ref: a1c88470a30cf57226aa091f546da18d0dff07e1
parent: 20921e613e78599dfbef2d805d3bf3dfad39a7e6
author: Simon Tatham <anakin@pobox.com>
date: Tue May 11 13:06:50 EDT 2004
Added a new game, `Rectangles', taken from nikoli.co.jp. [originally from svn r4206]
--- a/.cvsignore
+++ b/.cvsignore
@@ -1,5 +1,5 @@
Makefile*
-net cube fifteen sixteen nullgame
+net cube fifteen sixteen rect nullgame
*.exe *.obj *.o
*.map *.rsp
*notes
--- a/Recipe
+++ b/Recipe
@@ -20,11 +20,13 @@
cube : [X] gtk COMMON cube
fifteen : [X] gtk COMMON fifteen
sixteen : [X] gtk COMMON sixteen
+rect : [X] gtk COMMON rect
net : [G] WINDOWS COMMON NET
cube : [G] WINDOWS COMMON cube
fifteen : [G] WINDOWS COMMON fifteen
sixteen : [G] WINDOWS COMMON sixteen
+rect : [G] WINDOWS COMMON rect
# The `nullgame' source file is a largely blank one, which contains
# all the correct function definitions to compile and link, but
--- /dev/null
+++ b/rect.c
@@ -1,0 +1,1058 @@
+/*
+ * rect.c: Puzzle from nikoli.co.jp. You have a square grid with
+ * numbers in some squares; you must divide the square grid up into
+ * variously sized rectangles, such that every rectangle contains
+ * exactly one numbered square and the area of each rectangle is
+ * equal to the number contained in it.
+ */
+
+/*
+ * TODO:
+ *
+ * - Improve on singleton removal by making an aesthetic choice
+ * about which of the options to take.
+ *
+ * - When doing the 3x3 trick in singleton removal, limit the size
+ * of the generated rectangles in accordance with the max
+ * rectangle size.
+ *
+ * - It might be interesting to deliberately try to place
+ * numbers so as to reduce alternative solution patterns. I
+ * doubt we can do a perfect job of this, but we can make a
+ * start by, for example, noticing pairs of 2-rects
+ * alongside one another and _not_ putting their numbers at
+ * opposite ends.
+ *
+ * - If we start by sorting the rectlist in descending order
+ * of area, we might be able to bias our random number
+ * selection to produce a few large rectangles more often
+ * than oodles of small ones? Unsure, but might be worth a
+ * try.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <math.h>
+
+#include "puzzles.h"
+
+const char *const game_name = "Rectangles";
+const int game_can_configure = TRUE;
+
+enum {+ COL_BACKGROUND,
+ COL_CORRECT,
+ COL_LINE,
+ COL_TEXT,
+ COL_GRID,
+ NCOLOURS
+};
+
+struct game_params {+ int w, h;
+};
+
+#define INDEX(state, x, y) (((y) * (state)->w) + (x))
+#define index(state, a, x, y) ((a) [ INDEX(state,x,y) ])
+#define grid(state,x,y) index(state, (state)->grid, x, y)
+#define vedge(state,x,y) index(state, (state)->vedge, x, y)
+#define hedge(state,x,y) index(state, (state)->hedge, x, y)
+
+#define CRANGE(state,x,y,dx,dy) ( (x) >= dx && (x) < (state)->w && \
+ (y) >= dy && (y) < (state)->h )
+#define RANGE(state,x,y) CRANGE(state,x,y,0,0)
+#define HRANGE(state,x,y) CRANGE(state,x,y,0,1)
+#define VRANGE(state,x,y) CRANGE(state,x,y,1,0)
+
+#define TILE_SIZE 24
+#define BORDER 18
+
+#define COORD(x) ( (x) * TILE_SIZE + BORDER )
+#define FROMCOORD(x) ( ((x) - BORDER) / TILE_SIZE )
+
+struct game_state {+ int w, h;
+ int *grid; /* contains the numbers */
+ unsigned char *vedge; /* (w+1) x h */
+ unsigned char *hedge; /* w x (h+1) */
+};
+
+game_params *default_params(void)
+{+ game_params *ret = snew(game_params);
+
+ ret->w = ret->h = 7;
+
+ return ret;
+}
+
+int game_fetch_preset(int i, char **name, game_params **params)
+{+ game_params *ret;
