Source:NetHack 3.6.1/src/light.c

From NetHackWiki
Jump to navigation Jump to search

Below is the full text to light.c from the source code of NetHack 3.6.1. To link to a particular line, write [[Source:NetHack 3.6.1/src/light.c#line123]], for example.

Top of file

 /* NetHack 3.6	light.c	$NHDT-Date: 1446191876 2015/10/30 07:57:56 $  $NHDT-Branch: master $:$NHDT-Revision: 1.28 $ */
 /* Copyright (c) Dean Luick, 1994                                       */
 /* 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.

 
 #include "hack.h"
 #include "lev.h" /* for checking save modes */
 
 /*
  * Mobile light sources.
  *
  * This implementation minimizes memory at the expense of extra
  * recalculations.
  *
  * Light sources are "things" that have a physical position and range.
  * They have a type, which gives us information about them.  Currently
  * they are only attached to objects and monsters.  Note well:  the
  * polymorphed-player handling assumes that both youmonst.m_id and
  * youmonst.mx will always remain 0.
  *
  * Light sources, like timers, either follow game play (RANGE_GLOBAL) or
  * stay on a level (RANGE_LEVEL).  Light sources are unique by their
  * (type, id) pair.  For light sources attached to objects, this id
  * is a pointer to the object.
  *
  * The major working function is do_light_sources(). It is called
  * when the vision system is recreating its "could see" array.  Here
  * we add a flag (TEMP_LIT) to the array for all locations that are lit
  * via a light source.  The bad part of this is that we have to
  * re-calculate the LOS of each light source every time the vision
  * system runs.  Even if the light sources and any topology (vision blocking
  * positions) have not changed.  The good part is that no extra memory
  * is used, plus we don't have to figure out how far the sources have moved,
  * or if the topology has changed.
  *
  * The structure of the save/restore mechanism is amazingly similar to
  * the timer save/restore.  This is because they both have the same
  * principals of having pointers into objects that must be recalculated
  * across saves and restores.
  */
 
 /* flags */
 #define LSF_SHOW 0x1        /* display the light source */
 #define LSF_NEEDS_FIXUP 0x2 /* need oid fixup */
 
 static light_source *light_base = 0;
 
 STATIC_DCL void FDECL(write_ls, (int, light_source *));
 STATIC_DCL int FDECL(maybe_write_ls, (int, int, BOOLEAN_P));
 
 /* imported from vision.c, for small circles */
 extern char circle_data[];
 extern char circle_start[];
 

new_light_source

 /* Create a new light source.  */
 void
 new_light_source(x, y, range, type, id)
 xchar x, y;
 int range, type;
 anything *id;
 {
     light_source *ls;
 
     if (range > MAX_RADIUS || range < 1) {
         impossible("new_light_source:  illegal range %d", range);
         return;
     }
 
     ls = (light_source *) alloc(sizeof(light_source));
 
     ls->next = light_base;
     ls->x = x;
     ls->y = y;
     ls->range = range;
     ls->type = type;
     ls->id = *id;
     ls->flags = 0;
     light_base = ls;
 
     vision_full_recalc = 1; /* make the source show up */
 }
 

del_light_source

 /*
  * Delete a light source. This assumes only one light source is attached
  * to an object at a time.
  */
 void
 del_light_source(type, id)
 int type;
 anything *id;
 {
     light_source *curr, *prev;
     anything tmp_id;
 
     tmp_id = zeroany;
     /* need to be prepared for dealing a with light source which
        has only been partially restored during a level change
        (in particular: chameleon vs prot. from shape changers) */
     switch (type) {
     case LS_OBJECT:
         tmp_id.a_uint = id->a_obj->o_id;
         break;
     case LS_MONSTER:
         tmp_id.a_uint = id->a_monst->m_id;
         break;
     default:
         tmp_id.a_uint = 0;
         break;
     }
 
     for (prev = 0, curr = light_base; curr; prev = curr, curr = curr->next) {
         if (curr->type != type)
             continue;
         if (curr->id.a_obj
             == ((curr->flags & LSF_NEEDS_FIXUP) ? tmp_id.a_obj : id->a_obj)) {
             if (prev)
                 prev->next = curr->next;
             else
                 light_base = curr->next;
 
