Source:NetHack 3.4.3/src/dbridge.c

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/*	SCCS Id: @(#)dbridge.c	3.4	2003/02/08	*/
/*	Copyright (c) 1989 by Jean-Christophe Collet		  */
/* NetHack may be freely redistributed.  See license for details. */

The NetHack General Public License applies to screenshots, source code and other content from NetHack.

This content was modified from the original NetHack source code distribution (by splitting up NetHack content between wiki pages, and possibly further editing). See the page history for a list of who changed it, and on what dates.

/*
* This file contains the drawbridge manipulation (create, open, close,
* destroy).
*
* Added comprehensive monster-handling, and the "entity" structure to
* deal with players as well. - 11/89
*/

#include "hack.h"

#ifdef OVLB
STATIC_DCL void FDECL(get_wall_for_db, (int *, int *));
STATIC_DCL struct entity *FDECL(e_at, (int, int));
STATIC_DCL void FDECL(m_to_e, (struct monst *, int, int, struct entity *));
STATIC_DCL void FDECL(u_to_e, (struct entity *));
STATIC_DCL void FDECL(set_entity, (int, int, struct entity *));
STATIC_DCL const char *FDECL(e_nam, (struct entity *));
#ifdef D_DEBUG
static const char *FDECL(Enam, (struct entity *)); /* unused */
#endif
STATIC_DCL const char *FDECL(E_phrase, (struct entity *, const char *));
STATIC_DCL boolean FDECL(e_survives_at, (struct entity *, int, int));
STATIC_DCL void FDECL(e_died, (struct entity *, int, int));
STATIC_DCL boolean FDECL(automiss, (struct entity *));
STATIC_DCL boolean FDECL(e_missed, (struct entity *, BOOLEAN_P));
STATIC_DCL boolean FDECL(e_jumps, (struct entity *));
STATIC_DCL void FDECL(do_entity, (struct entity *));
#endif /* OVLB */

is_pool

is_pool() takes two numbers, an x,y coordinate, and returns TRUE if the terrain at that coordinate is pool of water (even if it is under a drawbridge), FALSE otherwise.

#ifdef OVL0

boolean
is_pool(x,y)
int x,y;
{
schar ltyp;

if (!isok(x,y)) return FALSE;
ltyp = levl[x][y].typ;
if (ltyp == POOL || ltyp == MOAT || ltyp == WATER) return TRUE;
if (ltyp == DRAWBRIDGE_UP &&
	(levl[x][y].drawbridgemask & DB_UNDER) == DB_MOAT) return TRUE;
return FALSE;
}

is_lava

boolean
is_lava(x,y)
int x,y;
{
schar ltyp;

if (!isok(x,y)) return FALSE;
ltyp = levl[x][y].typ;
if (ltyp == LAVAPOOL
	|| (ltyp == DRAWBRIDGE_UP
	    && (levl[x][y].drawbridgemask & DB_UNDER) == DB_LAVA)) return TRUE;
return FALSE;
}

is_ice

boolean
is_ice(x,y)
int x,y;
{
schar ltyp;

if (!isok(x,y)) return FALSE;
ltyp = levl[x][y].typ;
if (ltyp == ICE
	|| (ltyp == DRAWBRIDGE_UP
	    && (levl[x][y].drawbridgemask & DB_UNDER) == DB_ICE)) return TRUE;
return FALSE;
}

#endif /* OVL0 */

is_drawbridge_wall

#ifdef OVL1

/*
* We want to know whether a wall (or a door) is the portcullis (passageway)
* of an eventual drawbridge.
*
* Return value:  the direction of the drawbridge.
*/

int
is_drawbridge_wall(x,y)
int x,y;
{
	struct rm *lev;

	lev = &levl[x][y];
	if (lev->typ != DOOR && lev->typ != DBWALL)
		return (-1);

