mapgen_rivers/load.lua

local worldpath = minetest.get_worldpath() .. "/river_data/"

local function load_map(filename, bytes, signed, size)
	local file = io.open(worldpath .. filename, 'r')
	local data = file:read('*all')
	if #data < bytes*size then
		data = minetest.decompress(data)
	end

	local map = {}

	for i=1, size do
		local i0, i1 = (i-1)*bytes+1, i*bytes
		local elements = {data:byte(i0, i1)}
		local n = elements[1]
		if signed and n >= 128 then
			n = n - 256
		end

		for j=2, bytes do
			n = n*256 + elements[j]
		end

		map[i] = n
	end
	file:close()

	return map
end

return load_map