server/common/object.C

/*
    CrossFire, A Multiplayer game for X-windows

    Copyright (C) 2001 Mark Wedel & Crossfire Development Team
    Copyright (C) 1992 Frank Tore Johansen

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

    The authors can be reached via e-mail at <crossfire@schmorp.de>
*/

/* Eneq(@csd.uu.se): Added weight-modifiers in environment of objects.
   sub/add_weight will transcend the environment updating the carrying
   variable. */
#include <global.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <object.h>
#include <funcpoint.h>
#include <loader.h>

#include <bitset>

int nrofallocobjects = 0;
static UUID uuid;
const uint64 UUID_SKIP = 1<<19;

object *active_objects;         /* List of active objects that need to be processed */

short freearr_x[SIZEOFFREE] = { 0, 0, 1, 1, 1, 0, -1, -1, -1, 0, 1, 2, 2, 2, 2, 2, 1, 0, -1, -2, -2, -2, -2, -2, -1,
  0, 1, 2, 3, 3, 3, 3, 3, 3, 3, 2, 1, 0, -1, -2, -3, -3, -3, -3, -3, -3, -3, -2, -1
};
short freearr_y[SIZEOFFREE] = { 0, -1, -1, 0, 1, 1, 1, 0, -1, -2, -2, -2, -1, 0, 1, 2, 2, 2, 2, 2, 1, 0, -1, -2, -2,
  -3, -3, -3, -3, -2, -1, 0, 1, 2, 3, 3, 3, 3, 3, 3, 3, 2, 1, 0, -1, -2, -3, -3, -3
};
int maxfree[SIZEOFFREE] = { 0, 9, 10, 13, 14, 17, 18, 21, 22, 25, 26, 27, 30, 31, 32, 33, 36, 37, 39, 39, 42, 43, 44, 45,
  48, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49
};
int freedir[SIZEOFFREE] = {
  0, 1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 2, 2, 3, 4, 4, 4, 5, 6, 6, 6, 7, 8, 8, 8,
  1, 2, 2, 2, 2, 2, 3, 4, 4, 4, 4, 4, 5, 6, 6, 6, 6, 6, 7, 8, 8, 8, 8, 8
};

static void
write_uuid (void)
{
  char filename1[MAX_BUF], filename2[MAX_BUF];

  sprintf (filename1, "%s/uuid", settings.localdir);
  sprintf (filename2, "%s/uuid~", settings.localdir);

  FILE *fp;

  if (!(fp = fopen (filename2, "w")))
    {
      LOG (llevError, "ERROR: cannot open %s for writing, unable to write UUID!\n", filename2);
      return;
    }

  fprintf (fp, "<1,%llx>\n", (unsigned long long)uuid.seq + UUID_SKIP * 2);
  fclose (fp);
  rename (filename2, filename1);
}

static void
read_uuid (void)
{
  char filename[MAX_BUF];

  sprintf (filename, "%s/uuid", settings.localdir);

  FILE *fp;

  if (!(fp = fopen (filename, "r")))
    {
      if (errno == ENOENT)
        {
          LOG (llevInfo, "RESET uid to 1\n");
          uuid.seq = 0;
          write_uuid ();
          return;
        }

      LOG (llevError, "FATAL: cannot open %s for reading!\n", filename);
      _exit (1);
    }

  int version;
  unsigned long long uid;
  if (2 != fscanf (fp, "<%d,%llx>\n", &version, &uid) || version != 1)
    {
      LOG (llevError, "FATAL: error reading uid from %s!\n", filename);
      _exit (1);
    }

  uuid.seq = uid;
  write_uuid ();
  LOG (llevDebug, "read UID: %" PRId64 "\n", uid);
  fclose (fp);
}

UUID
gen_uuid ()
{
  UUID uid;

  uid.seq = ++uuid.seq;

  if (!(uuid.seq & (UUID_SKIP - 1)))
    write_uuid ();

  return uid;
}

void
init_uuid ()
{
  read_uuid ();
}

/* Returns TRUE if every key_values in wants has a partner with the same value in has. */
static int
compare_ob_value_lists_one (const object *wants, const object *has)
{
  key_value *wants_field;

  /* n-squared behaviour (see get_ob_key_link()), but I'm hoping both
   * objects with lists are rare, and lists stay short. If not, use a
   * different structure or at least keep the lists sorted... 
   */

  /* For each field in wants, */
  for (wants_field = wants->key_values; wants_field != NULL; wants_field = wants_field->next)
    {
      key_value *has_field;

      /* Look for a field in has with the same key. */
      has_field = get_ob_key_link (has, wants_field->key);

      if (has_field == NULL)
        {
          /* No field with that name. */
          return FALSE;
        }

      /* Found the matching field. */
      if (has_field->value != wants_field->value)
        {
          /* Values don't match, so this half of the comparison is false. */
          return FALSE;
        }

      /* If we get here, we found a match. Now for the next field in wants. */
    }

  /* If we get here, every field in wants has a matching field in has. */
  return TRUE;
}

/* Returns TRUE if ob1 has the same key_values as ob2. */
static int
compare_ob_value_lists (const object *ob1, const object *ob2)
{
  /* However, there may be fields in has which aren't partnered in wants,
   * so we need to run the comparison *twice*. :(
   */
  return compare_ob_value_lists_one (ob1, ob2) && compare_ob_value_lists_one (ob2, ob1);
}

/* Function examines the 2 objects given to it, and returns true if
 * they can be merged together.
 *
 * Note that this function appears a lot longer than the macro it
 * replaces - this is mostly for clarity - a decent compiler should hopefully
 * reduce this to the same efficiency.
 *
 * Check nrof variable *before* calling can_merge()
 *
 * Improvements made with merge:  Better checking on potion, and also
 * check weight
 */

bool object::can_merge_slow (object *ob1, object *ob2)
{
  /* A couple quicksanity checks */
  if (ob1 == ob2
      || ob1->type  != ob2->type
      || ob1->speed != ob2->speed
      || ob1->value != ob2->value
      || ob1->name  != ob2->name)
    return 0;

  //TODO: this ain't working well, use nicer and correct overflow check
  /* Do not merge objects if nrof would overflow. We use 1UL<<31 since that
   * value could not be stored in a sint32 (which unfortunately sometimes is
   * used to store nrof).
   */
  if (ob1->nrof + ob2->nrof >= 1UL << 31)
    return 0;

  /* If the objects have been identified, set the BEEN_APPLIED flag.
   * This is to the comparison of the flags below will be OK.  We
   * just can't ignore the been applied or identified flags, as they
   * are not equal - just if it has been identified, the been_applied
   * flags lose any meaning.
   */
  if (QUERY_FLAG (ob1, FLAG_IDENTIFIED))
    SET_FLAG (ob1, FLAG_BEEN_APPLIED);

  if (QUERY_FLAG (ob2, FLAG_IDENTIFIED))
    SET_FLAG (ob2, FLAG_BEEN_APPLIED);

  if ((ob1->flags ^ ob2->flags).reset (FLAG_INV_LOCKED).reset (FLAG_CLIENT_SENT).any ()
      || ob1->arch         != ob2->arch
      || ob1->name         != ob2->name
      || ob1->title        != ob2->title
      || ob1->msg          != ob2->msg
      || ob1->weight       != ob2->weight
      || memcmp (&ob1->resist, &ob2->resist, sizeof (ob1->resist))
      || memcmp (&ob1->stats , &ob2->stats , sizeof (ob1->stats) )
      || ob1->attacktype   != ob2->attacktype
      || ob1->magic        != ob2->magic
      || ob1->slaying      != ob2->slaying
      || ob1->skill        != ob2->skill
      || ob1->value        != ob2->value
      || ob1->animation_id != ob2->animation_id
      || ob1->client_type  != ob2->client_type
      || ob1->materialname != ob2->materialname
      || ob1->lore         != ob2->lore
      || ob1->subtype      != ob2->subtype
      || ob1->move_type    != ob2->move_type
      || ob1->move_block   != ob2->move_block
      || ob1->move_allow   != ob2->move_allow
      || ob1->move_on      != ob2->move_on
      || ob1->move_off     != ob2->move_off
      || ob1->move_slow    != ob2->move_slow
      || ob1->move_slow_penalty != ob2->move_slow_penalty)
    return 0;

  /* This is really a spellbook check - really, we should
   * check all objects in the inventory.
   */
  if (ob1->inv || ob2->inv)
    {
      /* if one object has inventory but the other doesn't, not equiv */
      if ((ob1->inv && !ob2->inv) || (ob2->inv && !ob1->inv))
        return 0;

      /* Now check to see if the two inventory objects could merge */
      if (!object::can_merge (ob1->inv, ob2->inv))
        return 0;

      /* inventory ok - still need to check rest of this object to see
       * if it is valid.
       */
    }

  /* Don't merge objects that are applied.  With the new 'body' code,
   * it is possible for most any character to have more than one of
   * some items equipped, and we don't want those to merge.
   */
  if (QUERY_FLAG (ob1, FLAG_APPLIED) || QUERY_FLAG (ob2, FLAG_APPLIED))
    return 0;

