[CC] Turtle - pont / bridge

--[[
+----------------------------------------------------------------------------+
| Bridge
| version : 2.1
| Auteur : fzed51
| git : https://github.com/fzed51/CC_Script/blob/master/disk/Bridge_2.lua
| pastebin : http://pastebin.com/4DZfqyQ6
+----------------------------------------------------------------------------+
| tag : [lua] [MC] [MineCraft] [CC] [ComputerCraft] [Turtle]
| Descript :
| construit un pont avec des arches.
+----------------------------------------------------------------------------+
]]--

dofile('advTurtle') -- http://pastebin.com/7mLzefhQ

-- inventaire
item.add('coal',1,64)
setFuelItem(item.coal)
item.add('cobblestone',2,64)
item.setup()

--fonctions
local function round(num)
  return math.floor(num + 0.5)
end
local function makePlan( l )
    print("Creation d'un plan pour un pont de "..l.."m.")
    local plan = {}
    -- calcul hauteur max d'un pilier
    local hMax = 63
    if l*2 > hMax then hMax = l*2 end
    -- calcul longueur d'une arche
    local tailles,lArche = {19,18,17,16,15,14,13,12,11,10},0
    local r = tailles[1]
    for _,v in ipairs(tailles) do
        if r < (l-(l%v)) then
            r = (l-(l%v))
            lArche = v
        end
    end
    print('Le pont aura des arches de '..lArche..'m de long.')
    local nbArche = math.ceil(l/lArche)
    for arche = 1, nbArche do
        plan[#plan+1] = hMax
        for position = -1*((lArche-3)/2), ((lArche-3)/2) do
            local pos, rArche =math.abs(position), (lArche-2)/2
            plan[#plan+1] = 2 + ( rArche - round(( rArche^2 - pos^2 )^0.5 ))
        end
        plan[#plan+1] = hMax
    end
    while #plan > l do
        if #plan%2 == 0 then
            table.remove(plan)
        else
            table.remove(plan, 1)
        end
    end
    return plan
end
local function construitSection( epaisseur )
    local alt  = 0
    local dig  = 0
    local stop = false
    while not stop and ( alt > -2 or dig < 2 ) and epaisseur + alt > 0 do
        if turtle.detectDown() then
            dig = dig + 1
        else
            dig = 0
        end
        if tryDown() then
            alt = alt - 1
        else
            stop = true
        end
    end
    while alt < 0 do
        if alt >= -2 then
            turnLeft()
            tryDig()
            tryPlace(item.cobblestone)
            turnBack()
            tryDig()
            tryPlace(item.cobblestone)
            turnLeft()
        end
        tryUp()
        alt = alt + 1
        tryPlaceDown(item.cobblestone)
    end
end
local function countBlock( plan, idx )
    local nbBlock = 0
    if idx == nil or idx > #plan then idx = #plan end
    for i = 1, idx do
        nbBlock = nbBlock + plan[i]
    end
    return nbBlock
end
local function refeelInv( position )
    local p = position
    while p>0 do
        tryForward()
        p=p-1
    end
    print('Rechargez mon inventaire!')
    print('Appuyez sur une touche pour continuer.')
    os.pullEvent('key')
    turnBack()
    while p<position do
        tryForward()
        p=p+1
    end
    turnBack()
end
local function printPlan( p )
    print('Plan pour un pont de '..#p..'m de long.')
    for _, n in ipairs( p ) do
        local nN, sP = n, '##'
        while nN > 0 do
            nN = nN - 1
            sP = sP .. '+'
        end
        print(sP)
    end
end
--main function
local function bridge()
    local longueurPont, plan = 0, {}
    repeat
        tryForward()
        longueurPont = longueurPont + 1
        tryDigUp()
    until turtle.detectDown()
    turnBack()
    local plan = makePlan( longueurPont )
    local nbBlockTotal = countBlock( plan )
    print ('Début de la construction du pont')
    for p = longueurPont, 1, -1 do
        local nbBlock = countBlock( plan, p )
        print ('avancement : '..tostring(round((nbBlockTotal-nbBlock)*100/nbBlockTotal))..'%')
        if itemCount( item.cobblestone ) < (plan[p]+4) then
            refeelInv(p)
        end
        tryForward()
        construitSection(plan[p])
    end
end
--main
term.clear()
term.setCursorPos(1,1)
local head =
[[
                 Bridge v2.0
"""""""""___________________________""""""""""""
""""""""""#########################"""""""""""""
""""""""""" \ /   \ /   \ /   \ / """"""""""""""
"""""""""""""v~~~~~v~~~~~v~~~~~v""""""""""""""""
"""""""""""""~~~~~~~~~~~~~~~~~""""""""""""""""""
]]
term.clear()
term.setCursorPos(1,1)
print (head)
bridge()