	if (IS_DRAWBRIDGE(levl[x+1][y].typ) &&
	    (levl[x+1][y].drawbridgemask & DB_DIR) == DB_WEST)
		return (DB_WEST);
	if (IS_DRAWBRIDGE(levl[x-1][y].typ) &&
	    (levl[x-1][y].drawbridgemask & DB_DIR) == DB_EAST)
		return (DB_EAST);
	if (IS_DRAWBRIDGE(levl[x][y-1].typ) &&
	    (levl[x][y-1].drawbridgemask & DB_DIR) == DB_SOUTH)
		return (DB_SOUTH);
	if (IS_DRAWBRIDGE(levl[x][y+1].typ) &&
	    (levl[x][y+1].drawbridgemask & DB_DIR) == DB_NORTH)
		return (DB_NORTH);

	return (-1);
}

is_db_wall

/*
* Use is_db_wall where you want to verify that a
* drawbridge "wall" is UP in the location x, y
* (instead of UP or DOWN, as with is_drawbridge_wall).
*/
boolean
is_db_wall(x,y)
int x,y;
{
	return((boolean)( levl[x][y].typ == DBWALL ));
}

find_drawbridge

/*
* Return true with x,y pointing to the drawbridge if x,y initially indicate
* a drawbridge or drawbridge wall.
*/
boolean
find_drawbridge(x,y)
int *x,*y;
{
	int dir;

	if (IS_DRAWBRIDGE(levl[*x][*y].typ))
		return TRUE;
	dir = is_drawbridge_wall(*x,*y);
	if (dir >= 0) {
		switch(dir) {
			case DB_NORTH: (*y)++; break;
			case DB_SOUTH: (*y)--; break;
			case DB_EAST:  (*x)--; break;
			case DB_WEST:  (*x)++; break;
		}
		return TRUE;
	}
	return FALSE;
}

#endif /* OVL1 */

get_wall_for_db

#ifdef OVLB

/*
* Find the drawbridge wall associated with a drawbridge.
*/
STATIC_OVL void
get_wall_for_db(x,y)
int *x,*y;
{
	switch (levl[*x][*y].drawbridgemask & DB_DIR) {
		case DB_NORTH: (*y)--; break;
		case DB_SOUTH: (*y)++; break;
		case DB_EAST:  (*x)++; break;
		case DB_WEST:  (*x)--; break;
	}
}

create_drawbridge

/*
* Creation of a drawbridge at pos x,y.
*     dir is the direction.
*     flag must be put to TRUE if we want the drawbridge to be opened.
*/

boolean
create_drawbridge(x,y,dir,flag)
int x,y,dir;
boolean flag;
{
	int x2,y2;
	boolean horiz;
	boolean lava = levl[x][y].typ == LAVAPOOL; /* assume initialized map */

	x2 = x; y2 = y;
	switch(dir) {
		case DB_NORTH:
			horiz = TRUE;
			y2--;
			break;
		case DB_SOUTH:
			horiz = TRUE;
			y2++;
			break;
		case DB_EAST:
			horiz = FALSE;
			x2++;
			break;
		default:
			impossible("bad direction in create_drawbridge");
			/* fall through */
		case DB_WEST:
			horiz = FALSE;
			x2--;
			break;
	}
	if (!IS_WALL(levl[x2][y2].typ))
		return(FALSE);
	if (flag) {             /* We want the bridge open */
		levl[x][y].typ = DRAWBRIDGE_DOWN;
		levl[x2][y2].typ = DOOR;
		levl[x2][y2].doormask = D_NODOOR;
	} else {
		levl[x][y].typ = DRAWBRIDGE_UP;
		levl[x2][y2].typ = DBWALL;
		/* Drawbridges are non-diggable. */
		levl[x2][y2].wall_info = W_NONDIGGABLE;
	}
	levl[x][y].horizontal = !horiz;
	levl[x2][y2].horizontal = horiz;
	levl[x][y].drawbridgemask = dir;
	if(lava) levl[x][y].drawbridgemask |= DB_LAVA;
	return(TRUE);
}

e_at

struct entity {
	struct monst *emon;	  /* youmonst for the player */
	struct permonst *edata;   /* must be non-zero for record to be valid */
	int ex, ey;
};

#define ENTITIES 2

static NEARDATA struct entity occupants[ENTITIES];

