NetBSD/games/hack/hack.mklev.c

/*	$NetBSD: hack.mklev.c,v 1.9 2011/08/06 20:42:43 dholland Exp $	*/

/*
 * Copyright (c) 1985, Stichting Centrum voor Wiskunde en Informatica,
 * Amsterdam
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of the Stichting Centrum voor Wiskunde en
 * Informatica, nor the names of its contributors may be used to endorse or
 * promote products derived from this software without specific prior
 * written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Copyright (c) 1982 Jay Fenlason <hack@gnu.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: hack.mklev.c,v 1.9 2011/08/06 20:42:43 dholland Exp $");
#endif				/* not lint */

#include <unistd.h>
#include <stdlib.h>
#include "hack.h"
#include "extern.h"

#define somex() ((random()%(croom->hx-croom->lx+1))+croom->lx)
#define somey() ((random()%(croom->hy-croom->ly+1))+croom->ly)

#include "def.mkroom.h"
#define	XLIM	4		/* define minimum required space around a
				 * room */
#define	YLIM	3
static boolean secret;		/* TRUE while making a vault: increase
				 * [XY]LIM */
static int smeq[MAXNROFROOMS + 1];
static const struct rm zerorm;
static schar nxcor;
static boolean goldseen;

int             doorindex;
int             nroom;

/* Definitions used by makerooms() and addrs() */
#define	MAXRS	50		/* max lth of temp rectangle table -
				 * arbitrary */
static struct rectangle {
	xchar           rlx, rly, rhx, rhy;
} rs[MAXRS + 1];
static int rscnt, rsmax;	/* 0..rscnt-1: currently under consideration */
/* rscnt..rsmax: discarded */

static int makerooms(void);
static void addrs(int, int, int, int);
static void addrsx(int, int, int, int, boolean);
static int comp(const void *, const void *);
static coord finddpos(int, int, int, int);
static int okdoor(int, int);
static void dodoor(int, int, struct mkroom *);
static void dosdoor(int, int, struct mkroom *, int);
static int maker(schar, schar, schar, schar);
static void makecorridors(void);
static void join(int, int);
static void make_niches(void);
static void makevtele(void);
static void makeniche(boolean);

void
makelevel(void)
{
	struct mkroom  *croom, *troom;
	unsigned        tryct;
	int x, y;

	nroom = 0;
	doorindex = 0;
	rooms[0].hx = -1;	/* in case we are in a maze */

	for (x = 0; x < COLNO; x++)
		for (y = 0; y < ROWNO; y++)
			levl[x][y] = zerorm;

	oinit();		/* assign level dependent obj probabilities */

	if (dlevel >= rn1(3, 26)) {	/* there might be several mazes */
		makemaz();
		return;
	}
	/* construct the rooms */
	nroom = 0;
	secret = FALSE;
	(void) makerooms();

	/* construct stairs (up and down in different rooms if possible) */
	croom = &rooms[rn2(nroom)];
	xdnstair = somex();
	ydnstair = somey();
	levl[xdnstair][ydnstair].scrsym = '>';
	levl[xdnstair][ydnstair].typ = STAIRS;
	if (nroom > 1) {
		troom = croom;
		croom = &rooms[rn2(nroom - 1)];
		if (croom >= troom)
			croom++;
	}
	xupstair = somex();	/* %% < and > might be in the same place */
	yupstair = somey();
	levl[xupstair][yupstair].scrsym = '<';
	levl[xupstair][yupstair].typ = STAIRS;

	/* for each room: put things inside */
	for (croom = rooms; croom->hx > 0; croom++) {

		/* put a sleeping monster inside */
		/*
		 * Note: monster may be on the stairs. This cannot be
		 * avoided: maybe the player fell through a trapdoor while a
		 * monster was on the stairs. Conclusion: we have to check
		 * for monsters on the stairs anyway.
		 */
		if (!rn2(3))
			(void)
				makemon((struct permonst *) 0, somex(), somey());

		/* put traps and mimics inside */
		goldseen = FALSE;
		while (!rn2(8 - (dlevel / 6)))
			mktrap(0, 0, croom);
		if (!goldseen && !rn2(3))
			mkgold(0L, somex(), somey());
		if (!rn2(3)) {
			(void) mkobj_at(0, somex(), somey());
			tryct = 0;
			while (!rn2(5)) {
				if (++tryct > 100) {
					printf("tryct overflow4\n");
					break;
				}
				(void) mkobj_at(0, somex(), somey());
			}
		}
	}

	qsort(rooms, nroom, sizeof(rooms[0]), comp);
	makecorridors();
	make_niches();

