server/server/disease.C

/*
 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
 * 
 * Copyright (©) 2005,2006,2007,2008,2009 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
 * Copyright (©) 2002,2007 Mark Wedel & Crossfire Development Team
 * Copyright (©) 1992,2007 Frank Tore Johansen
 * 
 * Deliantra is free software: you can redistribute it and/or modify it under
 * the terms of the Affero 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 Affero GNU General Public License
 * and 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 <support@deliantra.net>
 */

/* This file contains all the code implementing diseases,
 * except for odds and ends in attack.c and in 
 * living.c
 */

/*

For DISEASES:
Stat            Property        Definition

attacktype      Attack effects  Attacktype of the disease. usu. AT_GODPOWER.
other_arch      Creation        object created and dropped when symptom moved.
title           Message         When the "disease" "infects" something, it will
                                print "title victim!!!" to the player who owns
                                the "disease".
wc+             Infectiousness  How well the plague spreads person-to-person
magic+          Range           range of infection 
Stats*          Disability      What stats are reduced by the disease (str con...)
maxhp+          Persistence     How long the disease can last OUTSIDE the host. 
value           TimeLeft        Counter for persistence 
dam^            Damage          How much damage it does (%?). 
maxgrace+       Duration        How long before the disease is naturally cured. 
food            DurCount        Counter for Duration 

speed           Speed           How often the disease moves. 
last_sp^        Lethargy        Percentage of max speed. 10 = 10% speed. 

maxsp^          Mana deplete    Saps mana. 
ac^             Progressiveness How the diseases increases in severity.
last_eat*^      Deplete food    saps food if negative 
last_heal       GrantImmunity   If nonzero, disease does NOT grant immunity
                                when it runs out                              

exp             experience      experience awarded when plague cured 
hp*^            ReduceRegen     reduces regeneration of disease-bearer 
sp*^            ReduceSpRegen   reduces spellpoint regeneration 

name            Name            Name of the plague 
msg             message         What the plague says when it strikes.
race            those affected  species/race the plague strikes (* = everything) 
level           Plague Level    General description of the plague's deadliness
armour          Attenuation     reduction in wc per generation of disease.
                                This builds in a self-limiting factor.


Explanations:
* means this # should be negative to cause adverse effect.
+ means that this effect is modulated in spells by ldur
^ means that this effect is modulated in spells by ldam

attacktype is the attacktype used by the disease to smite "dam" damage with.

wc/127 is the chance of someone in range catching it.

magic is the range at which infection may occur.  If negative, the range is
NOT level dependent.

Stats are stat modifications.  These should typically be negative.

maxhp is how long the disease will persist if the host dies and "drops" it,
      in "disease moves", i.e., moves of the disease.  If negative, permanent.
      

value is the counter for maxhp, it starts at maxhp and drops...

dam     if positive, it is straight damage.  if negative, a %-age.

maxgrace  how long in "disease moves" the disease lasts in the host, if negative,
          permanent until cured.

food    if negative, disease is permanent.  otherwise, decreases at <speed>,
        disease goes away at food=0, set to "maxgrace" on infection.

speed is the speed of the disease, how fast "disease moves" occur.

last_sp is the lethargy imposed on the player by the disease.  A lethargy
       of "1" reduces the players speed to 1% of its normal value.

maxsp how much mana is sapped per "disease move".  if negative, a %-age is
     taken.

ac  every "disease move" the severity of the symptoms are increased by
    ac/100.  (severity = 1 + (accumlated_progression)/100)

last_eat  increases food usage if negative.


For SYMPTOMS:

Stats            modify stats
hp               modify regen
value            progression counter (multiplier = value/100)
food             modify food use (from last_eat in DISEASE)
maxsp            suck mana ( as noted for DISEASE)
last_sp          Lethargy
msg              What to say
speed            speed of movement, from DISEASE


*/


#include <global.h>
#include <object.h>
#include <living.h>
#include <sproto.h>
#include <spells.h>
#include <sounds.h>
#include <skills.h>

/*  IMPLEMENTATION NOTES  
         
         Diseases may be contageous.  They are objects which exist in a player's
inventory.  They themselves do nothing, except modify Symptoms, or 
spread to other live objects.  Symptoms are what actually damage the player:
these are their own object. */

/*  grants immunity to plagues we've seen before.  */
static int
grant_immunity (object *disease)
{
  object *immunity;
  object *walk;

  /* Don't give immunity to this disease if last_heal is set. */
  if (disease->last_heal)
    return 0;

