shithub: puzzles

Download patch

ref: 67ddba7a15573643666f0f4128d43d0095b80da0
parent: 15a4fbd1cdc2cc092bafe85b8ddd8b392bdbda7d
author: Simon Tatham <anakin@pobox.com>
date: Sat Sep 8 06:48:05 EDT 2012

New puzzle! Contributed by Steffen Bauer, an implementation of
'Haunted Mirror Maze', a game involving placing ghosts, zombies and
vampires in a grid so that the right numbers of them are visible along
sight-lines reflected through multiple mirrors.

[originally from svn r9652]

--- a/LICENCE
+++ b/LICENCE
@@ -1,8 +1,8 @@
 This software is copyright (c) 2004-2012 Simon Tatham.
 
 Portions copyright Richard Boulton, James Harvey, Mike Pinna, Jonas
-K�lker, Dariusz Olszewski, Michael Schierl, Lambros Lambrou and
-Bernd Schmidt.
+K�lker, Dariusz Olszewski, Michael Schierl, Lambros Lambrou, Bernd
+Schmidt and Steffen Bauer.
 
 Permission is hereby granted, free of charge, to any person
 obtaining a copy of this software and associated documentation files
--- a/icons/Makefile
+++ b/icons/Makefile
@@ -1,9 +1,10 @@
 # Makefile for Puzzles icons.
 
-PUZZLES = blackbox bridges cube dominosa fifteen filling flip galaxies guess \
-	  inertia keen lightup loopy magnets map mines net netslide pattern \
-	  pearl pegs range rect samegame signpost singles sixteen slant solo \
-	  tents towers twiddle unequal untangle
+PUZZLES = blackbox bridges cube dominosa fifteen filling flip galaxies	\
+	  guess inertia keen lightup loopy magnets map mines net	\
+	  netslide pattern pearl pegs range rect samegame signpost	\
+	  singles sixteen slant solo tents towers twiddle undead	\
+	  unequal untangle
 
 BASE = $(patsubst %,%-base.png,$(PUZZLES))
 WEB = $(patsubst %,%-web.png,$(PUZZLES))
@@ -81,6 +82,7 @@
 tents-ibase.png : override CROP=320x320 165x165+142+0
 towers-ibase.png : override CROP=300x300 102x102+151+6
 twiddle-ibase.png : override CROP=192x192 102x102+69+21
+undead-ibase.png : override CROP=448x512 192x192+32+96
 unequal-ibase.png : override CROP=208x208 104x104+104+104
 untangle-ibase.png : override CROP=320x320 164x164+3+116
 $(IBASE): %-ibase.png: %-base.png
--- /dev/null
+++ b/icons/undead.sav
@@ -1,0 +1,14 @@
+SAVEFILE:41:Simon Tatham's Portable Puzzle Collection
+VERSION :1:1
+GAME    :6:Undead
+PARAMS  :6:4x4de2
+CPARAMS :6:4x4de2
+DESC    :48:5,2,2,aRLgLLaLRL,2,0,1,2,1,1,2,5,0,0,0,2,1,3,1,1
+NSTATES :1:7
+STATEPOS:1:7
+MOVE    :2:G0
+MOVE    :2:V0
+MOVE    :2:G2
+MOVE    :2:G3
+MOVE    :2:V3
+MOVE    :2:Z3
--- a/puzzles.but
+++ b/puzzles.but
@@ -2971,6 +2971,79 @@
 These parameters are available from the \q{Custom...} option on the
 \q{Type} menu.
 
+\C{undead} \i{Undead}
+
+\cfg{winhelp-topic}{games.undead}
+
+You are given a grid of squares, some of which contain diagonal
+mirrors. Every square which is not a mirror must be filled with one of
+three types of undead monster: a ghost, a vampire, or a zombie.
+
+Vampires can be seen directly, but are invisible when reflected in
+mirrors. Ghosts are the opposite way round: they can be seen in
+mirrors, but are invisible when looked at directly. Zombies are
+visible by any means.
+
+Around the edge of the grid are written numbers, which indicate how
+many monsters can be seen if you look into the grid along a row or
+column starting from that position. (The diagonal mirrors are
+reflective on both sides.) You are also told the total number of each
+type of monster in the grid.
+
+This puzzle type was invented by David Millar, under the name
+\q{Haunted Mirror Maze}. See \k{janko-undead} for more details.
+
+Undead was contributed to this collection by Steffen Bauer.
+
+\B{janko-undead}
+\W{http://www.janko.at/Raetsel/Spukschloss/index.htm}
+
+\H{undead-controls} \I{controls, for Undead}Undead controls
+
+Undead has a similar control system to Solo, Unequal and Keen.
+
+To play Undead, click the mouse in any empty square and then type a
+letter on the keyboard indicating the type of monster: \q{G} for a
+ghost, \q{V} for a vampire, or \q{Z} for a zombie. If you make a
+mistake, click the mouse in the incorrect square and press Space to
+clear it again (or use the Undo feature).
+
+If you \e{right}-click in a square and then type a letter, the
+corresponding monster will be shown in reduced size in that square, as
+a \q{pencil mark}. You can have pencil marks for multiple monsters in
+the same square. A square containing a full-size monster cannot also
+contain pencil marks.
+
+The game pays no attention to pencil marks, so exactly what you use
+them for is up to you: you can use them as reminders that a particular
+square needs to be re-examined once you know more about a particular
+monster, or you can use them as lists of the possible monster in a
+given square, or anything else you feel like.
+
+To erase a single pencil mark, right-click in the square and type
+the same letter again.
+
+All pencil marks in a square are erased when you left-click and type a
+monster letter, or when you left-click and press Space. Right-clicking
+and pressing space will also erase pencil marks.
+
+As for Solo, the cursor keys can be used in conjunction with the digit
+keys to place monsters or pencil marks. Use the cursor keys to move a
+highlight around the grid, and type a monster letter to enter it in
+the highlighted square. Pressing return toggles the highlight into a
+mode in which you can enter or remove pencil marks.
+
+If you prefer plain letters of the alphabet to cute monster pictures,
+you can press A to toggle between showing the monsters as monsters or
+showing them as letters.
+
+(All the actions described in \k{common-actions} are also available.)
+
+\H{undead-parameters} \I{parameters, for Undead}Undead parameters
+
+These parameters are available from the \q{Custom...} option on the
+\q{Type} menu.
+
 \dt \e{Width}, \e{Height}
 
 \dd Size of grid in squares.
@@ -2985,7 +3058,7 @@
 
 Portions copyright Richard Boulton, James Harvey, Mike Pinna, Jonas
 K\u00F6{oe}lker, Dariusz Olszewski, Michael Schierl, Lambros
-Lambrou and Bernd Schmidt.
+Lambrou, Bernd Schmidt and Steffen Bauer.
 
 Permission is hereby granted, free of charge, to any person
 obtaining a copy of this software and associated documentation files
--- /dev/null
+++ b/undead.R
@@ -1,0 +1,18 @@
+# -*- makefile -*-
+
+undead : [X] GTK COMMON undead undead-icon|no-icon
+undead : [G] WINDOWS COMMON undead undead.res|noicon.res
+
+ALL += undead[COMBINED]
+
+!begin gtk
+GAMES += undead
+!end
+
+!begin >list.c
+    A(undead) \
+!end
+
+!begin >wingames.lst
+undead.exe:Undead
+!end
--- /dev/null
+++ b/undead.c
@@ -1,0 +1,2594 @@
+/*
+ * undead: Implementation of Haunted Mirror Mazes
+ *
+ * http://www.janko.at/Raetsel/Spukschloss/index.htm
+ *
+ * Puzzle definition is the total number of each monster type, the
+ * grid definition, and the list of sightings (clockwise, starting
+ * from top left corner)
+ *
+ * Example: (Janko puzzle No. 1,
+ * http://www.janko.at/Raetsel/Spukschloss/001.a.htm )
+ *
+ *   Ghosts: 0 Vampires: 2 Zombies: 6
+ *
+ *     2 1 1 1
+ *   1 \ \ . / 2
+ *   0 \ . / . 2
+ *   0 / . / . 2
+ *   3 . . . \ 2
+ *     3 3 2 2
+ *
+ *  would be encoded into: 
+ *     4x4:0,2,6,LLaRLaRaRaRdL,2,1,1,1,2,2,2,2,2,2,3,3,3,0,0,1
+ *
+ *  Additionally, the game description can contain monsters fixed at a
+ *  certain grid position. The internal generator does not (yet) use
+ *  this feature, but this is needed to enter puzzles like Janko No.
+ *  14, which is encoded as:
+ *  8x5:12,12,0,LaRbLaRaLaRLbRaVaVaGRaRaRaLbLaRbRLb,0,2,0,2,2,1,2,1,3,1,0,1,8,4,3,0,0,2,3,2,7,2,1,6,2,1
+ * 
+ */
+
+#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_TEXT,
+    COL_ERROR,
+    COL_HIGHLIGHT,
+    COL_FLASH,
+    COL_GHOST,
+    COL_ZOMBIE,
+    COL_VAMPIRE,
+    NCOLOURS
+};
+
+#define DIFFLIST(A) \
+    A(EASY,Easy,e) \
+    A(NORMAL,Normal,n) \
+    A(TRICKY,Tricky,t)
+#define ENUM(upper,title,lower) DIFF_ ## upper,
+#define TITLE(upper,title,lower) #title,
+#define ENCODE(upper,title,lower) #lower
+#define CONFIG(upper,title,lower) ":" #title
+enum { DIFFLIST(ENUM) DIFFCOUNT };
+static char const *const undead_diffnames[] = { DIFFLIST(TITLE) "(count)" };
+static char const undead_diffchars[] = DIFFLIST(ENCODE);
+#define DIFFCONFIG DIFFLIST(CONFIG)
+
+struct game_params {
+    int w;      /* Grid width */
+    int h;      /* Grid height */
+    int diff;   /* Puzzle difficulty */
+};
+
+static const struct game_params undead_presets[] = {
+    {  4,  4, DIFF_EASY },
+    {  4,  4, DIFF_NORMAL },
+    {  4,  4, DIFF_TRICKY },
+    {  5,  5, DIFF_EASY },
+    {  5,  5, DIFF_NORMAL },
+    {  5,  5, DIFF_TRICKY },
+    {  7,  7, DIFF_EASY },
+    {  7,  7, DIFF_NORMAL }
+};
+
+#define DEFAULT_PRESET 1
+
+static game_params *default_params(void) {
+    game_params *ret = snew(game_params);
+
+    *ret = undead_presets[DEFAULT_PRESET];
+    return ret;
+}
+
+static int game_fetch_preset(int i, char **name, game_params **params) {
+    game_params *ret;
+    char buf[64];
+
+    if (i < 0 || i >= lenof(undead_presets)) return FALSE;
+
+    ret = default_params();
+    *ret = undead_presets[i]; /* struct copy */
+    *params = ret;
+
+    sprintf(buf, "%dx%d %s",
+            undead_presets[i].w, undead_presets[i].h,
+            undead_diffnames[undead_presets[i].diff]);
+    *name = dupstr(buf);
+
+    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 *params, char const *string) {
+    params->w = params->h = atoi(string);
+
+    while (*string && isdigit((unsigned char) *string)) ++string;
+    if (*string == 'x') {
+        string++;
+        params->h = atoi(string);
+        while (*string && isdigit((unsigned char)*string)) string++;
+    }
+
+    params->diff = DIFF_NORMAL;
+    if (*string == 'd') {
+        int i;
+        string++;
+        for (i = 0; i < DIFFCOUNT; i++)
+            if (*string == undead_diffchars[i])
+                params->diff = i;
+        if (*string) string++;
+    }
+
+    return;
+}
+
+static char *encode_params(game_params *params, int full) {
+    char buf[256];
+    sprintf(buf, "%dx%d", params->w, params->h);
+    if (full)
+        sprintf(buf + strlen(buf), "d%c", undead_diffchars[params->diff]);
+    return dupstr(buf);
+}
+
+static config_item *game_configure(game_params *params) {
+    config_item *ret;
+    char buf[64];
+
+    ret = snewn(4, 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 = "Difficulty";
+    ret[2].type = C_CHOICES;
+    ret[2].sval = DIFFCONFIG;
+    ret[2].ival = params->diff;
+
+    ret[3].name = NULL;
+    ret[3].type = C_END;
+    ret[3].sval = NULL;
+    ret[3].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);
+    ret->diff = cfg[2].ival;
+    return ret;
+}
+
+static char *validate_params(game_params *params, int full) {
+    if ((params->w * params->h ) > 54)  return "Grid is too big";
+    if (params->w < 3)                  return "Width must be at least 3";
+    if (params->h < 3)                  return "Height must be at least 3";
+    if (params->diff >= DIFFCOUNT)      return "Unknown difficulty rating";
+    return NULL;
+}
+
+/* --------------------------------------------------------------- */
+/* Game state allocation, deallocation. */
+
+struct path {
+    int length;
+    int *p;
+    int grid_start;
+    int grid_end;
+    int num_monsters;
+    int *mapping;
+    int sightings_start;
+    int sightings_end;
+    int *xy;
+};
+
+struct game_common {
+    int refcount;
+    struct game_params params;
+    int wh;
+    int num_ghosts,num_vampires,num_zombies,num_total;
+    int num_paths;
+    struct path *paths;
+    int *grid;
+    int *xinfo;
+    int *fixed;
+    int solved;
+};
+
+struct game_state {
+    struct game_common *common;
+    int *guess;
+    unsigned char *pencils;
+    unsigned char *cell_errors;
+    unsigned char *hint_errors;
+    unsigned char count_errors[3];
+    int solved;
+    int cheated;
+};
+
+static game_state *new_state(game_params *params) {
+    int i;
+    game_state *state = snew(game_state);
+    state->common = snew(struct game_common);
+
+    state->common->refcount = 1;
+    state->common->params.w = params->w;
+    state->common->params.h = params->h;
+    state->common->params.diff = params->diff;
+
+    state->common->wh = (state->common->params.w +2) * (state->common->params.h +2);
+
+    state->common->num_ghosts = 0;
+    state->common->num_vampires = 0;
+    state->common->num_zombies = 0;
+    state->common->num_total = 0;
+