             free((genericptr_t) curr);
             vision_full_recalc = 1;
             return;
         }
     }
     impossible("del_light_source: not found type=%d, id=%s", type,
                fmt_ptr((genericptr_t) id->a_obj));
 }
 

do_light_sources

 /* Mark locations that are temporarily lit via mobile light sources. */
 void
 do_light_sources(cs_rows)
 char **cs_rows;
 {
     int x, y, min_x, max_x, max_y, offset;
     char *limits;
     short at_hero_range = 0;
     light_source *ls;
     char *row;
 
     for (ls = light_base; ls; ls = ls->next) {
         ls->flags &= ~LSF_SHOW;
 
         /*
          * Check for moved light sources.  It may be possible to
          * save some effort if an object has not moved, but not in
          * the current setup -- we need to recalculate for every
          * vision recalc.
          */
         if (ls->type == LS_OBJECT) {
             if (get_obj_location(ls->id.a_obj, &ls->x, &ls->y, 0))
                 ls->flags |= LSF_SHOW;
         } else if (ls->type == LS_MONSTER) {
             if (get_mon_location(ls->id.a_monst, &ls->x, &ls->y, 0))
                 ls->flags |= LSF_SHOW;
         }
 
         /* minor optimization: don't bother with duplicate light sources */
         /* at hero */
         if (ls->x == u.ux && ls->y == u.uy) {
             if (at_hero_range >= ls->range)
                 ls->flags &= ~LSF_SHOW;
             else
                 at_hero_range = ls->range;
         }
 
         if (ls->flags & LSF_SHOW) {
             /*
              * Walk the points in the circle and see if they are
              * visible from the center.  If so, mark'em.
              *
              * Kevin's tests indicated that doing this brute-force
              * method is faster for radius <= 3 (or so).
              */
             limits = circle_ptr(ls->range);
             if ((max_y = (ls->y + ls->range)) >= ROWNO)
                 max_y = ROWNO - 1;
             if ((y = (ls->y - ls->range)) < 0)
                 y = 0;
             for (; y <= max_y; y++) {
                 row = cs_rows[y];
                 offset = limits[abs(y - ls->y)];
                 if ((min_x = (ls->x - offset)) < 0)
                     min_x = 0;
                 if ((max_x = (ls->x + offset)) >= COLNO)
                     max_x = COLNO - 1;
 
                 if (ls->x == u.ux && ls->y == u.uy) {
                     /*
                      * If the light source is located at the hero, then
                      * we can use the COULD_SEE bits already calculated
                      * by the vision system.  More importantly than
                      * this optimization, is that it allows the vision
                      * system to correct problems with clear_path().
                      * The function clear_path() is a simple LOS
                      * path checker that doesn't go out of its way
                      * make things look "correct".  The vision system
                      * does this.
                      */
                     for (x = min_x; x <= max_x; x++)
                         if (row[x] & COULD_SEE)
                             row[x] |= TEMP_LIT;
                 } else {
                     for (x = min_x; x <= max_x; x++)
                         if ((ls->x == x && ls->y == y)
                             || clear_path((int) ls->x, (int) ls->y, x, y))
                             row[x] |= TEMP_LIT;
                 }
             }
         }
     }
 }
 
 /* (mon->mx == 0) implies migrating */
 #define mon_is_local(mon) ((mon)->mx > 0)
 

find_mid

 struct monst *
 find_mid(nid, fmflags)
 unsigned nid;
 unsigned fmflags;
 {
     struct monst *mtmp;
 
     if (!nid)
         return &youmonst;
     if (fmflags & FM_FMON)
         for (mtmp = fmon; mtmp; mtmp = mtmp->nmon)
             if (!DEADMONSTER(mtmp) && mtmp->m_id == nid)
                 return mtmp;
     if (fmflags & FM_MIGRATE)
         for (mtmp = migrating_mons; mtmp; mtmp = mtmp->nmon)
             if (mtmp->m_id == nid)
                 return mtmp;
     if (fmflags & FM_MYDOGS)
         for (mtmp = mydogs; mtmp; mtmp = mtmp->nmon)
             if (mtmp->m_id == nid)
                 return mtmp;
     return (struct monst *) 0;
 }
 

