server/server/monster.C

/*
 * This file is part of Crossfire TRT, the Roguelike Realtime MORPG.
 * 
 * Copyright (©) 2005,2006,2007 Marc Alexander Lehmann / Robin Redeker / the Crossfire TRT team
 * Copyright (©) 2002,2007 Mark Wedel & Crossfire Development Team
 * Copyright (©) 1992,2007 Frank Tore Johansen
 * 
 * Crossfire TRT 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 3 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, see <http://www.gnu.org/licenses/>.
 * 
 * The authors can be reached via e-mail to <crossfire@schmorp.de>
 */

#include <global.h>
#include <sproto.h>
#include <spells.h>
#include <skills.h>

#define MIN_MON_RADIUS 3        /* minimum monster detection radius */

/* checks npc->enemy and returns that enemy if still valid,
 * NULL otherwise.
 * this is map tile aware.
 * If this returns an enemy, the range vector rv should also be
 * set to sane values.
 */
object *
check_enemy (object *npc, rv_vector * rv)
{

  /* if this is pet, let him attack the same enemy as his owner
   * TODO: when there is no ower enemy, try to find a target,
   * which CAN attack the owner. */
  if ((npc->attack_movement & HI4) == PETMOVE)
    {
      if (npc->owner == NULL)
        npc->enemy = NULL;
      else if (npc->enemy == NULL)
        npc->enemy = npc->owner->enemy;
    }

  /* periodically, a monster mayu change its target.  Also, if the object
   * has been destroyed, etc, clear the enemy.
   * TODO: this should be changed, because it invokes to attack forced or 
   * attacked monsters to leave the attacker alone, before it is destroyed 
   */
  /* i had removed the random target leave, this invokes problems with friendly
   * objects, getting attacked and defending herself - they don't try to attack
   * again then but perhaps get attack on and on 
   * If we include a aggravated flag in , we can handle evil vs evil and good vs good
   * too. */

  if (npc->enemy)
    {
      /* I broke these if's apart to better be able to see what
       * the grouping checks are.  Code is the same.
       */
      if (QUERY_FLAG (npc->enemy, FLAG_REMOVED) ||
          QUERY_FLAG (npc->enemy, FLAG_FREED) ||
          !on_same_map (npc, npc->enemy) || npc == npc->enemy || QUERY_FLAG (npc, FLAG_NEUTRAL) || QUERY_FLAG (npc->enemy, FLAG_NEUTRAL))
        npc->enemy = NULL;

      else if (QUERY_FLAG (npc, FLAG_FRIENDLY) && ((QUERY_FLAG (npc->enemy, FLAG_FRIENDLY)
                                                    && !(should_arena_attack (npc, npc->owner, npc->enemy)))
                                                   || ((npc->enemy->type == PLAYER) && !(should_arena_attack (npc, npc->owner, npc->enemy)))
                                                   || npc->enemy == npc->owner))
        npc->enemy = NULL;


      else if (!QUERY_FLAG (npc, FLAG_FRIENDLY) && (!QUERY_FLAG (npc->enemy, FLAG_FRIENDLY) && npc->enemy->type != PLAYER))
        npc->enemy = NULL;

      /* I've noticed that pets could sometimes get an arrow as the
       * target enemy - this code below makes sure the enemy is something
       * that should be attacked.  My guess is that the arrow hits
       * the creature/owner, and so the creature then takes that
       * as the enemy to attack.
       */
      else if (!QUERY_FLAG (npc->enemy, FLAG_MONSTER)
               && !QUERY_FLAG (npc->enemy, FLAG_GENERATOR)
               && npc->enemy->type != PLAYER
               && npc->enemy->type != GOLEM)
        npc->enemy = NULL;

    }
  return can_detect_enemy (npc, npc->enemy, rv) ? npc->enemy : NULL;
}

/* Returns the nearest living creature (monster or generator).
 * Modified to deal with tiled maps properly.
 * Also fixed logic so that monsters in the lower directions were more
 * likely to be skipped - instead of just skipping the 'start' number
 * of direction, revisit them after looking at all the other spaces.
 *
 * Note that being this may skip some number of spaces, it will
 * not necessarily find the nearest living creature - it basically
 * chooses one from within a 3 space radius, and since it skips
 * the first few directions, it could very well choose something 
 * 3 spaces away even though something directly north is closer.
 *
 * this function is map tile aware.
 */
object *
find_nearest_living_creature (object *npc)
{
  int i, mflags;
  sint16 nx, ny;
  maptile *m;
  int search_arr[SIZEOFFREE];

  get_search_arr (search_arr);

  for (i = 0; i < SIZEOFFREE; i++)
    {
      /* modified to implement smart searching using search_arr
       * guidance array to determine direction of search order
       */
      nx = npc->x + freearr_x[search_arr[i]];
      ny = npc->y + freearr_y[search_arr[i]];
      m = npc->map;

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

      if (mflags & P_OUT_OF_MAP)
        continue;

      if (mflags & P_IS_ALIVE)
        {
          for (object *tmp = m->at (nx, ny).top; tmp; tmp = tmp->below)
            if (tmp->flag [FLAG_MONSTER] || tmp->flag [FLAG_GENERATOR] || tmp->type == PLAYER)
              if (can_see_monsterP (m, nx, ny, i))
                return tmp;
        }
    }

  return 0;
}

/* Tries to find an enemy for npc.  We pass the range vector since
 * our caller will find the information useful.
 * Currently, only move_monster calls this function.
 * Fix function so that we always make calls to get_rangevector
 * if we have a valid target - function as not doing so in
 * many cases.
 */
object *
find_enemy (object *npc, rv_vector * rv)
{
  object *attacker, *tmp = NULL;

  attacker = npc->attacked_by;  /* save this for later use. This can be a attacker. */
  npc->attacked_by = 0;         /* always clear the attacker entry */

  /* if we berserk, we don't care about others - we attack all we can find */
  if (QUERY_FLAG (npc, FLAG_BERSERK))
    {
      tmp = find_nearest_living_creature (npc);

      if (tmp)
        get_rangevector (npc, tmp, rv, 0);
      return tmp;
    }

  /* Here is the main enemy selection.
   * We want this: if there is an enemy, attack him until its not possible or 
   * one of both is dead.
   * If we have no enemy and we are...
   * a monster: try to find a player, a pet or a friendly monster
   * a friendly: only target a monster which is targeting you first or targeting a player
   * a neutral: fight a attacker (but there should be none), then do nothing
   * a pet: attack player enemy or a monster
   */

  /* pet move */
  if ((npc->attack_movement & HI4) == PETMOVE)
    {
      tmp = get_pet_enemy (npc, rv);

      if (tmp)
        get_rangevector (npc, tmp, rv, 0);

      return tmp;
    }

  /* we check our old enemy. */
  if (!(tmp = check_enemy (npc, rv)))
    {
      if (attacker)             /* if we have an attacker, check him */
        {
          /* TODO: thats not finished */
          /* we don't want a fight evil vs evil or good against non evil */

          if (QUERY_FLAG (npc, FLAG_NEUTRAL) || QUERY_FLAG (attacker, FLAG_NEUTRAL) ||      /* neutral */
              (QUERY_FLAG (npc, FLAG_FRIENDLY) && QUERY_FLAG (attacker, FLAG_FRIENDLY)) ||
              (!QUERY_FLAG (npc, FLAG_FRIENDLY) && (!QUERY_FLAG (attacker, FLAG_FRIENDLY) && attacker->type != PLAYER)))
            CLEAR_FLAG (npc, FLAG_SLEEP);   /* skip it, but lets wakeup */
          else if (on_same_map (npc, attacker))     /* thats the only thing we must know... */
            {
              CLEAR_FLAG (npc, FLAG_SLEEP); /* well, NOW we really should wake up! */
              npc->enemy = attacker;
              return attacker;      /* yes, we face our attacker! */
            }
        }

