(ret, retlen + k + 1, char);
351 strcpy(ret + retlen, buf);
354 if (!params->orientable)
355 ret[retlen-1] = '\0'; /* delete last comma */
361 static char *validate_seed(game_params *params, char *seed)
364 int w = params->w, h = params->h, wh = w*h;
370 for (i = 0; i < wh; i++) {
371 if (*p < '0' || *p > '9')
372 return "Not enough numbers in string";
373 while (*p >= '0' && *p <= '9')
375 if (!params->orientable && i < wh-1) {
377 return "Expected comma after number";
378 } else if (params->orientable && i < wh) {
379 if (*p != 'l' && *p != 'r' && *p != 'u' && *p != 'd')
380 return "Expected orientation letter after number";
381 } else if (i == wh-1 && *p) {
382 return "Excess junk at end of string";
385 if (*p) p++; /* eat comma */
391 static game_state *new_game(game_params *params, char *seed)
393 game_state *state = snew(game_state);
394 int w = params->w, h = params->h, n = params->n, wh = w*h;
401 state->orientable = params->orientable;
402 state->completed = 0;
403 state->movecount = 0;
404 state->lastx = state->lasty = state->lastr = -1;
406 state->grid = snewn(wh, int);
410 for (i = 0; i < wh; i++) {
411 state->grid[i] = 4 * atoi(p);
412 while (*p >= '0' && *p <= '9')
415 if (params->orientable) {
417 case 'l': state->grid[i] |= 1; break;
418 case 'd': state->grid[i] |= 2; break;
419 case 'r': state->grid[i] |= 3; break;
429 static game_state *dup_game(game_state *state)
431 game_state *ret = snew(game_state);
436 ret->orientable = state->orientable;
437 ret->completed = state->completed;
438 ret->movecount = state->movecount;
439 ret->lastx = state->lastx;
440 ret->lasty = state->lasty;
441 ret->lastr = state->lastr;
443 ret->grid = snewn(ret->w * ret->h, int);
444 memcpy(ret->grid, state->grid, ret->w * ret->h * sizeof(int));
449 static void free_game(game_state *state)
455 static game_ui *new_ui(game_state *state)
460 static void free_ui(game_ui *ui)
464 static game_state *make_move(game_state *from, game_ui *ui, int x, int y,
467 int w = from->w, h = from->h, n = from->n, wh = w*h;
471 if (button == LEFT_BUTTON || button == RIGHT_BUTTON) {
473 * Determine the coordinates of the click. We offset by n-1
474 * half-blocks so that the user must click at the centre of
475 * a rotation region rather than at the corner.
477 x -= (n-1) * TILE_SIZE / 2;
478 y -= (n-1) * TILE_SIZE / 2;
481 if (x < 0 || x > w-n || y < 0 || y > w-n)
485 * This is a valid move. Make it.
487 ret = dup_game(from);
489 dir = (button == LEFT_BUTTON ? 1 : -1);
490 do_rotate(ret->grid, w, h, n, ret->orientable, x, y, dir);
496 * See if the game has been completed. To do this we simply
497 * test that the grid contents are in increasing order.
499 if (!ret->completed && grid_complete(ret->grid, wh, ret->orientable))
500 ret->completed = ret->movecount;
506 /* ----------------------------------------------------------------------
510 struct game_drawstate {
516 static void game_size(game_params *params, int *x, int *y)
518 *x = TILE_SIZE * params->w + 2 * BORDER;
519 *y = TILE_SIZE * params->h + 2 * BORDER;
522 static float *game_colours(frontend *fe, game_state *state, int *ncolours)
524 float *ret = snewn(3 * NCOLOURS, float);
528 frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
531 * Drop the background colour so that the highlight is
532 * noticeably brighter than it while still being under 1.