  /* Note sure why the following is the case - either the object has to
   * be animated or have a very low speed.  Is this an attempted monster
   * check?
   */
  if (!QUERY_FLAG (ob1, FLAG_ANIMATE) && FABS ((ob1)->speed) > MIN_ACTIVE_SPEED)
    return 0;

  switch (ob1->type)
    {
      case SCROLL:
        if (ob1->level != ob2->level)
          return 0;
        break;
    }

  if (ob1->key_values != NULL || ob2->key_values != NULL)
    {
      /* At least one of these has key_values. */
      if ((ob1->key_values == NULL) != (ob2->key_values == NULL))
        /* One has fields, but the other one doesn't. */
        return 0;
      else if (!compare_ob_value_lists (ob1, ob2))
        return 0;
    }

  //TODO: generate an event or call into perl for additional checks
  if (ob1->self || ob2->self)
    {
      ob1->optimise ();
      ob2->optimise ();

      if (ob1->self || ob2->self)
        return 0;
    }

  /* Everything passes, must be OK. */
  return 1;
}

/*
 * sum_weight() is a recursive function which calculates the weight
 * an object is carrying.  It goes through in figures out how much
 * containers are carrying, and sums it up.
 */
long
sum_weight (object *op)
{
  long sum;
  object *inv;

  for (sum = 0, inv = op->inv; inv != NULL; inv = inv->below)
    {
      if (inv->inv)
        sum_weight (inv);
      sum += inv->carrying + inv->weight * (inv->nrof ? inv->nrof : 1);
    }

  if (op->type == CONTAINER && op->stats.Str)
    sum = (sum * (100 - op->stats.Str)) / 100;

  if (op->carrying != sum)
    op->carrying = sum;

  return sum;
}

/**
 * Return the outermost environment object for a given object.
 */

object *
object_get_env_recursive (object *op)
{
  while (op->env != NULL)
    op = op->env;
  return op;
}

/*
 * Used by: Crossedit: dump. Server DM commands: dumpbelow, dump.
 *      Some error messages.
 * The result of the dump is stored in the static global errmsg array.
 */

char *
dump_object (object *op)
{
  if (!op)
    return strdup ("[NULLOBJ]");

  object_freezer freezer;
  save_object (freezer, op, 3);
  return freezer.as_string ();
}

/*
 * get_nearest_part(multi-object, object 2) returns the part of the
 * multi-object 1 which is closest to the second object.
 * If it's not a multi-object, it is returned.
 */

object *
get_nearest_part (object *op, const object *pl)
{
  object *tmp, *closest;
  int last_dist, i;

  if (op->more == NULL)
    return op;
  for (last_dist = distance (op, pl), closest = op, tmp = op->more; tmp != NULL; tmp = tmp->more)
    if ((i = distance (tmp, pl)) < last_dist)
      closest = tmp, last_dist = i;
  return closest;
}

/*
 * Returns the object which has the count-variable equal to the argument.
 */

object *
find_object (tag_t i)
{
  for (object *op = object::first; op; op = op->next)
    if (op->count == i)
      return op;

  return 0;
}

/*
 * Returns the first object which has a name equal to the argument.
 * Used only by the patch command, but not all that useful.
 * Enables features like "patch <name-of-other-player> food 999"
 */

object *
find_object_name (const char *str)
{
  shstr_cmp str_ (str);
  object *op;

  for (op = object::first; op != NULL; op = op->next)
    if (op->name == str_)
      break;

  return op;
}

void
free_all_object_data ()
{
  LOG (llevDebug, "%d allocated objects\n", nrofallocobjects);
}

/*
 * Sets the owner and sets the skill and exp pointers to owner's current
 * skill and experience objects.
 */
void
object::set_owner (object *owner)
{
  if (!owner)
    return;

  /* next line added to allow objects which own objects */
  /* Add a check for ownercounts in here, as I got into an endless loop
   * with the fireball owning a poison cloud which then owned the
   * fireball.  I believe that was caused by one of the objects getting
   * freed and then another object replacing it.  Since the ownercounts
   * didn't match, this check is valid and I believe that cause is valid.
   */
  while (owner->owner)
    owner = owner->owner;

  this->owner = owner;
}

/* Zero the key_values on op, decrementing the shared-string
 * refcounts and freeing the links. 
 */
static void
free_key_values (object *op)
{
  for (key_value *i = op->key_values; i != 0;)
    {
      key_value *next = i->next;
      delete i;

      i = next;
    }

  op->key_values = 0;
}

/*
 * copy_to first frees everything allocated by the dst object,
 * and then copies the contents of itself into the second
 * object, allocating what needs to be allocated.  Basically, any
 * data that is malloc'd needs to be re-malloc/copied.  Otherwise,
 * if the first object is freed, the pointers in the new object
 * will point at garbage.
 */
void
object::copy_to (object *dst)
{
  bool is_freed   = QUERY_FLAG (dst, FLAG_FREED);
  bool is_removed = QUERY_FLAG (dst, FLAG_REMOVED);

  *(object_copy *)dst = *this;
  *(object_pod  *)dst = *this;

  if (self || cb)
    INVOKE_OBJECT (CLONE, this, ARG_OBJECT (dst));

  if (is_freed)
    SET_FLAG (dst, FLAG_FREED);

  if (is_removed)
    SET_FLAG (dst, FLAG_REMOVED);

  if (speed < 0)
    dst->speed_left = speed_left - RANDOM () % 200 / 100.0;

  /* Copy over key_values, if any. */
  if (key_values)
    {
      key_value *tail = 0;
      key_value *i;

      dst->key_values = 0;

      for (i = key_values; i; i = i->next)
        {
          key_value *new_link = new key_value;

          new_link->next = 0;
          new_link->key = i->key;
          new_link->value = i->value;

          /* Try and be clever here, too. */
          if (!dst->key_values)
            {
              dst->key_values = new_link;
              tail = new_link;
            }
          else
            {
              tail->next = new_link;
              tail = new_link;
            }
        }
    }

  update_ob_speed (dst);
}

object *
object::clone ()
{
  object *neu = create ();
  copy_to (neu);
  return neu;
}

/*
 * If an object with the IS_TURNABLE() flag needs to be turned due
 * to the closest player being on the other side, this function can
 * be called to update the face variable, _and_ how it looks on the map.
 */

void
update_turn_face (object *op)
{
  if (!QUERY_FLAG (op, FLAG_IS_TURNABLE) || op->arch == NULL)
    return;
  SET_ANIMATION (op, op->direction);
  update_object (op, UP_OBJ_FACE);
}

/*
 * Updates the speed of an object.  If the speed changes from 0 to another
 * value, or vice versa, then add/remove the object from the active list.
 * This function needs to be called whenever the speed of an object changes.
 */
void
update_ob_speed (object *op)
{
  extern int arch_init;

  /* No reason putting the archetypes objects on the speed list,
   * since they never really need to be updated.
   */

  if (QUERY_FLAG (op, FLAG_FREED) && op->speed)
    {
      LOG (llevError, "Object %s is freed but has speed.\n", &op->name);
#ifdef MANY_CORES
      abort ();
#else
      op->speed = 0;
#endif
    }

  if (arch_init)
    return;

  if (FABS (op->speed) > MIN_ACTIVE_SPEED)
    {
      /* If already on active list, don't do anything */
      if (op->active_next || op->active_prev || op == active_objects)
        return;

      /* process_events() expects us to insert the object at the beginning
       * of the list. */
      op->active_next = active_objects;

      if (op->active_next != NULL)
        op->active_next->active_prev = op;

      active_objects = op;
    }
  else
    {
      /* If not on the active list, nothing needs to be done */
      if (!op->active_next && !op->active_prev && op != active_objects)
        return;

      if (op->active_prev == NULL)
        {
          active_objects = op->active_next;

          if (op->active_next != NULL)
            op->active_next->active_prev = NULL;
        }
      else
        {
          op->active_prev->active_next = op->active_next;

          if (op->active_next)
            op->active_next->active_prev = op->active_prev;
        }

      op->active_next = NULL;
      op->active_prev = NULL;
    }
}

/* This function removes object 'op' from the list of active
 * objects.
 * This should only be used for style maps or other such 
 * reference maps where you don't want an object that isn't
 * in play chewing up cpu time getting processed.
 * The reverse of this is to call update_ob_speed, which
 * will do the right thing based on the speed of the object.
 */
void
remove_from_active_list (object *op)
{
  /* If not on the active list, nothing needs to be done */
  if (!op->active_next && !op->active_prev && op != active_objects)
    return;

  if (op->active_prev == NULL)
    {
      active_objects = op->active_next;
      if (op->active_next != NULL)
        op->active_next->active_prev = NULL;
    }
  else
    {
      op->active_prev->active_next = op->active_next;
      if (op->active_next)
        op->active_next->active_prev = op->active_prev;
    }
  op->active_next = NULL;
  op->active_prev = NULL;
}

/*
 * update_object() updates the the map.
 * It takes into account invisible objects (and represent squares covered
 * by invisible objects by whatever is below them (unless it's another
 * invisible object, etc...)
 * If the object being updated is beneath a player, the look-window
 * of that player is updated (this might be a suboptimal way of
 * updating that window, though, since update_object() is called _often_)
 *
 * action is a hint of what the caller believes need to be done.
 * current action are:
 * UP_OBJ_INSERT: op was inserted
 * UP_OBJ_REMOVE: op was removed
 * UP_OBJ_CHANGE: object has somehow changed.  In this case, we always update
 *  as that is easier than trying to look at what may have changed.
 * UP_OBJ_FACE: only the objects face has changed.
 */
void
update_object (object *op, int action)
{
  MoveType move_on, move_off, move_block, move_slow;

  if (op == NULL)
    {
      /* this should never happen */
      LOG (llevDebug, "update_object() called for NULL object.\n");
      return;
    }

  if (op->env)
    {
      /* Animation is currently handled by client, so nothing
       * to do in this case.
       */
      return;
    }