+ int w, h;
+ char buf[80];
+
+ switch (i) {+ case 0: w = 7, h = 7; break;
+ case 1: w = 11, h = 11; break;
+ case 2: w = 15, h = 15; break;
+ case 3: w = 19, h = 19; break;
+ default: return FALSE;
+ }
+
+ sprintf(buf, "%dx%d", w, h);
+ *name = dupstr(buf);
+ *params = ret = snew(game_params);
+ ret->w = w;
+ ret->h = h;
+ return TRUE;
+}
+
+void free_params(game_params *params)
+{+ sfree(params);
+}
+
+game_params *dup_params(game_params *params)
+{+ game_params *ret = snew(game_params);
+ *ret = *params; /* structure copy */
+ return ret;
+}
+
+config_item *game_configure(game_params *params)
+{+ config_item *ret;
+ char buf[80];
+
+ ret = snewn(5, config_item);
+
+ ret[0].name = "Width";
+ ret[0].type = C_STRING;
+ sprintf(buf, "%d", params->w);
+ ret[0].sval = dupstr(buf);
+ ret[0].ival = 0;
+
+ ret[1].name = "Height";
+ ret[1].type = C_STRING;
+ sprintf(buf, "%d", params->h);
+ ret[1].sval = dupstr(buf);
+ ret[1].ival = 0;
+
+ ret[2].name = NULL;
+ ret[2].type = C_END;
+ ret[2].sval = NULL;
+ ret[2].ival = 0;
+
+ return ret;
+}
+
+game_params *custom_params(config_item *cfg)
+{+ game_params *ret = snew(game_params);
+
+ ret->w = atoi(cfg[0].sval);
+ ret->h = atoi(cfg[1].sval);
+
+ return ret;
+}
+
+char *validate_params(game_params *params)
+{+ if (params->w <= 0 && params->h <= 0)
+ return "Width and height must both be greater than zero";
+ if (params->w * params->h < 4)
+ return "Total area must be at least 4";
+ return NULL;
+}
+
+struct rect {+ int x, y;
+ int w, h;
+};
+
+struct rectlist {+ struct rect *rects;
+ int n;
+};
+
+static struct rectlist *get_rectlist(game_params *params, int *grid)
+{+ int rw, rh;
+ int x, y;
+ int maxarea;
+ struct rect *rects = NULL;
+ int nrects = 0, rectsize = 0;
+
+ /*
+ * Maximum rectangle area is 1/6 of total grid size.
+ */
+ maxarea = params->w * params->h / 6;
+
+ for (rw = 1; rw <= params->w; rw++)
+ for (rh = 1; rh <= params->h; rh++) {+ if (rw * rh > maxarea)
+ continue;
+ if (rw * rh == 1)
+ continue;
+ for (x = 0; x <= params->w - rw; x++)
+ for (y = 0; y <= params->h - rh; y++) {+ /*
+ * We have a candidate rectangle placement. See
+ * if it's unobstructed.
+ */
+ int xx, yy;
+ int ok;
+
+ ok = TRUE;
+ for (xx = x; xx < x+rw; xx++)
+ for (yy = y; yy < y+rh; yy++)
+ if (index(params, grid, xx, yy) >= 0) {+ ok = FALSE;
+ goto break1; /* break both loops at once */
+ }
+ break1:
+
+ if (!ok)
+ continue;
+
+ if (nrects >= rectsize) {+ rectsize = nrects + 256;
+ rects = sresize(rects, rectsize, struct rect);
+ }
+
+ rects[nrects].x = x;
+ rects[nrects].y = y;
+ rects[nrects].w = rw;
+ rects[nrects].h = rh;
+ nrects++;
+ }
+ }
+
+ if (nrects > 0) {+ struct rectlist *ret;
+ ret = snew(struct rectlist);
+ ret->rects = rects;
+ ret->n = nrects;
+ return ret;
+ } else {+ assert(rects == NULL); /* hence no need to free */
+ return NULL;
+ }
+}
+
+static void free_rectlist(struct rectlist *list)
+{+ sfree(list->rects);
+ sfree(list);
+}
+
+static void place_rect(game_params *params, int *grid, struct rect r)
+{+ int idx = INDEX(params, r.x, r.y);
+ int x, y;
+
+ for (x = r.x; x < r.x+r.w; x++)
+ for (y = r.y; y < r.y+r.h; y++) {+ index(params, grid, x, y) = idx;
+ }
+#ifdef GENERATION_DIAGNOSTICS
+ printf(" placing rectangle at (%d,%d) size %d x %d\n",+ r.x, r.y, r.w, r.h);
+#endif
+}
+
+static struct rect find_rect(game_params *params, int *grid, int x, int y)
+{+ int idx, w, h;
+ struct rect r;
+
+ /*
+ * Find the top left of the rectangle.
