xref: /netbsd/games/hack/hack.mklev.c (revision fe7fbef8)
1 /*	$NetBSD: hack.mklev.c,v 1.9 2011/08/06 20:42:43 dholland Exp $	*/
2 
3 /*
4  * Copyright (c) 1985, Stichting Centrum voor Wiskunde en Informatica,
5  * Amsterdam
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions are
10  * met:
11  *
12  * - Redistributions of source code must retain the above copyright notice,
13  * this list of conditions and the following disclaimer.
14  *
15  * - Redistributions in binary form must reproduce the above copyright
16  * notice, this list of conditions and the following disclaimer in the
17  * documentation and/or other materials provided with the distribution.
18  *
19  * - Neither the name of the Stichting Centrum voor Wiskunde en
20  * Informatica, nor the names of its contributors may be used to endorse or
21  * promote products derived from this software without specific prior
22  * written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
25  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
26  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
27  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
28  * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
29  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
30  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
31  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
32  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
33  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
34  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35  */
36 
37 /*
38  * Copyright (c) 1982 Jay Fenlason <hack@gnu.org>
39  * All rights reserved.
40  *
41  * Redistribution and use in source and binary forms, with or without
42  * modification, are permitted provided that the following conditions
43  * are met:
44  * 1. Redistributions of source code must retain the above copyright
45  *    notice, this list of conditions and the following disclaimer.
46  * 2. Redistributions in binary form must reproduce the above copyright
47  *    notice, this list of conditions and the following disclaimer in the
48  *    documentation and/or other materials provided with the distribution.
49  * 3. The name of the author may not be used to endorse or promote products
50  *    derived from this software without specific prior written permission.
51  *
52  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
53  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
54  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
55  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
56  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
57  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
58  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
59  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
60  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
61  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
62  */
63 
64 #include <sys/cdefs.h>
65 #ifndef lint
66 __RCSID("$NetBSD: hack.mklev.c,v 1.9 2011/08/06 20:42:43 dholland Exp $");