  /* If the map is saving, don't do anything as everything is
   * going to get freed anyways.
   */
  if (!op->map || op->map->in_memory == MAP_SAVING)
    return;

  /* make sure the object is within map boundaries */
  if (op->x < 0 || op->x >= MAP_WIDTH (op->map) || op->y < 0 || op->y >= MAP_HEIGHT (op->map))
    {
      LOG (llevError, "update_object() called for object out of map!\n");
#ifdef MANY_CORES
      abort ();
#endif
      return;
    }

  mapspace &m = op->ms ();

  if (m.flags_ & P_NEED_UPDATE)
    /* nop */;
  else if (action == UP_OBJ_INSERT)
    {
      // this is likely overkill, TODO: revisit (schmorp)
      if ((QUERY_FLAG (op, FLAG_BLOCKSVIEW)  && !(m.flags_ & P_BLOCKSVIEW))
          || (QUERY_FLAG (op, FLAG_NO_MAGIC) && !(m.flags_ & P_NO_MAGIC))
          || (op->type == PLAYER             && !(m.flags_ & P_PLAYER))
          || (op->type == SAFE_GROUND        && !(m.flags_ & P_SAFE))
          || (QUERY_FLAG (op, FLAG_ALIVE)    && !(m.flags_ & P_IS_ALIVE))
          || (QUERY_FLAG (op, FLAG_DAMNED)   && !(m.flags_ & P_NO_CLERIC))
          || (m.move_on   | op->move_on  ) != m.move_on
          || (m.move_off  | op->move_off ) != m.move_off
          || (m.move_slow | op->move_slow) != m.move_slow
          /* This isn't perfect, but I don't expect a lot of objects to
           * to have move_allow right now.    
           */
          || ((m.move_block | op->move_block) & ~op->move_allow) != m.move_block
          || 1) // the above is not strong enough a test to skip updating. los maybe? TODO (Schmorp)
        m.flags_ = P_NEED_UPDATE;
    }
    /* if the object is being removed, we can't make intelligent
     * decisions, because remove_ob can't really pass the object
     * that is being removed.
     */
  else if (action == UP_OBJ_CHANGE || action == UP_OBJ_REMOVE)
    m.flags_ = P_NEED_UPDATE;
  else if (action == UP_OBJ_FACE)
    /* Nothing to do for that case */ ;
  else
    LOG (llevError, "update_object called with invalid action: %d\n", action);

  if (op->more)
    update_object (op->more, action);
}

object::vector object::mortals;
object::vector object::objects; // not yet used
object *object::first;

void object::free_mortals ()
{
  for (AUTODECL (i, mortals.begin ()); i != mortals.end ();)
    if ((*i)->refcnt)
      ++i; // further delay freeing
    else
      {
        delete *i;
        mortals.erase (i);
      }
}

object::object ()
{
  SET_FLAG (this, FLAG_REMOVED);

  expmul = 1.0;
  face = blank_face;
}

object::~object ()
{
  free_key_values (this);
}

void object::link ()
{
  count = ++ob_count;
  uuid = gen_uuid ();

  prev = 0;
  next = object::first;

  if (object::first)
    object::first->prev = this;

  object::first = this;
}

void object::unlink ()
{
  if (this == object::first)
    object::first = next;

  /* Remove this object from the list of used objects */
  if (prev) prev->next = next;
  if (next) next->prev = prev;

  prev = 0;
  next = 0;
}

object *object::create ()
{
  object *op = new object;
  op->link ();
  return op;
}

/*
 * free_object() frees everything allocated by an object, removes
 * it from the list of used objects, and puts it on the list of
 * free objects.  The IS_FREED() flag is set in the object.
 * The object must have been removed by remove_ob() first for
 * this function to succeed.
 *
 * If destroy_inventory is set, free inventory as well. Else drop items in
 * inventory to the ground.
 */
void object::destroy (bool destroy_inventory)
{
  if (QUERY_FLAG (this, FLAG_FREED))
    return;

  if (QUERY_FLAG (this, FLAG_FRIENDLY))
    remove_friendly_object (this);

  if (!QUERY_FLAG (this, FLAG_REMOVED))
    remove ();

  SET_FLAG (this, FLAG_FREED);

  if (more)
    {
      more->destroy (destroy_inventory);
      more = 0;
    }

  if (inv)
    {
      /* Only if the space blocks everything do we not process -
       * if some form of movement is allowed, let objects
       * drop on that space.
       */
      if (destroy_inventory || !map || map->in_memory != MAP_IN_MEMORY || GET_MAP_MOVE_BLOCK (map, x, y) == MOVE_ALL)
        {
          object *op = inv;

          while (op)
            {
              object *tmp = op->below;
              op->destroy (destroy_inventory);
              op = tmp;
            }
        }
      else
        {                       /* Put objects in inventory onto this space */
          object *op = inv;

          while (op)
            {
              object *tmp = op->below;

              op->remove ();

              if (QUERY_FLAG (op, FLAG_STARTEQUIP)
                  || QUERY_FLAG (op, FLAG_NO_DROP) || op->type == RUNE || op->type == TRAP || QUERY_FLAG (op, FLAG_IS_A_TEMPLATE))
                op->destroy ();
              else
                {
                  op->x = x;
                  op->y = y;
                  insert_ob_in_map (op, map, 0, 0);     /* Insert in same map as the envir */
                }

              op = tmp;
            }
        }
    }

  // hack to ensure that freed objects still have a valid map
  {
    static maptile *freed_map; // freed objects are moved here to avoid crashes

    if (!freed_map)
      {
        freed_map = new maptile;

        freed_map->name   = "/internal/freed_objects_map";
        freed_map->width  = 3;
        freed_map->height = 3;

        freed_map->allocate ();
      }

    map = freed_map;
    x = 1;
    y = 1;
  }

  // clear those pointers that likely might have circular references to us
  owner       = 0;
  enemy       = 0;
  attacked_by = 0;

  // only relevant for players(?), but make sure of it anyways
  contr       = 0;

  /* Remove object from the active list */
  speed = 0;
  update_ob_speed (this);

  unlink ();

  mortals.push_back (this);
}

/*
 * sub_weight() recursively (outwards) subtracts a number from the
 * weight of an object (and what is carried by it's environment(s)).
 */
void
sub_weight (object *op, signed long weight)
{
  while (op != NULL)
    {
      if (op->type == CONTAINER)
        weight = (signed long) (weight * (100 - op->stats.Str) / 100);

      op->carrying -= weight;
      op = op->env;
    }
}

/* op->remove ():
 *   This function removes the object op from the linked list of objects
 *   which it is currently tied to.  When this function is done, the
 *   object will have no environment.  If the object previously had an
 *   environment, the x and y coordinates will be updated to
 *   the previous environment.
 *   Beware: This function is called from the editor as well!
 */
void
object::remove ()
{
  object *tmp, *last = 0;
  object *otmp;

  int check_walk_off;

  if (QUERY_FLAG (this, FLAG_REMOVED))
    return;

  SET_FLAG (this, FLAG_REMOVED);

  if (more)
    more->remove ();

  /* 
   * In this case, the object to be removed is in someones
   * inventory.
   */
  if (env)
    {
      if (nrof)
        sub_weight (env, weight * nrof);
      else
        sub_weight (env, weight + carrying);

      /* NO_FIX_PLAYER is set when a great many changes are being
       * made to players inventory.  If set, avoiding the call
       * to save cpu time.
       */
      if ((otmp = in_player ()) && otmp->contr && !QUERY_FLAG (otmp, FLAG_NO_FIX_PLAYER))
        otmp->update_stats ();

      if (above != NULL)
        above->below = below;
      else
        env->inv = below;

      if (below != NULL)
        below->above = above;

      /* we set up values so that it could be inserted into
       * the map, but we don't actually do that - it is up
       * to the caller to decide what we want to do.
       */
      x = env->x, y = env->y;
      map = env->map;
      above = 0, below = 0;
      env = 0;
    }
  else if (map)
    {
      /* Re did the following section of code - it looks like it had
       * lots of logic for things we no longer care about
       */

      /* link the object above us */
      if (above)
        above->below = below;
      else
        map->at (x, y).top = below;       /* we were top, set new top */

