Turtle Track API

local old={}
turtle.x=0
turtle.y=0
turtle.z=0
turtle.facing="north"

if turtle.onEachMove==nil then
    local function onEachMove()
        return true
    end
    turtle.onEachMove=onEachMove
end

local function directionToNumber(direction)
    if direction == "north" then
        return 0
    elseif direction == "east" then
        return 1
    elseif direction == "south" then
        return 2
    elseif direction == "west" then
        return 3
    end
end

local function turnTo(direction)
    if ( directionToNumber(turtle.facing ) - 1) % 4 == directionToNumber(direction) then
        while turtle.facing ~= direction do
            turtle.turnLeft()
        end
    else
        while turtle.facing ~= direction do
            turtle.turnRight()
        end
    end
    return true
end
turtle.turnTo = turnTo

local function goto(x,y,z)
    local success = true
    local oldDirection = turtle.facing

    while turtle.z < z do --go z+
        success = success and turtle.up()
        if not success then return false end
    end
    while turtle.z > z do --go z-
        success = success and turtle.down()
        if not success then return false end
    end

    if turtle.x < x then --go x+
        turtle.turnTo("north")
        while turtle.x < x do
            success = success and turtle.forward()
            if not success then return false end
        end
    end
    if turtle.x > x then --go x-
        turtle.turnTo("north")
        while turtle.x > x do
            success = success and turtle.back()
            if not success then return false end
        end
    end

    if turtle.y < y then --go y+
        turtle.turnTo("east")
        while turtle.y < y do
            success = success and turtle.forward()
            if not success then return false end
        end
    end
    if turtle.y > y then --go y-
        turtle.turnTo("east")
        while turtle.y > y do
            success = success and turtle.back()
            if not success then return false end
        end
    end

    turtle.turnTo(oldDirection)
    return success
end
turtle.goto = goto

old.turtleUp=turtle.up
local function up()
    if old.turtleUp() then
        turtle.z = turtle.z+1
        turtle.onEachMove()
        return true
    else
        return false
    end
end
turtle.up=up

old.turtleDown=turtle.down
local function down()
    if old.turtleDown() then
        turtle.z=turtle.z-1
        turtle.onEachMove()
        return true
    else
        return false
    end
end
turtle.down=down

old.turtleForward=turtle.forward
local function forward()
    if old.turtleForward() then
        if turtle.facing == "north" then
            turtle.x=turtle.x+1
        elseif turtle.facing == "south" then
            turtle.x=turtle.x-1
        elseif turtle.facing == "east" then
            turtle.y=turtle.y+1
        elseif turtle.facing == "west" then
            turtle.y=turtle.y-1
        end
        turtle.onEachMove()
        return true
    else
        return false
    end
end
turtle.forward = forward

old.turtleBack=turtle.back
local function back()
    if old.turtleBack() then
        if turtle.facing == "north" then
            turtle.x=turtle.x-1
        elseif turtle.facing == "south" then
            turtle.x=turtle.x+1
        elseif turtle.facing == "east" then
            turtle.y=turtle.y-1
        elseif turtle.facing == "west" then
            turtle.y=turtle.y+1
        end
        turtle.onEachMove()
        return true
    else
        return false
    end
end
turtle.back = back

old.turtleTurnLeft=turtle.turnLeft
local function turnLeft()
    if old.turtleTurnLeft() then
        if turtle.facing == "north" then
            turtle.facing = "west"
        elseif turtle.facing == "west" then
            turtle.facing = "south"
        elseif turtle.facing == "south" then
            turtle.facing = "east"
        elseif turtle.facing == "east" then
            turtle.facing = "north"
        end
        turtle.onEachMove()
        return true
    else
        return false
    end
end
turtle.turnLeft = turnLeft

old.turtleTurnRight=turtle.turnRight
local function turnRight()
    if old.turtleTurnRight() then
        if turtle.facing == "north" then
            turtle.facing = "east"
        elseif turtle.facing == "east" then
            turtle.facing = "south"
        elseif turtle.facing == "south" then
            turtle.facing = "west"
        elseif turtle.facing == "west" then
            turtle.facing = "north"
        end
        turtle.onEachMove()
        return true
    else
        return false
    end
end
turtle.turnRight = turnRight