  /*  first, search for an immunity of the same name */
  for (walk = disease->env->inv; walk; walk = walk->below)
    if (walk->type == 98 && disease->name == walk->name)
      {
        walk->level = disease->level;
        return 1;             /* just update the existing immunity. */
      }

  immunity = get_archetype ("immunity");

  immunity->name       = disease->name;
  immunity->level      = disease->level;
  immunity->move_block = 0;

  insert_ob_in_ob (immunity, disease->env);

  return 1;
}

/* argument is a disease */
static object *
find_symptom (object *disease)
{
  /* check the inventory for symptoms */
  for (object *walk = disease->env->inv; walk; walk = walk->below)
    if (walk->name == disease->name && walk->type == SYMPTOM)
      return walk;

  return NULL;
}

/* remove any symptoms of disease
 * Modified by MSW 2003-03-28 do try to find all the symptom the
 * player may have - I think through some odd interactoins with
 * disease level and player level and whatnot, a player could get
 * more than one symtpom to a disease.
 */
static int
remove_symptoms (object *disease)
{
  object *symptom, *victim = NULL;

  while ((symptom = find_symptom (disease)) != NULL)
    {
      if (!victim)
        victim = symptom->env;

      symptom->destroy ();
    }

  if (victim)
    victim->update_stats ();

  return 0;
}

/*  searches around for more victims to infect */
static int
check_infection (object *disease)
{
  int range = abs (disease->magic);

  object *op = disease->outer_env_or_self ();

  if (!op->is_on_map ())
    return 0;

  unordered_mapwalk (op, -range, -range, range, range)
    {
      mapspace &ms = m->at (nx, ny);

      if (ms.flags () & P_IS_ALIVE)
        for (object *tmp = ms.bot; tmp; tmp = tmp->above)
          infect_object (tmp, disease, 0);
    }

  return 1;
}

/* check if victim is susceptible to disease. */
static int
is_susceptible_to_disease (object *victim, object *disease)
{
  if (!QUERY_FLAG (victim, FLAG_ALIVE))
    return 0;

  if (victim->flag [FLAG_WIZ])
    return 0;

  if (disease->race.contains ("*") && !QUERY_FLAG (victim, FLAG_UNDEAD))
    return 1;

  if ((disease->race == shstr_undead) && QUERY_FLAG (victim, FLAG_UNDEAD))
    return 1;

  if ((victim->race && disease->race.contains (victim->race)) || disease->race.contains (victim->name))
    return 1;

  return 0;
}

/*  this function monitors the symptoms caused by the disease (if any),
causes symptoms, and modifies existing symptoms in the case of
existing diseases.  */
static int
do_symptoms (object *disease)
{
  object *symptom;
  object *victim;
  object *tmp;

  victim = disease->env;

  if (!victim)
    return 0;                   /* no-one to inflict symptoms on */

  /* This is a quick hack - for whatever reason, disease->env will point
   * back to disease, causing endless loops.  Why this happens really needs
   * to be found, but this should at least prevent the infinite loops.
   */
  //TODO: should no longer be the case, monitor, and remove
  if (victim == disease)
    {
      LOG (llevError | logBacktrace, "%s: disease->env points to itself", disease->debug_desc ());
      return 0;
    }

  symptom = find_symptom (disease);
  if (!symptom)
    {
      /* no symptom?  need to generate one! */

      /* first check and see if the carrier of the disease is immune.  If so, no symptoms!  */
      if (!is_susceptible_to_disease (victim, disease))
        return 0;

      /* check for an actual immunity */
      /* do an immunity check */
      for (tmp = victim->head_ ()->inv; tmp; tmp = tmp->below)
        if (tmp->type == SIGN)        /* possibly an immunity, or diseased */
          if (tmp->name == disease->name && tmp->level >= disease->level)
            return 0;         /* Immune! */

      object *new_symptom = get_archetype ("symptom");

      /* Something special done with dam.  We want diseases to be more
       * random in what they'll kill, so we'll make the damage they
       * do random, note, this has a weird effect with progressive diseases.
       */
      if (disease->stats.dam)
        {
          int dam = disease->stats.dam;

          /* reduce the damage, on average, 50%, and making things random. */

          dam = random_roll (1, abs (dam), victim, PREFER_LOW);
          if (disease->stats.dam < 0)
            dam = -dam;

          new_symptom->stats.dam = dam;
        }

      new_symptom->stats.maxsp = disease->stats.maxsp;
      new_symptom->stats.food  = new_symptom->stats.maxgrace;

      new_symptom->name = new_symptom->name_pl = disease->name;

      new_symptom->level = disease->level;
      new_symptom->speed = disease->speed;
      new_symptom->value = 0;

      for (int i = 0; i < NUM_STATS; ++i)
        new_symptom->stats.stat (i) = disease->stats.stat (i);

      new_symptom->stats.sp    = disease->stats.sp;
      new_symptom->stats.food  = disease->last_eat;
      new_symptom->stats.maxsp = disease->stats.maxsp;
      new_symptom->last_sp     = disease->last_sp;
      new_symptom->stats.exp   = 0;
      new_symptom->stats.hp    = disease->stats.hp;
      new_symptom->msg         = disease->msg;
      new_symptom->attacktype  = disease->attacktype;
      new_symptom->other_arch  = disease->other_arch;
      new_symptom->skill       = disease->skill;

      new_symptom->move_block = 0;

      victim->head_ ()->insert (new_symptom);

      // set owner last, as insert clears owner
      new_symptom->set_owner (disease->owner);

      return 1;
    }

  /* now deal with progressing diseases: we increase the debility
   * caused by the symptoms.
   */
  if (disease->stats.ac)
    {
      symptom->value = clamp (symptom->value + disease->stats.ac, 0, 100*100);

      float scale = 1.f + symptom->value / 100.f;