+    state->common->grid = snewn(state->common->wh, int);
+    state->common->xinfo = snewn(state->common->wh, int);
+    state->common->fixed = NULL;
+    state->common->solved = FALSE;
+
+    state->common->num_paths =
+        state->common->params.w + state->common->params.h;
+    state->common->paths = snewn(state->common->num_paths, struct path);
+
+    for (i=0;i<state->common->num_paths;i++) {
+        state->common->paths[i].length = 0;
+        state->common->paths[i].grid_start = -1;
+        state->common->paths[i].grid_end = -1;
+        state->common->paths[i].num_monsters = 0;
+        state->common->paths[i].sightings_start = 0;
+        state->common->paths[i].sightings_end = 0;
+        state->common->paths[i].p = snewn(state->common->wh,int);
+        state->common->paths[i].xy = snewn(state->common->wh,int);
+        state->common->paths[i].mapping = snewn(state->common->wh,int);
+    }
+
+    state->guess = NULL;
+    state->pencils = NULL;
+
+    state->cell_errors = snewn(state->common->wh, unsigned char);
+    for (i=0;i<state->common->wh;i++)
+        state->cell_errors[i] = FALSE;
+    state->hint_errors = snewn(2*state->common->num_paths, unsigned char);
+    for (i=0;i<2*state->common->num_paths;i++)
+        state->hint_errors[i] = FALSE;
+    for (i=0;i<3;i++)
+        state->count_errors[i] = FALSE;
+
+    state->solved = FALSE;
+    state->cheated = FALSE;
+    
+    return state;
+}
+
+static game_state *dup_game(game_state *state) {
+    game_state *ret = snew(game_state);
+
+    ret->common = state->common;
+    ret->common->refcount++;
+
+    if (state->guess != NULL) {
+        ret->guess = snewn(ret->common->num_total,int);
+        memcpy(ret->guess, state->guess, ret->common->num_total*sizeof(int));
+    }
+    else ret->guess = NULL;
+
+    if (state->pencils != NULL) {
+        ret->pencils = snewn(ret->common->num_total,unsigned char);
+        memcpy(ret->pencils, state->pencils,
+               ret->common->num_total*sizeof(unsigned char));
+    }
+    else ret->pencils = NULL;
+
+    if (state->cell_errors != NULL) {
+        ret->cell_errors = snewn(ret->common->wh,unsigned char);
+        memcpy(ret->cell_errors, state->cell_errors,
+               ret->common->wh*sizeof(unsigned char));
+    }
+    else ret->cell_errors = NULL;
+
+    if (state->hint_errors != NULL) {
+        ret->hint_errors = snewn(2*ret->common->num_paths,unsigned char);
+        memcpy(ret->hint_errors, state->hint_errors,
+               2*ret->common->num_paths*sizeof(unsigned char));
+    }
+    else ret->hint_errors = NULL;
+
+    ret->count_errors[0] = state->count_errors[0];
+    ret->count_errors[1] = state->count_errors[1];
+    ret->count_errors[2] = state->count_errors[2];
+
+    ret->solved = state->solved;
+    ret->cheated = state->cheated;
+    
+    return ret;
+}
+
+static void free_game(game_state *state) {
+    int i;
+
+    state->common->refcount--;
+    if (state->common->refcount == 0) {
+        for (i=0;i<state->common->num_paths;i++) {
+            sfree(state->common->paths[i].mapping);
+            sfree(state->common->paths[i].xy);
+            sfree(state->common->paths[i].p);
+        }
+        sfree(state->common->paths);
+        sfree(state->common->xinfo);
+        sfree(state->common->grid);
+        if (state->common->fixed != NULL) sfree(state->common->fixed);
+        sfree(state->common);
+    }
+    if (state->hint_errors != NULL) sfree(state->hint_errors);
+    if (state->cell_errors != NULL) sfree(state->cell_errors);
+    if (state->pencils != NULL) sfree(state->pencils);
+    if (state->guess != NULL) sfree(state->guess);
+    sfree(state);
+
+    return;
+}
+
+/* --------------------------------------------------------------- */
+/* Puzzle generator */
+
+/* cell states */
+enum {
+    CELL_EMPTY,
+    CELL_MIRROR_L,
+    CELL_MIRROR_R,
+    CELL_GHOST,
+    CELL_VAMPIRE,
+    CELL_ZOMBIE,
+    CELL_UNDEF
+};
+
+/* grid walk directions */
+enum {
+    DIRECTION_NONE,
+    DIRECTION_UP,
+    DIRECTION_RIGHT,
+    DIRECTION_LEFT,
+    DIRECTION_DOWN
+};
+
+int range2grid(int rangeno, int width, int height, int *x, int *y) {
+
+    if (rangeno < 0) {
+        *x = 0; *y = 0; return DIRECTION_NONE;
+    }
+    if (rangeno < width) {
+        *x = rangeno+1; *y = 0; return DIRECTION_DOWN;
+    }
+    rangeno = rangeno - width;
+    if (rangeno < height) {
+        *x = width+1; *y = rangeno+1; return DIRECTION_LEFT;
+    }
+    rangeno = rangeno - height;
+    if (rangeno < width) {
+        *x = width-rangeno; *y = height+1; return DIRECTION_UP;
+    }
+    rangeno = rangeno - width;
+    if (rangeno < height) {
+        *x = 0; *y = height-rangeno; return DIRECTION_RIGHT;
+    }
+    *x = 0; *y = 0;
+    return DIRECTION_NONE;
+}
+
+int grid2range(int x, int y, int w, int h) {
+    if (x>0 && x<w+1 && y>0 && y<h+1)           return -1;
+    if (x<0 || x>w+1 || y<0 || y>h+1)           return -1;
+    if ((x == 0 || x==w+1) && (y==0 || y==h+1)) return -1;
+    if (y==0)                                   return x-1;
+    if (x==(w+1))                               return y-1+w;
+    if (y==(h+1))                               return 2*w + h - x;
+    return 2*(w+h) - y;
+}
+
+void make_paths(game_state *state) {
+    int i;
+    int count = 0;
+
+    for (i=0;i<2*(state->common->params.w + state->common->params.h);i++) {
+        int x,y,dir;
+        int j,k,num_monsters;
+        int found;
+        int c,p; 
+        found = FALSE;
+        /* Check whether inverse path is already in list */
+        for (j=0;j<count;j++) {
+            if (i == state->common->paths[j].grid_end) {
+                found = TRUE;
+                break;
+            }
+        }
+        if (found) continue;
+
+        /* We found a new path through the mirror maze */
+        state->common->paths[count].grid_start = i;     
+        dir = range2grid(i, state->common->params.w,
+                         state->common->params.h,&x,&y);     
+        state->common->paths[count].sightings_start =
+            state->common->grid[x+y*(state->common->params.w +2)];
+        while (TRUE) {
+            int c,r;
+
+            if      (dir == DIRECTION_DOWN)     y++;
+            else if (dir == DIRECTION_LEFT)     x--;
+            else if (dir == DIRECTION_UP)       y--;
+            else if (dir == DIRECTION_RIGHT)    x++;
+            
+            r = grid2range(x, y, state->common->params.w,
+                           state->common->params.h);
+            if (r != -1) {
+                state->common->paths[count].grid_end = r;               
+                state->common->paths[count].sightings_end =
+                    state->common->grid[x+y*(state->common->params.w +2)];
+                break;
+            }
+
+            c = state->common->grid[x+y*(state->common->params.w+2)];
+            state->common->paths[count].xy[state->common->paths[count].length] =
+                x+y*(state->common->params.w+2);
+            if (c == CELL_MIRROR_L) {
+                state->common->paths[count].p[state->common->paths[count].length] = -1;
+                if (dir == DIRECTION_DOWN)          dir = DIRECTION_RIGHT;
+                else if (dir == DIRECTION_LEFT)     dir = DIRECTION_UP;
+                else if (dir == DIRECTION_UP)       dir = DIRECTION_LEFT;
+                else if (dir == DIRECTION_RIGHT)    dir = DIRECTION_DOWN;
+            }
+            else if (c == CELL_MIRROR_R) {
+                state->common->paths[count].p[state->common->paths[count].length] = -1;
+                if (dir == DIRECTION_DOWN)          dir = DIRECTION_LEFT;
+                else if (dir == DIRECTION_LEFT)     dir = DIRECTION_DOWN;
+                else if (dir == DIRECTION_UP)       dir = DIRECTION_RIGHT;
+                else if (dir == DIRECTION_RIGHT)    dir = DIRECTION_UP;
+            }
+            else {
+                state->common->paths[count].p[state->common->paths[count].length] =
+                    state->common->xinfo[x+y*(state->common->params.w+2)];
+            }
+            state->common->paths[count].length++;
+        }
+        /* Count unique monster entries in each path */
+        state->common->paths[count].num_monsters = 0;
+        for (j=0;j<state->common->num_total;j++) {
+            num_monsters = 0;
+            for (k=0;k<state->common->paths[count].length;k++)
+                if (state->common->paths[count].p[k] == j)
+                    num_monsters++;
+            if (num_monsters > 0)
+                state->common->paths[count].num_monsters++;
+        }
+
+        /* Generate mapping vector */
+        c = 0;
+        for (p=0;p<state->common->paths[count].length;p++) {
+            int m;
+            m = state->common->paths[count].p[p];
+            if (m == -1) continue;
+            found = FALSE;
+            for (j=0; j<c; j++)
+                if (state->common->paths[count].mapping[j] == m) found = TRUE;
+            if (!found) state->common->paths[count].mapping[c++] = m;
+        }
+        count++;
+    }
+    return;
+}
+
+struct guess {
+    int length;
+    int *guess;
+    int *possible;
+};
+
+int next_list(struct guess *g, int pos) {
+
+    if (pos == 0) {
+        if ((g->guess[pos] == 1 && g->possible[pos] == 1) || 
+            (g->guess[pos] == 2 && (g->possible[pos] == 3 ||
+                                    g->possible[pos] == 2)) ||
+            g->guess[pos] == 4)
+            return FALSE;
+        if (g->guess[pos] == 1 && (g->possible[pos] == 3 ||
+                                   g->possible[pos] == 7)) {
+            g->guess[pos] = 2; return TRUE;
+        }
+        if (g->guess[pos] == 1 && g->possible[pos] == 5) {
+            g->guess[pos] = 4; return TRUE;
+        }
+        if (g->guess[pos] == 2 && (g->possible[pos] == 6 || g->possible[pos] == 7)) {
+            g->guess[pos] = 4; return TRUE;
+        }
+    }
+
+    if (g->guess[pos] == 1) {
+        if (g->possible[pos] == 1) {
+            return next_list(g,pos-1);
+        }
+        if (g->possible[pos] == 3 || g->possible[pos] == 7) {
+            g->guess[pos] = 2; return TRUE;
+        }
+        if (g->possible[pos] == 5) {
+            g->guess[pos] = 4; return TRUE;
+        }
+    }
+
+    if (g->guess[pos] == 2) {
+        if (g->possible[pos] == 2) {
+            return next_list(g,pos-1);
+        }
+        if (g->possible[pos] == 3) {
+            g->guess[pos] = 1; return next_list(g,pos-1);
+        }
+        if (g->possible[pos] == 6 || g->possible[pos] == 7) {
+            g->guess[pos] = 4; return TRUE;
+        }
+    }
+
+    if (g->guess[pos] == 4) {
+        if (g->possible[pos] == 5 || g->possible[pos] == 7) {
+            g->guess[pos] = 1; return next_list(g,pos-1);
+        }
+        if (g->possible[pos] == 6) {
+            g->guess[pos] = 2; return next_list(g,pos-1);
+        }
+        if (g->possible[pos] == 4) {
+            return next_list(g,pos-1);
+        }
+    }
+    return FALSE;
+}
+
+void get_unique(game_state *state, int counter, random_state *rs) {
+
+    int p,i,c,count_uniques;
+    struct guess path_guess;
+    
+    struct entry {
+        struct entry *link;
+        int *guess;
+        int start_view;
+        int end_view;
+    };
+
+    struct {
+        struct entry *head;
+        struct entry *node;
+    } views, single_views, loop_views, test_views;
+
+    struct entry test_entry;
+    
+    path_guess.length = state->common->paths[counter].num_monsters;
+    path_guess.guess = snewn(path_guess.length,int);
+    path_guess.possible = snewn(path_guess.length,int);
+    for (i=0;i<path_guess.length;i++) 
+        path_guess.guess[i] = path_guess.possible[i] = 0;
+
+    for (p=0;p<path_guess.length;p++) {
+        path_guess.possible[p] =
+            state->guess[state->common->paths[counter].mapping[p]];
+        switch (path_guess.possible[p]) {
+            case 1: path_guess.guess[p] = 1; break;
+            case 2: path_guess.guess[p] = 2; break;
+            case 3: path_guess.guess[p] = 1; break;
+            case 4: path_guess.guess[p] = 4; break;
+            case 5: path_guess.guess[p] = 1; break;
+            case 6: path_guess.guess[p] = 2; break;
+            case 7: path_guess.guess[p] = 1; break;
+        }
+    }
+
+    views.head = NULL;
+    views.node = NULL;
+    
+    do {
+        int mirror;
+        
