code: def draw_overlay(self, surf):
      
      obs = self._obs.observation
      player = obs.player_common
      surf.write_screen(
          self._font_large, colors.green, (0.2, 0.2),
          "Minerals: %s, Vespene: %s, Food: %s / %s" % (
              player.minerals, player.vespene, player.food_used, player.food_cap))
      times, steps = zip(*self._game_times)
      sec = obs.game_loop // 22.4  # http://liquipedia.net/starcraft2/Game_Speed
      surf.write_screen(
          self._font_large, colors.green, (-0.2, 0.2),
          "Score: %s, Step: %s, %.1f/s, Time: %d:%02d" % (
              obs.score.score, obs.game_loop, sum(steps) / (sum(times) or 1),
              sec // 60, sec % 60),
          align="right")
      surf.write_screen(
          self._font_large, colors.green * 0.8, (-0.2, 1.2),
          "FPS: O:%.1f, R:%.1f" % (
              len(times) / (sum(times) or 1),
              len(self._render_times) / (sum(self._render_times) or 1)),
          align="right")
      line = 3
      for alert, ts in sorted(self._alerts.items(), key=lambda item: item[1]):
        if time.time() < ts + 3:  # Show for 3 seconds.
          surf.write_screen(self._font_large, colors.red, (20, line), alert)
          line += 1
        else:
          del self._alerts[alert]
docs: Draw the overlay describing resources.