      /* now rescale all the debilities */
      for (int i = 0; i < NUM_STATS; ++i)
        symptom->stats.stat (i) = clamp (int (scale * disease->stats.stat (i)), -128, 127);

      symptom->stats.dam   = clamp (scale * disease->stats.dam  , -1024, 1024);
      symptom->stats.food  = clamp (scale * disease->last_eat   , -1024, 1024);
      symptom->stats.maxsp = clamp (scale * disease->stats.maxsp, -1024, 1024);
      symptom->stats.sp    = clamp (scale * disease->stats.sp   , -1024, 1024);
      symptom->stats.hp    = clamp (scale * disease->stats.hp   , -1024, 1024);
      symptom->stats.exp   = 0;
      symptom->last_sp     = disease->last_sp ? clamp (disease->last_sp / scale, 1, 1024) : 0;
      symptom->msg         = disease->msg;
      symptom->attacktype  = disease->attacktype;
      symptom->other_arch  = disease->other_arch;
    }

  SET_FLAG (symptom, FLAG_APPLIED);
  victim->update_stats ();

  return 1;
}

int
move_disease (object *disease)
{
  /* First task is to determine if the disease is inside or outside of someone.
   * If outside, we decrement 'value' until we're gone. 
   */

  if (!disease->env)
    {                           /* we're outside of someone */
      if (disease->stats.maxhp > 0)
        disease->value--;

      if (!disease->value)
        {
          disease->destroy ();
          return 1;
        }
    }
  else
    {
      /* if we're inside a person, have the disease run its course */
      /* negative/zero food denotes "perpetual" diseases. */
      if (disease->stats.food > 0)
        {
          disease->stats.food--;

          if (!disease->stats.food)
            {
              remove_symptoms (disease);        /* remove the symptoms of this disease */
              grant_immunity (disease);
              disease->destroy ();
              return 1;
            }
        }
    }

  /*  check to see if we infect others */
  check_infection (disease);

  /* impose or modify the symptoms of the disease */
  if (disease->env && is_susceptible_to_disease (disease->env, disease))
    do_symptoms (disease);

  return 0;
}

/*  check to see if an object is infectable:
 *       objects with immunity aren't infectable.
 *       objects already infected aren't infectable.
 *       dead objects aren't infectable.
 *       undead objects are infectible only if specifically named.
*/
int
infect_object (object *victim, object *disease, int force)
{
  object *tmp;
  object *new_disease;

  /* don't infect inanimate objects */
  if (!QUERY_FLAG (victim, FLAG_MONSTER) && !(victim->type == PLAYER))
    return 0;

  /* check and see if victim can catch disease:  diseases
   *  are specific 
   */
  if (!is_susceptible_to_disease (victim, disease))
    return 0;

  /* roll the dice on infection before doing the inventory check!  */
  if (!force && (random_roll (0, 126, victim, PREFER_HIGH) >= disease->stats.wc))
    return 0;

  /* do an immunity check */

  /* There used to (IMO) be a flaw in the below - it used to be the case
   * that if level check was done for both immunity and disease. This could
   * result in a person with multiple afflictions of the same disease
   * (eg, level 1 cold, level 2 cold, level 3 cold, etc), as long as
   * they were cast in that same order.  Instead, change it so that
   * if you diseased, you can't get diseased more.
   */

  for (tmp = victim->head_ ()->inv; tmp; tmp = tmp->below)
    if (tmp->type == SIGN && tmp->name == disease->name && tmp->level >= disease->level)
      return 0;               /* Immune! */
    else if (tmp->type == DISEASE && tmp->name == disease->name)
      return 0;               /* already diseased */

  /*  If we've gotten this far, go ahead and infect the victim.  */

  new_disease = disease->clone ();

  new_disease->stats.food = disease->stats.maxgrace;
  new_disease->value      = disease->stats.maxhp;
  new_disease->stats.wc  -= disease->last_grace; /* self-limiting factor */

  /* This appears to be a horrible case of overloading 'NO_PASS'
   * for meaning in the diseases.
   */
  new_disease->move_block = 0;

  // insert before setting the owner
  victim->head_ ()->insert (new_disease);

  if (disease->owner)
    new_disease->set_owner (disease->owner);
  else if (object *pl = disease->in_player ())
    /* for diseases which are passed by hitting, set owner and skill */
    new_disease->set_owner (pl);

  if (new_disease->owner && new_disease->owner->type == PLAYER)
    {
      const char *buf;

      /* if the disease has a title, it has a special infection message
       * This messages is printed in the form MESSAGE victim 
       */
      if (new_disease->title)
        buf = format ("%s %s!!", &disease->title, &victim->name);
      else
        buf = format ("You infect %s with your disease, %s!", &victim->name, &new_disease->name);

      if (victim->type == PLAYER)
        new_draw_info (NDI_UNIQUE | NDI_RED, 0, new_disease->owner, buf);
      else
        new_draw_info (0, 4, new_disease->owner, buf);
    }

  if (victim->type == PLAYER)
    new_draw_info (NDI_UNIQUE | NDI_RED, 0, victim, "You suddenly feel ill.");

  return 1;
}

/*  make the symptom do the nasty things it does  */
int
move_symptom (object *symptom)
{
  object *victim = symptom->env;
  object *new_ob;
  int sp_reduce;

  if (!victim || !victim->map)
    {                           /* outside a monster/player, die immediately */
      symptom->destroy ();
      return 0;
    }

  if (symptom->stats.dam > 0)
    hit_player (victim, symptom->stats.dam, symptom, symptom->attacktype, 1);
  else
    hit_player (victim, max (1, -victim->stats.maxhp * symptom->stats.dam / 100), symptom, symptom->attacktype, 1);

  if (symptom->stats.maxsp > 0)
    sp_reduce = symptom->stats.maxsp;
  else
    sp_reduce = max (1, victim->stats.maxsp * symptom->stats.maxsp / 100);

  victim->stats.sp = max (0, victim->stats.sp - sp_reduce);

