05_navigation.lua

local component = require("component")

local original_invoke=component.invoke
component.invoke=function(address, method, ...)
    if component.type(address)=="navigation" and method=="getPosition" then
        local x,y,z=original_invoke(address, method, ...)
        if not x then
            local wp = original_invoke(address,"findWaypoints",... or 400)[1]
            if wp then
                local nums=wp.label:gmatch("%-?%d+")
                x=nums()
                y=nums()
                z=nums()
                return x+wp.position[1]+0.5,y+wp.position[2]+0.5,z+wp.position[3]+0.5
            else
                return nil,"out of range","waypoints not found"
            end
        else
            return x,y,z
        end
    else
        return original_invoke(address, method, ...)
    end
end