Maze

currentSlot = 1
location=vector.new(1,0)
dir=0
tArgs={...}
if #tArgs<1 then
print("Usage: mazegen <width> [length]")
return
end
width=tonumber(tArgs[1])
height=tonumber(tArgs[2]) or width
print("Making maze ",width,"x",height)
cells={}

for i=0,width+1 do
 cells[i]={}
 for j=0,height+1 do
  cells[i][j]={visited=true,parent=vector.new(),pos=vector.new(i,j),finish=false}
 end
end

for i=1,width do
for j=1,height do
 cells[i][j].visited=false
end
end

cells[width][height+1].finish=true
cells[width][height+1].visited=false

function go(goto)
 local goDir=goto-location
 local tardir=0
 if goDir.x>0 then
  tardir=1
 elseif goDir.x<0 then
  tardir=3
 end
 if goDir.y>0 then
  tardir=0
 elseif goDir.y<0 then
  tardir=2
 end
 while dir~=tardir do
  turtle.turnRight()
  dir=(dir+1)%4
 end
 -- print(tardir)
 safeMove()
 cells[goto.x][goto.y].visited=true
 location=goto
end
function safeMove()
  while turtle.detect() and not turtle.dig() do
    turtle.attack()
  end
  while not turtle.forward() do
    turtle.dig()
    turtle.attack()
  end
  turtle.digUp()
  while turtle.detectDown() and not turtle.digDown() do
    turtle.attackDown()
  end
  safePlace()
  while turtle.detect() and not turtle.dig() do
    turtle.attack()
  end
  while not turtle.forward() do
    turtle.dig()
    turtle.attack()
  end
  turtle.digUp()
  while turtle.detectDown() and not turtle.digDown() do
    turtle.attackDown()
  end
  safePlace()
end
function selectSlot()
  while turtle.getItemCount(currentSlot) < 2 do
    currentSlot = currentSlot + 1
    if currentSlot == 15 then
      currentSlot = 1
      sleep(1)
    end
  end
  turtle.select(currentSlot)
end
function safePlace()
  selectSlot()
  turtle.placeDown()
end
function mazegen(nextpoint)
 cells[nextpoint.x][nextpoint.y].parent=location
 print("Moving forward")
 go(nextpoint)
 if cells[location.x][location.y].finish==true then
  turtle.placeUp()
  print("Found finish")
 else
  local neighbours={cells[nextpoint.x-1][nextpoint.y],cells[nextpoint.x+1][nextpoint.y],cells[nextpoint.x][nextpoint.y-1],cells[nextpoint.x][nextpoint.y+1]}
  local unvisited={}
  for i,v in ipairs(neighbours) do
   if v.visited==false then
    table.insert(unvisited,v)
   end
  end
  while #unvisited>0 do
   local randomnum=math.random(1,#unvisited)
   if cells[unvisited[randomnum].pos.x][unvisited[randomnum].pos.y].visited==false then
    print("New branch at "..tostring(unvisited[randomnum].pos))
    mazegen(unvisited[randomnum].pos)
   end
   table.remove(unvisited,randomnum)
   print(#unvisited .." left")
  end
 end
 print("Backtracking to "..tostring(cells[location.x][location.y].parent))
 go(cells[location.x][location.y].parent)
end

mazegen(vector.new(1,1))
turtle.turnRight()
turtle.turnRight()