GauMaze v1.5

-- Maze building script for MC computercraft turtles
-- Turtle requires the proper amount of fuel to build before it will start, does not attempt to refuel,
--   this must be done manually
-- Builds the maze to the front and left of the turtle.
-- Can specify size with command line arguments. Example ( to make a 21x9 maze) : Maze 21 9

local maze = {}
local args = { ... }
local xMax = tonumber(args[1])
local yMax = tonumber(args[2])

local selection = 1
turtle.select(1)

if #args < 2 then
  xMax = 7
  yMax = 7
end

if ( xMax < 7 ) then xMax = 7 end
if ( yMax < 7 ) then yMax = 7 end
if ( xMax % 2 == 0 ) then xMax = xMax + 1 end
if ( yMax % 2 == 0 ) then yMax = yMax + 1 end

local fuelNeeded = yMax * xMax * 3 + yMax * 2 + xMax * 2
if ( turtle.getFuelLevel() < fuelNeeded ) then
  print("Not enough fuel, need at least " .. fuelNeeded .. " to make a maze of that size")
  return
end

function tryForward()
  turtle.dig()
  if ( turtle.forward() == false ) then
    print("Get out of my way!!")
    while ( turtle.forward() == false ) do
      os.sleep(2)
    end
  end
end


function initilize(x, y)
  local i = 1
  while i <= x do
    maze[i] = {}
    local j = 1
    while j <= y do
      if ( i % 2 == 0 ) and ( j % 2 == 0 ) then
        maze[i][j] = 2
      else
        maze[i][j] = 1
      end
      j = j + 1
    end
    i = i + 1
  end
end

function arrayToCell(A)
  return ( A - 1 ) / 2
end

function cellToArray(C)
  return C * 2
end

function isOpenCell( cell )
  local x = cell[1]
  local y = cell[2]

  if ( x < 1 or y < 1 ) then return false end

  local cellXMax = arrayToCell( xMax )
  local cellYMax = arrayToCell( yMax )

  if ( x > cellXMax or y > cellYMax ) then return false end

  local arrayX = cellToArray(x)
  local arrayY = cellToArray(y)

  if ( maze[arrayX][arrayY] == 2 ) then
     return true
  else
     return false
  end

end

function getNeighbors ( cell )
  local x = cell[1]
  local y = cell[2]

  local neighbors = {}
  local testCell

  testCell = { x , y + 1 }
  if ( isOpenCell(testCell) ) then table.insert(neighbors,testCell) end

  testCell = { x , y - 1 }
  if ( isOpenCell(testCell) ) then table.insert(neighbors,testCell) end

  testCell = { x + 1 , y }
  if ( isOpenCell(testCell) ) then table.insert(neighbors,testCell) end

  testCell = { x - 1, y }
  if ( isOpenCell(testCell) ) then table.insert(neighbors,testCell) end

  return neighbors
end

function addToMaze( cell )
  local x = cellToArray( cell[1] )
  local y = cellToArray( cell[2] )
  maze[x][y] = 0
end

function addToOpenCells( cell, openCells )
  local newCell = { cell[1] , cell[2] }


  openCells = table.insert(openCells,newCell)

end

function openWall( cell, cell2 )
  local x1 = cellToArray( cell[1] )
  local x2 = cellToArray( cell2[1] )
  local y1 = cellToArray( cell[2] )
  local y2 = cellToArray( cell2[2] )
  local midX = ( x1 + x2 ) / 2
  local midY = ( y1 + y2 ) / 2
  maze[midX][midY] = 0

end

function makeMaze()


  local openCells = { {math.random(arrayToCell(xMax)),math.random(arrayToCell(yMax))} }

  while #openCells >= 1 do
    local pickedCellNumber = math.random(#openCells)
    local currentCell = openCells[pickedCellNumber]
    addToMaze( currentCell )

    local neighborCells = getNeighbors( currentCell )

    if ( #neighborCells >= 1 ) then
        local neighbor = 1
        --while neighbor <= #neighborCells do
        --   addToOpenCells( neighborCells[neighbor], openCells )
        --   neighbor = neighbor + 1
        --end

        neighbor = math.random(#neighborCells)
        openWall(currentCell, neighborCells[neighbor])
        addToOpenCells(neighborCells[neighbor],openCells)
        addToMaze( neighborCells[neighbor] )
    else
        table.remove(openCells,pickedCellNumber)
    end




  end
  maze[1][2] = 0
  maze[xMax][yMax-1] = 0




end


function dropBlock(x,y)
  if ( maze[x][y] == 1 ) then
     while ( turtle.getItemCount(selection) <= 0 ) do
       selection = selection + 1
       if ( selection > 16 ) then
         selection = 1
         if ( turtle.getItemCount(selection) <= 0 ) then
           print ("Need more blocks, please put more in!")
           while ( turtle.getItemCount(selection) <= 0 ) do
             os.sleep(10)
           end
         end
       end
       turtle.select(selection)
     end
     turtle.placeDown()


  else
    turtle.digDown()
  end
end

function drawMaze(addFloor)
  local x = 1

  while ( x <= xMax ) do
    local goForward = ( x % 2 == 1 )
    local y
    if ( goForward ) then
      y = 1
    else
      y = yMax
    end

    while ( goForward and y <= yMax ) or ( not goForward and y >= 1 ) do
      dropBlock(x,y)
      tryForward()
      if ( goForward ) then
        y = y + 1
      else
        y = y - 1
      end

    end

    dropBlock(x,y)

    if ( goForward ) then
      turtle.turnLeft()
      tryForward()
      turtle.turnLeft()
    else
      turtle.turnRight()
      tryForward()
      turtle.turnRight()
    end
    tryForward()
    x = x + 1
  end

end

function goHome()
  local i = 1
  while i < yMax do
    tryForward()
    i = i + 1
  end
  i = 1
  turtle.turnLeft()
  while i <= xMax do
    tryForward()
    i = i + 1
  end
  turtle.turnLeft()
  turtle.digUp()
  turtle.up()

end

function coverMaze()
  turtle.turnLeft()
  tryForward()
  turtle.up()
  local y = 1
  while y <= yMax do
    local x = 1
    while x < xMax do
      dropBlock(1,1)
      tryForward()
      x = x + 1
    end

    dropBlock(1,1)
    if ( y % 2 == 0 ) then
      turtle.turnLeft()
      tryForward()
      turtle.turnLeft()
    else
      turtle.turnRight()
      tryForward()
      turtle.turnRight()
    end

    y = y + 1
  end


end

if ( turtle.detectDown() ) then turtle.up() end

initilize(xMax,yMax)
makeMaze()

drawMaze()
goHome()
drawMaze()

if ( #args < 3 or args[3] ~= "-r" ) then
  coverMaze()
end
turtle.down()
turtle.down()
turtle.down()