      /* Relink the object below us, if there is one */
      if (below)
        below->above = above;
      else
        {
          /* Nothing below, which means we need to relink map object for this space 
           * use translated coordinates in case some oddness with map tiling is
           * evident
           */
          if (GET_MAP_OB (map, x, y) != this)
            {
              char *dump = dump_object (this);
              LOG (llevError,
                   "remove_ob: GET_MAP_OB does not return object to be removed even though it appears to be on the bottom?\n%s\n", dump);
              free (dump);
              dump = dump_object (GET_MAP_OB (map, x, y));
              LOG (llevError, "%s\n", dump);
              free (dump);
            }

          map->at (x, y).bottom = above;      /* goes on above it. */
        }

      above = 0;
      below = 0;

      if (map->in_memory == MAP_SAVING)
        return;

      check_walk_off = !QUERY_FLAG (this, FLAG_NO_APPLY);

      for (tmp = GET_MAP_OB (map, x, y); tmp; tmp = tmp->above)
        {
          /* No point updating the players look faces if he is the object
           * being removed.
           */

          if (tmp->type == PLAYER && tmp != this)
            {
              /* If a container that the player is currently using somehow gets
               * removed (most likely destroyed), update the player view
               * appropriately.
               */
              if (tmp->container == this)
                {
                  CLEAR_FLAG (this, FLAG_APPLIED);
                  tmp->container = 0;
                }

              tmp->contr->ns->floorbox_update ();
            }

          /* See if player moving off should effect something */
          if (check_walk_off
              && ((move_type & tmp->move_off)
                  && (move_type & ~tmp->move_off & ~tmp->move_block) == 0))
            {
              move_apply (tmp, this, 0);

              if (destroyed ())
                LOG (llevError, "BUG: remove_ob(): name %s, destroyed leaving object\n", tmp->debug_desc ());
            }

          /* Eneq(@csd.uu.se): Fixed this to skip tmp->above=tmp */

          if (tmp->above == tmp)
            tmp->above = 0;

          last = tmp;
        }

      /* last == NULL of there are no objects on this space */
      if (!last)
        map->at (x, y).flags_ = P_NEED_UPDATE;
      else
        update_object (last, UP_OBJ_REMOVE);

      if (QUERY_FLAG (this, FLAG_BLOCKSVIEW) || glow_radius)
        update_all_los (map, x, y);
    }
}

/*
 * merge_ob(op,top):
 *
 * This function goes through all objects below and including top, and
 * merges op to the first matching object.
 * If top is NULL, it is calculated.
 * Returns pointer to object if it succeded in the merge, otherwise NULL
 */
object *
merge_ob (object *op, object *top)
{
  if (!op->nrof)
    return 0;

  if (top == NULL)
    for (top = op; top != NULL && top->above != NULL; top = top->above);

  for (; top != NULL; top = top->below)
    {
      if (top == op)
        continue;

      if (object::can_merge (op, top))
        {
          top->nrof += op->nrof;

/*      CLEAR_FLAG(top,FLAG_STARTEQUIP);*/
          op->weight = 0;       /* Don't want any adjustements now */
          op->destroy ();
          return top;
        }
    }

  return 0;
}

/*
 * same as insert_ob_in_map except it handle separate coordinates and do a clean
 * job preparing multi-part monsters
 */
object *
insert_ob_in_map_at (object *op, maptile *m, object *originator, int flag, int x, int y)
{
  object *tmp;

  if (op->head)
    op = op->head;

  for (tmp = op; tmp; tmp = tmp->more)
    {
      tmp->x = x + tmp->arch->clone.x;
      tmp->y = y + tmp->arch->clone.y;
    }

  return insert_ob_in_map (op, m, originator, flag);
}

/*
 * insert_ob_in_map (op, map, originator, flag):
 * This function inserts the object in the two-way linked list
 * which represents what is on a map.
 * The second argument specifies the map, and the x and y variables
 * in the object about to be inserted specifies the position.
 *
 * originator: Player, monster or other object that caused 'op' to be inserted
 * into 'map'.  May be NULL.
 *
 * flag is a bitmask about special things to do (or not do) when this
 * function is called.  see the object.h file for the INS_ values.
 * Passing 0 for flag gives proper default values, so flag really only needs
 * to be set if special handling is needed.
 *
 * Return value:
 *   new object if 'op' was merged with other object
 *   NULL if 'op' was destroyed
 *   just 'op' otherwise
 */

object *
insert_ob_in_map (object *op, maptile *m, object *originator, int flag)
{
  object *tmp, *top, *floor = NULL;
  sint16 x, y;

  if (QUERY_FLAG (op, FLAG_FREED))
    {
      LOG (llevError, "Trying to insert freed object!\n");
      return NULL;
    }

  if (m == NULL)
    {
      char *dump = dump_object (op);
      LOG (llevError, "Trying to insert in null-map!\n%s\n", dump);
      free (dump);
      return op;
    }

  if (out_of_map (m, op->x, op->y))
    {
      char *dump = dump_object (op);
      LOG (llevError, "Trying to insert object outside the map.\n%s\n", dump);
#ifdef MANY_CORES
      /* Better to catch this here, as otherwise the next use of this object
       * is likely to cause a crash.  Better to find out where it is getting
       * improperly inserted.
       */
      abort ();
#endif
      free (dump);
      return op;
    }

  if (!QUERY_FLAG (op, FLAG_REMOVED))
    {
      char *dump = dump_object (op);
      LOG (llevError, "Trying to insert (map) inserted object.\n%s\n", dump);
      free (dump);
      return op;
    }

  if (op->more != NULL)
    {
      /* The part may be on a different map. */

      object *more = op->more;

      /* We really need the caller to normalize coordinates - if
       * we set the map, that doesn't work if the location is within
       * a map and this is straddling an edge.  So only if coordinate
       * is clear wrong do we normalize it.
       */
      if (OUT_OF_REAL_MAP (more->map, more->x, more->y))
        more->map = get_map_from_coord (m, &more->x, &more->y);
      else if (!more->map)
        {
          /* For backwards compatibility - when not dealing with tiled maps,
           * more->map should always point to the parent.
           */
          more->map = m;
        }

      if (insert_ob_in_map (more, more->map, originator, flag) == NULL)
        {
          if (!op->head)
            LOG (llevError, "BUG: insert_ob_in_map(): inserting op->more killed op\n");

          return NULL;
        }
    }

  CLEAR_FLAG (op, FLAG_REMOVED);

  /* Ideally, the caller figures this out.  However, it complicates a lot
   * of areas of callers (eg, anything that uses find_free_spot would now
   * need extra work
   */
  op->map = get_map_from_coord (m, &op->x, &op->y);
  x = op->x;
  y = op->y;

  /* this has to be done after we translate the coordinates.
   */
  if (op->nrof && !(flag & INS_NO_MERGE))
    for (tmp = GET_MAP_OB (op->map, x, y); tmp != NULL; tmp = tmp->above)
      if (object::can_merge (op, tmp))
        {
          op->nrof += tmp->nrof;
          tmp->destroy ();
        }

  CLEAR_FLAG (op, FLAG_APPLIED);        /* hack for fixing F_APPLIED in items of dead people */
  CLEAR_FLAG (op, FLAG_INV_LOCKED);

  if (!QUERY_FLAG (op, FLAG_ALIVE))
    CLEAR_FLAG (op, FLAG_NO_STEAL);

  if (flag & INS_BELOW_ORIGINATOR)
    {
      if (originator->map != op->map || originator->x != op->x || originator->y != op->y)
        {
          LOG (llevError, "insert_ob_in_map called with INS_BELOW_ORIGINATOR when originator not on same space!\n");
          abort ();
        }

      op->above = originator;
      op->below = originator->below;

      if (op->below)
        op->below->above = op;
      else
        op->ms ().bottom = op;

      /* since *below* originator, no need to update top */
      originator->below = op;
    }
  else
    {
      /* If there are other objects, then */
      if ((!(flag & INS_MAP_LOAD)) && ((top = GET_MAP_OB (op->map, op->x, op->y)) != NULL))
        {
          object *last = NULL;

          /*
           * If there are multiple objects on this space, we do some trickier handling.
           * We've already dealt with merging if appropriate.
           * Generally, we want to put the new object on top. But if
           * flag contains INS_ABOVE_FLOOR_ONLY, once we find the last
           * floor, we want to insert above that and no further.
           * Also, if there are spell objects on this space, we stop processing
           * once we get to them.  This reduces the need to traverse over all of 
           * them when adding another one - this saves quite a bit of cpu time
           * when lots of spells are cast in one area.  Currently, it is presumed
           * that flying non pickable objects are spell objects.
           */

          while (top != NULL)
            {
              if (QUERY_FLAG (top, FLAG_IS_FLOOR) || QUERY_FLAG (top, FLAG_OVERLAY_FLOOR))
                floor = top;

              if (QUERY_FLAG (top, FLAG_NO_PICK) && (top->move_type & (MOVE_FLY_LOW | MOVE_FLY_HIGH)) && !QUERY_FLAG (top, FLAG_IS_FLOOR))
                {
                  /* We insert above top, so we want this object below this */
                  top = top->below;
                  break;
                }

              last = top;
              top = top->above;
            }

          /* Don't want top to be NULL, so set it to the last valid object */
          top = last;

          /* We let update_position deal with figuring out what the space
           * looks like instead of lots of conditions here.
           * makes things faster, and effectively the same result.
           */