67 #endif				/* not lint */
68 
69 #include <unistd.h>
70 #include <stdlib.h>
71 #include "hack.h"
72 #include "extern.h"
73 
74 #define somex() ((random()%(croom->hx-croom->lx+1))+croom->lx)
75 #define somey() ((random()%(croom->hy-croom->ly+1))+croom->ly)
76 
77 #include "def.mkroom.h"
78 #define	XLIM	4		/* define minimum required space around a
79 				 * room */
80 #define	YLIM	3
81 static boolean secret;		/* TRUE while making a vault: increase
82 				 * [XY]LIM */
83 static int smeq[MAXNROFROOMS + 1];
84 static const struct rm zerorm;
85 static schar nxcor;
86 static boolean goldseen;
87 
88 int             doorindex;
89 int             nroom;
90 
91 /* Definitions used by makerooms() and addrs() */
92 #define	MAXRS	50		/* max lth of temp rectangle table -
93 				 * arbitrary */
94 static struct rectangle {
95 	xchar           rlx, rly, rhx, rhy;
96 } rs[MAXRS + 1];
97 static int rscnt, rsmax;	/* 0..rscnt-1: currently under consideration */
98 /* rscnt..rsmax: discarded */
99 
100 static int makerooms(void);
101 static void addrs(int, int, int, int);
102 static void addrsx(int, int, int, int, boolean);
103 static int comp(const void *, const void *);
104 static coord finddpos(int, int, int, int);
105 static int okdoor(int, int);
106 static void dodoor(int, int, struct mkroom *);
107 static void dosdoor(int, int, struct mkroom *, int);
108 static int maker(schar, schar, schar, schar);
109 static void makecorridors(void);
110 static void join(int, int);
111 static void make_niches(void);
112 static void makevtele(void);
113 static void makeniche(boolean);
114 
115 void
makelevel(void)116 makelevel(void)
117 {
118 	struct mkroom  *croom, *troom;
119 	unsigned        tryct;
120 	int x, y;
121 
122 	nroom = 0;
123 	doorindex = 0;
124 	rooms[0].hx = -1;	/* in case we are in a maze */
125 
126 	for (x = 0; x < COLNO; x++)
127 		for (y = 0; y < ROWNO; y++)
128 			levl[x][y] = zerorm;
129 
130 	oinit();		/* assign level dependent obj probabilities */
131 
132 	if (dlevel >= rn1(3, 26)) {	/* there might be several mazes */
133 		makemaz();
134 		return;
135 	}
136 	/* construct the rooms */
137 	nroom = 0;
138 	secret = FALSE;
139 	(void) makerooms();
140 
141 	/* construct stairs (up and down in different rooms if possible) */
142 	croom = &rooms[rn2(nroom)];
143 	xdnstair = somex();
144 	ydnstair = somey();
145 	levl[xdnstair][ydnstair].scrsym = '>';
146 	levl[xdnstair][ydnstair].typ = STAIRS;
147 	if (nroom > 1) {
148 		troom = croom;
149 		croom = &rooms[rn2(nroom - 1)];
150 		if (croom >= troom)
151 			croom++;
152 	}
153 	xupstair = somex();	/* %% < and > might be in the same place */
154 	yupstair = somey();
155 	levl[xupstair][yupstair].scrsym = '<';
156 	levl[xupstair][yupstair].typ = STAIRS;
157 
158 	/* for each room: put things inside */
159 	for (croom = rooms; croom->hx > 0; croom++) {
160 
161 		/* put a sleeping monster inside */
162 		/*
163 		 * Note: monster may be on the stairs. This cannot be
164 		 * avoided: maybe the player fell through a trapdoor while a