+        views.node = snewn(1,struct entry);
+        views.node->link = views.head;
+        views.node->guess = snewn(path_guess.length,int);
+        views.head = views.node;
+        views.node->start_view = 0;
+        views.node->end_view = 0;
+        memcpy(views.node->guess, path_guess.guess,
+               path_guess.length*sizeof(int));
+
+        mirror = FALSE;
+        for (p=0;p<state->common->paths[counter].length;p++) {
+            if (state->common->paths[counter].p[p] == -1) mirror = TRUE;
+            else {
+                for (i=0;i<path_guess.length;i++) {
+                    if (state->common->paths[counter].p[p] ==
+                        state->common->paths[counter].mapping[i]) {
+                        if (path_guess.guess[i] == 1 && mirror == TRUE)
+                            views.node->start_view++;
+                        if (path_guess.guess[i] == 2 && mirror == FALSE)
+                            views.node->start_view++;
+                        if (path_guess.guess[i] == 4)
+                            views.node->start_view++;
+                        break;
+                    }
+                }
+            }
+        }
+        mirror = FALSE;
+        for (p=state->common->paths[counter].length-1;p>=0;p--) {
+            if (state->common->paths[counter].p[p] == -1) mirror = TRUE;
+            else {
+                for (i=0;i<path_guess.length;i++) {
+                    if (state->common->paths[counter].p[p] ==
+                        state->common->paths[counter].mapping[i]) {
+                        if (path_guess.guess[i] == 1 && mirror == TRUE)
+                            views.node->end_view++;
+                        if (path_guess.guess[i] == 2 && mirror == FALSE)
+                            views.node->end_view++;
+                        if (path_guess.guess[i] == 4)
+                            views.node->end_view++;
+                        break;
+                    }
+                }
+            }
+        }
+    } while (next_list(&path_guess, path_guess.length-1));
+
+    /*  extract single entries from view list */
+
+    test_views.head = views.head;
+    test_views.node = views.node;
+    
+    test_entry.guess = snewn(path_guess.length,int);
+
+    single_views.head = NULL;
+    single_views.node = NULL;
+
+    count_uniques = 0;
+    while (test_views.head != NULL) {
+        test_views.node = test_views.head;
+        test_views.head = test_views.head->link;
+        c = 0;
+        loop_views.head = views.head;
+        loop_views.node = views.node;
+        while (loop_views.head != NULL) {
+            loop_views.node = loop_views.head;
+            loop_views.head = loop_views.head->link;
+            if (test_views.node->start_view == loop_views.node->start_view &&
+                test_views.node->end_view == loop_views.node->end_view)
+                c++;
+        }
+        if (c == 1) {
+            single_views.node = snewn(1,struct entry);
+            single_views.node->link = single_views.head;
+            single_views.node->guess = snewn(path_guess.length,int);
+            single_views.head = single_views.node;
+            single_views.node->start_view = test_views.node->start_view;
+            single_views.node->end_view = test_views.node->end_view;
+            memcpy(single_views.node->guess, test_views.node->guess,
+                   path_guess.length*sizeof(int));
+            count_uniques++;
+        }
+    }
+
+    if (count_uniques > 0) {
+        test_entry.start_view = 0;
+        test_entry.end_view = 0;
+        /* Choose one unique guess per random */
+        /* While we are busy with looping through single_views, we
+         * conveniently free the linked list single_view */
+        c = random_upto(rs,count_uniques);
+        while(single_views.head != NULL) {
+            single_views.node = single_views.head;
+            single_views.head = single_views.head->link;
+            if (c-- == 0) {
+                memcpy(test_entry.guess, single_views.node->guess,
+                       path_guess.length*sizeof(int));
+                test_entry.start_view = single_views.node->start_view;
+                test_entry.end_view = single_views.node->end_view;
+            }
+            sfree(single_views.node->guess);
+            sfree(single_views.node);
+        }
+        
+        /* Modify state_guess according to path_guess.mapping */
+        for (i=0;i<path_guess.length;i++)
+            state->guess[state->common->paths[counter].mapping[i]] =
+                test_entry.guess[i];
+    }
+
+    sfree(test_entry.guess);
+
+    while (views.head != NULL) {
+        views.node = views.head;
+        views.head = views.head->link;
+        sfree(views.node->guess);
+        sfree(views.node);
+    }
+
+    sfree(path_guess.possible);
+    sfree(path_guess.guess);
+
+    return;
+}
+
+int count_monsters(game_state *state,
+                   int *cGhost, int *cVampire, int *cZombie) {
+    int cNone;
+    int i;
+
+    *cGhost = *cVampire = *cZombie = cNone = 0;
+
+    for (i=0;i<state->common->num_total;i++) {
+        if (state->guess[i] == 1) (*cGhost)++;
+        else if (state->guess[i] == 2) (*cVampire)++;
+        else if (state->guess[i] == 4) (*cZombie)++;
+        else cNone++;
+    }
+
+    return cNone;
+}
+
+int check_numbers(game_state *state, int *guess) {
+    int valid;
+    int i;
+    int count_ghosts, count_vampires, count_zombies;
+
+    count_ghosts = count_vampires = count_zombies = 0;  
+    for (i=0;i<state->common->num_total;i++) {
+        if (guess[i] == 1) count_ghosts++;
+        if (guess[i] == 2) count_vampires++;
+        if (guess[i] == 4) count_zombies++;
+    }
+
+    valid = TRUE;
+
+    if (count_ghosts   > state->common->num_ghosts)   valid = FALSE; 
+    if (count_vampires > state->common->num_vampires) valid = FALSE; 
+    if (count_zombies > state->common->num_zombies)   valid = FALSE; 
+
+    return valid;
+}
+
+int check_solution(int *g, struct path path) {
+    int i;
+    int mirror;
+    int count;
+
+    count = 0;
+    mirror = FALSE;
+    for (i=0;i<path.length;i++) {
+        if (path.p[i] == -1) mirror = TRUE;
+        else {
+            if (g[path.p[i]] == 1 && mirror) count++;
+            else if (g[path.p[i]] == 2 && !mirror) count++;
+            else if (g[path.p[i]] == 4) count++;
+        }
+    }
+    if (count != path.sightings_start) return FALSE;    
+
+    count = 0;
+    mirror = FALSE;
+    for (i=path.length-1;i>=0;i--) {
+        if (path.p[i] == -1) mirror = TRUE;
+        else {
+            if (g[path.p[i]] == 1 && mirror) count++;
+            else if (g[path.p[i]] == 2 && !mirror) count++;
+            else if (g[path.p[i]] == 4) count++;
+        }
+    }
+    if (count != path.sightings_end) return FALSE;  
+
+    return TRUE;
+}
+
+int solve_iterative(game_state *state, struct path *paths) {
+    int solved;
+    int p,i,j,count;
+
+    int *guess;
+    int *possible;
+
+    struct guess loop;
+
+    solved = TRUE;
+    loop.length = state->common->num_total;
+    guess = snewn(state->common->num_total,int);
+    possible = snewn(state->common->num_total,int);
+
+    for (i=0;i<state->common->num_total;i++) {
+        guess[i] = state->guess[i];
+        possible[i] = 0;
+    }
+
+    for (p=0;p<state->common->num_paths;p++) {
+        if (paths[p].num_monsters > 0) {
+            loop.length = paths[p].num_monsters;
+            loop.guess = snewn(paths[p].num_monsters,int);
+            loop.possible = snewn(paths[p].num_monsters,int);
+
+            for (i=0;i<paths[p].num_monsters;i++) {
+                switch (state->guess[paths[p].mapping[i]]) {
+                    case 1: loop.guess[i] = 1; break;
+                    case 2: loop.guess[i] = 2; break;
+                    case 3: loop.guess[i] = 1; break;
+                    case 4: loop.guess[i] = 4; break;
+                    case 5: loop.guess[i] = 1; break;
+                    case 6: loop.guess[i] = 2; break;
+                    case 7: loop.guess[i] = 1; break;
+                }
+                loop.possible[i] = state->guess[paths[p].mapping[i]];
+                possible[paths[p].mapping[i]] = 0;
+            }
+
+            while(TRUE) {
+                for (i=0;i<state->common->num_total;i++) {
+                    guess[i] = state->guess[i];
+                }
+                count = 0;
+                for (i=0;i<paths[p].num_monsters;i++) 
+                    guess[paths[p].mapping[i]] = loop.guess[count++];
+                if (check_numbers(state,guess) &&
+                    check_solution(guess,paths[p]))
+                    for (j=0;j<paths[p].num_monsters;j++)
+                        possible[paths[p].mapping[j]] |= loop.guess[j];
+                if (!next_list(&loop,loop.length-1)) break;
+            }
+            for (i=0;i<paths[p].num_monsters;i++)       
+                state->guess[paths[p].mapping[i]] &=
+                    possible[paths[p].mapping[i]];
+            sfree(loop.possible);
+            sfree(loop.guess);
+        }
+    }
+
+    for (i=0;i<state->common->num_total;i++) {
+        if (state->guess[i] == 3 || state->guess[i] == 5 ||
+            state->guess[i] == 6 || state->guess[i] == 7) {
+            solved = FALSE; break;
+        }
+    }
+
+    sfree(possible);
+    sfree(guess);
+
+    return solved;
+}
+
+int solve_bruteforce(game_state *state, struct path *paths) {
+    int solved, correct;
+    int number_solutions;
+    int p,i;
+
+    struct guess loop;
+
+    loop.guess = snewn(state->common->num_total,int);
+    loop.possible = snewn(state->common->num_total,int);
+
+    for (i=0;i<state->common->num_total;i++) {
+        loop.possible[i] = state->guess[i];
+        switch (state->guess[i]) {
+            case 1: loop.guess[i] = 1; break;
+            case 2: loop.guess[i] = 2; break;
+            case 3: loop.guess[i] = 1; break;
+            case 4: loop.guess[i] = 4; break;
+            case 5: loop.guess[i] = 1; break;
+            case 6: loop.guess[i] = 2; break;
+            case 7: loop.guess[i] = 1; break;
+        }
+    }
+
+    solved = FALSE;
+    number_solutions = 0;
+
+    while (TRUE) {
+
+        correct = TRUE;
+        if (!check_numbers(state,loop.guess)) correct = FALSE;
+        else 
+            for (p=0;p<state->common->num_paths;p++)
+                if (!check_solution(loop.guess,paths[p])) {
+                    correct = FALSE; break;
+                }
+        if (correct) {
+            number_solutions++;
+            solved = TRUE;
+            if(number_solutions > 1) {
+                solved = FALSE;
+                break; 
+            }
+            for (i=0;i<state->common->num_total;i++)
+                state->guess[i] = loop.guess[i];
+        }
+        if (!next_list(&loop,state->common->num_total -1)) {
+            break;
+        }
+    }
+
+    sfree(loop.possible);
+    sfree(loop.guess);
+
+    return solved;
+}
+
+int path_cmp(const void *a, const void *b) {
+    const struct path *pa = (const struct path *)a;
+    const struct path *pb = (const struct path *)b;
+    return pa->num_monsters - pb->num_monsters;
+}
+
+static char *new_game_desc(game_params *params, random_state *rs,
+                           char **aux, int interactive) {
+    int i,count,c,w,h,r,p,g;
+    game_state *new;
+
+    /* Variables for puzzle generation algorithm */
+    int filling;
+    int max_length;
+    int count_ghosts, count_vampires, count_zombies;
+    int abort;
+    float ratio;
+    
+    /* Variables for solver algorithm */
+    int solved_iterative, solved_bruteforce, contains_inconsistency,
+        count_ambiguous;
+    int iterative_depth;
+    int *old_guess;
+
+    /* Variables for game description generation */
+    int x,y;
+    char *e;
+    char *desc; 
+
+    i = 0;
+    while (TRUE) {
+        new = new_state(params);
+        abort = FALSE;
+
+        /* Fill grid with random mirrors and (later to be populated)
+         * empty monster cells */
+        count = 0;
+        for (h=1;h<new->common->params.h+1;h++)
+        for (w=1;w<new->common->params.w+1;w++) {
+            c = random_upto(rs,5);
+            if (c >= 2) {
+                new->common->grid[w+h*(new->common->params.w+2)] = CELL_EMPTY;
+                new->common->xinfo[w+h*(new->common->params.w+2)] = count++;