  /* create the symptom "other arch" object and drop it here 
   * under every part of the monster
   * The victim may well have died. 
   */
  if (victim->map)
    {
      victim->play_sound (symptom->sound);

      if (symptom->other_arch)
        for (object *tmp = victim->head_ (); tmp; tmp = tmp->more)
          {
            new_ob = arch_to_object (symptom->other_arch);
            new_ob->x = tmp->x;
            new_ob->y = tmp->y;
            new_ob->map = victim->map;
            insert_ob_in_map (new_ob, victim->map, victim, 0);
          }
    }

  new_draw_info (NDI_UNIQUE | NDI_RED, 0, victim, symptom->msg);

  return 1;
}

/* possibly infect due to direct physical contact
 * i.e., AT_PHYSICAL-- called from "hit_player_attacktype" */
int
check_physically_infect (object *victim, object *hitter)
{
  /* search for diseases, give every disease a chance to infect */
  for (object *disease = hitter->inv; disease; disease = disease->below)
    if (disease->type == DISEASE)
      infect_object (victim, disease, 0);

  return 1;
}

// find a disease in someone
object *
find_disease (object *victim)
{
  for (object *disease = victim->inv; disease; disease = disease->below)
    if (disease->type == DISEASE)
      return disease;

  return 0;
}

/* do the cure disease stuff, from the spell "cure disease" */
int
cure_disease (object *sufferer, object *caster, object *spell)
{
  object *disease, *next;
  int cure = 0;

  int casting_level = caster ? caster->level : 1000;       /* if null caster, CURE all.  */

  for (disease = sufferer->inv; disease; disease = next)
    {
      next = disease->below;

      if (disease->type == DISEASE)
        {                       /* attempt to cure this disease */
          /* If caster level is higher than disease level, cure chance
           * is automatic.  If lower, then the chance is basically
           * 1 in level_diff - if there is a 5 level difference, chance
           * is 1 in 5.
           */
          if ((casting_level >= disease->level) || (!(random_roll (0, (disease->level - casting_level - 1), caster, PREFER_LOW))))
            {
              remove_symptoms (disease);
              cure = 1;

              if (caster && spell)
                change_exp (caster, disease->stats.exp, spell->skill, SK_EXP_SKILL_ONLY);

              disease->destroy ();
            }
        }
    }

  if (cure)
    {
      /* Only draw these messages once */
      if (caster)
        new_draw_info_format (NDI_UNIQUE, 0, caster, "You cure a disease!");

      new_draw_info (NDI_UNIQUE, 0, sufferer, "You no longer feel diseased.");
    }

  return 1;
}

/* reduces disease progression:  reduce_symptoms 
 * return true if we actually reduce a disease.
 */
int
reduce_symptoms (object *sufferer, int reduction)
{
  object *walk;
  int success = 0;

  for (walk = sufferer->inv; walk; walk = walk->below)
    {
      if (walk->type == SYMPTOM)
        {
          if (walk->value > 0)
            {
              success = 1;
              walk->value = max (0, walk->value - 2 * reduction);
              /* give the disease time to modify this symptom,
               * and reduce its severity.  */
              walk->speed_left = 0;
            }
        }
    }

  if (success)
    new_draw_info (NDI_UNIQUE, 0, sufferer, "Your illness seems less severe.");

