1 /* $OpenBSD: makemaze.c,v 1.10 2017/01/21 08:22:57 krw 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 <sys/select.h>
35 #include <string.h>
36
37 #include "conf.h"
38 #include "hunt.h"
39 #include "server.h"
40
41 # define ISCLEAR(y,x) (Maze[y][x] == SPACE)
42 # define ODD(n) ((n) & 01)
43
44 static int candig(int, int);
45 static void dig(int, int);
46 static void dig_maze(int, int);
47 static void remap(void);
48
49 void
makemaze(void)50 makemaze(void)
51 {
52 char *sp;
53 int y, x;
54
55 /*
56 * fill maze with walls
57 */
58 sp = &Maze[0][0];
59 while (sp < &Maze[HEIGHT - 1][WIDTH])
60 *sp++ = DOOR;
61
62 x = rand_num(WIDTH / 2) * 2 + 1;
63 y = rand_num(HEIGHT / 2) * 2 + 1;
64 dig_maze(x, y);
65 remap();
66 }
67
68 # define NPERM 24
69 # define NDIR 4
70
71 int dirs[NPERM][NDIR] = {
72 {0,1,2,3}, {3,0,1,2}, {0,2,3,1}, {0,3,2,1},
73 {1,0,2,3}, {2,3,0,1}, {0,2,1,3}, {2,3,1,0},
74 {1,0,3,2}, {1,2,0,3}, {3,1,2,0}, {2,0,3,1},
75 {1,3,0,2}, {0,3,1,2}, {1,3,2,0}, {2,0,1,3},
76 {0,1,3,2}, {3,1,0,2}, {2,1,0,3}, {1,2,3,0},
77 {2,1,3,0}, {3,0,2,1}, {3,2,0,1}, {3,2,1,0}
78 };
79
80 int incr[NDIR][2] = {
81 {0, 1}, {1, 0}, {0, -1}, {-1, 0}
82 };
83
84 static void
dig(int y,int x)85 dig(int y, int 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
candig(int y,int x)109 candig(int y, int x)
110 {
111 int i;
112
113 if (ODD(x) && ODD(y))
114 return FALSE; /* can't touch ODD spots */
115
116 if (y < UBOUND || y >= DBOUND)
117 return FALSE; /* Beyond vertical bounds, NO */
118 if (x < LBOUND || x >= RBOUND)
119 return FALSE; /* Beyond horizontal bounds, NO */
120
121 if (ISCLEAR(y, x))
122 return FALSE; /* Already clear, NO */
123
124 i = ISCLEAR(y, x + 1);
125 i += ISCLEAR(y, x - 1);
126 if (i > 1)
127 return FALSE; /* Introduces cycle, NO */
128 i += ISCLEAR(y + 1, x);
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
135 return TRUE; /* OK */
136 }
137
138 static void
dig_maze(int x,int y)139 dig_maze(int x, int y)
140 {
141 int tx, ty;
142 int i, j;
143 int order[4];
144 #define MNORTH 0x1
145 #define MSOUTH 0x2
146 #define MEAST 0x4
147 #define MWEST 0x8
148
149 tx = ty = 0;
150 Maze[y][x] = SPACE;
151 order[0] = MNORTH;
152 for (i = 1; i < 4; i++) {
153 j = rand_num(i + 1);
154 order[i] = order[j];
155 order[j] = 0x1 << i;
156 }
157 for (i = 0; i < 4; i++) {
158 switch (order[i]) {
159 case MNORTH:
160 tx = x;
161 ty = y - 2;
162 break;
163 case MSOUTH:
164 tx = x;
165 ty = y + 2;
166 break;
167 case MEAST:
168 tx = x + 2;
169 ty = y;
170 break;
171 case MWEST:
172 tx = x - 2;
173 ty = y;
174 break;
175 }
176 if (tx < 0 || ty < 0 || tx >= WIDTH || ty >= HEIGHT)
177 continue;
178 if (Maze[ty][tx] == SPACE)
179 continue;
180 Maze[(y + ty) / 2][(x + tx) / 2] = SPACE;
181 dig_maze(tx, ty);
182 }
183 }
184
185 static void
remap(void)186 remap(void)
187 {
188 int y, x;
189 char *sp;
190 int stat;
191
192 for (y = 0; y < HEIGHT; y++)
193 for (x = 0; x < WIDTH; x++) {
194 sp = &Maze[y][x];
195 if (*sp == SPACE)
196 continue;
197 /* Find occupied adjacent cells. */
198 stat = 0;
199 if (y - 1 >= 0 && Maze[y - 1][x] != SPACE)
200 stat |= NORTH;
201 if (y + 1 < HEIGHT && Maze[y + 1][x] != SPACE)
202 stat |= SOUTH;
203 if (x + 1 < WIDTH && Maze[y][x + 1] != SPACE)
204 stat |= EAST;
205 if (x - 1 >= 0 && Maze[y][x - 1] != SPACE)
206 stat |= WEST;
207 switch (stat) {
208 case WEST | EAST:
209 case EAST:
210 case WEST:
211 *sp = WALL1; /* - */
212 break;
213 case NORTH | SOUTH:
214 case NORTH:
215 case SOUTH:
216 *sp = WALL2; /* | */
217 break;
218 case 0:
219 if (conf_random)
220 *sp = DOOR;
221 if (conf_reflect)
222 *sp = rand_num(2) ? WALL4 : WALL5;
223 break;
224 default:
225 *sp = WALL3; /* + */
226 break;
227 }
228 }
229 memcpy(Orig_maze, Maze, sizeof Orig_maze);
230 }
231