bfm: ComputerCraft turtle program to build a floor over open spaces

buildFloorMatrix.lua

-- buildFloorMatrix build a floor over open spaces
-- by Alexander "SquidLord" Williams (Saladin Vrai)

-- "buildFloorMatrix [r|r]"
--    Place drone over near edge of opening. [R|L] defines which way 
--      the drone shouldturn at the end of the opening.

-- Gist: https://gist.github.com/SquidLord/4748385

-- The MIT License (MIT)

-- Copyright (c) 2012 Alexander Williams

-- Permission is hereby granted, free of charge, to any person obtaining a copy
-- of this software and associated documentation files (the "Software"), to deal
-- in the Software without restriction, including without limitation the rights
-- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-- copies of the Software, and to permit persons to whom the Software is
-- furnished to do so, subject to the following conditions:

-- The above copyright notice and this permission notice shall be included in all
-- copies or substantial portions of the Software.

-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-- SOFTWARE.

-- Requires squidlib (https://gist.github.com/SquidLord/4746742)
os.loadAPI("squid/squidlib")

-- Requires EGPS (A* pathfinding): https://gist.github.com/SquidLord/4741746
os.loadAPI("squid/egps")

-- usage()
--    Print usage text
function usage()
  print("buildFloorMatrix [r|l]")
  print("  r|l says which way to turn at the end of the first row.")
end

-- process Step(Turn, JustTurned)
--    Do for every block passed over; Turn is the direction to turn on
--      not finding a hole; JustTurned is whether you've just not found a block
--    Not finding a block twice is the trigger to return to start
function step(Turn, JustTurned, Slt)
  if turtle.getFuelLevel() < 300 then  -- Are we out of fuel?
    print("  Insufficient fuel; RTB; please fuel")
    return false
  end
  if turtle.detectDown() then -- Is there a block below?
    if JustTurned then -- Have we just turned at the end of row?
      print("  End of area; RTB")
      squidlib.redCast("Completed flooring area.")
      return true
    else
      print("  End of row; turning "..Turn)
      if Turn == "r" then
        egps.back()
        egps.turnRight()
        egps.forward()
        return step("r", true, Slt)
      else
        egps.back()
        egps.turnLeft()
        egps.forward()
        return step("l", true, Slt)
      end -- Turn check
    end -- JustTurned
  else -- There is not a block below
    if (turtle.getItemCount(Slt) == 0) then -- Are we out of flooring in the current inv slot?
      print("  Out of flooring in slot "..Slt)
      if (Slt == 16) then -- Is this the last slot?
        print("  Empty of flooring; RTB")
        return false
      else
        turtle.select(Slt+1)
        return step(Turn, false, Slt+1) -- Re-enter with new slot
      end
    else
      turtle.placeDown()
      egps.forward()
      return step(Turn, false, Slt) -- Continue ahead with the same Turn
    end
  end
end

-- Load vars/args
local ARGS = {...}

-- Identify
term.clear()
print("SquidOS buildFloorMatrix Startup ...")
print("  Node:"..squidlib.labelString())

-- If no arguments, print usage and fail out
if (#ARGS == 0) then
  usage()
  return false
end

-- Find out the start position
STARTPOSX, STARTPOSY, STARTPOSZ, STARTPOSFACE = egps.setLocationFromGPS()

if not ((ARGS[1] == "r") or (ARGS[1] == "l")) then
  usage()
  return false
end

turtle.select(1)
egps.forward()
local RETVAL = step(ARGS[1], false, 1)
egps.moveTo(STARTPOSX, STARTPOSY, STARTPOSZ, STARTPOSFACE)
print("  Done")
squidlib.redCast("Done with floor laying")
return RETVAL