init.lua

   1 biomeinfo = {}
   2
   3 -- Copied from mapgen_v6.h
   4 local MGV6_FREQ_HOT = 0.4
   5 local MGV6_FREQ_SNOW = -0.4
   6 local MGV6_FREQ_TAIGA = 0.5
   7 local MGV6_FREQ_JUNGLE = 0.5
   8
   9 -- Biome types
  10 local BT_NORMAL = "Normal"
  11 local BT_TUNDRA = "Tundra"
  12 local BT_TAIGA = "Taiga"
  13 local BT_DESERT = "Desert"
  14 local BT_JUNGLE = "Jungle"
  15
  16 -- Get mapgen settings
  17
  18 local seed = tonumber(minetest.get_mapgen_setting("seed")) or 0
  19
  20 local mgv6_perlin_biome, mgv6_perlin_humidity, mgv6_np_biome
  21
  22 -- v6 default noiseparams are hardcoded here because Minetest doesn't give us those
  23 local mgv6_np_biome_default = {
  24         offset = 0,
  25         scale = 1,
  26         spread = { x = 500, y = 500, z = 500},
  27         seed = 9130,
  28         octaves = 3,
  29         persistence = 0.50,
  30         lacunarity = 2.0,
  31         flags = "eased",
  32 }
  33 local mgv6_np_humidity_default = {
  34         offset = 0.5,
  35         scale = 0.5,
  36         spread = { x = 500, y = 500, z = 500},
  37         seed = 72384,
  38         octaves = 3,
  39         persistence = 0.50,
  40         lacunarity = 2.0,
  41         flags = "eased",
  42 }
  43
  44 local v6_flags_str = minetest.get_mapgen_setting("mgv6_spflags")
  45 if v6_flags_str == nil then
  46         v6_flags_str = ""
  47 end
  48 local v6_flags = string.split(v6_flags_str)
  49 local v6_use_snow_biomes = true
  50 local v6_use_jungles = true
  51 -- TODO: Implement biome blend.
  52 -- Currently we pretend biome blend is disabled.
  53 -- This just makes the calculations inaccurate near biome boundaries,
  54 -- but should be fine otherwise.
  55 local v6_use_biome_blend = false
  56 for f=1, #v6_flags do
  57         local flag = v6_flags[f]:trim()
  58         if flag == "nosnowbiomes" then
  59                 v6_use_snow_biomes = false
  60         end
  61         if flag == "snowbiomes" then
  62                 v6_use_snow_biomes = true
  63         end
  64         if flag == "nojungles" then
  65                 v6_use_jungles = false
  66         end
  67         if flag == "jungles" then
  68                 v6_use_jungles = true
  69         end
  70         if flag == "nobiomeblend" then
  71                 v6_use_biome_blend = false
  72         end
  73 -- TODO
  74 --      if flag == "biomeblend" then
  75 --              v6_use_biome_blend = true
  76 --      end
  77 end
  78 -- Force-enable jungles when snowbiomes flag is set
  79 if v6_use_snow_biomes then
  80         v6_use_jungles = true
  81 end
  82 local v6_freq_desert = tonumber(minetest.get_mapgen_setting("mgv6_freq_desert") or 0.45)
  83
  84 local NOISE_MAGIC_X = 1619
  85 local NOISE_MAGIC_Y = 31337
  86 local NOISE_MAGIC_Z = 52591
  87 local NOISE_MAGIC_SEED = 1013
  88 local noise2d = function(x, y, seed)
  89         -- TODO: implement noise2d function for biome blend
  90         return 0
  91 --[[
  92         local n = (NOISE_MAGIC_X * x + NOISE_MAGIC_Y * y
  93         + NOISE_MAGIC_SEED * seed) & 0x7fffffff;
  94         n = (n >> 13) ^ n;
  95         n = (n * (n * n * 60493 + 19990303) + 1376312589) & 0x7fffffff;
  96         return 1.0 - n / 0x40000000;
  97 ]]
  98 end
  99
 100 biomeinfo.all_v6_biomes = {
 101         BT_NORMAL,
 102         BT_DESERT,
 103         BT_JUNGLE,
 104         BT_TUNDRA,
 105         BT_TAIGA
 106 }
 107
 108 local function init_perlins()
 109         if not mgv6_perlin_biome then
 110                 mgv6_np_biome = minetest.get_mapgen_setting_noiseparams("mgv6_np_biome")
 111                 if not mgv6_np_biome then
 112                         mgv6_np_biome = mgv6_np_biome_default
 113                         minetest.log("action", "[biomeinfo] Using hardcoded mgv6_np_biome default")
