hunt/huntd/makemaze.c

   1 /*      $NetBSD: makemaze.c,v 1.3 2003/06/11 12:00:22 wiz Exp $ */
   2 /*
   3  * Copyright (c) 1983-2003, Regents of the University of California.
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are
   8  * met:
   9  *
  10  * + Redistributions of source code must retain the above copyright
  11  *   notice, this list of conditions and the following disclaimer.
  12  * + Redistributions in binary form must reproduce the above copyright
  13  *   notice, this list of conditions and the following disclaimer in the
  14  *   documentation and/or other materials provided with the distribution.
  15  * + Neither the name of the University of California, San Francisco nor
  16  *   the names of its contributors may be used to endorse or promote
  17  *   products derived from this software without specific prior written
  18  *   permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  21  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  23  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  24  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  25  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  26  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  30  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  31  */
  32
  33 #include <sys/cdefs.h>
  34 #ifndef lint
  35 __RCSID("$NetBSD: makemaze.c,v 1.3 2003/06/11 12:00:22 wiz Exp $");
  36 #endif /* not lint */
  37
  38 # include       "hunt.h"
  39
  40 # define        ISCLEAR(y,x)    (Maze[y][x] == SPACE)
  41 # define        ODD(n)          ((n) & 01)
  42
  43 static  int     candig __P((int, int));
  44 static  void    dig __P((int, int));
  45 static  void    dig_maze __P((int, int));
  46 static  void    remap __P((void));
  47
  48 void
  49 makemaze()
  50 {
  51         char    *sp;
  52         int     y, x;
  53
  54         /*
  55          * fill maze with walls
  56          */
  57         sp = &Maze[0][0];
  58         while (sp < &Maze[HEIGHT - 1][WIDTH])
  59                 *sp++ = DOOR;
  60
  61         x = rand_num(WIDTH / 2) * 2 + 1;
  62         y = rand_num(HEIGHT / 2) * 2 + 1;
  63         dig_maze(x, y);
  64         remap();
  65 }
  66
  67 # define        NPERM   24
  68 # define        NDIR    4
  69
  70 int     dirs[NPERM][NDIR] = {
  71                 {0,1,2,3},      {3,0,1,2},      {0,2,3,1},      {0,3,2,1},
  72                 {1,0,2,3},      {2,3,0,1},      {0,2,1,3},      {2,3,1,0},
  73                 {1,0,3,2},      {1,2,0,3},      {3,1,2,0},      {2,0,3,1},
  74                 {1,3,0,2},      {0,3,1,2},      {1,3,2,0},      {2,0,1,3},
  75                 {0,1,3,2},      {3,1,0,2},      {2,1,0,3},      {1,2,3,0},
  76                 {2,1,3,0},      {3,0,2,1},      {3,2,0,1},      {3,2,1,0}
  77         };
  78
  79 int     incr[NDIR][2] = {
  80                 {0, 1}, {1, 0}, {0, -1}, {-1, 0}
  81         };
  82
  83 static void
  84 dig(y, x)
  85         int     y, x;
  86 {
  87         int     *dp;
  88         int     *ip;
  89         int     ny, nx;
  90         int     *endp;
  91
  92         Maze[y][x] = SPACE;                     /* Clear this spot */
  93         dp = dirs[rand_num(NPERM)];
  94         endp = &dp[NDIR];
  95         while (dp < endp) {
  96                 ip = &incr[*dp++][0];
  97                 ny = y + *ip++;
  98                 nx = x + *ip;
  99                 if (candig(ny, nx))
 100                         dig(ny, nx);
 101         }
 102 }
 103
 104 /*
 105  * candig:
 106  *      Is it legal to clear this spot?