+ */
+ idx = index(params, grid, x, y);
+
+ if (idx < 0) {+ r.x = x;
+ r.y = y;
+ r.w = r.h = 1;
+ return r; /* 1x1 singleton here */
+ }
+
+ y = idx / params->w;
+ x = idx % params->w;
+
+ /*
+ * Find the width and height of the rectangle.
+ */
+ for (w = 1;
+ (x+w < params->w && index(params,grid,x+w,y)==idx);
+ w++);
+ for (h = 1;
+ (y+h < params->h && index(params,grid,x,y+h)==idx);
+ h++);
+
+ r.x = x;
+ r.y = y;
+ r.w = w;
+ r.h = h;
+
+ return r;
+}
+
+#ifdef GENERATION_DIAGNOSTICS
+static void display_grid(game_params *params, int *grid, int *numbers)
+{+ unsigned char *egrid = snewn((params->w*2+3) * (params->h*2+3),
+ unsigned char);
+ memset(egrid, 0, (params->w*2+3) * (params->h*2+3));
+ int x, y;
+ int r = (params->w*2+3);
+
+ for (x = 0; x < params->w; x++)
+ for (y = 0; y < params->h; y++) {+ int i = index(params, grid, x, y);
+ if (x == 0 || index(params, grid, x-1, y) != i)
+ egrid[(2*y+2) * r + (2*x+1)] = 1;
+ if (x == params->w-1 || index(params, grid, x+1, y) != i)
+ egrid[(2*y+2) * r + (2*x+3)] = 1;
+ if (y == 0 || index(params, grid, x, y-1) != i)
+ egrid[(2*y+1) * r + (2*x+2)] = 1;
+ if (y == params->h-1 || index(params, grid, x, y+1) != i)
+ egrid[(2*y+3) * r + (2*x+2)] = 1;
+ }
+
+ for (y = 1; y < 2*params->h+2; y++) {+ for (x = 1; x < 2*params->w+2; x++) {+ if (!((y|x)&1)) {+ int k = index(params, numbers, x/2-1, y/2-1);
+ if (k) printf("%2d", k); else printf(" ");+ } else if (!((y&x)&1)) {+ int v = egrid[y*r+x];
+ if ((y&1) && v) v = '-';
+ if ((x&1) && v) v = '|';
+ if (!v) v = ' ';
+ putchar(v);
+ if (!(x&1)) putchar(v);
+ } else {+ int c, d = 0;
+ if (egrid[y*r+(x+1)]) d |= 1;
+ if (egrid[(y-1)*r+x]) d |= 2;
+ if (egrid[y*r+(x-1)]) d |= 4;
+ if (egrid[(y+1)*r+x]) d |= 8;
+ c = " ??+?-++?+|+++++"[d];
+ putchar(c);
+ if (!(x&1)) putchar(c);
+ }
+ }
+ putchar('\n');+ }
+
+ sfree(egrid);
+}
+#endif
+
+char *new_game_seed(game_params *params, random_state *rs)
+{+ int *grid, *numbers;
+ struct rectlist *list;
+ int x, y, run, i;
+ char *seed, *p;
+
+ grid = snewn(params->w * params->h, int);
+ numbers = snewn(params->w * params->h, int);
+
+ for (y = 0; y < params->h; y++)
+ for (x = 0; x < params->w; x++) {+ index(params, grid, x, y) = -1;
+ index(params, numbers, x, y) = 0;
+ }
+
+ list = get_rectlist(params, grid);
+ assert(list != NULL);
+
+ /*
+ * Place rectangles until we can't any more.
+ */
+ while (list->n > 0) {+ int i, m;
+ struct rect r;
+
+ /*
+ * Pick a random rectangle.
+ */
+ i = random_upto(rs, list->n);
+ r = list->rects[i];
+
+ /*
+ * Place it.
+ */
+ place_rect(params, grid, r);
+
+ /*
+ * Winnow the list by removing any rectangles which
+ * overlap this one.
+ */
+ m = 0;
+ for (i = 0; i < list->n; i++) {+ struct rect s = list->rects[i];
+ if (s.x+s.w <= r.x || r.x+r.w <= s.x ||
+ s.y+s.h <= r.y || r.y+r.h <= s.y)
+ list->rects[m++] = s;
+ }
+ list->n = m;
+ }
+
+ free_rectlist(list);
+
+ /*
+ * Deal with singleton spaces remaining in the grid, one by
+ * one.
