class Scene_Map
  alias abs_main main
  alias abs_update update
  def main
    $abs.main
    abs_main
  def update
    abs_update
    $abs.update
  end
end

class ABS
  def main
  end
  def update
    Keyboard.update
    Mouse.update
    if Keyboard.trigger?(Keyboard::Mouse_Left)
      p Mouse.position
    end
  end
end

$abs = ABS.new