1 /* $OpenBSD: makemaze.c,v 1.6 2003/06/11 08:45:33 pjanzen Exp $ */ 2 /* $NetBSD: makemaze.c,v 1.2 1997/10/10 16:33:43 lukem Exp $ */ 3 /* 4 * Copyright (c) 1983-2003, Regents of the University of California. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions are 9 * met: 10 * 11 * + Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * + Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * + Neither the name of the University of California, San Francisco nor 17 * the names of its contributors may be used to endorse or promote 18 * products derived from this software without specific prior written 19 * permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS 22 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 23 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 24 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 25 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 27 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 31 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #include <string.h> 35 36 #include "hunt.h" 37 #include "server.h" 38 #include "conf.h" 39 40 # define ISCLEAR(y,x) (Maze[y][x] == SPACE) 41 # define ODD(n) ((n) & 01) 42 43 static int candig(int, int); 44 static void dig(int, int); 45 static void dig_maze(int, int); 46 static void remap(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 static 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 static 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 /* Find occupied adjacent cells. */ 200 stat = 0; 201 if (y - 1 >= 0 && Maze[y - 1][x] != SPACE) 202 stat |= NORTH; 203 if (y + 1 < HEIGHT && Maze[y + 1][x] != SPACE) 204 stat |= SOUTH; 205 if (x + 1 < WIDTH && Maze[y][x + 1] != SPACE) 206 stat |= EAST; 207 if (x - 1 >= 0 && Maze[y][x - 1] != SPACE) 208 stat |= WEST; 209 switch (stat) { 210 case WEST | EAST: 211 case EAST: 212 case WEST: 213 *sp = WALL1; /* - */ 214 break; 215 case NORTH | SOUTH: 216 case NORTH: 217 case SOUTH: 218 *sp = WALL2; /* | */ 219 break; 220 case 0: 221 if (conf_random) 222 *sp = DOOR; 223 if (conf_reflect) 224 *sp = rand_num(2) ? WALL4 : WALL5; 225 break; 226 default: 227 *sp = WALL3; /* + */ 228 break; 229 } 230 } 231 memcpy(Orig_maze, Maze, sizeof Orig_maze); 232 } 233