+ *
+ * We do this by making a local change to the layout. There are
+ * several possibilities:
+ *
+ * +-----+-----+ Here, we can remove the singleton by
+ * | | | extending the 1x2 rectangle below it
+ * +--+--+-----+ into a 1x3.
+ * | | | |
+ * | +--+ |
+ * | | | |
+ * | | | |
+ * | | | |
+ * +--+--+-----+
+ *
+ * +--+--+--+ Here, that trick doesn't work: there's no
+ * | | | 1 x n rectangle with the singleton at one
+ * | | | end. Instead, we extend a 1 x n rectangle
+ * | | | _out_ from the singleton, shaving a layer
+ * +--+--+ | off the end of another rectangle. So if we
+ * | | | | extended up, we'd make our singleton part
+ * | +--+--+ of a 1x3 and generate a 1x2 where the 2x2
+ * | | | used to be; or we could extend right into
+ * +--+-----+ a 2x1, turning the 1x3 into a 1x2.
+ *
+ * +-----+--+ Here, we can't even do _that_, since any
+ * | | | direction we choose to extend the singleton
+ * +--+--+ | will produce a new singleton as a result of
+ * | | | | truncating one of the size-2 rectangles.
+ * | +--+--+ Fortunately, this case can _only_ occur when
+ * | | | a singleton is surrounded by four size-2s
+ * +--+-----+ in this fashion; so instead we can simply
+ * replace the whole section with a single 3x3.
+ */
+ for (x = 0; x < params->w; x++) {+ for (y = 0; y < params->h; y++) {+ if (index(params, grid, x, y) < 0) {+ int dirs[4], ndirs;
+
+#ifdef GENERATION_DIAGNOSTICS
+ display_grid(params, grid, numbers);
+ printf("singleton at %d,%d\n", x, y);+#endif
+
+ /*
+ * Check in which directions we can feasibly extend
+ * the singleton. We can extend in a particular
+ * direction iff either:
+ *
+ * - the rectangle on that side of the singleton
+ * is not 2x1, and we are at one end of the edge
+ * of it we are touching
+ *
+ * - it is 2x1 but we are on its short side.
+ *
+ * FIXME: we could plausibly choose between these
+ * based on the sizes of the rectangles they would
+ * create?
+ */
+ ndirs = 0;
+ if (x < params->w-1) {+ struct rect r = find_rect(params, grid, x+1, y);
+ if ((r.w * r.h > 2 && (r.y==y || r.y+r.h-1==y)) || r.h==1)
+ dirs[ndirs++] = 1; /* right */
+ }
+ if (y > 0) {+ struct rect r = find_rect(params, grid, x, y-1);
+ if ((r.w * r.h > 2 && (r.x==x || r.x+r.w-1==x)) || r.w==1)
+ dirs[ndirs++] = 2; /* up */
+ }
+ if (x > 0) {+ struct rect r = find_rect(params, grid, x-1, y);
+ if ((r.w * r.h > 2 && (r.y==y || r.y+r.h-1==y)) || r.h==1)
+ dirs[ndirs++] = 4; /* left */
+ }
+ if (y < params->h-1) {+ struct rect r = find_rect(params, grid, x, y+1);
+ if ((r.w * r.h > 2 && (r.x==x || r.x+r.w-1==x)) || r.w==1)
+ dirs[ndirs++] = 8; /* down */
+ }
+
+ if (ndirs > 0) {+ int which, dir;
+ struct rect r1, r2;
+
+ which = random_upto(rs, ndirs);
+ dir = dirs[which];
+
+ switch (dir) {+ case 1: /* right */
+ assert(x < params->w+1);
+#ifdef GENERATION_DIAGNOSTICS
+ printf("extending right\n");+#endif
+ r1 = find_rect(params, grid, x+1, y);
+ r2.x = x;
+ r2.y = y;
+ r2.w = 1 + r1.w;
+ r2.h = 1;
+ if (r1.y == y)
+ r1.y++;
+ r1.h--;
+ break;
+ case 2: /* up */
+ assert(y > 0);
+#ifdef GENERATION_DIAGNOSTICS
+ printf("extending up\n");+#endif
+ r1 = find_rect(params, grid, x, y-1);
