advgoto.c

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/***********************************************************************
 Freeciv - Copyright (C) 1996 - A Kjeldberg, L Gregersen, P Unold
   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, 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.
***********************************************************************/
 
#ifdef HAVE_CONFIG_H
#include <fc_config.h>
#endif
 
/* common */
#include "ai.h"
#include "combat.h"
#include "game.h"
#include "movement.h"
#include "unit.h"
#include "tile.h"
 
/* aicore */
#include "path_finding.h"
 
/* server */
#include "maphand.h"
#include "srv_log.h"
#include "unithand.h"
#include "unittools.h"
 
/* server/advisors */
#include "advtools.h"
 
#include "advgoto.h"
 
static bool adv_unit_move(struct unit *punit, struct tile *ptile);
 
/**********************************************************************/
bool adv_follow_path(struct unit *punit, struct pf_path *path,
                     struct tile *ptile)
{
  struct tile *old_tile = punit->goto_tile;
  enum unit_activity activity = punit->activity;
  struct extra_type *tgt = punit->activity_target;
  bool alive;
 
  if (punit->moves_left <= 0) {
    return TRUE;
  }
 
  punit->goto_tile = ptile;
  unit_activity_handling(punit, ACTIVITY_GOTO, ACTION_NONE);
  alive = adv_unit_execute_path(punit, path);
 
  if (alive) {
    if (activity != ACTIVITY_GOTO) {
      /* Only go via ACTIVITY_IDLE if we are actually changing the activity */
      unit_activity_handling(punit, ACTIVITY_IDLE, ACTION_NONE);
      send_unit_info(NULL, punit); /* FIXME: probably duplicate */
      unit_activity_handling_targeted(punit, activity, &tgt,
                                      activity_default_action(activity));
    }
    punit->goto_tile = old_tile; /* May be NULL. */
    send_unit_info(NULL, punit);
  }
 
  return alive;
}
 
 
/**********************************************************************/
bool adv_unit_execute_path(struct unit *punit, struct pf_path *path)
{
  const bool is_plr_ai = is_ai(unit_owner(punit));
  int i;
 
  /* We start with i = 1 for i = 0 is our present position */
  for (i = 1; i < path->length; i++) {
    struct tile *ptile = path->positions[i].tile;
    int id = punit->id;
 
    if (same_pos(unit_tile(punit), ptile)) {
#ifdef PF_WAIT_DEBUG
      fc_assert_msg(
#if PF_WAIT_DEBUG & 1
                    punit->moves_left < unit_move_rate(punit)
#if PF_WAIT_DEBUG & (2 | 4)
                   ||
#endif
#endif
#if PF_WAIT_DEBUG & 2
                   punit->fuel < utype_fuel(unit_type_get(punit))
#if PF_WAIT_DEBUG & 4
                   ||
#endif
#endif
#if PF_WAIT_DEBUG & 4
                   punit->hp < unit_type_get(punit)->hp
#endif
                    , "%s waits at %d,%d for no visible profit",
                    unit_rule_name(punit), TILE_XY(ptile));
#endif
      UNIT_LOG(LOG_DEBUG, punit, "execute_path: waiting this turn");
      return TRUE;
    }
 
    /* We use ai_unit_move() for everything but the last step
     * of the way so that we abort if unexpected opposition
     * shows up. Any enemy on the target tile is expected to
     * be our target and any attack there intentional.
     * However, do not annoy human players by automatically attacking
     * using units temporarily under AI control (such as auto-explorers)
     */
 
    if (is_plr_ai) {
      CALL_PLR_AI_FUNC(unit_move, unit_owner(punit), punit, ptile, path, i);
    } else {
      (void) adv_unit_move(punit, ptile);
    }
    if (!game_unit_by_number(id)) {
      /* Died... */
      return FALSE;
    }
 
    if (!same_pos(unit_tile(punit), ptile) || punit->moves_left <= 0) {
      /* Stopped (or maybe fought) or ran out of moves */
      return TRUE;
    }
  }
 
  return TRUE;
}
 
/**********************************************************************/
static bool adv_unit_move(struct unit *punit, struct tile *ptile)
{
  struct action *paction;
  struct player *pplayer = unit_owner(punit);
  struct unit *ptrans = NULL;
  const struct civ_map *nmap = &(wld.map);
 
