Track coordinates using normal turtle move functions

After executing this code, until reboot all calls to turtle.up(), turtle.down(), ect will track the position of your turtle. All you have to do is call init() first, with the starting coordinates

This is especially useful when using the shell command "go" to move your turtle around, as changes to the coordinates will still be tracked!

It does this using the do…end command to create a local scope. It then stores a local reference to the old turtle.forward(), and binds turtle.forward() to a new closure that references the old turtle.forward() as an upvalue. (a process sometimes referred to as sandboxing) Future calls to turtle.forward() will call my function, which will in turn call the old turtle.forward() and then increment X or Z based on the value of FACE if it succeeded.

SOUTH = 0
WEST = 1
NORTH = 2
EAST = 3
function init(x, y, z, face)
  X = x
  Y = y
  Z = z
  FACE = face
end

do
  local function track_up()
	Y = Y + 1
  end
  local function track_down()
	Y = Y - 1
  end

  local function track_forward()
	if FACE == SOUTH then
	  Z = Z + 1
	elseif FACE == WEST then
	  X = X - 1
	elseif FACE == NORTH then
	  Z = Z - 1
	elseif FACE == EAST then
	  X = X + 1
	end
  end
  local function track_back()
	if FACE == SOUTH then
	  Z = Z - 1
	elseif FACE == WEST then
	  X = X + 1
	elseif FACE == NORTH then
	  Z = Z + 1
	elseif FACE == EAST then
	  X = X - 1
	end
  end
  local function track_left()
	FACE = (FACE - 1) % 4
  end
  local function track_right()
	FACE = (FACE + 1) % 4
  end
  local raw_up = turtle.up
  local raw_down = turtle.down
  local raw_forward = turtle.forward
  local raw_back = turtle.back
  local raw_left = turtle.turnLeft
  local raw_right = turtle.turnRight
  turtle.up = function()
	if raw_up() then
	  track_up()
	  return true
	else
	  return false
	end
  end
  turtle.down = function()
	if raw_down() then
	  track_down()
	  return true
	else
	  return false
	end
  end
  turtle.forward = function()
	  if raw_forward() then
	  track_forward()
	  return true
	else
	  return false
	end
  end
  turtle.back = function()
	if raw_back() then
	  track_back()
	  return true
	else
	  return false
	end
  end
  turtle.left = function()
	raw_left()
	track_left()
  end
  turtle.right = function()
	raw_right()
	track_right()
  end
end

hey this is a little bit of my idea(see turtle controller) but my api rerotates the turtle if he will be forward but its facing left :-)

Yeah, I saw that post and I wanted to add to it the idea of actually changing the turtle.up() functions instead of making my own. This isn't an attempt to create a finished product, just an example of how to overwrite the turtle api.

The point of this "api" is to provide passive tracking of ALL movement, no mater how it is done, because it listens to EVERY call. ANY program that moves the turtle will update X Y Z and FACE. Even pre-loaded ones that come from computercraft. There is no way to go around the coordinate tracking in this api, that is why it is so powerful.

Also, I intentionally didn't include any functions for actually using the coordinates, that i leave up to you :)/>