+            }
+            else if (c == 0) {
+                new->common->grid[w+h*(new->common->params.w+2)] = 
+                    CELL_MIRROR_L;
+                new->common->xinfo[w+h*(new->common->params.w+2)] = -1;
+            }
+            else {
+                new->common->grid[w+h*(new->common->params.w+2)] =
+                    CELL_MIRROR_R;
+                new->common->xinfo[w+h*(new->common->params.w+2)] = -1;         
+            }
+        }
+        new->common->num_total = count; /* Total number of monsters in maze */
+
+        /* Puzzle is boring if it has too few monster cells. Discard
+         * grid, make new grid */
+        if (new->common->num_total <= 4) {
+            free_game(new);
+            continue;
+        }
+
+        /* Monsters / Mirrors ratio should be balanced */
+        ratio = (float)new->common->num_total /
+            (float)(new->common->params.w * new->common->params.h);
+        if (ratio < 0.48 || ratio > 0.78) {
+            free_game(new);
+            continue;
+        }        
+
+        /* Assign clue identifiers */   
+        for (r=0;r<2*(new->common->params.w+new->common->params.h);r++) {
+            int x,y,gridno;
+            gridno = range2grid(r,new->common->params.w,new->common->params.h,
+                                &x,&y);
+            new->common->grid[x+y*(new->common->params.w +2)] = gridno;
+            new->common->xinfo[x+y*(new->common->params.w +2)] = 0;
+        }
+        /* The four corners don't matter at all for the game. Set them
+         * all to zero, just to have a nice data structure */
+        new->common->grid[0] = 0;        
+        new->common->xinfo[0] = 0;      
+        new->common->grid[new->common->params.w+1] = 0; 
+        new->common->xinfo[new->common->params.w+1] = 0;
+        new->common->grid[new->common->params.w+1 + (new->common->params.h+1)*(new->common->params.w+2)] = 0; 
+        new->common->xinfo[new->common->params.w+1 + (new->common->params.h+1)*(new->common->params.w+2)] = 0;
+        new->common->grid[(new->common->params.h+1)*(new->common->params.w+2)] = 0; 
+        new->common->xinfo[(new->common->params.h+1)*(new->common->params.w+2)] = 0;
+
+        /* Initialize solution vector */
+        new->guess = snewn(new->common->num_total,int);
+        for (g=0;g<new->common->num_total;g++) new->guess[g] = 7;
+
+        /* Initialize fixed flag from common. Not needed for the
+         * puzzle generator; initialize it for having clean code */
+        new->common->fixed = snewn(new->common->num_total,int);
+        for (g=0;g<new->common->num_total;g++)
+            new->common->fixed[g] = FALSE;
+
+        /* paths generation */
+        make_paths(new);
+
+        /* Grid is invalid if max. path length > threshold. Discard
+         * grid, make new one */
+        switch (new->common->params.diff) {
+            case DIFF_EASY:     max_length = min(new->common->params.w,new->common->params.h) + 1; break;
+            case DIFF_NORMAL:   max_length = (max(new->common->params.w,new->common->params.h) * 3) / 2; break;
+            case DIFF_TRICKY:   max_length = 9; break;
+            default:            max_length = 9; break;
+        }
+
+        for (p=0;p<new->common->num_paths;p++) {
+            if (new->common->paths[p].num_monsters > max_length) {
+                abort = TRUE;
+            }
+        }
+        if (abort) {
+            free_game(new);
+            continue;
+        }
+
+        qsort(new->common->paths, new->common->num_paths,
+              sizeof(struct path), path_cmp);
+
+        /* Grid monster initialization */
+        /*  For easy puzzles, we try to fill nearly the whole grid
+            with unique solution paths (up to 2) For more difficult
+            puzzles, we fill only roughly half the grid, and choose
+            random monsters for the rest For hard puzzles, we fill
+            even less paths with unique solutions */
+
+        switch (new->common->params.diff) {
+            case DIFF_EASY:   filling = 2; break;
+            case DIFF_NORMAL: filling = min( (new->common->params.w+new->common->params.h) , (new->common->num_total)/2 ); break;
+            case DIFF_TRICKY: filling = max( (new->common->params.w+new->common->params.h) , (new->common->num_total)/2 ); break;
+            default:          filling = 0; break;
+        }
+
+        count = 0;
+        while ( (count_monsters(new, &count_ghosts, &count_vampires,
+                                &count_zombies)) > filling) {
+            if ((count) >= new->common->num_paths) break;
+            if (new->common->paths[count].num_monsters == 0) {
+                count++;
+                continue;
+            }
+            get_unique(new,count,rs);
+            count++;
+        }
+
+        /* Fill any remaining ambiguous entries with random monsters */ 
+        for(g=0;g<new->common->num_total;g++) {
+            if (new->guess[g] == 7) {
+                r = random_upto(rs,3);
+                new->guess[g] = (r == 0) ? 1 : ( (r == 1) ? 2 : 4 );        
+            }
+        }
+
+        /*  Determine all hints */
+        count_monsters(new, &new->common->num_ghosts,
+                       &new->common->num_vampires, &new->common->num_zombies);
+
+        /* Puzzle is trivial if it has only one type of monster. Discard. */
+        if ((new->common->num_ghosts == 0 && new->common->num_vampires == 0) ||
+            (new->common->num_ghosts == 0 && new->common->num_zombies == 0) ||
+            (new->common->num_vampires == 0 && new->common->num_zombies == 0)) {
+            free_game(new);
+            continue;
+        }
+
+        /* Discard puzzle if difficulty Tricky, and it has only 1
+         * member of any monster type */
+        if (new->common->params.diff == DIFF_TRICKY && 
+            (new->common->num_ghosts <= 1 ||
+             new->common->num_vampires <= 1 || new->common->num_zombies <= 1)) {
+            free_game(new);
+            continue;
+        }
+
+        for (w=1;w<new->common->params.w+1;w++)
+        for (h=1;h<new->common->params.h+1;h++) {
+            c = new->common->xinfo[w+h*(new->common->params.w+2)];
+            if (c >= 0) {
+                if (new->guess[c] == 1) new->common->grid[w+h*(new->common->params.w+2)] = CELL_GHOST;
+                if (new->guess[c] == 2) new->common->grid[w+h*(new->common->params.w+2)] = CELL_VAMPIRE;
+                if (new->guess[c] == 4) new->common->grid[w+h*(new->common->params.w+2)] = CELL_ZOMBIE;                 
+            }
+        }
+
+        /* Prepare path information needed by the solver (containing all hints) */  
+        for (p=0;p<new->common->num_paths;p++) {
+            int mirror,x,y;
+
+            new->common->paths[p].sightings_start = 0;
+            new->common->paths[p].sightings_end = 0;
+            
+            mirror = FALSE;
+            for (g=0;g<new->common->paths[p].length;g++) {
+
+                if (new->common->paths[p].p[g] == -1) mirror = TRUE;
+                else {
+                    if      (new->guess[new->common->paths[p].p[g]] == 1 && mirror == TRUE)  (new->common->paths[p].sightings_start)++;
+                    else if (new->guess[new->common->paths[p].p[g]] == 2 && mirror == FALSE) (new->common->paths[p].sightings_start)++;
+                    else if (new->guess[new->common->paths[p].p[g]] == 4)                    (new->common->paths[p].sightings_start)++;
+                }
+            }
+
+            mirror = FALSE;
+            for (g=new->common->paths[p].length-1;g>=0;g--) {
+                if (new->common->paths[p].p[g] == -1) mirror = TRUE;
+                else {
+                    if      (new->guess[new->common->paths[p].p[g]] == 1 && mirror == TRUE)  (new->common->paths[p].sightings_end)++;
+                    else if (new->guess[new->common->paths[p].p[g]] == 2 && mirror == FALSE) (new->common->paths[p].sightings_end)++;
+                    else if (new->guess[new->common->paths[p].p[g]] == 4)                    (new->common->paths[p].sightings_end)++;
+                }
+            }
+
+            range2grid(new->common->paths[p].grid_start,
+                       new->common->params.w,new->common->params.h,&x,&y);
+            new->common->grid[x+y*(new->common->params.w +2)] =
+                new->common->paths[p].sightings_start;
+            range2grid(new->common->paths[p].grid_end,
+                       new->common->params.w,new->common->params.h,&x,&y);
+            new->common->grid[x+y*(new->common->params.w +2)] =
+                new->common->paths[p].sightings_end;
+        }
+
+        /* Try to solve the puzzle with the iterative solver */
+        old_guess = snewn(new->common->num_total,int);
+        for (p=0;p<new->common->num_total;p++) {
+            new->guess[p] = 7;
+            old_guess[p] = 7;
+        }
+        iterative_depth = 0;
+        solved_iterative = FALSE;
+        contains_inconsistency = FALSE;
+        count_ambiguous = 0;
+
+        while (TRUE) {
+            int no_change;          
+            no_change = TRUE;
+            solved_iterative = solve_iterative(new,new->common->paths);
+            iterative_depth++;      
+            for (p=0;p<new->common->num_total;p++) {
+                if (new->guess[p] != old_guess[p]) no_change = FALSE;
+                old_guess[p] = new->guess[p];
+                if (new->guess[p] == 0) contains_inconsistency = TRUE;
+            }
+            if (solved_iterative || no_change) break;
+        } 
+
+        /* If necessary, try to solve the puzzle with the brute-force solver */
+        solved_bruteforce = FALSE;  
+        if (new->common->params.diff != DIFF_EASY &&
+            !solved_iterative && !contains_inconsistency) {
+            for (p=0;p<new->common->num_total;p++)
+                if (new->guess[p] != 1 && new->guess[p] != 2 &&
+                    new->guess[p] != 4) count_ambiguous++;
+
+            solved_bruteforce = solve_bruteforce(new, new->common->paths);
+        }   
+
+        /*  Determine puzzle difficulty level */    
+        if (new->common->params.diff == DIFF_EASY && solved_iterative &&
+            iterative_depth <= 3 && !contains_inconsistency) { 
+/*          printf("Puzzle level: EASY Level %d Ratio %f Ambiguous %d (Found after %i tries)\n",iterative_depth, ratio, count_ambiguous, i); */
+            break;
+        }
+
+        if (new->common->params.diff == DIFF_NORMAL &&
+            ((solved_iterative && iterative_depth > 3) ||
+             (solved_bruteforce && count_ambiguous < 4)) &&
+            !contains_inconsistency) {  
+/*          printf("Puzzle level: NORMAL Level %d Ratio %f Ambiguous %d (Found after %d tries)\n", iterative_depth, ratio, count_ambiguous, i); */
+            break;
+        }
+        if (new->common->params.diff == DIFF_TRICKY &&
+            solved_bruteforce && iterative_depth > 0 &&
+            count_ambiguous >= 4 && !contains_inconsistency) {
+/*          printf("Puzzle level: TRICKY Level %d Ratio %f Ambiguous %d (Found after %d tries)\n", iterative_depth, ratio, count_ambiguous, i); */
+            break;
+        }
+
+        /* If puzzle is not solvable or does not satisfy the desired
+         * difficulty level, free memory and start from scratch */    
+        sfree(old_guess);
+        free_game(new);
+        i++;
+    }
+    
+    /* We have a valid puzzle! */
+    
+    desc = snewn(10 + new->common->wh +
+                 6*(new->common->params.w + new->common->params.h), char);
+    e = desc;
+
+    /* Encode monster counts */
+    e += sprintf(e, "%d,", new->common->num_ghosts);
+    e += sprintf(e, "%d,", new->common->num_vampires);
+    e += sprintf(e, "%d,", new->common->num_zombies);
+
+    /* Encode grid */
+    count = 0;
+    for (y=1;y<new->common->params.h+1;y++)
+    for (x=1;x<new->common->params.w+1;x++) {
+        c = new->common->grid[x+y*(new->common->params.w+2)];
+        if (count > 25) {
+            *e++ = 'z';
+            count -= 26;
+        }
+        if (c != CELL_MIRROR_L && c != CELL_MIRROR_R) {
+            count++;
+        }
+        else if (c == CELL_MIRROR_L) {
+            if (count > 0) *e++ = (count-1 + 'a');
+            *e++ = 'L';
+            count = 0;
+        }
+        else {
+            if (count > 0) *e++ = (count-1 + 'a');
+            *e++ = 'R';
