src/mg_biome.cpp

   1 /*
   2 Minetest
   3 Copyright (C) 2010-2013 kwolekr, Ryan Kwolek <kwolekr@minetest.net>
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU Lesser General Public License as published by
   7 the Free Software Foundation; either version 2.1 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU Lesser General Public License for more details.
  14
  15 You should have received a copy of the GNU Lesser General Public License along
  16 with this program; if not, write to the Free Software Foundation, Inc.,
  17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #include "mg_biome.h"
  21 #include "gamedef.h"
  22 #include "nodedef.h"
  23 #include "map.h" //for ManualMapVoxelManipulator
  24 #include "log.h"
  25 #include "util/numeric.h"
  26 #include "main.h"
  27 #include "util/mathconstants.h"
  28 #include "porting.h"
  29
  30 const char *BiomeManager::ELEMENT_TITLE = "biome";
  31
  32
  33 ///////////////////////////////////////////////////////////////////////////////
  34
  35 BiomeManager::BiomeManager(IGameDef *gamedef)
  36 {
  37         m_resolver  = gamedef->getNodeDefManager()->getResolver();
  38
  39         // Create default biome to be used in case none exist
  40         Biome *b = new Biome;
  41
  42         b->id             = 0;
  43         b->name           = "Default";
  44         b->flags          = 0;
  45         b->depth_top      = 0;
  46         b->depth_filler   = 0;
  47         b->height_min     = -MAP_GENERATION_LIMIT;
  48         b->height_max     = MAP_GENERATION_LIMIT;
  49         b->heat_point     = 0.0;
  50         b->humidity_point = 0.0;
  51
  52         m_resolver->addNode("air",                 "", CONTENT_AIR, &b->c_top);
  53         m_resolver->addNode("air",                 "", CONTENT_AIR, &b->c_filler);
  54         m_resolver->addNode("mapgen_stone",        "", CONTENT_AIR, &b->c_stone);
  55         m_resolver->addNode("mapgen_water_source", "", CONTENT_AIR, &b->c_water);
  56         m_resolver->addNode("air",                 "", CONTENT_AIR, &b->c_dust);
  57         m_resolver->addNode("mapgen_water_source", "", CONTENT_AIR, &b->c_dust_water);
  58
  59         add(b);
  60 }
  61
  62
  63
  64 BiomeManager::~BiomeManager()
  65 {
  66         //if (biomecache)
  67         //      delete[] biomecache;
  68 }
  69
  70
  71
  72 // just a PoC, obviously needs optimization later on (precalculate this)
  73 void BiomeManager::calcBiomes(s16 sx, s16 sy, float *heat_map,
  74         float *humidity_map, s16 *height_map, u8 *biomeid_map)
  75 {
  76         int i = 0;
  77         for (int y = 0; y != sy; y++) {
  78                 for (int x = 0; x != sx; x++, i++) {
  79                         float heat     = (heat_map[i] + 1) * 50;
  80                         float humidity = (humidity_map[i] + 1) * 50;
  81                         biomeid_map[i] = getBiome(heat, humidity, height_map[i])->id;
  82                 }
  83         }
  84 }
  85
  86
  87 Biome *BiomeManager::getBiome(float heat, float humidity, s16 y)
  88 {
  89         Biome *b, *biome_closest = NULL;
  90         float dist_min = FLT_MAX;
  91
  92         for (size_t i = 1; i < m_elements.size(); i++) {
  93                 b = (Biome *)m_elements[i];
  94                 if (!b || y > b->height_max || y < b->height_min)
  95                         continue;
  96
  97                 float d_heat     = heat     - b->heat_point;
  98                 float d_humidity = humidity - b->humidity_point;
  99                 float dist = (d_heat * d_heat) +
 100                                          (d_humidity * d_humidity);
 101                 if (dist < dist_min) {
 102                         dist_min = dist;
 103                         biome_closest = b;
 104                 }
 105         }
 106
 107         return biome_closest ? biome_closest : (Biome *)m_elements[0];
 108 }
 109
 110 void BiomeManager::clear()
 111 {
 112         for (size_t i = 1; i < m_elements.size(); i++) {
 113                 Biome *b = (Biome *)m_elements[i];
 114                 if (!b)
 115                         continue;
 116
 117                 m_resolver->cancelNode(&b->c_top);
 118                 m_resolver->cancelNode(&b->c_filler);
 119                 m_resolver->cancelNode(&b->c_stone);
 120                 m_resolver->cancelNode(&b->c_water);
 121                 m_resolver->cancelNode(&b->c_dust);
 122                 m_resolver->cancelNode(&b->c_dust_water);
 123         }
 124         m_elements.resize(1);
 125 }
 126