hunt/huntd/makemaze.c

   1 /*      $NetBSD: makemaze.c,v 1.9 2014/03/29 19:41:11 dholland 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 1.9 2014/03/29 19:41:11 dholland 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 #if 0
  44 static bool candig(int, int);
  45 static void dig(int, int);
  46 #endif
  47 static void dig_maze(int, int);
  48 static void remap(void);
  49
  50 void
  51 makemaze(void)
  52 {
  53         char *sp;
  54         int y, x;
  55
  56         /*
  57          * fill maze with walls
  58          */
  59         sp = &Maze[0][0];
  60         while (sp < &Maze[HEIGHT - 1][WIDTH])
  61                 *sp++ = DOOR;
  62
  63         x = rand_num(WIDTH / 2) * 2 + 1;
  64         y = rand_num(HEIGHT / 2) * 2 + 1;
  65         dig_maze(x, y);
  66         remap();
  67 }
  68
  69 #define NPERM   24
  70 #define NDIR    4
  71
  72 #if 0
  73 static int dirs[NPERM][NDIR] = {
  74         {0,1,2,3},      {3,0,1,2},      {0,2,3,1},      {0,3,2,1},
  75         {1,0,2,3},      {2,3,0,1},      {0,2,1,3},      {2,3,1,0},
  76         {1,0,3,2},      {1,2,0,3},      {3,1,2,0},      {2,0,3,1},
  77         {1,3,0,2},      {0,3,1,2},      {1,3,2,0},      {2,0,1,3},
  78         {0,1,3,2},      {3,1,0,2},      {2,1,0,3},      {1,2,3,0},
  79         {2,1,3,0},      {3,0,2,1},      {3,2,0,1},      {3,2,1,0}
  80 };
  81
  82 static int incr[NDIR][2] = {
  83         {0, 1}, {1, 0}, {0, -1}, {-1, 0}
  84 };
  85
  86
  87 static void
  88 dig(int y, int x)
  89 {
  90         int *dp;
  91         int *ip;
  92         int ny, nx;
  93         int *endp;
  94
  95         Maze[y][x] = SPACE;                     /* Clear this spot */
  96         dp = dirs[rand_num(NPERM)];
  97         endp = &dp[NDIR];
  98         while (dp < endp) {
  99                 ip = &incr[*dp++][0];
 100                 ny = y + *ip++;
 101                 nx = x + *ip;
 102                 if (candig(ny, nx))
 103                         dig(ny, nx);
 104         }
 105 }
 106
 107 /*
 108  * candig:
 109  *      Is it legal to clear this spot?
 110  */
 111 static bool
 112 candig(int y, int x)
 113 {
 114         int i;
 115
 116         if (ODD(x) && ODD(y))
 117                 return false;           /* can't touch ODD spots */
 118
 119         if (y < UBOUND || y >= DBOUND)
 120                 return false;           /* Beyond vertical bounds, NO */
 121         if (x < LBOUND || x >= RBOUND)
 122                 return false;           /* Beyond horizontal bounds, NO */
 123
 124         if (ISCLEAR(y, x))
 125                 return false;           /* Already clear, NO */
 126
 127         i = ISCLEAR(y, x + 1);
 128         i += ISCLEAR(y, x - 1);
 129         if (i > 1)
 130                 return false;           /* Introduces cycle, NO */
 131         i += ISCLEAR(y + 1, x);
 132         if (i > 1)
 133                 return false;           /* Introduces cycle, NO */
 134         i += ISCLEAR(y - 1, x);
 135         if (i > 1)
 136                 return false;           /* Introduces cycle, NO */
 137
 138         return true;                    /* OK */
 139 }
 140 #endif
 141
 142 void
 143 dig_maze(int x, int y)
 144 {
 145         int tx, ty;
 146         int i, j;
 147         int order[4];
 148 #define MNORTH  0x1
 149 #define MSOUTH  0x2
 150 #define MEAST   0x4
 151 #define MWEST   0x8
 152
 153         tx = ty = 0;
 154         Maze[y][x] = SPACE;
 155         order[0] = MNORTH;
 156         for (i = 1; i < 4; i++) {
 157                 j = rand_num(i + 1);
 158                 order[i] = order[j];
 159                 order[j] = 0x1 << i;
 160         }
 161         for (i = 0; i < 4; i++) {
 162                 switch (order[i]) {
 163                   case MNORTH:
 164                         tx = x;
 165                         ty = y - 2;
 166                         break;
 167                   case MSOUTH:
 168                         tx = x;
 169                         ty = y + 2;
 170                         break;
 171                   case MEAST:
 172                         tx = x + 2;
 173                         ty = y;
 174                         break;
 175                   case MWEST:
 176                         tx = x - 2;
 177                         ty = y;
 178                         break;
 179                 }
 180                 if (tx < 0 || ty < 0 || tx >= WIDTH || ty >= HEIGHT)
 181                         continue;
 182                 if (Maze[ty][tx] == SPACE)
 183                         continue;
 184                 Maze[(y + ty) / 2][(x + tx) / 2] = SPACE;
 185                 dig_maze(tx, ty);
 186         }
 187 }
 188
 189 void
 190 remap(void)
 191 {
 192         int y, x;
 193         char *sp;
 194         int stat;
 195
 196         for (y = 0; y < HEIGHT; y++)
 197                 for (x = 0; x < WIDTH; x++) {
 198                         sp = &Maze[y][x];
 199                         if (*sp == SPACE)
 200                                 continue;
 201                         stat = 0;
 202                         if (y - 1 >= 0 && Maze[y - 1][x] != SPACE)
 203                                 stat |= NORTH;
 204                         if (y + 1 < HEIGHT && Maze[y + 1][x] != SPACE)
 205                                 stat |= SOUTH;
 206                         if (x + 1 < WIDTH && Maze[y][x + 1] != SPACE)
 207                                 stat |= EAST;
 208                         if (x - 1 >= 0 && Maze[y][x - 1] != SPACE)
 209                                 stat |= WEST;
 210                         switch (stat) {
 211                           case WEST | EAST:
 212                           case EAST:
 213                           case WEST:
 214                                 *sp = WALL1;
 215                                 break;
 216                           case NORTH | SOUTH:
 217                           case NORTH:
 218                           case SOUTH:
 219                                 *sp = WALL2;
 220                                 break;
 221                           case 0:
 222 #ifdef RANDOM
 223                                 *sp = DOOR;
 224 #endif
 225 #ifdef REFLECT
 226                                 *sp = rand_num(2) ? WALL4 : WALL5;
 227 #endif
 228                                 break;
 229                           default:
 230                                 *sp = WALL3;
 231                                 break;
 232                         }
 233                 }
 234         memcpy(Orig_maze, Maze, sizeof Maze);
 235 }