humotion

    double pan, tilt, roll;

    //check if this timestamp allows a valid conversion:

    Timestamp history_begin = joint_interface->get_ts_position(JointInterface::ID_NECK_PAN).get_first_timestamp();

    Timestamp history_end   = joint_interface->get_ts_position(JointInterface::ID_NECK_PAN).get_last_timestamp();

    //printf("> incoming: %f, history is %f to %f\n",relative_target_timestamp.to_seconds(), history_begin.to_seconds(), history_end.to_seconds());

    //our history keeps the last n=100 elements in a timestamped list

    if ((relative_target_timestamp < history_begin) || (history_begin.is_null())){

        //when the incoming data is older than that it makes no sense

        //to do any guesswork and try to calculate a valid absolute target

        //therefore we will use the last known targets (see below)

        //in case we did not see this timestamp before, show a warning:

        if (last_known_absolute_timestamp != relative_target_timestamp){

            printf("> WARNING: restored/guessed absolute target for unknown timestamp %f [this should not happen]\n", relative_target_timestamp.to_seconds());

        }

    }else{

        //all fine, we can reconstruct the absolute target:

        //fetch head / camera pose during that timestamp:

        double neck_pan  = joint_interface->get_ts_position(JointInterface::ID_NECK_PAN).get_interpolated_value(relative_target_timestamp);

        double eye_l_pan = joint_interface->get_ts_position(JointInterface::ID_EYES_LEFT_LR).get_interpolated_value(relative_target_timestamp);

        double eye_r_pan = joint_interface->get_ts_position(JointInterface::ID_EYES_RIGHT_LR).get_interpolated_value(relative_target_timestamp);

        last_known_absolute_target_pan       = neck_pan + (eye_l_pan + eye_r_pan)/2.0;

        //

        double neck_tilt = joint_interface->get_ts_position(JointInterface::ID_NECK_TILT).get_interpolated_value(relative_target_timestamp);

        double eye_tilt  = joint_interface->get_ts_position(JointInterface::ID_EYES_BOTH_UD).get_interpolated_value(relative_target_timestamp);

        last_known_absolute_target_tilt      = neck_tilt + eye_tilt;

        //

        last_known_absolute_target_roll      = joint_interface->get_ts_position(JointInterface::ID_NECK_ROLL).get_interpolated_value(relative_target_timestamp);

        //safe this timestamp as known:

        last_known_absolute_timestamp = relative_target_timestamp;

    }

    pan  = last_known_absolute_target_pan;

    tilt = last_known_absolute_target_tilt;

    roll = last_known_absolute_target_roll;

    pan  -= relative.pan_offset;

    //absolute_gaze.dump();