spawn_fast_walk.lua

local spawn_pos = minetest.string_to_pos(minetest.settings:get("static_spawnpoint") or "(0, 0, 0)")
local range = 150

local player_map = {} -- playername => boolean

minetest.register_on_leaveplayer(function(player)
	player_map[player:get_player_name()] = nil
end)

local timer = 0
minetest.register_globalstep(function(dtime)
	timer = timer + dtime
	if timer < 1 then
		return
	end

	timer = 0

	for _, player in ipairs(minetest.get_connected_players()) do
		local playername = player:get_player_name()
		local ppos = player:get_pos()

		local is_in_center = vector.distance(spawn_pos, ppos) < range

		if is_in_center and not player_map[playername] then
			-- moved to spawn
			player_monoids.speed:add_change(player, 2, "spawn_fast")
			player_map[playername] = true
		elseif not is_in_center and player_map[playername] then
			-- moved out of spawn
			player_monoids.speed:del_change(player, "spawn_fast")
			player_map[playername] = nil
		end
	end


end)