server/server/skill_util.C

/*
 * CrossFire, A Multiplayer game for X-windows
 * 
 * Copyright (C) 2005, 2006, 2007 Marc Lehmann & Crossfire+ Development Team
 * Copryight (C) 2002 Mark Wedel & Crossfire Development Team
 * Copyright (C) 1992 Frank Tore Johansen
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * The author can be reached via e-mail to <crossfire@schmorp.de>
 */

/* Created July 95 to separate skill utilities from actual skills -b.t. */

/* Reconfigured skills code to allow linking of skills to experience
 * categories. This is done solely through the init_new_exp_system() fctn.
 * June/July 1995 -b.t. thomas@astro.psu.edu
 */

/* July 1995 - Initial associated skills coding. Experience gains
 * come solely from the use of skills. Overcoming an opponent (in combat,
 * finding/disarming a trap, stealing from somebeing, etc) gains
 * experience. Calc_skill_exp() handles the gained experience using
 * modifications in the skills[] table. - b.t.
 */

/* define the following for skills utility debuging */

/* #define SKILL_UTIL_DEBUG */

#include <global.h>
#include <object.h>
#include <sproto.h>
#include <living.h>             /* for defs of STR,CON,DEX,etc. -b.t. */
#include <spells.h>

const uint8_t skill_flags[NUM_SKILLS] = {
  0, // SK_NONE
# define def(uc, flags) flags,
#  include "skillinc.h"
# undef def
};

static int attack_hth (object *pl, int dir, const char *string, object *skill);
static int attack_melee_weapon (object *op, int dir, const char *string, object *skill);

/* init_skills basically just sets up the skill_names table
 * above.  The index into the array is set up by the
 * subtypes.
 */
void
init_skills (void)
{
  for (archetype *at = first_archetype; at; at = at->next)
    if (at->clone.type == SKILL)
      {
        if (skill_names[at->clone.subtype])
          LOG (llevError, "init_skills: multiple skill using same subtype %d, %s, %s\n",
               at->clone.subtype, &skill_names[at->clone.subtype], &at->clone.skill);
        else
          skill_names[at->clone.subtype] = at->clone.skill;
      }

  /* This isn't really an error if there is no skill subtype set, but
   * checking for this may catch some user errors.
   */
  for (int i = 1; i < NUM_SKILLS; i++)
    if (!skill_names[i])
      LOG (llevError, "init_skills: skill subtype %d doesn't have a name?\n", i);
}

/* This function goes through the player inventory and sets
 * up the last_skills[] array in the player object.
 * the last_skills[] is used to more quickly lookup skills - 
 * mostly used for sending exp.
 */
void
link_player_skills (object *op)
{
  for (object *tmp = op->inv; tmp; tmp = tmp->below)
    if (tmp->type == SKILL)
      {
        /* This is really a warning, hence no else below */
        if (op->contr->last_skill_ob[tmp->subtype] && op->contr->last_skill_ob[tmp->subtype] != tmp)
          LOG (llevError, "Multiple skills with the same subtype? %s, %s\n",
               &op->contr->last_skill_ob[tmp->subtype]->skill, &tmp->skill);

        if (tmp->subtype >= NUM_SKILLS)
          LOG (llevError, "Invalid subtype number %d (range 0-%d)\n", tmp->subtype, NUM_SKILLS);
        else
          {
            op->contr->last_skill_ob[tmp->subtype] = tmp;
            op->contr->ns->last_skill_exp[tmp->subtype] = -1; //TODO: this should go
          }
      }
}

/* This returns the skill pointer of the given name (the
 * one that accumlates exp, has the level, etc).
 *
 * It is presumed that the player will be needing to actually
 * use the skill, so thus if use of the skill requires a skill
 * tool, this code will equip it.
 */
object *
find_skill_by_name (object *who, const char *name)
{
  object *skill = NULL, *skill_tool = NULL, *tmp;

  if (!name)
    return NULL;

  /* We make sure the length of the string in the object is greater
   * in length than the passed string. Eg, if we have a skill called
   * 'hi', we don't want to match if the user passed 'high'
   */
  for (tmp = who->inv; tmp != NULL; tmp = tmp->below)
    {
      if (tmp->type == SKILL && !strncasecmp (name, tmp->skill, strlen (name)) && (size_t) strlen (tmp->skill) >= strlen (name))
        skill = tmp;

