Source:NetHack 3.6.0/src/detect.c

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Below is the full text to detect.c from the source code of NetHack 3.6.0. To link to a particular line, write [[Source:NetHack 3.6.0/src/detect.c#line123]], for example.

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 /* NetHack 3.6	detect.c	$NHDT-Date: 1446369464 2015/11/01 09:17:44 $  $NHDT-Branch: master $:$NHDT-Revision: 1.61 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /* NetHack may be freely redistributed.  See license for details. */
 
 /*
  * Detection routines, including crystal ball, magic mapping, and search
  * command.
  */
 
 #include "hack.h"
 #include "artifact.h"
 
 extern boolean known; /* from read.c */
 
 STATIC_DCL void FDECL(do_dknown_of, (struct obj *));
 STATIC_DCL boolean FDECL(check_map_spot, (int, int, CHAR_P, unsigned));
 STATIC_DCL boolean FDECL(clear_stale_map, (CHAR_P, unsigned));
 STATIC_DCL void FDECL(sense_trap, (struct trap *, XCHAR_P, XCHAR_P, int));
 STATIC_DCL int FDECL(detect_obj_traps, (struct obj *, BOOLEAN_P, int));
 STATIC_DCL void FDECL(show_map_spot, (int, int));
 STATIC_PTR void FDECL(findone, (int, int, genericptr_t));
 STATIC_PTR void FDECL(openone, (int, int, genericptr_t));
 

o_in

 /* Recursively search obj for an object in class oclass and return 1st found
  */
 struct obj *
 o_in(obj, oclass)
 struct obj *obj;
 char oclass;
 {
     register struct obj *otmp;
     struct obj *temp;
 
     if (obj->oclass == oclass)
         return obj;
 
     if (Has_contents(obj)) {
         for (otmp = obj->cobj; otmp; otmp = otmp->nobj)
             if (otmp->oclass == oclass)
                 return otmp;
             else if (Has_contents(otmp) && (temp = o_in(otmp, oclass)))
                 return temp;
     }
     return (struct obj *) 0;
 }
 

o_material

 /* Recursively search obj for an object made of specified material.
  * Return first found.
  */
 struct obj *
 o_material(obj, material)
 struct obj *obj;
 unsigned material;
 {
     register struct obj *otmp;
     struct obj *temp;
 
     if (objects[obj->otyp].oc_material == material)
         return obj;
 
     if (Has_contents(obj)) {
         for (otmp = obj->cobj; otmp; otmp = otmp->nobj)
             if (objects[otmp->otyp].oc_material == material)
                 return otmp;
             else if (Has_contents(otmp)
                      && (temp = o_material(otmp, material)))
                 return temp;
     }
     return (struct obj *) 0;
 }
 

do_dknown_of

 STATIC_OVL void
 do_dknown_of(obj)
 struct obj *obj;
 {
     struct obj *otmp;
 
     obj->dknown = 1;
     if (Has_contents(obj)) {
         for (otmp = obj->cobj; otmp; otmp = otmp->nobj)
             do_dknown_of(otmp);
     }
 }
 

check_map_spot

 /* Check whether the location has an outdated object displayed on it. */
 STATIC_OVL boolean
 check_map_spot(x, y, oclass, material)
 int x, y;
 char oclass;
 unsigned material;
 {
     int glyph;
     register struct obj *otmp;
     register struct monst *mtmp;
 
     glyph = glyph_at(x, y);
     if (glyph_is_object(glyph)) {
         /* there's some object shown here */
         if (oclass == ALL_CLASSES) {
             return (boolean) !(level.objects[x][y] /* stale if nothing here */
                                || ((mtmp = m_at(x, y)) != 0 && mtmp->minvent));
         } else {
             if (material
                 && objects[glyph_to_obj(glyph)].oc_material == material) {
                 /* object shown here is of interest because material matches */
                 for (otmp = level.objects[x][y]; otmp; otmp = otmp->nexthere)
                     if (o_material(otmp, GOLD))
                         return FALSE;
                 /* didn't find it; perhaps a monster is carrying it */
                 if ((mtmp = m_at(x, y)) != 0) {
                     for (otmp = mtmp->minvent; otmp; otmp = otmp->nobj)
                         if (o_material(otmp, GOLD))
                             return FALSE;
                 }
                 /* detection indicates removal of this object from the map */
                 return TRUE;
             }
             if (oclass && objects[glyph_to_obj(glyph)].oc_class == oclass) {
                 /* obj shown here is of interest because its class matches */
                 for (otmp = level.objects[x][y]; otmp; otmp = otmp->nexthere)
                     if (o_in(otmp, oclass))
                         return FALSE;
                 /* didn't find it; perhaps a monster is carrying it */
                 if ((mtmp = m_at(x, y)) != 0) {
                     for (otmp = mtmp->minvent; otmp; otmp = otmp->nobj)
                         if (o_in(otmp, oclass))
                             return FALSE;
                 }
                 /* detection indicates removal of this object from the map */
                 return TRUE;
             }
         }
     }
     return FALSE;
 }
 

clear_stale_map

 /*
  * When doing detection, remove stale data from the map display (corpses
  * rotted away, objects carried away by monsters, etc) so that it won't
  * reappear after the detection has completed.  Return true if noticeable
  * change occurs.
  */
 STATIC_OVL boolean
 clear_stale_map(oclass, material)
 char oclass;
 unsigned material;
 {
     register int zx, zy;
     boolean change_made = FALSE;
 
     for (zx = 1; zx < COLNO; zx++)
         for (zy = 0; zy < ROWNO; zy++)
             if (check_map_spot(zx, zy, oclass, material)) {
                 unmap_object(zx, zy);
                 change_made = TRUE;
             }
 
     return change_made;
 }
 

gold_detect

 /* look for gold, on the floor or in monsters' possession */
 int
 gold_detect(sobj)
 register struct obj *sobj;
 {
     register struct obj *obj;
     register struct monst *mtmp;
     struct obj *temp;
     boolean stale;
 
     known = stale =
         clear_stale_map(COIN_CLASS, (unsigned) (sobj->blessed ? GOLD : 0));
 
     /* look for gold carried by monsters (might be in a container) */
     for (mtmp = fmon; mtmp; mtmp = mtmp->nmon) {
         if (DEADMONSTER(mtmp))
             continue; /* probably not needed in this case but... */
         if (findgold(mtmp->minvent) || monsndx(mtmp->data) == PM_GOLD_GOLEM) {
             known = TRUE;
             goto outgoldmap; /* skip further searching */
         } else
             for (obj = mtmp->minvent; obj; obj = obj->nobj)
                 if (sobj->blessed && o_material(obj, GOLD)) {
                     known = TRUE;
                     goto outgoldmap;
                 } else if (o_in(obj, COIN_CLASS)) {
                     known = TRUE;
                     goto outgoldmap; /* skip further searching */
                 }
     }
 
