bool transformGlobalPlan(const tf::TransformListener& tf, const std::vector<geometry_msgs::PoseStamped>& global_plan, 
						const costmap_2d::Costmap2DROS& costmap, const std::string& global_frame, 
						std::vector<geometry_msgs::PoseStamped>& transformed_plan, std::vector<int>& start_end_counts)
{
	const geometry_msgs::PoseStamped& plan_pose = global_plan[0];

	// initiate refernce variables
	transformed_plan.clear();

	try
	{
		if (!global_plan.size() > 0)
		{
			ROS_ERROR("Recieved plan with zero length");
			return false;
		}

		tf::StampedTransform transform;
		tf.lookupTransform(global_frame, ros::Time(), plan_pose.header.frame_id, plan_pose.header.stamp, 
							plan_pose.header.frame_id, transform);

		//let's get the pose of the robot in the frame of the plan
		tf::Stamped<tf::Pose> robot_pose;
		robot_pose.setIdentity();
		robot_pose.frame_id_ = costmap.getBaseFrameID();
		robot_pose.stamp_ = ros::Time();
		tf.transformPose(plan_pose.header.frame_id, robot_pose, robot_pose);

		//we'll keep points on the plan that are within the window that we're looking at
		double dist_threshold = std::max(costmap.getSizeInCellsX() * costmap.getResolution() / 2.0, costmap.getSizeInCellsY() * costmap.getResolution() / 2.0);

		unsigned int i = 0;
		double sq_dist_threshold = dist_threshold * dist_threshold;
		double sq_dist = DBL_MAX;

		// --- start - modification w.r.t. base_local_planner
		// initiate start_end_count
		std::vector<int> start_end_count;
		start_end_count.assign(2, 0);

		// we know only one direction and that is forward! - initiate search with previous start_end_counts
		// this is neccesserry to work with the sampling based planners - path may severall time enter and leave moving window
		ROS_ASSERT( (start_end_counts.at(0) > 0) && (start_end_counts.at(0) <= (int) global_plan.size()) );
		i = (unsigned int) global_plan.size() - (unsigned int) start_end_counts.at(0);
		// --- end - modification w.r.t. base_local_planner

		//we need to loop to a point on the plan that is within a certain distance of the robot
		while(i < (unsigned int)global_plan.size() && sq_dist > sq_dist_threshold)
		{
			double x_diff = robot_pose.getOrigin().x() - global_plan[i].pose.position.x;
			double y_diff = robot_pose.getOrigin().y() - global_plan[i].pose.position.y;
			sq_dist = x_diff * x_diff + y_diff * y_diff;

			// --- start - modification w.r.t. base_local_planner
			// not yet in reach - get next frame
			if( sq_dist > sq_dist_threshold )
				++i;
			else
				// set counter for start of transformed intervall - from back as beginning of plan might be prunned
				start_end_count.at(0) = (int) (((unsigned int) global_plan.size()) - i);
			// --- end - modification w.r.t. base_local_planner
		}


		tf::Stamped<tf::Pose> tf_pose;
		geometry_msgs::PoseStamped newer_pose;

		//now we'll transform until points are outside of our distance threshold
		while(i < (unsigned int)global_plan.size() && sq_dist < sq_dist_threshold)
		{
			double x_diff = robot_pose.getOrigin().x() - global_plan[i].pose.position.x;
			double y_diff = robot_pose.getOrigin().y() - global_plan[i].pose.position.y;
			sq_dist = x_diff * x_diff + y_diff * y_diff;

			const geometry_msgs::PoseStamped& pose = global_plan[i];
			poseStampedMsgToTF(pose, tf_pose);
			tf_pose.setData(transform * tf_pose);
			tf_pose.stamp_ = transform.stamp_;
			tf_pose.frame_id_ = global_frame;
			poseStampedTFToMsg(tf_pose, newer_pose);

			transformed_plan.push_back(newer_pose);

			// --- start - modification w.r.t. base_local_planner
			// set counter for end of transformed intervall - from back as beginning of plan might be prunned
			start_end_count.at(1) = int (((unsigned int) global_plan.size()) - i);
			// --- end - modification w.r.t. base_local_planner

