position2

-- should be the same as as position
-- but uses a table with positions
-- so that several positions can be used

x="x" -- forward, back
y="y" -- up, down
z="z" -- right, left (not turn)
rot="rot" -- direction/rotation the turtle is facing

-- this can be used to make sure
-- the turtle isn't outside a
-- cube of a certain size
function getLargest(posT)
  -- make local copies of the coordinates
  -- but use the absolute value
  local x=math.abs(posT[x])
  local y=math.abs(posT[y])
  local z=math.abs(posT[z])
  if x>y then
    if x>z then
      return x
    else
      return z
    end
  else
    if y>z then
      return y
    else
      return z
    end
  end
end

function printit(posT)
  print("before: "..posT[x].." "..posT[y].." "..posT[z].." "..rot)
end

function reset(posT)
  posT[x]=0
  posT[y]=0
  posT[z]=0
  posT[rot]=0
end

function getAPosT(x,y,z,rot)
  if x==nil then x=0 end
  if y==nil then y=0 end
  if z==nil then z=0 end
  if rot==nil then rot=0 end
  local posT={
    x=x,
    y=y,
    z=z,
    rot=rot,
  }
  return posT
end

-- put function in the table
horzT={
  [0]=function(posT,length)
    posT[x]=posT[x]+length
  end,
  [1]=function(posT,length)
    posT[z]=posT[z]+length
  end,
  [2]=function(posT,length)
    posT[x]=posT[x]-length
  end,
  [3]=function(posT,length)
    posT[z]=posT[z]-length
  end,
}

-- table that can update the coordinates
-- if you go a given length in the
-- in a direction
updateT={
  f=function(posT,length)
    horzT[rot](posT,length)
  end,
  b=function(posT,length)
    horzT[rot](posT,length)
  end,
  u=function(posT,length)
    y=y+length
  end,
  d=function(posT,length)
    y=y-length
  end,
  r=function(posT,length)
   posT[rot]=(posT[rot]+length)%4
  end,
  l=function(posT,length)
    posT[rot]=(posT[rot]-length)%4
  end,
}

-- updates the position values
-- given the input values
-- returns nil
function update(posT, dir, length)
  --print("before: "..x.." "..y.." "..z.." "..rot)
  --print(dir.." "..length)
  updateT[dir](posT, length)
  --print("after: "..x.." "..y.." "..z.." "..rot)
end

function whatIf(posT, dir, length)
  update(posT, dir,length)
  local a, b, c, d=get(posT)
  update(posT, dir,-length)
  return a,b,c,d
end

function whatIfLargest(posT, dir, length)
  update(posT, dir,length)
  local res=getLargest()
  --print(x.." "..y.." "..z" "..rot)
  update(posT, dir,-length)
  return res
end

-- returns the position values
-- x,y,z,rot
function get(posT)
  return posT[x], posT[y],posT[z], posT[rot]
end