165 		 * monster was on the stairs. Conclusion: we have to check
166 		 * for monsters on the stairs anyway.
167 		 */
168 		if (!rn2(3))
169 			(void)
170 				makemon((struct permonst *) 0, somex(), somey());
171 
172 		/* put traps and mimics inside */
173 		goldseen = FALSE;
174 		while (!rn2(8 - (dlevel / 6)))
175 			mktrap(0, 0, croom);
176 		if (!goldseen && !rn2(3))
177 			mkgold(0L, somex(), somey());
178 		if (!rn2(3)) {
179 			(void) mkobj_at(0, somex(), somey());
180 			tryct = 0;
181 			while (!rn2(5)) {
182 				if (++tryct > 100) {
183 					printf("tryct overflow4\n");
184 					break;
185 				}
186 				(void) mkobj_at(0, somex(), somey());
187 			}
188 		}
189 	}
190 
191 	qsort(rooms, nroom, sizeof(rooms[0]), comp);
192 	makecorridors();
193 	make_niches();
194 
195 	/* make a secret treasure vault, not connected to the rest */
196 	if (nroom <= (2 * MAXNROFROOMS / 3))
197 		if (rn2(3)) {
198 			troom = &rooms[nroom];
199 			secret = TRUE;
200 			if (makerooms()) {
201 				troom->rtype = VAULT;	/* treasure vault */
202 				for (x = troom->lx; x <= troom->hx; x++)
203 					for (y = troom->ly; y <= troom->hy; y++)
204 						mkgold((long) (rnd(dlevel * 100) + 50), x, y);
205 				if (!rn2(3))
206 					makevtele();
207 			}
208 		}
209 #ifndef QUEST
210 #ifdef WIZARD
211 	if (wizard && getenv("SHOPTYPE"))
212 		mkshop();
213 	else
214 #endif	/* WIZARD */
215 	if (dlevel > 1 && dlevel < 20 && rn2(dlevel) < 3)
216 		mkshop();
217 	else if (dlevel > 6 && !rn2(7))
218 		mkzoo(ZOO);
219 	else if (dlevel > 9 && !rn2(5))
220 		mkzoo(BEEHIVE);
221 	else if (dlevel > 11 && !rn2(6))
222 		mkzoo(MORGUE);
223 	else if (dlevel > 18 && !rn2(6))
224 		mkswamp();
225 #endif	/* QUEST */
226 }
227 
228 static int
makerooms(void)229 makerooms(void)
230 {
231 	struct rectangle *rsp;
232 	int             lx, ly, hx, hy, lowx, lowy, hix, hiy, dx, dy;
233 	int             tryct = 0, xlim, ylim;
234 
235 	/* init */
236 	xlim = XLIM + secret;
237 	ylim = YLIM + secret;
238 	if (nroom == 0) {
239 		rsp = rs;
240 		rsp->rlx = rsp->rly = 0;
241 		rsp->rhx = COLNO - 1;
242 		rsp->rhy = ROWNO - 1;
243 		rsmax = 1;
244 	}
245 	rscnt = rsmax;
246 
247 	/* make rooms until satisfied */
248 	while (rscnt > 0 && nroom < MAXNROFROOMS - 1) {
249 		if (!secret && nroom > (MAXNROFROOMS / 3) &&
250 		    !rn2((MAXNROFROOMS - nroom) * (MAXNROFROOMS - nroom)))
251 			return (0);
252 
253 		/* pick a rectangle */
254 		rsp = &rs[rn2(rscnt)];
255 		hx = rsp->rhx;
256 		hy = rsp->rhy;
257 		lx = rsp->rlx;
258 		ly = rsp->rly;
259 
260 		/* find size of room */
261 		if (secret)
262 			dx = dy = 1;
263 		else {
264 			dx = 2 + rn2((hx - lx - 8 > 20) ? 12 : 8);
265 			dy = 2 + rn2(4);
266 			if (dx * dy > 50)
267 				dy = 50 / dx;
268 		}
269 
270 		/* look whether our room will fit */
271 		if (hx - lx < dx + dx / 2 + 2 * xlim || hy - ly < dy + dy / 3 + 2 * ylim) {
272 			/* no, too small */
273 			/* maybe we throw this area out */
274 			if (secret || !rn2(MAXNROFROOMS + 1 - nroom - tryct)) {
275 				rscnt--;
276 				rs[rsmax] = *rsp;
277 				*rsp = rs[rscnt];
