common/borders.c

   1 /****************************************************************************
   2  Freeciv - Copyright (C) 2004 - The Freeciv Team
   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 "fcintl.h"
  20 #include "log.h"
  21
  22 /* common */
  23 #include "game.h"
  24 #include "map.h"
  25 #include "tile.h"
  26 #include "unit.h"
  27
  28 #include "borders.h"
  29
  30 /*************************************************************************
  31   Border radius sq from given border source tile.
  32 *************************************************************************/
  33 int tile_border_source_radius_sq(struct tile *ptile)
  34 {
  35   struct city *pcity;
  36   int radius_sq = 0;
  37
  38   if (BORDERS_DISABLED == game.info.borders) {
  39     return 0;
  40   }
  41
  42   pcity = tile_city(ptile);
  43
  44   if (pcity) {
  45     radius_sq = game.info.border_city_radius_sq;
  46     /* Limit the addition due to the city size. A city size of 60 or more is
  47      * possible with a city radius of 5 (radius_sq = 26). */
  48     radius_sq += MIN(city_size_get(pcity), CITY_MAP_MAX_RADIUS_SQ)
  49                  * game.info.border_size_effect;
  50   } else {
  51     extra_type_by_cause_iterate(EC_BASE, pextra) {
  52       struct base_type *pbase = extra_base_get(pextra);
  53
  54       if (tile_has_extra(ptile, pextra) && territory_claiming_base(pbase)) {
  55         radius_sq = pbase->border_sq;
  56         break;
  57       }
  58     } extra_type_by_cause_iterate_end;
  59   }
  60
  61   return radius_sq;
  62 }
  63
  64 /*************************************************************************
  65   Border source strength
  66 *************************************************************************/
  67 int tile_border_source_strength(struct tile *ptile)
  68 {
  69   struct city *pcity;
  70   int strength = 0;
  71
  72   if (BORDERS_DISABLED == game.info.borders) {
  73     return 0;
  74   }
  75
  76   pcity = tile_city(ptile);
  77
  78   if (pcity) {
  79     strength = city_size_get(pcity) + 2;
  80   } else {
  81     extra_type_by_cause_iterate(EC_BASE, pextra) {
  82       struct base_type *pbase = extra_base_get(pextra);
  83
  84       if (tile_has_extra(ptile, pextra) && territory_claiming_base(pbase)) {
  85         strength = 1;
  86         break;
  87       }
  88     } extra_type_by_cause_iterate_end;
  89   }
  90
  91   return strength;
  92 }
  93
  94 /*************************************************************************
  95   Border source strength at tile
  96 *************************************************************************/
  97 int tile_border_strength(struct tile *ptile, struct tile *source)
  98 {
  99   int full_strength = tile_border_source_strength(source);
 100   int sq_dist = sq_map_distance(ptile, source);
 101
 102   if (sq_dist > 0) {
 103     return full_strength * full_strength / sq_dist;
 104   } else {
 105     return FC_INFINITY;
 106   }
 107 }
 108
 109 /*************************************************************************
 110   Is given tile source to borders.
 111 *************************************************************************/
 112 bool is_border_source(struct tile *ptile)
 113 {
 114   if (tile_city(ptile)) {
 115     return TRUE;
 116   }
 117
 118   if (extra_owner(ptile) != NULL) {
 119     extra_type_by_cause_iterate(EC_BASE, pextra) {
 120       struct base_type *pbase = extra_base_get(pextra);
 121
 122       if (tile_has_extra(ptile, pextra) && territory_claiming_base(pbase)) {
 123         return TRUE;
 124       }
 125     } extra_type_by_cause_iterate_end;
 126   }
 127
 128   return FALSE;
 129 }