  /* If enemy, stop and give a chance for the human player to
     handle this case */
  if (is_enemy_unit_tile(ptile, pplayer)
      || is_enemy_city_tile(ptile, pplayer)) {
    UNIT_LOG(LOG_DEBUG, punit, "movement halted due to enemy presence");
    return FALSE;
  }
 
  /* Select move kind. */
  if (!can_unit_survive_at_tile(nmap, punit, ptile)
      && ((ptrans = transporter_for_unit_at(punit, ptile)))
      && is_action_enabled_unit_on_unit(nmap, ACTION_TRANSPORT_EMBARK,
                                        punit, ptrans)) {
    /* "Transport Embark". */
    paction = action_by_number(ACTION_TRANSPORT_EMBARK);
  } else if (!can_unit_survive_at_tile(nmap, punit, ptile)
             && ptrans != NULL
             && is_action_enabled_unit_on_unit(nmap, ACTION_TRANSPORT_EMBARK2,
                                               punit, ptrans)) {
    /* "Transport Embark 2". */
    paction = action_by_number(ACTION_TRANSPORT_EMBARK2);
  } else if (!can_unit_survive_at_tile(nmap, punit, ptile)
             && ptrans != NULL
             && is_action_enabled_unit_on_unit(nmap, ACTION_TRANSPORT_EMBARK3,
                                               punit, ptrans)) {
    /* "Transport Embark 3". */
    paction = action_by_number(ACTION_TRANSPORT_EMBARK3);
  } else if (!can_unit_survive_at_tile(nmap, punit, ptile)
             && ptrans != NULL
             && is_action_enabled_unit_on_unit(nmap, ACTION_TRANSPORT_EMBARK4,
                                               punit, ptrans)) {
    /* "Transport Embark 4". */
    paction = action_by_number(ACTION_TRANSPORT_EMBARK4);
  } else if (is_action_enabled_unit_on_tile(nmap, ACTION_TRANSPORT_DISEMBARK1,
                                            punit, ptile, NULL)) {
    /* "Transport Disembark". */
    paction = action_by_number(ACTION_TRANSPORT_DISEMBARK1);
  } else if (is_action_enabled_unit_on_tile(nmap, ACTION_TRANSPORT_DISEMBARK2,
                                            punit, ptile, NULL)) {
    /* "Transport Disembark 2". */
    paction = action_by_number(ACTION_TRANSPORT_DISEMBARK2);
  } else if (is_action_enabled_unit_on_tile(nmap, ACTION_TRANSPORT_DISEMBARK3,
                                            punit, ptile, NULL)) {
    /* "Transport Disembark 3". */
    paction = action_by_number(ACTION_TRANSPORT_DISEMBARK3);
  } else if (is_action_enabled_unit_on_tile(nmap, ACTION_TRANSPORT_DISEMBARK4,
                                            punit, ptile, NULL)) {
    /* "Transport Disembark 4". */
    paction = action_by_number(ACTION_TRANSPORT_DISEMBARK4);
  } else if (is_action_enabled_unit_on_tile(nmap, ACTION_HUT_ENTER,
                                            punit, ptile, NULL)) {
    /* "Enter Hut". */
    paction = action_by_number(ACTION_HUT_ENTER);
  } else if (is_action_enabled_unit_on_tile(nmap, ACTION_HUT_ENTER2,
                                            punit, ptile, NULL)) {
    /* "Enter Hut 2". */
    paction = action_by_number(ACTION_HUT_ENTER2);
  } else if (is_action_enabled_unit_on_tile(nmap, ACTION_HUT_ENTER3,
                                            punit, ptile, NULL)) {
    /* "Enter Hut 3". */
    paction = action_by_number(ACTION_HUT_ENTER3);
  } else if (is_action_enabled_unit_on_tile(nmap, ACTION_HUT_ENTER4,
                                            punit, ptile, NULL)) {
    /* "Enter Hut 4". */
    paction = action_by_number(ACTION_HUT_ENTER4);
  } else if (is_action_enabled_unit_on_tile(nmap, ACTION_HUT_FRIGHTEN,
                                            punit, ptile, NULL)) {
    /* "Frighten Hut". */
    paction = action_by_number(ACTION_HUT_FRIGHTEN);
  } else if (is_action_enabled_unit_on_tile(nmap, ACTION_HUT_FRIGHTEN2,
                                            punit, ptile, NULL)) {
    /* "Frighten Hut 2". */
    paction = action_by_number(ACTION_HUT_FRIGHTEN2);
  } else if (is_action_enabled_unit_on_tile(nmap, ACTION_HUT_FRIGHTEN3,
                                            punit, ptile, NULL)) {
    /* "Frighten Hut 3". */
    paction = action_by_number(ACTION_HUT_FRIGHTEN3);
  } else if (is_action_enabled_unit_on_tile(nmap, ACTION_HUT_FRIGHTEN4,
                                            punit, ptile, NULL)) {
    /* "Frighten Hut 4". */
    paction = action_by_number(ACTION_HUT_FRIGHTEN4);
  } else if (is_action_enabled_unit_on_tile(nmap, ACTION_UNIT_MOVE,
                                            punit, ptile, NULL)) {
    /* "Unit Move". */
    paction = action_by_number(ACTION_UNIT_MOVE);
  } else if (is_action_enabled_unit_on_tile(nmap, ACTION_UNIT_MOVE2,
                                            punit, ptile, NULL)) {
    /* "Unit Move 2". */
    paction = action_by_number(ACTION_UNIT_MOVE2);
  } else {
    /* "Unit Move 3". */
    paction = action_by_number(ACTION_UNIT_MOVE3);
  }
 