      /* we have no legal enemy or attacker, so we try to target a new one */
      if (!QUERY_FLAG (npc, FLAG_UNAGGRESSIVE) && !QUERY_FLAG (npc, FLAG_FRIENDLY) && !QUERY_FLAG (npc, FLAG_NEUTRAL))
        {
          npc->enemy = get_nearest_player (npc);
          if (npc->enemy)
            tmp = check_enemy (npc, rv);
        }

    }

  return tmp;
}

/* Sees if this monster should wake up.
 * Currently, this is only called from move_monster, and
 * if enemy is set, then so should be rv.
 * returns 1 if the monster should wake up, 0 otherwise.
 */
int
check_wakeup (object *op, object *enemy, rv_vector * rv)
{
  int radius = op->stats.Wis > MIN_MON_RADIUS ? op->stats.Wis : MIN_MON_RADIUS;

  /* Trim work - if no enemy, no need to do anything below */
  if (!enemy)
    return 0;

  /* blinded monsters can only find nearby objects to attack */
  if (QUERY_FLAG (op, FLAG_BLIND))
    radius = MIN_MON_RADIUS;

  /* This covers the situation where the monster is in the dark 
   * and has an enemy. If the enemy has no carried light (or isnt 
   * glowing!) then the monster has trouble finding the enemy. 
   * Remember we already checked to see if the monster can see in 
   * the dark. */

  else if (op->map && op->map->darkness > 0 && enemy && !enemy->invisible &&
           !stand_in_light (enemy) && (!QUERY_FLAG (op, FLAG_SEE_IN_DARK) || !QUERY_FLAG (op, FLAG_SEE_INVISIBLE)))
    {
      int dark = radius / (op->map->darkness);

      radius = (dark > MIN_MON_RADIUS) ? (dark + 1) : MIN_MON_RADIUS;
    }
  else if (!QUERY_FLAG (op, FLAG_SLEEP))
    return 1;

  /* enemy should already be on this map, so don't really need to check
   * for that.
   */
  if (rv->distance < (unsigned int) (QUERY_FLAG (enemy, FLAG_STEALTH) ? (radius / 2) + 1 : radius))
    {
      CLEAR_FLAG (op, FLAG_SLEEP);
      return 1;
    }
  return 0;
}

int
move_randomly (object *op)
{
  int i;

  /* Give up to 15 chances for a monster to move randomly */
  for (i = 0; i < 15; i++)
    {
      if (move_object (op, rndm (8) + 1))
        return 1;
    }
  return 0;
}

/*
 * Move-monster returns 1 if the object has been freed, otherwise 0.
 */
int
move_monster (object *op)
{
  int dir, diff, pre_att_dir;   /* elmex: pre_att_dir remembers the direction before attack movement */
  object *owner, *enemy, *part, *oph = op;
  rv_vector rv;

  /* Monsters not on maps don't do anything.  These monsters are things
   * Like royal guards in city dwellers inventories.
   */
  if (!op->map)
    return 0;

  /* for target facing, we copy this value here for fast access */
  if (oph->head)                /* force update the head - one arch one pic */
    oph = oph->head;

  if (QUERY_FLAG (op, FLAG_NO_ATTACK))  /* we never ever attack */
    enemy = op->enemy = NULL;
  else if ((enemy = find_enemy (op, &rv)))
    /* we have an enemy, just tell him we want him dead */
    enemy->attacked_by = op;  /* our ptr */

  /*  generate hp, if applicable */
  if (op->stats.Con > 0 && op->stats.hp < op->stats.maxhp)
    {

      /* last heal is in funny units.  Dividing by speed puts
       * the regeneration rate on a basis of time instead of
       * #moves the monster makes.  The scaling by 8 is
       * to capture 8th's of a hp fraction regens 
       *
       * Cast to sint32 before comparing to maxhp since otherwise an (sint16)
       * overflow might produce monsters with negative hp.
       */

      op->last_heal += (int) ((float) (8 * op->stats.Con) / FABS (op->speed));
      op->stats.hp = MIN ((sint32) op->stats.hp + op->last_heal / 32, op->stats.maxhp); /* causes Con/4 hp/tick */
      op->last_heal %= 32;

      /* So if the monster has gained enough HP that they are no longer afraid */
      if (QUERY_FLAG (op, FLAG_RUN_AWAY) && op->stats.hp >= (signed short) (((float) op->run_away / (float) 100) * (float) op->stats.maxhp))
        CLEAR_FLAG (op, FLAG_RUN_AWAY);

      if (op->stats.hp > op->stats.maxhp)
        op->stats.hp = op->stats.maxhp;
    }

  /* generate sp, if applicable */
  if (op->stats.Pow > 0 && op->stats.sp < op->stats.maxsp)
    {

      /*  last_sp is in funny units.  Dividing by speed puts
       * the regeneration rate on a basis of time instead of
       * #moves the monster makes.  The scaling by 8 is
       * to capture 8th's of a sp fraction regens 
       *
       * Cast to sint32 before comparing to maxhp since otherwise an (sint16)
       * overflow might produce monsters with negative sp.
       */

      op->last_sp += (int) ((float) (8 * op->stats.Pow) / FABS (op->speed));
      op->stats.sp = MIN (op->stats.sp + op->last_sp / 128, op->stats.maxsp);   /* causes Pow/16 sp/tick */
      op->last_sp %= 128;
    }

  /* this should probably get modified by many more values.
   * (eg, creatures resistance to fear, level, etc. )
   */
  if (QUERY_FLAG (op, FLAG_SCARED) && !(rndm (20)))
    {
      CLEAR_FLAG (op, FLAG_SCARED);     /* Time to regain some "guts"... */
    }

  if (INVOKE_OBJECT (MONSTER_MOVE, op, ARG_OBJECT (op->enemy)))
    return QUERY_FLAG (op, FLAG_FREED);

  if (QUERY_FLAG (op, FLAG_SLEEP) || QUERY_FLAG (op, FLAG_BLIND) ||
      ((op->map->darkness > 0) && !QUERY_FLAG (op, FLAG_SEE_IN_DARK) && !QUERY_FLAG (op, FLAG_SEE_INVISIBLE)))
    {
      if (!check_wakeup (op, enemy, &rv))
        return 0;
    }

  /* check if monster pops out of hidden spot */
  if (op->hide)
    do_hidden_move (op);

  if (op->pick_up)
    monster_check_pickup (op);

  if (op->will_apply)
    monster_apply_below (op);   /* Check for items to apply below */

  /* If we don't have an enemy, do special movement or the like */
  if (!enemy)
    {
      if (QUERY_FLAG (op, FLAG_ONLY_ATTACK))
        {
          op->destroy ();
          return 1;
        }

      /* Probably really a bug for a creature to have both
       * stand still and a movement type set.
       */
      if (!QUERY_FLAG (op, FLAG_STAND_STILL))
        {
          if (op->attack_movement & HI4)
            {
              switch (op->attack_movement & HI4)
                {
                    case (PETMOVE):
                      pet_move (op);
                      break;

                    case (CIRCLE1):
                      circ1_move (op);
                      break;

                    case (CIRCLE2):
                      circ2_move (op);
                      break;

                    case (PACEV):
                      pace_movev (op);
                      break;

                    case (PACEH):
                      pace_moveh (op);
                      break;

                    case (PACEV2):
                      pace2_movev (op);
                      break;

                    case (PACEH2):
                      pace2_moveh (op);
                      break;

                    case (RANDO):
                      rand_move (op);
                      break;

                    case (RANDO2):
                      move_randomly (op);
                      break;
                }
              return 0;
            }
          else if (QUERY_FLAG (op, FLAG_RANDOM_MOVE))
            (void) move_randomly (op);

        }                       /* stand still */
      return 0;
    }                           /* no enemy */

