makemaze.c revision 1.6
1 /* $NetBSD: makemaze.c,v 1.6 2009/07/04 04:29:55 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 1.6 2009/07/04 04:29:55 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 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(void) 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(int y, int x) 85 { 86 int *dp; 87 int *ip; 88 int ny, nx; 89 int *endp; 90 91 Maze[y][x] = SPACE; /* Clear this spot */ 92 dp = dirs[rand_num(NPERM)]; 93 endp = &dp[NDIR]; 94 while (dp < endp) { 95 ip = &incr[*dp++][0]; 96 ny = y + *ip++; 97 nx = x + *ip; 98 if (candig(ny, nx)) 99 dig(ny, nx); 100 } 101 } 102 103 /* 104 * candig: 105 * Is it legal to clear this spot? 106 */ 107 static int 108 candig(int y, int x) 109 { 110 int i; 111 112 if (ODD(x) && ODD(y)) 113 return FALSE; /* can't touch ODD spots */ 114 115 if (y < UBOUND || y >= DBOUND) 116 return FALSE; /* Beyond vertical bounds, NO */ 117 if (x < LBOUND || x >= RBOUND) 118 return FALSE; /* Beyond horizontal bounds, NO */ 119 120 if (ISCLEAR(y, x)) 121 return FALSE; /* Already clear, NO */ 122 123 i = ISCLEAR(y, x + 1); 124 i += ISCLEAR(y, x - 1); 125 if (i > 1) 126 return FALSE; /* Introduces cycle, NO */ 127 i += ISCLEAR(y + 1, x); 128 if (i > 1) 129 return FALSE; /* Introduces cycle, NO */ 130 i += ISCLEAR(y - 1, x); 131 if (i > 1) 132 return FALSE; /* Introduces cycle, NO */ 133 134 return TRUE; /* OK */ 135 } 136 137 void 138 dig_maze(int x, int y) 139 { 140 int tx, ty; 141 int i, j; 142 int order[4]; 143 #define MNORTH 0x1 144 #define MSOUTH 0x2 145 #define MEAST 0x4 146 #define MWEST 0x8 147 148 tx = ty = 0; 149 Maze[y][x] = SPACE; 150 order[0] = MNORTH; 151 for (i = 1; i < 4; i++) { 152 j = rand_num(i + 1); 153 order[i] = order[j]; 154 order[j] = 0x1 << i; 155 } 156 for (i = 0; i < 4; i++) { 157 switch (order[i]) { 158 case MNORTH: 159 tx = x; 160 ty = y - 2; 161 break; 162 case MSOUTH: 163 tx = x; 164 ty = y + 2; 165 break; 166 case MEAST: 167 tx = x + 2; 168 ty = y; 169 break; 170 case MWEST: 171 tx = x - 2; 172 ty = y; 173 break; 174 } 175 if (tx < 0 || ty < 0 || tx >= WIDTH || ty >= HEIGHT) 176 continue; 177 if (Maze[ty][tx] == SPACE) 178 continue; 179 Maze[(y + ty) / 2][(x + tx) / 2] = SPACE; 180 dig_maze(tx, ty); 181 } 182 } 183 184 void 185 remap(void) 186 { 187 int y, x; 188 char *sp; 189 int stat; 190 191 for (y = 0; y < HEIGHT; y++) 192 for (x = 0; x < WIDTH; x++) { 193 sp = &Maze[y][x]; 194 if (*sp == SPACE) 195 continue; 196 stat = 0; 197 if (y - 1 >= 0 && Maze[y - 1][x] != SPACE) 198 stat |= NORTH; 199 if (y + 1 < HEIGHT && Maze[y + 1][x] != SPACE) 200 stat |= SOUTH; 201 if (x + 1 < WIDTH && Maze[y][x + 1] != SPACE) 202 stat |= EAST; 203 if (x - 1 >= 0 && Maze[y][x - 1] != SPACE) 204 stat |= WEST; 205 switch (stat) { 206 case WEST | EAST: 207 case EAST: 208 case WEST: 209 *sp = WALL1; 210 break; 211 case NORTH | SOUTH: 212 case NORTH: 213 case SOUTH: 214 *sp = WALL2; 215 break; 216 case 0: 217 #ifdef RANDOM 218 *sp = DOOR; 219 #endif 220 #ifdef REFLECT 221 *sp = rand_num(2) ? WALL4 : WALL5; 222 #endif 223 break; 224 default: 225 *sp = WALL3; 226 break; 227 } 228 } 229 memcpy(Orig_maze, Maze, sizeof Maze); 230 } 231
Indexes created Fri Oct 03 02:09:57 GMT 2025