A random mapgen for minetest

random_mapgen.lua

local count = 0
local c_air = minetest.get_content_id("air")

local function count_nodes()
	for i,_ in pairs(minetest.registered_nodes) do
		count = count+1
	end
end

minetest.register_on_generated(function(minp, maxp, seed)
	if count == 0 then
		count_nodes()
	end

	local pr = PseudoRandom(seed+68)

	local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
	local data = vm:get_data()
	local area = VoxelArea:new{MinEdge=emin, MaxEdge=emax}

	for i in area:iterp(minp, maxp) do
		if data[i] ~= c_air then
			data[i] = pr:next(1, count)
		end
	end

	vm:set_data(data)
	vm:write_to_map()
end)