save_light_sources

 /* Save all light sources of the given range. */
 void
 save_light_sources(fd, mode, range)
 int fd, mode, range;
 {
     int count, actual, is_global;
     light_source **prev, *curr;
 
     if (perform_bwrite(mode)) {
         count = maybe_write_ls(fd, range, FALSE);
         bwrite(fd, (genericptr_t) &count, sizeof count);
         actual = maybe_write_ls(fd, range, TRUE);
         if (actual != count)
             panic("counted %d light sources, wrote %d! [range=%d]", count,
                   actual, range);
     }
 
     if (release_data(mode)) {
         for (prev = &light_base; (curr = *prev) != 0;) {
             if (!curr->id.a_monst) {
                 impossible("save_light_sources: no id! [range=%d]", range);
                 is_global = 0;
             } else
                 switch (curr->type) {
                 case LS_OBJECT:
                     is_global = !obj_is_local(curr->id.a_obj);
                     break;
                 case LS_MONSTER:
                     is_global = !mon_is_local(curr->id.a_monst);
                     break;
                 default:
                     is_global = 0;
                     impossible("save_light_sources: bad type (%d) [range=%d]",
                                curr->type, range);
                     break;
                 }
             /* if global and not doing local, or vice versa, remove it */
             if (is_global ^ (range == RANGE_LEVEL)) {
                 *prev = curr->next;
                 free((genericptr_t) curr);
             } else {
                 prev = &(*prev)->next;
             }
         }
     }
 }
 

restore_light_sources

 /*
  * Pull in the structures from disk, but don't recalculate the object
  * pointers.
  */
 void
 restore_light_sources(fd)
 int fd;
 {
     int count;
     light_source *ls;
 
     /* restore elements */
     mread(fd, (genericptr_t) &count, sizeof count);
 
     while (count-- > 0) {
         ls = (light_source *) alloc(sizeof(light_source));
         mread(fd, (genericptr_t) ls, sizeof(light_source));
         ls->next = light_base;
         light_base = ls;
     }
 }
 

light_stats

 /* to support '#stats' wizard-mode command */
 void
 light_stats(hdrfmt, hdrbuf, count, size)
 const char *hdrfmt;
 char *hdrbuf;
 long *count, *size;
 {
     light_source *ls;
 
     Sprintf(hdrbuf, hdrfmt, (long) sizeof (light_source));
     *count = *size = 0L;
     for (ls = light_base; ls; ls = ls->next) {
         ++*count;
         *size += (long) sizeof *ls;
     }
 }
 

relink_light_sources

 /* Relink all lights that are so marked. */
 void
 relink_light_sources(ghostly)
 boolean ghostly;
 {
     char which;
     unsigned nid;
     light_source *ls;
 
     for (ls = light_base; ls; ls = ls->next) {
         if (ls->flags & LSF_NEEDS_FIXUP) {
             if (ls->type == LS_OBJECT || ls->type == LS_MONSTER) {
                 if (ghostly) {
                     if (!lookup_id_mapping(ls->id.a_uint, &nid))
                         impossible("relink_light_sources: no id mapping");
                 } else
                     nid = ls->id.a_uint;
                 if (ls->type == LS_OBJECT) {
                     which = 'o';
                     ls->id.a_obj = find_oid(nid);
                 } else {
                     which = 'm';
                     ls->id.a_monst = find_mid(nid, FM_EVERYWHERE);
                 }
                 if (!ls->id.a_monst)
                     impossible("relink_light_sources: cant find %c_id %d",
                                which, nid);
             } else
                 impossible("relink_light_sources: bad type (%d)", ls->type);
 