 107  */
 108 static int
 109 candig(y, x)
 110         int     y, x;
 111 {
 112         int     i;
 113
 114         if (ODD(x) && ODD(y))
 115                 return FALSE;           /* can't touch ODD spots */
 116
 117         if (y < UBOUND || y >= DBOUND)
 118                 return FALSE;           /* Beyond vertical bounds, NO */
 119         if (x < LBOUND || x >= RBOUND)
 120                 return FALSE;           /* Beyond horizontal bounds, NO */
 121
 122         if (ISCLEAR(y, x))
 123                 return FALSE;           /* Already clear, NO */
 124
 125         i = ISCLEAR(y, x + 1);
 126         i += ISCLEAR(y, x - 1);
 127         if (i > 1)
 128                 return FALSE;           /* Introduces cycle, NO */
 129         i += ISCLEAR(y + 1, x);
 130         if (i > 1)
 131                 return FALSE;           /* Introduces cycle, NO */
 132         i += ISCLEAR(y - 1, x);
 133         if (i > 1)
 134                 return FALSE;           /* Introduces cycle, NO */
 135
 136         return TRUE;                    /* OK */
 137 }
 138
 139 void
 140 dig_maze(x, y)
 141         int     x, y;
 142 {
 143         int     tx, ty;
 144         int     i, j;
 145         int     order[4];
 146 #define MNORTH  0x1
 147 #define MSOUTH  0x2
 148 #define MEAST   0x4
 149 #define MWEST   0x8
 150
 151         tx = ty = 0;
 152         Maze[y][x] = SPACE;
 153         order[0] = MNORTH;
 154         for (i = 1; i < 4; i++) {
 155                 j = rand_num(i + 1);
 156                 order[i] = order[j];
 157                 order[j] = 0x1 << i;
 158         }
 159         for (i = 0; i < 4; i++) {
 160                 switch (order[i]) {
 161                   case MNORTH:
 162                         tx = x;
 163                         ty = y - 2;
 164                         break;
 165                   case MSOUTH:
 166                         tx = x;
 167                         ty = y + 2;
 168                         break;
 169                   case MEAST:
 170                         tx = x + 2;
 171                         ty = y;
 172                         break;
 173                   case MWEST:
 174                         tx = x - 2;
 175                         ty = y;
 176                         break;
 177                 }
 178                 if (tx < 0 || ty < 0 || tx >= WIDTH || ty >= HEIGHT)
 179                         continue;
 180                 if (Maze[ty][tx] == SPACE)
 181                         continue;
 182                 Maze[(y + ty) / 2][(x + tx) / 2] = SPACE;
 183                 dig_maze(tx, ty);
 184         }
 185 }
 186
 187 void
 188 remap()
 189 {
 190         int     y, x;
 191         char    *sp;
 192         int     stat;
 193
 194         for (y = 0; y < HEIGHT; y++)
 195                 for (x = 0; x < WIDTH; x++) {
 196                         sp = &Maze[y][x];
 197                         if (*sp == SPACE)
 198                                 continue;
 199                         stat = 0;
 200                         if (y - 1 >= 0 && Maze[y - 1][x] != SPACE)
 201                                 stat |= NORTH;
 202                         if (y + 1 < HEIGHT && Maze[y + 1][x] != SPACE)
 203                                 stat |= SOUTH;
 204                         if (x + 1 < WIDTH && Maze[y][x + 1] != SPACE)
 205                                 stat |= EAST;
 206                         if (x - 1 >= 0 && Maze[y][x - 1] != SPACE)
 207                                 stat |= WEST;
 208                         switch (stat) {
 209                           case WEST | EAST:
 210                           case EAST:
 211                           case WEST:
 212                                 *sp = WALL1;
 213                                 break;
 214                           case NORTH | SOUTH:
 215                           case NORTH:
 216                           case SOUTH:
 217                                 *sp = WALL2;
 218                                 break;
 219                           case 0:
 220 # ifdef RANDOM
 221                                 *sp = DOOR;
 222 # endif
 223 # ifdef REFLECT
 224                                 *sp = rand_num(2) ? WALL4 : WALL5;
 225 # endif
 226                                 break;
 227                           default:
 228                                 *sp = WALL3;
 229                                 break;
 230                         }
 231                 }
 232         memcpy(Orig_maze, Maze, sizeof Maze);
 233 }