278 				rs[rscnt] = rs[rsmax];
279 				tryct = 0;
280 			} else
281 				tryct++;
282 			continue;
283 		}
284 		lowx = lx + xlim + rn2(hx - lx - dx - 2 * xlim + 1);
285 		lowy = ly + ylim + rn2(hy - ly - dy - 2 * ylim + 1);
286 		hix = lowx + dx;
287 		hiy = lowy + dy;
288 
289 		if (maker(lowx, dx, lowy, dy)) {
290 			if (secret)
291 				return (1);
292 			addrs(lowx - 1, lowy - 1, hix + 1, hiy + 1);
293 			tryct = 0;
294 		} else if (tryct++ > 100)
295 			break;
296 	}
297 	return (0);		/* failed to make vault - very strange */
298 }
299 
300 static void
addrs(int lowx,int lowy,int hix,int hiy)301 addrs(int lowx, int lowy, int hix, int hiy)
302 {
303 	struct rectangle *rsp;
304 	int             lx, ly, hx, hy, xlim, ylim;
305 	boolean         discarded;
306 
307 	xlim = XLIM + secret;
308 	ylim = YLIM + secret;
309 
310 	/* walk down since rscnt and rsmax change */
311 	for (rsp = &rs[rsmax - 1]; rsp >= rs; rsp--) {
312 
313 		if ((lx = rsp->rlx) > hix || (ly = rsp->rly) > hiy ||
314 		    (hx = rsp->rhx) < lowx || (hy = rsp->rhy) < lowy)
315 			continue;
316 		if ((discarded = (rsp >= &rs[rscnt]))) {
317 			*rsp = rs[--rsmax];
318 		} else {
319 			rsmax--;
320 			rscnt--;
321 			*rsp = rs[rscnt];
322 			if (rscnt != rsmax)
323 				rs[rscnt] = rs[rsmax];
324 		}
325 		if (lowy - ly > 2 * ylim + 4)
326 			addrsx(lx, ly, hx, lowy - 2, discarded);
327 		if (lowx - lx > 2 * xlim + 4)
328 			addrsx(lx, ly, lowx - 2, hy, discarded);
329 		if (hy - hiy > 2 * ylim + 4)
330 			addrsx(lx, hiy + 2, hx, hy, discarded);
331 		if (hx - hix > 2 * xlim + 4)
332 			addrsx(hix + 2, ly, hx, hy, discarded);
333 	}
334 }
335 
336 /* discarded: piece of a discarded area */
337 static void
addrsx(int lx,int ly,int hx,int hy,boolean discarded)338 addrsx(int lx, int ly, int hx, int hy, boolean discarded)
339 {
340 	struct rectangle *rsp;
341 
342 	/* check inclusions */
343 	for (rsp = rs; rsp < &rs[rsmax]; rsp++) {
344 		if (lx >= rsp->rlx && hx <= rsp->rhx &&
345 		    ly >= rsp->rly && hy <= rsp->rhy)
346 			return;
347 	}
348 
349 	/* make a new entry */
350 	if (rsmax >= MAXRS) {
351 #ifdef WIZARD
352 		if (wizard)
353 			pline("MAXRS may be too small.");
354 #endif	/* WIZARD */
355 		return;
356 	}
357 	rsmax++;
358 	if (!discarded) {
359 		*rsp = rs[rscnt];
360 		rsp = &rs[rscnt];
361 		rscnt++;
362 	}
363 	rsp->rlx = lx;
364 	rsp->rly = ly;
365 	rsp->rhx = hx;
366 	rsp->rhy = hy;
367 }
368 
369 static int
comp(const void * vx,const void * vy)370 comp(const void *vx, const void *vy)
371 {
372 	const struct mkroom  *x = vx, *y = vy;
373 	if (x->lx < y->lx)
374 		return (-1);
375 	return (x->lx > y->lx);
376 }
377 
378 static coord
finddpos(int xl,int yl,int xh,int yh)379 finddpos(int xl, int yl, int xh, int yh)
380 {
381 	coord           ff;
382 	int x, y;
383 
384 	x = (xl == xh) ? xl : (xl + rn2(xh - xl + 1));
385 	y = (yl == yh) ? yl : (yl + rn2(yh - yl + 1));
386 	if (okdoor(x, y))
387 		goto gotit;
388 
389 	for (x = xl; x <= xh; x++)
390 		for (y = yl; y <= yh; y++)
391 			if (okdoor(x, y))
392 				goto gotit;
393 