  /* We have an enemy.  Block immediately below is for pets */
  if ((op->attack_movement & HI4) == PETMOVE
      && (owner = op->owner) != NULL
      && !on_same_map (op, owner)
      && !owner->flag [FLAG_REMOVED])
    return follow_owner (op, owner);

  /* doppleganger code to change monster facing to that of the nearest
   * player.  Hmm.  The code is here, but no monster in the current
   * arch set uses it.
   */
  if ((op->race != NULL) && strcmp (op->race, "doppleganger") == 0)
    {
      op->face = enemy->face;
      op->name = enemy->name;
    }

  /* Calculate range information for closest body part - this
   * is used for the 'skill' code, which isn't that smart when
   * it comes to figuring it out - otherwise, giants throw boulders
   * into themselves.
   */
  get_rangevector (op, enemy, &rv, 0);

  /* Move the check for scared up here - if the monster was scared,
   * we were not doing any of the logic below, so might as well save
   * a few cpu cycles.
   */
  if (!QUERY_FLAG (op, FLAG_SCARED))
    {
      rv_vector rv1;

      /* now we test every part of an object .... this is a real ugly piece of code */
      for (part = op; part; part = part->more)
        {
          get_rangevector (part, enemy, &rv1, 0x1);
          dir = rv1.direction;

          /* hm, not sure about this part - in original was a scared flag here too
           * but that we test above... so can be old code here 
           */
          if (QUERY_FLAG (op, FLAG_RUN_AWAY))
            dir = absdir (dir + 4);

          if (QUERY_FLAG (op, FLAG_CONFUSED))
            dir = absdir (dir + rndm (3) + rndm (3) - 2);

          if (QUERY_FLAG (op, FLAG_CAST_SPELL) && !(rndm (3)))
            if (monster_cast_spell (op, part, enemy, dir, &rv1))
              return 0;

          if (QUERY_FLAG (op, FLAG_READY_SCROLL) && !(rndm (3)))
            if (monster_use_scroll (op, part, enemy, dir, &rv1))
              return 0;

          if (QUERY_FLAG (op, FLAG_READY_RANGE) && !(rndm (3)))
            if (monster_use_range (op, part, enemy, dir))
              return 0;

          if (QUERY_FLAG (op, FLAG_READY_SKILL) && !(rndm (3)))
            if (monster_use_skill (op, rv.part, enemy, rv.direction))
              return 0;

          if (QUERY_FLAG (op, FLAG_READY_BOW) && !(rndm (2)))
            if (monster_use_bow (op, part, enemy, dir))
              return 0;
        }                       /* for processing of all parts */
    }                           /* If not scared */


  part = rv.part;
  dir = rv.direction;

  if (QUERY_FLAG (op, FLAG_SCARED) || QUERY_FLAG (op, FLAG_RUN_AWAY))
    dir = absdir (dir + 4);

  if (QUERY_FLAG (op, FLAG_CONFUSED))
    dir = absdir (dir + rndm (3) + rndm (3) - 2);

  pre_att_dir = dir;            /* remember the original direction */

  if ((op->attack_movement & LO4) && !QUERY_FLAG (op, FLAG_SCARED))
    {
      switch (op->attack_movement & LO4)
        {
            case DISTATT:
              dir = dist_att (dir, op, enemy, part, &rv);
              break;

            case RUNATT:
              dir = run_att (dir, op, enemy, part, &rv);
              break;

            case HITRUN:
              dir = hitrun_att (dir, op, enemy);
              break;

            case WAITATT:
              dir = wait_att (dir, op, enemy, part, &rv);
              break;

            case RUSH:         /* default - monster normally moves towards player */
            case ALLRUN:
              break;

            case DISTHIT:
              dir = disthit_att (dir, op, enemy, part, &rv);
              break;

            case WAIT2:
              dir = wait_att2 (dir, op, enemy, part, &rv);
              break;

            default:
              LOG (llevDebug, "Illegal low mon-move: %d\n", op->attack_movement & LO4);
        }
    }

  if (!dir)
    return 0;

  if (!QUERY_FLAG (op, FLAG_STAND_STILL))
    {
      if (move_object (op, dir))        /* Can the monster move directly toward player? */
        {
          /* elmex: Turn our monster after it moved if it has DISTATT attack */
          if ((op->attack_movement & LO4) == DISTATT)
            op->direction = pre_att_dir;

          return 0;
        }

      if (QUERY_FLAG (op, FLAG_SCARED) || !can_hit (part, enemy, &rv) || QUERY_FLAG (op, FLAG_RUN_AWAY))
        {

          /* Try move around corners if !close */
          int maxdiff = (QUERY_FLAG (op, FLAG_ONLY_ATTACK) || RANDOM () & 1) ? 1 : 2;

          for (diff = 1; diff <= maxdiff; diff++)
            {
              /* try different detours */
              int m = 1 - (RANDOM () & 2);      /* Try left or right first? */

              if (move_object (op, absdir (dir + diff * m)) || move_object (op, absdir (dir - diff * m)))
                return 0;
            }
        }
    }                           /* if monster is not standing still */

  /* elmex: Turn our monster after it moved if it has DISTATT attack */
  if ((op->attack_movement & LO4) == DISTATT)
    op->direction = pre_att_dir;

  /*
   * Eneq(@csd.uu.se): Patch to make RUN_AWAY or SCARED monsters move a random
   * direction if they can't move away.
   */
  if (!QUERY_FLAG (op, FLAG_ONLY_ATTACK) && (QUERY_FLAG (op, FLAG_RUN_AWAY) || QUERY_FLAG (op, FLAG_SCARED)))
    if (move_randomly (op))
      return 0;

  /*
   * Try giving the monster a new enemy - the player that is closest
   * to it.  In this way, it won't just keep trying to get to a target
   * that is inaccessible.
   * This could be more clever - it should go through a list of several
   * enemies, as it is now, you could perhaps get situations where there
   * are two players flanking the monster at close distance, but which
   * the monster can't get to, and a third one at a far distance that
   * the monster could get to - as it is, the monster won't look at that
   * third one.
   */
  if (!QUERY_FLAG (op, FLAG_FRIENDLY) && enemy == op->enemy)
    {
      object *nearest_player = get_nearest_player (op);

      if (nearest_player && nearest_player != enemy && !can_hit (part, enemy, &rv))
        {
          op->enemy = NULL;
          enemy = nearest_player;
        }
    }

  if (!QUERY_FLAG (op, FLAG_SCARED) && can_hit (part, enemy, &rv))
    {
      /* The adjustement to wc that was here before looked totally bogus -
       * since wc can in fact get negative, that would mean by adding
       * the current wc, the creature gets better?  Instead, just
       * add a fixed amount - nasty creatures that are runny away should
       * still be pretty nasty.
       */
      if (QUERY_FLAG (op, FLAG_RUN_AWAY))
        {
          part->stats.wc += 10;
          (void) skill_attack (enemy, part, 0, NULL, NULL);
          part->stats.wc -= 10;
        }
      else
        (void) skill_attack (enemy, part, 0, NULL, NULL);
    }                           /* if monster is in attack range */

  if (QUERY_FLAG (part, FLAG_FREED))    /* Might be freed by ghost-attack or hit-back */
    return 1;

  if (QUERY_FLAG (op, FLAG_ONLY_ATTACK))
    {
      op->remove ();
      op->destroy ();
      return 1;
    }
  return 0;
}

int
can_hit (object *ob1, object *ob2, rv_vector * rv)
{
  object *more;
  rv_vector rv1;

  if (QUERY_FLAG (ob1, FLAG_CONFUSED) && !(rndm (3)))
    return 0;

  if (abs (rv->distance_x) < 2 && abs (rv->distance_y) < 2)
    return 1;

  /* check all the parts of ob2 - just because we can't get to
   * its head doesn't mean we don't want to pound its feet
   */
  for (more = ob2->more; more != NULL; more = more->more)
    {
      get_rangevector (ob1, more, &rv1, 0);
      if (abs (rv1.distance_x) < 2 && abs (rv1.distance_y) < 2)
        return 1;
    }
  return 0;