      /* Try to find appropriate skilltool.  If the player has one already
       * applied, we try to keep using that one.
       */
      else if (tmp->type == SKILL_TOOL && !strncasecmp (name, tmp->skill, strlen (name)) && (size_t) strlen (tmp->skill) >= strlen (name))
        {
          if (QUERY_FLAG (tmp, FLAG_APPLIED))
            skill_tool = tmp;
          else if (!skill_tool || !QUERY_FLAG (skill_tool, FLAG_APPLIED))
            skill_tool = tmp;
        }
    }
  /* If this is a skill that can be used without a tool, return it */
  if (skill && QUERY_FLAG (skill, FLAG_CAN_USE_SKILL))
    return skill;

  /* Player has a tool to use the skill.  IF not applied, apply it -
   * if not successful, return null.  If they do have the skill tool
   * but not the skill itself, give it to them.
   */
  if (skill_tool)
    {
      if (!QUERY_FLAG (skill_tool, FLAG_APPLIED))
        {
          if (apply_special (who, skill_tool, 0))
            return NULL;
        }

      if (!skill)
        {
          skill = give_skill_by_name (who, skill_tool->skill);
          link_player_skills (who);
        }

      return skill;
    }

  return NULL;
}


/* This returns the skill pointer of the given name (the
 * one that accumlates exp, has the level, etc).
 *
 * It is presumed that the player will be needing to actually
 * use the skill, so thus if use of the skill requires a skill
 * tool, this code will equip it.
 * 
 * This code is basically the same as find_skill_by_name() above,
 * but instead a skill name, we search by matching number.
 * this replaces find_skill.
 */
object *
find_skill_by_number (object *who, int skillno)
{
  object *skill = NULL, *skill_tool = NULL, *tmp;

  if (skillno < 1 || skillno >= NUM_SKILLS)
    return NULL;

  for (tmp = who->inv; tmp != NULL; tmp = tmp->below)
    {
      if (tmp->type == SKILL && tmp->subtype == skillno)
        skill = tmp;

      /* Try to find appropriate skilltool.  If the player has one already
       * applied, we try to keep using that one.
       */
      else if (tmp->type == SKILL_TOOL && tmp->subtype == skillno)
        {
          if (QUERY_FLAG (tmp, FLAG_APPLIED))
            skill_tool = tmp;
          else if (!skill_tool || !QUERY_FLAG (skill_tool, FLAG_APPLIED))
            skill_tool = tmp;
        }
    }
  /* If this is a skill that can be used without a tool, return it */
  if (skill && QUERY_FLAG (skill, FLAG_CAN_USE_SKILL))
    return skill;

  /* Player has a tool to use the skill.  IF not applied, apply it -
   * if not successful, return null.  If they do have the skill tool
   * but not the skill itself, give it to them.
   */
  if (skill_tool)
    {
      if (!QUERY_FLAG (skill_tool, FLAG_APPLIED))
        {
          if (apply_special (who, skill_tool, 0))
            return NULL;
        }

      if (!skill)
        {
          skill = give_skill_by_name (who, skill_tool->skill);
          link_player_skills (who);
        }

      return skill;
    }

  return NULL;
}

/* This changes the objects skill to new_skill.
 * note that this function doesn't always need to get used -
 * you can now add skill exp to the player without the chosen_skill being
 * set.  This function is of most interest to players to update
 * the various range information.
 * if new_skill is null, this just unapplies the skill.
 * flag has the current meaning:
 * 0x1: If set, don't update the range pointer.  This is useful when we
 *   need to ready a new skill, but don't want to clobber range.
 * return 1 on success, 0 on error
 */
int
change_skill (object *who, object *new_skill, int flag)
{
  int old_range;

  if (who->type != PLAYER)
    return 0;

  player *pl = who->contr;

  if (pl->ranged_skill && pl->ranged_skill == new_skill)
    return 1;

  if (!new_skill)
    {
      if (pl->ranged_skill)
        apply_special (who, pl->ranged_skill, AP_UNAPPLY);

      /* Only goal in this case was to unapply a skill */
      return 0;
    }

  // move skill to front, so it will be preferred next time
  new_skill->remove ();
  who->insert (new_skill);

  if (apply_special (who, new_skill, AP_APPLY))
    return 0;

  return 1;
}

/* This function just clears the chosen_skill and range_skill values
 * in the player.
 */
void
clear_skill (object *who)
{
  who->chosen_skill = 0;
  CLEAR_FLAG (who, FLAG_READY_SKILL);

  if (who->type == PLAYER)
    {
      if (who->contr->ranged_skill && who->contr->ranged_skill->type == SKILL)
        {
          who->contr->ranged_skill = 0;
          who->contr->ranged_ob    = 0;
        }
    }
}

