turtleSpikes.lua

maxSize = 27
edgeGap = 2
midGap = 5

math.randomseed(os.time())
grid = {}

-- set up basic grid values
for x = 1,maxSize do
    grid[x] = {}
    for y = 1,maxSize do
        if (x <= edgeGap) or (y <= edgeGap) or (x > maxSize-edgeGap) or (y > maxSize-edgeGap) then
            grid[x][y] = math.random(0,2)
        elseif (x <= midGap) or (y <= midGap) or (x > maxSize-midGap) or (y > maxSize-midGap) then
            grid[x][y] = math.random(0,4)
        else
            len1 = math.random(0,11)
            len2 = math.random(0,11)
            if len1 < len2 then
                grid[x][y] = len1
            else
                grid[x][y] = len2
            end
        end
    end
end

-- create edging around longer spikes
for x = 1,maxSize do
    for y = 1,maxSize do
        if grid[x][y] >= 9 then
            if grid[x-1][y] < (grid[x][y] - 2) then
                grid[x-1][y] = math.random((grid[x][y]-5),(grid[x][y]-2))
            end
            if grid[x+1][y] < (grid[x][y] - 2) then
                grid[x+1][y] = math.random((grid[x][y]-5),(grid[x][y]-2))
            end
            if grid[x][y-1] < (grid[x][y] - 2) then
                grid[x][y-1] = math.random((grid[x][y]-5),(grid[x][y]-2))
            end
            if grid[x][y+1] < (grid[x][y] - 2) then
                grid[x][y+1] = math.random((grid[x][y]-5),(grid[x][y]-2))
            end
            --[[
            for xo = -1,1,1 do
                for yo = -1,1,1 do
                    if grid[x+xo][y] < (grid[x][y] - 2) then
                        grid[x+xo][y] = math.random((grid[x][y]-5),(grid[x][y]-2))
                    elseif grid[x][y+yo] < (grid[x][y] - 2) then
                        grid[x][y+yo] = math.random((grid[x][y]-5),(grid[x][y]-2))
                    end
                end
            end
            --]]
        end
    end
end

function invCheck()
    empty = true
    for i=1,16 do
        if turtle.getItemCount(i) > 0 then
            empty = false
            break
        end
    end
    if empty then
        print("Waiting for blocks, press enter when refilled.")
        read()
    end
end

function selectBlock()
    slot = math.random(16)
    turtle.select(slot)
    while turtle.getItemCount(slot) == 0 do
        slot = slot + 1
        if slot == 17 then slot = 1 end
        turtle.select(slot)
    end
end

function placeUp()
    invCheck()
    selectBlock()
    turtle.placeUp()
end

function placeSpike(length)
    if not turtle.detectUp() then -- don't start a spike where the island doesn't exist above
        return false
    elseif length == 0 then -- 0 length, do nothing
        return false
    else
        for i = 1,length do
            turtle.down()
            placeUp()
        end
        return true
    end
end

function displayGrid()
    mon = peripheral.wrap("right")
    mon.setTextScale(.5)
    mon.clear()
    for x=1,maxSize do
        for y=1,maxSize do
            os.sleep(.1)
            mon.setTextColor(colors.white)
            mon.setCursorPos(x*2,y)
            if grid[x][y] == 11 then
                mon.setTextColor(colors.red)
                mon.write(".")
            elseif grid[x][y] == 10 then
                mon.setTextColor(colors.red)
                mon.write("X")
            else
                if grid[x][y] == 9 then
                    mon.setTextColor(colors.red)
                elseif grid[x][y] >= 6 then
                    mon.setTextColor(colors.orange)
                elseif grid[x][y] <= 2 then
                    mon.setTextColor(colors.lightBlue)
                end
                mon.write(tostring(grid[x][y]))
            end
        end
    end
end

function build()
    for x=1,maxSize do
        for y=1,maxSize do
            length = grid[x][y]
            if x%2 == 0 then -- turtle runs a zigzag, reverse Y on every other row
                length = grid[x][maxSize-y+1]
            end
            placed = placeSpike(length)
            turtle.forward()
            if placed then
                for i=1,length do
                    turtle.up()
                end
            end
        end
        if x%2 == 0 then
            turtle.turnLeft()
            turtle.forward()
            turtle.turnLeft()
            turtle.forward()
        else
            turtle.turnRight()
            turtle.forward()
            turtle.turnRight()
            turtle.forward()
        end
    end
end

build()