     /* look for gold objects */
     for (obj = fobj; obj; obj = obj->nobj) {
         if (sobj->blessed && o_material(obj, GOLD)) {
             known = TRUE;
             if (obj->ox != u.ux || obj->oy != u.uy)
                 goto outgoldmap;
         } else if (o_in(obj, COIN_CLASS)) {
             known = TRUE;
             if (obj->ox != u.ux || obj->oy != u.uy)
                 goto outgoldmap;
         }
     }
 
     if (!known) {
         /* no gold found on floor or monster's inventory.
            adjust message if you have gold in your inventory */
         if (sobj) {
             char buf[BUFSZ];
             if (youmonst.data == &mons[PM_GOLD_GOLEM]) {
                 Sprintf(buf, "You feel like a million %s!", currency(2L));
             } else if (hidden_gold() || money_cnt(invent))
                 Strcpy(buf,
                    "You feel worried about your future financial situation.");
             else
                 Strcpy(buf, "You feel materially poor.");
             strange_feeling(sobj, buf);
         }
         return 1;
     }
     /* only under me - no separate display required */
     if (stale)
         docrt();
     You("notice some gold between your %s.", makeplural(body_part(FOOT)));
     return 0;
 
 outgoldmap:
     cls();
 
     iflags.save_uinwater = u.uinwater, iflags.save_uburied = u.uburied;
     u.uinwater = u.uburied = 0;
     /* Discover gold locations. */
     for (obj = fobj; obj; obj = obj->nobj) {
         if (sobj->blessed && (temp = o_material(obj, GOLD))) {
             if (temp != obj) {
                 temp->ox = obj->ox;
                 temp->oy = obj->oy;
             }
             map_object(temp, 1);
         } else if ((temp = o_in(obj, COIN_CLASS))) {
             if (temp != obj) {
                 temp->ox = obj->ox;
                 temp->oy = obj->oy;
             }
             map_object(temp, 1);
         }
     }
     for (mtmp = fmon; mtmp; mtmp = mtmp->nmon) {
         if (DEADMONSTER(mtmp))
             continue; /* probably overkill here */
         if (findgold(mtmp->minvent) || monsndx(mtmp->data) == PM_GOLD_GOLEM) {
             struct obj gold;
             gold = zeroobj; /* ensure oextra is cleared too */
             gold.otyp = GOLD_PIECE;
             gold.ox = mtmp->mx;
             gold.oy = mtmp->my;
             map_object(&gold, 1);
         } else
             for (obj = mtmp->minvent; obj; obj = obj->nobj)
                 if (sobj->blessed && (temp = o_material(obj, GOLD))) {
                     temp->ox = mtmp->mx;
                     temp->oy = mtmp->my;
                     map_object(temp, 1);
                     break;
                 } else if ((temp = o_in(obj, COIN_CLASS))) {
                     temp->ox = mtmp->mx;
                     temp->oy = mtmp->my;
                     map_object(temp, 1);
                     break;
                 }
     }
     newsym(u.ux, u.uy);
     u.uinwater = iflags.save_uinwater, u.uburied = iflags.save_uburied;
     You_feel("very greedy, and sense gold!");
     exercise(A_WIS, TRUE);
     display_nhwindow(WIN_MAP, TRUE);
     docrt();
     if (Underwater)
         under_water(2);
     if (u.uburied)
         under_ground(2);
     return 0;
 }
 

food_detect

 /* returns 1 if nothing was detected   */
 /* returns 0 if something was detected */
 int
 food_detect(sobj)
 register struct obj *sobj;
 {
     register struct obj *obj;
     register struct monst *mtmp;
     register int ct = 0, ctu = 0;
     boolean confused = (Confusion || (sobj && sobj->cursed)), stale;
     char oclass = confused ? POTION_CLASS : FOOD_CLASS;
     const char *what = confused ? something : "food";
 
     stale = clear_stale_map(oclass, 0);
 
     for (obj = fobj; obj; obj = obj->nobj)
         if (o_in(obj, oclass)) {
             if (obj->ox == u.ux && obj->oy == u.uy)
                 ctu++;
             else
                 ct++;
         }
     for (mtmp = fmon; mtmp && !ct; mtmp = mtmp->nmon) {
         /* no DEADMONSTER(mtmp) check needed since dmons never have inventory
          */
         for (obj = mtmp->minvent; obj; obj = obj->nobj)
             if (o_in(obj, oclass)) {
                 ct++;
                 break;
             }
     }
 
     if (!ct && !ctu) {
         known = stale && !confused;
         if (stale) {
             docrt();
             You("sense a lack of %s nearby.", what);
             if (sobj && sobj->blessed) {
                 if (!u.uedibility)
                     Your("%s starts to tingle.", body_part(NOSE));
                 u.uedibility = 1;
             }
         } else if (sobj) {
             char buf[BUFSZ];
             Sprintf(buf, "Your %s twitches%s.", body_part(NOSE),
                     (sobj->blessed && !u.uedibility)
                         ? " then starts to tingle"
                         : "");
             if (sobj->blessed && !u.uedibility) {
                 boolean savebeginner = flags.beginner;
 
                 flags.beginner = FALSE; /* prevent non-delivery of message */
                 strange_feeling(sobj, buf);
                 flags.beginner = savebeginner;
                 u.uedibility = 1;
             } else
                 strange_feeling(sobj, buf);
         }
         return !stale;
     } else if (!ct) {
         known = TRUE;
         You("%s %s nearby.", sobj ? "smell" : "sense", what);
         if (sobj && sobj->blessed) {
             if (!u.uedibility)
                 pline("Your %s starts to tingle.", body_part(NOSE));
             u.uedibility = 1;
         }
     } else {
         struct obj *temp;
         known = TRUE;
         cls();
         iflags.save_uinwater = u.uinwater, iflags.save_uburied = u.uburied;
         u.uinwater = u.uburied = 0;
         for (obj = fobj; obj; obj = obj->nobj)
             if ((temp = o_in(obj, oclass)) != 0) {
                 if (temp != obj) {
                     temp->ox = obj->ox;
                     temp->oy = obj->oy;
                 }
                 map_object(temp, 1);
             }
         for (mtmp = fmon; mtmp; mtmp = mtmp->nmon)
             /* no DEADMONSTER(mtmp) check needed since dmons never have
              * inventory */
             for (obj = mtmp->minvent; obj; obj = obj->nobj)
                 if ((temp = o_in(obj, oclass)) != 0) {
                     temp->ox = mtmp->mx;
                     temp->oy = mtmp->my;
                     map_object(temp, 1);
                     break; /* skip rest of this monster's inventory */
                 }
         newsym(u.ux, u.uy);
         u.uinwater = iflags.save_uinwater, u.uburied = iflags.save_uburied;
         if (sobj) {
             if (sobj->blessed) {
                 Your("%s %s to tingle and you smell %s.", body_part(NOSE),
                      u.uedibility ? "continues" : "starts", what);
                 u.uedibility = 1;
             } else
                 Your("%s tingles and you smell %s.", body_part(NOSE), what);
         } else
             You("sense %s.", what);
         display_nhwindow(WIN_MAP, TRUE);
         exercise(A_WIS, TRUE);
         docrt();
         if (Underwater)
             under_water(2);
         if (u.uburied)
             under_ground(2);
     }
     return 0;
 }
 