STATIC_OVL
struct entity *
e_at(x, y)
int x, y;
{
	int entitycnt;

	for (entitycnt = 0; entitycnt < ENTITIES; entitycnt++)
		if ((occupants[entitycnt].edata) &&
		    (occupants[entitycnt].ex == x) &&
		    (occupants[entitycnt].ey == y))
			break;
#ifdef D_DEBUG
	pline("entitycnt = %d", entitycnt);
	wait_synch();
#endif
	return((entitycnt == ENTITIES)?
	       (struct entity *)0 : &(occupants[entitycnt]));
}

m_to_e

STATIC_OVL void
m_to_e(mtmp, x, y, etmp)
struct monst *mtmp;
int x, y;
struct entity *etmp;
{
	etmp->emon = mtmp;
	if (mtmp) {
		etmp->ex = x;
		etmp->ey = y;
		if (mtmp->wormno && (x != mtmp->mx || y != mtmp->my))
			etmp->edata = &mons[PM_LONG_WORM_TAIL];
		else
			etmp->edata = mtmp->data;
	} else
		etmp->edata = (struct permonst *)0;
}

u_to_e

STATIC_OVL void
u_to_e(etmp)
struct entity *etmp;
{
	etmp->emon = &youmonst;
	etmp->ex = u.ux;
	etmp->ey = u.uy;
	etmp->edata = youmonst.data;
}

set_entity

STATIC_OVL void
set_entity(x, y, etmp)
int x, y;
struct entity *etmp;
{
	if ((x == u.ux) && (y == u.uy))
		u_to_e(etmp);
	else if (MON_AT(x, y))
		m_to_e(m_at(x, y), x, y, etmp);
	else
		etmp->edata = (struct permonst *)0;
}

e_nam

#define is_u(etmp) (etmp->emon == &youmonst)
#define e_canseemon(etmp) (is_u(etmp) ? (boolean)TRUE : canseemon(etmp->emon))

/*
* e_strg is a utility routine which is not actually in use anywhere, since
* the specialized routines below suffice for all current purposes.
*/

/* #define e_strg(etmp, func) (is_u(etmp)? (char *)0 : func(etmp->emon)) */

STATIC_OVL const char *
e_nam(etmp)
struct entity *etmp;
{
	return(is_u(etmp)? "you" : mon_nam(etmp->emon));
}

Enam

#ifdef D_DEBUG
/*
* Enam is another unused utility routine:  E_phrase is preferable.
*/

static const char *
Enam(etmp)
struct entity *etmp;
{
	return(is_u(etmp)? "You" : Monnam(etmp->emon));
}
#endif /* D_DEBUG */

E_phrase

/*
* Generates capitalized entity name, makes 2nd -> 3rd person conversion on
* verb, where necessary.
*/

STATIC_OVL const char *
E_phrase(etmp, verb)
struct entity *etmp;
const char *verb;
{
	static char wholebuf[80];

	Strcpy(wholebuf, is_u(etmp) ? "You" : Monnam(etmp->emon));
	if (!*verb) return(wholebuf);
	Strcat(wholebuf, " ");
	if (is_u(etmp))
	    Strcat(wholebuf, verb);
	else
	    Strcat(wholebuf, vtense((char *)0, verb));
	return(wholebuf);
}

e_survives_at

/*
* Simple-minded "can it be here?" routine
*/

STATIC_OVL boolean
e_survives_at(etmp, x, y)
struct entity *etmp;
int x, y;
{
	if (noncorporeal(etmp->edata))
		return(TRUE);
	if (is_pool(x, y))
		return (boolean)((is_u(etmp) &&
				(Wwalking || Amphibious || Swimming ||
				Flying || Levitation)) ||
			is_swimmer(etmp->edata) || is_flyer(etmp->edata) ||
			is_floater(etmp->edata));
	/* must force call to lava_effects in e_died if is_u */
	if (is_lava(x, y))
		return (boolean)((is_u(etmp) && (Levitation || Flying)) ||
			    likes_lava(etmp->edata) || is_flyer(etmp->edata));
	if (is_db_wall(x, y))
		return((boolean)(is_u(etmp) ? Passes_walls :
			passes_walls(etmp->edata)));
	return(TRUE);
}

e_died

STATIC_OVL void
e_died(etmp, dest, how)
struct entity *etmp;
int dest, how;
{
	if (is_u(etmp)) {
		if (how == DROWNING) {
			killer = 0;	/* drown() sets its own killer */
			(void) drown();
		} else if (how == BURNING) {
			killer = 0;	/* lava_effects() sets its own killer */
			(void) lava_effects();
		} else {
			coord xy;

