Shard spawner room (Potato Craft)

local mon = peripheral.wrap("top")
mon.setTextScale(1)
mon.setTextColor(colors.white)
local button={}
mon.setBackgroundColor(colors.black)

function setTable(name, func, xmin, xmax, ymin, ymax)
   button[name] = {}
   button[name]["func"] = func
   button[name]["active"] = false
   button[name]["xmin"] = xmin
   button[name]["ymin"] = ymin
   button[name]["xmax"] = xmax
   button[name]["ymax"] = ymax
end

function skeleClick(state)
  print(state)
  redstone.setOutput("right",state)
end

function zombClick(state)
  print(state)
  redstone.setOutput("left",state)
end

function fillTable()
   setTable("Skeleton", skeleClick, 2, 28, 3, 9)
   setTable("Zombie", zombClick, 2, 28, 12, 18)
end

function fill(text, color, bData)
   mon.setBackgroundColor(color)
   local yspot = math.floor((bData["ymin"] + bData["ymax"]) /2)
   local xspot = math.floor((bData["xmax"] - bData["xmin"] - string.len(text)) /2) +1
   for j = bData["ymin"], bData["ymax"] do
      mon.setCursorPos(bData["xmin"], j)
      if j == yspot then
         for k = 0, bData["xmax"] - bData["xmin"] - string.len(text) +1 do
            if k == xspot then
               mon.write(text)
            else
               mon.write(" ")
            end
         end
      else
         for i = bData["xmin"], bData["xmax"] do
            mon.write(" ")
         end
      end
   end
   mon.setBackgroundColor(colors.black)
end

function screen()
   local currColor
   for name,data in pairs(button) do
      local on = data["active"]
      if on == true then currColor = colors.lime else currColor = colors.red end
      fill(name, currColor, data)
   end
end

function checkxy(x, y)
   for name, data in pairs(button) do
      if y>=data["ymin"] and  y <= data["ymax"] then
         if x>=data["xmin"] and x<= data["xmax"] then
            data["active"] = not data["active"]
            data["func"](data["active"])
         end
      end
   end
end

function center(line,text)
   w, h = mon.getSize()
   mon.setCursorPos((w-string.len(text))/2+1, line)
   mon.write(text)
end

fillTable()
skeleClick(false)
zombClick(false)
while true do
   mon.clear()
   center(1,"Spawner On/Off")
   screen()
   local e,side,x,y = os.pullEvent()
   if e == "redstone" then
    sleep(0.25)
    if redstone.getInput("bottom") == false then
      skeleClick(false)
      zombClick(false)
      button["Skeleton"]["active"] = false
      button["Zombie"]["active"] = false
    end
   elseif e == "monitor_touch" then
    checkxy(x,y)
   else
    sleep(0.9)
   end
   sleep(0.1)
end