minetest_game/mods/spawn/init.lua
2024-09-08 22:07:20 +02:00

136 lines
2.9 KiB
Lua

-- Always load the API
----------------------
dofile(minetest.get_modpath(minetest.get_current_modname()) .. "/api.lua")
-- Disable biome-search implementation on unsuitable mapgens
------------------------------------------------------------
local mg_name = minetest.get_mapgen_setting("mg_name")
if mg_name == "v6" or mg_name == "singlenode" then
return
end
-- Parameters
-------------
-- Resolution of search grid in nodes.
local res = 64
-- Number of points checked in the square search grid (edge * edge).
local checks = 128 * 128
-- Starting point for biome checks. This also sets the y co-ordinate for all
-- points checked, so the suitable biomes must be active at this y.
local pos = {x = 0, y = 8, z = 0}
-- Table of suitable biomes and matching API function
local biome_ids = {}
function spawn.add_suitable_biome(biome)
local id = minetest.get_biome_id(biome)
assert(id ~= nil)
biome_ids[id] = true
end
for _, name in ipairs({
"taiga", "coniferous_forest", "deciduous_forest", "grassland", "savanna"
}) do
local id = minetest.get_biome_id(name)
if id then
biome_ids[id] = true
end
end
-- End of parameters
--------------------
-- Direction table
local dirs = {
vector.new(0, 0, 1),
vector.new(-1, 0, 0),
vector.new(0, 0, -1),
vector.new(1, 0, 0),
}
-- Initial variables
local edge_len = 1
local edge_dist = 0
local dir_step = 0
local dir_ind = 1
local searched = false
local success = false
local spawn_pos = {}
-- Get world 'mapgen_limit' and 'chunksize' to calculate 'spawn_limit'.
-- This accounts for how mapchunks are not generated if they or their shell exceed
-- 'mapgen_limit'.
local mapgen_limit = tonumber(minetest.get_mapgen_setting("mapgen_limit"))
local chunksize = tonumber(minetest.get_mapgen_setting("chunksize"))
local spawn_limit = math.max(mapgen_limit - (chunksize + 1) * 16, 0)
-- Functions
------------
-- Get next position on square search spiral
local function next_pos()
if edge_dist == edge_len then
edge_dist = 0
dir_ind = dir_ind + 1
if dir_ind == 5 then
dir_ind = 1
end
dir_step = dir_step + 1
edge_len = math.floor(dir_step / 2) + 1
end
local dir = dirs[dir_ind]
local move = vector.multiply(dir, res)
edge_dist = edge_dist + 1
return vector.add(pos, move)
end
-- Spawn position search
local function search()
for iter = 1, checks do
local biome_data = minetest.get_biome_data(pos)
-- Sometimes biome_data is nil
if biome_data and biome_ids[biome_data.biome] then
local spawn_y = minetest.get_spawn_level(pos.x, pos.z)
if spawn_y then
spawn_pos = vector.new(pos.x, spawn_y, pos.z)
return true
end
end
pos = next_pos()
-- Check for position being outside world edge
if math.abs(pos.x) > spawn_limit or math.abs(pos.z) > spawn_limit then
return false
end
end
return false
end
function spawn.get_default_pos()
-- Search for spawn position once per server session
if not searched then
success = search()
searched = true
end
return success and spawn_pos
end