function love.draw()
  love.graphics.push()
  love.graphics.scale(scale)
  --draw screen
  love.graphics.setColor(1, 1, 1, 1)
  x = 0
  y = 0
  for i = 1, SCREEN_LEN, 1 do
    current_tile = selected_screen:sub(i, i)
    tile_id = 0
    for i, v in ipairs(tiles_char) do
      if v == current_tile then tile_id = i break end
    end
    if tiles[tile_id] then
      love.graphics.draw(tiles[tile_id], x, y)
    end
    x = x + 16
    if x > 16 * 25 then
      x = 0
      y = y + 16
    end
  end
  --draw preview
  love.graphics.setColor(1, 1, 1, 0.5)
  if tiles[selected_tile] then
    love.graphics.draw(tiles[selected_tile], clip_mouse_x, clip_mouse_y)
  end
  --gui
  love.graphics.pop()
  love.graphics.setColor(0.8, 0.8, 0.8, 1)
  love.graphics.print(screen_id, 2, 0)
end