+ r2.x = x;
+ r2.y = r1.y;
+ r2.w = 1;
+ r2.h = 1 + r1.h;
+ if (r1.x == x)
+ r1.x++;
+ r1.w--;
+ break;
+ case 4: /* left */
+ assert(x > 0);
+#ifdef GENERATION_DIAGNOSTICS
+ printf("extending left\n");+#endif
+ r1 = find_rect(params, grid, x-1, y);
+ r2.x = r1.x;
+ r2.y = y;
+ r2.w = 1 + r1.w;
+ r2.h = 1;
+ if (r1.y == y)
+ r1.y++;
+ r1.h--;
+ break;
+ case 8: /* down */
+ assert(y < params->h+1);
+#ifdef GENERATION_DIAGNOSTICS
+ printf("extending down\n");+#endif
+ r1 = find_rect(params, grid, x, y+1);
+ r2.x = x;
+ r2.y = y;
+ r2.w = 1;
+ r2.h = 1 + r1.h;
+ if (r1.x == x)
+ r1.x++;
+ r1.w--;
+ break;
+ }
+ if (r1.h > 0 && r1.w > 0)
+ place_rect(params, grid, r1);
+ place_rect(params, grid, r2);
+ } else {+#ifndef NDEBUG
+ /*
+ * Sanity-check that there really is a 3x3
+ * rectangle surrounding this singleton and it
+ * contains absolutely everything we could
+ * possibly need.
+ */
+ {+ int xx, yy;
+ assert(x > 0 && x < params->w-1);
+ assert(y > 0 && y < params->h-1);
+
+ for (xx = x-1; xx <= x+1; xx++)
+ for (yy = y-1; yy <= y+1; yy++) {+ struct rect r = find_rect(params,grid,xx,yy);
+ assert(r.x >= x-1);
+ assert(r.y >= y-1);
+ assert(r.x+r.w-1 <= x+1);
+ assert(r.y+r.h-1 <= y+1);
+ }
+ }
+#endif
+
+#ifdef GENERATION_DIAGNOSTICS
+ printf("need the 3x3 trick\n");+#endif
+
+ /*
+ * FIXME: If the maximum rectangle area for
+ * this grid is less than 9, we ought to
+ * subdivide the 3x3 in some fashion. There are
+ * five other possibilities:
+ *
+ * - a 6 and a 3
+ * - a 4, a 3 and a 2
+ * - three 3s
+ * - a 3 and three 2s (two different arrangements).
+ */
+
+ {+ struct rect r;
+ r.x = x-1;
+ r.y = y-1;
+ r.w = r.h = 3;
+ place_rect(params, grid, r);
+ }
+ }
+ }
+ }
+ }
+
+ /*
+ * Place numbers.
+ */
+ for (x = 0; x < params->w; x++) {+ for (y = 0; y < params->h; y++) {+ int idx = INDEX(params, x, y);
+ if (index(params, grid, x, y) == idx) {+ struct rect r = find_rect(params, grid, x, y);
+ int n, xx, yy;
+
+ /*
+ * Decide where to put the number.
+ */
+ n = random_upto(rs, r.w*r.h);
+ yy = n / r.w;
+ xx = n % r.w;
+ index(params,numbers,x+xx,y+yy) = r.w*r.h;
+ }
+ }
+ }
+
+#ifdef GENERATION_DIAGNOSTICS
+ display_grid(params, grid, numbers);
+#endif
+
+ seed = snewn(11 * params->w * params->h, char);
+ p = seed;
+ run = 0;
+ for (i = 0; i <= params->w * params->h; i++) {+ int n = (i < params->w * params->h ? numbers[i] : -1);
+
+ if (!n)
+ run++;
+ else {+ if (run) {+ while (run > 0) {+ int c = 'a' - 1 + run;
+ if (run > 26)
+ c = 'z';
+ *p++ = c;
+ run -= c - ('a' - 1);+ }
+ } else {+ *p++ = '_';
+ }
+ if (n > 0)
+ p += sprintf(p, "%d", n);
+ run = 0;
+ }
+ }
+ *p = '\0';
+
+ sfree(grid);
+ sfree(numbers);
+
+ return seed;
+}
+
+char *validate_seed(game_params *params, char *seed)
+{+ int area = params->w * params->h;
+ int squares = 0;
+
+ while (*seed) {+ int n = *seed++;
+ if (n >= 'a' && n <= 'z') {+ squares += n - 'a' + 1;
+ } else if (n == '_') {+ /* do nothing */;
+ } else if (n > '0' && n <= '9') {+ squares += atoi(seed-1);
+ while (*seed >= '0' && *seed <= '9')
+ seed++;
+ } else
+ return "Invalid character in game specification";
+ }
+
+ if (squares < area)
