src/tile/zoneheight.h

   1 /*
   2  * This file is part of OpenTTD.
   3  * OpenTTD 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, version 2.
   4  * OpenTTD 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.
   5  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   6  */
   7
   8 /** @file tile/zoneheight.h Types related to tile zone and height. */
   9
  10 #ifndef TILE_ZONEHEIGHT_H
  11 #define TILE_ZONEHEIGHT_H
  12
  13 #include "../stdafx.h"
  14 #include "../core/bitmath_func.hpp"
  15
  16 static const uint MAX_TILE_HEIGHT     = 15;                    ///< Maximum allowed tile height
  17
  18 static const uint MIN_SNOWLINE_HEIGHT = 2;                     ///< Minimum snowline height
  19 static const uint DEF_SNOWLINE_HEIGHT = 7;                     ///< Default snowline height
  20 static const uint MAX_SNOWLINE_HEIGHT = (MAX_TILE_HEIGHT - 2); ///< Maximum allowed snowline height
  21
  22 /**
  23  * Tropic zone of a tile (subtropic climate only).
  24  *
  25  * The tropiczone is not modified during gameplay. It mainly affects tree growth (desert tiles are visible though).
  26  *
  27  * In randomly generated maps:
  28  *  TROPICZONE_DESERT: Generated everywhere, if there is neither water nor mountains (TileHeight >= 4) in a certain distance from the tile.
  29  *  TROPICZONE_RAINFOREST: Generated everywhere, if there is no desert in a certain distance from the tile.
  30  *  TROPICZONE_NORMAL: Everywhere else, i.e. between desert and rainforest and on sea (if you clear the water).
  31  *
  32  * In scenarios:
  33  *  TROPICZONE_NORMAL: Default value.
  34  *  TROPICZONE_DESERT: Placed manually.
  35  *  TROPICZONE_RAINFOREST: Placed if you plant certain rainforest-trees.
  36  */
  37 enum TropicZone {
  38         TROPICZONE_NORMAL     = 0,      ///< Normal tropiczone
  39         TROPICZONE_DESERT     = 1,      ///< Tile is desert
  40         TROPICZONE_RAINFOREST = 2,      ///< Rainforest tile
  41 };
  42
  43 /**
  44  * Zone and height of a tile.
  45  * The zone goes into the 2 most significant bits; the height goes into
  46  * the 4 least significant bits.
  47  */
  48 typedef byte TileZH;
  49
  50 /**
  51  * Get the height of a tile
  52  *
  53  * This function returns the height of the northern corner of a tile.
  54  *
  55  * @param t The tile whose height to get
  56  * @return The height of the tile
  57  */
  58 static inline uint tilezh_get_height(const TileZH *t)
  59 {
  60         return GB(*t, 0, 4);
  61 }
  62
  63 /**
  64  * Set the height of a tile
  65  *
  66  * This function sets the height of the northern corner of a tile.
  67  *
  68  * @param t The tile whose height to set
  69  * @param height The new height value of the tile
  70  * @pre height <= MAX_TILE_HEIGHT
  71  */
  72 static inline void tilezh_set_height(TileZH *t, uint height)
  73 {
  74         assert(height <= MAX_TILE_HEIGHT);
  75         SB(*t, 0, 4, height);
  76 }
  77
  78 /**
  79  * Get the tropic zone of a tile
  80  * @param t The tile whose zone to get
  81  * @return The zone type of the tile
  82  */
  83 static inline TropicZone tilezh_get_zone(const TileZH *t)
  84 {
  85         return (TropicZone)GB(*t, 6, 2);
  86 }
  87
  88 /**
  89  * Set the tropic zone of a tile
  90  * @param t The tile whose zone to set
  91  * @param z The new zone type
  92  * @pre tile < MapSize()
  93  */
  94 static inline void tilezh_set_zone(TileZH *t, TropicZone z)
  95 {
  96         SB(*t, 6, 2, z);
  97 }
  98
  99 #endif /* TILE_ZONEHEIGHT_H */