			/* use more specific killer if specified */
			if (!killer) {
			    killer_format = KILLED_BY_AN;
			    killer = "falling drawbridge";
			}
			done(how);
			/* So, you didn't die */
			if (!e_survives_at(etmp, etmp->ex, etmp->ey)) {
			    if (enexto(&xy, etmp->ex, etmp->ey, etmp->edata)) {
				pline("A %s force teleports you away...",
				      Hallucination ? "normal" : "strange");
				teleds(xy.x, xy.y, FALSE);
			    }
			    /* otherwise on top of the drawbridge is the
			     * only viable spot in the dungeon, so stay there
			     */
			}
		}
		/* we might have crawled out of the moat to survive */
		etmp->ex = u.ux,  etmp->ey = u.uy;
	} else {
		int entitycnt;

		killer = 0;
		/* fake "digested to death" damage-type suppresses corpse */
#define mk_message(dest) ((dest & 1) ? "" : (char *)0)
#define mk_corpse(dest)  ((dest & 2) ? AD_DGST : AD_PHYS)
		/* if monsters are moving, one of them caused the destruction */
		if (flags.mon_moving)
		    monkilled(etmp->emon, mk_message(dest), mk_corpse(dest));
		else		/* you caused it */
		    xkilled(etmp->emon, dest);
		etmp->edata = (struct permonst *)0;

		/* dead long worm handling */
		for (entitycnt = 0; entitycnt < ENTITIES; entitycnt++) {
		    if (etmp != &(occupants[entitycnt]) &&
			etmp->emon == occupants[entitycnt].emon)
			occupants[entitycnt].edata = (struct permonst *)0;
		}
#undef mk_message
#undef mk_corpse
	}
}

automiss

/*
* These are never directly affected by a bridge or portcullis.
*/

STATIC_OVL boolean
automiss(etmp)
struct entity *etmp;
{
	return (boolean)((is_u(etmp) ? Passes_walls :
			passes_walls(etmp->edata)) || noncorporeal(etmp->edata));
}

e_missed

/*
* Does falling drawbridge or portcullis miss etmp?
*/

STATIC_OVL boolean
e_missed(etmp, chunks)
struct entity *etmp;
boolean chunks;
{
	int misses;

#ifdef D_DEBUG
	if (chunks)
		pline("Do chunks miss?");
#endif
	if (automiss(etmp))
		return(TRUE);

	if (is_flyer(etmp->edata) &&
	    (is_u(etmp)? !Sleeping :
	     (etmp->emon->mcanmove && !etmp->emon->msleeping)))
						 /* flying requires mobility */
		misses = 5;	/* out of 8 */
	else if (is_floater(etmp->edata) ||
		    (is_u(etmp) && Levitation))	 /* doesn't require mobility */
		misses = 3;
	else if (chunks && is_pool(etmp->ex, etmp->ey))
		misses = 2;				    /* sitting ducks */
	else
		misses = 0;

	if (is_db_wall(etmp->ex, etmp->ey))
		misses -= 3;				    /* less airspace */

#ifdef D_DEBUG
	pline("Miss chance = %d (out of 8)", misses);
#endif

	return((boolean)((misses >= rnd(8))? TRUE : FALSE));
}

e_jumps

/*
* Can etmp jump from death?
*/

STATIC_OVL boolean
e_jumps(etmp)
struct entity *etmp;
{
	int tmp = 4;		/* out of 10 */

	if (is_u(etmp)? (Sleeping || Fumbling) :
		        (!etmp->emon->mcanmove || etmp->emon->msleeping ||
			 !etmp->edata->mmove   || etmp->emon->wormno))
		return(FALSE);

	if (is_u(etmp)? Confusion : etmp->emon->mconf)
		tmp -= 2;

	if (is_u(etmp)? Stunned : etmp->emon->mstun)
		tmp -= 3;

	if (is_db_wall(etmp->ex, etmp->ey))
		tmp -= 2;			    /* less room to maneuver */