394 	for (x = xl; x <= xh; x++)
395 		for (y = yl; y <= yh; y++)
396 			if (levl[x][y].typ == DOOR || levl[x][y].typ == SDOOR)
397 				goto gotit;
398 	/* cannot find something reasonable -- strange */
399 	x = xl;
400 	y = yh;
401 gotit:
402 	ff.x = x;
403 	ff.y = y;
404 	return (ff);
405 }
406 
407 /* see whether it is allowable to create a door at [x,y] */
408 static int
okdoor(int x,int y)409 okdoor(int x, int y)
410 {
411 	if (levl[x - 1][y].typ == DOOR || levl[x + 1][y].typ == DOOR ||
412 	    levl[x][y + 1].typ == DOOR || levl[x][y - 1].typ == DOOR ||
413 	    levl[x - 1][y].typ == SDOOR || levl[x + 1][y].typ == SDOOR ||
414 	    levl[x][y - 1].typ == SDOOR || levl[x][y + 1].typ == SDOOR ||
415 	    (levl[x][y].typ != HWALL && levl[x][y].typ != VWALL) ||
416 	    doorindex >= DOORMAX)
417 		return (0);
418 	return (1);
419 }
420 
421 static void
dodoor(int x,int y,struct mkroom * aroom)422 dodoor(int x, int y, struct mkroom *aroom)
423 {
424 	if (doorindex >= DOORMAX) {
425 		impossible("DOORMAX exceeded?");
426 		return;
427 	}
428 	if (!okdoor(x, y) && nxcor)
429 		return;
430 	dosdoor(x, y, aroom, rn2(8) ? DOOR : SDOOR);
431 }
432 
433 static void
dosdoor(int x,int y,struct mkroom * aroom,int type)434 dosdoor(int x, int y, struct mkroom *aroom, int type)
435 {
436 	struct mkroom  *broom;
437 	int tmp;
438 
439 	if (!IS_WALL(levl[x][y].typ))	/* avoid SDOORs with '+' as scrsym */
440 		type = DOOR;
441 	levl[x][y].typ = type;
442 	if (type == DOOR)
443 		levl[x][y].scrsym = '+';
444 	aroom->doorct++;
445 	broom = aroom + 1;
446 	if (broom->hx < 0)
447 		tmp = doorindex;
448 	else
449 		for (tmp = doorindex; tmp > broom->fdoor; tmp--)
450 			doors[tmp] = doors[tmp - 1];
451 	doorindex++;
452 	doors[tmp].x = x;
453 	doors[tmp].y = y;
454 	for (; broom->hx >= 0; broom++)
455 		broom->fdoor++;
456 }
457 
458 /* Only called from makerooms() */
459 static int
maker(schar lowx,schar ddx,schar lowy,schar ddy)460 maker(schar lowx, schar ddx, schar lowy, schar ddy)
461 {
462 	struct mkroom  *croom;
463 	int x, y, hix = lowx + ddx, hiy = lowy + ddy;
464 	int xlim = XLIM + secret, ylim = YLIM + secret;
465 
466 	if (nroom >= MAXNROFROOMS)
467 		return (0);
468 	if (lowx < XLIM)
469 		lowx = XLIM;
470 	if (lowy < YLIM)
471 		lowy = YLIM;
472 	if (hix > COLNO - XLIM - 1)
473 		hix = COLNO - XLIM - 1;
474 	if (hiy > ROWNO - YLIM - 1)
475 		hiy = ROWNO - YLIM - 1;
476 chk:
477 	if (hix <= lowx || hiy <= lowy)
478 		return (0);
479 
480 	/* check area around room (and make room smaller if necessary) */
481 	for (x = lowx - xlim; x <= hix + xlim; x++) {
482 		for (y = lowy - ylim; y <= hiy + ylim; y++) {
483 			if (levl[x][y].typ) {
484 #ifdef WIZARD
485 				if (wizard && !secret)
486 					pline("Strange area [%d,%d] in maker().", x, y);
487 #endif	/* WIZARD */
488 				if (!rn2(3))
489 					return (0);
490 				if (x < lowx)
491 					lowx = x + xlim + 1;
492 				else
493 					hix = x - xlim - 1;
494 				if (y < lowy)
495 					lowy = y + ylim + 1;
496 				else
497 					hiy = y - ylim - 1;
498 				goto chk;
499 			}
