while(True):
    clock.tick()
    img = sensor.snapshot()
    tags = sorted(img.find_apriltags(fx=f_x, fy=f_y, cx=c_x, cy=c_y), key = lambda x: x.w() * x.h(), reverse = True)

    if tags and (tags[0].id() in valid_tag_ids):
        if MAX_DISTANCE_SENSOR_enable: send_distance_sensor_packet(tags[0], valid_tag_ids[tags[0].id()])
        send_landing_target_packet(tags[0], img.width(), img.height(), valid_tag_ids[tags[0].id()])
        img.draw_rectangle(tags[0].rect(),(255,0,0))
        img.draw_cross(tags[0].cx(), tags[0].cy(),(255,0,0))
        print("Distance %f m - FPS %f" % (z_to_mm(tags[0].z_translation(), valid_tag_ids[tags[0].id()])/1000, clock.fps()))
    else:
        print("FPS %f" % clock.fps())