	/* make a secret treasure vault, not connected to the rest */
	if (nroom <= (2 * MAXNROFROOMS / 3))
		if (rn2(3)) {
			troom = &rooms[nroom];
			secret = TRUE;
			if (makerooms()) {
				troom->rtype = VAULT;	/* treasure vault */
				for (x = troom->lx; x <= troom->hx; x++)
					for (y = troom->ly; y <= troom->hy; y++)
						mkgold((long) (rnd(dlevel * 100) + 50), x, y);
				if (!rn2(3))
					makevtele();
			}
		}
#ifndef QUEST
#ifdef WIZARD
	if (wizard && getenv("SHOPTYPE"))
		mkshop();
	else
#endif	/* WIZARD */
	if (dlevel > 1 && dlevel < 20 && rn2(dlevel) < 3)
		mkshop();
	else if (dlevel > 6 && !rn2(7))
		mkzoo(ZOO);
	else if (dlevel > 9 && !rn2(5))
		mkzoo(BEEHIVE);
	else if (dlevel > 11 && !rn2(6))
		mkzoo(MORGUE);
	else if (dlevel > 18 && !rn2(6))
		mkswamp();
#endif	/* QUEST */
}

static int
makerooms(void)
{
	struct rectangle *rsp;
	int             lx, ly, hx, hy, lowx, lowy, hix, hiy, dx, dy;
	int             tryct = 0, xlim, ylim;

	/* init */
	xlim = XLIM + secret;
	ylim = YLIM + secret;
	if (nroom == 0) {
		rsp = rs;
		rsp->rlx = rsp->rly = 0;
		rsp->rhx = COLNO - 1;
		rsp->rhy = ROWNO - 1;
		rsmax = 1;
	}
	rscnt = rsmax;

	/* make rooms until satisfied */
	while (rscnt > 0 && nroom < MAXNROFROOMS - 1) {
		if (!secret && nroom > (MAXNROFROOMS / 3) &&
		    !rn2((MAXNROFROOMS - nroom) * (MAXNROFROOMS - nroom)))
			return (0);

		/* pick a rectangle */
		rsp = &rs[rn2(rscnt)];
		hx = rsp->rhx;
		hy = rsp->rhy;
		lx = rsp->rlx;
		ly = rsp->rly;

		/* find size of room */
		if (secret)
			dx = dy = 1;
		else {
			dx = 2 + rn2((hx - lx - 8 > 20) ? 12 : 8);
			dy = 2 + rn2(4);
			if (dx * dy > 50)
				dy = 50 / dx;
		}

		/* look whether our room will fit */
		if (hx - lx < dx + dx / 2 + 2 * xlim || hy - ly < dy + dy / 3 + 2 * ylim) {
			/* no, too small */
			/* maybe we throw this area out */
			if (secret || !rn2(MAXNROFROOMS + 1 - nroom - tryct)) {
				rscnt--;
				rs[rsmax] = *rsp;
				*rsp = rs[rscnt];
				rs[rscnt] = rs[rsmax];
				tryct = 0;
			} else
				tryct++;
			continue;
		}
		lowx = lx + xlim + rn2(hx - lx - dx - 2 * xlim + 1);
		lowy = ly + ylim + rn2(hy - ly - dy - 2 * ylim + 1);
		hix = lowx + dx;
		hiy = lowy + dy;

		if (maker(lowx, dx, lowy, dy)) {
			if (secret)
				return (1);
			addrs(lowx - 1, lowy - 1, hix + 1, hiy + 1);
			tryct = 0;
		} else if (tryct++ > 100)
			break;
	}
	return (0);		/* failed to make vault - very strange */
}

static void
addrs(int lowx, int lowy, int hix, int hiy)
{
	struct rectangle *rsp;
	int             lx, ly, hx, hy, xlim, ylim;
	boolean         discarded;

	xlim = XLIM + secret;
	ylim = YLIM + secret;