+ return "Not enough data to fill grid";
+
+ if (squares > area)
+ return "Too much data to fit in grid";
+
+ return NULL;
+}
+
+game_state *new_game(game_params *params, char *seed)
+{+ game_state *state = snew(game_state);
+ int x, y, i, area;
+
+ state->w = params->w;
+ state->h = params->h;
+
+ area = state->w * state->h;
+
+ state->grid = snewn(area, int);
+ state->vedge = snewn(area, unsigned char);
+ state->hedge = snewn(area, unsigned char);
+
+ i = 0;
+ while (*seed) {+ int n = *seed++;
+ if (n >= 'a' && n <= 'z') {+ int run = n - 'a' + 1;
+ assert(i + run <= area);
+ while (run-- > 0)
+ state->grid[i++] = 0;
+ } else if (n == '_') {+ /* do nothing */;
+ } else if (n > '0' && n <= '9') {+ assert(i < area);
+ state->grid[i++] = atoi(seed-1);
+ while (*seed >= '0' && *seed <= '9')
+ seed++;
+ } else {+ assert(!"We can't get here");
+ }
+ }
+ assert(i == area);
+
+ for (y = 0; y < state->h; y++)
+ for (x = 0; x < state->w; x++)
+ vedge(state,x,y) = hedge(state,x,y) = 0;
+
+ return state;
+}
+
+game_state *dup_game(game_state *state)
+{+ game_state *ret = snew(game_state);
+
+ ret->w = state->w;
+ ret->h = state->h;
+
+ ret->vedge = snewn(state->w * state->h, unsigned char);
+ ret->hedge = snewn(state->w * state->h, unsigned char);
+ ret->grid = snewn(state->w * state->h, int);
+
+ memcpy(ret->grid, state->grid, state->w * state->h * sizeof(int));
+ memcpy(ret->vedge, state->vedge, state->w*state->h*sizeof(unsigned char));
+ memcpy(ret->hedge, state->hedge, state->w*state->h*sizeof(unsigned char));
+
+ return ret;
+}
+
+void free_game(game_state *state)
+{+ sfree(state->grid);
+ sfree(state->vedge);
+ sfree(state->hedge);
+ sfree(state);
+}
+
+static unsigned char *get_correct(game_state *state)
+{+ unsigned char *ret;
+ int x, y;
+
+ ret = snewn(state->w * state->h, unsigned char);
+ memset(ret, 0xFF, state->w * state->h);
+
+ for (x = 0; x < state->w; x++)
+ for (y = 0; y < state->h; y++)
+ if (index(state,ret,x,y) == 0xFF) {+ int rw, rh;
+ int xx, yy;
+ int num, area, valid;
+
+ /*
+ * Find a rectangle starting at this point.
+ */
+ rw = 1;
+ while (x+rw < state->w && !vedge(state,x+rw,y))
+ rw++;
+ rh = 1;
+ while (y+rh < state->h && !hedge(state,x,y+rh))
+ rh++;
+
+ /*
+ * We know what the dimensions of the rectangle
+ * should be if it's there at all. Find out if we
+ * really have a valid rectangle.
+ */
+ valid = TRUE;
+ /* Check the horizontal edges. */
+ for (xx = x; xx < x+rw; xx++) {+ for (yy = y; yy <= y+rh; yy++) {+ int e = !HRANGE(state,xx,yy) || hedge(state,xx,yy);
+ int ec = (yy == y || yy == y+rh);
+ if (e != ec)
+ valid = FALSE;
+ }
+ }
+ /* Check the vertical edges. */
+ for (yy = y; yy < y+rh; yy++) {+ for (xx = x; xx <= x+rw; xx++) {+ int e = !VRANGE(state,xx,yy) || vedge(state,xx,yy);
+ int ec = (xx == x || xx == x+rw);
+ if (e != ec)
+ valid = FALSE;
+ }
+ }
+
+ /*
+ * If this is not a valid rectangle with no other
+ * edges inside it, we just mark this square as not
+ * complete and proceed to the next square.
+ */
+ if (!valid) {+ index(state, ret, x, y) = 0;
+ continue;
+ }
+
+ /*
+ * We have a rectangle. Now see what its area is,
+ * and how many numbers are in it.
