+/*
+ * slant.c: Puzzle from nikoli.co.jp involving drawing a diagonal
+ * line through each square of a grid.
+ */
+
+/*
+ * In this puzzle you have a grid of squares, each of which must
+ * contain a diagonal line; you also have clue numbers placed at
+ * _points_ of that grid, which means there's a (w+1) x (h+1) array
+ * of possible clue positions.
+ *
+ * I'm therefore going to adopt a rigid convention throughout this
+ * source file of using w and h for the dimensions of the grid of
+ * squares, and W and H for the dimensions of the grid of points.
+ * Thus, W == w+1 and H == h+1 always.
+ *
+ * Clue arrays will be W*H `signed char's, and the clue at each
+ * point will be a number from 0 to 4, or -1 if there's no clue.
+ *
+ * Solution arrays will be W*H `signed char's, and the number at
+ * each point will be +1 for a forward slash (/), -1 for a
+ * backslash (\), and 0 for unknown.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <ctype.h>
+#include <math.h>
+
+#include "puzzles.h"
+
+enum {
+ COL_BACKGROUND,
+ COL_GRID,
+ COL_INK,
+ NCOLOURS
+};
+
+struct game_params {
+ int w, h;
+};
+
+typedef struct game_clues {
+ int w, h;
+ signed char *clues;
+ int *dsf; /* scratch space for completion check */
+ int refcount;
+} game_clues;
+
+struct game_state {
+ struct game_params p;
+ game_clues *clues;
+ signed char *soln;
+ int completed;
+ int used_solve; /* used to suppress completion flash */
+};
+
+static game_params *default_params(void)
+{
+ game_params *ret = snew(game_params);
+
+ ret->w = ret->h = 8;
+
+ return ret;
+}
+
+static const struct game_params slant_presets[] = {
+ {5, 5},
+ {8, 8},
+ {12, 10},
+};
+
+static int game_fetch_preset(int i, char **name, game_params **params)
+{
+ game_params *ret;
+ char str[80];
+
+ if (i < 0 || i >= lenof(slant_presets))
+ return FALSE;
+
+ ret = snew(game_params);
+ *ret = slant_presets[i];
+
+ sprintf(str, "%dx%d", ret->w, ret->h);
+
+ *name = dupstr(str);
+ *params = ret;
+ return TRUE;
+}
+
+static void free_params(game_params *params)
+{
+ sfree(params);
+}
+
+static game_params *dup_params(game_params *params)
+{
+ game_params *ret = snew(game_params);
+ *ret = *params; /* structure copy */
+ return ret;
+}
+
+static void decode_params(game_params *ret, char const *string)
+{
+ ret->w = ret->h = atoi(string);
+ while (*string && isdigit((unsigned char)*string)) string++;
+ if (*string == 'x') {
+ string++;
+ ret->h = atoi(string);
+ }
+}
+
+static char *encode_params(game_params *params, int full)
+{
+ char data[256];
+
+ sprintf(data, "%dx%d", params->w, params->h);
+
+ return dupstr(data);
+}
+
+static config_item *game_configure(game_params *params)
+{
+ config_item *ret;
+ char buf[80];
+
+ ret = snewn(3, 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;
+}
+
+static 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;
+}
+
+static char *validate_params(game_params *params, int full)
+{
+ /*
+ * (At least at the time of writing this comment) The grid
+ * generator is actually capable of handling even zero grid
+ * dimensions without crashing. Puzzles with a zero-area grid
+ * are a bit boring, though, because they're already solved :-)
+ */
+
+ if (params->w < 1 || params->h < 1)
+ return "Width and height must both be at least one";
+
+ return NULL;
+}
+
+/*
+ * Utility function used by both the solver and the filled-grid
+ * generator.
+ */
+
+static void fill_square(int w, int h, int y, int x, int v,
+ signed char *soln, int *dsf)
+{
+ int W = w+1 /*, H = h+1 */;
+
+ soln[y*w+x] = v;
+
+ if (v < 0)
+ dsf_merge(dsf, y*W+x, (y+1)*W+(x+1));
+ else
+ dsf_merge(dsf, y*W+(x+1), (y+1)*W+x);
+}
+
+/*
+ * Scratch space for solver.
+ */
+struct solver_scratch {
+ int *dsf;
+};
+
+struct solver_scratch *new_scratch(int w, int h)
+{
+ int W = w+1, H = h+1;
+ struct solver_scratch *ret = snew(struct solver_scratch);
+ ret->dsf = snewn(W*H, int);
+ return ret;
+}
+
+void free_scratch(struct solver_scratch *sc)
+{
+ sfree(sc->dsf);
+ sfree(sc);
+}
+
+/*
+ * Solver. Returns 0 for impossibility, 1 for success, 2 for
+ * ambiguity or failure to converge.