  return success;
}
Revision:	1.53
Committed:	Mon Oct 12 14:00:59 2009 UTC (14 years, 7 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-2_82, rel-2_81
Changes since 1.52:	+7 -6 lines
Log Message:	clarify license
#	Content
1	/*
2	* This file is part of Deliantra, the Roguelike Realtime MMORPG.
3	*
4	* Copyright (©) 2005,2006,2007,2008,2009 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
5	* Copyright (©) 2002,2007 Mark Wedel & Crossfire Development Team
6	* Copyright (©) 1992,2007 Frank Tore Johansen
7	*
8	* Deliantra is free software: you can redistribute it and/or modify it under
9	* the terms of the Affero GNU General Public License as published by the
10	* Free Software Foundation, either version 3 of the License, or (at your
11	* option) any later version.
12	*
13	* This program is distributed in the hope that it will be useful,
14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16	* GNU General Public License for more details.
17	*
18	* You should have received a copy of the Affero GNU General Public License
19	* and the GNU General Public License along with this program. If not, see
20	* <http://www.gnu.org/licenses/>.
21	*
22	* The authors can be reached via e-mail to <support@deliantra.net>
23	*/
24
25	/* This file contains all the code implementing diseases,
26	* except for odds and ends in attack.c and in
27	* living.c
28	*/
29
30	/*
31
32	For DISEASES:
33	Stat Property Definition
34
35	attacktype Attack effects Attacktype of the disease. usu. AT_GODPOWER.
36	other_arch Creation object created and dropped when symptom moved.
37	title Message When the "disease" "infects" something, it will
38	print "title victim!!!" to the player who owns
39	the "disease".
40	wc+ Infectiousness How well the plague spreads person-to-person
41	magic+ Range range of infection
42	Stats* Disability What stats are reduced by the disease (str con...)
43	maxhp+ Persistence How long the disease can last OUTSIDE the host.
44	value TimeLeft Counter for persistence
45	dam^ Damage How much damage it does (%?).
46	maxgrace+ Duration How long before the disease is naturally cured.
47	food DurCount Counter for Duration
48
49	speed Speed How often the disease moves.
50	last_sp^ Lethargy Percentage of max speed. 10 = 10% speed.
51
52	maxsp^ Mana deplete Saps mana.
53	ac^ Progressiveness How the diseases increases in severity.
54	last_eat*^ Deplete food saps food if negative
55	last_heal GrantImmunity If nonzero, disease does NOT grant immunity
56	when it runs out
57
58	exp experience experience awarded when plague cured
59	hp*^ ReduceRegen reduces regeneration of disease-bearer
60	sp*^ ReduceSpRegen reduces spellpoint regeneration
61
62	name Name Name of the plague
63	msg message What the plague says when it strikes.
64	race those affected species/race the plague strikes (* = everything)
65	level Plague Level General description of the plague's deadliness
66	armour Attenuation reduction in wc per generation of disease.
67	This builds in a self-limiting factor.
68
69
70	Explanations:
71	* means this # should be negative to cause adverse effect.
72	+ means that this effect is modulated in spells by ldur
73	^ means that this effect is modulated in spells by ldam
74
75	attacktype is the attacktype used by the disease to smite "dam" damage with.
76
77	wc/127 is the chance of someone in range catching it.
78
79	magic is the range at which infection may occur. If negative, the range is
80	NOT level dependent.
81
82	Stats are stat modifications. These should typically be negative.
83
84	maxhp is how long the disease will persist if the host dies and "drops" it,
85	in "disease moves", i.e., moves of the disease. If negative, permanent.
86
87
88	value is the counter for maxhp, it starts at maxhp and drops...
89
90	dam if positive, it is straight damage. if negative, a %-age.
91
92	maxgrace how long in "disease moves" the disease lasts in the host, if negative,
93	permanent until cured.
94
95	food if negative, disease is permanent. otherwise, decreases at <speed>,
96	disease goes away at food=0, set to "maxgrace" on infection.
97
98	speed is the speed of the disease, how fast "disease moves" occur.
99
100	last_sp is the lethargy imposed on the player by the disease. A lethargy
101	of "1" reduces the players speed to 1% of its normal value.
102
103	maxsp how much mana is sapped per "disease move". if negative, a %-age is
104	taken.
105
106	ac every "disease move" the severity of the symptoms are increased by
107	ac/100. (severity = 1 + (accumlated_progression)/100)
108
109	last_eat increases food usage if negative.
110
111
112
113	For SYMPTOMS:
114
115	Stats modify stats
116	hp modify regen
117	value progression counter (multiplier = value/100)
118	food modify food use (from last_eat in DISEASE)
119	maxsp suck mana ( as noted for DISEASE)
120	last_sp Lethargy
121	msg What to say
122	speed speed of movement, from DISEASE
123
124
125	*/
126
127
128	#include <global.h>
129	#include <object.h>
130	#include <living.h>
131	#include <sproto.h>
132	#include <spells.h>
133	#include <sounds.h>
134	#include <skills.h>
135
136	/* IMPLEMENTATION NOTES
137