/* do_skill() - Main skills use function-similar in scope to cast_spell(). 
 * We handle all requests for skill use outside of some combat here. 
 * We require a separate routine outside of fire() so as to allow monsters 
 * to utilize skills.  Returns 1 on use of skill, otherwise 0.
 * This is changed (2002-11-30) from the old method that returned
 * exp - no caller needed that info, but it also prevented the callers
 * from know if a skill was actually used, as many skills don't
 * give any exp for their direct use (eg, throwing).
 * It returns 0 if no skill was used.
 */
int
do_skill (object *op, object *part, object *skill, int dir, const char *string)
{
  int success = 0, exp = 0;
  int did_alc = 0;
  object *tmp, *next;

  if (!skill)
    return 0;

  /* The code below presumes that the skill points to the object that
   * holds the exp, level, etc of the skill.  So if this is a player
   * go and try to find the actual real skill pointer, and if the
   * the player doesn't have a bucket for that, create one.
   */
  if (skill->type != SKILL && op->type == PLAYER)
    {
      for (tmp = op->inv; tmp != NULL; tmp = tmp->below)
        if (tmp->type == SKILL && tmp->skill == skill->skill)
          break;

      if (!tmp)
        tmp = give_skill_by_name (op, skill->skill);

      skill = tmp;
    }

  // skill, by_whom, on_which_object, which direction, skill_argument
  if (INVOKE_OBJECT (USE_SKILL, skill, ARG_OBJECT (op), ARG_OBJECT (part), ARG_INT (dir), ARG_STRING (string)))
    return 0;

  switch (skill->subtype)
    {
      case SK_LEVITATION:
        /* Not 100% sure if this will work with new movement code -
         * the levitation skill has move_type for flying, so when
         * equipped, that should transfer to player, when not,
         * shouldn't.
         */
        if (QUERY_FLAG (skill, FLAG_APPLIED))
          {
            CLEAR_FLAG (skill, FLAG_APPLIED);
            new_draw_info (NDI_UNIQUE, 0, op, "You come to earth.");
          }
        else
          {
            SET_FLAG (skill, FLAG_APPLIED);
            new_draw_info (NDI_UNIQUE, 0, op, "You rise into the air!.");
          }

        op->update_stats ();
        success = 1;
        break;

      case SK_STEALING:
        exp = success = steal (op, dir, skill);
        break;

      case SK_LOCKPICKING:
        exp = success = pick_lock (op, dir, skill);
        break;

      case SK_HIDING:
        exp = success = hide (op, skill);
        break;

      case SK_JUMPING:
        success = jump (op, dir, skill);
        break;

      case SK_INSCRIPTION:
        exp = success = write_on_item (op, string, skill);
        break;

      case SK_MEDITATION:
        meditate (op, skill);
        success = 1;
        break;
        /* note that the following 'attack' skills gain exp through hit_player() */

      case SK_KARATE:
        attack_hth (op, dir, "karate-chopped", skill);
        break;

      case SK_PUNCHING:
        attack_hth (op, dir, "punched", skill);
        break;

      case SK_FLAME_TOUCH:
        attack_hth (op, dir, "flamed", skill);
        break;

      case SK_SPARK_TOUCH:
        attack_hth (op, dir, "zapped", skill);
        break;

      case SK_SHIVER:
        attack_hth (op, dir, "froze", skill);
        break;

      case SK_ACID_SPLASH:
        attack_hth (op, dir, "dissolved", skill);
        break;

      case SK_POISON_NAIL:
        attack_hth (op, dir, "injected poison into", skill);
        break;

      case SK_CLAWING:
        attack_hth (op, dir, "clawed", skill);
        break;

      case SK_ONE_HANDED_WEAPON:
      case SK_TWO_HANDED_WEAPON:
        attack_melee_weapon (op, dir, NULL, skill);
        break;

      case SK_FIND_TRAPS:
        exp = success = find_traps (op, skill);
        break;

      case SK_SINGING:
        exp = success = singing (op, dir, skill);
        break;

      case SK_ORATORY:
        exp = success = use_oratory (op, dir, skill);
        break;