+            count = 0;          
+        }
+    }
+    if (count > 0) *e++ = (count-1 + 'a');
+
+    /* Encode hints */
+    for (p=0;p<2*(new->common->params.w + new->common->params.h);p++) {
+        range2grid(p,new->common->params.w,new->common->params.h,&x,&y);
+        e += sprintf(e, ",%d", new->common->grid[x+y*(new->common->params.w+2)]);
+    }
+
+    *e++ = '\0';
+    desc = sresize(desc, e - desc, char);
+
+    sfree(old_guess);
+    free_game(new);
+
+    return desc;
+}
+
+void num2grid(int num, int width, int height, int *x, int *y) {
+    *x = 1+(num%width);
+    *y = 1+(num/width);
+    return;
+}
+
+static game_state *new_game(midend *me, game_params *params, char *desc) {
+    int i;
+    int n;
+    int count;
+
+    game_state *state = new_state(params);
+
+    state->common->num_ghosts = atoi(desc);
+    while (*desc && isdigit((unsigned char)*desc)) desc++;
+    desc++;
+    state->common->num_vampires = atoi(desc);
+    while (*desc && isdigit((unsigned char)*desc)) desc++;
+    desc++;
+    state->common->num_zombies = atoi(desc);
+    while (*desc && isdigit((unsigned char)*desc)) desc++;
+    desc++;
+
+    state->common->num_total = state->common->num_ghosts + state->common->num_vampires + state->common->num_zombies;
+
+    state->guess = snewn(state->common->num_total,int);
+    state->pencils = snewn(state->common->num_total,unsigned char);
+    state->common->fixed = snewn(state->common->num_total,int);
+    for (i=0;i<state->common->num_total;i++) {
+        state->guess[i] = 7;
+        state->pencils[i] = 0;
+        state->common->fixed[i] = FALSE;
+    }
+    for (i=0;i<state->common->wh;i++)
+        state->cell_errors[i] = FALSE;
+    for (i=0;i<2*state->common->num_paths;i++)
+        state->hint_errors[i] = FALSE;
+    for (i=0;i<3;i++)
+        state->count_errors[i] = FALSE;
+
+    count = 0;
+    n = 0;
+    while (*desc != ',') {
+        int c;
+        int x,y;
+
+        if (*desc == 'L') {
+            num2grid(n,state->common->params.w,state->common->params.h,&x,&y);
+            state->common->grid[x+y*(state->common->params.w +2)] = CELL_MIRROR_L;
+            state->common->xinfo[x+y*(state->common->params.w+2)] = -1;
+            n++;
+        }
+        else if (*desc == 'R') {
+            num2grid(n,state->common->params.w,state->common->params.h,&x,&y);
+            state->common->grid[x+y*(state->common->params.w +2)] = CELL_MIRROR_R;
+            state->common->xinfo[x+y*(state->common->params.w+2)] = -1;
+            n++;
+        }
+        else if (*desc == 'G') {
+            num2grid(n,state->common->params.w,state->common->params.h,&x,&y);
+            state->common->grid[x+y*(state->common->params.w +2)] = CELL_GHOST;
+            state->common->xinfo[x+y*(state->common->params.w+2)] = count;
+            state->guess[count] = 1;
+            state->common->fixed[count++] = TRUE;
+            n++;
+        }
+        else if (*desc == 'V') {
+            num2grid(n,state->common->params.w,state->common->params.h,&x,&y);
+            state->common->grid[x+y*(state->common->params.w +2)] = CELL_VAMPIRE;
+            state->common->xinfo[x+y*(state->common->params.w+2)] = count;
+            state->guess[count] = 2;
+            state->common->fixed[count++] = TRUE;
+            n++;
+        }
+        else if (*desc == 'Z') {
+            num2grid(n,state->common->params.w,state->common->params.h,&x,&y);
+            state->common->grid[x+y*(state->common->params.w +2)] = CELL_ZOMBIE;
+            state->common->xinfo[x+y*(state->common->params.w+2)] = count;
+            state->guess[count] = 4;
+            state->common->fixed[count++] = TRUE;
+            n++;
+        }
+        else {
+            c = *desc - ('a' -1);
+            while (c-- > 0) {
+                num2grid(n,state->common->params.w,state->common->params.h,&x,&y);
+                state->common->grid[x+y*(state->common->params.w +2)] = CELL_EMPTY;
+                state->common->xinfo[x+y*(state->common->params.w+2)] = count;
+                state->guess[count] = 7;
+                state->common->fixed[count++] = FALSE;
+                n++;
+            }
+        }
+        desc++;
+    }
+    desc++;
+
+    for (i=0;i<2*(state->common->params.w + state->common->params.h);i++) {
+        int x,y;
+        int sights;
+
+        sights = atoi(desc);
+        while (*desc && isdigit((unsigned char)*desc)) desc++;
+        desc++;
+
+
+        range2grid(i,state->common->params.w,state->common->params.h,&x,&y);
+        state->common->grid[x+y*(state->common->params.w +2)] = sights;
+        state->common->xinfo[x+y*(state->common->params.w +2)] = -2;
+    }
+
+    state->common->grid[0] = 0;
+    state->common->xinfo[0] = -2;
+    state->common->grid[state->common->params.w+1] = 0;
+    state->common->xinfo[state->common->params.w+1] = -2;
+    state->common->grid[state->common->params.w+1 + (state->common->params.h+1)*(state->common->params.w+2)] = 0;
+    state->common->xinfo[state->common->params.w+1 + (state->common->params.h+1)*(state->common->params.w+2)] = -2;
+    state->common->grid[(state->common->params.h+1)*(state->common->params.w+2)] = 0;
+    state->common->xinfo[(state->common->params.h+1)*(state->common->params.w+2)] = -2;
+
+    make_paths(state);
+    qsort(state->common->paths, state->common->num_paths, sizeof(struct path), path_cmp);
+
+    return state;
+}
+
+static char *validate_desc(game_params *params, char *desc) {
+    int i;
+    int w = params->w, h = params->h;
+    int wh = w*h;
+    int area;
+    int monsters;
+    int monster_count;
+    char *desc_s = desc;
+        
+    for (i=0;i<3;i++) {
+        if (!*desc) return "Faulty game description";
+        while (*desc && isdigit((unsigned char)*desc)) { desc++; }
+        if (*desc != ',') return "Invalid character in number list";
+        desc++;
+    }
+    desc = desc_s;
+    
+    area = monsters = monster_count = 0;
+    for (i=0;i<3;i++) {
+        monster_count += atoi(desc);
+        while (*desc && isdigit((unsigned char)*desc)) desc++;
+        desc++;
+    }
+    while (*desc && *desc != ',') {
+        if (*desc >= 'a' && *desc <= 'z') {
+            area += *desc - 'a' +1; monsters += *desc - 'a' +1;
+        } else if (*desc == 'G' || *desc == 'V' || *desc == 'Z') {
+            area++; monsters++;
+        } else if (*desc == 'L' || *desc == 'R') {
+            area++;
+        } else
+            return "Invalid character in grid specification";
+        desc++;
+    }
+    if (area < wh) return "Not enough data to fill grid";
+    else if (area > wh) return "Too much data to fill grid";
+    if (monsters != monster_count)
+        return "Monster numbers do not match grid spaces";
+
+    for (i = 0; i < 2*(w+h); i++) {
+        if (!*desc) return "Not enough numbers given after grid specification";
+        else if (*desc != ',') return "Invalid character in number list";
+        desc++;
+        while (*desc && isdigit((unsigned char)*desc)) { desc++; }
+    }
+
+    if (*desc) return "Unexpected additional data at end of game description";
+
+    return NULL;
+}
+
+static char *solve_game(game_state *state_start, game_state *currstate, char *aux, char **error) {
+    int p;
+    int *old_guess;
+    int iterative_depth;
+    int solved_iterative, solved_bruteforce, contains_inconsistency,
+        count_ambiguous;
+
+    int i;
+    char *move, *c;
+
+    game_state *solve_state = dup_game(currstate);
+
+    old_guess = snewn(solve_state->common->num_total,int);
+    for (p=0;p<solve_state->common->num_total;p++) {
+        if (solve_state->common->fixed[p]) {
+            old_guess[p] = solve_state->guess[p] = state_start->guess[p];
+        }
+        else {
+            old_guess[p] = solve_state->guess[p] = 7;
+        }
+    }
+    iterative_depth = 0;
+    solved_iterative = FALSE;
+    contains_inconsistency = FALSE;
+    count_ambiguous = 0;
+    
+    /* Try to solve the puzzle with the iterative solver */
+    while (TRUE) {
+        int no_change;
+        no_change = TRUE;
+        solved_iterative =
+            solve_iterative(solve_state,solve_state->common->paths);
+        iterative_depth++;
+        for (p=0;p<solve_state->common->num_total;p++) {
+            if (solve_state->guess[p] != old_guess[p]) no_change = FALSE;
+            old_guess[p] = solve_state->guess[p];
+            if (solve_state->guess[p] == 0) contains_inconsistency = TRUE;
+        }
+        if (solved_iterative || no_change || contains_inconsistency) break;
+    }
+
+    if (contains_inconsistency) {
+        *error = "Puzzle is inconsistent";
+        sfree(old_guess);
+        free_game(solve_state);
+        return NULL;
+    }
+
+    /* If necessary, try to solve the puzzle with the brute-force solver */
+    solved_bruteforce = FALSE;  
+    if (!solved_iterative) {
+        for (p=0;p<solve_state->common->num_total;p++)
+            if (solve_state->guess[p] != 1 && solve_state->guess[p] != 2 &&
+                solve_state->guess[p] != 4) count_ambiguous++;
+        solved_bruteforce =
+            solve_bruteforce(solve_state, solve_state->common->paths);
+    }
+
+    if (!solved_iterative && !solved_bruteforce) {
+        *error = "Puzzle is unsolvable";
+        sfree(old_guess);
+        free_game(solve_state);
+        return NULL;
+    }
+
+/*  printf("Puzzle solved at level %s, iterations %d, ambiguous %d\n", (solved_bruteforce ? "TRICKY" : "NORMAL"), iterative_depth, count_ambiguous); */
+
+    move = snewn(solve_state->common->num_total * 4 +2, char);
+    c = move;
+    *c++='S';
+    for (i = 0; i < solve_state->common->num_total; i++) {
+        if (solve_state->guess[i] == 1) c += sprintf(c, ";G%d", i);
+        if (solve_state->guess[i] == 2) c += sprintf(c, ";V%d", i);
+        if (solve_state->guess[i] == 4) c += sprintf(c, ";Z%d", i);
+    }
+    *c++ = '\0';
+    move = sresize(move, c - move, char);
+
+    sfree(old_guess);   
+    free_game(solve_state);
+    return move;
+}
+
+static int game_can_format_as_text_now(game_params *params) {
+    return TRUE;
+}
+
+static char *game_text_format(game_state *state) {
+    int w,h,c,r,xi,g;
+    char *ret;
+    char buf[120];
+
+    ret = snewn(50 + 6*(state->common->params.w +2) +
+                6*(state->common->params.h+2) +
+                3*(state->common->params.w * state->common->params.h), char);
+
+    sprintf(ret,"G: %d V: %d Z: %d\n\n",state->common->num_ghosts,
+            state->common->num_vampires, state->common->num_zombies);
+
+    for (h=0;h<state->common->params.h+2;h++) {
+        for (w=0;w<state->common->params.w+2;w++) {
+            c = state->common->grid[w+h*(state->common->params.w+2)];
+            xi = state->common->xinfo[w+h*(state->common->params.w+2)];
+            r = grid2range(w,h,state->common->params.w,state->common->params.h);
+            if (r != -1) {
+                sprintf(buf,"%2d", c);  strcat(ret,buf);
+            } else if (c == CELL_MIRROR_L) {
+                sprintf(buf," \\"); strcat(ret,buf);
+            } else if (c == CELL_MIRROR_R) {
+                sprintf(buf," /"); strcat(ret,buf);
+            } else if (xi >= 0) {
+                g = state->guess[xi];
+                if (g == 1)      { sprintf(buf," G"); strcat(ret,buf); }
+                else if (g == 2) { sprintf(buf," V"); strcat(ret,buf); }
+                else if (g == 4) { sprintf(buf," Z"); strcat(ret,buf); }
+                else             { sprintf(buf," ."); strcat(ret,buf); }
+            } else {
+                sprintf(buf,"  "); strcat(ret,buf);
+            }
+        }
+        sprintf(buf,"\n"); strcat(ret,buf);
+    }
+
+    return ret;
+}
+
+struct game_ui {
+    int hx, hy;                         /* as for solo.c, highlight pos */
+    int hshow, hpencil, hcursor;        /* show state, type, and ?cursor. */
+    int ascii;
+};
+
+static game_ui *new_ui(game_state *state) {
+    game_ui *ui = snew(game_ui);
+    ui->hx = ui->hy = 0;
+    ui->hpencil = ui->hshow = ui->hcursor = 0;
+    ui->ascii = FALSE;
+    return ui;
+}
+
+static void free_ui(game_ui *ui) {
+    sfree(ui);
+    return;
+}
+
+static char *encode_ui(game_ui *ui) {
+    return NULL;
+}
+
+static void decode_ui(game_ui *ui, char *encoding) {
+    return;
+}
+
+static void game_changed_state(game_ui *ui, game_state *oldstate, game_state *newstate) {