+ */
+ num = 0;
+ area = 0;
+ for (xx = x; xx < x+rw; xx++) {+ for (yy = y; yy < y+rh; yy++) {+ area++;
+ if (grid(state,xx,yy)) {+ if (num > 0)
+ valid = FALSE; /* two numbers */
+ num = grid(state,xx,yy);
+ }
+ }
+ }
+ if (num != area)
+ valid = FALSE;
+
+ /*
+ * Now fill in the whole rectangle based on the
+ * value of `valid'.
+ */
+ for (xx = x; xx < x+rw; xx++) {+ for (yy = y; yy < y+rh; yy++) {+ index(state, ret, xx, yy) = valid;
+ }
+ }
+ }
+
+ return ret;
+}
+
+game_state *make_move(game_state *from, int x, int y, int button)
+{+ float xf, yf, dx, dy;
+ int hxr, hyr, vxr, vyr;
+ game_state *ret;
+
+ if (button != LEFT_BUTTON)
+ return NULL;
+
+ xf = FROMCOORD(((float)x));
+ yf = FROMCOORD(((float)y));
+
+ hxr = (int)xf;
+ hyr = (int)(yf + 0.5F);
+
+ vxr = (int)(xf + 0.5F);
+ vyr = (int)yf;
+
+ dx = fabs(xf - vxr);
+ dy = fabs(yf - hyr);
+
+ if (dy < dx && HRANGE(from,hxr,hyr)) {+ ret = dup_game(from);
+ hedge(ret,hxr,hyr) = !hedge(ret,hxr,hyr);
+ return ret;
+ } else if (dx < dy && VRANGE(from,vxr,vyr)) {+ ret = dup_game(from);
+ vedge(ret,vxr,vyr) = !vedge(ret,vxr,vyr);
+ return ret;
+ }
+
+ return NULL;
+}
+
+/* ----------------------------------------------------------------------
+ * Drawing routines.
+ */
+
+#define L 1
+#define R 2
+#define U 4
+#define D 8
+#define CORRECT 16
+
+struct game_drawstate {+ int started;
+ int w, h;
+ unsigned char *visible;
+};
+
+void game_size(game_params *params, int *x, int *y)
+{+ *x = params->w * TILE_SIZE + 2*BORDER + 1;
+ *y = params->h * TILE_SIZE + 2*BORDER + 1;
+}
+
+float *game_colours(frontend *fe, game_state *state, int *ncolours)
+{+ float *ret = snewn(3 * NCOLOURS, float);
+
+ frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
+
+ ret[COL_GRID * 3 + 0] = 0.5F * ret[COL_BACKGROUND * 3 + 0];
+ ret[COL_GRID * 3 + 1] = 0.5F * ret[COL_BACKGROUND * 3 + 1];
+ ret[COL_GRID * 3 + 2] = 0.5F * ret[COL_BACKGROUND * 3 + 2];
+
+ ret[COL_CORRECT * 3 + 0] = 0.75F * ret[COL_BACKGROUND * 3 + 0];
+ ret[COL_CORRECT * 3 + 1] = 0.75F * ret[COL_BACKGROUND * 3 + 1];
+ ret[COL_CORRECT * 3 + 2] = 0.75F * ret[COL_BACKGROUND * 3 + 2];
+
+ ret[COL_LINE * 3 + 0] = 0.0F;
+ ret[COL_LINE * 3 + 1] = 0.0F;
+ ret[COL_LINE * 3 + 2] = 0.0F;
+
+ ret[COL_TEXT * 3 + 0] = 0.0F;
+ ret[COL_TEXT * 3 + 1] = 0.0F;
+ ret[COL_TEXT * 3 + 2] = 0.0F;
+
+ *ncolours = NCOLOURS;
+ return ret;
+}
+
+game_drawstate *game_new_drawstate(game_state *state)
+{+ struct game_drawstate *ds = snew(struct game_drawstate);
+
+ ds->started = FALSE;
+ ds->w = state->w;
+ ds->h = state->h;
+ ds->visible = snewn(ds->w * ds->h, unsigned char);
+ memset(ds->visible, 0xFF, ds->w * ds->h);
+
+ return ds;
+}
+
+void game_free_drawstate(game_drawstate *ds)
+{+ sfree(ds->visible);
+ sfree(ds);
+}
+
+void draw_tile(frontend *fe, game_state *state, int x, int y, int correct)
+{+ int cx = COORD(x), cy = COORD(y);
+ char str[80];
+
+ draw_rect(fe, cx, cy, TILE_SIZE+1, TILE_SIZE+1, COL_GRID);
+ draw_rect(fe, cx+1, cy+1, TILE_SIZE-1, TILE_SIZE-1,
+ correct ? COL_CORRECT : COL_BACKGROUND);
+
+ if (grid(state,x,y)) {+ sprintf(str, "%d", grid(state,x,y));
+ draw_text(fe, cx+TILE_SIZE/2, cy+TILE_SIZE/2, FONT_VARIABLE,
+ TILE_SIZE/3, ALIGN_HCENTRE | ALIGN_VCENTRE, COL_TEXT, str);
+ }
+
+ /*
+ * Draw edges.
