View difference between Paste ID: KsGsS49v and zvUaiBzY

 local ruin_deg = 10
 local light_chance = 100 --The greater the number, less is the chance.
 
 function generate_hallway_segment(pos, size, height, base_material, direction)
 	--pos - postion
 	--direction - north/south or east/west (2, 1)
 	local x,y,z = pos.x,pos.y,pos.z
 	local manip = minetest.get_voxel_manip()
 	local pos1 = {x = x + size/2, y = y + height, z = z + size/2}
 	local pos2 = {x = x - size/2, y = y, z = z - size/2}
 	local e1, e2 = manip:read_from_map(pos1, pos2)
 	local area = VoxelArea:new{MinEdge=e1, MaxEdge=e2}
 	local data = manip:get_data()
 
 	-- A block made out of the material --
 
 	for posX = pos2.x, pos1.x do
 		for posY = pos2.y, pos1.y do
 			for posZ = pos2.z, pos1.z do
 				data[area:index(posX, posY, posZ)] = base_material
 			end
 		end
 	end
 	-- Filled directionally with air --
 	if direction == 1 then
 		for internalX = pos2.x - 1, pos1.x + 1 do
 			for internalY = pos2.y + 1, pos1.y - 1 do
 				for internalZ = pos2.z + 1, pos1.z - 1 do
 					light = math.random(light_chance)
 					-- And Lights --
 					if light == 25 then
 						data[area:index(internalX, internalY, internalZ)] = c_light
 					else
 						data[area:index(internalX, internalY, internalZ)] = c_air
 					end
 				end
 			end
 		end
 	elseif direction == 2 then
 		for internalX = pos2.x + 1, pos1.x - 1 do
 			for internalY = pos2.y + 1, pos1.y - 1 do
 				for internalZ = pos2.z - 1, pos1.z + 1 do
 					light = math.random(50)
 					if light == 25 then
 						data[area:index(internalX, internalY, internalZ)] = c_light
 					else
 						data[area:index(internalX, internalY, internalZ)] = c_air
 					end
 				end
 			end
 		end
 	end