      case SK_SMITHERY:
      case SK_BOWYER:
      case SK_JEWELER:
      case SK_ALCHEMY:
      case SK_THAUMATURGY:
      case SK_LITERACY:
      case SK_WOODSMAN:
        /* first, we try to find a cauldron, and do the alchemy thing.
         * failing that, we go and identify stuff. 
         */
        for (tmp = GET_MAP_OB (op->map, op->x, op->y); tmp != NULL; tmp = next)
          {
            next = tmp->above;

            if (QUERY_FLAG (tmp, FLAG_IS_CAULDRON))
              {
                attempt_do_alchemy (op, tmp);

                if (QUERY_FLAG (tmp, FLAG_APPLIED))
                  esrv_send_inventory (op, tmp);

                did_alc = 1;
              }
          }

        if (did_alc == 0)
          exp = success = skill_ident (op, skill);

        break;

      case SK_DET_MAGIC:
      case SK_DET_CURSE:
        exp = success = skill_ident (op, skill);
        break;

      case SK_DISARM_TRAPS:
        exp = success = remove_trap (op, dir, skill);
        break;

      case SK_THROWING:
        success = skill_throw (op, part, dir, string, skill);
        break;

      case SK_SET_TRAP:
        new_draw_info (NDI_UNIQUE, 0, op, "This skill is not currently implemented.");
        break;

      case SK_USE_MAGIC_ITEM:
      case SK_MISSILE_WEAPON:
        new_draw_info (NDI_UNIQUE, 0, op, "There is no special attack for this skill.");
        break;

      case SK_PRAYING:
        success = pray (op, skill);
        break;

      case SK_BARGAINING:
        success = describe_shop (op);
        break;

      case SK_SORCERY:
      case SK_EVOCATION:
      case SK_PYROMANCY:
      case SK_SUMMONING:
      case SK_CLIMBING:
        new_draw_info (NDI_UNIQUE, 0, op, "This skill is already in effect.");
        break;

      default:
        LOG (llevDebug, "%s attempted to use unknown skill: %d\n", query_name (op), op->chosen_skill->stats.sp);
        break;
    }

  /* For players we now update the speed_left from using the skill. 
   * Monsters have no skill use time because of the random nature in 
   * which use_monster_skill is called already simulates this.
   * If certain skills should take more/less time, that should be
   * in the code for the skill itself.
   */

  if (op->type == PLAYER)
    op->speed_left -= 1.0;

  /* this is a good place to add experience for successfull use of skills.
   * Note that add_exp() will figure out player/monster experience
   * gain problems.
   */

  if (success && exp)
    change_exp (op, exp, skill->skill, 0);

  return success;
}

/* calc_skill_exp() - calculates amount of experience can be gained for
 * successfull use of a skill.  Returns value of experience gain.
 * Here we take the view that a player must 'overcome an opponent'
 * in order to gain experience. Examples include foes killed combat,
 * finding/disarming a trap, stealing from somebeing, etc.
 * The gained experience is based primarily on the difference in levels,
 * exp point value of vanquished foe, the relevent stats of the skill being
 * used and modifications in the skills[] table.
 *
 * For now, monsters and players will be treated differently. Below I give
 * the algorithm for *PLAYER* experience gain. Monster exp gain is simpler.
 * Monsters just get 10% of the exp of the opponent.
 *
 * players get a ratio, eg, opponent lvl / player level.  This is then
 * multiplied by various things.  If simple exp is true, then
 * this multiplier, include the level difference, is always 1.
 * This revised method prevents some cases where there are big gaps
 * in the amount you get just because you are now equal level vs lower
 * level
 * who is player/creature that used the skill.
 * op is the object that was 'defeated'.
 * skill is the skill used.  If no skill is used, it should just
 * point back to who.
 *
 */
int
calc_skill_exp (object *who, object *op, object *skill)
{
  int op_exp = 0, op_lvl = 0;
  float base, value, lvl_mult = 0.0;

  if (!skill)
    skill = who;