             ls->flags &= ~LSF_NEEDS_FIXUP;
         }
     }
 }
 

maybe_write_ls

 /*
  * Part of the light source save routine.  Count up the number of light
  * sources that would be written.  If write_it is true, actually write
  * the light source out.
  */
 STATIC_OVL int
 maybe_write_ls(fd, range, write_it)
 int fd, range;
 boolean write_it;
 {
     int count = 0, is_global;
     light_source *ls;
 
     for (ls = light_base; ls; ls = ls->next) {
         if (!ls->id.a_monst) {
             impossible("maybe_write_ls: no id! [range=%d]", range);
             continue;
         }
         switch (ls->type) {
         case LS_OBJECT:
             is_global = !obj_is_local(ls->id.a_obj);
             break;
         case LS_MONSTER:
             is_global = !mon_is_local(ls->id.a_monst);
             break;
         default:
             is_global = 0;
             impossible("maybe_write_ls: bad type (%d) [range=%d]", ls->type,
                        range);
             break;
         }
         /* if global and not doing local, or vice versa, count it */
         if (is_global ^ (range == RANGE_LEVEL)) {
             count++;
             if (write_it)
                 write_ls(fd, ls);
         }
     }
 
     return count;
 }
 

light_sources_sanity_check

 void
 light_sources_sanity_check()
 {
     light_source *ls;
     struct monst *mtmp;
     struct obj *otmp;
     unsigned int auint;
 
     for (ls = light_base; ls; ls = ls->next) {
         if (!ls->id.a_monst)
             panic("insane light source: no id!");
         if (ls->type == LS_OBJECT) {
             otmp = (struct obj *) ls->id.a_obj;
             auint = otmp->o_id;
             if (find_oid(auint) != otmp)
                 panic("insane light source: can't find obj #%u!", auint);
         } else if (ls->type == LS_MONSTER) {
             mtmp = (struct monst *) ls->id.a_monst;
             auint = mtmp->m_id;
             if (find_mid(auint, FM_EVERYWHERE) != mtmp)
                 panic("insane light source: can't find mon #%u!", auint);
         } else {
             panic("insane light source: bad ls type %d", ls->type);
         }
     }
 }
 

write_ls

 /* Write a light source structure to disk. */
 STATIC_OVL void
 write_ls(fd, ls)
 int fd;
 light_source *ls;
 {
     anything arg_save;
     struct obj *otmp;
     struct monst *mtmp;
 
     if (ls->type == LS_OBJECT || ls->type == LS_MONSTER) {
         if (ls->flags & LSF_NEEDS_FIXUP) {
             bwrite(fd, (genericptr_t) ls, sizeof(light_source));
         } else {
             /* replace object pointer with id for write, then put back */
             arg_save = ls->id;
             if (ls->type == LS_OBJECT) {
                 otmp = ls->id.a_obj;
                 ls->id = zeroany;
                 ls->id.a_uint = otmp->o_id;
                 if (find_oid((unsigned) ls->id.a_uint) != otmp)
                     impossible("write_ls: can't find obj #%u!",
                                ls->id.a_uint);
             } else { /* ls->type == LS_MONSTER */
                 mtmp = (struct monst *) ls->id.a_monst;
                 ls->id = zeroany;
                 ls->id.a_uint = mtmp->m_id;
                 if (find_mid((unsigned) ls->id.a_uint, FM_EVERYWHERE) != mtmp)
                     impossible("write_ls: can't find mon #%u!",
                                ls->id.a_uint);
             }
             ls->flags |= LSF_NEEDS_FIXUP;
             bwrite(fd, (genericptr_t) ls, sizeof(light_source));
             ls->id = arg_save;
             ls->flags &= ~LSF_NEEDS_FIXUP;
         }
     } else {
         impossible("write_ls: bad type (%d)", ls->type);
     }
 }
 

obj_move_light_source

 /* Change light source's ID from src to dest. */
 void
 obj_move_light_source(src, dest)
 struct obj *src, *dest;
 {
     light_source *ls;
 
     for (ls = light_base; ls; ls = ls->next)
         if (ls->type == LS_OBJECT && ls->id.a_obj == src)
             ls->id.a_obj = dest;
     src->lamplit = 0;
     dest->lamplit = 1;
 }
 