}

/* Returns 1 is monster should cast spell sp at an enemy
 * Returns 0 if the monster should not cast this spell.
 *
 * Note that this function does not check to see if the monster can
 * in fact cast the spell (sp dependencies and what not.)  That is because
 * this function is also sued to see if the monster should use spell items
 * (rod/horn/wand/scroll).
 * Note that there are certainly other offensive spells that could be
 * included, but I decided to leave out the spells that may kill more
 * monsters than players (eg, disease).
 *
 * This could be a lot smarter - if there are few monsters around,
 * then disease might not be as bad. Likewise, if the monster is damaged,
 * the right type of healing spell could be useful.
 */

static int
monster_should_cast_spell (object *monster, object *spell_ob)
{
  if (spell_ob->subtype == SP_BOLT || spell_ob->subtype == SP_BULLET ||
      spell_ob->subtype == SP_EXPLOSION || spell_ob->subtype == SP_CONE ||
      spell_ob->subtype == SP_BOMB || spell_ob->subtype == SP_SMITE ||
      spell_ob->subtype == SP_MAGIC_MISSILE || spell_ob->subtype == SP_SUMMON_GOLEM ||
      spell_ob->subtype == SP_MAGIC_WALL || spell_ob->subtype == SP_SUMMON_MONSTER ||
      spell_ob->subtype == SP_MOVING_BALL || spell_ob->subtype == SP_SWARM || spell_ob->subtype == SP_INVISIBLE)

    return 1;

  return 0;
}


#define MAX_KNOWN_SPELLS 20

/* Returns a randomly selected spell.    This logic is still
 * less than ideal.  This code also only seems to deal with
 * wizard spells, as the check is against sp, and not grace.
 * can mosnters know cleric spells?
 */
object *
monster_choose_random_spell (object *monster)
{
  object *altern[MAX_KNOWN_SPELLS];
  object *tmp;
  int i = 0;

  for (tmp = monster->inv; tmp != NULL; tmp = tmp->below)
    if (tmp->type == SPELLBOOK || tmp->type == SPELL)
      {
        /* Check and see if it's actually a useful spell.
         * If its a spellbook, the spell is actually the inventory item.
         * if it is a spell, then it is just the object itself.
         */
        if (monster_should_cast_spell (monster, (tmp->type == SPELLBOOK) ? tmp->inv : tmp))
          {
            altern[i++] = tmp;
            if (i == MAX_KNOWN_SPELLS)
              break;
          }
      }
  if (!i)
    return NULL;
  return altern[RANDOM () % i];
}

/* This checks to see if the monster should cast a spell/ability.
 * it returns true if the monster casts a spell, 0 if he doesn't.
 * head is the head of the monster.
 * part is the part of the monster we are checking against.
 * pl is the target.
 * dir is the direction to case.
 * rv is the vector which describes where the enemy is.
 */

int
monster_cast_spell (object *head, object *part, object *pl, int dir, rv_vector * rv)
{
  object *spell_item;
  object *owner;
  rv_vector rv1;

  /* If you want monsters to cast spells over friends, this spell should
   * be removed.  It probably should be in most cases, since monsters still
   * don't care about residual effects (ie, casting a cone which may have a 
   * clear path to the player, the side aspects of the code will still hit
   * other monsters)
   */
  if (!(dir = path_to_player (part, pl, 0)))
    return 0;

  if (QUERY_FLAG (head, FLAG_FRIENDLY) && (owner = head->owner) != NULL)
    {
      get_rangevector (head, owner, &rv1, 0x1);
      if (dirdiff (dir, rv1.direction) < 2)
        {
          return 0;             /* Might hit owner with spell */
        }
    }

  if (QUERY_FLAG (head, FLAG_CONFUSED))
    dir = absdir (dir + rndm (3) + rndm (3) - 2);

  /* If the monster hasn't already chosen a spell, choose one
   * I'm not sure if it really make sense to pre-select spells (events
   * could be different by the time the monster goes again).
   */
  if (head->spellitem == NULL)
    {
      if ((spell_item = monster_choose_random_spell (head)) == NULL)
        {
          LOG (llevMonster, "Turned off spells in %s\n", &head->name);
          CLEAR_FLAG (head, FLAG_CAST_SPELL);   /* Will be turned on when picking up book */
          return 0;
        }
      if (spell_item->type == SPELLBOOK)
        {
          if (!spell_item->inv)
            {
              LOG (llevError, "spellbook %s does not contain a spell?\n", &spell_item->name);
              return 0;
            }
          spell_item = spell_item->inv;
        }
    }
  else
    spell_item = head->spellitem;

  if (!spell_item)
    return 0;

  /* Best guess this is a defensive/healing spell */
  if (spell_item->range <= 1 || spell_item->stats.dam < 0)
    dir = 0;

  /* Monster doesn't have enough spell-points */
  if (head->stats.sp < SP_level_spellpoint_cost (head, spell_item, SPELL_MANA))
    return 0;

  if (head->stats.grace < SP_level_spellpoint_cost (head, spell_item, SPELL_GRACE))
    return 0;

  head->stats.sp -= SP_level_spellpoint_cost (head, spell_item, SPELL_MANA);
  head->stats.grace -= SP_level_spellpoint_cost (head, spell_item, SPELL_GRACE);

  /* set this to null, so next time monster will choose something different */
  head->spellitem = NULL;

  return cast_spell (part, part, dir, spell_item, NULL);
}


int
monster_use_scroll (object *head, object *part, object *pl, int dir, rv_vector * rv)
{
  object *scroll;
  object *owner;
  rv_vector rv1;

  /* If you want monsters to cast spells over friends, this spell should
   * be removed.  It probably should be in most cases, since monsters still
   * don't care about residual effects (ie, casting a cone which may have a 
   * clear path to the player, the side aspects of the code will still hit
   * other monsters)
   */
  if (!(dir = path_to_player (part, pl, 0)))
    return 0;

  if (QUERY_FLAG (head, FLAG_FRIENDLY) && (owner = head->owner) != NULL)
    {
      get_rangevector (head, owner, &rv1, 0x1);
      if (dirdiff (dir, rv1.direction) < 2)
        {
          return 0;             /* Might hit owner with spell */
        }
    }

  if (QUERY_FLAG (head, FLAG_CONFUSED))
    dir = absdir (dir + rndm (3) + rndm (3) - 2);

  for (scroll = head->inv; scroll; scroll = scroll->below)
    if (scroll->type == SCROLL && monster_should_cast_spell (head, scroll->inv))
      break;

  /* Used up all his scrolls, so nothing do to */
  if (!scroll)
    {
      CLEAR_FLAG (head, FLAG_READY_SCROLL);
      return 0;
    }

  /* Spell should be cast on caster (ie, heal, strength) */
  if (scroll->inv->range == 0)
    dir = 0;

  apply_scroll (part, scroll, dir);
  return 1;
}

/* monster_use_skill()-implemented 95-04-28 to allow monster skill use.
 * Note that monsters do not need the skills SK_MELEE_WEAPON and
 * SK_MISSILE_WEAPON to make those respective attacks, if we
 * required that we would drastically increase the memory
 * requirements of CF!! 
 *
 * The skills we are treating here are all but those. -b.t. 
 *
 * At the moment this is only useful for throwing, perhaps for
 * stealing. TODO: This should be more integrated in the game. -MT, 25.11.01
 */
int
monster_use_skill (object *head, object *part, object *pl, int dir)
{
  object *skill, *owner;

  if (!(dir = path_to_player (part, pl, 0)))
    return 0;

  if (QUERY_FLAG (head, FLAG_FRIENDLY) && (owner = head->owner) != NULL)
    {
      int dir2 = find_dir_2 (head->x - owner->x, head->y - owner->y);

      if (dirdiff (dir, dir2) < 1)
        return 0;               /* Might hit owner with skill -thrown rocks for example ? */
    }

  if (QUERY_FLAG (head, FLAG_CONFUSED))
    dir = absdir (dir + rndm (3) + rndm (3) - 2);

