CC: Treefarm - farm.lua

local farmWidth -- number
local farmLength -- number
local farmSpacing -- number, blocks between each tree

local farmField -- table

local farmXOffset -- number
local farmYOffset -- number
local farmZOffset -- number

-- gets all global variables
function init( global )
    setfenv(1,global)
end

function distance( x1,z1,x2,z2 )
    local dx = x1-x2
    local dz = z1-z2
    return math.sqrt(dx^2+dz^2)
end

function findNearestSpot( x,z )
    local nearX,nearZ = x,z
    local nearestDistance = math.huge
    local turtleX,_,turtleZ = gps.getPosition()
    local direction
    -- direction is from the nearest position towards the x,z

    for xOffset = -1,1 do
        for zOffset = -1,1 do
            if (xOffset==0 or zOffset==0) and zOffset~=xOffset then

                -- distance from the turtle to the tree
                local tmpDistance = distance(x+xOffset,z+zOffset,turtleX,turtleZ)
                if tmpDistance < nearestDistance then
                    nearX = x + xOffset
                    nearZ = z + zOffset
                    nearestDistance = tmpDistance

                    if xOffset == 1 then
                        direction = gps.west
                    elseif xOffset == -1 then
                        direction = gps.east
                    elseif zOffset == 1 then
                        direction = gps.north
                    elseif zOffset == -1 then
                        direction = gps.south
                    end
                end

            end
        end
    end

    return nearX,nearZ,direction
end

function findNearestCorner( x1,z1,x2,z2 )
    local nearX,nearZ
    local nearestDistance = math.huge
    local turtleX,_,turtleZ = gps.getPosition()

    for x = x1,x2,x2-x1 do
        for z = z1,z2,z2-z1 do

            -- distance from the turtle to the corner
            local tmpDistance = distance(x,z,turtleX,turtleZ)
            if tmpDistance < nearestDistance then
                nearX = x
                nearZ = z
                nearestDistance = tmpDistance
            end

        end
    end

    return nearX,nearZ
end

-- will dig til it reaches the surface
-- instead of comparing log
-- more consistant and easier with a big farm
-- This does move the turtle 1 block forward
function chop( clearDirt,x,z )
    if not x or not z then
        x,_,z = gps.getPosition(1,gps.absPos.dir)
    end
    gps.moveForward(1,killMobs,true)
    if turtle.detectUp() then
        -- tree in front

        -- begin chop down the tree
        -- keep count on the trees height
        local height = 0
        while turtle.detectUp() do
            gps.moveUp(1,killMobs,true)
            height = height + 1
        end

        -- get back down to the "ground"
        gps.moveDown(height,killMobs,true)
    else
        -- no tree in front
    end
    if clearDirt then
        dig.down(killMobs,true)
    end
end

function chopAll( clearDirt )
    if type(farmWidth) == "number"
    and type(farmLength) == "number"
    and type(farmSpacing) == "number"
    and type(farmXOffset) == "number"
    and type(farmYOffset) == "number"
    and type(farmZOffset) == "number"
    then

        -- find nearest corner of farm

        local homeX,homeY,homeZ = gps.getHome()

        local corner1x = homeX + farmXOffset
        local corner1z = homeZ + farmZOffset
        local corner2x = homeX + farmXOffset + (farmWidth-mult(farmWidth)) * farmSpacing
        local corner2z = homeZ + farmZOffset + (farmLength-mult(farmLength)) * farmSpacing

        -- loop through the trees
        local startX,startZ = findNearestCorner( corner1x,corner1z,corner2x,corner2z )
        local stopX = corner1x; if stopX==startX then stopX = corner2x end
        local stopZ = corner1z; if stopZ==startZ then stopZ = corner2z end

        for x = startX,stopX,farmSpacing*mult(stopX-startX) do
            -- to alternate so you zig zag through the farm to save fuel and time
            local iteration = (x-startX+farmSpacing)/farmSpacing
            local A,B = startZ,stopZ
            if iteration%2==0 then A,B = stopZ,startZ end
            --print("i="..iteration.." start at "..A.." stop at "..B)
            for z = A,B,farmSpacing*mult(B-A) do
                --write(z.." ")
                local treeX,treeZ,dir = findNearestSpot(x,z)
                gps.goto(treeX,homeY+farmYOffset,treeZ,dir)
                chop(clearDirt)
            end
            --print()
        end
    end
end

