Minetest get light from VoxelManip data

gistfile1.lua

local light_lookup = {
		{4250+125, 150},
		{4500+125, 150},
		{4750+125, 250},
		{5000+125, 350},
		{5250+125, 500},
		{5500+125, 675},
		{5750+125, 875},
		{6000+125, 1000},
		{6250+125, 1000}
	}

function get_day_night_ratio(time)

	--make sure time is between 0 and 240000
	if time < 0 then
		time = time - (((time*-1)/24000)*24000)
	end
	if time > 24000 then
		time = time + ((time/24000)*24000)
	end

	--invert time for sunset
	if time > 12000 then
		time = 24000 - time
	end

	local dnr = 1000

	for i=1,#light_lookup,1 do
		if time < light_lookup[i][1] then
			dnr = light_lookup[i][2]
			break
		end
	end

	return dnr
end

function get_light_from_voxelmanip(node_data,light_data,area,pos,time)

	if not area:containsp(pos) then
		return minetest.get_node_light(pos, time)
	end

	pos = vector.round(pos)
	local index = area:indexp(pos)

	local raw_light_value = light_data[index]

	if raw_light_value == nil then
		return nil
	end

	local light_day   = nil
	local light_night = nil

	--read node information
	local content_id = node_data[index]
	local nodename = minetest.get_name_from_content_id(content_id)
	local nodedef = minetest.registered_nodes[nodename]

	-- check for solid node
	if nodedef.paramtype ~= "light" then
		light_day = 0
		light_night = 0
	else
		light_day   = raw_light_value % 16
		light_night = (raw_light_value - light_day)/16
	end

	--check lightsource
	if nodedef.light_source ~= nil then
		if nodedef.light_source > light_day then
			light_day = nodedef.light_source
		end
		if nodedef.light_source > light_night then
			light_night = nodedef.light_source
		end
	end

	time = time *24000
	time = time %24000

	local dnr = get_day_night_ratio(time)

	local c = 1000
	local current_light = ((dnr * light_day + (c-dnr) * light_night))/c
	if(current_light > LIGHT_MAX+1) then
		current_light = LIGHT_MAX+1
	end

	return math.floor(current_light)
end