Turtle Adventurer V2

-- Turtle Adventurer V2
-- By CaptainSpaceCat
-- This program will send a turtle off into the wilderness to travel in a straight line as far as possible
-- You must equip the turtle with 3 chunk loaders so that it can load the chunk it's in and the next one
-- You should also give it an rftools Matter Receiver so that you can teleport to it once it gets thousands of blocks away!
-- NOTE: you MUST start the turtle ONE BLOCK AWAY from the edge of a chunk, facing INTO the chunk
-- otherwise the chunk loaders won't work properly

-- CHANGES
-- Turtle will now log all landmasses it travels over
-- it does this by keeping track of its coordinates and logging chunks where it has to break terrain at least once
-- you should place it one block above sea level for this to work as well as possible
-- you MUST enter its initial coordinates and rotation accurately for this to be useful

shell.run("delete travel_log")

local anchorSlot = 1
local receiverSlot = 2
local tArgs = {...}
local terrainFlag = false

local coords = {}
local chunks = turtle.getFuelLevel() / 48
local function getCoords()
    print("Turtle's X coordinate: ")
    coords.x = tonumber(read())
    print("Turtle's Y coordinate: ")
    coords.y = tonumber(read())
    print("Turtle's Z coordinate: ")
    coords.z = tonumber(read())
    print("Turtle's direction: ")
    print("1 - north")
    print("2 - east")
    print("3 - west")
    print("4 - south")
    coords.f = tonumber(read())
    print("Desired number of chunks to travel:")
    print("(Leave empty to go as far as fuel allows)")
    local c = tonumber(read())
    if not c == nil then
        chunks = c
    end
end

local function log(message)
    handle = fs.open("travel_log", "a")
    handle.writeLine(message)
    handle.close()
end

local dirTab = {
    {0, -1}, --north
    {1, 0}, --south
    {0, 1}, --east
    {-1, 0} --west
}

local function forward(num)
    num = num or 1
    for i = 1, num do
        if turtle.detect() then
            turtle.dig()
            terrianFlag = true
        end
        turtle.forward()
        coords.x = coords.x + dirTab[coords.f][1]
        coords.z = coords.z + dirTab[coords.f][2]
    end
end

local function up(num)
    num = num or 1
    for i = 1, num do
        if turtle.detectUp() then
            turtle.digUp()
        end
        turtle.up()
        coords.y = coords.y + 1
    end
end

local function down(num)
    num = num or 1
    for i = 1, num do
        if turtle.detectDown() then
            turtle.digDown()
        end
        turtle.down()
        coords.y = coords.y - 1
    end
end

local function left(num)
    num = num or 1
    for i = 1, num do
        turtle.turnLeft()
        coords.f = ((coords.f + 2) % 4) + 1
    end
end

local function right(num)
    num = num or 1
    for i = 1, num do
        turtle.turnRight()
        coords.f = (coords.f % 4) + 1
    end
end

local function placeAnchor()
    turtle.dig()
    turtle.select(anchorSlot)
    turtle.place()
end

local function placeAnchorUp()
    turtle.digUp()
    turtle.select(anchorSlot)
    turtle.placeUp()
end

local function pickupAnchor()
    turtle.select(anchorSlot)
    turtle.dig()
end

local function loop(chunks)
    for i = 1, chunks do
        terrainFlag = false
        forward(14)
        placeAnchor()
        placeAnchorUp()
        left(2)
        forward(14)
        pickupAnchor()
        left(2)
        forward(14)
        right()
        forward()
        left()
        forward()
        up()
        left()
        forward()
        left()
        pickupAnchor()
        left(2)
        forward()
        down()
        if terrainFlag then
            log(tostring(coords.x) .. "|" .. tostring(coords.z))
        end
    end
end

local function placeReceiver()
    turtle.select(receiverSlot)
    turtle.dig()
    turtle.place()
end

getCoords()
print("Adventuring approximately " .. tostring(chunks) .. " chunks!")
loop(chunks)
placeReceiver()