138	Diseases may be contageous. They are objects which exist in a player's
139	inventory. They themselves do nothing, except modify Symptoms, or
140	spread to other live objects. Symptoms are what actually damage the player:
141	these are their own object. */
142
143	/* grants immunity to plagues we've seen before. */
144	static int
145	grant_immunity (object *disease)
146	{
147	object *immunity;
148	object *walk;
149
150	/* Don't give immunity to this disease if last_heal is set. */
151	if (disease->last_heal)
152	return 0;
153
154	/* first, search for an immunity of the same name */
155	for (walk = disease->env->inv; walk; walk = walk->below)
156	if (walk->type == 98 && disease->name == walk->name)
157	{
158	walk->level = disease->level;
159	return 1; /* just update the existing immunity. */
160	}
161
162	immunity = get_archetype ("immunity");
163
164	immunity->name = disease->name;
165	immunity->level = disease->level;
166	immunity->move_block = 0;
167
168	insert_ob_in_ob (immunity, disease->env);
169
170	return 1;
171	}
172
173	/* argument is a disease */
174	static object *
175	find_symptom (object *disease)
176	{
177	/* check the inventory for symptoms */
178	for (object *walk = disease->env->inv; walk; walk = walk->below)
179	if (walk->name == disease->name && walk->type == SYMPTOM)
180	return walk;
181
182	return NULL;
183	}
184
185	/* remove any symptoms of disease
186	* Modified by MSW 2003-03-28 do try to find all the symptom the
187	* player may have - I think through some odd interactoins with
188	* disease level and player level and whatnot, a player could get
189	* more than one symtpom to a disease.
190	*/
191	static int
192	remove_symptoms (object *disease)
193	{
194	object symptom, victim = NULL;
195
196	while ((symptom = find_symptom (disease)) != NULL)
197	{
198	if (!victim)
199	victim = symptom->env;
200
201	symptom->destroy ();
202	}
203
204	if (victim)
205	victim->update_stats ();
206
207	return 0;
208	}
209
210	/* searches around for more victims to infect */
211	static int
212	check_infection (object *disease)
213	{
214	int range = abs (disease->magic);
215
216	object *op = disease->outer_env_or_self ();
217
218	if (!op->is_on_map ())
219	return 0;
220
221	unordered_mapwalk (op, -range, -range, range, range)
222	{
223	mapspace &ms = m->at (nx, ny);
224
225	if (ms.flags () & P_IS_ALIVE)
226	for (object *tmp = ms.bot; tmp; tmp = tmp->above)
227	infect_object (tmp, disease, 0);
228	}
229
230	return 1;
231	}
232
233	/* check if victim is susceptible to disease. */
234	static int
235	is_susceptible_to_disease (object victim, object disease)
236	{
237	if (!QUERY_FLAG (victim, FLAG_ALIVE))
238	return 0;
239
240	if (victim->flag [FLAG_WIZ])
241	return 0;
242
243	if (disease->race.contains ("*") && !QUERY_FLAG (victim, FLAG_UNDEAD))
244	return 1;
245
246	if ((disease->race == shstr_undead) && QUERY_FLAG (victim, FLAG_UNDEAD))
247	return 1;
248
249	if ((victim->race && disease->race.contains (victim->race)) \|\| disease->race.contains (victim->name))
250	return 1;
251
252	return 0;
253	}
254
255	/* this function monitors the symptoms caused by the disease (if any),
256	causes symptoms, and modifies existing symptoms in the case of
257	existing diseases. */
258	static int
259	do_symptoms (object *disease)
260	{
261	object *symptom;
262	object *victim;
263	object *tmp;
264
265	victim = disease->env;
266
267	if (!victim)
268	return 0; /* no-one to inflict symptoms on */
269
270	/* This is a quick hack - for whatever reason, disease->env will point
271	* back to disease, causing endless loops. Why this happens really needs
272	* to be found, but this should at least prevent the infinite loops.
273	*/
274	//TODO: should no longer be the case, monitor, and remove
275	if (victim == disease)
276	{
277	LOG (llevError \| logBacktrace, "%s: disease->env points to itself", disease->debug_desc ());
278	return 0;
279	}
280
281	symptom = find_symptom (disease);
282	if (!symptom)
283	{
284	/* no symptom? need to generate one! */
285
286	/* first check and see if the carrier of the disease is immune. If so, no symptoms! */
287	if (!is_susceptible_to_disease (victim, disease))
288	return 0;
289
290	/* check for an actual immunity */
291	/* do an immunity check */
292	for (tmp = victim->head_ ()->inv; tmp; tmp = tmp->below)
293	if (tmp->type == SIGN) /* possibly an immunity, or diseased */
294	if (tmp->name == disease->name && tmp->level >= disease->level)
295	return 0; /* Immune! */
296
297	object *new_symptom = get_archetype ("symptom");
298
299	/* Something special done with dam. We want diseases to be more
300	* random in what they'll kill, so we'll make the damage they
301	* do random, note, this has a weird effect with progressive diseases.
302	*/
303	if (disease->stats.dam)
304	{
305	int dam = disease->stats.dam;
306
307	/* reduce the damage, on average, 50%, and making things random. */
308
309	dam = random_roll (1, abs (dam), victim, PREFER_LOW);
310	if (disease->stats.dam < 0)
311	dam = -dam;
312
313	new_symptom->stats.dam = dam;
314	}
315
316	new_symptom->stats.maxsp = disease->stats.maxsp;
317	new_symptom->stats.food = new_symptom->stats.maxgrace;
318