object_detect

 /*
  * Used for scrolls, potions, spells, and crystal balls.  Returns:
  *
  *      1 - nothing was detected
  *      0 - something was detected
  */
 int
 object_detect(detector, class)
 struct obj *detector; /* object doing the detecting */
 int class;            /* an object class, 0 for all */
 {
     register int x, y;
     char stuff[BUFSZ];
     int is_cursed = (detector && detector->cursed);
     int do_dknown = (detector && (detector->oclass == POTION_CLASS
                                   || detector->oclass == SPBOOK_CLASS)
                      && detector->blessed);
     int ct = 0, ctu = 0;
     register struct obj *obj, *otmp = (struct obj *) 0;
     register struct monst *mtmp;
     int sym, boulder = 0;
 
     if (class < 0 || class >= MAXOCLASSES) {
         impossible("object_detect:  illegal class %d", class);
         class = 0;
     }
 
     /* Special boulder symbol check - does the class symbol happen
      * to match iflags.bouldersym which is a user-defined?
      * If so, that means we aren't sure what they really wanted to
      * detect. Rather than trump anything, show both possibilities.
      * We can exclude checking the buried obj chain for boulders below.
      */
     sym = class ? def_oc_syms[class].sym : 0;
     if (sym && iflags.bouldersym && sym == iflags.bouldersym)
         boulder = ROCK_CLASS;
 
     if (Hallucination || (Confusion && class == SCROLL_CLASS))
         Strcpy(stuff, something);
     else
         Strcpy(stuff, class ? def_oc_syms[class].name : "objects");
     if (boulder && class != ROCK_CLASS)
         Strcat(stuff, " and/or large stones");
 
     if (do_dknown)
         for (obj = invent; obj; obj = obj->nobj)
             do_dknown_of(obj);
 
     for (obj = fobj; obj; obj = obj->nobj) {
         if ((!class && !boulder) || o_in(obj, class) || o_in(obj, boulder)) {
             if (obj->ox == u.ux && obj->oy == u.uy)
                 ctu++;
             else
                 ct++;
         }
         if (do_dknown)
             do_dknown_of(obj);
     }
 
     for (obj = level.buriedobjlist; obj; obj = obj->nobj) {
         if (!class || o_in(obj, class)) {
             if (obj->ox == u.ux && obj->oy == u.uy)
                 ctu++;
             else
                 ct++;
         }
         if (do_dknown)
             do_dknown_of(obj);
     }
 
     for (mtmp = fmon; mtmp; mtmp = mtmp->nmon) {
         if (DEADMONSTER(mtmp))
             continue;
         for (obj = mtmp->minvent; obj; obj = obj->nobj) {
             if ((!class && !boulder) || o_in(obj, class)
                 || o_in(obj, boulder))
                 ct++;
             if (do_dknown)
                 do_dknown_of(obj);
         }
         if ((is_cursed && mtmp->m_ap_type == M_AP_OBJECT
              && (!class || class == objects[mtmp->mappearance].oc_class))
             || (findgold(mtmp->minvent) && (!class || class == COIN_CLASS))) {
             ct++;
             break;
         }
     }
 
     if (!clear_stale_map(!class ? ALL_CLASSES : class, 0) && !ct) {
         if (!ctu) {
             if (detector)
                 strange_feeling(detector, "You feel a lack of something.");
             return 1;
         }
 
         You("sense %s nearby.", stuff);
         return 0;
     }
 
     cls();
 
     iflags.save_uinwater = u.uinwater, iflags.save_uburied = u.uburied;
     u.uinwater = u.uburied = 0;
     /*
      *  Map all buried objects first.
      */
     for (obj = level.buriedobjlist; obj; obj = obj->nobj)
         if (!class || (otmp = o_in(obj, class))) {
             if (class) {
                 if (otmp != obj) {
                     otmp->ox = obj->ox;
                     otmp->oy = obj->oy;
                 }
                 map_object(otmp, 1);
             } else
                 map_object(obj, 1);
         }
     /*
      * If we are mapping all objects, map only the top object of a pile or
      * the first object in a monster's inventory.  Otherwise, go looking
      * for a matching object class and display the first one encountered
      * at each location.
      *
      * Objects on the floor override buried objects.
      */
     for (x = 1; x < COLNO; x++)
         for (y = 0; y < ROWNO; y++)
             for (obj = level.objects[x][y]; obj; obj = obj->nexthere)
                 if ((!class && !boulder) || (otmp = o_in(obj, class))
                     || (otmp = o_in(obj, boulder))) {
                     if (class || boulder) {
                         if (otmp != obj) {
                             otmp->ox = obj->ox;
                             otmp->oy = obj->oy;
                         }
                         map_object(otmp, 1);
                     } else
                         map_object(obj, 1);
                     break;
                 }
 
     /* Objects in the monster's inventory override floor objects. */
     for (mtmp = fmon; mtmp; mtmp = mtmp->nmon) {
         if (DEADMONSTER(mtmp))
             continue;
         for (obj = mtmp->minvent; obj; obj = obj->nobj)
             if ((!class && !boulder) || (otmp = o_in(obj, class))
                 || (otmp = o_in(obj, boulder))) {
                 if (!class && !boulder)
                     otmp = obj;
                 otmp->ox = mtmp->mx; /* at monster location */
                 otmp->oy = mtmp->my;
                 map_object(otmp, 1);
                 break;
             }
         /* Allow a mimic to override the detected objects it is carrying. */
         if (is_cursed && mtmp->m_ap_type == M_AP_OBJECT
             && (!class || class == objects[mtmp->mappearance].oc_class)) {
             struct obj temp;
 
             temp.oextra = (struct oextra *) 0;
             temp.otyp = mtmp->mappearance; /* needed for obj_to_glyph() */
             temp.ox = mtmp->mx;
             temp.oy = mtmp->my;
             temp.corpsenm = PM_TENGU; /* if mimicing a corpse */
             map_object(&temp, 1);
         } else if (findgold(mtmp->minvent)
                    && (!class || class == COIN_CLASS)) {
             struct obj gold;
             gold = zeroobj; /* ensure oextra is cleared too */
             gold.otyp = GOLD_PIECE;
             gold.ox = mtmp->mx;
             gold.oy = mtmp->my;
             map_object(&gold, 1);
         }
     }
 
     newsym(u.ux, u.uy);
     u.uinwater = iflags.save_uinwater, u.uburied = iflags.save_uburied;
     You("detect the %s of %s.", ct ? "presence" : "absence", stuff);
     display_nhwindow(WIN_MAP, TRUE);
     /*
      * What are we going to do when the hero does an object detect while blind
      * and the detected object covers a known pool?
      */
     docrt(); /* this will correctly reset vision */
 
     if (Underwater)
         under_water(2);
     if (u.uburied)
         under_ground(2);
     return 0;
 }
 

monster_detect

 /*
  * Used by: crystal balls, potions, fountains
  *
  * Returns 1 if nothing was detected.
  * Returns 0 if something was detected.
  */
 int
 monster_detect(otmp, mclass)
 register struct obj *otmp; /* detecting object (if any) */
 int mclass;                /* monster class, 0 for all */
 {
     register struct monst *mtmp;
     int mcnt = 0;
 