+ */
+static int slant_solve(int w, int h, const signed char *clues,
+ signed char *soln, struct solver_scratch *sc)
+{
+ int W = w+1, H = h+1;
+ int x, y, i;
+ int done_something;
+
+ /*
+ * Clear the output.
+ */
+ memset(soln, 0, w*h);
+
+ /*
+ * Establish a disjoint set forest for tracking connectedness
+ * between grid points.
+ */
+ for (i = 0; i < W*H; i++)
+ sc->dsf[i] = i; /* initially all distinct */
+
+ /*
+ * Repeatedly try to deduce something until we can't.
+ */
+ do {
+ done_something = FALSE;
+
+ /*
+ * Any clue point with the number of remaining lines equal
+ * to zero or to the number of remaining undecided
+ * neighbouring squares can be filled in completely.
+ */
+ for (y = 0; y < H; y++)
+ for (x = 0; x < W; x++) {
+ int nu, nl, v, c;
+
+ if ((c = clues[y*W+x]) < 0)
+ continue;
+
+ /*
+ * We have a clue point. Count up the number of
+ * undecided neighbours, and also the number of
+ * lines already present.
+ */
+ nu = 0;
+ nl = c;
+ if (x > 0 && y > 0 && (v = soln[(y-1)*w+(x-1)]) != +1)
+ v == 0 ? nu++ : nl--;
+ if (x > 0 && y < h && (v = soln[y*w+(x-1)]) != -1)
+ v == 0 ? nu++ : nl--;
+ if (x < w && y > 0 && (v = soln[(y-1)*w+x]) != -1)
+ v == 0 ? nu++ : nl--;
+ if (x < w && y < h && (v = soln[y*w+x]) != +1)
+ v == 0 ? nu++ : nl--;
+
+ /*
+ * Check the counts.
+ */
+ if (nl < 0 || nl > nu) {
+ /*
+ * No consistent value for this at all!
+ */
+ return 0; /* impossible */
+ }
+
+ if (nu > 0 && (nl == 0 || nl == nu)) {
+#ifdef SOLVER_DIAGNOSTICS
+ printf("%s around clue point at %d,%d\n",
+ nl ? "filling" : "emptying", x, y);
+#endif
+ if (x > 0 && y > 0 && soln[(y-1)*w+(x-1)] == 0)
+ fill_square(w, h, y-1, x-1, (nl ? -1 : +1), soln,
+ sc->dsf);
+ if (x > 0 && y < h && soln[y*w+(x-1)] == 0)
+ fill_square(w, h, y, x-1, (nl ? +1 : -1), soln,
+ sc->dsf);
+ if (x < w && y > 0 && soln[(y-1)*w+x] == 0)
+ fill_square(w, h, y-1, x, (nl ? +1 : -1), soln,
+ sc->dsf);
+ if (x < w && y < h && soln[y*w+x] == 0)
+ fill_square(w, h, y, x, (nl ? -1 : +1), soln,
+ sc->dsf);
+
+ done_something = TRUE;
+ }
+ }
+
+ if (done_something)
+ continue;
+
+ /*
+ * Failing that, we now apply the second condition, which
+ * is that no square may be filled in such a way as to form
+ * a loop.
+ */
+ for (y = 0; y < h; y++)
+ for (x = 0; x < w; x++) {
+ int fs, bs;
+
+ if (soln[y*w+x])
+ continue; /* got this one already */
+
+ fs = (dsf_canonify(sc->dsf, y*W+x) ==
+ dsf_canonify(sc->dsf, (y+1)*W+(x+1)));
+ bs = (dsf_canonify(sc->dsf, (y+1)*W+x) ==
+ dsf_canonify(sc->dsf, y*W+(x+1)));
+
+ if (fs && bs) {
+ /*
+ * Loop avoidance leaves no consistent value
+ * for this at all!
+ */
+ return 0; /* impossible */
+ }
+
+ if (fs) {
+ /*
+ * Top left and bottom right corners of this
+ * square are already connected, which means we
+ * aren't allowed to put a backslash in here.
+ */
+#ifdef SOLVER_DIAGNOSTICS
+ printf("placing / in %d,%d by loop avoidance\n", x, y);
+#endif
+ fill_square(w, h, y, x, +1, soln, sc->dsf);
+ done_something = TRUE;
+ } else if (bs) {
+ /*
+ * Top right and bottom left corners of this
+ * square are already connected, which means we
+ * aren't allowed to put a forward slash in
+ * here.
+ */
+#ifdef SOLVER_DIAGNOSTICS
+ printf("placing \\ in %d,%d by loop avoidance\n", x, y);
+#endif
+ fill_square(w, h, y, x, -1, soln, sc->dsf);
+ done_something = TRUE;
+ }
+ }
+
+ } while (done_something);
+
+ /*
+ * Solver can make no more progress. See if the grid is full.
+ */
+ for (i = 0; i < w*h; i++)
+ if (!soln[i])
+ return 2; /* failed to converge */
+ return 1; /* success */
+}
+
+/*
+ * Filled-grid generator.