319	new_symptom->name = new_symptom->name_pl = disease->name;
320
321	new_symptom->level = disease->level;
322	new_symptom->speed = disease->speed;
323	new_symptom->value = 0;
324
325	for (int i = 0; i < NUM_STATS; ++i)
326	new_symptom->stats.stat (i) = disease->stats.stat (i);
327
328	new_symptom->stats.sp = disease->stats.sp;
329	new_symptom->stats.food = disease->last_eat;
330	new_symptom->stats.maxsp = disease->stats.maxsp;
331	new_symptom->last_sp = disease->last_sp;
332	new_symptom->stats.exp = 0;
333	new_symptom->stats.hp = disease->stats.hp;
334	new_symptom->msg = disease->msg;
335	new_symptom->attacktype = disease->attacktype;
336	new_symptom->other_arch = disease->other_arch;
337	new_symptom->skill = disease->skill;
338
339	new_symptom->move_block = 0;
340
341	victim->head_ ()->insert (new_symptom);
342
343	// set owner last, as insert clears owner
344	new_symptom->set_owner (disease->owner);
345
346	return 1;
347	}
348
349	/* now deal with progressing diseases: we increase the debility
350	* caused by the symptoms.
351	*/
352	if (disease->stats.ac)
353	{
354	symptom->value = clamp (symptom->value + disease->stats.ac, 0, 100*100);
355
356	float scale = 1.f + symptom->value / 100.f;
357
358	/* now rescale all the debilities */
359	for (int i = 0; i < NUM_STATS; ++i)
360	symptom->stats.stat (i) = clamp (int (scale * disease->stats.stat (i)), -128, 127);
361
362	symptom->stats.dam = clamp (scale * disease->stats.dam , -1024, 1024);
363	symptom->stats.food = clamp (scale * disease->last_eat , -1024, 1024);
364	symptom->stats.maxsp = clamp (scale * disease->stats.maxsp, -1024, 1024);
365	symptom->stats.sp = clamp (scale * disease->stats.sp , -1024, 1024);
366	symptom->stats.hp = clamp (scale * disease->stats.hp , -1024, 1024);
367	symptom->stats.exp = 0;
368	symptom->last_sp = disease->last_sp ? clamp (disease->last_sp / scale, 1, 1024) : 0;
369	symptom->msg = disease->msg;
370	symptom->attacktype = disease->attacktype;
371	symptom->other_arch = disease->other_arch;
372	}
373
374	SET_FLAG (symptom, FLAG_APPLIED);
375	victim->update_stats ();
376
377	return 1;
378	}
379
380	int
381	move_disease (object *disease)
382	{
383	/* First task is to determine if the disease is inside or outside of someone.
384	* If outside, we decrement 'value' until we're gone.
385	*/
386
387	if (!disease->env)
388	{ /* we're outside of someone */
389	if (disease->stats.maxhp > 0)
390	disease->value--;
391
392	if (!disease->value)
393	{
394	disease->destroy ();
395	return 1;
396	}
397	}
398	else
399	{
400	/* if we're inside a person, have the disease run its course */
401	/* negative/zero food denotes "perpetual" diseases. */
402	if (disease->stats.food > 0)
403	{
404	disease->stats.food--;
405
406	if (!disease->stats.food)
407	{
408	remove_symptoms (disease); /* remove the symptoms of this disease */
409	grant_immunity (disease);
410	disease->destroy ();
411	return 1;
412	}
413	}
414	}
415
416	/* check to see if we infect others */
417	check_infection (disease);
418
419	/* impose or modify the symptoms of the disease */
420	if (disease->env && is_susceptible_to_disease (disease->env, disease))
421	do_symptoms (disease);
422
423	return 0;
424	}
425
426	/* check to see if an object is infectable:
427	* objects with immunity aren't infectable.
428	* objects already infected aren't infectable.
429	* dead objects aren't infectable.
430	* undead objects are infectible only if specifically named.
431	*/
432	int
433	infect_object (object victim, object disease, int force)
434	{
435	object *tmp;
436	object *new_disease;
437
438	/* don't infect inanimate objects */
439	if (!QUERY_FLAG (victim, FLAG_MONSTER) && !(victim->type == PLAYER))
440	return 0;
441
442	/* check and see if victim can catch disease: diseases
443	* are specific
444	*/
445	if (!is_susceptible_to_disease (victim, disease))
446	return 0;
447
448	/* roll the dice on infection before doing the inventory check! */
449	if (!force && (random_roll (0, 126, victim, PREFER_HIGH) >= disease->stats.wc))
450	return 0;
451
452	/* do an immunity check */
453
454	/* There used to (IMO) be a flaw in the below - it used to be the case
455	* that if level check was done for both immunity and disease. This could
456	* result in a person with multiple afflictions of the same disease
457	* (eg, level 1 cold, level 2 cold, level 3 cold, etc), as long as
458	* they were cast in that same order. Instead, change it so that
459	* if you diseased, you can't get diseased more.
460	*/
461
462	for (tmp = victim->head_ ()->inv; tmp; tmp = tmp->below)
463	if (tmp->type == SIGN && tmp->name == disease->name && tmp->level >= disease->level)
464	return 0; /* Immune! */
465	else if (tmp->type == DISEASE && tmp->name == disease->name)
466	return 0; /* already diseased */
467
468	/* If we've gotten this far, go ahead and infect the victim. */
469
470	new_disease = disease->clone ();
471
472	new_disease->stats.food = disease->stats.maxgrace;
473	new_disease->value = disease->stats.maxhp;
474	new_disease->stats.wc -= disease->last_grace; /* self-limiting factor */
475
476	/* This appears to be a horrible case of overloading 'NO_PASS'
477	* for meaning in the diseases.
