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] = {
# 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;

  if (who->chosen_skill && who->chosen_skill == new_skill)
    {
      //who->contr->combat_skill = who->chosen_skill;
      return 1;
    }

  if (!new_skill)
    {
      if (who->chosen_skill)
        apply_special (who, who->chosen_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:	1.33
Committed:	Mon Apr 30 04:25:30 2007 UTC (17 years, 1 month ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.32:	+27 -50 lines
Log Message:	This is the first rough cut of the skill use system (use the STABLE tag). Details will likely change, and combat skills do not work very well, but it works quite well. Players no longer have a shoottype or range slots, instead, each player has these members: combat_skill/combat_ob the currently selected skill (and weapon) for direct attacks. ranged_skill/ranged_ob the currently selected ranged skill (and bow/spell/item) golem the currently-controlled golem, if any.