500 		}
501 	}
502 
503 	croom = &rooms[nroom];
504 
505 	/* on low levels the room is lit (usually) */
506 	/* secret vaults are always lit */
507 	if ((rnd(dlevel) < 10 && rn2(77)) || (ddx == 1 && ddy == 1)) {
508 		for (x = lowx - 1; x <= hix + 1; x++)
509 			for (y = lowy - 1; y <= hiy + 1; y++)
510 				levl[x][y].lit = 1;
511 		croom->rlit = 1;
512 	} else
513 		croom->rlit = 0;
514 	croom->lx = lowx;
515 	croom->hx = hix;
516 	croom->ly = lowy;
517 	croom->hy = hiy;
518 	croom->rtype = croom->doorct = croom->fdoor = 0;
519 
520 	for (x = lowx - 1; x <= hix + 1; x++)
521 		for (y = lowy - 1; y <= hiy + 1; y += (hiy - lowy + 2)) {
522 			levl[x][y].scrsym = '-';
523 			levl[x][y].typ = HWALL;
524 		}
525 	for (x = lowx - 1; x <= hix + 1; x += (hix - lowx + 2))
526 		for (y = lowy; y <= hiy; y++) {
527 			levl[x][y].scrsym = '|';
528 			levl[x][y].typ = VWALL;
529 		}
530 	for (x = lowx; x <= hix; x++)
531 		for (y = lowy; y <= hiy; y++) {
532 			levl[x][y].scrsym = '.';
533 			levl[x][y].typ = ROOM;
534 		}
535 
536 	smeq[nroom] = nroom;
537 	croom++;
538 	croom->hx = -1;
539 	nroom++;
540 	return (1);
541 }
542 
543 static void
makecorridors(void)544 makecorridors(void)
545 {
546 	int a, b;
547 
548 	nxcor = 0;
549 	for (a = 0; a < nroom - 1; a++)
550 		join(a, a + 1);
551 	for (a = 0; a < nroom - 2; a++)
552 		if (smeq[a] != smeq[a + 2])
553 			join(a, a + 2);
554 	for (a = 0; a < nroom; a++)
555 		for (b = 0; b < nroom; b++)
556 			if (smeq[a] != smeq[b])
557 				join(a, b);
558 	if (nroom > 2)
559 		for (nxcor = rn2(nroom) + 4; nxcor; nxcor--) {
560 			a = rn2(nroom);
561 			b = rn2(nroom - 2);
562 			if (b >= a)
563 				b += 2;
564 			join(a, b);
565 		}
566 }
567 
568 static void
join(int a,int b)569 join(int a, int b)
570 {
571 	coord           cc, tt;
572 	int tx, ty, xx, yy;
573 	struct rm      *crm;
574 	struct mkroom  *croom, *troom;
575 	int dx, dy, dix, diy, cct;
576 
577 	croom = &rooms[a];
578 	troom = &rooms[b];
579 
580 	/*
581 	 * find positions cc and tt for doors in croom and troom and
582 	 * direction for a corridor between them
583 	 */
584 
585 	if (troom->hx < 0 || croom->hx < 0 || doorindex >= DOORMAX)
586 		return;
587 	if (troom->lx > croom->hx) {
588 		dx = 1;
589 		dy = 0;
590 		xx = croom->hx + 1;
591 		tx = troom->lx - 1;
592 		cc = finddpos(xx, croom->ly, xx, croom->hy);
593 		tt = finddpos(tx, troom->ly, tx, troom->hy);
594 	} else if (troom->hy < croom->ly) {
595 		dy = -1;
596 		dx = 0;
597 		yy = croom->ly - 1;
598 		cc = finddpos(croom->lx, yy, croom->hx, yy);
599 		ty = troom->hy + 1;
600 		tt = finddpos(troom->lx, ty, troom->hx, ty);
601 	} else if (troom->hx < croom->lx) {
602 		dx = -1;
603 		dy = 0;
604 		xx = croom->lx - 1;
605 		tx = troom->hx + 1;
606 		cc = finddpos(xx, croom->ly, xx, croom->hy);
607 		tt = finddpos(tx, troom->ly, tx, troom->hy);
608 	} else {
609 		dy = 1;
610 		dx = 0;
611 		yy = croom->hy + 1;
612 		ty = troom->ly - 1;
613 		cc = finddpos(croom->lx, yy, croom->hx, yy);
614 		tt = finddpos(troom->lx, ty, troom->hx, ty);
615 	}