#ifdef D_DEBUG
	pline("%s to jump (%d chances in 10)", E_phrase(etmp, "try"), tmp);
#endif
	return((boolean)((tmp >= rnd(10))? TRUE : FALSE));
}

do_entity

STATIC_OVL void
do_entity(etmp)
struct entity *etmp;
{
	int newx, newy, at_portcullis, oldx, oldy;
	boolean must_jump = FALSE, relocates = FALSE, e_inview;
	struct rm *crm;

	if (!etmp->edata)
		return;

	e_inview = e_canseemon(etmp);
	oldx = etmp->ex;
	oldy = etmp->ey;
	at_portcullis = is_db_wall(oldx, oldy);
	crm = &levl[oldx][oldy];

	if (automiss(etmp) && e_survives_at(etmp, oldx, oldy)) {
		if (e_inview && (at_portcullis || IS_DRAWBRIDGE(crm->typ)))
			pline_The("%s passes through %s!",
			      at_portcullis ? "portcullis" : "drawbridge",
			      e_nam(etmp));
		if (is_u(etmp)) spoteffects(FALSE);
		return;
	}
	if (e_missed(etmp, FALSE)) {
		if (at_portcullis)
			pline_The("portcullis misses %s!",
			      e_nam(etmp));
#ifdef D_DEBUG
		else
			pline_The("drawbridge misses %s!",
			      e_nam(etmp));
#endif
		if (e_survives_at(etmp, oldx, oldy))
			return;
		else {
#ifdef D_DEBUG
			pline("Mon can't survive here");
#endif
			if (at_portcullis)
				must_jump = TRUE;
			else
				relocates = TRUE; /* just ride drawbridge in */
		}
	} else {
		if (crm->typ == DRAWBRIDGE_DOWN) {
			pline("%s crushed underneath the drawbridge.",
			      E_phrase(etmp, "are"));		  /* no jump */
			e_died(etmp, e_inview? 3 : 2, CRUSHING);/* no corpse */
			return;   /* Note: Beyond this point, we know we're  */
		}		  /* not at an opened drawbridge, since all  */
		must_jump = TRUE; /* *missable* creatures survive on the     */
	}			  /* square, and all the unmissed ones die.  */
	if (must_jump) {
	    if (at_portcullis) {
		if (e_jumps(etmp)) {
		    relocates = TRUE;
#ifdef D_DEBUG
		    pline("Jump succeeds!");
#endif
		} else {
		    if (e_inview)
			pline("%s crushed by the falling portcullis!",
			      E_phrase(etmp, "are"));
		    else if (flags.soundok)
			You_hear("a crushing sound.");
		    e_died(etmp, e_inview? 3 : 2, CRUSHING);
		    /* no corpse */
		    return;
		}
	    } else { /* tries to jump off bridge to original square */
		relocates = !e_jumps(etmp);
#ifdef D_DEBUG
		pline("Jump %s!", (relocates)? "fails" : "succeeds");
#endif
	    }
	}

/*
* Here's where we try to do relocation.  Assumes that etmp is not arriving
* at the portcullis square while the drawbridge is falling, since this square
* would be inaccessible (i.e. etmp started on drawbridge square) or
* unnecessary (i.e. etmp started here) in such a situation.
*/
#ifdef D_DEBUG
	pline("Doing relocation.");
#endif
	newx = oldx;
	newy = oldy;
	(void)find_drawbridge(&newx, &newy);
	if ((newx == oldx) && (newy == oldy))
		get_wall_for_db(&newx, &newy);
#ifdef D_DEBUG
	pline("Checking new square for occupancy.");
#endif
	if (relocates && (e_at(newx, newy))) {