+ */
+ if (!HRANGE(state,x,y) || hedge(state,x,y))
+ draw_rect(fe, cx, cy, TILE_SIZE+1, 2, COL_LINE);
+ if (!HRANGE(state,x,y+1) || hedge(state,x,y+1))
+ draw_rect(fe, cx, cy+TILE_SIZE-1, TILE_SIZE+1, 2, COL_LINE);
+ if (!VRANGE(state,x,y) || vedge(state,x,y))
+ draw_rect(fe, cx, cy, 2, TILE_SIZE+1, COL_LINE);
+ if (!VRANGE(state,x+1,y) || vedge(state,x+1,y))
+ draw_rect(fe, cx+TILE_SIZE-1, cy, 2, TILE_SIZE+1, COL_LINE);
+
+ /*
+ * Draw corners.
+ */
+ if ((HRANGE(state,x-1,y) && hedge(state,x-1,y)) ||
+ (VRANGE(state,x,y-1) && vedge(state,x,y-1)))
+ draw_rect(fe, cx, cy, 2, 2, COL_LINE);
+ if ((HRANGE(state,x+1,y) && hedge(state,x+1,y)) ||
+ (VRANGE(state,x+1,y-1) && vedge(state,x+1,y-1)))
+ draw_rect(fe, cx+TILE_SIZE-1, cy, 2, 2, COL_LINE);
+ if ((HRANGE(state,x-1,y+1) && hedge(state,x-1,y+1)) ||
+ (VRANGE(state,x,y+1) && vedge(state,x,y+1)))
+ draw_rect(fe, cx, cy+TILE_SIZE-1, 2, 2, COL_LINE);
+ if ((HRANGE(state,x+1,y+1) && hedge(state,x+1,y+1)) ||
+ (VRANGE(state,x+1,y+1) && vedge(state,x+1,y+1)))
+ draw_rect(fe, cx+TILE_SIZE-1, cy+TILE_SIZE-1, 2, 2, COL_LINE);
+
+ draw_update(fe, cx, cy, TILE_SIZE+1, TILE_SIZE+1);
+}
+
+void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate,
+ game_state *state, float animtime, float flashtime)
+{+ int x, y;
+ unsigned char *correct;
+
+ correct = get_correct(state);
+
+ if (!ds->started) {+ draw_rect(fe, COORD(0)-1, COORD(0)-1,
+ ds->w*TILE_SIZE+3, ds->h*TILE_SIZE+3, COL_LINE);
+ ds->started = TRUE;
+ }
+
+ for (x = 0; x < state->w; x++)
+ for (y = 0; y < state->h; y++) {+ unsigned char c = 0;
+
+ if (!HRANGE(state,x,y) || hedge(state,x,y))
+ c |= L;
+ if (!HRANGE(state,x+1,y) || hedge(state,x+1,y))
+ c |= R;
+ if (!VRANGE(state,x,y) || vedge(state,x,y))
+ c |= U;
+ if (!VRANGE(state,x,y+1) || vedge(state,x,y+1))
+ c |= D;
+ if (index(state, correct, x, y))
+ c |= CORRECT;
+
+ if (index(ds,ds->visible,x,y) != c) {+ draw_tile(fe, state, x, y, c & CORRECT);
+ //index(ds,ds->visible,x,y) = c;
+ }
+ }
+
+ sfree(correct);
+}
+
+float game_anim_length(game_state *oldstate, game_state *newstate)
+{+ return 0.0F;
+}
+
+float game_flash_length(game_state *oldstate, game_state *newstate)
+{+ return 0.0F;
+}
+
+int game_wants_statusbar(void)
+{+ return FALSE;
+}