	/* walk down since rscnt and rsmax change */
	for (rsp = &rs[rsmax - 1]; rsp >= rs; rsp--) {

		if ((lx = rsp->rlx) > hix || (ly = rsp->rly) > hiy ||
		    (hx = rsp->rhx) < lowx || (hy = rsp->rhy) < lowy)
			continue;
		if ((discarded = (rsp >= &rs[rscnt]))) {
			*rsp = rs[--rsmax];
		} else {
			rsmax--;
			rscnt--;
			*rsp = rs[rscnt];
			if (rscnt != rsmax)
				rs[rscnt] = rs[rsmax];
		}
		if (lowy - ly > 2 * ylim + 4)
			addrsx(lx, ly, hx, lowy - 2, discarded);
		if (lowx - lx > 2 * xlim + 4)
			addrsx(lx, ly, lowx - 2, hy, discarded);
		if (hy - hiy > 2 * ylim + 4)
			addrsx(lx, hiy + 2, hx, hy, discarded);
		if (hx - hix > 2 * xlim + 4)
			addrsx(hix + 2, ly, hx, hy, discarded);
	}
}

/* discarded: piece of a discarded area */
static void
addrsx(int lx, int ly, int hx, int hy, boolean discarded)
{
	struct rectangle *rsp;

	/* check inclusions */
	for (rsp = rs; rsp < &rs[rsmax]; rsp++) {
		if (lx >= rsp->rlx && hx <= rsp->rhx &&
		    ly >= rsp->rly && hy <= rsp->rhy)
			return;
	}

	/* make a new entry */
	if (rsmax >= MAXRS) {
#ifdef WIZARD
		if (wizard)
			pline("MAXRS may be too small.");
#endif	/* WIZARD */
		return;
	}
	rsmax++;
	if (!discarded) {
		*rsp = rs[rscnt];
		rsp = &rs[rscnt];
		rscnt++;
	}
	rsp->rlx = lx;
	rsp->rly = ly;
	rsp->rhx = hx;
	rsp->rhy = hy;
}

static int
comp(const void *vx, const void *vy)
{
	const struct mkroom  *x = vx, *y = vy;
	if (x->lx < y->lx)
		return (-1);
	return (x->lx > y->lx);
}

static coord
finddpos(int xl, int yl, int xh, int yh)
{
	coord           ff;
	int x, y;

	x = (xl == xh) ? xl : (xl + rn2(xh - xl + 1));
	y = (yl == yh) ? yl : (yl + rn2(yh - yl + 1));
	if (okdoor(x, y))
		goto gotit;

	for (x = xl; x <= xh; x++)
		for (y = yl; y <= yh; y++)
			if (okdoor(x, y))
				goto gotit;

	for (x = xl; x <= xh; x++)
		for (y = yl; y <= yh; y++)
			if (levl[x][y].typ == DOOR || levl[x][y].typ == SDOOR)
				goto gotit;
	/* cannot find something reasonable -- strange */
	x = xl;
	y = yh;
gotit:
	ff.x = x;
	ff.y = y;
	return (ff);
}

/* see whether it is allowable to create a door at [x,y] */
static int
okdoor(int x, int y)
{
	if (levl[x - 1][y].typ == DOOR || levl[x + 1][y].typ == DOOR ||
	    levl[x][y + 1].typ == DOOR || levl[x][y - 1].typ == DOOR ||
	    levl[x - 1][y].typ == SDOOR || levl[x + 1][y].typ == SDOOR ||
	    levl[x][y - 1].typ == SDOOR || levl[x][y + 1].typ == SDOOR ||
	    (levl[x][y].typ != HWALL && levl[x][y].typ != VWALL) ||
	    doorindex >= DOORMAX)
		return (0);
	return (1);
}

static void
dodoor(int x, int y, struct mkroom *aroom)
{
	if (doorindex >= DOORMAX) {
		impossible("DOORMAX exceeded?");
		return;
	}
	if (!okdoor(x, y) && nxcor)
		return;
	dosdoor(x, y, aroom, rn2(8) ? DOOR : SDOOR);
}

static void
dosdoor(int x, int y, struct mkroom *aroom, int type)
{
	struct mkroom  *broom;
	int tmp;

	if (!IS_WALL(levl[x][y].typ))	/* avoid SDOORs with '+' as scrsym */
		type = DOOR;
	levl[x][y].typ = type;
	if (type == DOOR)
		levl[x][y].scrsym = '+';
	aroom->doorct++;
	broom = aroom + 1;
	if (broom->hx < 0)
		tmp = doorindex;
	else
		for (tmp = doorindex; tmp > broom->fdoor; tmp--)
			doors[tmp] = doors[tmp - 1];
	doorindex++;
	doors[tmp].x = x;
	doors[tmp].y = y;
	for (; broom->hx >= 0; broom++)
		broom->fdoor++;
}

