common/aicore/aisupport.c

   1 /**********************************************************************
   2  Freeciv - Copyright (C) 2003 - The Freeciv Project
   3    This program is free software; you can redistribute it and/or modify
   4    it under the terms of the GNU General Public License as published by
   5    the Free Software Foundation; either version 2, or (at your option)
   6    any later version.
   7
   8    This program is distributed in the hope that it will be useful,
   9    but WITHOUT ANY WARRANTY; without even the implied warranty of
  10    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11    GNU General Public License for more details.
  12 ***********************************************************************/
  13
  14 #ifdef HAVE_CONFIG_H
  15 #include <fc_config.h>
  16 #endif
  17
  18 /* utility */
  19 #include "log.h"
  20 #include "shared.h"
  21 #include "support.h"
  22
  23 /* common */
  24 #include "city.h"
  25 #include "game.h"
  26 #include "map.h"
  27 #include "player.h"
  28 #include "spaceship.h"
  29 #include "tech.h"
  30 #include "unitlist.h"
  31 #include "victory.h"
  32
  33 #include "aisupport.h"
  34
  35 /**********************************************************************
  36   Find who is leading the space race. Returns NULL if nobody is.
  37 ***********************************************************************/
  38 struct player *player_leading_spacerace(void)
  39 {
  40   struct player *best = NULL;
  41   int best_arrival = FC_INFINITY;
  42   enum spaceship_state best_state = SSHIP_NONE;
  43
  44   if (!victory_enabled(VC_SPACERACE)) {
  45     return NULL;
  46   }
  47
  48   players_iterate_alive(pplayer) {
  49     struct player_spaceship *ship = &pplayer->spaceship;
  50     int arrival = (int) ship->travel_time + ship->launch_year;
  51
  52     if (is_barbarian(pplayer) || ship->state == SSHIP_NONE) {
  53       continue;
  54     }
  55
  56     if (ship->state != SSHIP_LAUNCHED
  57         && ship->state > best_state) {
  58       best_state = ship->state;
  59       best = pplayer;
  60     } else if (ship->state == SSHIP_LAUNCHED
  61                && arrival < best_arrival) {
  62       best_state = ship->state;
  63       best_arrival = arrival;
  64       best = pplayer;
  65     }
  66   } players_iterate_alive_end;
  67
  68   return best;
  69 }
  70
  71 /**********************************************************************
  72   Calculate average distances to other players. We calculate the
  73   average distance from all of our cities to the closest enemy city.
  74 ***********************************************************************/
  75 int player_distance_to_player(struct player *pplayer, struct player *target)
  76 {
  77   int cities = 0;
  78   int dists = 0;
  79
  80   if (pplayer == target
  81       || !target->is_alive
  82       || !pplayer->is_alive
  83       || city_list_size(pplayer->cities) == 0
  84       || city_list_size(target->cities) == 0) {
  85     return 1;
  86   }
  87
  88   /* For all our cities, find the closest distance to an enemy city. */
  89   city_list_iterate(pplayer->cities, pcity) {
  90     int min_dist = FC_INFINITY;
  91
  92     city_list_iterate(target->cities, c2) {
  93       int dist = real_map_distance(c2->tile, pcity->tile);
  94
  95       if (min_dist > dist) {
  96         min_dist = dist;
  97       }
  98     } city_list_iterate_end;
  99     dists += min_dist;
 100     cities++;
 101   } city_list_iterate_end;
 102
 103   return MAX(dists / cities, 1);
 104 }
 105
 106 /**********************************************************************
 107   Rough calculation of the worth of pcity in gold.
 108 ***********************************************************************/
 109 int city_gold_worth(struct city *pcity)
 110 {
 111   struct player *pplayer = city_owner(pcity);
 112   int worth = 0, i;
 113   struct unit_type *u = NULL;
 114
 115   if (!game.scenario.prevent_new_cities) {
 116     u = best_role_unit_for_player(city_owner(pcity),
 117                                   action_id_get_role(ACTION_FOUND_CITY));
 118   }
 119
 120   if (u != NULL) {
 121     worth += utype_buy_gold_cost(u, 0); /* cost of settler */
 122   }
 123   for (i = 1; i < city_size_get(pcity); i++) {
 124     worth += city_granary_size(i); /* cost of growing city */
 125   }
 126   output_type_iterate(o) {
 127     worth += pcity->prod[o] * 10;
 128   } output_type_iterate_end;
 129   unit_list_iterate(pcity->units_supported, punit) {
 130     if (same_pos(unit_tile(punit), pcity->tile)) {
 131       struct unit_type *punittype = unit_type_get(punit)->obsoleted_by;
 132
 133       if (punittype && can_city_build_unit_direct(pcity, punittype)) {
 134         worth += unit_disband_shields(punit); /* obsolete, candidate for disbanding */
 135       } else {
 136         worth += unit_build_shield_cost(punit); /* good stuff */
 137       }
 138     }
 139   } unit_list_iterate_end;
 140   city_built_iterate(pcity, pimprove) {
 141     if (improvement_obsolete(pplayer, pimprove, pcity)) {
 142       worth += impr_sell_gold(pimprove); /* obsolete, candidate for selling */
 143     } else if (!is_wonder(pimprove)) {
 144       worth += impr_build_shield_cost(pimprove) * 2; /* Buy cost, with nonzero shield amount */
 145     } else {
 146       worth += impr_build_shield_cost(pimprove) * 4;
 147     }
 148   } city_built_iterate_end;
 149   if (city_unhappy(pcity)) {
 150     worth *= 0.75;
 151   }
 152   return worth;
 153 }