     /* Note: This used to just check fmon for a non-zero value
      * but in versions since 3.3.0 fmon can test TRUE due to the
      * presence of dmons, so we have to find at least one
      * with positive hit-points to know for sure.
      */
     for (mtmp = fmon; mtmp; mtmp = mtmp->nmon)
         if (!DEADMONSTER(mtmp)) {
             mcnt++;
             break;
         }
 
     if (!mcnt) {
         if (otmp)
             strange_feeling(otmp, Hallucination
                                       ? "You get the heebie jeebies."
                                       : "You feel threatened.");
         return 1;
     } else {
         boolean woken = FALSE;
 
         cls();
         for (mtmp = fmon; mtmp; mtmp = mtmp->nmon) {
             if (DEADMONSTER(mtmp))
                 continue;
             if (!mclass || mtmp->data->mlet == mclass
                 || (mtmp->data == &mons[PM_LONG_WORM]
                     && mclass == S_WORM_TAIL))
                 if (mtmp->mx > 0) {
                     if (mclass && def_monsyms[mclass].sym == ' ')
                         show_glyph(mtmp->mx, mtmp->my,
                                    detected_mon_to_glyph(mtmp));
                     else
                         show_glyph(mtmp->mx, mtmp->my,
                                    mtmp->mtame ? pet_to_glyph(mtmp) : mon_to_glyph(mtmp));
                     /* don't be stingy - display entire worm */
                     if (mtmp->data == &mons[PM_LONG_WORM])
                         detect_wsegs(mtmp, 0);
                 }
             if (otmp && otmp->cursed
                 && (mtmp->msleeping || !mtmp->mcanmove)) {
                 mtmp->msleeping = mtmp->mfrozen = 0;
                 mtmp->mcanmove = 1;
                 woken = TRUE;
             }
         }
         display_self();
         You("sense the presence of monsters.");
         if (woken)
             pline("Monsters sense the presence of you.");
         display_nhwindow(WIN_MAP, TRUE);
         docrt();
         if (Underwater)
             under_water(2);
         if (u.uburied)
             under_ground(2);
     }
     return 0;
 }
 

sense_trap

 STATIC_OVL void
 sense_trap(trap, x, y, src_cursed)
 struct trap *trap;
 xchar x, y;
 int src_cursed;
 {
     if (Hallucination || src_cursed) {
         struct obj obj; /* fake object */
 
         obj.oextra = (struct oextra *) 0;
         if (trap) {
             obj.ox = trap->tx;
             obj.oy = trap->ty;
         } else {
             obj.ox = x;
             obj.oy = y;
         }
         obj.otyp = (src_cursed) ? GOLD_PIECE : random_object();
         obj.corpsenm = random_monster(); /* if otyp == CORPSE */
         map_object(&obj, 1);
     } else if (trap) {
         map_trap(trap, 1);
         trap->tseen = 1;
     } else {
         struct trap temp_trap; /* fake trap */
         temp_trap.tx = x;
         temp_trap.ty = y;
         temp_trap.ttyp = BEAR_TRAP; /* some kind of trap */
         map_trap(&temp_trap, 1);
     }
 }
 

detect_obj_traps

 #define OTRAP_NONE 0  /* nothing found */
 #define OTRAP_HERE 1  /* found at hero's location */
 #define OTRAP_THERE 2 /* found at any other location */
 
 /* check a list of objects for chest traps; return 1 if found at <ux,uy>,
    2 if found at some other spot, 3 if both, 0 otherwise; optionally
    update the map to show where such traps were found */
 STATIC_OVL int
 detect_obj_traps(objlist, show_them, how)
 struct obj *objlist;
 boolean show_them;
 int how; /* 1 for misleading map feedback */
 {
     struct obj *otmp;
     xchar x, y;
     int result = OTRAP_NONE;
 
     for (otmp = objlist; otmp; otmp = otmp->nobj) {
         if (Is_box(otmp) && otmp->otrapped
             && get_obj_location(otmp, &x, &y, BURIED_TOO | CONTAINED_TOO)) {
             result |= (x == u.ux && y == u.uy) ? OTRAP_HERE : OTRAP_THERE;
             if (show_them)
                 sense_trap((struct trap *) 0, x, y, how);
         }
         if (Has_contents(otmp))
             result |= detect_obj_traps(otmp->cobj, show_them, how);
     }
     return result;
 }
 

trap_detect

 /* the detections are pulled out so they can
  * also be used in the crystal ball routine
  * returns 1 if nothing was detected
  * returns 0 if something was detected
  */
 int
 trap_detect(sobj)
 register struct obj *sobj;
 /* sobj is null if crystal ball, *scroll if gold detection scroll */
 {
     register struct trap *ttmp;
     struct monst *mon;
     int door, glyph, tr;
     int cursed_src = sobj && sobj->cursed;
     boolean found = FALSE;
     coord cc;
 
     /* floor/ceiling traps */
     for (ttmp = ftrap; ttmp; ttmp = ttmp->ntrap) {
         if (ttmp->tx != u.ux || ttmp->ty != u.uy)
             goto outtrapmap;
         else
             found = TRUE;
     }
     /* chest traps (might be buried or carried) */
     if ((tr = detect_obj_traps(fobj, FALSE, 0)) != OTRAP_NONE) {
         if (tr & OTRAP_THERE)
             goto outtrapmap;
         else
             found = TRUE;
     }
     if ((tr = detect_obj_traps(level.buriedobjlist, FALSE, 0))
         != OTRAP_NONE) {
         if (tr & OTRAP_THERE)
             goto outtrapmap;
         else
             found = TRUE;
     }
     for (mon = fmon; mon; mon = mon->nmon) {
         if (DEADMONSTER(mon))
             continue;
         if ((tr = detect_obj_traps(mon->minvent, FALSE, 0)) != OTRAP_NONE) {
             if (tr & OTRAP_THERE)
                 goto outtrapmap;
             else
                 found = TRUE;
         }
     }
     if (detect_obj_traps(invent, FALSE, 0) != OTRAP_NONE)
         found = TRUE;
     /* door traps */
     for (door = 0; door < doorindex; door++) {
         cc = doors[door];
         if (levl[cc.x][cc.y].doormask & D_TRAPPED) {
             if (cc.x != u.ux || cc.y != u.uy)
                 goto outtrapmap;
             else
                 found = TRUE;
         }
     }
     if (!found) {
         char buf[BUFSZ];
 