/*
* Standoff problem:  one or both entities must die, and/or both switch
* places.  Avoid infinite recursion by checking first whether the other
* entity is staying put.  Clean up if we happen to move/die in recursion.
*/
		struct entity *other;

		other = e_at(newx, newy);
#ifdef D_DEBUG
		pline("New square is occupied by %s", e_nam(other));
#endif
		if (e_survives_at(other, newx, newy) && automiss(other)) {
			relocates = FALSE;	      /* "other" won't budge */
#ifdef D_DEBUG
			pline("%s suicide.", E_phrase(etmp, "commit"));
#endif
		} else {

#ifdef D_DEBUG
			pline("Handling %s", e_nam(other));
#endif
			while ((e_at(newx, newy) != 0) &&
			       (e_at(newx, newy) != etmp))
				do_entity(other);
#ifdef D_DEBUG
			pline("Checking existence of %s", e_nam(etmp));
			wait_synch();
#endif
			if (e_at(oldx, oldy) != etmp) {
#ifdef D_DEBUG
			    pline("%s moved or died in recursion somewhere",
				  E_phrase(etmp, "have"));
			    wait_synch();
#endif
			    return;
			}
		}
	}
	if (relocates && !e_at(newx, newy)) {/* if e_at() entity = worm tail */
#ifdef D_DEBUG
		pline("Moving %s", e_nam(etmp));
#endif
		if (!is_u(etmp)) {
			remove_monster(etmp->ex, etmp->ey);
			place_monster(etmp->emon, newx, newy);
			update_monster_region(etmp->emon);
		} else {
			u.ux = newx;
			u.uy = newy;
		}
		etmp->ex = newx;
		etmp->ey = newy;
		e_inview = e_canseemon(etmp);
	}
#ifdef D_DEBUG
	pline("Final disposition of %s", e_nam(etmp));
	wait_synch();
#endif
	if (is_db_wall(etmp->ex, etmp->ey)) {
#ifdef D_DEBUG
		pline("%s in portcullis chamber", E_phrase(etmp, "are"));
		wait_synch();
#endif
		if (e_inview) {
			if (is_u(etmp)) {
				You("tumble towards the closed portcullis!");
				if (automiss(etmp))
					You("pass through it!");
				else
					pline_The("drawbridge closes in...");
			} else
				pline("%s behind the drawbridge.",
				      E_phrase(etmp, "disappear"));
		}
		if (!e_survives_at(etmp, etmp->ex, etmp->ey)) {
			killer_format = KILLED_BY_AN;
			killer = "closing drawbridge";
			e_died(etmp, 0, CRUSHING);	       /* no message */
			return;
		}
#ifdef D_DEBUG
		pline("%s in here", E_phrase(etmp, "survive"));
#endif
	} else {
#ifdef D_DEBUG
		pline("%s on drawbridge square", E_phrase(etmp, "are"));
#endif
		if (is_pool(etmp->ex, etmp->ey) && !e_inview)
			if (flags.soundok)
				You_hear("a splash.");
		if (e_survives_at(etmp, etmp->ex, etmp->ey)) {
			if (e_inview && !is_flyer(etmp->edata) &&
			    !is_floater(etmp->edata))
				pline("%s from the bridge.",
				      E_phrase(etmp, "fall"));
			return;
		}
#ifdef D_DEBUG
		pline("%s cannot survive on the drawbridge square",Enam(etmp));
#endif
		if (is_pool(etmp->ex, etmp->ey) || is_lava(etmp->ex, etmp->ey))
		    if (e_inview && !is_u(etmp)) {
			/* drown() will supply msgs if nec. */
			boolean lava = is_lava(etmp->ex, etmp->ey);