-- requires dirt
function replant()
    if type(farmWidth) == "number"
    and type(farmLength) == "number"
    and type(farmSpacing) == "number"
    and type(farmXOffset) == "number"
    and type(farmYOffset) == "number"
    and type(farmZOffset) == "number"
    then

        -- obtain materials
        item.followStoragePath()
        item.dropoff()
        item.getItems({item.types.dirt,item.types.sapling},math.abs(farmWidth*farmLength),true)
        item.followStoragePath(true)

        -- find nearest corner of farm

        local homeX,homeY,homeZ = gps.getHome()

        local corner1x = homeX + farmXOffset
        local corner1z = homeZ + farmZOffset
        local corner2x = homeX + farmXOffset + (farmWidth-mult(farmWidth)) * farmSpacing
        local corner2z = homeZ + farmZOffset + (farmLength-mult(farmLength)) * farmSpacing

        -- loop through the trees
        local startX,startZ = findNearestCorner( corner1x,corner1z,corner2x,corner2z )
        local stopX = corner1x; if stopX==startX then stopX = corner2x end
        local stopZ = corner1z; if stopZ==startZ then stopZ = corner2z end

        for x = startX,stopX,farmSpacing*mult(stopX-startX) do
            -- to alternate so you zig zag through the farm to save fuel and time
            local iteration = (x-startX+farmSpacing)/farmSpacing
            local A,B = startZ,stopZ
            if iteration%2==0 then A,B = stopZ,startZ end
            --print("i="..iteration.." start at "..A.." stop at "..B)
            for z = A,B,farmSpacing*mult(B-A) do

                -- select dirt
                local atStorage = false
                while not item.select(item.types.dirt) do
                    if not atStorage then item.followStoragePath() atStorage=true end
                    item.getItem(item.types.dirt,_,false)
                end
                if atStorage then item.followStoragePath(true) end

                gps.goto(x,homeY+farmYOffset,z)
                turtle.placeDown()

                -- select sapling
                local atStorage = false
                while not item.select(item.types.sapling) do
                    if not atStorage then item.followStoragePath() atStorage=true end
                    item.getItem(item.types.sapling,_,false)
                end
                if atStorage then item.followStoragePath(true) end

                gps.goto(x,homeY+farmYOffset+1,z)
                turtle.placeDown()
            end
        end
    end

    item.followStoragePath()
    item.dropoff()
    gps.goto(gps.getHome())
end

function setOffset( xOffset,yOffset,zOffset )
    farmXOffset = xOffset or farmXOffset
    farmYOffset = yOffset or farmYOffset
    farmZOffset = zOffset or farmZOffset
end

function setSize( width,length,spacing )
    farmWidth = width or farmWidth
    farmLength = length or farmLength
    farmSpacing = spacing or farmSpacing
end

-- sets the field forwards to the right
-- z = forward
-- x = right
-- state = (boolean) true/false depends if its grown/harvested
function updateField( state )
    if type(farmWidth) == "number"
    and type(farmLength) == "number"
    and type(farmSpacing) == "number"
    and type(farmZOffset) == "number"
    and type(farmXOffset) == "number"
    then
        -- reset the field
        farmField = {}

        local totalWidth = (farmWidth-1) * farmSpacing + 1
        local totalLength = (farmLength-1) * farmSpacing + 1

        -- loop through the width and length
        for x = 1,totalWidth,farmSpacing do
            for z = 1,totalLength,farmSpacing do
                -- make sure the column exists
                if not farmField[x] then farmField[x] = {} end

                farmField[x][z] = farmField[x][z] or (state or false)
            end
        end

        return true
    else
        return false
    end
end