+    /* See solo.c; if we were pencil-mode highlighting and
+     * somehow a square has just been properly filled, cancel
+     * pencil mode. */
+    if (ui->hshow && ui->hpencil && !ui->hcursor) {
+        int g = newstate->guess[newstate->common->xinfo[ui->hx + ui->hy*(newstate->common->params.w+2)]];
+        if (g == 1 || g == 2 || g == 4)
+            ui->hshow = 0;
+    }
+}
+
+struct game_drawstate {
+    int tilesize, started, solved;
+    int w, h;
+        
+    int *monsters;
+    unsigned char *pencils;
+
+    unsigned char count_errors[3];
+    unsigned char *cell_errors;
+    unsigned char *hint_errors;
+
+    int hx, hy, hshow, hpencil; /* as for game_ui. */
+    int hflash;
+    int ascii;
+};
+
+#define TILESIZE (ds->tilesize)
+#define BORDER (TILESIZE/2)
+
+static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds,
+                            int x, int y, int button) {
+    int gx,gy;
+    int g,xi;
+    char buf[80]; 
+
+    gx = ((x-BORDER-1) / TILESIZE );
+    gy = ((y-BORDER-2) / TILESIZE ) - 1;
+
+    if (button == 'a' || button == 'A') {
+        ds->ascii = ui->ascii ? FALSE : TRUE;
+        return "";      
+    }
+    
+    if (ui->hshow == 1 && ui->hpencil == 0) {
+        xi = state->common->xinfo[ui->hx + ui->hy*(state->common->params.w+2)];
+        if (xi >= 0 && !state->common->fixed[xi]) {
+            if (button == 'g' || button == 'G' || button == '1') {
+                if (!ui->hcursor) ui->hshow = 0;
+                sprintf(buf,"G%d",xi);
+                return dupstr(buf);
+            }
+            if (button == 'v' || button == 'V' || button == '2') {
+                if (!ui->hcursor) ui->hshow = 0;
+                sprintf(buf,"V%d",xi);
+                return dupstr(buf);
+            }
+            if (button == 'z' || button == 'Z' || button == '3') {
+                if (!ui->hcursor) ui->hshow = 0;
+                sprintf(buf,"Z%d",xi);
+                return dupstr(buf);
+            }
+            if (button == 'e' || button == 'E' || button == CURSOR_SELECT2 ||
+                button == '0' || button == '\b' ) {
+                if (!ui->hcursor) ui->hshow = 0;
+                sprintf(buf,"E%d",xi);
+                return dupstr(buf);
+            }
+        }       
+    }
+
+    if (IS_CURSOR_MOVE(button)) {
+        if (ui->hx == 0 && ui->hy == 0) {
+            ui->hx = 1;
+            ui->hy = 1;
+        }
+        else switch (button) {
+            case CURSOR_UP:     ui->hy -= (ui->hy > 1)     ? 1 : 0; break;
+            case CURSOR_DOWN:   ui->hy += (ui->hy < ds->h) ? 1 : 0; break;
+            case CURSOR_RIGHT:  ui->hx += (ui->hx < ds->w) ? 1 : 0; break;
+            case CURSOR_LEFT:   ui->hx -= (ui->hx > 1)     ? 1 : 0; break;
+        }
+        ui->hshow = ui->hcursor = 1;
+        return "";
+    }
+    if (ui->hshow && button == CURSOR_SELECT) {
+        ui->hpencil = 1 - ui->hpencil;
+        ui->hcursor = 1;
+        return "";
+    }
+
+    if (ui->hshow == 1 && ui->hpencil == 1) {
+        xi = state->common->xinfo[ui->hx + ui->hy*(state->common->params.w+2)];
+        if (xi >= 0 && !state->common->fixed[xi]) {
+            if (button == 'g' || button == 'G' || button == '1') {
+                sprintf(buf,"g%d",xi);
+                                ui->hpencil = ui->hshow = 0;
+                return dupstr(buf);
+            }
+            if (button == 'v' || button == 'V' || button == '2') {
+                sprintf(buf,"v%d",xi);
+                                ui->hpencil = ui->hshow = 0;
+                return dupstr(buf);
+            }
+            if (button == 'z' || button == 'Z' || button == '3') {
+                sprintf(buf,"z%d",xi);
+                                ui->hpencil = ui->hshow = 0;
+                return dupstr(buf);
+            }
+            if (button == 'e' || button == 'E' || button == CURSOR_SELECT2 ||
+                button == '0' || button == '\b') {
+                if (!ui->hcursor) ui->hshow = 0;
+                sprintf(buf,"E%d",xi);
+                                ui->hpencil = ui->hshow = 0;
+                return dupstr(buf);
+            }
+        }       
+    }
+
+    if (gx > 0 && gx < ds->w+1 && gy > 0 && gy < ds->h+1) {
+        xi = state->common->xinfo[gx+gy*(state->common->params.w+2)];
+        if (xi >= 0 && !state->common->fixed[xi]) {
+            g = state->guess[xi];
+            if (ui->hshow == 0) {
+                if (button == LEFT_BUTTON) {
+                    ui->hshow = 1; ui->hpencil = 0; ui->hcursor = 0;
+                    ui->hx = gx; ui->hy = gy;
+                    return "";
+                }
+                else if (button == RIGHT_BUTTON && g == 7) {
+                    ui->hshow = 1; ui->hpencil = 1; ui->hcursor = 0;
+                    ui->hx = gx; ui->hy = gy;
+                    return "";
+                }
+            }
+            else if (ui->hshow == 1) {
+                if (button == LEFT_BUTTON) {
+                    if (ui->hpencil == 0) {
+                        if (gx == ui->hx && gy == ui->hy) {
+                            ui->hshow = 0; ui->hpencil = 0; ui->hcursor = 0;
+                            ui->hx = 0; ui->hy = 0;
+                            return "";
+                        }
+                        else {
+                            ui->hshow = 1; ui->hpencil = 0; ui->hcursor = 0;
+                            ui->hx = gx; ui->hy = gy;
+                            return "";
+                        }
+                    }
+                    else {
+                        ui->hshow = 1; ui->hpencil = 0; ui->hcursor = 0;
+                        ui->hx = gx; ui->hy = gy;
+                        return "";
+                    }
+                }
+                else if (button == RIGHT_BUTTON) {
+                    if (ui->hpencil == 0 && g == 7) {
+                        ui->hshow = 1; ui->hpencil = 1; ui->hcursor = 0;
+                        ui->hx = gx; ui->hy = gy;
+                        return "";
+                    }
+                    else {
+                        if (gx == ui->hx && gy == ui->hy) {
+                            ui->hshow = 0; ui->hpencil = 0; ui->hcursor = 0;
+                            ui->hx = 0; ui->hy = 0;
+                            return "";
+                        }
+                        else if (g == 7) {
+                            ui->hshow = 1; ui->hpencil = 1; ui->hcursor = 0;
+                            ui->hx = gx; ui->hy = gy;
+                            return "";
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    return NULL;
+}
+
+int check_numbers_draw(game_state *state, int *guess) {
+    int valid, filled;
+    int i,x,y,xy;
+    int count_ghosts, count_vampires, count_zombies;
+
+    count_ghosts = count_vampires = count_zombies = 0;  
+    for (i=0;i<state->common->num_total;i++) {
+        if (guess[i] == 1) count_ghosts++;
+        if (guess[i] == 2) count_vampires++;
+        if (guess[i] == 4) count_zombies++;
+    }
+
+    valid = TRUE;
+    filled = (count_ghosts + count_vampires + count_zombies >=
+              state->common->num_total);
+
+    if (count_ghosts > state->common->num_ghosts ||
+        (filled && count_ghosts != state->common->num_ghosts) ) {
+        valid = FALSE; 
+        state->count_errors[0] = TRUE; 
+        for (x=1;x<state->common->params.w+1;x++)
+        for (y=1;y<state->common->params.h+1;y++) {
+            xy = x+y*(state->common->params.w+2);
+            if (state->common->xinfo[xy] >= 0 &&
+                guess[state->common->xinfo[xy]] == 1)
+                state->cell_errors[xy] = TRUE;
+        }
+    }
+    if (count_vampires > state->common->num_vampires ||
+        (filled && count_vampires != state->common->num_vampires) ) {
+        valid = FALSE; 
+        state->count_errors[1] = TRUE; 
+        for (x=1;x<state->common->params.w+1;x++)
+        for (y=1;y<state->common->params.h+1;y++) {
+            xy = x+y*(state->common->params.w+2);
+            if (state->common->xinfo[xy] >= 0 &&
+                guess[state->common->xinfo[xy]] == 2)
+                state->cell_errors[xy] = TRUE;
+        }
+    }
+    if (count_zombies > state->common->num_zombies ||
+        (filled && count_zombies != state->common->num_zombies) )  {
+        valid = FALSE; 
+        state->count_errors[2] = TRUE; 
+        for (x=1;x<state->common->params.w+1;x++)
+        for (y=1;y<state->common->params.h+1;y++) {
+            xy = x+y*(state->common->params.w+2);
+            if (state->common->xinfo[xy] >= 0 &&
+                guess[state->common->xinfo[xy]] == 4)
+                state->cell_errors[xy] = TRUE;
+        }
+    }
+
+    return valid;
+}
+
+int check_path_solution(game_state *state, int p) {
+    int i;
+    int mirror;
+    int count;
+    int correct;
+    int unfilled;
+
+    count = 0;
+    mirror = FALSE;
+    correct = TRUE;
+
+    unfilled = 0;
+    for (i=0;i<state->common->paths[p].length;i++) {
+        if (state->common->paths[p].p[i] == -1) mirror = TRUE;
+        else {
+            if (state->guess[state->common->paths[p].p[i]] == 1 && mirror)
+                count++;
+            else if (state->guess[state->common->paths[p].p[i]] == 2 && !mirror)
+                count++;
+            else if (state->guess[state->common->paths[p].p[i]] == 4)
+                count++;
+            else if (state->guess[state->common->paths[p].p[i]] == 7)
+                unfilled++;
+        }
+    }
+
+    if (unfilled == 0 && count != state->common->paths[p].sightings_start) {
+        correct = FALSE;
+        state->hint_errors[state->common->paths[p].grid_start] = TRUE;
+    }
+
+    count = 0;
+    mirror = FALSE;
+    unfilled = 0;
+    for (i=state->common->paths[p].length-1;i>=0;i--) {
+        if (state->common->paths[p].p[i] == -1) mirror = TRUE;
+        else {
+            if (state->guess[state->common->paths[p].p[i]] == 1 && mirror)
+                count++;
+            else if (state->guess[state->common->paths[p].p[i]] == 2 && !mirror)
+                count++;
+            else if (state->guess[state->common->paths[p].p[i]] == 4)
+                count++;
+            else if (state->guess[state->common->paths[p].p[i]] == 7)
+                unfilled++;
+        }
+    }
+
+    if (unfilled == 0 && count != state->common->paths[p].sightings_end) {
+        correct = FALSE;
+        state->hint_errors[state->common->paths[p].grid_end] = TRUE;
+    }
+
+    if (!correct) {
+        for (i=0;i<state->common->paths[p].length;i++) 
+            state->cell_errors[state->common->paths[p].xy[i]] = TRUE;
+    }
+
+    return correct;
+}
+
+static game_state *execute_move(game_state *state, char *move) {
+    int x,n,p,i;
+    char c;
+    int correct; 
+    int solver; 
+
+    game_state *ret = dup_game(state);
+    solver = FALSE;
+
+    while (*move) {
+        c = *move;
+        if (c == 'S') {
+            move++;
+            solver = TRUE;
+        }
+        if (c == 'G' || c == 'V' || c == 'Z' || c == 'E' ||
+            c == 'g' || c == 'v' || c == 'z') {
+            move++;
+            sscanf(move, "%d%n", &x, &n);
+            if (c == 'G') ret->guess[x] = 1;
+            if (c == 'V') ret->guess[x] = 2;
+            if (c == 'Z') ret->guess[x] = 4;
+            if (c == 'E') { ret->guess[x] = 7; ret->pencils[x] = 0; }
+            if (c == 'g') ret->pencils[x] ^= 1;
+            if (c == 'v') ret->pencils[x] ^= 2;
+            if (c == 'z') ret->pencils[x] ^= 4;
+            move += n;
+        }
+        if (*move == ';') move++;
+    }
+
+    correct = TRUE;
+
+    for (i=0;i<ret->common->wh;i++) ret->cell_errors[i] = FALSE;
+    for (i=0;i<2*ret->common->num_paths;i++) ret->hint_errors[i] = FALSE;
+    for (i=0;i<3;i++) ret->count_errors[i] = FALSE;
+
+    if (!check_numbers_draw(ret,ret->guess)) correct = FALSE;
+
+    for (p=0;p<state->common->num_paths;p++)
+        if (!check_path_solution(ret,p)) correct = FALSE;
+
+    for (i=0;i<state->common->num_total;i++)
+        if (!(ret->guess[i] == 1 || ret->guess[i] == 2 ||
+              ret->guess[i] == 4)) correct = FALSE;
+
+    if (correct && !solver) ret->solved = TRUE;
+    if (solver) ret->cheated = TRUE;
+
+    return ret;
+}
+
+/* ----------------------------------------------------------------------
+ * Drawing routines.