+ */
+static void slant_generate(int w, int h, signed char *soln, random_state *rs)
+{
+ int W = w+1, H = h+1;
+ int x, y, i;
+ int *dsf, *indices;
+
+ /*
+ * Clear the output.
+ */
+ memset(soln, 0, w*h);
+
+ /*
+ * Establish a disjoint set forest for tracking connectedness
+ * between grid points.
+ */
+ dsf = snewn(W*H, int);
+ for (i = 0; i < W*H; i++)
+ dsf[i] = i; /* initially all distinct */
+
+ /*
+ * Prepare a list of the squares in the grid, and fill them in
+ * in a random order.
+ */
+ indices = snewn(w*h, int);
+ for (i = 0; i < w*h; i++)
+ indices[i] = i;
+ shuffle(indices, w*h, sizeof(*indices), rs);
+
+ /*
+ * Fill in each one in turn.
+ */
+ for (i = 0; i < w*h; i++) {
+ int fs, bs, v;
+
+ y = indices[i] / w;
+ x = indices[i] % w;
+
+ fs = (dsf_canonify(dsf, y*W+x) ==
+ dsf_canonify(dsf, (y+1)*W+(x+1)));
+ bs = (dsf_canonify(dsf, (y+1)*W+x) ==
+ dsf_canonify(dsf, y*W+(x+1)));
+
+ /*
+ * It isn't possible to get into a situation where we
+ * aren't allowed to place _either_ type of slash in a
+ * square.
+ *
+ * Proof (thanks to Gareth Taylor):
+ *
+ * If it were possible, it would have to be because there
+ * was an existing path (not using this square) between the
+ * top-left and bottom-right corners of this square, and
+ * another between the other two. These two paths would
+ * have to cross at some point.
+ *
+ * Obviously they can't cross in the middle of a square, so
+ * they must cross by sharing a point in common. But this
+ * isn't possible either: if you chessboard-colour all the
+ * points on the grid, you find that any continuous
+ * diagonal path is entirely composed of points of the same
+ * colour. And one of our two hypothetical paths is between
+ * two black points, and the other is between two white
+ * points - therefore they can have no point in common. []
+ */
+ assert(!(fs && bs));
+
+ v = fs ? +1 : bs ? -1 : 2 * random_upto(rs, 2) - 1;
+ fill_square(w, h, y, x, v, soln, dsf);
+ }
+
+ sfree(indices);
+ sfree(dsf);
+}
+
+static char *new_game_desc(game_params *params, random_state *rs,
+ char **aux, int interactive)
+{
+ int w = params->w, h = params->h, W = w+1, H = h+1;
+ signed char *soln, *tmpsoln, *clues;
+ int *clueindices;
+ struct solver_scratch *sc;
+ int x, y, v, i;
+ char *desc;
+
+ soln = snewn(w*h, signed char);
+ tmpsoln = snewn(w*h, signed char);
+ clues = snewn(W*H, signed char);
+ clueindices = snewn(W*H, int);
+ sc = new_scratch(w, h);
+
+ do {
+ /*
+ * Create the filled grid.
+ */
+ slant_generate(w, h, soln, rs);
+
+ /*
+ * Fill in the complete set of clues.
+ */
+ for (y = 0; y < H; y++)
+ for (x = 0; x < W; x++) {
+ v = 0;
+
+ if (x > 0 && y > 0 && soln[(y-1)*w+(x-1)] == -1) v++;
+ if (x > 0 && y < h && soln[y*w+(x-1)] == +1) v++;
+ if (x < w && y > 0 && soln[(y-1)*w+x] == +1) v++;
+ if (x < w && y < h && soln[y*w+x] == -1) v++;
+
+ clues[y*W+x] = v;
+ }
+ } while (slant_solve(w, h, clues, tmpsoln, sc) != 1);
+
+ /*
+ * Remove as many clues as possible while retaining solubility.
+ */
+ for (i = 0; i < W*H; i++)
+ clueindices[i] = i;
+ shuffle(clueindices, W*H, sizeof(*clueindices), rs);
+ for (i = 0; i < W*H; i++) {
+ y = clueindices[i] / W;
+ x = clueindices[i] % W;
+ v = clues[y*W+x];
+ clues[y*W+x] = -1;
+ if (slant_solve(w, h, clues, tmpsoln, sc) != 1)
+ clues[y*W+x] = v; /* put it back */
+ }
+
+ /*
+ * Now we have the clue set as it will be presented to the
+ * user. Encode it in a game desc.
