-- "Record" the chunks being generated by the core mapgen

minetest.register_on_generated(function(minp, maxp, blockseed)
        biome_lib.blocklist_aircheck[#biome_lib.blocklist_aircheck + 1] = { minp, maxp }
end)

minetest.register_on_generated(function(minp, maxp, blockseed)
        biome_lib.blocklist_no_aircheck[#biome_lib.blocklist_no_aircheck + 1] = { minp, maxp }
end)

-- "Play" them back, populating them with new stuff in the process

minetest.register_globalstep(function(dtime)
        if dtime < 0.2 and    -- don't attempt to populate if lag is already too high
          (#biome_lib.blocklist_aircheck > 0 or #biome_lib.blocklist_no_aircheck > 0) then
                biome_lib.globalstep_start_time = minetest.get_us_time()
                biome_lib.globalstep_runtime = 0
                while (#biome_lib.blocklist_aircheck > 0 or #biome_lib.blocklist_no_aircheck > 0)
                  and biome_lib.globalstep_runtime < 200000 do  -- 0.2 seconds, in uS.
                        if #biome_lib.blocklist_aircheck > 0 then
                                biome_lib:generate_block_with_air_checking()
                        end
                        if #biome_lib.blocklist_no_aircheck > 0 then
                                biome_lib:generate_block_no_aircheck()
                        end
                        biome_lib.globalstep_runtime = minetest.get_us_time() - biome_lib.globalstep_start_time
                end
        end
end)