+ */
+
+#define PREFERRED_TILE_SIZE 64
+
+static void game_compute_size(game_params *params, int tilesize,
+                              int *x, int *y) {
+    *x = tilesize + (2 + params->w) * tilesize;
+    *y = tilesize + (3 + params->h) * tilesize;
+    return;
+}
+
+static void game_set_size(drawing *dr, game_drawstate *ds,
+                          game_params *params, int tilesize) {
+    ds->tilesize = tilesize;
+    return;
+}
+
+#define COLOUR(ret, i, r, g, b)     ((ret[3*(i)+0] = (r)), (ret[3*(i)+1] = (g)), (ret[3*(i)+2] = (b)))
+
+static float *game_colours(frontend *fe, int *ncolours) {
+    float *ret = snewn(3 * NCOLOURS, float);
+
+    frontend_default_colour(fe, &ret[COL_BACKGROUND * 3]);
+
+    ret[COL_GRID * 3 + 0] = 0.0F;
+    ret[COL_GRID * 3 + 1] = 0.0F;
+    ret[COL_GRID * 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;
+
+    ret[COL_ERROR * 3 + 0] = 1.0F;
+    ret[COL_ERROR * 3 + 1] = 0.0F;
+    ret[COL_ERROR * 3 + 2] = 0.0F;
+
+    ret[COL_HIGHLIGHT * 3 + 0] = 0.78F * ret[COL_BACKGROUND * 3 + 0];
+    ret[COL_HIGHLIGHT * 3 + 1] = 0.78F * ret[COL_BACKGROUND * 3 + 1];
+    ret[COL_HIGHLIGHT * 3 + 2] = 0.78F * ret[COL_BACKGROUND * 3 + 2];
+
+    ret[COL_FLASH * 3 + 0] = 1.0F;
+    ret[COL_FLASH * 3 + 1] = 1.0F;
+    ret[COL_FLASH * 3 + 2] = 1.0F;
+
+    ret[COL_GHOST * 3 + 0] = ret[COL_BACKGROUND * 3 + 0] * 0.5F;
+    ret[COL_GHOST * 3 + 1] = ret[COL_BACKGROUND * 3 + 0];
+    ret[COL_GHOST * 3 + 2] = ret[COL_BACKGROUND * 3 + 0];
+
+    ret[COL_ZOMBIE * 3 + 0] = ret[COL_BACKGROUND * 3 + 0] * 0.5F;
+    ret[COL_ZOMBIE * 3 + 1] = ret[COL_BACKGROUND * 3 + 0];
+    ret[COL_ZOMBIE * 3 + 2] = ret[COL_BACKGROUND * 3 + 0] * 0.5F;
+
+    ret[COL_VAMPIRE * 3 + 0] = ret[COL_BACKGROUND * 3 + 0];
+    ret[COL_VAMPIRE * 3 + 1] = ret[COL_BACKGROUND * 3 + 0] * 0.9F;
+    ret[COL_VAMPIRE * 3 + 2] = ret[COL_BACKGROUND * 3 + 0] * 0.9F;
+
+    *ncolours = NCOLOURS;
+    return ret;
+}
+
+static game_drawstate *game_new_drawstate(drawing *dr, game_state *state) {
+    int i;
+    struct game_drawstate *ds = snew(struct game_drawstate);
+
+    ds->tilesize = 0;
+    ds->started = ds->solved = FALSE;
+    ds->w = state->common->params.w;
+    ds->h = state->common->params.h;
+    ds->ascii = FALSE;
+    
+    ds->count_errors[0] = FALSE;
+    ds->count_errors[1] = FALSE;
+    ds->count_errors[2] = FALSE;
+
+    ds->monsters = snewn(state->common->num_total,int);
+    for (i=0;i<(state->common->num_total);i++)
+        ds->monsters[i] = 7;
+    ds->pencils = snewn(state->common->num_total,unsigned char);
+    for (i=0;i<state->common->num_total;i++)
+        ds->pencils[i] = 0;
+
+    ds->cell_errors = snewn(state->common->wh,unsigned char);
+    for (i=0;i<state->common->wh;i++)
+        ds->cell_errors[i] = FALSE;
+    ds->hint_errors = snewn(2*state->common->num_paths,unsigned char);
+    for (i=0;i<2*state->common->num_paths;i++)
+        ds->hint_errors[i] = FALSE;
+
+    ds->hshow = ds->hpencil = ds->hflash = 0;
+    ds->hx = ds->hy = 0;
+    return ds;
+}
+
+static void game_free_drawstate(drawing *dr, game_drawstate *ds) {
+    sfree(ds->hint_errors);
+    sfree(ds->cell_errors);
+    sfree(ds->pencils);
+    sfree(ds->monsters);
+    sfree(ds);
+    return;
+}
+
+static void draw_cell_background(drawing *dr, game_drawstate *ds,
+                                 game_state *state, game_ui *ui, int x, int y) {
+
+    int hon;
+    int dx,dy;
+    dx = BORDER+(x* ds->tilesize)+(TILESIZE/2);
+    dy = BORDER+(y* ds->tilesize)+(TILESIZE/2)+TILESIZE;
+
+    hon = (ui->hshow && x == ui->hx && y == ui->hy);
+    draw_rect(dr,dx-(TILESIZE/2)+1,dy-(TILESIZE/2)+1,TILESIZE-1,TILESIZE-1,(hon && !ui->hpencil) ? COL_HIGHLIGHT : COL_BACKGROUND);
+
+    if (hon && ui->hpencil) {
+        int coords[6];
+        coords[0] = dx-(TILESIZE/2)+1;
+        coords[1] = dy-(TILESIZE/2)+1;
+        coords[2] = coords[0] + TILESIZE/2;
+        coords[3] = coords[1];
+        coords[4] = coords[0];
+        coords[5] = coords[1] + TILESIZE/2;
+        draw_polygon(dr, coords, 3, COL_HIGHLIGHT, COL_HIGHLIGHT);
+    }
+
+    draw_update(dr,dx-(TILESIZE/2)+1,dy-(TILESIZE/2)+1,TILESIZE-1,TILESIZE-1);
+
+    return;
+}
+
+static void draw_circle_or_point(drawing *dr, int cx, int cy, int radius,
+                                 int colour)
+{
+    if (radius > 0)
+        draw_circle(dr, cx, cy, radius, colour, colour);
+    else
+        draw_rect(dr, cx, cy, 1, 1, colour);
+}
+
+static void draw_monster(drawing *dr, game_drawstate *ds, int x, int y,
+                         int tilesize, int hflash, int monster)
+{
+    int black = (hflash ? COL_FLASH : COL_TEXT);
+    
+    if (monster == 1) {                /* ghost */
+        int poly[80], i, j;
+
+        clip(dr,x-(tilesize/2)+2,y-(tilesize/2)+2,tilesize-3,tilesize/2+1);
+        draw_circle(dr,x,y,2*tilesize/5, COL_GHOST,black);
+        unclip(dr);
+
+        i = 0;
+        poly[i++] = x - 2*tilesize/5;
+        poly[i++] = y-2;
+        poly[i++] = x - 2*tilesize/5;
+        poly[i++] = y + 2*tilesize/5;
+
+        for (j = 0; j < 3; j++) {
+            int total = (2*tilesize/5) * 2;
+            int before = total * j / 3;
+            int after = total * (j+1) / 3;
+            int mid = (before + after) / 2;
+            poly[i++] = x - 2*tilesize/5 + mid;
+            poly[i++] = y + 2*tilesize/5 - (total / 6);
+            poly[i++] = x - 2*tilesize/5 + after;
+            poly[i++] = y + 2*tilesize/5;
+        }
+
+        poly[i++] = x + 2*tilesize/5;
+        poly[i++] = y-2;
+
+        clip(dr,x-(tilesize/2)+2,y,tilesize-3,tilesize-(tilesize/2)-1);
+        draw_polygon(dr, poly, i/2, COL_GHOST, black);
+        unclip(dr);
+
+        draw_circle(dr,x-tilesize/6,y-tilesize/12,tilesize/10,
+                    COL_BACKGROUND,black);
+        draw_circle(dr,x+tilesize/6,y-tilesize/12,tilesize/10,
+                    COL_BACKGROUND,black);
+        
+        draw_circle_or_point(dr,x-tilesize/6+1+tilesize/48,y-tilesize/12,
+                             tilesize/48,black);
+        draw_circle_or_point(dr,x+tilesize/6+1+tilesize/48,y-tilesize/12,
+                             tilesize/48,black);
+        
+    } else if (monster == 2) {         /* vampire */
+        int poly[80], i;
+
+        clip(dr,x-(tilesize/2)+2,y-(tilesize/2)+2,tilesize-3,tilesize/2);
+        draw_circle(dr,x,y,2*tilesize/5,black,black);
+        unclip(dr);
+
+        clip(dr,x-(tilesize/2)+2,y-(tilesize/2)+2,tilesize/2+1,tilesize/2);
+        draw_circle(dr,x-tilesize/7,y,2*tilesize/5-tilesize/7,
+                    COL_VAMPIRE,black);
+        unclip(dr);
+        clip(dr,x,y-(tilesize/2)+2,tilesize/2+1,tilesize/2);
+        draw_circle(dr,x+tilesize/7,y,2*tilesize/5-tilesize/7,
+                    COL_VAMPIRE,black);
+        unclip(dr);
+
+        clip(dr,x-(tilesize/2)+2,y,tilesize-3,tilesize/2);
+        draw_circle(dr,x,y,2*tilesize/5, COL_VAMPIRE,black);
+        unclip(dr);
+
+        draw_circle(dr, x-tilesize/7, y-tilesize/16, tilesize/16,
+                    COL_BACKGROUND, black);
+        draw_circle(dr, x+tilesize/7, y-tilesize/16, tilesize/16,
+                    COL_BACKGROUND, black);
+        draw_circle_or_point(dr, x-tilesize/7, y-tilesize/16, tilesize/48,
+                             black);
+        draw_circle_or_point(dr, x+tilesize/7, y-tilesize/16, tilesize/48,
+                             black);
+
+        clip(dr, x-(tilesize/2)+2, y+tilesize/8, tilesize-3, tilesize/4);
+
+        i = 0;
+        poly[i++] = x-3*tilesize/16;
+        poly[i++] = y+1*tilesize/8;
+        poly[i++] = x-2*tilesize/16;
+        poly[i++] = y+7*tilesize/24;
+        poly[i++] = x-1*tilesize/16;
+        poly[i++] = y+1*tilesize/8;
+        draw_polygon(dr, poly, i/2, COL_BACKGROUND, black);
+        i = 0;
+        poly[i++] = x+3*tilesize/16;
+        poly[i++] = y+1*tilesize/8;
+        poly[i++] = x+2*tilesize/16;
+        poly[i++] = y+7*tilesize/24;
+        poly[i++] = x+1*tilesize/16;
+        poly[i++] = y+1*tilesize/8;
+        draw_polygon(dr, poly, i/2, COL_BACKGROUND, black);
+
+        draw_circle(dr, x, y-tilesize/5, 2*tilesize/5, COL_VAMPIRE, black);
+        unclip(dr);
+
+    } else if (monster == 4) {         /* zombie */
+        draw_circle(dr,x,y,2*tilesize/5, COL_ZOMBIE,black);
+
+        draw_line(dr,
+                  x-tilesize/7-tilesize/16, y-tilesize/12-tilesize/16,
+                  x-tilesize/7+tilesize/16, y-tilesize/12+tilesize/16,
+                  black);
+        draw_line(dr,
+                  x-tilesize/7+tilesize/16, y-tilesize/12-tilesize/16,
+                  x-tilesize/7-tilesize/16, y-tilesize/12+tilesize/16,
+                  black);
+        draw_line(dr,
+                  x+tilesize/7-tilesize/16, y-tilesize/12-tilesize/16,
+                  x+tilesize/7+tilesize/16, y-tilesize/12+tilesize/16,
+                  black);
+        draw_line(dr,
+                  x+tilesize/7+tilesize/16, y-tilesize/12-tilesize/16,
+                  x+tilesize/7-tilesize/16, y-tilesize/12+tilesize/16,
+                  black);
+
+        clip(dr, x-tilesize/5, y+tilesize/6, 2*tilesize/5+1, tilesize/2);
+        draw_circle(dr, x-tilesize/15, y+tilesize/6, tilesize/12,
+                    COL_BACKGROUND, black);
+        unclip(dr);
+
+        draw_line(dr, x-tilesize/5, y+tilesize/6, x+tilesize/5, y+tilesize/6,
+                  black);
+    }
+
+    draw_update(dr,x-(tilesize/2)+2,y-(tilesize/2)+2,tilesize-3,tilesize-3);
+}
+
+static void draw_monster_count(drawing *dr, game_drawstate *ds,
+                               game_state *state, int c, int hflash) {
+    int dx,dy,dh;
+    char buf[8];
+    char bufm[8];
+    
+    dy = TILESIZE/2;
+    dh = TILESIZE;
+    dx = BORDER+(ds->w+2)*TILESIZE/2+TILESIZE/4;
+    switch (c) {
+        case 0: 
+            sprintf(buf,"%d",state->common->num_ghosts);
+            sprintf(bufm,"G");
+            dx -= 3*TILESIZE/2;
+            break;
+        case 1: 
+            sprintf(buf,"%d",state->common->num_vampires); 
+            sprintf(bufm,"V");
+            break;
+        case 2: 
+            sprintf(buf,"%d",state->common->num_zombies); 
+            sprintf(bufm,"Z");
+            dx += 3*TILESIZE/2;
+            break;
+    }
+
+    if (!ds->ascii) { 
+        draw_rect(dr,dx-2*TILESIZE/3,dy,3*TILESIZE/2,dh,COL_BACKGROUND);
+        draw_monster(dr,ds,dx-TILESIZE/3,dh,2*TILESIZE/3,hflash,1<<c);
+        draw_text(dr,dx,dh,FONT_VARIABLE,dy-1,ALIGN_HLEFT|ALIGN_VCENTRE,