+ */
+ {
+ char *p;
+ int run, i;
+
+ desc = snewn(W*H+1, char);
+ p = desc;
+ run = 0;
+ for (i = 0; i <= W*H; i++) {
+ int n = (i < W*H ? clues[i] : -2);
+
+ if (n == -1)
+ run++;
+ else {
+ if (run) {
+ while (run > 0) {
+ int c = 'a' - 1 + run;
+ if (run > 26)
+ c = 'z';
+ *p++ = c;
+ run -= c - ('a' - 1);
+ }
+ }
+ if (n >= 0)
+ *p++ = '0' + n;
+ run = 0;
+ }
+ }
+ assert(p - desc <= W*H);
+ *p++ = '\0';
+ desc = sresize(desc, p - desc, char);
+ }
+
+ /*
+ * Encode the solution as an aux_info.
+ */
+ {
+ char *auxbuf;
+ *aux = auxbuf = snewn(w*h+1, char);
+ for (i = 0; i < w*h; i++)
+ auxbuf[i] = soln[i] < 0 ? '\\' : '/';
+ auxbuf[w*h] = '\0';
+ }
+
+ free_scratch(sc);
+ sfree(clueindices);
+ sfree(clues);
+ sfree(tmpsoln);
+ sfree(soln);
+
+ return desc;
+}
+
+static char *validate_desc(game_params *params, char *desc)
+{
+ int w = params->w, h = params->h, W = w+1, H = h+1;
+ int area = W*H;
+ int squares = 0;
+
+ while (*desc) {
+ int n = *desc++;
+ if (n >= 'a' && n <= 'z') {
+ squares += n - 'a' + 1;
+ } else if (n >= '0' && n <= '4') {
+ squares++;
+ } else
+ return "Invalid character in game description";
+ }
+
+ if (squares < area)
+ return "Not enough data to fill grid";
+
+ if (squares > area)
+ return "Too much data to fit in grid";
+
+ return NULL;
+}
+
+static game_state *new_game(midend_data *me, game_params *params, char *desc)
+{
+ int w = params->w, h = params->h, W = w+1, H = h+1;
+ game_state *state = snew(game_state);
+ int area = W*H;
+ int squares = 0;
+
+ state->p = *params;
+ state->soln = snewn(w*h, signed char);
+ memset(state->soln, 0, w*h);
+ state->completed = state->used_solve = FALSE;
+
+ state->clues = snew(game_clues);
+ state->clues->w = w;
+ state->clues->h = h;
+ state->clues->clues = snewn(W*H, signed char);
+ state->clues->refcount = 1;
+ state->clues->dsf = snewn(W*H, int);
+ memset(state->clues->clues, -1, W*H);
+ while (*desc) {
+ int n = *desc++;
+ if (n >= 'a' && n <= 'z') {
+ squares += n - 'a' + 1;
+ } else if (n >= '0' && n <= '4') {
+ state->clues->clues[squares++] = n - '0';
+ } else
+ assert(!"can't get here");
+ }
+ assert(squares == area);
+
+ return state;
+}
+
+static game_state *dup_game(game_state *state)
+{
+ int w = state->p.w, h = state->p.h;
+ game_state *ret = snew(game_state);
+
+ ret->p = state->p;
+ ret->clues = state->clues;
+ ret->clues->refcount++;
+ ret->completed = state->completed;
+ ret->used_solve = state->used_solve;
+
+ ret->soln = snewn(w*h, signed char);
+ memcpy(ret->soln, state->soln, w*h);
+
+ return ret;
+}
+
+static void free_game(game_state *state)
+{
+ sfree(state);
+}
+
+static int check_completion(game_state *state)
+{
+ int w = state->p.w, h = state->p.h, W = w+1, H = h+1;
+ int i, x, y;
+
+ /*
+ * Establish a disjoint set forest for tracking connectedness
+ * between grid points. Use the dsf scratch space in the shared
+ * clues structure, to avoid mallocing too often.
+ */
+ for (i = 0; i < W*H; i++)
+ state->clues->dsf[i] = i; /* initially all distinct */
+
+ /*
+ * Now go through the grid checking connectedness. While we're
+ * here, also check that everything is filled in.
+ */
+ for (y = 0; y < h; y++)
+ for (x = 0; x < w; x++) {
+ int i1, i2;
+
+ if (state->soln[y*w+x] == 0)
+ return FALSE;
+ if (state->soln[y*w+x] < 0) {
+ i1 = y*W+x;
+ i2 = (y+1)*W+(x+1);
+ } else {
+ i1 = (y+1)*W+x;
+ i2 = y*W+(x+1);
+ }
+
+ /*
+ * Our edge connects i1 with i2. If they're already
+ * connected, return failure. Otherwise, link them.
+ */
+ if (dsf_canonify(state->clues->dsf, i1) ==
+ dsf_canonify(state->clues->dsf, i2))
+ return FALSE;
+ else
+ dsf_merge(state->clues->dsf, i1, i2);
+ }
+
+ /*
+ * The grid is _a_ valid grid; let's see if it matches the
+ * clues.