          /* Have object 'fall below' other objects that block view.
           * Unless those objects are exits, type 66
           * If INS_ON_TOP is used, don't do this processing
           * Need to find the object that in fact blocks view, otherwise
           * stacking is a bit odd.
           */
          if (!(flag & INS_ON_TOP) &&
              (get_map_flags (op->map, 0, op->x, op->y, 0, 0) & P_BLOCKSVIEW) && (op->face && !op->face->visibility))
            {
              for (last = top; last != floor; last = last->below)
                if (QUERY_FLAG (last, FLAG_BLOCKSVIEW) && (last->type != EXIT))
                  break;
              /* Check to see if we found the object that blocks view,
               * and make sure we have a below pointer for it so that
               * we can get inserted below this one, which requires we
               * set top to the object below us.
               */
              if (last && last->below && last != floor)
                top = last->below;
            }
        }                       /* If objects on this space */

      if (flag & INS_MAP_LOAD)
        top = GET_MAP_TOP (op->map, op->x, op->y);

      if (flag & INS_ABOVE_FLOOR_ONLY)
        top = floor;

      /* Top is the object that our object (op) is going to get inserted above.
       */

      /* First object on this space */
      if (!top)
        {
          op->above = GET_MAP_OB (op->map, op->x, op->y);

          if (op->above)
            op->above->below = op;

          op->below = NULL;
          op->ms ().bottom = op;
        }
      else
        {                       /* get inserted into the stack above top */
          op->above = top->above;

          if (op->above)
            op->above->below = op;

          op->below = top;
          top->above = op;
        }

      if (op->above == NULL)
        op->ms ().top = op;
    }                           /* else not INS_BELOW_ORIGINATOR */

  if (op->type == PLAYER)
    op->contr->do_los = 1;

  /* If we have a floor, we know the player, if any, will be above
   * it, so save a few ticks and start from there.
   */
  if (!(flag & INS_MAP_LOAD))
    if (object *pl = op->ms ().player ())
      pl->contr->ns->floorbox_update ();

  /* If this object glows, it may affect lighting conditions that are
   * visible to others on this map.  But update_all_los is really
   * an inefficient way to do this, as it means los for all players
   * on the map will get recalculated.  The players could very well
   * be far away from this change and not affected in any way -
   * this should get redone to only look for players within range,
   * or just updating the P_NEED_UPDATE for spaces within this area
   * of effect may be sufficient.
   */
  if (MAP_DARKNESS (op->map) && (op->glow_radius != 0))
    update_all_los (op->map, op->x, op->y);

  /* updates flags (blocked, alive, no magic, etc) for this map space */
  update_object (op, UP_OBJ_INSERT);

  /* Don't know if moving this to the end will break anything.  However,
   * we want to have floorbox_update called before calling this.
   *
   * check_move_on() must be after this because code called from
   * check_move_on() depends on correct map flags (so functions like
   * blocked() and wall() work properly), and these flags are updated by
   * update_object().
   */

  /* if this is not the head or flag has been passed, don't check walk on status */
  if (!(flag & INS_NO_WALK_ON) && !op->head)
    {
      if (check_move_on (op, originator))
        return NULL;

      /* If we are a multi part object, lets work our way through the check
       * walk on's.
       */
      for (tmp = op->more; tmp != NULL; tmp = tmp->more)
        if (check_move_on (tmp, originator))
          return NULL;
    }

  return op;
}

/* this function inserts an object in the map, but if it
 * finds an object of its own type, it'll remove that one first. 
 * op is the object to insert it under: supplies x and the map.
 */
void
replace_insert_ob_in_map (const char *arch_string, object *op)
{
  object *tmp, *tmp1;

  /* first search for itself and remove any old instances */

  for (tmp = GET_MAP_OB (op->map, op->x, op->y); tmp != NULL; tmp = tmp->above)
    if (!strcmp (tmp->arch->name, arch_string))       /* same archetype */
      tmp->destroy ();

  tmp1 = arch_to_object (archetype::find (arch_string));

  tmp1->x = op->x;
  tmp1->y = op->y;
  insert_ob_in_map (tmp1, op->map, op, 0);
}

/*
 * get_split_ob(ob,nr) splits up ob into two parts.  The part which
 * is returned contains nr objects, and the remaining parts contains
 * the rest (or is removed and freed if that number is 0).
 * On failure, NULL is returned, and the reason put into the
 * global static errmsg array.
 */

object *
get_split_ob (object *orig_ob, uint32 nr)
{
  object *newob;
  int is_removed = (QUERY_FLAG (orig_ob, FLAG_REMOVED) != 0);

  if (orig_ob->nrof < nr)
    {
      sprintf (errmsg, "There are only %d %ss.", orig_ob->nrof ? orig_ob->nrof : 1, &orig_ob->name);
      return NULL;
    }

  newob = object_create_clone (orig_ob);

  if ((orig_ob->nrof -= nr) < 1)
    orig_ob->destroy (1);
  else if (!is_removed)
    {
      if (orig_ob->env != NULL)
        sub_weight (orig_ob->env, orig_ob->weight * nr);
      if (orig_ob->env == NULL && orig_ob->map->in_memory != MAP_IN_MEMORY)
        {
          strcpy (errmsg, "Tried to split object whose map is not in memory.");
          LOG (llevDebug, "Error, Tried to split object whose map is not in memory.\n");
          return NULL;
        }
    }

  newob->nrof = nr;

  return newob;
}

/*
 * decrease_ob_nr(object, number) decreases a specified number from
 * the amount of an object.  If the amount reaches 0, the object
 * is subsequently removed and freed.
 *
 * Return value: 'op' if something is left, NULL if the amount reached 0
 */

object *
decrease_ob_nr (object *op, uint32 i)
{
  object *tmp;
  player *pl;

  if (i == 0)                   /* objects with op->nrof require this check */
    return op;

  if (i > op->nrof)
    i = op->nrof;

  if (QUERY_FLAG (op, FLAG_REMOVED))
    op->nrof -= i;
  else if (op->env)
    {
      /* is this object in the players inventory, or sub container
       * therein?
       */
      tmp = op->in_player ();
      /* nope.  Is this a container the player has opened?
       * If so, set tmp to that player.
       * IMO, searching through all the players will mostly
       * likely be quicker than following op->env to the map,
       * and then searching the map for a player.
       */
      if (!tmp)
        {
          for (pl = first_player; pl; pl = pl->next)
            if (pl->ob->container == op->env)
              {
                tmp = pl->ob;
                break;
              }
        }

      if (i < op->nrof)
        {
          sub_weight (op->env, op->weight * i);
          op->nrof -= i;
          if (tmp)
            esrv_send_item (tmp, op);
        }
      else
        {
          op->remove ();
          op->nrof = 0;
          if (tmp)
            esrv_del_item (tmp->contr, op->count);
        }
    }
  else
    {
      object *above = op->above;

      if (i < op->nrof)
        op->nrof -= i;
      else
        {
          op->remove ();
          op->nrof = 0;
        }

      /* Since we just removed op, op->above is null */
      for (tmp = above; tmp; tmp = tmp->above)
        if (tmp->type == PLAYER)
          {
            if (op->nrof)
              esrv_send_item (tmp, op);
            else
              esrv_del_item (tmp->contr, op->count);
          }
    }

  if (op->nrof)
    return op;
  else
    {
      op->destroy ();
      return 0;
    }
}

/*
 * add_weight(object, weight) adds the specified weight to an object,
 * and also updates how much the environment(s) is/are carrying.
 */

void
add_weight (object *op, signed long weight)
{
  while (op != NULL)
    {
      if (op->type == CONTAINER)
        weight = (signed long) (weight * (100 - op->stats.Str) / 100);

      op->carrying += weight;
      op = op->env;
    }
}

object *
insert_ob_in_ob (object *op, object *where)
{
  if (!where)
    {
      char *dump = dump_object (op);
      LOG (llevError, "Trying to put object in NULL.\n%s\n", dump);
      free (dump);
      return op;
    }

  if (where->head)
    {
      LOG (llevDebug, "Warning: Tried to insert object into wrong part of multipart object.\n");
      where = where->head;
    }

  return where->insert (op);
}

/*
 * env->insert (op)
 *   This function inserts the object op in the linked list
 *   inside the object environment.
 *
 * The function returns now pointer to inserted item, and return value can 
 * be != op, if items are merged. -Tero
 */

object *
object::insert (object *op)
{
  object *tmp, *otmp;

  if (!QUERY_FLAG (op, FLAG_REMOVED))
    op->remove ();

  if (op->more)
    {
      LOG (llevError, "Tried to insert multipart object %s (%d)\n", &op->name, op->count);
      return op;
    }

  CLEAR_FLAG (op, FLAG_OBJ_ORIGINAL);
  CLEAR_FLAG (op, FLAG_REMOVED);
  if (op->nrof)
    {
      for (tmp = inv; tmp != NULL; tmp = tmp->below)
        if (object::can_merge (tmp, op))
          {
            /* return the original object and remove inserted object
               (client needs the original object) */
            tmp->nrof += op->nrof;
            /* Weight handling gets pretty funky.  Since we are adding to
             * tmp->nrof, we need to increase the weight.
             */
            add_weight (this, op->weight * op->nrof);
            SET_FLAG (op, FLAG_REMOVED);
            op->destroy ();   /* free the inserted object */
            op = tmp;
            op->remove ();     /* and fix old object's links */
            CLEAR_FLAG (op, FLAG_REMOVED);
            break;
          }