  /* Try not to end move next to an enemy if we can avoid it by waiting */
  if (action_has_result(paction, ACTRES_UNIT_MOVE)
      || action_has_result(paction, ACTRES_TRANSPORT_DISEMBARK)) {
    /* The unit will have to move it self rather than being moved. */
    int mcost = map_move_cost_unit(nmap, punit, ptile);
 
    if (paction) {
      struct tile *from_tile;
 
      /* Ugly hack to understand the OnNativeTile unit state requirements
       * used in the Action_Success_Actor_Move_Cost effect. */
      fc_assert(utype_is_moved_to_tgt_by_action(paction,
                                                unit_type_get(punit)));
      from_tile = unit_tile(punit);
      punit->tile = ptile;
 
      mcost += unit_pays_mp_for_action(paction, punit);
 
      punit->tile = from_tile;
    }
 
    if (punit->moves_left <= mcost
        && unit_move_rate(punit) > mcost
        && adv_danger_at(punit, ptile)
        && !adv_danger_at(punit, unit_tile(punit))) {
      UNIT_LOG(LOG_DEBUG, punit,
               "ending move early to stay out of trouble");
      return FALSE;
    }
  }
 
  /* Go */
  unit_activity_handling(punit, ACTIVITY_IDLE, ACTION_NONE);
  /* Move */
  /* TODO: Differentiate (server side AI) player from server side agent
   * working for (possibly AI) player by using ACT_REQ_PLAYER and
   * ACT_REQ_SS_AGENT */
  if (paction != nullptr && ptrans != nullptr
      && action_has_result(paction, ACTRES_TRANSPORT_EMBARK)) {
      /* "Transport Embark". */
      unit_do_action(unit_owner(punit), punit->id, ptrans->id,
                     0, "", action_number(paction));
    } else if (paction
               && (action_has_result(paction,
                                     ACTRES_TRANSPORT_DISEMBARK)
                   || action_has_result(paction,
                                        ACTRES_HUT_ENTER)
                   || action_has_result(paction,
                                        ACTRES_HUT_FRIGHTEN)
                   || action_has_result(paction,
                                        ACTRES_UNIT_MOVE))) {
    /* "Transport Disembark", "Transport Disembark 2", "Enter Hut",
     * "Frighten Hut" or "Unit Move". */
    unit_do_action(unit_owner(punit), punit->id, tile_index(ptile),
                   0, "", action_number(paction));
  }
 