         Sprintf(buf, "Your %s stop itching.", makeplural(body_part(TOE)));
         strange_feeling(sobj, buf);
         return 1;
     }
     /* traps exist, but only under me - no separate display required */
     Your("%s itch.", makeplural(body_part(TOE)));
     return 0;
 outtrapmap:
     cls();
 
     iflags.save_uinwater = u.uinwater, iflags.save_uburied = u.uburied;
     u.uinwater = u.uburied = 0;
 
     /* show chest traps first, so that subsequent floor trap display
        will override if both types are present at the same location */
     (void) detect_obj_traps(fobj, TRUE, cursed_src);
     (void) detect_obj_traps(level.buriedobjlist, TRUE, cursed_src);
     for (mon = fmon; mon; mon = mon->nmon) {
         if (DEADMONSTER(mon))
             continue;
         (void) detect_obj_traps(mon->minvent, TRUE, cursed_src);
     }
     (void) detect_obj_traps(invent, TRUE, cursed_src);
 
     for (ttmp = ftrap; ttmp; ttmp = ttmp->ntrap)
         sense_trap(ttmp, 0, 0, cursed_src);
 
     for (door = 0; door < doorindex; door++) {
         cc = doors[door];
         if (levl[cc.x][cc.y].doormask & D_TRAPPED)
             sense_trap((struct trap *) 0, cc.x, cc.y, cursed_src);
     }
 
     /* redisplay hero unless sense_trap() revealed something at <ux,uy> */
     glyph = glyph_at(u.ux, u.uy);
     if (!(glyph_is_trap(glyph) || glyph_is_object(glyph)))
         newsym(u.ux, u.uy);
     u.uinwater = iflags.save_uinwater, u.uburied = iflags.save_uburied;
 
     You_feel("%s.", cursed_src ? "very greedy" : "entrapped");
     /* wait for user to respond, then reset map display to normal */
     display_nhwindow(WIN_MAP, TRUE);
     docrt();
     if (Underwater)
         under_water(2);
     if (u.uburied)
         under_ground(2);
     return 0;
 }
 

level_distance

 const char *
 level_distance(where)
 d_level *where;
 {
     register schar ll = depth(&u.uz) - depth(where);
     register boolean indun = (u.uz.dnum == where->dnum);
 
     if (ll < 0) {
         if (ll < (-8 - rn2(3)))
             if (!indun)
                 return "far away";
             else
                 return "far below";
         else if (ll < -1)
             if (!indun)
                 return "away below you";
             else
                 return "below you";
         else if (!indun)
             return "in the distance";
         else
             return "just below";
     } else if (ll > 0) {
         if (ll > (8 + rn2(3)))
             if (!indun)
                 return "far away";
             else
                 return "far above";
         else if (ll > 1)
             if (!indun)
                 return "away above you";
             else
                 return "above you";
         else if (!indun)
             return "in the distance";
         else
             return "just above";
     } else if (!indun)
         return "in the distance";
     else
         return "near you";
 }
 

use_crystal_ball

 static const struct {
     const char *what;
     d_level *where;
 } level_detects[] = {
     { "Delphi", &oracle_level },
     { "Medusa's lair", &medusa_level },
     { "a castle", &stronghold_level },
     { "the Wizard of Yendor's tower", &wiz1_level },
 };
 
 void
 use_crystal_ball(optr)
 struct obj **optr;
 {
     char ch;
     int oops;
     struct obj *obj = *optr;
 
     if (Blind) {
         pline("Too bad you can't see %s.", the(xname(obj)));
         return;
     }
     oops = (rnd(20) > ACURR(A_INT) || obj->cursed);
     if (oops && (obj->spe > 0)) {
         switch (rnd(obj->oartifact ? 4 : 5)) {
         case 1:
             pline("%s too much to comprehend!", Tobjnam(obj, "are"));
             break;
         case 2:
             pline("%s you!", Tobjnam(obj, "confuse"));
             make_confused((HConfusion & TIMEOUT) + (long) rnd(100), FALSE);
             break;
         case 3:
             if (!resists_blnd(&youmonst)) {
                 pline("%s your vision!", Tobjnam(obj, "damage"));
                 make_blinded((Blinded & TIMEOUT) + (long) rnd(100), FALSE);
                 if (!Blind)
                     Your1(vision_clears);
             } else {
                 pline("%s your vision.", Tobjnam(obj, "assault"));
                 You("are unaffected!");
             }
             break;
         case 4:
             pline("%s your mind!", Tobjnam(obj, "zap"));
             (void) make_hallucinated(
                 (HHallucination & TIMEOUT) + (long) rnd(100), FALSE, 0L);
             break;
         case 5:
             pline("%s!", Tobjnam(obj, "explode"));
             useup(obj);
             *optr = obj = 0; /* it's gone */
             /* physical damage cause by the shards and force */
             losehp(Maybe_Half_Phys(rnd(30)), "exploding crystal ball",
                    KILLED_BY_AN);
             break;
         }
         if (obj)
             consume_obj_charge(obj, TRUE);
         return;
     }
 
     if (Hallucination) {
         if (!obj->spe) {
             pline("All you see is funky %s haze.", hcolor((char *) 0));
         } else {
             switch (rnd(6)) {
             case 1:
                 You("grok some groovy globs of incandescent lava.");
                 break;
             case 2:
                 pline("Whoa!  Psychedelic colors, %s!",
                       poly_gender() == 1 ? "babe" : "dude");
                 break;
             case 3:
                 pline_The("crystal pulses with sinister %s light!",
                           hcolor((char *) 0));
                 break;
             case 4:
                 You_see("goldfish swimming above fluorescent rocks.");
                 break;
             case 5:
                 You_see(
                     "tiny snowflakes spinning around a miniature farmhouse.");
                 break;
             default:
                 pline("Oh wow... like a kaleidoscope!");
                 break;
             }
             consume_obj_charge(obj, TRUE);
         }
         return;
     }
 
     /* read a single character */
     if (flags.verbose)
         You("may look for an object or monster symbol.");
     ch = yn_function("What do you look for?", (char *) 0, '\0');
     /* Don't filter out ' ' here; it has a use */
     if ((ch != def_monsyms[S_GHOST].sym) && index(quitchars, ch)) {
         if (flags.verbose)
             pline1(Never_mind);
         return;
     }
     You("peer into %s...", the(xname(obj)));
     nomul(-rnd(10));
     multi_reason = "gazing into a crystal ball";
     nomovemsg = "";
     if (obj->spe <= 0)
         pline_The("vision is unclear.");
     else {
         int class;
         int ret = 0;
 
         makeknown(CRYSTAL_BALL);
         consume_obj_charge(obj, TRUE);
 