  /* skill selection - monster will use the next unused skill.
   * well...the following scenario will allow the monster to 
   * toggle between 2 skills. One day it would be nice to make
   * more skills available to monsters.
   */
  for (skill = head->inv; skill; skill = skill->below)
    if (skill->type == SKILL && skill != head->chosen_skill)
      {
        head->chosen_skill = skill;
        break;
      }

  if (!skill && !head->chosen_skill)
    {
      LOG (llevDebug, "Error: Monster %s (%d) has FLAG_READY_SKILL without skill.\n", &head->name, head->count);
      CLEAR_FLAG (head, FLAG_READY_SKILL);
      return 0;
    }

  /* use skill */
  return do_skill (head, part, head->chosen_skill, dir, NULL);
}

/* Monster will use a ranged spell attack. */
int
monster_use_range (object *head, object *part, object *pl, int dir)
{
  object *wand, *owner;
  int at_least_one = 0;

  if (!(dir = path_to_player (part, pl, 0)))
    return 0;

  if (QUERY_FLAG (head, FLAG_FRIENDLY) && (owner = head->owner) != NULL)
    {
      int dir2 = find_dir_2 (head->x - owner->x, head->y - owner->y);

      if (dirdiff (dir, dir2) < 2)
        return 0;               /* Might hit owner with spell */
    }

  if (QUERY_FLAG (head, FLAG_CONFUSED))
    dir = absdir (dir + rndm (3) + rndm (3) - 2);

  for (wand = head->inv; wand; wand = wand->below)
    {
      if (wand->type == WAND)
        {
          /* Found a wand, let's see if it has charges left */
          at_least_one = 1;
          if (wand->stats.food <= 0)
            continue;

          cast_spell (head, wand, dir, wand->inv, NULL);

          if (!(--wand->stats.food))
            {
              if (wand->arch)
                {
                  CLEAR_FLAG (wand, FLAG_ANIMATE);
                  wand->face = wand->arch->face;
                  wand->set_speed (0);
                }
            }
          /* Success */
          return 1;
        }
      else if (wand->type == ROD || wand->type == HORN)
        {
          /* Found rod/horn, let's use it if possible */
          at_least_one = 1;
          if (wand->stats.hp < MAX (wand->inv->stats.sp, wand->inv->stats.grace))
            continue;

          /* drain charge before casting spell - can be a case where the
           * spell destroys the monster, and rod, so if done after, results
           * in crash.
           */
          drain_rod_charge (wand);
          cast_spell (head, wand, dir, wand->inv, NULL);

          /* Success */
          return 1;
        }
    }

  if (at_least_one)
    return 0;

  LOG (llevError, "Error: Monster %s (%d) HAS_READY_RANGE() without wand/horn/rod.\n", &head->name, head->count);
  CLEAR_FLAG (head, FLAG_READY_RANGE);
  return 0;
}

int
monster_use_bow (object *head, object *part, object *pl, int dir)
{
  object *owner;

  if (!(dir = path_to_player (part, pl, 0)))
    return 0;

  if (QUERY_FLAG (head, FLAG_CONFUSED))
    dir = absdir (dir + rndm (3) + rndm (3) - 2);

  if (QUERY_FLAG (head, FLAG_FRIENDLY) && (owner = head->owner) != NULL)
    {
      int dir2 = find_dir_2 (head->x - owner->x, head->y - owner->y);

      if (dirdiff (dir, dir2) < 1)
        return 0;               /* Might hit owner with arrow */
    }

  /* in server/player.c */
  return fire_bow (head, part, NULL, dir, 0, part->x, part->y);

}

/* Checks if putting on 'item' will make 'who' do more
 * damage. This is a very simplistic check - also checking things
 * like speed and ac are also relevant.
 *
 * return true if item is a better object.
 */
int
check_good_weapon (object *who, object *item)
{
  object *other_weap;
  int val = 0, i;

  for (other_weap = who->inv; other_weap; other_weap = other_weap->below)
    if (other_weap->type == item->type && QUERY_FLAG (other_weap, FLAG_APPLIED))
      break;

  if (!other_weap)       /* No other weapons */
    return 1;

  /* Rather than go through and apply the new one, and see if it is
   * better, just do some simple checks
   * Put some multipliers for things that hvae several effects,
   * eg, magic affects both damage and wc, so it has more weight
   */

  val = item->stats.dam - other_weap->stats.dam;
  val += (item->magic - other_weap->magic) * 3;
  /* Monsters don't really get benefits from things like regen rates
   * from items.  But the bonus for their stats are very important.
   */
  for (i = 0; i < NUM_STATS; i++)
    val += item->stats.stat (i) - other_weap->stats.stat (i) * 2;

  if (val > 0)
    return 1;
  else
    return 0;
}

int
check_good_armour (object *who, object *item)
{
  object *other_armour;
  int val = 0, i;

  for (other_armour = who->inv; other_armour; other_armour = other_armour->below)
    if (other_armour->type == item->type && QUERY_FLAG (other_armour, FLAG_APPLIED))
      break;

  if (other_armour == NULL)     /* No other armour, use the new */
    return 1;

  /* Like above function , see which is better */
  val = item->stats.ac - other_armour->stats.ac;
  val = (item->resist[ATNR_PHYSICAL] - other_armour->resist[ATNR_PHYSICAL]) / 5;
  val += (item->magic - other_armour->magic) * 3;

  /* for the other protections, do weigh them very much in the equation -
   * it is the armor protection which is most important, because there is
   * no good way to know what the player may attack the monster with. 
   * So if the new item has better protection than the old, give that higher
   * value.  If the reverse, then decrease the value of this item some.
   */
  for (i = 1; i < NROFATTACKS; i++)
    {
      if (item->resist[i] > other_armour->resist[i])
        val++;
      else if (item->resist[i] < other_armour->resist[i])
        val--;
    }

  /* Very few armours have stats, so not much need to worry about those. */

  if (val > 0)
    return 1;
  else
    return 0;
}

/*
 * monster_check_pickup(): checks for items that monster can pick up.
 *
 * Vick's (vick@bern.docs.uu.se) fix 921030 for the sweeper blob.
 * Each time the blob passes over some treasure, it will
 * grab it a.s.a.p.
 *
 * Eneq(@csd.uu.se): This can now be defined in the archetypes, added code
 * to handle this.
 *
 * This function was seen be continueing looping at one point (tmp->below
 * became a recursive loop.  It may be better to call monster_check_apply
 * after we pick everything up, since that function may call others which
 * affect stacking on this space.
 */
void
monster_check_pickup (object *monster)
{
  object *tmp, *next;

  for (tmp = monster->below; tmp != NULL; tmp = next)
    {
      next = tmp->below;
      if (monster_can_pick (monster, tmp))
        {
          tmp->remove ();
          tmp = insert_ob_in_ob (tmp, monster);
          (void) monster_check_apply (monster, tmp);
        }
      /* We could try to re-establish the cycling, of the space, but probably
       * not a big deal to just bail out.
       */
      if (next && next->destroyed ())
        return;
    }
}

