Anvil Dropping Player

local difficulty
local player = 2
local monitorSide = "back"
local modemSide = "bottom"
local running = true
local xpos, ypos
--Arrays Cooresponding to position of buttons on monitor
--16 Difficulties, P1 Ready, P2 Ready, X to Reboot
local xd = {8, 14, 20, 26, 8, 14, 20, 26, 8, 14, 20, 26, 8, 14, 20, 26, 8, 23, 33}
local yd = {7, 7, 7, 7, 10, 10, 10, 10, 13, 13, 13, 13, 16, 16, 16, 16, 20, 20, 2}
--Color (decimal) of Difficulty when printed
local difficultyState = {}
--Color of playerOne
local playerOne = 1
--Color of playerTwo
local playerTwo = 1
--Menu State and Table of Run Fuctions
local menuState = "difficulty"
local mopt = {
    ["difficulty"] = {draw = drawDifficulty, changer = changeDifficulty},
    ["ready"] = {draw = drawReady, changer = changeReady}
    }



--Monitor Setup
m = peripheral.wrap(monitorSide)
m.setTextScale(0.5)
local wm,hm = m.getSize()

function aSum(array,int)
    arraySum = 0
    for i=1,int do
        arraySum = arraySum + array[i]
    end
    return arraySum
end

function round(num, idp)
  local mult = 10^(idp or 0)
  return math.floor(num * mult + 0.5) / mult
end

function monitorCentered(str,ypos)
    m.setCursorPos(wm/2 - #str/2, ypos)
    m.write(str)
end

function monitorRight(str,ypos)
    m.setCursorPos(wm - #str, ypos)
    m.write(str)
end

function monitorLeft(str,ypos)
    m.setCursorPos(1 , ypos)
    m.write(str)
end

function drawMonitorBG(title)
    m.clear()
    m.setTextColor(colors.gray)
    monitorCentered(string.rep("-",wm),1)
    m.setTextColor(colors.lightGray)
    monitorCentered(title, 2)
    m.setTextColor(colors.gray)
    monitorCentered(string.rep("-",wm),3)
    monitorLeft("|",2)
    monitorRight("|",2)
        local th = 4
    for th=4,hm-1 do
        monitorLeft("|",th)
        monitorRight("|",th)
    end
    monitorCentered(string.rep("-",wm),hm)
    m.setTextColor(colors.red)
    m.setCursorPos(wm-3,2)
    m.write("X")
end

function drawDifficulty()
    for i=1,16 do
    m.setTextColor(difficultyState[i])
    m.setCursorPos(xd[i], yd[i])
    m.write(tostring(i))
    end

    m.setTextColor(playerOne)
    m.setCursorPos(8,20)
    m.write("1P Ready")
    m.setTextColor(playerTwo)
    m.setCursorPos(20,20)
    m.write("2P Ready")
end

function changeDifficulty()

    --For difficulty selection
    for i=1,16 do
        local xMax, xMin, yMax, yMin
        xMax = xd[i] + 2
        xMin = xd[i] - 2
        yMax = yd[i] + 1
        yMin = yd[i] - 1
        if xpos >= xMin and xpos <= xMax and ypos >= yMin and ypos <= yMax then
            --Resets Difficulty Colors
            for j=1,16 do
                difficultyState[j] = 1
            end
            difficulty=i
            --Makes active choice orange
            difficultyState[i] = 2
            --Locks Door...lol
            rednet.broadcast("S"..player)
        end
    end

    --For bottom buttons
    for i=17,18 do
        local xMax, xMin, yMax, yMin
        xMax = xd[i] + 5
        xMin = xd[i] - 5
        yMax = yd[i] + 1
        yMin = yd[i] - 1
        if xpos >= xMin and xpos <= xMax and ypos >= yMin and ypos <= yMax and aSum(difficultyState,16)==17 then
            if i == 17 then
                playerOne = 2
                playerTwo = 1
                print("ready p1")
                rednet.broadcast("D"..difficulty)
                rednet.broadcast("P1")
            end
            if i == 18 then
                playerOne = 1
                playerTwo = 2
                print("ready p2")
                rednet.broadcast("D"..difficulty)
                rednet.broadcast("P2")
            end
            --Locks Door...lol
            rednet.broadcast("S"..player)
        end
    end

    --To reboot
    local xMax, xMin, yMax, yMin
    xMax = xd[19] + 1
    xMin = xd[19] - 1
    yMax = yd[19] + 1
    yMin = yd[19] - 1
    if xpos >= xMin and xpos <= xMax and ypos >= yMin and ypos <= yMax then
        os.reboot()
    end

end


--Initialization

--Open Rednet
rednet.open(modemSide)
--Broadcasts Signal to Unlock forcefield if locked
rednet.broadcast("N"..player)

--Background Black
m.setBackgroundColor(colors.black)
--Resets Difficulty Array
for i=1,16 do
    difficultyState[i] = 1
end
--Extend for touchscreen




--Draws Initial Page
drawMonitorBG("Select Difficulty")
drawDifficulty()





--Operation
while running do
    event, a, xpos, ypos = os.pullEvent()
    if event == "monitor_touch" then
            --Push Red X in Top Right to Reboot System
            if (xpos == 33 and ypos == 2) then
                os.reboot()
            end
            changeDifficulty()
            drawDifficulty()
    end
    if event == "rednet_message" then
        if xpos == "reboot" then
        os.reboot()
        end
    end
end