         /* special case: accept ']' as synonym for mimic
          * we have to do this before the def_char_to_objclass check
          */
         if (ch == DEF_MIMIC_DEF)
             ch = DEF_MIMIC;
 
         if ((class = def_char_to_objclass(ch)) != MAXOCLASSES)
             ret = object_detect((struct obj *) 0, class);
         else if ((class = def_char_to_monclass(ch)) != MAXMCLASSES)
             ret = monster_detect((struct obj *) 0, class);
         else if (iflags.bouldersym && (ch == iflags.bouldersym))
             ret = object_detect((struct obj *) 0, ROCK_CLASS);
         else
             switch (ch) {
             case '^':
                 ret = trap_detect((struct obj *) 0);
                 break;
             default: {
                 int i = rn2(SIZE(level_detects));
                 You_see("%s, %s.", level_detects[i].what,
                         level_distance(level_detects[i].where));
             }
                 ret = 0;
                 break;
             }
 
         if (ret) {
             if (!rn2(100)) /* make them nervous */
                 You_see("the Wizard of Yendor gazing out at you.");
             else
                 pline_The("vision is unclear.");
         }
     }
     return;
 }
 

show_map_spot

 STATIC_OVL void
 show_map_spot(x, y)
 register int x, y;
 {
     struct rm *lev;
     struct trap *t;
     int oldglyph;
 
     if (Confusion && rn2(7))
         return;
     lev = &levl[x][y];
 
     lev->seenv = SVALL;
 
     /* Secret corridors are found, but not secret doors. */
     if (lev->typ == SCORR) {
         lev->typ = CORR;
         unblock_point(x, y);
     }
 
     /*
      * Force the real background, then if it's not furniture and there's
      * a known trap there, display the trap, else if there was an object
      * shown there, redisplay the object.  So during mapping, furniture
      * takes precedence over traps, which take precedence over objects,
      * opposite to how normal vision behaves.
      */
     oldglyph = glyph_at(x, y);
     if (level.flags.hero_memory) {
         magic_map_background(x, y, 0);
         newsym(x, y); /* show it, if not blocked */
     } else {
         magic_map_background(x, y, 1); /* display it */
     }
     if (!IS_FURNITURE(lev->typ)) {
         if ((t = t_at(x, y)) != 0 && t->tseen) {
             map_trap(t, 1);
         } else if (glyph_is_trap(oldglyph) || glyph_is_object(oldglyph)) {
             show_glyph(x, y, oldglyph);
             if (level.flags.hero_memory)
                 lev->glyph = oldglyph;
         }
     }
 }
 

do_mapping

 void
 do_mapping()
 {
     register int zx, zy;
 
     iflags.save_uinwater = u.uinwater, iflags.save_uburied = u.uburied;
     u.uinwater = u.uburied = 0;
     for (zx = 1; zx < COLNO; zx++)
         for (zy = 0; zy < ROWNO; zy++)
             show_map_spot(zx, zy);
     u.uinwater = iflags.save_uinwater, u.uburied = iflags.save_uburied;
     if (!level.flags.hero_memory || Underwater) {
         flush_screen(1);                 /* flush temp screen */
         display_nhwindow(WIN_MAP, TRUE); /* wait */
         docrt();
     }
     exercise(A_WIS, TRUE);
 }
 

do_vicinity_map

 void
 do_vicinity_map()
 {
     register int zx, zy;
     int lo_y = (u.uy - 5 < 0 ? 0 : u.uy - 5),
         hi_y = (u.uy + 6 > ROWNO ? ROWNO : u.uy + 6),
         lo_x = (u.ux - 9 < 1 ? 1 : u.ux - 9), /* avoid column 0 */
         hi_x = (u.ux + 10 > COLNO ? COLNO : u.ux + 10);
 
     for (zx = lo_x; zx < hi_x; zx++)
         for (zy = lo_y; zy < hi_y; zy++)
             show_map_spot(zx, zy);
 
     if (!level.flags.hero_memory || Underwater) {
         flush_screen(1);                 /* flush temp screen */
         display_nhwindow(WIN_MAP, TRUE); /* wait */
         docrt();
     }
 }
 

cvt_sdoor_to_door

 /* convert a secret door into a normal door */
 void
 cvt_sdoor_to_door(lev)
 struct rm *lev;
 {
     int newmask = lev->doormask & ~WM_MASK;
 
     if (Is_rogue_level(&u.uz))
         /* rogue didn't have doors, only doorways */
         newmask = D_NODOOR;
     else
         /* newly exposed door is closed */
         if (!(newmask & D_LOCKED))
         newmask |= D_CLOSED;
 
     lev->typ = DOOR;
     lev->doormask = newmask;
 }
 

findone

 STATIC_PTR void
 findone(zx, zy, num)
 int zx, zy;
 genericptr_t num;
 {
     register struct trap *ttmp;
     register struct monst *mtmp;
 
     if (levl[zx][zy].typ == SDOOR) {
         cvt_sdoor_to_door(&levl[zx][zy]); /* .typ = DOOR */
         magic_map_background(zx, zy, 0);
         newsym(zx, zy);
         (*(int *) num)++;
     } else if (levl[zx][zy].typ == SCORR) {
         levl[zx][zy].typ = CORR;
         unblock_point(zx, zy);
         magic_map_background(zx, zy, 0);
         newsym(zx, zy);
         (*(int *) num)++;
     } else if ((ttmp = t_at(zx, zy)) != 0) {
         if (!ttmp->tseen && ttmp->ttyp != STATUE_TRAP) {
             ttmp->tseen = 1;
             newsym(zx, zy);
             (*(int *) num)++;
         }
     } else if ((mtmp = m_at(zx, zy)) != 0) {
         if (mtmp->m_ap_type) {
             seemimic(mtmp);
             (*(int *) num)++;
         }
         if (mtmp->mundetected
             && (is_hider(mtmp->data) || mtmp->data->mlet == S_EEL)) {
             mtmp->mundetected = 0;
             newsym(zx, zy);
             (*(int *) num)++;
         }
         if (!canspotmon(mtmp) && !glyph_is_invisible(levl[zx][zy].glyph))
             map_invisible(zx, zy);
     } else if (glyph_is_invisible(levl[zx][zy].glyph)) {
         unmap_object(zx, zy);
         newsym(zx, zy);
         (*(int *) num)++;
     }
 }
 

openone

 STATIC_PTR void
 openone(zx, zy, num)
 int zx, zy;
 genericptr_t num;
 {
     register struct trap *ttmp;
     register struct obj *otmp;
     int *num_p = (int *) num;
 