/*
 * monster_can_pick(): If the monster is interested in picking up
 * the item, then return 0.  Otherwise 0.
 * Instead of pick_up, flags for "greed", etc, should be used.
 * I've already utilized flags for bows, wands, rings, etc, etc. -Frank.
 */
int
monster_can_pick (object *monster, object *item)
{
  int flag = 0;
  int i;

  if (!can_pick (monster, item))
    return 0;

  if (QUERY_FLAG (item, FLAG_UNPAID))
    return 0;

  if (monster->pick_up & 64)    /* All */
    flag = 1;

  else
    switch (item->type)
      {
          case MONEY:
          case GEM:
            flag = monster->pick_up & 2;
            break;

          case FOOD:
            flag = monster->pick_up & 4;
            break;

          case WEAPON:
            flag = (monster->pick_up & 8) || QUERY_FLAG (monster, FLAG_USE_WEAPON);
            break;

          case ARMOUR:
          case SHIELD:
          case HELMET:
          case BOOTS:
          case GLOVES:
          case GIRDLE:
            flag = (monster->pick_up & 16) || QUERY_FLAG (monster, FLAG_USE_ARMOUR);
            break;

          case SKILL:
            flag = QUERY_FLAG (monster, FLAG_CAN_USE_SKILL);
            break;

          case RING:
            flag = QUERY_FLAG (monster, FLAG_USE_RING);
            break;

          case WAND:
          case HORN:
          case ROD:
            flag = QUERY_FLAG (monster, FLAG_USE_RANGE);
            break;

          case SPELLBOOK:
            flag = monster->arch && QUERY_FLAG (monster->arch, FLAG_CAST_SPELL);
            break;

          case SCROLL:
            flag = QUERY_FLAG (monster, FLAG_USE_SCROLL);
            break;

          case BOW:
          case ARROW:
            flag = QUERY_FLAG (monster, FLAG_USE_BOW);
            break;
      }

  /* Simplistic check - if the monster has a location to equip it, he will
   * pick it up.  Note that this doesn't handle cases where an item may
   * use several locations.
   */
  for (i = 0; i < NUM_BODY_LOCATIONS; i++)
    {
      if (monster->slot[i].info && item->slot[i].info)
        {
          flag = 1;
          break;
        }
    }

  if (((!(monster->pick_up & 32)) && flag) || ((monster->pick_up & 32) && (!flag)))
    return 1;
  return 0;
}

/*
 * monster_apply_below():
 * Vick's (vick@bern.docs.uu.se) @921107 -> If a monster who's
 * eager to apply things, encounters something apply-able,
 * then make him apply it
 */
void
monster_apply_below (object *monster)
{
  object *tmp, *next;

  for (tmp = monster->below; tmp != NULL; tmp = next)
    {
      next = tmp->below;
      switch (tmp->type)
        {
            case CF_HANDLE:
            case TRIGGER:
              if (monster->will_apply & 1)
                manual_apply (monster, tmp, 0);
              break;

            case TREASURE:
              if (monster->will_apply & 2)
                manual_apply (monster, tmp, 0);
              break;

        }
      if (QUERY_FLAG (tmp, FLAG_IS_FLOOR))
        break;
    }
}

/*
 * monster_check_apply() is meant to be called after an item is
 * inserted in a monster.
 * If an item becomes outdated (monster found a better item),
 * a pointer to that object is returned, so it can be dropped.
 * (so that other monsters can pick it up and use it)
 * Note that as things are now, monsters never drop something -
 * they can pick up all that they can use.
 */
/* Sept 96, fixed this so skills will be readied -b.t.*/
void
monster_check_apply (object *mon, object *item)
{
  int flag = 0;

  if (item->type == SPELLBOOK && mon->arch && (QUERY_FLAG (mon->arch, FLAG_CAST_SPELL)))
    {
      SET_FLAG (mon, FLAG_CAST_SPELL);
      return;
    }

  /* If for some reason, this item is already applied, no more work to do */
  if (QUERY_FLAG (item, FLAG_APPLIED))
    return;

  /* Might be better not to do this - if the monster can fire a bow,
   * it is possible in his wanderings, he will find one to use.  In
   * which case, it would be nice to have ammo for it.
   */
  if (QUERY_FLAG (mon, FLAG_USE_BOW) && item->type == ARROW)
    {
      /* Check for the right kind of bow */
      object *bow;

      for (bow = mon->inv; bow; bow = bow->below)
        if (bow->type == BOW && bow->race == item->race)
          {
            SET_FLAG (mon, FLAG_READY_BOW);
            LOG (llevMonster, "Found correct bow for arrows.\n");
            return;             /* nothing more to do for arrows */
          }
    }

  if (item->type == TREASURE && mon->will_apply & WILL_APPLY_TREASURE)
    flag = 1;
  /* Eating food gets hp back */
  else if (item->type == FOOD && mon->will_apply & WILL_APPLY_FOOD)
    flag = 1;
  else if (item->type == SCROLL && QUERY_FLAG (mon, FLAG_USE_SCROLL))
    {
      if (!item->inv)
        LOG (llevDebug, "Monster %d having scroll %d with empty inventory!", mon->count, item->count);
      else if (monster_should_cast_spell (mon, item->inv))
        SET_FLAG (mon, FLAG_READY_SCROLL);
      /* Don't use it right now */
      return;
    }
  else if (item->type == WEAPON)
    flag = check_good_weapon (mon, item);
  else if (item->is_armor ())
    flag = check_good_armour (mon, item);
  /* Should do something more, like make sure this is a better item */
  else if (item->type == RING)
    flag = 1;
  else if (item->type == WAND || item->type == ROD || item->type == HORN)
    {
      /* We never really 'ready' the wand/rod/horn, because that would mean the
       * weapon would get undone.
       */
      if (!(can_apply_object (mon, item) & CAN_APPLY_NOT_MASK))
        {
          SET_FLAG (mon, FLAG_READY_RANGE);
          SET_FLAG (item, FLAG_APPLIED);
        }
      return;
    }
  else if (item->type == BOW)
    {
      /* We never really 'ready' the bow, because that would mean the
       * weapon would get undone.
       */
      if (!(can_apply_object (mon, item) & CAN_APPLY_NOT_MASK))
        SET_FLAG (mon, FLAG_READY_BOW);
      return;
    }
  else if (item->type == SKILL)
    {
      /*
       * skills are specials: monsters must have the 'FLAG_READY_SKILL' flag set,
       * else they can't use the skill...
       * Skills also don't need to get applied, so return now.
       */
      SET_FLAG (mon, FLAG_READY_SKILL);
      return;
    }

  /* if we don't match one of the above types, return now.
   * can_apply_object will say that we can apply things like flesh, 
   * bolts, and whatever else, because it only checks against the
   * body_info locations.
   */
  if (!flag)
    return;

  /* Check to see if the monster can use this item.  If not, no need
   * to do further processing.  Note that can_apply_object already checks
   * for the CAN_USE flags.
   */
  if (can_apply_object (mon, item) & CAN_APPLY_NOT_MASK)
    return;

  /* should only be applying this item, not unapplying it.
   * also, ignore status of curse so they can take off old armour.
   * monsters have some advantages after all.
   */
  manual_apply (mon, item, AP_APPLY | AP_IGNORE_CURSE);
}

void
npc_call_help (object *op)
{
  int x, y, mflags;
  object *npc;
  sint16 sx, sy;
  maptile *m;

  for (x = -3; x < 4; x++)
    for (y = -3; y < 4; y++)
      {
        m = op->map;
        sx = op->x + x;
        sy = op->y + y;
        mflags = get_map_flags (m, &m, sx, sy, &sx, &sy);
        /* If nothing alive on this space, no need to search the space. */
        if ((mflags & P_OUT_OF_MAP) || !(mflags & P_IS_ALIVE))
          continue;

        for (npc = GET_MAP_OB (m, sx, sy); npc != NULL; npc = npc->above)
          if (QUERY_FLAG (npc, FLAG_ALIVE) && QUERY_FLAG (npc, FLAG_UNAGGRESSIVE))
            npc->enemy = op->enemy;
      }
}

int
dist_att (int dir, object *ob, object *enemy, object *part, rv_vector * rv)
{
  if (can_hit (part, enemy, rv))
    return dir;
  if (rv->distance < 10)
    return absdir (dir + 4);
  else if (rv->distance > 18)
    return dir;

  return 0;
}

int
run_att (int dir, object *ob, object *enemy, object *part, rv_vector * rv)
{
  if ((can_hit (part, enemy, rv) && ob->move_status < 20) || ob->move_status < 20)
    {
      ob->move_status++;
      return (dir);
    }
  else if (ob->move_status > 20)
    ob->move_status = 0;

  return absdir (dir + 4);
}

int
hitrun_att (int dir, object *ob, object *enemy)
{
  if (ob->move_status++ < 25)
    return dir;
  else if (ob->move_status < 50)
    return absdir (dir + 4);
  else
    ob->move_status = 0;

  return absdir (dir + 4);
}

int
wait_att (int dir, object *ob, object *enemy, object *part, rv_vector * rv)
{

  int inrange = can_hit (part, enemy, rv);

  if (ob->move_status || inrange)
    ob->move_status++;

  if (ob->move_status == 0)
    return 0;
  else if (ob->move_status < 10)
    return dir;
  else if (ob->move_status < 15)
    return absdir (dir + 4);

  ob->move_status = 0;
  return 0;
}

int
disthit_att (int dir, object *ob, object *enemy, object *part, rv_vector * rv)
{