      /* I assume combined objects have no inventory
       * We add the weight - this object could have just been removed
       * (if it was possible to merge).  calling remove_ob will subtract
       * the weight, so we need to add it in again, since we actually do
       * the linking below
       */
      add_weight (this, op->weight * op->nrof);
    }
  else
    add_weight (this, (op->weight + op->carrying));

  otmp = this->in_player ();
  if (otmp && otmp->contr)
    if (!QUERY_FLAG (otmp, FLAG_NO_FIX_PLAYER))
      otmp->update_stats ();

  op->map = 0;
  op->env = this;
  op->above = 0;
  op->below = 0;
  op->x = 0, op->y = 0;

  /* reset the light list and los of the players on the map */
  if ((op->glow_radius != 0) && map)
    {
#ifdef DEBUG_LIGHTS
      LOG (llevDebug, " insert_ob_in_ob(): got %s to insert in map/op\n", op->name);
#endif /* DEBUG_LIGHTS */
      if (MAP_DARKNESS (map))
        update_all_los (map, x, y);
    }

  /* Client has no idea of ordering so lets not bother ordering it here.
   * It sure simplifies this function...
   */
  if (!inv)
    inv = op;
  else
    {
      op->below = inv;
      op->below->above = op;
      inv = op;
    }

  return op;
}

/*
 * Checks if any objects has a move_type that matches objects
 * that effect this object on this space.  Call apply() to process
 * these events.
 *
 * Any speed-modification due to SLOW_MOVE() of other present objects
 * will affect the speed_left of the object.
 *
 * originator: Player, monster or other object that caused 'op' to be inserted
 * into 'map'.  May be NULL.
 *
 * Return value: 1 if 'op' was destroyed, 0 otherwise.
 *
 * 4-21-95 added code to check if appropriate skill was readied - this will
 * permit faster movement by the player through this terrain. -b.t.
 *
 * MSW 2001-07-08: Check all objects on space, not just those below
 * object being inserted.  insert_ob_in_map may not put new objects
 * on top.
 */

int
check_move_on (object *op, object *originator)
{
  object *tmp;
  maptile *m = op->map;
  int x = op->x, y = op->y;

  MoveType move_on, move_slow, move_block;

  if (QUERY_FLAG (op, FLAG_NO_APPLY))
    return 0;

  move_on = GET_MAP_MOVE_ON (op->map, op->x, op->y);
  move_slow = GET_MAP_MOVE_SLOW (op->map, op->x, op->y);
  move_block = GET_MAP_MOVE_BLOCK (op->map, op->x, op->y);

  /* if nothing on this space will slow op down or be applied,
   * no need to do checking below.    have to make sure move_type
   * is set, as lots of objects don't have it set - we treat that
   * as walking.
   */
  if (op->move_type && !(op->move_type & move_on) && !(op->move_type & move_slow))
    return 0;

  /* This is basically inverse logic of that below - basically,
   * if the object can avoid the move on or slow move, they do so,
   * but can't do it if the alternate movement they are using is
   * blocked.  Logic on this seems confusing, but does seem correct.
   */
  if ((op->move_type & ~move_on & ~move_block) != 0 && (op->move_type & ~move_slow & ~move_block) != 0)
    return 0;

  /* The objects have to be checked from top to bottom.
   * Hence, we first go to the top: 
   */

  for (tmp = GET_MAP_OB (op->map, op->x, op->y); tmp != NULL && tmp->above != NULL; tmp = tmp->above)
    {
      /* Trim the search when we find the first other spell effect 
       * this helps performance so that if a space has 50 spell objects,
       * we don't need to check all of them.
       */
      if ((tmp->move_type & MOVE_FLY_LOW) && QUERY_FLAG (tmp, FLAG_NO_PICK))
        break;
    }

  for (; tmp; tmp = tmp->below)
    {
      if (tmp == op)
        continue;               /* Can't apply yourself */

      /* Check to see if one of the movement types should be slowed down.
       * Second check makes sure that the movement types not being slowed
       * (~slow_move) is not blocked on this space - just because the
       * space doesn't slow down swimming (for example), if you can't actually
       * swim on that space, can't use it to avoid the penalty.
       */
      if (!QUERY_FLAG (op, FLAG_WIZPASS))
        {
          if ((!op->move_type && tmp->move_slow & MOVE_WALK) ||
              ((op->move_type & tmp->move_slow) && (op->move_type & ~tmp->move_slow & ~tmp->move_block) == 0))
            {

              float
                diff = tmp->move_slow_penalty * FABS (op->speed);

              if (op->type == PLAYER)
                if ((QUERY_FLAG (tmp, FLAG_IS_HILLY) && find_skill_by_number (op, SK_CLIMBING)) ||
                    (QUERY_FLAG (tmp, FLAG_IS_WOODED) && find_skill_by_number (op, SK_WOODSMAN)))
                  diff /= 4.0;

              op->speed_left -= diff;
            }
        }

      /* Basically same logic as above, except now for actual apply. */
      if ((!op->move_type && tmp->move_on & MOVE_WALK) ||
          ((op->move_type & tmp->move_on) && (op->move_type & ~tmp->move_on & ~tmp->move_block) == 0))
        {
          move_apply (tmp, op, originator);

          if (op->destroyed ())
            return 1;

          /* what the person/creature stepped onto has moved the object
           * someplace new.  Don't process any further - if we did,
           * have a feeling strange problems would result.
           */
          if (op->map != m || op->x != x || op->y != y)
            return 0;
        }
    }

  return 0;
}

/*
 * present_arch(arch, map, x, y) searches for any objects with
 * a matching archetype at the given map and coordinates.
 * The first matching object is returned, or NULL if none.
 */

object *
present_arch (const archetype *at, maptile *m, int x, int y)
{
  object *
    tmp;

  if (m == NULL || out_of_map (m, x, y))
    {
      LOG (llevError, "Present_arch called outside map.\n");
      return NULL;
    }
  for (tmp = GET_MAP_OB (m, x, y); tmp != NULL; tmp = tmp->above)
    if (tmp->arch == at)
      return tmp;
  return NULL;
}

/*
 * present(type, map, x, y) searches for any objects with
 * a matching type variable at the given map and coordinates.
 * The first matching object is returned, or NULL if none.
 */

object *
present (unsigned char type, maptile *m, int x, int y)
{
  object *
    tmp;

  if (out_of_map (m, x, y))
    {
      LOG (llevError, "Present called outside map.\n");
      return NULL;
    }
  for (tmp = GET_MAP_OB (m, x, y); tmp != NULL; tmp = tmp->above)
    if (tmp->type == type)
      return tmp;
  return NULL;
}

/*
 * present_in_ob(type, object) searches for any objects with
 * a matching type variable in the inventory of the given object.
 * The first matching object is returned, or NULL if none.
 */

object *
present_in_ob (unsigned char type, const object *op)
{
  object *
    tmp;

  for (tmp = op->inv; tmp != NULL; tmp = tmp->below)
    if (tmp->type == type)
      return tmp;
  return NULL;
}

/*
 * present_in_ob (type, str, object) searches for any objects with
 * a matching type & name variable in the inventory of the given object.
 * The first matching object is returned, or NULL if none.
 * This is mostly used by spell effect code, so that we only
 * have one spell effect at a time.
 * type can be used to narrow the search - if type is set,
 * the type must also match.  -1 can be passed for the type,
 * in which case the type does not need to pass.
 * str is the string to match against.  Note that we match against
 * the object name, not the archetype name.  this is so that the
 * spell code can use one object type (force), but change it's name
 * to be unique.
 */

object *
present_in_ob_by_name (int type, const char *str, const object *op)
{
  object *
    tmp;

  for (tmp = op->inv; tmp != NULL; tmp = tmp->below)
    {
      if ((type == -1 || tmp->type == type) && (!strcmp (str, tmp->name)))
        return tmp;
    }
  return NULL;
}

/*
 * present_arch_in_ob(archetype, object) searches for any objects with
 * a matching archetype in the inventory of the given object.
 * The first matching object is returned, or NULL if none.
 */

object *
present_arch_in_ob (const archetype *at, const object *op)
{
  object *
    tmp;

  for (tmp = op->inv; tmp != NULL; tmp = tmp->below)
    if (tmp->arch == at)
      return tmp;
  return NULL;
}

/*
 * activate recursively a flag on an object inventory
 */
void
flag_inv (object *op, int flag)
{
  object *
    tmp;

  if (op->inv)
    for (tmp = op->inv; tmp != NULL; tmp = tmp->below)
      {
        SET_FLAG (tmp, flag);
        flag_inv (tmp, flag);
      }
}                               /*
                                 * desactivate recursively a flag on an object inventory
                                 */
void
unflag_inv (object *op, int flag)
{
  object *
    tmp;

  if (op->inv)
    for (tmp = op->inv; tmp != NULL; tmp = tmp->below)
      {
        CLEAR_FLAG (tmp, flag);
        unflag_inv (tmp, flag);
      }
}

/*
 * set_cheat(object) sets the cheat flag (WAS_WIZ) in the object and in
 * all it's inventory (recursively).
 * If checksums are used, a player will get set_cheat called for
 * him/her-self and all object carried by a call to this function.
 */

void
set_cheat (object *op)
{
  SET_FLAG (op, FLAG_WAS_WIZ);
  flag_inv (op, FLAG_WAS_WIZ);
}