+ */
+ for (y = 0; y < H; y++)
+ for (x = 0; x < W; x++) {
+ int v, c;
+
+ if ((c = state->clues->clues[y*W+x]) < 0)
+ continue;
+
+ v = 0;
+
+ if (x > 0 && y > 0 && state->soln[(y-1)*w+(x-1)] == -1) v++;
+ if (x > 0 && y < h && state->soln[y*w+(x-1)] == +1) v++;
+ if (x < w && y > 0 && state->soln[(y-1)*w+x] == +1) v++;
+ if (x < w && y < h && state->soln[y*w+x] == -1) v++;
+
+ if (c != v)
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+static char *solve_game(game_state *state, game_state *currstate,
+ char *aux, char **error)
+{
+ int w = state->p.w, h = state->p.h;
+ signed char *soln;
+ int bs, ret;
+ int free_soln = FALSE;
+ char *move, buf[80];
+ int movelen, movesize;
+ int x, y;
+
+ if (aux) {
+ /*
+ * If we already have the solution, save ourselves some
+ * time.
+ */
+ soln = (signed char *)aux;
+ bs = (signed char)'\\';
+ free_soln = FALSE;
+ } else {
+ struct solver_scratch *sc = new_scratch(w, h);
+ soln = snewn(w*h, signed char);
+ bs = -1;
+ ret = slant_solve(w, h, state->clues->clues, soln, sc);
+ free_scratch(sc);
+ if (ret != 1) {
+ sfree(soln);
+ if (ret == 0)
+ return "This puzzle is not self-consistent";
+ else
+ return "Unable to find a unique solution for this puzzle";
+ }
+ free_soln = TRUE;
+ }
+
+ /*
+ * Construct a move string which turns the current state into
+ * the solved state.
+ */
+ movesize = 256;
+ move = snewn(movesize, char);
+ movelen = 0;
+ move[movelen++] = 'S';
+ move[movelen] = '\0';
+ for (y = 0; y < h; y++)
+ for (x = 0; x < w; x++) {
+ int v = (soln[y*w+x] == bs ? -1 : +1);
+ if (state->soln[y*w+x] != v) {
+ int len = sprintf(buf, ";%c%d,%d", v < 0 ? '\\' : '/', x, y);
+ if (movelen + len >= movesize) {
+ movesize = movelen + len + 256;
+ move = sresize(move, movesize, char);
+ }
+ strcpy(move + movelen, buf);
+ movelen += len;
+ }
+ }
+
+ if (free_soln)
+ sfree(soln);
+
+ return move;
+}
+
+static char *game_text_format(game_state *state)
+{
+ int w = state->p.w, h = state->p.h, W = w+1, H = h+1;
+ int x, y, len;
+ char *ret, *p;
+
+ /*
+ * There are h+H rows of w+W columns.
+ */
+ len = (h+H) * (w+W+1) + 1;
+ ret = snewn(len, char);
+ p = ret;
+
+ for (y = 0; y < H; y++) {
+ for (x = 0; x < W; x++) {
+ if (state->clues->clues[y*W+x] >= 0)
+ *p++ = state->clues->clues[y*W+x] + '0';
+ else
+ *p++ = '+';
+ if (x < w)
+ *p++ = '-';
+ }
+ *p++ = '\n';
+ if (y < h) {
+ for (x = 0; x < W; x++) {
+ *p++ = '|';
+ if (x < w) {
+ if (state->soln[y*w+x] != 0)
+ *p++ = (state->soln[y*w+x] < 0 ? '\\' : '/');
+ else
+ *p++ = ' ';
+ }
+ }
+ *p++ = '\n';
+ }
+ }
+ *p++ = '\0';
+
+ assert(p - ret == len);
+ return ret;
+}
+
+static game_ui *new_ui(game_state *state)
+{
+ return NULL;
+}
+
+static void free_ui(game_ui *ui)
+{
+}
+
+static char *encode_ui(game_ui *ui)
+{
+ return NULL;
+}
+
+static void decode_ui(game_ui *ui, char *encoding)
+{
+}
+
+static void game_changed_state(game_ui *ui, game_state *oldstate,
+ game_state *newstate)
+{
+}
+
+#define PREFERRED_TILESIZE 32
+#define TILESIZE (ds->tilesize)
+#define BORDER TILESIZE
+#define CLUE_RADIUS (TILESIZE / 3)
+#define CLUE_TEXTSIZE (TILESIZE / 2)
+#define COORD(x) ( (x) * TILESIZE + BORDER )
+#define FROMCOORD(x) ( ((x) - BORDER + TILESIZE) / TILESIZE - 1 )
+
+#define FLASH_TIME 0.30F
+
+/*
+ * Bit fields in the `grid' and `todraw' elements of the drawstate.