616 	xx = cc.x;
617 	yy = cc.y;
618 	tx = tt.x - dx;
619 	ty = tt.y - dy;
620 	if (nxcor && levl[xx + dx][yy + dy].typ)
621 		return;
622 	dodoor(xx, yy, croom);
623 
624 	cct = 0;
625 	while (xx != tx || yy != ty) {
626 		xx += dx;
627 		yy += dy;
628 
629 		/* loop: dig corridor at [xx,yy] and find new [xx,yy] */
630 		if (cct++ > 500 || (nxcor && !rn2(35)))
631 			return;
632 
633 		if (xx == COLNO - 1 || xx == 0 || yy == 0 || yy == ROWNO - 1)
634 			return;	/* impossible */
635 
636 		crm = &levl[xx][yy];
637 		if (!(crm->typ)) {
638 			if (rn2(100)) {
639 				crm->typ = CORR;
640 				crm->scrsym = CORR_SYM;
641 				if (nxcor && !rn2(50))
642 					(void) mkobj_at(ROCK_SYM, xx, yy);
643 			} else {
644 				crm->typ = SCORR;
645 				crm->scrsym = ' ';
646 			}
647 		} else if (crm->typ != CORR && crm->typ != SCORR) {
648 			/* strange ... */
649 			return;
650 		}
651 		/* find next corridor position */
652 		dix = abs(xx - tx);
653 		diy = abs(yy - ty);
654 
655 		/* do we have to change direction ? */
656 		if (dy && dix > diy) {
657 			int ddx = (xx > tx) ? -1 : 1;
658 
659 			crm = &levl[xx + ddx][yy];
660 			if (!crm->typ || crm->typ == CORR || crm->typ == SCORR) {
661 				dx = ddx;
662 				dy = 0;
663 				continue;
664 			}
665 		} else if (dx && diy > dix) {
666 			int ddy = (yy > ty) ? -1 : 1;
667 
668 			crm = &levl[xx][yy + ddy];
669 			if (!crm->typ || crm->typ == CORR || crm->typ == SCORR) {
670 				dy = ddy;
671 				dx = 0;
672 				continue;
673 			}
674 		}
675 		/* continue straight on? */
676 		crm = &levl[xx + dx][yy + dy];
677 		if (!crm->typ || crm->typ == CORR || crm->typ == SCORR)
678 			continue;
679 
680 		/* no, what must we do now?? */
681 		if (dx) {
682 			dx = 0;
683 			dy = (ty < yy) ? -1 : 1;
684 			crm = &levl[xx + dx][yy + dy];
685 			if (!crm->typ || crm->typ == CORR || crm->typ == SCORR)
686 				continue;
687 			dy = -dy;
688 			continue;
689 		} else {
690 			dy = 0;
691 			dx = (tx < xx) ? -1 : 1;
692 			crm = &levl[xx + dx][yy + dy];
693 			if (!crm->typ || crm->typ == CORR || crm->typ == SCORR)
694 				continue;
695 			dx = -dx;
696 			continue;
697 		}
698 	}
699 
700 	/* we succeeded in digging the corridor */
701 	dodoor(tt.x, tt.y, troom);
702 
703 	if (smeq[a] < smeq[b])
704 		smeq[b] = smeq[a];
705 	else
706 		smeq[a] = smeq[b];
707 }
708 
709 static void
make_niches(void)710 make_niches(void)
711 {
712 	int             ct = rnd(nroom / 2 + 1);
713 	while (ct--)
714 		makeniche(FALSE);
715 }
716 
717 static void
makevtele(void)718 makevtele(void)
719 {
720 	makeniche(TRUE);
721 }
722 
723 static void
makeniche(boolean with_trap)724 makeniche(boolean with_trap)
725 {
726 	struct mkroom  *aroom;
727 	struct rm      *rm;
728 	int             vct = 8;
729 	coord           dd;
730 	int		dy, xx, yy;
731 	struct trap    *ttmp;
732 
733 	if (doorindex < DOORMAX)
734 		while (vct--) {
735 			aroom = &rooms[rn2(nroom - 1)];
736 			if (aroom->rtype != 0)
737 				continue;	/* not an ordinary room */
738 			if (aroom->doorct == 1 && rn2(5))
739 				continue;
740 			if (rn2(2)) {