  /* The logic below here looked plain wrong before.  Basically, what should
   * happen is that if the creatures hp percentage falls below run_away,
   * the creature should run away (dir+4)
   * I think its wrong for a creature to have a zero maxhp value, but
   * at least one map has this set, and whatever the map contains, the
   * server should try to be resilant enough to avoid the problem
   */
  if (ob->stats.maxhp && (ob->stats.hp * 100) / ob->stats.maxhp < ob->run_away)
    return absdir (dir + 4);

  return dist_att (dir, ob, enemy, part, rv);
}

int
wait_att2 (int dir, object *ob, object *enemy, object *part, rv_vector * rv)
{
  if (rv->distance < 9)
    return absdir (dir + 4);

  return 0;
}

void
circ1_move (object *ob)
{
  static int circle[12] = { 3, 3, 4, 5, 5, 6, 7, 7, 8, 1, 1, 2 };

  if (++ob->move_status > 11)
    ob->move_status = 0;

  if (!(move_object (ob, circle[ob->move_status])))
    move_object (ob, rndm (8) + 1);
}

void
circ2_move (object *ob)
{
  static int circle[20] = { 3, 3, 3, 4, 4, 5, 5, 5, 6, 6, 7, 7, 7, 8, 8, 1, 1, 1, 2, 2 };

  if (++ob->move_status > 19)
    ob->move_status = 0;

  if (!(move_object (ob, circle[ob->move_status])))
    move_object (ob, rndm (8) + 1);
}

void
pace_movev (object *ob)
{
  if (ob->move_status++ > 6)
    ob->move_status = 0;

  if (ob->move_status < 4)
    move_object (ob, 5);
  else
    move_object (ob, 1);
}

void
pace_moveh (object *ob)
{
  if (ob->move_status++ > 6)
    ob->move_status = 0;

  if (ob->move_status < 4)
    move_object (ob, 3);
  else
    move_object (ob, 7);
}

void
pace2_movev (object *ob)
{
  if (ob->move_status++ > 16)
    ob->move_status = 0;

  if (ob->move_status < 6)
    move_object (ob, 5);
  else if (ob->move_status < 8)
    return;
  else if (ob->move_status < 13)
    move_object (ob, 1);
  else
    return;
}

void
pace2_moveh (object *ob)
{
  if (ob->move_status++ > 16)
    ob->move_status = 0;

  if (ob->move_status < 6)
    move_object (ob, 3);
  else if (ob->move_status < 8)
    return;
  else if (ob->move_status < 13)
    move_object (ob, 7);
  else
    return;
}

void
rand_move (object *ob)
{
  int i;

  if (ob->move_status < 1 || ob->move_status > 8 || !(move_object (ob, ob->move_status || !(rndm (9)))))
    for (i = 0; i < 5; i++)
      if (move_object (ob, ob->move_status = rndm (8) + 1))
        return;
}

void
check_earthwalls (object *op, maptile *m, int x, int y)
{
  object *tmp;

  for (tmp = GET_MAP_OB (m, x, y); tmp != NULL; tmp = tmp->above)
    {
      if (tmp->type == EARTHWALL)
        {
          hit_player (tmp, op->stats.dam, op, AT_PHYSICAL, 1);
          return;
        }
    }
}

void
check_doors (object *op, maptile *m, int x, int y)
{
  object *tmp;

  for (tmp = GET_MAP_OB (m, x, y); tmp != NULL; tmp = tmp->above)
    {
      if (tmp->type == DOOR)
        {
          hit_player (tmp, 1000, op, AT_PHYSICAL, 1);
          return;
        }
    }
}

/* find_mon_throw_ob() - modeled on find_throw_ob
 * This is probably overly simplistic as it is now - We want
 * monsters to throw things like chairs and other pieces of
 * furniture, even if they are not good throwable objects.
 * Probably better to have the monster throw a throwable object
 * first, then throw any non equipped weapon.
 */
object *
find_mon_throw_ob (object *op)
{
  object *tmp = NULL;

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

  /* New throw code: look through the inventory. Grap the first legal is_thrown
   * marked item and throw it to the enemy.
   */
  for (tmp = op->inv; tmp; tmp = tmp->below)
    {
      /* Can't throw invisible objects or items that are applied */
      if (tmp->invisible || QUERY_FLAG (tmp, FLAG_APPLIED))
        continue;

      if (QUERY_FLAG (tmp, FLAG_IS_THROWN))
        break;

    }

#ifdef DEBUG_THROW
  LOG (llevDebug, "%s chooses to throw: %s (%d)\n", op->name, !(tmp) ? "(nothing)" : query_name (tmp), tmp ? tmp->count : -1);
#endif

  return tmp;
}

/* determine if we can 'detect' the enemy. Check for walls blocking the
 * los. Also, just because its hidden/invisible, we may be sensitive/smart 
 * enough (based on Wis & Int) to figure out where the enemy is. -b.t. 
 * modified by MSW to use the get_rangevector so that map tiling works
 * properly.  I also so odd code in place that checked for x distance
 * OR y distance being within some range - that seemed wrong - both should
 * be within the valid range. MSW 2001-08-05
 * Returns 0 if enemy can not be detected, 1 if it is detected
 */

int
can_detect_enemy (object *op, object *enemy, rv_vector * rv)
{
  int radius = MIN_MON_RADIUS, hide_discovery;

  /* null detection for any of these condtions always */
  if (!op || !enemy || !op->map || !enemy->map)
    return 0;

  /* If the monster (op) has no way to get to the enemy, do nothing */
  if (!on_same_map (op, enemy))
    return 0;

  get_rangevector (op, enemy, rv, 0);

  /* Monsters always ignore the DM */
  if ((op->type != PLAYER) && QUERY_FLAG (enemy, FLAG_WIZ))
    return 0;

  /* simple check.  Should probably put some range checks in here. */
  if (can_see_enemy (op, enemy))
    return 1;

  /* The rest of this is for monsters. Players are on their own for
   * finding enemies!
   */
  if (op->type == PLAYER)
    return 0;

  /* Quality invisible? Bah, we wont see them w/o SEE_INVISIBLE
   * flag (which was already checked) in can_see_enmy (). Lets get out of here 
   */
  if (enemy->invisible && (!enemy->contr || (!enemy->contr->tmp_invis && !enemy->contr->hidden)))
    return 0;

  /* use this for invis also */
  hide_discovery = op->stats.Int / 5;