534 max = ret[COL_BACKGROUND*3];
535 for (i = 1; i < 3; i++)
536 if (ret[COL_BACKGROUND*3+i] > max)
537 max = ret[COL_BACKGROUND*3+i];
538 if (max * 1.2F > 1.0F) {
539 for (i = 0; i < 3; i++)
540 ret[COL_BACKGROUND*3+i] /= (max * 1.2F);
543 for (i = 0; i < 3; i++) {
544 ret[COL_HIGHLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 1.2F;
545 ret[COL_HIGHLIGHT_GENTLE * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 1.1F;
546 ret[COL_LOWLIGHT * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 0.8F;
547 ret[COL_LOWLIGHT_GENTLE * 3 + i] = ret[COL_BACKGROUND * 3 + i] * 0.9F;
548 ret[COL_TEXT * 3 + i] = 0.0;
551 *ncolours = NCOLOURS;
555 static game_drawstate *game_new_drawstate(game_state *state)
557 struct game_drawstate *ds = snew(struct game_drawstate);
563 ds->bgcolour = COL_BACKGROUND;
564 ds->grid = snewn(ds->w*ds->h, int);
565 for (i = 0; i < ds->w*ds->h; i++)
571 static void game_free_drawstate(game_drawstate *ds)
577 int cx, cy, cw, ch; /* clip region */
578 int ox, oy; /* rotation origin */
579 float c, s; /* cos and sin of rotation angle */
580 int lc, rc, tc, bc; /* colours of tile edges */
583 static void rotate(int *xy, struct rotation *rot)
586 float xf = xy[0] - rot->ox, yf = xy[1] - rot->oy;
589 xf2 = rot->c * xf + rot->s * yf;
590 yf2 = - rot->s * xf + rot->c * yf;
592 xy[0] = xf2 + rot->ox + 0.5; /* round to nearest */
593 xy[1] = yf2 + rot->oy + 0.5; /* round to nearest */
597 static void draw_tile(frontend *fe, game_state *state, int x, int y,
598 int tile, int flash_colour, struct rotation *rot)
604 clip(fe, rot->cx, rot->cy, rot->cw, rot->ch);
607 * We must draw each side of the tile's highlight separately,
608 * because in some cases (during rotation) they will all need
609 * to be different colours.
612 /* The centre point is common to all sides. */
613 coords[4] = x + TILE_SIZE / 2;
614 coords[5] = y + TILE_SIZE / 2;
615 rotate(coords+4, rot);
618 coords[0] = x + TILE_SIZE - 1;
619 coords[1] = y + TILE_SIZE - 1;
620 rotate(coords+0, rot);
621 coords[2] = x + TILE_SIZE - 1;
623 rotate(coords+2, rot);
624 draw_polygon(fe, coords, 3, TRUE, rot ? rot->rc : COL_LOWLIGHT);
625 draw_polygon(fe, coords, 3, FALSE, rot ? rot->rc : COL_LOWLIGHT);
629 coords[3] = y + TILE_SIZE - 1;
630 rotate(coords+2, rot);
631 draw_polygon(fe, coords, 3, TRUE, rot ? rot->bc : COL_LOWLIGHT);
632 draw_polygon(fe, coords, 3, FALSE, rot ? rot->bc : COL_LOWLIGHT);
637 rotate(coords+0, rot);
638 draw_polygon(fe, coords, 3, TRUE, rot ? rot->lc : COL_HIGHLIGHT);
639 draw_polygon(fe, coords, 3, FALSE, rot ? rot->lc : COL_HIGHLIGHT);
642 coords[2] = x + TILE_SIZE - 1;
644 rotate(coords+2, rot);
645 draw_polygon(fe, coords, 3, TRUE, rot ? rot->tc : COL_HIGHLIGHT);
646 draw_polygon(fe, coords, 3, FALSE, rot ? rot->tc : COL_HIGHLIGHT);
649 * Now the main blank area in the centre of the tile.