/*
 * find_free_spot(object, map, x, y, start, stop) will search for
 * a spot at the given map and coordinates which will be able to contain
 * the given object.  start and stop specifies how many squares
 * to search (see the freearr_x/y[] definition).
 * It returns a random choice among the alternatives found.
 * start and stop are where to start relative to the free_arr array (1,9
 * does all 4 immediate directions).  This returns the index into the
 * array of the free spot, -1 if no spot available (dir 0 = x,y)
 * Note - this only checks to see if there is space for the head of the
 * object - if it is a multispace object, this should be called for all
 * pieces.
 * Note2: This function does correctly handle tiled maps, but does not
 * inform the caller.  However, insert_ob_in_map will update as
 * necessary, so the caller shouldn't need to do any special work.
 * Note - updated to take an object instead of archetype - this is necessary
 * because arch_blocked (now ob_blocked) needs to know the movement type
 * to know if the space in question will block the object.  We can't use
 * the archetype because that isn't correct if the monster has been 
 * customized, changed states, etc.
 */

int
find_free_spot (const object *ob, maptile *m, int x, int y, int start, int stop)
{
  int
    i,
    index = 0, flag;
  static int
    altern[SIZEOFFREE];

  for (i = start; i < stop; i++)
    {
      flag = ob_blocked (ob, m, x + freearr_x[i], y + freearr_y[i]);
      if (!flag)
        altern[index++] = i;

      /* Basically, if we find a wall on a space, we cut down the search size.
       * In this way, we won't return spaces that are on another side of a wall.
       * This mostly work, but it cuts down the search size in all directions - 
       * if the space being examined only has a wall to the north and empty
       * spaces in all the other directions, this will reduce the search space
       * to only the spaces immediately surrounding the target area, and
       * won't look 2 spaces south of the target space.
       */
      else if ((flag & P_NO_PASS) && maxfree[i] < stop)
        stop = maxfree[i];
    }

  if (!index)
    return -1;

  return altern[RANDOM () % index];
}

/*
 * find_first_free_spot(archetype, maptile, x, y) works like
 * find_free_spot(), but it will search max number of squares.
 * But it will return the first available spot, not a random choice.
 * Changed 0.93.2: Have it return -1 if there is no free spot available.
 */

int
find_first_free_spot (const object *ob, maptile *m, int x, int y)
{
  int
    i;

  for (i = 0; i < SIZEOFFREE; i++)
    {
      if (!ob_blocked (ob, m, x + freearr_x[i], y + freearr_y[i]))
        return i;
    }
  return -1;
}

/*
 * The function permute(arr, begin, end) randomly reorders the array
 * arr[begin..end-1].
 */
static void
permute (int *arr, int begin, int end)
{
  int
    i,
    j,
    tmp,
    len;

  len = end - begin;
  for (i = begin; i < end; i++)
    {
      j = begin + RANDOM () % len;

      tmp = arr[i];
      arr[i] = arr[j];
      arr[j] = tmp;
    }
}

/* new function to make monster searching more efficient, and effective! 
 * This basically returns a randomized array (in the passed pointer) of
 * the spaces to find monsters.  In this way, it won't always look for
 * monsters to the north first.  However, the size of the array passed
 * covers all the spaces, so within that size, all the spaces within
 * the 3x3 area will be searched, just not in a predictable order.
 */
void
get_search_arr (int *search_arr)
{
  int
    i;

  for (i = 0; i < SIZEOFFREE; i++)
    {
      search_arr[i] = i;
    }

  permute (search_arr, 1, SIZEOFFREE1 + 1);
  permute (search_arr, SIZEOFFREE1 + 1, SIZEOFFREE2 + 1);
  permute (search_arr, SIZEOFFREE2 + 1, SIZEOFFREE);
}

/*
 * find_dir(map, x, y, exclude) will search some close squares in the
 * given map at the given coordinates for live objects.
 * It will not considered the object given as exclude among possible
 * live objects.
 * It returns the direction toward the first/closest live object if finds
 * any, otherwise 0.
 * Perhaps incorrectly, but I'm making the assumption that exclude
 * is actually want is going to try and move there.  We need this info
 * because we have to know what movement the thing looking to move
 * there is capable of.
 */

int
find_dir (maptile *m, int x, int y, object *exclude)
{
  int
    i,
    max = SIZEOFFREE, mflags;

  sint16 nx, ny;
  object *
    tmp;
  maptile *
    mp;

  MoveType blocked, move_type;

  if (exclude && exclude->head)
    {
      exclude = exclude->head;
      move_type = exclude->move_type;
    }
  else
    {
      /* If we don't have anything, presume it can use all movement types. */
      move_type = MOVE_ALL;
    }

  for (i = 1; i < max; i++)
    {
      mp = m;
      nx = x + freearr_x[i];
      ny = y + freearr_y[i];

      mflags = get_map_flags (m, &mp, nx, ny, &nx, &ny);

      if (mflags & P_OUT_OF_MAP)
        max = maxfree[i];
      else
        {
          blocked = GET_MAP_MOVE_BLOCK (mp, nx, ny);

          if ((move_type & blocked) == move_type)
            max = maxfree[i];
          else if (mflags & P_IS_ALIVE)
            {
              for (tmp = GET_MAP_OB (mp, nx, ny); tmp; tmp = tmp->above)
                if ((QUERY_FLAG (tmp, FLAG_MONSTER) || tmp->type == PLAYER) && (tmp != exclude || (tmp->head && tmp->head != exclude)))
                  break;

              if (tmp)
                return freedir[i];
            }
        }
    }

  return 0;
}

/*
 * distance(object 1, object 2) will return the square of the
 * distance between the two given objects.
 */

int
distance (const object *ob1, const object *ob2)
{
  int i;

  i = (ob1->x - ob2->x) * (ob1->x - ob2->x) + (ob1->y - ob2->y) * (ob1->y - ob2->y);
  return i;
}

/*
 * find_dir_2(delta-x,delta-y) will return a direction in which
 * an object which has subtracted the x and y coordinates of another
 * object, needs to travel toward it.
 */

int
find_dir_2 (int x, int y)
{
  int q;

  if (y)
    q = x * 100 / y;
  else if (x)
    q = -300 * x;
  else
    return 0;

  if (y > 0)
    {
      if (q < -242)
        return 3;
      if (q < -41)
        return 2;
      if (q < 41)
        return 1;
      if (q < 242)
        return 8;
      return 7;
    }

  if (q < -242)
    return 7;
  if (q < -41)
    return 6;
  if (q < 41)
    return 5;
  if (q < 242)
    return 4;

  return 3;
}

/*
 * absdir(int): Returns a number between 1 and 8, which represent
 * the "absolute" direction of a number (it actually takes care of
 * "overflow" in previous calculations of a direction).
 */

int
absdir (int d)
{
  while (d < 1)
    d += 8;
  while (d > 8)
    d -= 8;
  return d;
}

/*
 * dirdiff(dir1, dir2) returns how many 45-degrees differences there is
 * between two directions (which are expected to be absolute (see absdir())
 */

int
dirdiff (int dir1, int dir2)
{
  int
    d;

  d = abs (dir1 - dir2);
  if (d > 4)
    d = 8 - d;
  return d;
}

/* peterm:
 * do LOS stuff for ball lightning.  Go after the closest VISIBLE monster.
 * Basically, this is a table of directions, and what directions
 * one could go to go back to us.  Eg, entry 15 below is 4, 14, 16.
 * This basically means that if direction is 15, then it could either go
 * direction 4, 14, or 16 to get back to where we are.
 * Moved from spell_util.c to object.c with the other related direction
 * functions.
 */

int
  reduction_dir[SIZEOFFREE][3] = {
  {0, 0, 0},                    /* 0 */
  {0, 0, 0},                    /* 1 */
  {0, 0, 0},                    /* 2 */
  {0, 0, 0},                    /* 3 */
  {0, 0, 0},                    /* 4 */
  {0, 0, 0},                    /* 5 */
  {0, 0, 0},                    /* 6 */
  {0, 0, 0},                    /* 7 */
  {0, 0, 0},                    /* 8 */
  {8, 1, 2},                    /* 9 */
  {1, 2, -1},                   /* 10 */
  {2, 10, 12},                  /* 11 */
  {2, 3, -1},                   /* 12 */
  {2, 3, 4},                    /* 13 */
  {3, 4, -1},                   /* 14 */
  {4, 14, 16},                  /* 15 */
  {5, 4, -1},                   /* 16 */
  {4, 5, 6},                    /* 17 */
  {6, 5, -1},                   /* 18 */
  {6, 20, 18},                  /* 19 */
  {7, 6, -1},                   /* 20 */
  {6, 7, 8},                    /* 21 */
  {7, 8, -1},                   /* 22 */
  {8, 22, 24},                  /* 23 */
  {8, 1, -1},                   /* 24 */
  {24, 9, 10},                  /* 25 */
  {9, 10, -1},                  /* 26 */
  {10, 11, -1},                 /* 27 */
  {27, 11, 29},                 /* 28 */
  {11, 12, -1},                 /* 29 */
  {12, 13, -1},                 /* 30 */
  {12, 13, 14},                 /* 31 */
  {13, 14, -1},                 /* 32 */
  {14, 15, -1},                 /* 33 */
  {33, 15, 35},                 /* 34 */
  {16, 15, -1},                 /* 35 */
  {17, 16, -1},                 /* 36 */
  {18, 17, 16},                 /* 37 */
  {18, 17, -1},                 /* 38 */
  {18, 19, -1},                 /* 39 */
  {41, 19, 39},                 /* 40 */
  {19, 20, -1},                 /* 41 */
  {20, 21, -1},                 /* 42 */
  {20, 21, 22},                 /* 43 */
  {21, 22, -1},                 /* 44 */
  {23, 22, -1},                 /* 45 */
  {45, 47, 23},                 /* 46 */
  {23, 24, -1},                 /* 47 */
  {24, 9, -1}
};                              /* 48 */