  return TRUE;
}
 
/**********************************************************************/
static bool adv_could_be_my_zoc(struct unit *punit, struct tile *ptile)
{
  struct tile *utile = unit_tile(punit);
  struct player *owner;
  struct civ_map *cmap = &(wld.map);
  bool flagless = unit_has_type_flag(punit, UTYF_FLAGLESS);
 
  if (same_pos(ptile, utile)) {
    return FALSE; /* Can't be my zoc */
  }
 
  owner = unit_owner(punit);
  if (is_tiles_adjacent(ptile, utile)
      && !is_non_allied_unit_tile(ptile, owner, flagless)) {
    return FALSE;
  }
 
  adjc_iterate(cmap, ptile, atile) {
    if (!terrain_has_flag(tile_terrain(atile), TER_NO_ZOC)
        && is_non_allied_unit_tile(atile, owner, flagless)) {
      return FALSE;
    }
  } adjc_iterate_end;
 
  return TRUE;
}
 
/**********************************************************************/
int adv_could_unit_move_to_tile(struct unit *punit, struct tile *dest_tile)
{
  enum unit_move_result reason =
    unit_move_to_tile_test(&(wld.map), punit, ACTIVITY_IDLE, unit_tile(punit),
                           dest_tile, unit_has_type_flag(punit, UTYF_IGZOC),
                           TRUE, NULL, FALSE);
 
  switch (reason) {
  case MR_OK:
    return 1;
 
  case MR_ZOC:
    if (adv_could_be_my_zoc(punit, unit_tile(punit))) {
      return -1;
    }
    break;
 
  default:
    break;
  };
  return 0;
}
 
/**********************************************************************/
int adv_unittype_att_rating(const struct unit_type *punittype, int veteran,
                            int moves_left, int hp)
{
  return base_get_attack_power(punittype, veteran, moves_left) * hp
         * punittype->firepower / POWER_DIVIDER;
}
 
/**********************************************************************/
int adv_unit_att_rating(const struct unit *punit)
{
  return adv_unittype_att_rating(unit_type_get(punit), punit->veteran,
                                 SINGLE_MOVE, punit->hp);
}
 
/**********************************************************************/
int adv_unit_def_rating_basic(const struct unit *punit)
{
  return base_get_defense_power(punit) * punit->hp *
    unit_type_get(punit)->firepower / POWER_DIVIDER;
}
 
/**********************************************************************/
int adv_unit_def_rating_basic_squared(const struct unit *punit)
{
  int v = adv_unit_def_rating_basic(punit);
 
  return v * v;
}
 
/**********************************************************************/
bool adv_danger_at(struct unit *punit, struct tile *ptile)
{
  int a = 0, d, db;
  struct player *pplayer = unit_owner(punit);
  struct city *pcity = tile_city(ptile);
  enum override_bool dc = NO_OVERRIDE;
  int extras_bonus = 0;
  struct player *owner = unit_owner(punit);
 
  /* Give AI code possibility to decide itself */
  CALL_PLR_AI_FUNC(consider_tile_dangerous, owner, ptile, punit, &dc);
  if (dc == OVERRIDE_TRUE) {
    return TRUE;
  } else if (dc == OVERRIDE_FALSE) {
    return FALSE;
  }
 
  if (pcity != NULL && pplayers_allied(city_owner(pcity), owner)
      && !is_non_allied_unit_tile(ptile, pplayer,
                                  unit_has_type_flag(punit, UTYF_FLAGLESS))) {
    /* We will be safe in a friendly city */
    return FALSE;
  }
 
  /* Calculate how well we can defend at (x,y) */
  db = 10 + tile_terrain(ptile)->defense_bonus / 10;
  extras_bonus += tile_extras_defense_bonus(ptile, unit_type_get(punit));
  db += (db * extras_bonus) / 100;
  d = adv_unit_def_rating_basic_squared(punit) * db;
 