/* Only called from makerooms() */
static int
maker(schar lowx, schar ddx, schar lowy, schar ddy)
{
	struct mkroom  *croom;
	int x, y, hix = lowx + ddx, hiy = lowy + ddy;
	int xlim = XLIM + secret, ylim = YLIM + secret;

	if (nroom >= MAXNROFROOMS)
		return (0);
	if (lowx < XLIM)
		lowx = XLIM;
	if (lowy < YLIM)
		lowy = YLIM;
	if (hix > COLNO - XLIM - 1)
		hix = COLNO - XLIM - 1;
	if (hiy > ROWNO - YLIM - 1)
		hiy = ROWNO - YLIM - 1;
chk:
	if (hix <= lowx || hiy <= lowy)
		return (0);

	/* check area around room (and make room smaller if necessary) */
	for (x = lowx - xlim; x <= hix + xlim; x++) {
		for (y = lowy - ylim; y <= hiy + ylim; y++) {
			if (levl[x][y].typ) {
#ifdef WIZARD
				if (wizard && !secret)
					pline("Strange area [%d,%d] in maker().", x, y);
#endif	/* WIZARD */
				if (!rn2(3))
					return (0);
				if (x < lowx)
					lowx = x + xlim + 1;
				else
					hix = x - xlim - 1;
				if (y < lowy)
					lowy = y + ylim + 1;
				else
					hiy = y - ylim - 1;
				goto chk;
			}
		}
	}

	croom = &rooms[nroom];

	/* on low levels the room is lit (usually) */
	/* secret vaults are always lit */
	if ((rnd(dlevel) < 10 && rn2(77)) || (ddx == 1 && ddy == 1)) {
		for (x = lowx - 1; x <= hix + 1; x++)
			for (y = lowy - 1; y <= hiy + 1; y++)
				levl[x][y].lit = 1;
		croom->rlit = 1;
	} else
		croom->rlit = 0;
	croom->lx = lowx;
	croom->hx = hix;
	croom->ly = lowy;
	croom->hy = hiy;
	croom->rtype = croom->doorct = croom->fdoor = 0;

	for (x = lowx - 1; x <= hix + 1; x++)
		for (y = lowy - 1; y <= hiy + 1; y += (hiy - lowy + 2)) {
			levl[x][y].scrsym = '-';
			levl[x][y].typ = HWALL;
		}
	for (x = lowx - 1; x <= hix + 1; x += (hix - lowx + 2))
		for (y = lowy; y <= hiy; y++) {
			levl[x][y].scrsym = '|';
			levl[x][y].typ = VWALL;
		}
	for (x = lowx; x <= hix; x++)
		for (y = lowy; y <= hiy; y++) {
			levl[x][y].scrsym = '.';
			levl[x][y].typ = ROOM;
		}

	smeq[nroom] = nroom;
	croom++;
	croom->hx = -1;
	nroom++;
	return (1);
}

static void
makecorridors(void)
{
	int a, b;

	nxcor = 0;
	for (a = 0; a < nroom - 1; a++)
		join(a, a + 1);
	for (a = 0; a < nroom - 2; a++)
		if (smeq[a] != smeq[a + 2])
			join(a, a + 2);
	for (a = 0; a < nroom; a++)
		for (b = 0; b < nroom; b++)
			if (smeq[a] != smeq[b])
				join(a, b);
	if (nroom > 2)
		for (nxcor = rn2(nroom) + 4; nxcor; nxcor--) {
			a = rn2(nroom);
			b = rn2(nroom - 2);
			if (b >= a)
				b += 2;
			join(a, b);
		}
}

static void
join(int a, int b)
{
	coord           cc, tt;
	int tx, ty, xx, yy;
	struct rm      *crm;
	struct mkroom  *croom, *troom;
	int dx, dy, dix, diy, cct;

	croom = &rooms[a];
	troom = &rooms[b];