any_light_source

 /* return true if there exist any light sources */
 boolean
 any_light_source()
 {
     return (boolean) (light_base != (light_source *) 0);
 }
 

snuff_light_source

 /*
  * Snuff an object light source if at (x,y).  This currently works
  * only for burning light sources.
  */
 void
 snuff_light_source(x, y)
 int x, y;
 {
     light_source *ls;
     struct obj *obj;
 
     for (ls = light_base; ls; ls = ls->next)
         /*
          * Is this position check valid??? Can I assume that the positions
          * will always be correct because the objects would have been
          * updated with the last vision update?  [Is that recent enough???]
          */
         if (ls->type == LS_OBJECT && ls->x == x && ls->y == y) {
             obj = ls->id.a_obj;
             if (obj_is_burning(obj)) {
                 /* The only way to snuff Sunsword is to unwield it.  Darkness
                  * scrolls won't affect it.  (If we got here because it was
                  * dropped or thrown inside a monster, this won't matter
                  * anyway because it will go out when dropped.)
                  */
                 if (artifact_light(obj))
                     continue;
                 end_burn(obj, obj->otyp != MAGIC_LAMP);
                 /*
                  * The current ls element has just been removed (and
                  * ls->next is now invalid).  Return assuming that there
                  * is only one light source attached to each object.
                  */
                 return;
             }
         }
 }
 

obj_sheds_light

 /* Return TRUE if object sheds any light at all. */
 boolean
 obj_sheds_light(obj)
 struct obj *obj;
 {
     /* so far, only burning objects shed light */
     return obj_is_burning(obj);
 }
 

obj_is_burning

 /* Return TRUE if sheds light AND will be snuffed by end_burn(). */
 boolean
 obj_is_burning(obj)
 struct obj *obj;
 {
     return (boolean) (obj->lamplit && (obj->otyp == MAGIC_LAMP
                                        || ignitable(obj)
                                        || artifact_light(obj)));
 }
 

obj_split_light_source

 /* copy the light source(s) attached to src, and attach it/them to dest */
 void
 obj_split_light_source(src, dest)
 struct obj *src, *dest;
 {
     light_source *ls, *new_ls;
 
     for (ls = light_base; ls; ls = ls->next)
         if (ls->type == LS_OBJECT && ls->id.a_obj == src) {
             /*
              * Insert the new source at beginning of list.  This will
              * never interfere us walking down the list - we are already
              * past the insertion point.
              */
             new_ls = (light_source *) alloc(sizeof(light_source));
             *new_ls = *ls;
             if (Is_candle(src)) {
                 /* split candles may emit less light than original group */
                 ls->range = candle_light_range(src);
                 new_ls->range = candle_light_range(dest);
                 vision_full_recalc = 1; /* in case range changed */
             }
             new_ls->id.a_obj = dest;
             new_ls->next = light_base;
             light_base = new_ls;
             dest->lamplit = 1; /* now an active light source */
         }
 }
 

obj_merge_light_sources

 /* light source `src' has been folded into light source `dest';
    used for merging lit candles and adding candle(s) to lit candelabrum */
 void
 obj_merge_light_sources(src, dest)
 struct obj *src, *dest;
 {
     light_source *ls;
 
     /* src == dest implies adding to candelabrum */
     if (src != dest)
         end_burn(src, TRUE); /* extinguish candles */
 
     for (ls = light_base; ls; ls = ls->next)
         if (ls->type == LS_OBJECT && ls->id.a_obj == dest) {
             ls->range = candle_light_range(dest);
             vision_full_recalc = 1; /* in case range changed */
             break;
         }
 }
 

obj_adjust_light_radius

 /* light source `obj' is being made brighter or dimmer */
 void
 obj_adjust_light_radius(obj, new_radius)
 struct obj *obj;
 int new_radius;
 {
     light_source *ls;
 
     for (ls = light_base; ls; ls = ls->next)
         if (ls->type == LS_OBJECT && ls->id.a_obj == obj) {
             if (new_radius != ls->range)
                 vision_full_recalc = 1;
             ls->range = new_radius;
             return;
         }
     impossible("obj_adjust_light_radius: can't find %s", xname(obj));
 }
 