478	*/
479	new_disease->move_block = 0;
480
481	// insert before setting the owner
482	victim->head_ ()->insert (new_disease);
483
484	if (disease->owner)
485	new_disease->set_owner (disease->owner);
486	else if (object *pl = disease->in_player ())
487	/* for diseases which are passed by hitting, set owner and skill */
488	new_disease->set_owner (pl);
489
490	if (new_disease->owner && new_disease->owner->type == PLAYER)
491	{
492	const char *buf;
493
494	/* if the disease has a title, it has a special infection message
495	* This messages is printed in the form MESSAGE victim
496	*/
497	if (new_disease->title)
498	buf = format ("%s %s!!", &disease->title, &victim->name);
499	else
500	buf = format ("You infect %s with your disease, %s!", &victim->name, &new_disease->name);
501
502	if (victim->type == PLAYER)
503	new_draw_info (NDI_UNIQUE \| NDI_RED, 0, new_disease->owner, buf);
504	else
505	new_draw_info (0, 4, new_disease->owner, buf);
506	}
507
508	if (victim->type == PLAYER)
509	new_draw_info (NDI_UNIQUE \| NDI_RED, 0, victim, "You suddenly feel ill.");
510
511	return 1;
512	}
513
514	/* make the symptom do the nasty things it does */
515	int
516	move_symptom (object *symptom)
517	{
518	object *victim = symptom->env;
519	object *new_ob;
520	int sp_reduce;
521
522	if (!victim \|\| !victim->map)
523	{ /* outside a monster/player, die immediately */
524	symptom->destroy ();
525	return 0;
526	}
527
528	if (symptom->stats.dam > 0)
529	hit_player (victim, symptom->stats.dam, symptom, symptom->attacktype, 1);
530	else
531	hit_player (victim, max (1, -victim->stats.maxhp * symptom->stats.dam / 100), symptom, symptom->attacktype, 1);
532
533	if (symptom->stats.maxsp > 0)
534	sp_reduce = symptom->stats.maxsp;
535	else
536	sp_reduce = max (1, victim->stats.maxsp * symptom->stats.maxsp / 100);
537
538	victim->stats.sp = max (0, victim->stats.sp - sp_reduce);
539
540	/* create the symptom "other arch" object and drop it here
541	* under every part of the monster
542	* The victim may well have died.
543	*/
544	if (victim->map)
545	{
546	victim->play_sound (symptom->sound);
547
548	if (symptom->other_arch)
549	for (object *tmp = victim->head_ (); tmp; tmp = tmp->more)
550	{
551	new_ob = arch_to_object (symptom->other_arch);
552	new_ob->x = tmp->x;
553	new_ob->y = tmp->y;
554	new_ob->map = victim->map;
555	insert_ob_in_map (new_ob, victim->map, victim, 0);
556	}
557	}
558
559	new_draw_info (NDI_UNIQUE \| NDI_RED, 0, victim, symptom->msg);
560
561	return 1;
562	}
563
564	/* possibly infect due to direct physical contact
565	* i.e., AT_PHYSICAL-- called from "hit_player_attacktype" */
566	int
567	check_physically_infect (object victim, object hitter)
568	{
569	/* search for diseases, give every disease a chance to infect */
570	for (object *disease = hitter->inv; disease; disease = disease->below)
571	if (disease->type == DISEASE)
572	infect_object (victim, disease, 0);
573
574	return 1;
575	}
576
577	// find a disease in someone
578	object *
579	find_disease (object *victim)
580	{
581	for (object *disease = victim->inv; disease; disease = disease->below)
582	if (disease->type == DISEASE)
583	return disease;
584
585	return 0;
586	}
587
588	/* do the cure disease stuff, from the spell "cure disease" */
589	int
590	cure_disease (object sufferer, object caster, object *spell)
591	{
592	object disease, next;
593	int cure = 0;
594
595	int casting_level = caster ? caster->level : 1000; /* if null caster, CURE all. */
596
597	for (disease = sufferer->inv; disease; disease = next)
598	{
599	next = disease->below;
600
601	if (disease->type == DISEASE)
602	{ /* attempt to cure this disease */
603	/* If caster level is higher than disease level, cure chance
604	* is automatic. If lower, then the chance is basically
605	* 1 in level_diff - if there is a 5 level difference, chance
606	* is 1 in 5.
607	*/
608	if ((casting_level >= disease->level) \|\| (!(random_roll (0, (disease->level - casting_level - 1), caster, PREFER_LOW))))
609	{
610	remove_symptoms (disease);
611	cure = 1;
612
613	if (caster && spell)
614	change_exp (caster, disease->stats.exp, spell->skill, SK_EXP_SKILL_ONLY);
615
616	disease->destroy ();
617	}
618	}
619	}
620
621	if (cure)
622	{
623	/* Only draw these messages once */
624	if (caster)
625	new_draw_info_format (NDI_UNIQUE, 0, caster, "You cure a disease!");
626
627	new_draw_info (NDI_UNIQUE, 0, sufferer, "You no longer feel diseased.");
628	}
629
630	return 1;
631	}
632
633	/* reduces disease progression: reduce_symptoms
634	* return true if we actually reduce a disease.
635	*/
636	int
637	reduce_symptoms (object *sufferer, int reduction)
638	{
639	object *walk;
640	int success = 0;
641
642	for (walk = sufferer->inv; walk; walk = walk->below)
643	{
644	if (walk->type == SYMPTOM)
645	{
646	if (walk->value > 0)
647	{
648	success = 1;
649	walk->value = max (0, walk->value - 2 * reduction);
650	/* give the disease time to modify this symptom,
651	* and reduce its severity. */
652	walk->speed_left = 0;
653	}
654	}
655	}
656
657	if (success)
658	new_draw_info (NDI_UNIQUE, 0, sufferer, "Your illness seems less severe.");
659
660	return success;
661	}