652 coords[0] = x + HIGHLIGHT_WIDTH;
653 coords[1] = y + HIGHLIGHT_WIDTH;
654 rotate(coords+0, rot);
655 coords[2] = x + HIGHLIGHT_WIDTH;
656 coords[3] = y + TILE_SIZE - 1 - HIGHLIGHT_WIDTH;
657 rotate(coords+2, rot);
658 coords[4] = x + TILE_SIZE - 1 - HIGHLIGHT_WIDTH;
659 coords[5] = y + TILE_SIZE - 1 - HIGHLIGHT_WIDTH;
660 rotate(coords+4, rot);
661 coords[6] = x + TILE_SIZE - 1 - HIGHLIGHT_WIDTH;
662 coords[7] = y + HIGHLIGHT_WIDTH;
663 rotate(coords+6, rot);
664 draw_polygon(fe, coords, 4, TRUE, flash_colour);
665 draw_polygon(fe, coords, 4, FALSE, flash_colour);
667 draw_rect(fe, x + HIGHLIGHT_WIDTH, y + HIGHLIGHT_WIDTH,
668 TILE_SIZE - 2*HIGHLIGHT_WIDTH, TILE_SIZE - 2*HIGHLIGHT_WIDTH,
673 * Next, the colour bars for orientation.
675 if (state->orientable) {
676 int xdx, xdy, ydx, ydy;
677 int cx, cy, displ, displ2;
691 default /* case 3 */:
697 cx = x + TILE_SIZE / 2;
698 cy = y + TILE_SIZE / 2;
699 displ = TILE_SIZE / 2 - HIGHLIGHT_WIDTH - 2;
700 displ2 = TILE_SIZE / 3 - HIGHLIGHT_WIDTH;
702 coords[0] = cx - displ * xdx + displ2 * ydx;
703 coords[1] = cy - displ * xdy + displ2 * ydy;
704 rotate(coords+0, rot);
705 coords[2] = cx + displ * xdx + displ2 * ydx;
706 coords[3] = cy + displ * xdy + displ2 * ydy;
707 rotate(coords+2, rot);
708 coords[4] = cx - displ * ydx;
709 coords[5] = cy - displ * ydy;
710 rotate(coords+4, rot);
711 draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT_GENTLE);
712 draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT_GENTLE);
715 coords[0] = x + TILE_SIZE/2;
716 coords[1] = y + TILE_SIZE/2;
717 rotate(coords+0, rot);
718 sprintf(str, "%d", tile / 4);
719 draw_text(fe, coords[0], coords[1],
720 FONT_VARIABLE, TILE_SIZE/3, ALIGN_VCENTRE | ALIGN_HCENTRE,
726 draw_update(fe, x, y, TILE_SIZE, TILE_SIZE);
729 static int highlight_colour(float angle)
736 COL_HIGHLIGHT_GENTLE,
737 COL_HIGHLIGHT_GENTLE,
738 COL_HIGHLIGHT_GENTLE,
749 COL_HIGHLIGHT_GENTLE,
750 COL_HIGHLIGHT_GENTLE,
751 COL_HIGHLIGHT_GENTLE,
766 return colours[(int)((angle + 2*PI) / (PI/16)) & 31];
769 static float game_anim_length(game_state *oldstate, game_state *newstate,
772 return ANIM_PER_RADIUS_UNIT * sqrt(newstate->n-1);
775 static float game_flash_length(game_state *oldstate, game_state *newstate,
778 if (!oldstate->completed && newstate->completed)
779 return 2 * FLASH_FRAME;
784 static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate,
785 game_state *state, int dir, game_ui *ui,
786 float animtime, float flashtime)
789 struct rotation srot, *rot;
790 int lastx = -1, lasty = -1, lastr = -1;
793 int frame = (int)(flashtime / FLASH_FRAME);
794 bgcolour = (frame % 2 ? COL_LOWLIGHT : COL_HIGHLIGHT);
796 bgcolour = COL_BACKGROUND;
802 TILE_SIZE * state->w + 2 * BORDER,
803 TILE_SIZE * state->h + 2 * BORDER, COL_BACKGROUND);
804 draw_update(fe, 0, 0,
805 TILE_SIZE * state->w + 2 * BORDER,
806 TILE_SIZE * state->h + 2 * BORDER);
809 * Recessed area containing the whole puzzle.