  /* Oct 95 - where we have an object, I expanded our treatment
   * to 3 cases:
   * non-living magic obj, runes and everything else.
   *
   * If an object is not alive and magical we set the base exp higher to
   * help out exp awards for skill_ident skills. Also, if
   * an item is type RUNE, we give out exp based on stats.Cha
   * and level (this was the old system) -b.t. 
   */

  if (!op)
    {                           /* no item/creature */
      op_lvl = who->map->difficulty < 1 ? 1 : who->map->difficulty;
      op_exp = 0;
    }
  else if (op->type == RUNE || op->type == TRAP)
    {                           /* all traps. If stats.Cha > 1 we use that
                                 * for the amount of experience */
      op_exp = op->stats.Cha > 1 ? op->stats.Cha : op->stats.exp;
      op_lvl = op->level;
    }
  else
    {                           /* all other items/living creatures */
      op_exp = op->stats.exp;
      op_lvl = op->level;
      if (!QUERY_FLAG (op, FLAG_ALIVE))
        {                       /* for ident/make items */
          op_lvl += 5 * abs (op->magic);
        }
    }

  if (op_lvl < 1)
    op_lvl = 1;

  if (who->type != PLAYER)
    {                           /* for monsters only */
      return ((int) (op_exp * 0.1) + 1);        /* we add one to insure positive value is returned */
    }
  else
    {                           /* for players */
      base = op_exp;
      /* if skill really is a skill, then we can look at the skill archetype for
       * bse reward value (exp) and level multiplier factor.
       */
      if (skill->type == SKILL)
        {
          base += skill->arch->clone.stats.exp;
          if (settings.simple_exp)
            {
              if (skill->arch->clone.level)
                lvl_mult = (float) skill->arch->clone.level / 100.0;
              else
                lvl_mult = 1.0; /* no adjustment */
            }
          else
            {
              if (skill->level)
                lvl_mult = ((float) skill->arch->clone.level * (float) op_lvl) / ((float) skill->level * 100.0);
              else
                lvl_mult = 1.0;
            }
        }
      else
        {
          /* Don't divide by zero here! */
          lvl_mult = (float) op_lvl / (float) (skill->level ? skill->level : 1);
        }
    }

  /* assemble the exp total, and return value */

  value = base * lvl_mult;
  if (value < 1)
    value = 1;                  /* Always give at least 1 exp point */

#ifdef SKILL_UTIL_DEBUG
  LOG (llevDebug, "calc_skill_exp(): who: %s(lvl:%d)  op:%s(lvl:%d)\n", who->name, skill->level, op->name, op_lvl);
#endif
  return ((int) value);
}

/* Learn skill. This inserts the requested skill in the player's
 * inventory. The skill field of the scroll should have the
 * exact name of the requested skill.
 * This one actually teaches the player the skill as something 
 * they can equip.
 * Return 0 if the player knows the skill, 1 if the
 * player learns the skill, 2 otherwise.
 */
int
learn_skill (object *pl, object *scroll)
{
  object *tmp;

  if (!scroll->skill)
    {
      LOG (llevError, "skill scroll %s does not have skill pointer set.\n", &scroll->name);
      return 2;
    }

  /* can't use find_skill_by_name because we want skills the player knows
   * but can't use natively.
   */

  for (tmp = pl->inv; tmp != NULL; tmp = tmp->below)
    if (tmp->type == SKILL && !strncasecmp (scroll->skill, tmp->skill, strlen (scroll->skill)))
      break;

  /* player already knows it */
  if (tmp && QUERY_FLAG (tmp, FLAG_CAN_USE_SKILL))
    return 0;

  /* now a random change to learn, based on player Int.
   * give bonus based on level - otherwise stupid characters
   * might never be able to learn anything.
   */
  if (random_roll (0, 99, pl, PREFER_LOW) > (learn_spell[pl->stats.Int] + (pl->level / 5)))
    return 2;                   /* failure :< */

  if (!tmp)
    tmp = give_skill_by_name (pl, scroll->skill);

  if (!tmp)
    {
      LOG (llevError, "skill scroll %s does not have valid skill name (%s).\n", &scroll->name, &scroll->skill);
      return 2;
    }

  SET_FLAG (tmp, FLAG_CAN_USE_SKILL);
  link_player_skills (pl);
  return 1;
}

/* Gives a percentage clipped to 0% -> 100% of a/b. */

/* Probably belongs in some global utils-type file? */
static int
clipped_percent (sint64 a, sint64 b)
{
  int rv;

  if (b <= 0)
    return 0;

  rv = (int) ((100.0f * ((float) a) / ((float) b)) + 0.5f);

  if (rv < 0)
    return 0;
  else if (rv > 100)
    return 100;

  return rv;
}

/* show_skills() - Meant to allow players to examine
 * their current skill list.
 * This shows the amount of exp they have in the skills.
 * we also include some other non skill related info (god,
 * max weapon improvments, item power).
 * Note this function is a bit more complicated becauase we
 * we want ot sort the skills before printing them.  If we
 * just dumped this as we found it, this would be a bit
 * simpler.
 */

void
show_skills (object *op, const char *search)
{
  object *tmp = NULL;
  char buf[MAX_BUF];
  const char *cp;
  int i, num_skills_found = 0;
  static const char *const periods = "........................................";