/* Recursive routine to step back and see if we can
 * find a path to that monster that we found.  If not,
 * we don't bother going toward it.  Returns 1 if we
 * can see a direct way to get it
 * Modified to be map tile aware -.MSW
 */
int
can_see_monsterP (maptile *m, int x, int y, int dir)
{
  sint16 dx, dy;
  int mflags;

  if (dir < 0)
    return 0;                   /* exit condition:  invalid direction */

  dx = x + freearr_x[dir];
  dy = y + freearr_y[dir];

  mflags = get_map_flags (m, &m, dx, dy, &dx, &dy);

  /* This functional arguably was incorrect before - it was
   * checking for P_WALL - that was basically seeing if
   * we could move to the monster - this is being more
   * literal on if we can see it.  To know if we can actually
   * move to the monster, we'd need the monster passed in or
   * at least its move type.
   */
  if (mflags & (P_OUT_OF_MAP | P_BLOCKSVIEW))
    return 0;

  /* yes, can see. */
  if (dir < 9)
    return 1;

  return can_see_monsterP (m, x, y, reduction_dir[dir][0])
         | can_see_monsterP (m, x, y, reduction_dir[dir][1])
         | can_see_monsterP (m, x, y, reduction_dir[dir][2]);
}

/*
 * can_pick(picker, item): finds out if an object is possible to be
 * picked up by the picker.  Returnes 1 if it can be
 * picked up, otherwise 0.
 *
 * Cf 0.91.3 - don't let WIZ's pick up anything - will likely cause
 * core dumps if they do.
 *
 * Add a check so we can't pick up invisible objects (0.93.8)
 */

int
can_pick (const object *who, const object *item)
{
  return                        /*QUERY_FLAG(who,FLAG_WIZ)|| */
    (item->weight > 0 && !QUERY_FLAG (item, FLAG_NO_PICK) &&
     !QUERY_FLAG (item, FLAG_ALIVE) && !item->invisible && (who->type == PLAYER || item->weight < who->weight / 3));
}

/*
 * create clone from object to another
 */
object *
object_create_clone (object *asrc)
{
  object *dst = 0, *tmp, *src, *part, *prev, *item;

  if (!asrc)
    return 0;

  src = asrc;
  if (src->head)
    src = src->head;

  prev = 0;
  for (part = src; part; part = part->more)
    {
      tmp = part->clone ();
      tmp->x -= src->x;
      tmp->y -= src->y;

      if (!part->head)
        {
          dst = tmp;
          tmp->head = 0;
        }
      else
        tmp->head = dst;

      tmp->more = 0;

      if (prev)
        prev->more = tmp;

      prev = tmp;
    }

  for (item = src->inv; item; item = item->below)
    insert_ob_in_ob (object_create_clone (item), dst);

  return dst;
}

/* GROS - Creates an object using a string representing its content.         */
/* Basically, we save the content of the string to a temp file, then call    */
/* load_object on it. I admit it is a highly inefficient way to make things, */
/* but it was simple to make and allows reusing the load_object function.    */
/* Remember not to use load_object_str in a time-critical situation.         */
/* Also remember that multiparts objects are not supported for now.          */

object *
load_object_str (const char *obstr)
{
  object *op;
  char filename[MAX_BUF];

  sprintf (filename, "%s/cfloadobstr2044", settings.tmpdir);

  FILE *tempfile = fopen (filename, "w");

  if (tempfile == NULL)
    {
      LOG (llevError, "Error - Unable to access load object temp file\n");
      return NULL;
    }

  fprintf (tempfile, obstr);
  fclose (tempfile);

  op = object::create ();

  object_thawer thawer (filename);

  if (thawer)
    load_object (thawer, op, 0);

  LOG (llevDebug, " load str completed, object=%s\n", &op->name);
  CLEAR_FLAG (op, FLAG_REMOVED);

  return op;
}

/* This returns the first object in who's inventory that
 * has the same type and subtype match.
 * returns NULL if no match.
 */
object *
find_obj_by_type_subtype (const object *who, int type, int subtype)
{
  object *tmp;

  for (tmp = who->inv; tmp; tmp = tmp->below)
    if (tmp->type == type && tmp->subtype == subtype)
      return tmp;

  return NULL;
}

/* If ob has a field named key, return the link from the list,
 * otherwise return NULL. 
 *
 * key must be a passed in shared string - otherwise, this won't
 * do the desired thing.
 */
key_value *
get_ob_key_link (const object *ob, const char *key)
{
  key_value *link;

  for (link = ob->key_values; link != NULL; link = link->next)
    if (link->key == key)
      return link;

  return NULL;
}

/* 
 * Returns the value of op has an extra_field for key, or NULL.
 *
 * The argument doesn't need to be a shared string.
 *
 * The returned string is shared.
 */
const char *
get_ob_key_value (const object *op, const char *const key)
{
  key_value *link;
  shstr_cmp canonical_key (key);

  if (!canonical_key)
    {
      /* 1. There being a field named key on any object
       *    implies there'd be a shared string to find.
       * 2. Since there isn't, no object has this field.
       * 3. Therefore, *this* object doesn't have this field.
       */
      return 0;
    }

  /* This is copied from get_ob_key_link() above -
   * only 4 lines, and saves the function call overhead.
   */
  for (link = op->key_values; link; link = link->next)
    if (link->key == canonical_key)
      return link->value;

  return 0;
}


/*
 * Updates the canonical_key in op to value.
 *
 * canonical_key is a shared string (value doesn't have to be).
 *
 * Unless add_key is TRUE, it won't add fields, only change the value of existing
 * keys.
 *
 * Returns TRUE on success.
 */
int
set_ob_key_value_s (object *op, const shstr & canonical_key, const char *value, int add_key)
{
  key_value *
    field = NULL, *last = NULL;

  for (field = op->key_values; field != NULL; field = field->next)
    {
      if (field->key != canonical_key)
        {
          last = field;
          continue;
        }

      if (value)
        field->value = value;
      else
        {
          /* Basically, if the archetype has this key set,
           * we need to store the null value so when we save
           * it, we save the empty value so that when we load,
           * we get this value back again.
           */
          if (get_ob_key_link (&op->arch->clone, canonical_key))
            field->value = 0;
          else
            {
              if (last)
                last->next = field->next;
              else
                op->key_values = field->next;

              delete field;
            }
        }
      return TRUE;
    }
  /* IF we get here, key doesn't exist */

  /* No field, we'll have to add it. */

  if (!add_key)
    {
      return FALSE;
    }
  /* There isn't any good reason to store a null
   * value in the key/value list.  If the archetype has
   * this key, then we should also have it, so shouldn't
   * be here.  If user wants to store empty strings,
   * should pass in ""
   */
  if (value == NULL)
    return TRUE;

  field = new key_value;

  field->key = canonical_key;
  field->value = value;
  /* Usual prepend-addition. */
  field->next = op->key_values;
  op->key_values = field;

  return TRUE;
}

/*
 * Updates the key in op to value.
 *
 * If add_key is FALSE, this will only update existing keys,
 * and not add new ones.
 * In general, should be little reason FALSE is ever passed in for add_key
 *
 * Returns TRUE on success.
 */
int
set_ob_key_value (object *op, const char *key, const char *value, int add_key)
{
  shstr key_ (key);

  return set_ob_key_value_s (op, key_, value, add_key);
}

object::depth_iterator::depth_iterator (object *container)
: iterator_base (container)
{
  while (item->inv)
    item = item->inv;
}

void
object::depth_iterator::next ()
{
  if (item->below)
    {
      item = item->below;

      while (item->inv)
        item = item->inv;
    }
  else
    item = item->env;
}

// return a suitable string describing an objetc in enough detail to find it
const char *
object::debug_desc (char *info) const
{
  char info2[256 * 3];
  char *p = info;

  p += snprintf (p, 256, "%d=\"%s%s%s\"",
                 count,
                 &name,
                 title ? " " : "",
                 title ? (const char *)title : "");

  if (env)
    p += snprintf (p, 256, "(in %s)", env->debug_desc (info2));

  if (map)
    p += snprintf (p, 256, "(on %s@%d+%d)", map->path, x, y);

  return info;
}

const char *
object::debug_desc () const
{
  static char info[256 * 3];
  return debug_desc (info);
}

Revision:	1.78
Committed:	Fri Dec 22 16:34:00 2006 UTC (17 years, 5 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.77:	+2 -44 lines
Log Message:	- preliminary check in, stuff is rudimentarily working - moved most of the player creation process into a perl coroutine - changed internal design of player management to not reuse and morph the object in funny ways. should be safer and much nicer to handle. - got rid of some annoying hacks, such as clear() (TODO: get rid of player_pod and other stuff now unnecessary?)