	/*
	 * find positions cc and tt for doors in croom and troom and
	 * direction for a corridor between them
	 */

	if (troom->hx < 0 || croom->hx < 0 || doorindex >= DOORMAX)
		return;
	if (troom->lx > croom->hx) {
		dx = 1;
		dy = 0;
		xx = croom->hx + 1;
		tx = troom->lx - 1;
		cc = finddpos(xx, croom->ly, xx, croom->hy);
		tt = finddpos(tx, troom->ly, tx, troom->hy);
	} else if (troom->hy < croom->ly) {
		dy = -1;
		dx = 0;
		yy = croom->ly - 1;
		cc = finddpos(croom->lx, yy, croom->hx, yy);
		ty = troom->hy + 1;
		tt = finddpos(troom->lx, ty, troom->hx, ty);
	} else if (troom->hx < croom->lx) {
		dx = -1;
		dy = 0;
		xx = croom->lx - 1;
		tx = troom->hx + 1;
		cc = finddpos(xx, croom->ly, xx, croom->hy);
		tt = finddpos(tx, troom->ly, tx, troom->hy);
	} else {
		dy = 1;
		dx = 0;
		yy = croom->hy + 1;
		ty = troom->ly - 1;
		cc = finddpos(croom->lx, yy, croom->hx, yy);
		tt = finddpos(troom->lx, ty, troom->hx, ty);
	}
	xx = cc.x;
	yy = cc.y;
	tx = tt.x - dx;
	ty = tt.y - dy;
	if (nxcor && levl[xx + dx][yy + dy].typ)
		return;
	dodoor(xx, yy, croom);

	cct = 0;
	while (xx != tx || yy != ty) {
		xx += dx;
		yy += dy;

		/* loop: dig corridor at [xx,yy] and find new [xx,yy] */
		if (cct++ > 500 || (nxcor && !rn2(35)))
			return;

		if (xx == COLNO - 1 || xx == 0 || yy == 0 || yy == ROWNO - 1)
			return;	/* impossible */

		crm = &levl[xx][yy];
		if (!(crm->typ)) {
			if (rn2(100)) {
				crm->typ = CORR;
				crm->scrsym = CORR_SYM;
				if (nxcor && !rn2(50))
					(void) mkobj_at(ROCK_SYM, xx, yy);
			} else {
				crm->typ = SCORR;
				crm->scrsym = ' ';
			}
		} else if (crm->typ != CORR && crm->typ != SCORR) {
			/* strange ... */
			return;
		}
		/* find next corridor position */
		dix = abs(xx - tx);
		diy = abs(yy - ty);

		/* do we have to change direction ? */
		if (dy && dix > diy) {
			int ddx = (xx > tx) ? -1 : 1;

			crm = &levl[xx + ddx][yy];
			if (!crm->typ || crm->typ == CORR || crm->typ == SCORR) {
				dx = ddx;
				dy = 0;
				continue;
			}
		} else if (dx && diy > dix) {
			int ddy = (yy > ty) ? -1 : 1;

			crm = &levl[xx][yy + ddy];
			if (!crm->typ || crm->typ == CORR || crm->typ == SCORR) {
				dy = ddy;
				dx = 0;
				continue;
			}
		}
		/* continue straight on? */
		crm = &levl[xx + dx][yy + dy];
		if (!crm->typ || crm->typ == CORR || crm->typ == SCORR)
			continue;

		/* no, what must we do now?? */
		if (dx) {
			dx = 0;
			dy = (ty < yy) ? -1 : 1;
			crm = &levl[xx + dx][yy + dy];
			if (!crm->typ || crm->typ == CORR || crm->typ == SCORR)
				continue;
			dy = -dy;
			continue;
		} else {
			dy = 0;
			dx = (tx < xx) ? -1 : 1;
			crm = &levl[xx + dx][yy + dy];
			if (!crm->typ || crm->typ == CORR || crm->typ == SCORR)
				continue;
			dx = -dx;
			continue;
		}
	}