  /* Need to have a pointer and use strdup for qsort to work properly */
  char skills[NUM_SKILLS][MAX_BUF];


  for (tmp = op->inv; tmp != NULL; tmp = tmp->below)
    {
      if (tmp->type == SKILL)
        {
          if (search && strstr (tmp->name, search) == NULL)
            continue;
          /* Basically want to fill this out to 40 spaces with periods */
          sprintf (buf, "%s%s", &tmp->name, periods);
          buf[40] = 0;

          if (settings.permanent_exp_ratio)
            {
              sprintf (skills[num_skills_found++], "%slvl:%3d (xp:%" PRId64 "/%" PRId64 "/%d%%)",
                       buf, tmp->level, tmp->stats.exp,
                       level_exp (tmp->level + 1, op->expmul), clipped_percent (tmp->perm_exp, tmp->stats.exp));
            }
          else
            {
              sprintf (skills[num_skills_found++], "%slvl:%3d (xp:%" PRId64 "/%" PRId64 ")",
                       buf, tmp->level, tmp->stats.exp, level_exp (tmp->level + 1, op->expmul));
            }
          /* I don't know why some characters get a bunch of skills, but
           * it sometimes happens (maybe a leftover from bugier earlier code
           * and those character are still about).  In any case, lets handle
           * it so it doesn't crash the server - otherwise, one character may
           * crash the server numerous times.
           */
          if (num_skills_found >= NUM_SKILLS)
            {
              new_draw_info (NDI_RED, 0, op, "Your character has too many skills.");
              new_draw_info (NDI_RED, 0, op, "Something isn't right - contact the server admin");
              break;
            }
        }
    }

  clear_win_info (op);
  new_draw_info (NDI_UNIQUE, 0, op, "Player skills:");
  if (num_skills_found > 1)
    qsort (skills, num_skills_found, MAX_BUF, (int (*)(const void *, const void *)) std::strcmp);

  for (i = 0; i < num_skills_found; i++)
    new_draw_info (NDI_UNIQUE, 0, op, skills[i]);

  new_draw_info_format (NDI_UNIQUE, 0, op, "You can handle %d weapon improvements.", op->level / 5 + 5);

  cp = determine_god (op);
  new_draw_info_format (NDI_UNIQUE, 0, op, "You worship %s.", cp ? cp : "no god at current time");

  new_draw_info_format (NDI_UNIQUE, 0, op, "Your equipped item power is %d out of %d\n",
                        op->contr->item_power, (int) (op->level * settings.item_power_factor));
}

/* use_skill() - similar to invoke command, it executes the skill in the 
 * direction that the user is facing. Returns false if we are unable to 
 * change to the requested skill, or were unable to use the skill properly.
 * This is tricky because skills can have spaces.  We basically roll 
 * our own find_skill_by_name so we can try to do better string matching.
 */

int
use_skill (object *op, const char *string)
{
  object *skop;
  size_t len;

  if (!string)
    return 0;

  for (skop = op->inv; skop != NULL; skop = skop->below)
    {
      if (skop->type == SKILL && QUERY_FLAG (skop, FLAG_CAN_USE_SKILL) &&
          !strncasecmp (string, skop->skill, MIN (strlen (string), (size_t) strlen (skop->skill))))
        break;
      else if (skop->type == SKILL_TOOL && !strncasecmp (string, skop->skill, MIN (strlen (string), (size_t) strlen (skop->skill))))
        break;
    }
  if (!skop)
    {
      new_draw_info_format (NDI_UNIQUE, 0, op, "Unable to find skill %s", string);
      return 0;
    }

  len = strlen (skop->skill);

  /* All this logic goes and skips over the skill name to find any
   * options given to the skill.  Its pretty simple - if there
   * are extra parameters (as deteremined by string length), we
   * want to skip over any leading spaces.
   */
  if (len >= strlen (string))
    {
      string = NULL;
    }
  else
    {
      string += len;
      while (*string == 0x20)
        string++;
      if (strlen (string) == 0)
        string = NULL;
    }

