function update_keyboard()
  --get keys inputs
  --change screen
  local buffer = k_q
  k_q = love.keyboard.isScancodeDown("a")
  if k_q and not buffer and screen_id%100 > 0 then
    save()
    screen_id = screen_id - 1
    load()
  end
  local buffer = k_d
  k_d = love.keyboard.isScancodeDown("d")
  if k_d and not buffer and screen_id%100 < 99 then
    save()
    screen_id = screen_id + 1
    load()
  end
  local buffer = k_z
  k_z = love.keyboard.isScancodeDown("w")
  if k_z and not buffer and screen_id > 99 then
    save()
    screen_id = screen_id - 100
    load()
  end
  local buffer = k_s
  k_s = love.keyboard.isScancodeDown("s")
  if k_s and not buffer and screen_id < 9900 then
    save()
    screen_id = screen_id + 100
    load()
  end
  local buffer = k_i
  k_i = love.keyboard.isScancodeDown("i")
  if k_i and not buffer then
    save()
    screen_id = 5050
    load()
  end
  --swap selected object
  local buffer = k_tab
  k_tab = love.keyboard.isScancodeDown("tab")
  if k_tab and not buffer then
    if love.keyboard.isDown("lshift") then
      selected_tile = selected_tile - 1
      if selected_tile == 0 then selected_tile = #tiles end
    else selected_tile = selected_tile + 1
      if selected_tile > #tiles then selected_tile = 1 end
    end
  end
  --exit
  if love.keyboard.isScancodeDown("escape") then
    save()
    love.event.quit()
  end
  --saving/export
  local buffer = k_c
  k_c = love.keyboard.isDown("c")
  if k_c and not buffer then
    save()
  end
  local buffer = k_o
  k_o = love.keyboard.isDown("o")
  if k_o and not buffer then
    load()
  end
  --scaling
  local buffer = k_k
  k_k = love.keyboard.isDown("k")
  if k_k and not buffer and scale > 1 then
    scale = scale - 1
    love.window.setMode(GAME_WIDTH * scale, GAME_HEIGHT * scale, flags)
  end
  local buffer = k_l
  k_l = love.keyboard.isDown("l")
  if k_l and not buffer and scale < 8 then
    scale = scale + 1
    love.window.setMode(GAME_WIDTH * scale, GAME_HEIGHT * scale, flags)
  end
end