+ */
+#define BACKSLASH 0x0001
+#define FORWSLASH 0x0002
+#define L_T 0x0004
+#define L_B 0x0008
+#define T_L 0x0010
+#define T_R 0x0020
+#define R_T 0x0040
+#define R_B 0x0080
+#define B_L 0x0100
+#define B_R 0x0200
+#define C_TL 0x0400
+#define C_TR 0x0800
+#define C_BL 0x1000
+#define C_BR 0x2000
+#define FLASH 0x4000
+
+struct game_drawstate {
+ int tilesize;
+ int started;
+ int *grid;
+ int *todraw;
+};
+
+static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds,
+ int x, int y, int button)
+{
+ int w = state->p.w, h = state->p.h;
+
+ if (button == LEFT_BUTTON || button == RIGHT_BUTTON) {
+ int v;
+ char buf[80];
+
+ x = FROMCOORD(x);
+ y = FROMCOORD(y);
+ if (x < 0 || y < 0 || x >= w || y >= h)
+ return NULL;
+
+ if (button == LEFT_BUTTON) {
+ /*
+ * Left-clicking cycles blank -> \ -> / -> blank.
+ */
+ v = state->soln[y*w+x] - 1;
+ if (v == -2)
+ v = +1;
+ } else {
+ /*
+ * Right-clicking cycles blank -> / -> \ -> blank.
+ */
+ v = state->soln[y*w+x] + 1;
+ if (v == +2)
+ v = -1;
+ }
+
+ sprintf(buf, "%c%d,%d", v==-1 ? '\\' : v==+1 ? '/' : 'C', x, y);
+ return dupstr(buf);
+ }
+
+ return NULL;
+}
+
+static game_state *execute_move(game_state *state, char *move)
+{
+ int w = state->p.w, h = state->p.h;
+ char c;
+ int x, y, n;
+ game_state *ret = dup_game(state);
+
+ while (*move) {
+ c = *move;
+ if (c == 'S') {
+ ret->used_solve = TRUE;
+ move++;
+ } else if (c == '\\' || c == '/' || c == 'C') {
+ move++;
+ if (sscanf(move, "%d,%d%n", &x, &y, &n) != 2 ||
+ x < 0 || y < 0 || x >= w || y >= h) {
+ free_game(ret);
+ return NULL;
+ }
+ ret->soln[y*w+x] = (c == '\\' ? -1 : c == '/' ? +1 : 0);
+ move += n;
+ } else {
+ free_game(ret);
+ return NULL;
+ }
+ if (*move == ';')
+ move++;
+ else if (*move) {
+ free_game(ret);
+ return NULL;
+ }
+ }
+
+ if (!ret->completed)
+ ret->completed = check_completion(ret);
+
+ return ret;
+}
+
+/* ----------------------------------------------------------------------
+ * Drawing routines.
+ */
+
+static void game_compute_size(game_params *params, int tilesize,
+ int *x, int *y)
+{
+ /* fool the macros */
+ struct dummy { int tilesize; } dummy = { tilesize }, *ds = &dummy;
+
+ *x = 2 * BORDER + params->w * TILESIZE + 1;
+ *y = 2 * BORDER + params->h * TILESIZE + 1;
+}
+
+static void game_set_size(game_drawstate *ds, game_params *params,
+ int tilesize)
+{
+ ds->tilesize = tilesize;
+}
+
+static 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] = ret[COL_BACKGROUND * 3 + 0] * 0.7F;
+ ret[COL_GRID * 3 + 1] = ret[COL_BACKGROUND * 3 + 1] * 0.7F;
+ ret[COL_GRID * 3 + 2] = ret[COL_BACKGROUND * 3 + 2] * 0.7F;
+
+ ret[COL_INK * 3 + 0] = 0.0F;
+ ret[COL_INK * 3 + 1] = 0.0F;
+ ret[COL_INK * 3 + 2] = 0.0F;
+
+ *ncolours = NCOLOURS;
+ return ret;
+}
+
+static game_drawstate *game_new_drawstate(game_state *state)
+{
+ int w = state->p.w, h = state->p.h;
+ int i;
+ struct game_drawstate *ds = snew(struct game_drawstate);
+
+ ds->tilesize = 0;
+ ds->started = FALSE;
+ ds->grid = snewn(w*h, int);
+ ds->todraw = snewn(w*h, int);
+ for (i = 0; i < w*h; i++)
+ ds->grid[i] = ds->todraw[i] = -1;
+
+ return ds;
+}
+
+static void game_free_drawstate(game_drawstate *ds)
+{
+ sfree(ds->grid);
+ sfree(ds);
+}
+
+static void draw_clue(frontend *fe, game_drawstate *ds,
+ int x, int y, int v)
+{
+ char p[2];
+
+ if (v < 0)
+ return;
+
+ p[0] = v + '0';
+ p[1] = '\0';
+ draw_circle(fe, COORD(x), COORD(y), CLUE_RADIUS,
+ COL_BACKGROUND, COL_INK);
+ draw_text(fe, COORD(x), COORD(y), FONT_VARIABLE,
+ CLUE_TEXTSIZE, ALIGN_VCENTRE|ALIGN_HCENTRE,
+ COL_INK, p);
+}
+
+static void draw_tile(frontend *fe, game_drawstate *ds, game_clues *clues,
+ int x, int y, int v)
+{
+ int w = clues->w /*, h = clues->h*/, W = w+1 /*, H = h+1 */;
+ int xx, yy;
+
+ clip(fe, COORD(x), COORD(y), TILESIZE+1, TILESIZE+1);
+
+ draw_rect(fe, COORD(x), COORD(y), TILESIZE, TILESIZE,
+ (v & FLASH) ? COL_GRID : COL_BACKGROUND);
+
+ /*
+ * Draw the grid lines.