     if (OBJ_AT(zx, zy)) {
         for (otmp = level.objects[zx][zy]; otmp; otmp = otmp->nexthere) {
             if (Is_box(otmp) && otmp->olocked) {
                 otmp->olocked = 0;
                 (*num_p)++;
             }
         }
         /* let it fall to the next cases. could be on trap. */
     }
     if (levl[zx][zy].typ == SDOOR
         || (levl[zx][zy].typ == DOOR
             && (levl[zx][zy].doormask & (D_CLOSED | D_LOCKED)))) {
         if (levl[zx][zy].typ == SDOOR)
             cvt_sdoor_to_door(&levl[zx][zy]); /* .typ = DOOR */
         if (levl[zx][zy].doormask & D_TRAPPED) {
             if (distu(zx, zy) < 3)
                 b_trapped("door", 0);
             else
                 Norep("You %s an explosion!",
                       cansee(zx, zy) ? "see" : (!Deaf ? "hear"
                                                       : "feel the shock of"));
             wake_nearto(zx, zy, 11 * 11);
             levl[zx][zy].doormask = D_NODOOR;
         } else
             levl[zx][zy].doormask = D_ISOPEN;
         unblock_point(zx, zy);
         newsym(zx, zy);
         (*num_p)++;
     } else if (levl[zx][zy].typ == SCORR) {
         levl[zx][zy].typ = CORR;
         unblock_point(zx, zy);
         newsym(zx, zy);
         (*num_p)++;
     } else if ((ttmp = t_at(zx, zy)) != 0) {
         struct monst *mon;
         boolean dummy; /* unneeded "you notice it arg" */
 
         if (!ttmp->tseen && ttmp->ttyp != STATUE_TRAP) {
             ttmp->tseen = 1;
             newsym(zx, zy);
             (*num_p)++;
         }
         mon = (zx == u.ux && zy == u.uy) ? &youmonst : m_at(zx, zy);
         if (openholdingtrap(mon, &dummy)
             || openfallingtrap(mon, TRUE, &dummy))
             (*num_p)++;
     } else if (find_drawbridge(&zx, &zy)) {
         /* make sure it isn't an open drawbridge */
         open_drawbridge(zx, zy);
         (*num_p)++;
     }
 }
 

findit

 /* returns number of things found */
 int
 findit()
 {
     int num = 0;
 
     if (u.uswallow)
         return 0;
     do_clear_area(u.ux, u.uy, BOLT_LIM, findone, (genericptr_t) &num);
     return num;
 }
 

openit

 /* returns number of things found and opened */
 int
 openit()
 {
     int num = 0;
 
     if (u.uswallow) {
         if (is_animal(u.ustuck->data)) {
             if (Blind)
                 pline("Its mouth opens!");
             else
                 pline("%s opens its mouth!", Monnam(u.ustuck));
         }
         expels(u.ustuck, u.ustuck->data, TRUE);
         return -1;
     }
 
     do_clear_area(u.ux, u.uy, BOLT_LIM, openone, (genericptr_t) &num);
     return num;
 }
 

detecting

 /* callback hack for overriding vision in do_clear_area() */
 boolean
 detecting(func)
 void FDECL((*func), (int, int, genericptr_t));
 {
     return (func == findone || func == openone);
 }
 

find_trap

 void
 find_trap(trap)
 struct trap *trap;
 {
     int tt = what_trap(trap->ttyp);
     boolean cleared = FALSE;
 
     trap->tseen = 1;
     exercise(A_WIS, TRUE);
     feel_newsym(trap->tx, trap->ty);
 
     if (levl[trap->tx][trap->ty].glyph != trap_to_glyph(trap)) {
         /* There's too much clutter to see your find otherwise */
         cls();
         map_trap(trap, 1);
         display_self();
         cleared = TRUE;
     }
 
     You("find %s.", an(defsyms[trap_to_defsym(tt)].explanation));
 
     if (cleared) {
         display_nhwindow(WIN_MAP, TRUE); /* wait */
         docrt();
     }
 }
 

dosearch0

 int
 dosearch0(aflag)
 register int aflag; /* intrinsic autosearch vs explicit searching */
 {
 #ifdef GCC_BUG
     /* some versions of gcc seriously muck up nested loops. if you get strange
        crashes while searching in a version compiled with gcc, try putting
        #define GCC_BUG in *conf.h (or adding -DGCC_BUG to CFLAGS in the
        makefile).
      */
     volatile xchar x, y;
 #else
     register xchar x, y;
 #endif
     register struct trap *trap;
     register struct monst *mtmp;
 
     if (u.uswallow) {
         if (!aflag)
             pline("What are you looking for?  The exit?");
     } else {
         int fund = (uwep && uwep->oartifact
                     && spec_ability(uwep, SPFX_SEARCH)) ? uwep->spe : 0;
 
         if (ublindf && ublindf->otyp == LENSES && !Blind)
             fund += 2; /* JDS: lenses help searching */
         if (fund > 5)
             fund = 5;
         for (x = u.ux - 1; x < u.ux + 2; x++)
             for (y = u.uy - 1; y < u.uy + 2; y++) {
                 if (!isok(x, y))
                     continue;
                 if (x == u.ux && y == u.uy)
                     continue;
 
                 if (Blind && !aflag)
                     feel_location(x, y);
                 if (levl[x][y].typ == SDOOR) {
                     if (rnl(7 - fund))
                         continue;
                     cvt_sdoor_to_door(&levl[x][y]); /* .typ = DOOR */
                     exercise(A_WIS, TRUE);
                     nomul(0);
                     feel_location(x, y); /* make sure it shows up */
                     You("find a hidden door.");
                 } else if (levl[x][y].typ == SCORR) {
                     if (rnl(7 - fund))
                         continue;
                     levl[x][y].typ = CORR;
                     unblock_point(x, y); /* vision */
                     exercise(A_WIS, TRUE);
                     nomul(0);
                     feel_location(x, y); /* make sure it shows up */
                     You("find a hidden passage.");
                 } else {
                     /* Be careful not to find anything in an SCORR or SDOOR */
                     if ((mtmp = m_at(x, y)) != 0 && !aflag) {
                         if (mtmp->m_ap_type) {
                             seemimic(mtmp);
                         find:
                             exercise(A_WIS, TRUE);
                             if (!canspotmon(mtmp)) {
                                 if (glyph_is_invisible(levl[x][y].glyph)) {
                                     /* found invisible monster in a square
                                      * which already has an 'I' in it.
                                      * Logically, this should still take
                                      * time and lead to a return(1), but
                                      * if we did that the player would keep
                                      * finding the same monster every turn.
                                      */
                                     continue;
                                 } else {
                                     You_feel("an unseen monster!");
                                     map_invisible(x, y);
                                 }
                             } else if (!sensemon(mtmp))
                                 You("find %s.", mtmp->mtame
                                                    ? y_monnam(mtmp)
                                                    : a_monnam(mtmp));
                             return 1;
                         }
                         if (!canspotmon(mtmp)) {
                             if (mtmp->mundetected
                                 && (is_hider(mtmp->data)
                                     || mtmp->data->mlet == S_EEL))
                                 mtmp->mundetected = 0;
                             newsym(x, y);
                             goto find;
                         }
                     }
 
