local math, vector, minetest, mcl_mobs = math, vector, minetest, mcl_mobs
local mob_class = mcl_mobs.mob_class

-- check line of sight (BrunoMine)
function mob_class:line_of_sight(pos1, pos2, stepsize)

	stepsize = stepsize or 1

	local s, pos = minetest.line_of_sight(pos1, pos2, stepsize)

	-- normal walking and flying mobs can see you through air
	if s == true then
		return true
	end

	-- New pos1 to be analyzed
	local npos1 = {x = pos1.x, y = pos1.y, z = pos1.z}

	local r, pos = minetest.line_of_sight(npos1, pos2, stepsize)

	-- Checks the return
	if r == true then return true end

	-- Nodename found
	local nn = minetest.get_node(pos).name

	-- Target Distance (td) to travel
	local td = vector.distance(pos1, pos2)

	-- Actual Distance (ad) traveled
	local ad = 0

	-- It continues to advance in the line of sight in search of a real
	-- obstruction which counts as 'normal' nodebox.
	while minetest.registered_nodes[nn]
	and minetest.registered_nodes[nn].walkable == false do

		-- Check if you can still move forward
		if td < ad + stepsize then
			return true -- Reached the target
		end

		-- Moves the analyzed pos
		local d = vector.distance(pos1, pos2)

		npos1.x = ((pos2.x - pos1.x) / d * stepsize) + pos1.x
		npos1.y = ((pos2.y - pos1.y) / d * stepsize) + pos1.y
		npos1.z = ((pos2.z - pos1.z) / d * stepsize) + pos1.z

		-- NaN checks
		if d == 0
		or npos1.x ~= npos1.x
		or npos1.y ~= npos1.y
		or npos1.z ~= npos1.z then
			return false
		end

		ad = ad + stepsize

		-- scan again
		r, pos = minetest.line_of_sight(npos1, pos2, stepsize)

		if r == true then return true end

		-- New Nodename found
		nn = minetest.get_node(pos).name

	end

	return false
end