			if (Hallucination)
			    pline("%s the %s and disappears.",
				  E_phrase(etmp, "drink"),
				  lava ? "lava" : "moat");
			else
			    pline("%s into the %s.",
				  E_phrase(etmp, "fall"),
				  lava ? "lava" : "moat");
		    }
		killer_format = NO_KILLER_PREFIX;
		killer = "fell from a drawbridge";
		e_died(etmp, e_inview ? 3 : 2,      /* CRUSHING is arbitrary */
		       (is_pool(etmp->ex, etmp->ey)) ? DROWNING :
		       (is_lava(etmp->ex, etmp->ey)) ? BURNING :
						       CRUSHING); /*no corpse*/
		return;
	}
}

close_drawbridge

/*
* Close the drawbridge located at x,y
*/

void
close_drawbridge(x,y)
int x,y;
{
	register struct rm *lev1, *lev2;
	struct trap *t;
	int x2, y2;

	lev1 = &levl[x][y];
	if (lev1->typ != DRAWBRIDGE_DOWN) return;
	x2 = x; y2 = y;
	get_wall_for_db(&x2,&y2);
	if (cansee(x,y) || cansee(x2,y2))
		You("see a drawbridge %s up!",
		    (((u.ux == x || u.uy == y) && !Underwater) ||
		     distu(x2,y2) < distu(x,y)) ? "coming" : "going");
	lev1->typ = DRAWBRIDGE_UP;
	lev2 = &levl[x2][y2];
	lev2->typ = DBWALL;
	switch (lev1->drawbridgemask & DB_DIR) {
		case DB_NORTH:
		case DB_SOUTH:
			lev2->horizontal = TRUE;
			break;
		case DB_WEST:
		case DB_EAST:
			lev2->horizontal = FALSE;
			break;
	}
	lev2->wall_info = W_NONDIGGABLE;
	set_entity(x, y, &(occupants[0]));
	set_entity(x2, y2, &(occupants[1]));
	do_entity(&(occupants[0]));		/* Do set_entity after first */
	set_entity(x2, y2, &(occupants[1]));	/* do_entity for worm tail */
	do_entity(&(occupants[1]));
	if(OBJ_AT(x,y) && flags.soundok)
	    You_hear("smashing and crushing.");
	(void) revive_nasty(x,y,(char *)0);
	(void) revive_nasty(x2,y2,(char *)0);
	delallobj(x, y);
	delallobj(x2, y2);
	if ((t = t_at(x, y)) != 0) deltrap(t);
	if ((t = t_at(x2, y2)) != 0) deltrap(t);
	newsym(x, y);
	newsym(x2, y2);
	block_point(x2,y2);	/* vision */
}

open_drawbridge

/*
* Open the drawbridge located at x,y
*/

void
open_drawbridge(x,y)
int x,y;
{
	register struct rm *lev1, *lev2;
	struct trap *t;
	int x2, y2;

	lev1 = &levl[x][y];
	if (lev1->typ != DRAWBRIDGE_UP) return;
	x2 = x; y2 = y;
	get_wall_for_db(&x2,&y2);
	if (cansee(x,y) || cansee(x2,y2))
		You("see a drawbridge %s down!",
		    (distu(x2,y2) < distu(x,y)) ? "going" : "coming");
	lev1->typ = DRAWBRIDGE_DOWN;
	lev2 = &levl[x2][y2];
	lev2->typ = DOOR;
	lev2->doormask = D_NODOOR;
	set_entity(x, y, &(occupants[0]));
	set_entity(x2, y2, &(occupants[1]));
	do_entity(&(occupants[0]));		/* do set_entity after first */
	set_entity(x2, y2, &(occupants[1]));	/* do_entity for worm tails */
	do_entity(&(occupants[1]));
	(void) revive_nasty(x,y,(char *)0);
	delallobj(x, y);
	if ((t = t_at(x, y)) != 0) deltrap(t);
	if ((t = t_at(x2, y2)) != 0) deltrap(t);
	newsym(x, y);
	newsym(x2, y2);
	unblock_point(x2,y2);	/* vision */
	if (Is_stronghold(&u.uz)) u.uevent.uopened_dbridge = TRUE;
}

destroy_drawbridge

/*
* Let's destroy the drawbridge located at x,y
*/

void
destroy_drawbridge(x,y)
int x,y;
{
	register struct rm *lev1, *lev2;
	struct trap *t;
	int x2, y2;
	boolean e_inview;
	struct entity *etmp1 = &(occupants[0]), *etmp2 = &(occupants[1]);

