games/hunt/huntd/makemaze.c

   1 /*
   2  * Copyright (c) 1983-2003, Regents of the University of California.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met:
   8  *
   9  * + Redistributions of source code must retain the above copyright
  10  *   notice, this list of conditions and the following disclaimer.
  11  * + Redistributions in binary form must reproduce the above copyright
  12  *   notice, this list of conditions and the following disclaimer in the
  13  *   documentation and/or other materials provided with the distribution.
  14  * + Neither the name of the University of California, San Francisco nor
  15  *   the names of its contributors may be used to endorse or promote
  16  *   products derived from this software without specific prior written
  17  *   permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  20  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  22  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  23  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  29  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  *
  31  * $OpenBSD: makemaze.c,v 1.6 2003/06/11 08:45:33 pjanzen Exp $
  32  * $NetBSD: makemaze.c,v 1.2 1997/10/10 16:33:43 lukem Exp $
  33  * $DragonFly: src/games/hunt/huntd/makemaze.c,v 1.2 2008/09/04 16:12:51 swildner Exp $
  34  */
  35
  36 #include <string.h>
  37
  38 #include "hunt.h"
  39 #include "server.h"
  40 #include "conf.h"
  41
  42 # define        ISCLEAR(y,x)    (Maze[y][x] == SPACE)
  43 # define        ODD(n)          ((n) & 01)
  44
  45 static  int     candig(int, int);
  46 static  void    dig(int, int);
  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 int     dirs[NPERM][NDIR] = {
  73                 {0,1,2,3},      {3,0,1,2},      {0,2,3,1},      {0,3,2,1},
  74                 {1,0,2,3},      {2,3,0,1},      {0,2,1,3},      {2,3,1,0},
  75                 {1,0,3,2},      {1,2,0,3},      {3,1,2,0},      {2,0,3,1},
  76                 {1,3,0,2},      {0,3,1,2},      {1,3,2,0},      {2,0,1,3},
  77                 {0,1,3,2},      {3,1,0,2},      {2,1,0,3},      {1,2,3,0},
  78                 {2,1,3,0},      {3,0,2,1},      {3,2,0,1},      {3,2,1,0}
  79         };
  80
  81 int     incr[NDIR][2] = {
  82                 {0, 1}, {1, 0}, {0, -1}, {-1, 0}
  83         };
  84
  85 static void
  86 dig(int y, int x)
  87 {
  88         int     *dp;
  89         int     *ip;
  90         int     ny, nx;
  91         int     *endp;
  92
  93         Maze[y][x] = SPACE;                     /* Clear this spot */
  94         dp = dirs[rand_num(NPERM)];
  95         endp = &dp[NDIR];
  96         while (dp < endp) {
  97                 ip = &incr[*dp++][0];
  98                 ny = y + *ip++;
  99                 nx = x + *ip;
 100                 if (candig(ny, nx))
 101                         dig(ny, nx);
 102         }
 103 }
 104
 105 /*
 106  * candig:
 107  *      Is it legal to clear this spot?
 108  */
 109 static int
 110 candig(int y, int 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 static void
 140 dig_maze(int x, int y)
 141 {
 142         int     tx, ty;
 143         int     i, j;
 144         int     order[4];
 145 #define MNORTH  0x1
 146 #define MSOUTH  0x2
 147 #define MEAST   0x4
 148 #define MWEST   0x8
 149
 150         tx = ty = 0;
 151         Maze[y][x] = SPACE;
 152         order[0] = MNORTH;
 153         for (i = 1; i < 4; i++) {
 154                 j = rand_num(i + 1);
 155                 order[i] = order[j];
 156                 order[j] = 0x1 << i;
 157         }
 158         for (i = 0; i < 4; i++) {
 159                 switch (order[i]) {
 160                   case MNORTH:
 161                         tx = x;
 162                         ty = y - 2;
 163                         break;
 164                   case MSOUTH:
 165                         tx = x;
 166                         ty = y + 2;
 167                         break;
 168                   case MEAST:
 169                         tx = x + 2;
 170                         ty = y;
 171                         break;
 172                   case MWEST:
 173                         tx = x - 2;
 174                         ty = y;
 175                         break;
 176                 }
 177                 if (tx < 0 || ty < 0 || tx >= WIDTH || ty >= HEIGHT)
 178                         continue;
 179                 if (Maze[ty][tx] == SPACE)
 180                         continue;
 181                 Maze[(y + ty) / 2][(x + tx) / 2] = SPACE;
 182                 dig_maze(tx, ty);
 183         }
 184 }
 185
 186 static void
 187 remap(void)
 188 {
 189         int     y, x;
 190         char    *sp;
 191         int     stat;
 192
 193         for (y = 0; y < HEIGHT; y++)
 194                 for (x = 0; x < WIDTH; x++) {
 195                         sp = &Maze[y][x];
 196                         if (*sp == SPACE)
 197                                 continue;
 198                         /* Find occupied adjacent cells. */
 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                                 if (conf_random)
 221                                         *sp = DOOR;
 222                                 if (conf_reflect)
 223                                         *sp = rand_num(2) ? WALL4 : WALL5;
 224                                 break;
 225                           default:
 226                                 *sp = WALL3;                       /* + */
 227                                 break;
 228                         }
 229                 }
 230         memcpy(Orig_maze, Maze, sizeof Orig_maze);
 231 }