candle_light_range

 /* Candlelight is proportional to the number of candles;
    minimum range is 2 rather than 1 for playability. */
 int
 candle_light_range(obj)
 struct obj *obj;
 {
     int radius;
 
     if (obj->otyp == CANDELABRUM_OF_INVOCATION) {
         /*
          *      The special candelabrum emits more light than the
          *      corresponding number of candles would.
          *       1..3 candles, range 2 (minimum range);
          *       4..6 candles, range 3 (normal lamp range);
          *          7 candles, range 4 (bright).
          */
         radius = (obj->spe < 4) ? 2 : (obj->spe < 7) ? 3 : 4;
     } else if (Is_candle(obj)) {
         /*
          *      Range is incremented by powers of 7 so that it will take
          *      wizard mode quantities of candles to get more light than
          *      from a lamp, without imposing an arbitrary limit.
          *       1..6   candles, range 2;
          *       7..48  candles, range 3;
          *      49..342 candles, range 4; &c.
          */
         long n = obj->quan;
 
         radius = 1; /* always incremented at least once */
         do {
             radius++;
             n /= 7L;
         } while (n > 0L);
     } else {
         /* we're only called for lit candelabrum or candles */
         /* impossible("candlelight for %d?", obj->otyp); */
         radius = 3; /* lamp's value */
     }
     return radius;
 }
 

arti_light_radius

 /* light emitting artifact's range depends upon its curse/bless state */
 int
 arti_light_radius(obj)
 struct obj *obj;
 {
     /*
      * Used by begin_burn() when setting up a new light source
      * (obj->lamplit will already be set by this point) and
      * also by bless()/unbless()/uncurse()/curse() to decide
      * whether to call obj_adjust_light_radius().
      */
 
     /* sanity check [simplifies usage by bless()/curse()/&c] */
     if (!obj->lamplit || !artifact_light(obj))
         return 0;
 
     /* cursed radius of 1 is not noticeable for an item that's
        carried by the hero but is if it's carried by a monster
        or left lit on the floor (not applicable for Sunsword) */
     return (obj->blessed ? 3 : !obj->cursed ? 2 : 1);
 }
 

arti_light_description

 /* adverb describing lit artifact's light; depends on curse/bless state */
 const char *
 arti_light_description(obj)
 struct obj *obj;
 {
     switch (arti_light_radius(obj)) {
     case 3:
         return "brilliantly"; /* blessed */
     case 2:
         return "brightly"; /* uncursed */
     case 1:
         return "dimly"; /* cursed */
     default:
         break;
     }
     return "strangely";
 }
 

wiz_light_sources

 int
 wiz_light_sources()
 {
     winid win;
     char buf[BUFSZ];
     light_source *ls;
 
     win = create_nhwindow(NHW_MENU); /* corner text window */
     if (win == WIN_ERR)
         return 0;
 
     Sprintf(buf, "Mobile light sources: hero @ (%2d,%2d)", u.ux, u.uy);
     putstr(win, 0, buf);
     putstr(win, 0, "");
 
     if (light_base) {
         putstr(win, 0, "location range flags  type    id");
         putstr(win, 0, "-------- ----- ------ ----  -------");
         for (ls = light_base; ls; ls = ls->next) {
             Sprintf(buf, "  %2d,%2d   %2d   0x%04x  %s  %s", ls->x, ls->y,
                     ls->range, ls->flags,
                     (ls->type == LS_OBJECT
                        ? "obj"
                        : ls->type == LS_MONSTER
                           ? (mon_is_local(ls->id.a_monst)
                              ? "mon"
                              : (ls->id.a_monst == &youmonst)
                                 ? "you"
                                 /* migrating monster */
                                 : "<m>")
                           : "???"),
                     fmt_ptr(ls->id.a_void));
             putstr(win, 0, buf);
         }
     } else
         putstr(win, 0, "<none>");
 
     display_nhwindow(win, FALSE);
     destroy_nhwindow(win);
 
     return 0;
 }
 
 /*light.c*/