                     /* see if an invisible monster has moved--if Blind,
                      * feel_location() already did it
                      */
                     if (!aflag && !mtmp && !Blind
                         && glyph_is_invisible(levl[x][y].glyph)) {
                         unmap_object(x, y);
                         newsym(x, y);
                     }
 
                     if ((trap = t_at(x, y)) && !trap->tseen && !rnl(8)) {
                         nomul(0);
                         if (trap->ttyp == STATUE_TRAP) {
                             if (activate_statue_trap(trap, x, y, FALSE))
                                 exercise(A_WIS, TRUE);
                             return 1;
                         } else {
                             find_trap(trap);
                         }
                     }
                 }
             }
     }
     return 1;
 }
 

dosearch

 /* the 's' command -- explicit searching */
 int
 dosearch()
 {
     return dosearch0(0);
 }
 

sokoban_detect

 /* Pre-map the sokoban levels */
 void
 sokoban_detect()
 {
     register int x, y;
     register struct trap *ttmp;
     register struct obj *obj;
 
     /* Map the background and boulders */
     for (x = 1; x < COLNO; x++)
         for (y = 0; y < ROWNO; y++) {
             levl[x][y].seenv = SVALL;
             levl[x][y].waslit = TRUE;
             map_background(x, y, 1);
             if ((obj = sobj_at(BOULDER, x, y)) != 0)
                 map_object(obj, 1);
         }
 
     /* Map the traps */
     for (ttmp = ftrap; ttmp; ttmp = ttmp->ntrap) {
         ttmp->tseen = 1;
         map_trap(ttmp, 1);
         /* set sokoban_rules when there is at least one pit or hole */
         if (ttmp->ttyp == PIT || ttmp->ttyp == HOLE)
             Sokoban = 1;
     }
 }
 

reveal_terrain

 /* idea from crawl; show known portion of map without any monsters,
    objects, or traps occluding the view of the underlying terrain */
 void
 reveal_terrain(full, which_subset)
 int full; /* wizard|explore modes allow player to request full map */
 int which_subset; /* when not full, whether to suppress objs and/or traps */
 {
     if ((Hallucination || Stunned || Confusion) && !full) {
         You("are too disoriented for this.");
     } else {
         int x, y, glyph, levl_glyph, default_glyph;
         uchar seenv;
         unsigned save_swallowed;
         struct monst *mtmp;
         struct trap *t;
         char buf[BUFSZ];
         boolean keep_traps = (which_subset & 1) !=0,
                 keep_objs = (which_subset & 2) != 0,
                 keep_mons = (which_subset & 4) != 0; /* actually always 0 */
 
         save_swallowed = u.uswallow;
         iflags.save_uinwater = u.uinwater, iflags.save_uburied = u.uburied;
         u.uinwater = u.uburied = 0;
         u.uswallow = 0;
         default_glyph = cmap_to_glyph(level.flags.arboreal ? S_tree : S_stone);
         /* for 'full', show the actual terrain for the entire level,
            otherwise what the hero remembers for seen locations with
            monsters, objects, and/or traps removed as caller dictates */
         for (x = 1; x < COLNO; x++)
             for (y = 0; y < ROWNO; y++) {
                 seenv = (full || level.flags.hero_memory)
                            ? levl[x][y].seenv : cansee(x, y) ? SVALL : 0;
                 if (full) {
                     levl[x][y].seenv = SVALL;
                     glyph = back_to_glyph(x, y);
                     levl[x][y].seenv = seenv;
                 } else {
                     levl_glyph = level.flags.hero_memory
                                     ? levl[x][y].glyph
                                     : seenv
                                        ? back_to_glyph(x, y)
                                        : default_glyph;
                     /* glyph_at() returns the displayed glyph, which might
                        be a monster.  levl[][].glyph contains the remembered
                        glyph, which will never be a monster (unless it is
                        the invisible monster glyph, which is handled like
                        an object, replacing any object or trap at its spot) */
                     glyph = !save_swallowed ? glyph_at(x, y) : levl_glyph;
                     if (keep_mons && x == u.ux && y == u.uy && save_swallowed)
                         glyph = mon_to_glyph(u.ustuck);
                     else if (((glyph_is_monster(glyph)
                                || glyph_is_warning(glyph)) && !keep_mons)
                              || glyph_is_swallow(glyph))
                         glyph = levl_glyph;
                     if (((glyph_is_object(glyph) && !keep_objs)
                          || glyph_is_invisible(glyph))
                         && keep_traps && !covers_traps(x, y)) {
                         if ((t = t_at(x, y)) != 0 && t->tseen)
                             glyph = trap_to_glyph(t);
                     }
                     if ((glyph_is_object(glyph) && !keep_objs)
                         || (glyph_is_trap(glyph) && !keep_traps)
                         || glyph_is_invisible(glyph)) {
                         if (!seenv) {
                             glyph = default_glyph;
                         } else if (lastseentyp[x][y] == levl[x][y].typ) {
                             glyph = back_to_glyph(x, y);
                         } else {
                             /* look for a mimic here posing as furniture;
                                if we don't find one, we'll have to fake it */
                             if ((mtmp = m_at(x, y)) != 0
                                 && mtmp->m_ap_type == M_AP_FURNITURE) {
                                 glyph = cmap_to_glyph(mtmp->mappearance);
                             } else {
                                 /* we have a topology type but we want a
                                    screen symbol in order to derive a glyph;
                                    some screen symbols need the flags field
                                    of levl[][] in addition to the type
                                    (to disambiguate STAIRS to S_upstair or
                                    S_dnstair, for example; current flags
                                    might not be intended for remembered
                                    type, but we've got no other choice) */
                                 schar save_typ = levl[x][y].typ;
 
                                 levl[x][y].typ = lastseentyp[x][y];
                                 glyph = back_to_glyph(x, y);
                                 levl[x][y].typ = save_typ;
                             }
                         }
                     }
                 }
                 show_glyph(x, y, glyph);
             }
 
         /* [TODO: highlight hero's location somehow] */
         u.uinwater = iflags.save_uinwater, u.uburied = iflags.save_uburied;
         if (save_swallowed)
             u.uswallow = 1;
         flush_screen(1);
         if (full) {
             Strcpy(buf, "underlying terrain");
         } else {
             Strcpy(buf, "known terrain");
             if (keep_traps)
                 Sprintf(eos(buf), "%s traps",
                         (keep_objs || keep_mons) ? "," : " and");
             if (keep_objs)
                 Sprintf(eos(buf), "%s%s objects",
                         (keep_traps || keep_mons) ? "," : "",
                         keep_mons ? "" : " and");
             if (keep_mons)
                 Sprintf(eos(buf), "%s and monsters",
                         (keep_traps || keep_objs) ? "," : "");
         }
         pline("Showing %s only...", buf);
         display_nhwindow(WIN_MAP, TRUE); /* give "--More--" prompt */
         docrt(); /* redraw the screen, restoring regular map */
         if (Underwater)
             under_water(2);
         if (u.uburied)
             under_ground(2);
     }
     return;
 }
 
 /*detect.c*/