			++i;
		}

		// --- start - modification w.r.t. base_local_planner
		// write to reference variable
		start_end_counts = start_end_count;
		// --- end - modification w.r.t. base_local_planner
    }
	catch(tf::LookupException& ex)
	{
		ROS_ERROR("No Transform available Error: %s\n", ex.what());
		return false;
	}
	catch(tf::ConnectivityException& ex)
	{
		ROS_ERROR("Connectivity Error: %s\n", ex.what());
		return false;
	}
	catch(tf::ExtrapolationException& ex)
	{
		ROS_ERROR("Extrapolation Error: %s\n", ex.what());
		if (global_plan.size() > 0)
			ROS_ERROR("Global Frame: %s Plan Frame size %d: %s\n", global_frame.c_str(), (unsigned int)global_plan.size(), global_plan[0].header.frame_id.c_str());

		return false;
	}

	return true;
}
bool transformGlobalPlan(const tf::TransformListener& tf, const std::vector<geometry_msgs::PoseStamped>& global_plan,
                         const costmap_2d::Costmap2DROS& costmap, const std::string& global_frame,
                         std::vector<geometry_msgs::PoseStamped>& transformed_plan) {
    const geometry_msgs::PoseStamped& plan_pose = global_plan[0];

    transformed_plan.clear();

    try {
        if (!global_plan.size() > 0)
        {
            ROS_ERROR("Recieved plan with zero length");
            return false;
        }

        tf::StampedTransform transform;
        tf.lookupTransform(global_frame, ros::Time(),
                           plan_pose.header.frame_id, plan_pose.header.stamp,
                           plan_pose.header.frame_id, transform);

        //let's get the pose of the robot in the frame of the plan
        tf::Stamped<tf::Pose> robot_pose;
        robot_pose.setIdentity();
        robot_pose.frame_id_ = costmap.getBaseFrameID();
        robot_pose.stamp_ = ros::Time();
        tf.transformPose(plan_pose.header.frame_id, robot_pose, robot_pose);

        //we'll keep points on the plan that are within the window that we're looking at
        double dist_threshold = std::max(costmap.getSizeInCellsX() * costmap.getResolution() / 2.0, costmap.getSizeInCellsY() * costmap.getResolution() / 2.0);

        unsigned int i = 0;
        double sq_dist_threshold = dist_threshold * dist_threshold;
        double sq_dist = DBL_MAX;

        //we need to loop to a point on the plan that is within a certain distance of the robot
        while(i < (unsigned int)global_plan.size() && sq_dist > sq_dist_threshold) {
            double x_diff = robot_pose.getOrigin().x() - global_plan[i].pose.position.x;
            double y_diff = robot_pose.getOrigin().y() - global_plan[i].pose.position.y;
            sq_dist = x_diff * x_diff + y_diff * y_diff;
            ++i;
        }

        //make sure not to count the first point that is too far away
        if(i > 0)
            --i;

        tf::Stamped<tf::Pose> tf_pose;
        geometry_msgs::PoseStamped newer_pose;

        //now we'll transform until points are outside of our distance threshold
        while(i < (unsigned int)global_plan.size() && sq_dist < sq_dist_threshold) {
            double x_diff = robot_pose.getOrigin().x() - global_plan[i].pose.position.x;
            double y_diff = robot_pose.getOrigin().y() - global_plan[i].pose.position.y;
            sq_dist = x_diff * x_diff + y_diff * y_diff;

            const geometry_msgs::PoseStamped& pose = global_plan[i];
            poseStampedMsgToTF(pose, tf_pose);
            tf_pose.setData(transform * tf_pose);
            tf_pose.stamp_ = transform.stamp_;
            tf_pose.frame_id_ = global_frame;
            poseStampedTFToMsg(tf_pose, newer_pose);

            transformed_plan.push_back(newer_pose);

            ++i;
        }
    }
    catch(tf::LookupException& ex) {
        ROS_ERROR("No Transform available Error: %s\n", ex.what());
        return false;
    }
    catch(tf::ConnectivityException& ex) {
        ROS_ERROR("Connectivity Error: %s\n", ex.what());
        return false;
    }
    catch(tf::ExtrapolationException& ex) {
        ROS_ERROR("Extrapolation Error: %s\n", ex.what());
        if (global_plan.size() > 0)
            ROS_ERROR("Global Frame: %s Plan Frame size %d: %s\n", global_frame.c_str(), (unsigned int)global_plan.size(), global_plan[0].header.frame_id.c_str());

        return false;
    }

    return true;
}