	lev1 = &levl[x][y];
	if (!IS_DRAWBRIDGE(lev1->typ))
		return;
	x2 = x; y2 = y;
	get_wall_for_db(&x2,&y2);
	lev2 = &levl[x2][y2];
	if ((lev1->drawbridgemask & DB_UNDER) == DB_MOAT ||
	    (lev1->drawbridgemask & DB_UNDER) == DB_LAVA) {
		struct obj *otmp;
		boolean lava = (lev1->drawbridgemask & DB_UNDER) == DB_LAVA;
		if (lev1->typ == DRAWBRIDGE_UP) {
			if (cansee(x2,y2))
			    pline_The("portcullis of the drawbridge falls into the %s!",
				  lava ? "lava" : "moat");
			else if (flags.soundok)
				You_hear("a loud *SPLASH*!");
		} else {
			if (cansee(x,y))
			    pline_The("drawbridge collapses into the %s!",
				  lava ? "lava" : "moat");
			else if (flags.soundok)
				You_hear("a loud *SPLASH*!");
		}
		lev1->typ = lava ? LAVAPOOL : MOAT;
		lev1->drawbridgemask = 0;
		if ((otmp = sobj_at(BOULDER,x,y)) != 0) {
		    obj_extract_self(otmp);
		    (void) flooreffects(otmp,x,y,"fall");
		}
	} else {
		if (cansee(x,y))
			pline_The("drawbridge disintegrates!");
		else
			You_hear("a loud *CRASH*!");
		lev1->typ =
			((lev1->drawbridgemask & DB_ICE) ? ICE : ROOM);
		lev1->icedpool =
			((lev1->drawbridgemask & DB_ICE) ? ICED_MOAT : 0);
	}
	wake_nearto(x, y, 500);
	lev2->typ = DOOR;
	lev2->doormask = D_NODOOR;
	if ((t = t_at(x, y)) != 0) deltrap(t);
	if ((t = t_at(x2, y2)) != 0) deltrap(t);
	newsym(x,y);
	newsym(x2,y2);
	if (!does_block(x2,y2,lev2)) unblock_point(x2,y2);	/* vision */
	if (Is_stronghold(&u.uz)) u.uevent.uopened_dbridge = TRUE;

	set_entity(x2, y2, etmp2); /* currently only automissers can be here */
	if (etmp2->edata) {
		e_inview = e_canseemon(etmp2);
		if (!automiss(etmp2)) {
			if (e_inview)
				pline("%s blown apart by flying debris.",
				      E_phrase(etmp2, "are"));
			killer_format = KILLED_BY_AN;
			killer = "exploding drawbridge";
			e_died(etmp2, e_inview? 3 : 2, CRUSHING); /*no corpse*/
		}	     /* nothing which is vulnerable can survive this */
	}
	set_entity(x, y, etmp1);
	if (etmp1->edata) {
		e_inview = e_canseemon(etmp1);
		if (e_missed(etmp1, TRUE)) {
#ifdef D_DEBUG
			pline("%s spared!", E_phrase(etmp1, "are"));
#endif
		} else {
			if (e_inview) {
			    if (!is_u(etmp1) && Hallucination)
				pline("%s into some heavy metal!",
				      E_phrase(etmp1, "get"));
			    else
				pline("%s hit by a huge chunk of metal!",
				      E_phrase(etmp1, "are"));
			} else {
			    if (flags.soundok && !is_u(etmp1) && !is_pool(x,y))
				You_hear("a crushing sound.");
#ifdef D_DEBUG
			    else
				pline("%s from shrapnel",
				      E_phrase(etmp1, "die"));
#endif
			}
			killer_format = KILLED_BY_AN;
			killer = "collapsing drawbridge";
			e_died(etmp1, e_inview? 3 : 2, CRUSHING); /*no corpse*/
			if(lev1->typ == MOAT) do_entity(etmp1);
		}
	}
}

#endif /* OVLB */

/*dbridge.c*/