+ */
+ draw_line(fe, COORD(x), COORD(y), COORD(x+1), COORD(y), COL_GRID);
+ draw_line(fe, COORD(x), COORD(y+1), COORD(x+1), COORD(y+1), COL_GRID);
+ draw_line(fe, COORD(x), COORD(y), COORD(x), COORD(y+1), COL_GRID);
+ draw_line(fe, COORD(x+1), COORD(y), COORD(x+1), COORD(y+1), COL_GRID);
+
+ /*
+ * Draw the slash.
+ */
+ if (v & BACKSLASH) {
+ draw_line(fe, COORD(x), COORD(y), COORD(x+1), COORD(y+1), COL_INK);
+ draw_line(fe, COORD(x)+1, COORD(y), COORD(x+1), COORD(y+1)-1,
+ COL_INK);
+ draw_line(fe, COORD(x), COORD(y)+1, COORD(x+1)-1, COORD(y+1),
+ COL_INK);
+ } else if (v & FORWSLASH) {
+ draw_line(fe, COORD(x+1), COORD(y), COORD(x), COORD(y+1), COL_INK);
+ draw_line(fe, COORD(x+1)-1, COORD(y), COORD(x), COORD(y+1)-1,
+ COL_INK);
+ draw_line(fe, COORD(x+1), COORD(y)+1, COORD(x)+1, COORD(y+1),
+ COL_INK);
+ }
+
+ /*
+ * Draw dots on the grid corners that appear if a slash is in a
+ * neighbouring cell.
+ */
+ if (v & L_T)
+ draw_rect(fe, COORD(x), COORD(y)+1, 1, 1, COL_INK);
+ if (v & L_B)
+ draw_rect(fe, COORD(x), COORD(y+1)-1, 1, 1, COL_INK);
+ if (v & R_T)
+ draw_rect(fe, COORD(x+1), COORD(y)+1, 1, 1, COL_INK);
+ if (v & R_B)
+ draw_rect(fe, COORD(x+1), COORD(y+1)-1, 1, 1, COL_INK);
+ if (v & T_L)
+ draw_rect(fe, COORD(x)+1, COORD(y), 1, 1, COL_INK);
+ if (v & T_R)
+ draw_rect(fe, COORD(x+1)-1, COORD(y), 1, 1, COL_INK);
+ if (v & B_L)
+ draw_rect(fe, COORD(x)+1, COORD(y+1), 1, 1, COL_INK);
+ if (v & B_R)
+ draw_rect(fe, COORD(x+1)-1, COORD(y+1), 1, 1, COL_INK);
+ if (v & C_TL)
+ draw_rect(fe, COORD(x), COORD(y), 1, 1, COL_INK);
+ if (v & C_TR)
+ draw_rect(fe, COORD(x+1), COORD(y), 1, 1, COL_INK);
+ if (v & C_BL)
+ draw_rect(fe, COORD(x), COORD(y+1), 1, 1, COL_INK);
+ if (v & C_BR)
+ draw_rect(fe, COORD(x+1), COORD(y+1), 1, 1, COL_INK);
+
+ /*
+ * And finally the clues at the corners.
+ */
+ for (xx = x; xx <= x+1; xx++)
+ for (yy = y; yy <= y+1; yy++)
+ draw_clue(fe, ds, xx, yy, clues->clues[yy*W+xx]);
+
+ unclip(fe);
+ draw_update(fe, COORD(x), COORD(y), TILESIZE+1, TILESIZE+1);
+}
+
+static void game_redraw(frontend *fe, game_drawstate *ds, game_state *oldstate,
+ game_state *state, int dir, game_ui *ui,
+ float animtime, float flashtime)
+{
+ int w = state->p.w, h = state->p.h, W = w+1 /*, H = h+1 */;
+ int x, y;
+ int flashing;
+
+ if (flashtime > 0)
+ flashing = (int)(flashtime * 3 / FLASH_TIME) != 1;
+ else
+ flashing = FALSE;
+
+ if (!ds->started) {
+ int ww, wh;
+ game_compute_size(&state->p, TILESIZE, &ww, &wh);
+ draw_rect(fe, 0, 0, ww, wh, COL_BACKGROUND);
+ draw_update(fe, 0, 0, ww, wh);
+
+ /*
+ * Draw any clues on the very edges (since normal tile
+ * redraw won't draw the bits outside the grid boundary).
