blockgame/mods/bg_tree/api.lua

local modname = minetest.get_current_modname()

blockgame.tree = blockgame.tree or {}
local api = blockgame.tree

function api.find_bottom_log (pos, max_height)
	local pos = vector.copy(pos)
	local step = 0
	while step < max_height do
		local new_pos = blockgame.vector.get_below(pos)
		if minetest.get_node(new_pos).name ~= modname .. ":log" then
			return pos
		end
		pos = new_pos

		step = step + 1
	end
	return nil
end