+                  (state->count_errors[c] ? COL_ERROR : hflash ? COL_FLASH : COL_TEXT), buf);
+        draw_update(dr,dx-2*TILESIZE/3,dy,3*TILESIZE/2,dh);
+    }
+    else {
+        draw_rect(dr,dx-2*TILESIZE/3,dy,3*TILESIZE/2,dh,COL_BACKGROUND);
+        draw_text(dr,dx-TILESIZE/3,dh,FONT_VARIABLE,dy-1,
+                  ALIGN_HCENTRE|ALIGN_VCENTRE,
+                  hflash ? COL_FLASH : COL_TEXT, bufm);
+        draw_text(dr,dx,dh,FONT_VARIABLE,dy-1,ALIGN_HLEFT|ALIGN_VCENTRE,
+                  (state->count_errors[c] ? COL_ERROR : hflash ? COL_FLASH : COL_TEXT), buf);        
+        draw_update(dr,dx-2*TILESIZE/3,dy,3*TILESIZE/2,dh);
+    }
+
+    return;
+}
+
+static void draw_path_hint(drawing *dr, game_drawstate *ds, game_state *state,
+                           int i, int hflash, int start) {
+    int dx,dy,x,y;
+    int p,error;
+    char buf[80];
+
+    p = start ? state->common->paths[i].grid_start : state->common->paths[i].grid_end;
+    range2grid(p,state->common->params.w,state->common->params.h,&x,&y);
+    error = ds->hint_errors[p];
+
+    dx = BORDER+(x* ds->tilesize)+(TILESIZE/2);
+    dy = BORDER+(y* ds->tilesize)+(TILESIZE/2)+TILESIZE;
+    sprintf(buf,"%d", start ? state->common->paths[i].sightings_start : state->common->paths[i].sightings_end);
+    draw_rect(dr,dx-(TILESIZE/2)+2,dy-(TILESIZE/2)+2,TILESIZE-3,TILESIZE-3,COL_BACKGROUND);
+    draw_text(dr,dx,dy,FONT_FIXED,TILESIZE/2,ALIGN_HCENTRE|ALIGN_VCENTRE, error ? COL_ERROR : hflash ? COL_FLASH : COL_TEXT,buf);
+    draw_update(dr,dx-(TILESIZE/2)+2,dy-(TILESIZE/2)+2,TILESIZE-3,TILESIZE-3);
+
+    return;
+}
+
+static void draw_mirror(drawing *dr, game_drawstate *ds, game_state *state,
+                        int x, int y, int hflash, int mirror) {
+    int dx,dy,mx1,my1,mx2,my2;
+    dx = BORDER+(x* ds->tilesize)+(TILESIZE/2);
+    dy = BORDER+(y* ds->tilesize)+(TILESIZE/2)+TILESIZE;
+
+    if (mirror == CELL_MIRROR_L) {
+        mx1 = dx-(TILESIZE/4);
+        my1 = dy-(TILESIZE/4);
+        mx2 = dx+(TILESIZE/4);
+        my2 = dy+(TILESIZE/4);
+    }
+    else {
+        mx1 = dx-(TILESIZE/4);
+        my1 = dy+(TILESIZE/4);
+        mx2 = dx+(TILESIZE/4);
+        my2 = dy-(TILESIZE/4);
+    }
+    draw_thick_line(dr,(float)(TILESIZE/16),mx1,my1,mx2,my2,
+                    hflash ? COL_FLASH : COL_TEXT);
+    draw_update(dr,dx-(TILESIZE/2)+1,dy-(TILESIZE/2)+1,TILESIZE-1,TILESIZE-1);
+
+    return;
+}
+
+static void draw_big_monster(drawing *dr, game_drawstate *ds, game_state *state,
+                             int x, int y, int hflash, int monster)
+{
+    int dx,dy;
+    char buf[10];
+    dx = BORDER+(x* ds->tilesize)+(TILESIZE/2);
+    dy = BORDER+(y* ds->tilesize)+(TILESIZE/2)+TILESIZE;
+    if (ds->ascii) {
+        if (monster == 1) sprintf(buf,"G");
+        else if (monster == 2) sprintf(buf,"V");
+        else if (monster == 4) sprintf(buf,"Z");
+        else sprintf(buf," ");
+        draw_text(dr,dx,dy,FONT_FIXED,TILESIZE/2,ALIGN_HCENTRE|ALIGN_VCENTRE,
+                  hflash ? COL_FLASH : COL_TEXT,buf);
+        draw_update(dr,dx-(TILESIZE/2)+2,dy-(TILESIZE/2)+2,TILESIZE-3,
+                    TILESIZE-3);
+    }
+    else {
+        draw_monster(dr, ds, dx, dy, 3*TILESIZE/4, hflash, monster);
+    }
+    return;
+}
+
+static void draw_pencils(drawing *dr, game_drawstate *ds, game_state *state,
+                         int x, int y, int pencil) {
+    int dx, dy;
+        int monsters[4];
+        int i, j, px, py;
+    char buf[10];
+    dx = BORDER+(x* ds->tilesize)+(TILESIZE/4);
+    dy = BORDER+(y* ds->tilesize)+(TILESIZE/4)+TILESIZE;
+
+        for (i = 0, j = 1; j < 8; j *= 2)
+            if (pencil & j)
+                monsters[i++] = j;
+        while (i < 4)
+            monsters[i++] = 0;
+
+        for (py = 0; py < 2; py++)
+            for (px = 0; px < 2; px++)
+                if (monsters[py*2+px]) {
+                    if (!ds->ascii) {
+                        draw_monster(dr, ds,
+                                     dx + TILESIZE/2 * px, dy + TILESIZE/2 * py,
+                                     TILESIZE/2, 0, monsters[py*2+px]);
+                    }
+                    else {
+                        switch (monsters[py*2+px]) {
+                            case 1: sprintf(buf,"G"); break;
+                            case 2: sprintf(buf,"V"); break;
+                            case 4: sprintf(buf,"Z"); break;
+                        }
+                        draw_text(dr,dx + TILESIZE/2 * px,dy + TILESIZE/2 * py,
+                                  FONT_FIXED,TILESIZE/4,ALIGN_HCENTRE|ALIGN_VCENTRE,
+                                  COL_TEXT,buf);
+                    }
+                }
+    draw_update(dr,dx-(TILESIZE/4)+2,dy-(TILESIZE/4)+2,
+                (TILESIZE/2)-3,(TILESIZE/2)-3);
+
+    return;
+}
+
+#define FLASH_TIME 0.7F
+
+static void game_redraw(drawing *dr, game_drawstate *ds, game_state *oldstate,
+            game_state *state, int dir, game_ui *ui,
+            float animtime, float flashtime) {
+    int i,j,x,y,xy;
+    int stale, xi, c, hflash, hchanged;
+
+    hflash = (int)(flashtime * 5 / FLASH_TIME) % 2;
+
+    /* Draw static grid components at startup */    
+    if (!ds->started) { 
+        draw_rect(dr, 0, 0, 2*BORDER+(ds->w+2)*TILESIZE,
+                  2*BORDER+(ds->h+3)*TILESIZE, COL_BACKGROUND);
+        draw_rect(dr, BORDER+TILESIZE-1, BORDER+2*TILESIZE-1,
+                  (ds->w)*TILESIZE +3, (ds->h)*TILESIZE +3, COL_GRID);
+        for (i=0;i<ds->w;i++)
+            for (j=0;j<ds->h;j++)
+                draw_rect(dr, BORDER+(ds->tilesize*(i+1))+1,
+                          BORDER+(ds->tilesize*(j+2))+1, ds->tilesize-1,
+                          ds->tilesize-1, COL_BACKGROUND);
+        draw_update(dr,BORDER+TILESIZE-1,BORDER+2*TILESIZE-1,
+                    (ds->w)*TILESIZE+3, (ds->h)*TILESIZE+3);
+    }
+
+    hchanged = FALSE;
+    if (ds->hx != ui->hx || ds->hy != ui->hy ||
+        ds->hshow != ui->hshow || ds->hpencil != ui->hpencil)
+        hchanged = TRUE;
+
+    /* Draw monster count hints */
+
+    for (i=0;i<3;i++) {
+        stale = FALSE;
+        if (!ds->started) stale = TRUE;
+        if (ds->hflash != hflash) stale = TRUE;
+        if (ds->ascii != ui->ascii) stale = TRUE;
+        if (ds->count_errors[i] != state->count_errors[i]) {
+            stale = TRUE;
+            ds->count_errors[i] = state->count_errors[i];
+        }
+        
+        if (stale) {
+            draw_monster_count(dr, ds, state, i, hflash);
+        }
+    }
+
+    /* Draw path count hints */
+    for (i=0;i<state->common->num_paths;i++) {
+        int p;
+        stale = FALSE;
+
+        if (!ds->started) stale = TRUE;
+        if (ds->hflash != hflash) stale = TRUE;
+        
+        p = state->common->paths[i].grid_start;
+        if (ds->hint_errors[p] != state->hint_errors[p]) {
+            stale = TRUE;
+            ds->hint_errors[p] = state->hint_errors[p];
+        }
+
+        if (stale) {
+            draw_path_hint(dr, ds, state, i, hflash, TRUE);
+        }
+
+        stale = FALSE;
+
+        if (!ds->started) stale = TRUE;
+        if (ds->hflash != hflash) stale = TRUE;
+
+        p = state->common->paths[i].grid_end;
+        if (ds->hint_errors[p] != state->hint_errors[p]) {
+            stale = TRUE;
+            ds->hint_errors[p] = state->hint_errors[p];
+        }
+
+        if (stale) {
+            draw_path_hint(dr, ds, state, i, hflash, FALSE);
+        }
+
+    }
+
+    /* Draw puzzle grid contents */
+    for (x = 1; x < ds->w+1; x++)
+    for (y = 1; y < ds->h+1; y++) {
+        stale = FALSE;
+        xy = x+y*(state->common->params.w+2);
+        xi = state->common->xinfo[xy];
+        c = state->common->grid[xy];
+    
+        if (!ds->started) stale = TRUE;
+        if (ds->hflash != hflash) stale = TRUE;
+        if (ds->ascii != ui->ascii) stale = TRUE;
+        
+        if (hchanged) {
+            if ((x == ui->hx && y == ui->hy) ||
+                (x == ds->hx && y == ds->hy))
+                stale = TRUE;
+        }
+
+        if (xi >= 0 && (state->guess[xi] != ds->monsters[xi]) ) {
+            stale = TRUE;
+            ds->monsters[xi] = state->guess[xi];
+        }
+        
+        if (xi >= 0 && (state->pencils[xi] != ds->pencils[xi]) ) {
+            stale = TRUE;
+            ds->pencils[xi] = state->pencils[xi];
+        }
+
+        if (state->cell_errors[xy] != ds->cell_errors[xy]) {
+            stale = TRUE;
+            ds->cell_errors[xy] = state->cell_errors[xy];
+        }
+                
+        if (stale) {
+            draw_cell_background(dr, ds, state, ui, x, y);
+            if (xi < 0) 
+                draw_mirror(dr, ds, state, x, y, hflash, c);
+            else if (state->guess[xi] == 1 || state->guess[xi] == 2 ||
+                     state->guess[xi] == 4)
+                draw_big_monster(dr, ds, state, x, y, hflash, state->guess[xi]);
+            else 
+                draw_pencils(dr, ds, state, x, y, state->pencils[xi]);
+        }
+    }
+
+    ds->hx = ui->hx; ds->hy = ui->hy;
+    ds->hshow = ui->hshow;
+    ds->hpencil = ui->hpencil;
+    ds->hflash = hflash;
+    ui->ascii = ds->ascii;
+    ds->started = TRUE;
+    return;
+}
+
+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) {
+    return (!oldstate->solved && newstate->solved && !oldstate->cheated &&
+            !newstate->cheated) ? FLASH_TIME : 0.0F;
+}
+
+static int game_status(game_state *state) {
+    return state->solved;
+}
+
+static int game_timing_state(game_state *state, game_ui *ui) {
+    return TRUE;
+}
+
+static void game_print_size(game_params *params, float *x, float *y) {
+}
+
+static void game_print(drawing *dr, game_state *state, int tilesize) {
+}
+
+#ifdef COMBINED
+#define thegame undead
+#endif
+
+const struct game thegame = {
+    "Undead", "games.undead", "undead",
+    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_can_format_as_text_now, game_text_format,
+    new_ui,
+    free_ui,
+    encode_ui,
+    decode_ui,
+    game_changed_state,
+    interpret_move,
+    execute_move,
+    PREFERRED_TILE_SIZE, game_compute_size, game_set_size,
+    game_colours,
+    game_new_drawstate,
+    game_free_drawstate,
+    game_redraw,
+    game_anim_length,
+    game_flash_length,
+    game_status,
+    FALSE, FALSE, game_print_size, game_print,
+    FALSE,                 /* wants_statusbar */
+    FALSE, game_timing_state,
+    0,                     /* flags */
+};
+