  /* Determine Detection radii */
  if (!enemy->hide)             /* to detect non-hidden (eg dark/invis enemy) */
    radius = (op->stats.Wis / 5) + 1 > MIN_MON_RADIUS ? (op->stats.Wis / 5) + 1 : MIN_MON_RADIUS;
  else
    {                           /* a level/INT/Dex adjustment for hiding */
      object *sk_hide;
      int bonus = (op->level / 2) + (op->stats.Int / 5);

      if (enemy->type == PLAYER)
        {
          if ((sk_hide = find_skill_by_number (enemy, SK_HIDING)))
            bonus -= sk_hide->level;
          else
            {
              LOG (llevError, "can_detect_enemy() got hidden player w/o hiding skill!\n");
              make_visible (enemy);
              radius = radius < MIN_MON_RADIUS ? MIN_MON_RADIUS : radius;
            }
        }
      else                      /* enemy is not a player */
        bonus -= enemy->level;

      radius += bonus / 5;
      hide_discovery += bonus * 5;
    }                           /* else creature has modifiers for hiding */

  /* Radii stealth adjustment. Only if you are stealthy 
   * will you be able to sneak up closer to creatures */
  if (QUERY_FLAG (enemy, FLAG_STEALTH))
    radius = radius / 2, hide_discovery = hide_discovery / 3;

  /* Radii adjustment for enemy standing in the dark */
  if (op->map->darkness > 0 && !stand_in_light (enemy))
    {
      /* on dark maps body heat can help indicate location with infravision
       * undead don't have body heat, so no benefit detecting them.
       */
      if (QUERY_FLAG (op, FLAG_SEE_IN_DARK) && !is_true_undead (enemy))
        radius += op->map->darkness / 2;
      else
        radius -= op->map->darkness / 2;

      /* op next to a monster (and not in complete darkness) 
       * the monster should have a chance to see you. 
       */
      if (radius < MIN_MON_RADIUS && op->map->darkness < 5 && rv->distance <= 1)
        radius = MIN_MON_RADIUS;
    }                           /* if on dark map */

  /* Lets not worry about monsters that have incredible detection
   * radii, we only need to worry here about things the player can
   * (potentially) see.  This is 13, as that is the maximum size the player
   * may have for their map - in that way, creatures at the edge will
   * do something.  Note that the distance field in the
   * vector is real distance, so in theory this should be 18 to
   * find that.
   */
  if (radius > 13)
    radius = 13;

  /* Enemy in range! Now test for detection */
  if ((int) rv->distance <= radius)
    {
      /* ah, we are within range, detected? take cases */
      if (!enemy->invisible)    /* enemy in dark squares... are seen! */
        return 1;

      /* hidden or low-quality invisible */
      if (enemy->hide && (rv->distance <= 1) && (rndm (100) <= hide_discovery))
        {
          make_visible (enemy);
          /* inform players of new status */
          if (enemy->type == PLAYER && player_can_view (enemy, op))
            new_draw_info_format (NDI_UNIQUE, 0, enemy, "You are discovered by %s!", &op->name);
          return 1;             /* detected enemy */
        }
      else if (enemy->invisible)
        {
          /* Change this around - instead of negating the invisible, just
           * return true so that the mosnter that managed to detect you can
           * do something to you.  Decreasing the duration of invisible
           * doesn't make a lot of sense IMO, as a bunch of stupid creatures
           * can then basically negate the spell.  The spell isn't negated -
           * they just know where you are!
           */
          if ((rndm (50)) <= hide_discovery)
            {
              if (enemy->type == PLAYER)
                {
                  new_draw_info_format (NDI_UNIQUE, 0, enemy, "You see %s noticing your position.", query_name (op));
                }
              return 1;
            }
        }
    }                           /* within range */

  /* Wasn't detected above, so still hidden */
  return 0;
}

/* determine if op stands in a lighted square. This is not a very
 * intellegent algorithm. For one thing, we ignore los here, SO it 
 * is possible for a bright light to illuminate a player on the 
 * other side of a wall (!). 
 */
int
stand_in_light (object *op)
{
  sint16 nx, ny;
  maptile *m;

  if (!op)
    return 0;

  if (op->glow_radius > 0)
    return 1;

  if (op->map)
    {
      int x, y, x1, y1;

      /* Check the spaces with the max light radius to see if any of them
       * have lights, and if any of them light the player enough, then return 1.
       */
      for (x = op->x - MAX_LIGHT_RADII; x <= op->x + MAX_LIGHT_RADII; x++)
        {
          for (y = op->y - MAX_LIGHT_RADII; y <= op->y + MAX_LIGHT_RADII; y++)
            {
              m = op->map;
              nx = x;
              ny = y;

              if (get_map_flags (m, &m, nx, ny, &nx, &ny) & P_OUT_OF_MAP)
                continue;

              x1 = abs (x - op->x) * abs (x - op->x);
              y1 = abs (y - op->y) * abs (y - op->y);
              if (isqrt (x1 + y1) < GET_MAP_LIGHT (m, nx, ny))
                return 1;
            }
        }
    }

  return 0;
}

/* assuming no walls/barriers, lets check to see if its *possible* 
 * to see an enemy. Note, "detection" is different from "seeing".
 * See can_detect_enemy() for more details. -b.t.
 * return 0 if can't be seen, 1 if can be
 */
int
can_see_enemy (object *op, object *enemy)
{
  object *looker = op->head ? op->head : op;

  /* safety */
  if (!looker || !enemy || !QUERY_FLAG (looker, FLAG_ALIVE))
    return 0;

  /* we dont give a full treatment of xrays here (shorter range than normal,
   * see through walls). Should we change the code elsewhere to make you 
   * blind even if you can xray? 
   */
  if (QUERY_FLAG (looker, FLAG_BLIND) && !QUERY_FLAG (looker, FLAG_XRAYS))
    return 0;

  /* checking for invisible things */
  if (enemy->invisible)
    {
      /* HIDDEN ENEMY. by definition, you can't see hidden stuff! 
       * However,if you carry any source of light, then the hidden
       * creature is seeable (and stupid) */

      if (has_carried_lights (enemy))
        {
          if (enemy->hide)
            {
              make_visible (enemy);
              new_draw_info (NDI_UNIQUE, 0, enemy, "Your light reveals your hiding spot!");
            }
          return 1;
        }
      else if (enemy->hide)
        return 0;

      /* Invisible enemy.  Break apart the check for invis undead/invis looker
       * into more simple checks - the QUERY_FLAG doesn't return 1/0 values,
       * and making it a conditional makes the code pretty ugly.
       */
      if (!QUERY_FLAG (looker, FLAG_SEE_INVISIBLE))
        {
          if (makes_invisible_to (enemy, looker))
            return 0;
        }
    }
  else if (looker->type == PLAYER)      /* for players, a (possible) shortcut */
    if (player_can_view (looker, enemy))
      return 1;

  /* ENEMY IN DARK MAP. Without infravision, the enemy is not seen 
   * unless they carry a light or stand in light. Darkness doesnt
   * inhibit the undead per se (but we should give their archs
   * CAN_SEE_IN_DARK, this is just a safety  
   * we care about the enemy maps status, not the looker.
   * only relevant for tiled maps, but it is possible that the
   * enemy is on a bright map and the looker on a dark - in that
   * case, the looker can still see the enemy
   */
  if (enemy->map->darkness > 0 && !stand_in_light (enemy)
      && (!QUERY_FLAG (looker, FLAG_SEE_IN_DARK) || !is_true_undead (looker) || !QUERY_FLAG (looker, FLAG_XRAYS)))
    return 0;

  return 1;
}
Revision:	1.36
Committed:	Sun Jul 1 05:00:20 2007 UTC (16 years, 11 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.35:	+10 -11 lines
Log Message:	- upgrade crossfire trt to the GPL version 3 (hopefully correctly). - add a single file covered by the GNU Affero General Public License (which is not yet released, so I used the current draft, which is legally a bit wavy, but its likely better than nothing as it expresses direct intent by the authors, and we can upgrade as soon as it has been released). * this should ensure availability of source code for the server at least and hopefully also archetypes and maps even when modified versions are not being distributed, in accordance of section 13 of the agplv3.