#ifdef SKILL_UTIL_DEBUG
  LOG (llevDebug, "use_skill() got skill: %s\n", sknum > -1 ? skills[sknum].name : "none");
#endif

  /* Change to the new skill, then execute it. */
  if (do_skill (op, op, skop, op->facing, string))
    return 1;

  return 0;
}

static bool
hth_skill_p (object *skill)
{
  return (skill_flags [skill->subtype] & (SF_COMBAT | SF_NEED_WEAPON)) == SF_COMBAT;
}

/* This finds the first unarmed skill the player has, and returns it.
 */
static object *
find_player_hth_skill (object *op)
{
  for (object *tmp = op->inv; tmp; tmp = tmp->below)
    if (tmp->type == SKILL && QUERY_FLAG (tmp, FLAG_CAN_USE_SKILL) && hth_skill_p (tmp))
      return tmp;

  return 0;
}

/* do_skill_attack() - We have got an appropriate opponent from either
 * move_player_attack() or skill_attack(). In this part we get on with
 * attacking, take care of messages from the attack and changes in invisible.
 * Returns true if the attack damaged the opponent.
 * tmp is the targetted monster.
 * op is what is attacking
 * string is passed along to describe what messages to describe
 * the damage.
 */
static int
do_skill_attack (object *tmp, object *op, const char *string, object *skill)
{
  if (INVOKE_OBJECT (SKILL_ATTACK, op, ARG_OBJECT (tmp), ARG_STRING (string), ARG_OBJECT (skill)))
    return RESULT_INT (0);

  /* For Players only: if there is no ready weapon, and no "attack" skill
   * is readied either then try to find a skill for the player to use.
   * it is presumed that if skill is set, it is a valid attack skill (eg,
   * the caller should have set it appropriately).  We still want to pass
   * through that code if skill is set to change to the skill.
   */
  if (op->type == PLAYER)
    {
      if (!QUERY_FLAG (op, FLAG_READY_WEAPON))
        {
          if (!skill)
            {
              /* See if the players chosen skill is a combat skill, and use
               * it if appropriate.
               */
              if (op->chosen_skill && hth_skill_p (op->chosen_skill))
                skill = op->chosen_skill;
              else
                {
                  skill = find_player_hth_skill (op);

                  if (!skill)
                    {
                      new_draw_info (NDI_BLACK, 0, op, "You have no unarmed combat skills!");
                      return 0;
                    }
                }
            }

          /* now try to ready the new skill */
          if (!change_skill (op, skill, 0))
            {               /* oh oh, trouble! */
              new_draw_info_format (NDI_UNIQUE, 0, tmp, "Couldn't change to skill %s", &skill->name);
              return 0;
            }
        }
      else
        {
          /* Seen some crashes below where current_weapon is not set,
           * even though the flag says it is.  So if current weapon isn't set,
           * do some work in trying to find the object to use.
           */
          if (!op->current_weapon)
            {
              object *tmp;

              LOG (llevError, "Player %s does not have current weapon set but flag_ready_weapon is set\n", &op->name);
              for (tmp = op->inv; tmp; tmp = tmp->below)
                if (tmp->type == WEAPON && QUERY_FLAG (tmp, FLAG_APPLIED))
                  break;

              if (!tmp)
                {
                  LOG (llevError, "Could not find applied weapon on %s\n", &op->name);
                  op->current_weapon = NULL;
                  return 0;
                }
              else
                op->current_weapon = tmp;
            }

          change_skill (op, find_skill_by_name (op, op->current_weapon->skill), 1);
        }
    }

  /* lose invisiblity/hiding status for running attacks */

  if (op->type == PLAYER && op->contr->tmp_invis)
    {
      op->contr->tmp_invis = 0;
      op->invisible = 0;
      op->hide = 0;
      update_object (op, UP_OBJ_CHANGE);
    }

  int success = attack_ob (tmp, op);