+ */
+ for (y = 0; y < h; y++) {
+ draw_clue(fe, ds, 0, y, state->clues->clues[y*W+0]);
+ draw_clue(fe, ds, w, y, state->clues->clues[y*W+w]);
+ }
+ for (x = 0; x < w; x++) {
+ draw_clue(fe, ds, x, 0, state->clues->clues[0*W+x]);
+ draw_clue(fe, ds, x, h, state->clues->clues[h*W+x]);
+ }
+
+ ds->started = TRUE;
+ }
+
+ /*
+ * Loop over the grid and work out where all the slashes are.
+ * We need to do this because a slash in one square affects the
+ * drawing of the next one along.
+ */
+ for (y = 0; y < h; y++)
+ for (x = 0; x < w; x++)
+ ds->todraw[y*w+x] = flashing ? FLASH : 0;
+
+ for (y = 0; y < h; y++) {
+ for (x = 0; x < w; x++) {
+ if (state->soln[y*w+x] < 0) {
+ ds->todraw[y*w+x] |= BACKSLASH;
+ if (x > 0)
+ ds->todraw[y*w+(x-1)] |= R_T | C_TR;
+ if (x+1 < w)
+ ds->todraw[y*w+(x+1)] |= L_B | C_BL;
+ if (y > 0)
+ ds->todraw[(y-1)*w+x] |= B_L | C_BL;
+ if (y+1 < h)
+ ds->todraw[(y+1)*w+x] |= T_R | C_TR;
+ if (x > 0 && y > 0)
+ ds->todraw[(y-1)*w+(x-1)] |= C_BR;
+ if (x+1 < w && y+1 < h)
+ ds->todraw[(y+1)*w+(x+1)] |= C_TL;
+ } else if (state->soln[y*w+x] > 0) {
+ ds->todraw[y*w+x] |= FORWSLASH;
+ if (x > 0)
+ ds->todraw[y*w+(x-1)] |= R_B | C_BR;
+ if (x+1 < w)
+ ds->todraw[y*w+(x+1)] |= L_T | C_TL;
+ if (y > 0)
+ ds->todraw[(y-1)*w+x] |= B_R | C_BR;
+ if (y+1 < h)
+ ds->todraw[(y+1)*w+x] |= T_L | C_TL;
+ if (x > 0 && y+1 < h)
+ ds->todraw[(y+1)*w+(x-1)] |= C_TR;
+ if (x+1 < w && y > 0)
+ ds->todraw[(y-1)*w+(x+1)] |= C_BL;
+ }
+ }
+ }
+
+ /*
+ * Now go through and draw the grid squares.
+ */
+ for (y = 0; y < h; y++) {
+ for (x = 0; x < w; x++) {
+ if (ds->todraw[y*w+x] != ds->grid[y*w+x]) {
+ draw_tile(fe, ds, state->clues, x, y, ds->todraw[y*w+x]);
+ ds->grid[y*w+x] = ds->todraw[y*w+x];
+ }
+ }
+ }
+}
+
+static float game_anim_length(game_state *oldstate, game_state *newstate,
+ int dir, game_ui *ui)
+{
+ return 0.0F;
+}
+
+static float game_flash_length(game_state *oldstate, game_state *newstate,
+ int dir, game_ui *ui)
+{
+ if (!oldstate->completed && newstate->completed &&
+ !oldstate->used_solve && !newstate->used_solve)
+ return FLASH_TIME;
+
+ return 0.0F;
+}
+
+static int game_wants_statusbar(void)
+{
+ return FALSE;
+}
+
+static int game_timing_state(game_state *state, game_ui *ui)
+{
+ return TRUE;
+}
+
+#ifdef COMBINED
+#define thegame slant
+#endif
+
+const struct game thegame = {
+ "Slant", "games.slant",
+ default_params,
+ game_fetch_preset,
+ decode_params,
+ encode_params,
+ free_params,
+ dup_params,
+ TRUE, game_configure, custom_params,
+ validate_params,
+ new_game_desc,
+ validate_desc,
+ new_game,
+ dup_game,
+ free_game,
+ TRUE, solve_game,
+ TRUE, game_text_format,
+ new_ui,
+ free_ui,
+ encode_ui,
+ decode_ui,
+ game_changed_state,
+ interpret_move,
+ execute_move,
+ PREFERRED_TILESIZE, game_compute_size, game_set_size,
+ game_colours,
+ game_new_drawstate,
+ game_free_drawstate,
+ game_redraw,
+ game_anim_length,
+ game_flash_length,
+ game_wants_statusbar,
+ FALSE, game_timing_state,
+ 0, /* mouse_priorities */
+};
~mdw / sgt / puzzles / commitdiff