core.register_decoration({
  deco_type = "simple",
  sidelen = 16,
  fill_ratio = 0.0003,
  place_on = { "group:ground" },
  decoration = PyuTest.spawning_lootboxes
})

PyuTest.register_structure("igloo", "Igloo", {
  place_on = { "pyutest_blocks:snow_block" },
  fill_ratio = 0.00004,
  biomes = { "FrozenPlains" },
  rotation = "random",
  flags = "place_center_x, place_center_z",
  place_offset_y = 1
})

PyuTest.register_structure("desert_well", "DesertWell", {
  place_on = { "pyutest_blocks:sand_block" },
  fill_ratio = 0.00006,
  biomes = { "Desert" },
  rotation = "random"
})

PyuTest.register_structure("ice_spike", "IceSpike", {
  fill_ratio = 0.0008,
  place_on = {
    "pyutest_blocks:ice_block",
  },
  biomes = {
    "IceSpikes",
  },
})

PyuTest.register_structure("ocean_ruins", "OceanRuins", {
  fill_ratio = 0.0002,
  place_on = { "pyutest_blocks:gravel_block" },
  biomes = PyuTest.get_biomes_from_type(PyuTest.BIOME_TYPES.OCEAN),
  y_max = PyuTest.OVERWORLD_DEEP_OCEAN_MAX + 4,
  y_min = PyuTest.OVERWORLD_DEEP_OCEAN_MIN,
  spawn_by = { "pyutest_blocks:water_source" },
  num_spawn_by = 2
})

PyuTest.register_structure("fossil", "Fossil", {
  fill_ratio = 9 / 10000, -- 9 out of every 10000 blocks should spawn fossils
  place_on = {
    "pyutest_blocks:molten_rock_block",
    "pyutest_blocks:magma"
  },
  biomes = PyuTest.LavaWorld.biome_names
})