741 				dy = 1;
742 				dd = finddpos(aroom->lx, aroom->hy + 1, aroom->hx, aroom->hy + 1);
743 			} else {
744 				dy = -1;
745 				dd = finddpos(aroom->lx, aroom->ly - 1, aroom->hx, aroom->ly - 1);
746 			}
747 			xx = dd.x;
748 			yy = dd.y;
749 			if ((rm = &levl[xx][yy + dy])->typ)
750 				continue;
751 			if (with_trap || !rn2(4)) {
752 				rm->typ = SCORR;
753 				rm->scrsym = ' ';
754 				if (with_trap) {
755 					ttmp = maketrap(xx, yy + dy, TELEP_TRAP);
756 					ttmp->once = 1;
757 					make_engr_at(xx, yy - dy, "ad ae?ar um");
758 				}
759 				dosdoor(xx, yy, aroom, SDOOR);
760 			} else {
761 				rm->typ = CORR;
762 				rm->scrsym = CORR_SYM;
763 				if (rn2(7))
764 					dosdoor(xx, yy, aroom, rn2(5) ? SDOOR : DOOR);
765 				else {
766 					mksobj_at(SCR_TELEPORTATION, xx, yy + dy);
767 					if (!rn2(3))
768 						(void) mkobj_at(0, xx, yy + dy);
769 				}
770 			}
771 			return;
772 		}
773 }
774 
775 /* make a trap somewhere (in croom if mazeflag = 0) */
776 void
mktrap(int num,int mazeflag,struct mkroom * croom)777 mktrap(int num, int mazeflag, struct mkroom *croom)
778 {
779 	struct trap    *ttmp;
780 	int             kind, nopierc, nomimic, fakedoor, fakegold, tryct = 0;
781 	xchar           mx, my;
782 
783 	if (!num || num >= TRAPNUM) {
784 		nopierc = (dlevel < 4) ? 1 : 0;
785 		nomimic = (dlevel < 9 || goldseen) ? 1 : 0;
786 		if (strchr(fut_geno, 'M'))
787 			nomimic = 1;
788 		kind = rn2(TRAPNUM - nopierc - nomimic);
789 		/* note: PIERC = 7, MIMIC = 8, TRAPNUM = 9 */
790 	} else
791 		kind = num;
792 
793 	if (kind == MIMIC) {
794 		struct monst   *mtmp;
795 
796 		fakedoor = (!rn2(3) && !mazeflag);
797 		fakegold = (!fakedoor && !rn2(2));
798 		if (fakegold)
799 			goldseen = TRUE;
800 		do {
801 			if (++tryct > 200)
802 				return;
803 			if (fakedoor) {
804 				/* note: fakedoor maybe on actual door */
805 				if (rn2(2)) {
806 					if (rn2(2))
807 						mx = croom->hx + 1;
808 					else
809 						mx = croom->lx - 1;
810 					my = somey();
811 				} else {
812 					if (rn2(2))
813 						my = croom->hy + 1;
814 					else
815 						my = croom->ly - 1;
816 					mx = somex();
817 				}
818 			} else if (mazeflag) {
819 				coord           mm;
820 				mm = mazexy();
821 				mx = mm.x;
822 				my = mm.y;
823 			} else {
824 				mx = somex();
825 				my = somey();
826 			}
827 		} while (m_at(mx, my) || levl[mx][my].typ == STAIRS);
828 		if ((mtmp = makemon(PM_MIMIC, mx, my)) != NULL) {
829 			mtmp->mimic = 1;
830 			mtmp->mappearance =
831 				fakegold ? '$' : fakedoor ? '+' :
832 				(mazeflag && rn2(2)) ? AMULET_SYM :
833 				"=/)%?![<>"[rn2(9)];
834 		}
835 		return;
836 	}
837 	do {
838 		if (++tryct > 200)
839 			return;
840 		if (mazeflag) {
841 			coord           mm;
842 			mm = mazexy();
843 			mx = mm.x;
844 			my = mm.y;
845 		} else {
846 			mx = somex();
847 			my = somey();
848 		}
849 	} while (t_at(mx, my) || levl[mx][my].typ == STAIRS);
850 	ttmp = maketrap(mx, my, kind);
851 	if (mazeflag && !rn2(10) && ttmp->ttyp < PIERC)
852 		ttmp->tseen = 1;
853 }
854