  adjc_iterate(&(wld.map), ptile, ptile1) {
    if (!map_is_known_and_seen(ptile1, owner, V_MAIN)) {
      /* We cannot see danger at (ptile1) => assume there is none */
      continue;
    }
    unit_list_iterate(ptile1->units, enemy) {
      if (pplayers_at_war(unit_owner(enemy), owner)
          && (unit_attack_unit_at_tile_result(enemy, NULL, punit, ptile)
              == ATT_OK)
          && (unit_attack_units_at_tile_result(enemy, NULL, ptile)
              == ATT_OK)) {
        a += adv_unit_att_rating(enemy);
        if ((a * a * 10) >= d) {
          /* The enemies combined strength is too big! */
          return TRUE;
        }
      }
    } unit_list_iterate_end;
  } adjc_iterate_end;
 
  return FALSE; /* As good a quick'n'dirty should be -- Syela */
}
 
/**********************************************************************/
static int stack_value(const struct tile *ptile,
                       const struct player *pplayer)
{
  int cost = 0;
 
  if (is_stack_vulnerable(ptile)) {
    unit_list_iterate(ptile->units, punit) {
      if (unit_owner(punit) == pplayer) {
        cost += unit_build_shield_cost_base(punit);
      }
    } unit_list_iterate_end;
  }
 
  return cost;
}
 
/**********************************************************************/
static double chance_killed_at(const struct tile *ptile,
                               struct adv_risk_cost *risk_cost,
                               const struct pf_parameter *param)
{
  double db;
  int extras_bonus = 0;
  /* Compute the basic probability */
  /* WAG */
  /* In the early stages of a typical game, ferries
   * are effectively invulnerable (not until Frigates set sail),
   * so we make seas appear safer.
   * If we don't do this, the amphibious movement code has too strong a
   * desire to minimise the length of the path,
   * leading to poor choice for landing beaches */
  double p = is_ocean_tile(ptile)? 0.05: 0.15;
 
  /* If we are on defensive terrain, we are more likely to survive */
  db = 10 + tile_terrain(ptile)->defense_bonus / 10;
  extras_bonus += tile_extras_class_defense_bonus(ptile,
                                                  utype_class(param->utype));
  db += (extras_bonus) / 100;
  p *= 10.0 / db;
 
  return p;
}
 
/**********************************************************************/
static unsigned stack_risk(const struct tile *ptile,
                           struct adv_risk_cost *risk_cost,
                           const struct pf_parameter *param)
{
  double risk = 0;
  /* Compute the risk of destruction, assuming we will stop at this tile */
  const double value = risk_cost->base_value
                       + stack_value(ptile, param->owner);
  const double p_killed = chance_killed_at(ptile, risk_cost, param);
  double danger = value * p_killed;
 
  /* Adjust for the fact that we might not stop at this tile,
   * and for our fearfulness */
  risk += danger * risk_cost->fearfulness;
 
  /* Adjust for the risk that we might become stuck (for an indefinite period)
   * if we enter or try to enter the tile. */
  if (risk_cost->enemy_zoc_cost != 0
      && (is_non_allied_city_tile(ptile, param->owner)
          || !is_plr_zoc_srv(param->owner, ptile, param->map)
          || is_non_allied_unit_tile(ptile, param->owner,
                                     utype_has_flag(param->utype, UTYF_FLAGLESS)))) {
    /* We could become stuck. */
    risk += risk_cost->enemy_zoc_cost;
  }
 
  return risk;
}
 
/**********************************************************************/
static unsigned prefer_short_stacks(const struct tile *ptile,
                                    enum known_type known,
                                    const struct pf_parameter *param)
{
  return stack_risk(ptile, (struct adv_risk_cost *)param->data, param);
}
 
/**********************************************************************/
void adv_avoid_risks(struct pf_parameter *parameter,
                     struct adv_risk_cost *risk_cost,
                     struct unit *punit,
                     const double fearfulness)
{
  /* If we stay a short time on each tile, the danger of each individual tile
   * is reduced. If we do not do this,
   * we will not favour longer but faster routs. */
  const double linger_fraction = (double)SINGLE_MOVE / parameter->move_rate;
 
  parameter->data = risk_cost;
  parameter->get_EC = prefer_short_stacks;
  risk_cost->base_value = unit_build_shield_cost_base(punit);
  risk_cost->fearfulness = fearfulness * linger_fraction;
 
  risk_cost->enemy_zoc_cost = PF_TURN_FACTOR * 20;
}