811 coords[0] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
812 coords[1] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
813 coords[2] = COORD(state->w) + HIGHLIGHT_WIDTH - 1;
814 coords[3] = COORD(0) - HIGHLIGHT_WIDTH;
815 coords[4] = COORD(0) - HIGHLIGHT_WIDTH;
816 coords[5] = COORD(state->h) + HIGHLIGHT_WIDTH - 1;
817 draw_polygon(fe, coords, 3, TRUE, COL_HIGHLIGHT);
818 draw_polygon(fe, coords, 3, FALSE, COL_HIGHLIGHT);
820 coords[1] = COORD(0) - HIGHLIGHT_WIDTH;
821 coords[0] = COORD(0) - HIGHLIGHT_WIDTH;
822 draw_polygon(fe, coords, 3, TRUE, COL_LOWLIGHT);
823 draw_polygon(fe, coords, 3, FALSE, COL_LOWLIGHT);
829 * If we're drawing any rotated tiles, sort out the rotation
830 * parameters, and also zap the rotation region to the
831 * background colour before doing anything else.
835 float anim_max = game_anim_length(oldstate, state, dir);
838 lastx = state->lastx;
839 lasty = state->lasty;
840 lastr = state->lastr;
842 lastx = oldstate->lastx;
843 lasty = oldstate->lasty;
844 lastr = -oldstate->lastr;
848 rot->cx = COORD(lastx);
849 rot->cy = COORD(lasty);
850 rot->cw = rot->ch = TILE_SIZE * state->n;
851 rot->ox = rot->cx + rot->cw/2;
852 rot->oy = rot->cy + rot->ch/2;
853 angle = (-PI/2 * lastr) * (1.0 - animtime / anim_max);
858 * Sort out the colours of the various sides of the tile.
860 rot->lc = highlight_colour(PI + angle);
861 rot->rc = highlight_colour(angle);
862 rot->tc = highlight_colour(PI/2 + angle);
863 rot->bc = highlight_colour(-PI/2 + angle);
865 draw_rect(fe, rot->cx, rot->cy, rot->cw, rot->ch, bgcolour);
870 * Now draw each tile.
872 for (i = 0; i < state->w * state->h; i++) {
874 int tx = i % state->w, ty = i / state->w;
877 * Figure out what should be displayed at this location.
878 * Usually it will be state->grid[i], unless we're in the
879 * middle of animating an actual rotation and this cell is
880 * within the rotation region, in which case we set -1
883 if (oldstate && lastx >= 0 && lasty >= 0 &&
884 tx >= lastx && tx < lastx + state->n &&
885 ty >= lasty && ty < lasty + state->n)
890 if (ds->bgcolour != bgcolour || /* always redraw when flashing */
891 ds->grid[i] != t || ds->grid[i] == -1 || t == -1) {
892 int x = COORD(tx), y = COORD(ty);
894 draw_tile(fe, state, x, y, state->grid[i], bgcolour, rot);
898 ds->bgcolour = bgcolour;
901 * Update the status bar.
907 * Don't show the new status until we're also showing the
908 * new _state_ - after the game animation is complete.
913 sprintf(statusbuf, "%sMoves: %d",
914 (state->completed ? "COMPLETED! " : ""),
915 (state->completed ? state->completed : state->movecount));
917 status_bar(fe, statusbuf);
921 static int game_wants_statusbar(void)
927 #define thegame twiddle
930 const struct game thegame = {
931 "Twiddle", "games.twiddle",
938 TRUE, game_configure, custom_params,
955 game_wants_statusbar,