	/* we succeeded in digging the corridor */
	dodoor(tt.x, tt.y, troom);

	if (smeq[a] < smeq[b])
		smeq[b] = smeq[a];
	else
		smeq[a] = smeq[b];
}

static void
make_niches(void)
{
	int             ct = rnd(nroom / 2 + 1);
	while (ct--)
		makeniche(FALSE);
}

static void
makevtele(void)
{
	makeniche(TRUE);
}

static void
makeniche(boolean with_trap)
{
	struct mkroom  *aroom;
	struct rm      *rm;
	int             vct = 8;
	coord           dd;
	int		dy, xx, yy;
	struct trap    *ttmp;

	if (doorindex < DOORMAX)
		while (vct--) {
			aroom = &rooms[rn2(nroom - 1)];
			if (aroom->rtype != 0)
				continue;	/* not an ordinary room */
			if (aroom->doorct == 1 && rn2(5))
				continue;
			if (rn2(2)) {
				dy = 1;
				dd = finddpos(aroom->lx, aroom->hy + 1, aroom->hx, aroom->hy + 1);
			} else {
				dy = -1;
				dd = finddpos(aroom->lx, aroom->ly - 1, aroom->hx, aroom->ly - 1);
			}
			xx = dd.x;
			yy = dd.y;
			if ((rm = &levl[xx][yy + dy])->typ)
				continue;
			if (with_trap || !rn2(4)) {
				rm->typ = SCORR;
				rm->scrsym = ' ';
				if (with_trap) {
					ttmp = maketrap(xx, yy + dy, TELEP_TRAP);
					ttmp->once = 1;
					make_engr_at(xx, yy - dy, "ad ae?ar um");
				}
				dosdoor(xx, yy, aroom, SDOOR);
			} else {
				rm->typ = CORR;
				rm->scrsym = CORR_SYM;
				if (rn2(7))
					dosdoor(xx, yy, aroom, rn2(5) ? SDOOR : DOOR);
				else {
					mksobj_at(SCR_TELEPORTATION, xx, yy + dy);
					if (!rn2(3))
						(void) mkobj_at(0, xx, yy + dy);
				}
			}
			return;
		}
}

/* make a trap somewhere (in croom if mazeflag = 0) */
void
mktrap(int num, int mazeflag, struct mkroom *croom)
{
	struct trap    *ttmp;
	int             kind, nopierc, nomimic, fakedoor, fakegold, tryct = 0;
	xchar           mx, my;

	if (!num || num >= TRAPNUM) {
		nopierc = (dlevel < 4) ? 1 : 0;
		nomimic = (dlevel < 9 || goldseen) ? 1 : 0;
		if (strchr(fut_geno, 'M'))
			nomimic = 1;
		kind = rn2(TRAPNUM - nopierc - nomimic);
		/* note: PIERC = 7, MIMIC = 8, TRAPNUM = 9 */
	} else
		kind = num;

	if (kind == MIMIC) {
		struct monst   *mtmp;

		fakedoor = (!rn2(3) && !mazeflag);
		fakegold = (!fakedoor && !rn2(2));
		if (fakegold)
			goldseen = TRUE;
		do {
			if (++tryct > 200)
				return;
			if (fakedoor) {
				/* note: fakedoor maybe on actual door */
				if (rn2(2)) {
					if (rn2(2))
						mx = croom->hx + 1;
					else
						mx = croom->lx - 1;
					my = somey();
				} else {
					if (rn2(2))
						my = croom->hy + 1;
					else
						my = croom->ly - 1;
					mx = somex();
				}
			} else if (mazeflag) {
				coord           mm;
				mm = mazexy();
				mx = mm.x;
				my = mm.y;
			} else {
				mx = somex();
				my = somey();
			}
		} while (m_at(mx, my) || levl[mx][my].typ == STAIRS);
		if ((mtmp = makemon(PM_MIMIC, mx, my)) != NULL) {
			mtmp->mimic = 1;
			mtmp->mappearance =
				fakegold ? '$' : fakedoor ? '+' :
				(mazeflag && rn2(2)) ? AMULET_SYM :
				"=/)%?![<>"[rn2(9)];
		}
		return;
	}
	do {
		if (++tryct > 200)
			return;
		if (mazeflag) {
			coord           mm;
			mm = mazexy();
			mx = mm.x;
			my = mm.y;
		} else {
			mx = somex();
			my = somey();
		}
	} while (t_at(mx, my) || levl[mx][my].typ == STAIRS);
	ttmp = maketrap(mx, my, kind);
	if (mazeflag && !rn2(10) && ttmp->ttyp < PIERC)
		ttmp->tseen = 1;
}