  /* print appropriate  messages to the player */

  if (success && string && tmp && !QUERY_FLAG (tmp, FLAG_FREED))
    {
      if (op->type == PLAYER)
        new_draw_info_format (NDI_UNIQUE, 0, op, "You %s %s!", string, query_name (tmp));
      else if (tmp->type == PLAYER)
        new_draw_info_format (NDI_UNIQUE, 0, tmp, "%s %s you!", query_name (op), string);
    }

  return success;
}

/* skill_attack() - Core routine for use when we attack using a skills
 * system. In essence, this code handles
 * all skill-based attacks, ie hth, missile and melee weapons should be
 * treated here. If an opponent is already supplied by move_player(),
 * we move right onto do_skill_attack(), otherwise we find if an
 * appropriate opponent exists.
 *
 * This is called by move_player() and attack_hth()
 *
 * Initial implementation by -bt thomas@astro.psu.edu
 */
int
skill_attack (object *tmp, object *pl, int dir, const char *string, object *skill)
{
  sint16 tx, ty;
  maptile *m;
  int mflags;

  if (!dir)
    dir = pl->facing;

  tx = freearr_x[dir];
  ty = freearr_y[dir];

  /* If we don't yet have an opponent, find if one exists, and attack.
   * Legal opponents are the same as outlined in move_player_attack()
   */
  if (!tmp)
    {
      m = pl->map;
      tx = pl->x + freearr_x[dir];
      ty = pl->y + freearr_y[dir];

      mflags = get_map_flags (m, &m, tx, ty, &tx, &ty);
      if (mflags & P_OUT_OF_MAP)
        return 0;

      /* space must be blocked for there to be anything interesting to do */
      if (!OB_TYPE_MOVE_BLOCK (pl, GET_MAP_MOVE_BLOCK (m, tx, ty)))
        return 0;

      for (tmp = GET_MAP_OB (m, tx, ty); tmp; tmp = tmp->above)
        if ((QUERY_FLAG (tmp, FLAG_ALIVE) && tmp->stats.hp >= 0) || QUERY_FLAG (tmp, FLAG_CAN_ROLL) || tmp->type == LOCKED_DOOR)
          {
            /* Don't attack party members */
            if ((pl->type == PLAYER && tmp->type == PLAYER) && (pl->contr->party != NULL && pl->contr->party == tmp->contr->party))
              return 0;

            break;
          }
    }

  if (!tmp)
    {
      if (pl->type == PLAYER)
        new_draw_info (NDI_UNIQUE, 0, pl, "There is nothing to attack!");

      return 0;
    }

  return do_skill_attack (tmp, pl, string, skill);
}


/* attack_hth() - this handles all hand-to-hand attacks -b.t. */

/* July 5, 1995 - I broke up attack_hth() into 2 parts. In the first
 * (attack_hth) we check for weapon use, etc in the second (the new
 * function skill_attack() we actually attack.
 */

static int
attack_hth (object *pl, int dir, const char *string, object *skill)
{
  object *enemy = NULL, *weapon;

  if (QUERY_FLAG (pl, FLAG_READY_WEAPON))
    for (weapon = pl->inv; weapon; weapon = weapon->below)
      {
        if (weapon->type == WEAPON && QUERY_FLAG (weapon, FLAG_APPLIED))
          {
            CLEAR_FLAG (weapon, FLAG_APPLIED);
            CLEAR_FLAG (pl, FLAG_READY_WEAPON);
            pl->update_stats ();
            if (pl->type == PLAYER)
              {
                new_draw_info (NDI_UNIQUE, 0, pl, "You unwield your weapon in order to attack.");
                esrv_update_item (UPD_FLAGS, pl, weapon);
              }
            break;
          }
      }

  return skill_attack (enemy, pl, dir, string, skill);
}

/* attack_melee_weapon() - this handles melee weapon attacks -b.t.
 * For now we are just checking to see if we have a ready weapon here.
 * But there is a real neato possible feature of this scheme which
 * bears mentioning:
 * Since we are only calling this from do_skill() in the future
 * we may make this routine handle 'special' melee weapons attacks
 * (like disarming manuever with sai) based on player SK_level and
 * weapon type.
 */
static int
attack_melee_weapon (object *op, int dir, const char *string, object *skill)
{

  if (!QUERY_FLAG (op, FLAG_READY_WEAPON))
    {
      if (op->type == PLAYER)
        new_draw_info (NDI_UNIQUE, 0, op, "You have no ready weapon to attack with!");

      return 0;
    }

  return skill_attack (NULL, op, dir, string, skill);

}
Revision:	1.34
Committed:	Mon Apr 30 05:54:14 2007 UTC (17 years ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.33:	+7 -7 lines
Log Message:	works a tad better