 114                 end
 115                 mgv6_perlin_biome = minetest.get_perlin(mgv6_np_biome)
 116         end
 117         if not mgv6_perlin_humidity then
 118                 local np_humidity = minetest.get_mapgen_setting_noiseparams("mgv6_np_humidity")
 119                 if not np_humidity then
 120                         np_humidity = mgv6_np_humidity_default
 121                         minetest.log("action", "[biomeinfo] Using hardcoded mgv6_np_humidity default")
 122                 end
 123                 mgv6_perlin_humidity = minetest.get_perlin(np_humidity)
 124         end
 125 end
 126
 127 function biomeinfo.get_active_v6_biomes()
 128         local biomes = { BT_NORMAL, BT_DESERT }
 129         if v6_use_jungles then
 130                 table.insert(biomes, BT_JUNGLE)
 131         end
 132         if v6_use_snow_biomes then
 133                 table.insert(biomes, BT_TUNDRA)
 134                 table.insert(biomes, BT_TAIGA)
 135         end
 136         return biomes
 137 end
 138
 139 function biomeinfo.get_v6_heat(pos)
 140         init_perlins()
 141         if not mgv6_perlin_biome then
 142                 return nil
 143         end
 144         local bpos = vector.floor(pos)
 145         -- The temperature noise needs a special offset (see calculateNoise in mapgen_v6.cpp)
 146         return mgv6_perlin_biome:get_2d({x=bpos.x + mgv6_np_biome.spread.x*0.6, y=bpos.z + mgv6_np_biome.spread.z*0.2})
 147 end
 148
 149 function biomeinfo.get_v6_humidity(pos)
 150         init_perlins()
 151         if not mgv6_perlin_humidity then
 152                 return nil
 153         end
 154         local bpos = vector.floor(pos)
 155         return mgv6_perlin_humidity:get_2d({x=bpos.x, y=bpos.z})
 156 end
 157
 158 -- Returns the v6 biome at pos.
 159 -- Returns a string representing the biome name.
 160 function biomeinfo.get_v6_biome(pos)
 161         init_perlins()
 162         local bpos = vector.floor(pos)
 163         -- Based on the algorithm MapgenV6::getBiome in mapgen_v6.cpp
 164
 165         local pos2d = {x=bpos.x, y=bpos.z}
 166         if not mgv6_perlin_biome or not mgv6_perlin_humidity then
 167                 return "???"
 168         end
 169         local d = biomeinfo.get_v6_heat(bpos)
 170         local h = biomeinfo.get_v6_humidity(bpos)
 171
 172         if (v6_use_snow_biomes) then
 173                 local blend
 174                 if v6_use_biome_blend then
 175                         blend = noise2d(pos2d.x, pos2d.y, seed) / 40
 176                 else
 177                         blend = 0
 178                 end
 179
 180                 if (d > MGV6_FREQ_HOT + blend) then
 181                         if (h > MGV6_FREQ_JUNGLE + blend) then
 182                                 return BT_JUNGLE
 183                         end
 184                         return BT_DESERT
 185                 end
 186                 if (d < MGV6_FREQ_SNOW + blend) then
 187                         if (h > MGV6_FREQ_TAIGA + blend) then
 188                                 return BT_TAIGA
 189                         end
 190                         return BT_TUNDRA
 191                 end
 192                 return BT_NORMAL
 193         end
 194
 195         if (d > v6_freq_desert) then
 196                 return BT_DESERT
 197         end
 198
 199         if ((v6_use_biome_blend) and (d > v6_freq_desert - 0.10) and
 200                         ((noise2d(pos2d.x, pos2d.y, seed) + 1.0) > (v6_freq_desert - d) * 20.0)) then
 201                 return BT_DESERT
 202         end
 203
 204         if ((v6_use_jungles) and (h > 0.75)) then
 205                 return BT_JUNGLE
 206         end
 207
 208         return BT_NORMAL
 209 end
 210
 211