obstacle_heuristic.hpp

// Copyright (c) 2026, Open Navigation LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License. Reserved.
 
#ifndef NAV2_SMAC_PLANNER__OBSTACLE_HEURISTIC_HPP_
#define NAV2_SMAC_PLANNER__OBSTACLE_HEURISTIC_HPP_
 
#include <utility>
#include <vector>
#include <memory>
#include "nav2_smac_planner/constants.hpp"
#include "nav2_smac_planner/types.hpp"
#include "nav2_costmap_2d/costmap_2d_ros.hpp"
 
namespace nav2_smac_planner
{
 
typedef std::pair<float, uint64_t> ObstacleHeuristicElement;
struct ObstacleHeuristicComparator
{
  bool operator()(const ObstacleHeuristicElement & a, const ObstacleHeuristicElement & b) const
  {
    return a.first > b.first;
  }
};
 
typedef std::vector<ObstacleHeuristicElement> ObstacleHeuristicQueue;
 
class ObstacleHeuristic
{
public:
  ObstacleHeuristic() {}
 
  ~ObstacleHeuristic() {}
 
  void resetObstacleHeuristic(
    std::shared_ptr<nav2_costmap_2d::Costmap2DROS> costmap_ros_i,
    const unsigned int & start_x, const unsigned int & start_y,
    const unsigned int & goal_x, const unsigned int & goal_y,
    const bool downsample_obstacle_heuristic);
 
  float getObstacleHeuristic(
    const Coordinates & node_coords,
    const float & cost_penalty,
    const bool use_quadratic_cost_penalty,
    const bool downsample_obstacle_heuristic);
 
  inline float distanceHeuristic2D(
    const uint64_t idx, const unsigned int size_x,
    const unsigned int target_x, const unsigned int target_y)
  {
    int dx = static_cast<int>(idx % size_x) - static_cast<int>(target_x);
    int dy = static_cast<int>(idx / size_x) - static_cast<int>(target_y);
    return std::sqrt(dx * dx + dy * dy);
  }
 
protected:
  LookupTable obstacle_heuristic_lookup_table_;
  ObstacleHeuristicQueue obstacle_heuristic_queue_;
  std::shared_ptr<nav2_costmap_2d::Costmap2DROS> costmap_ros;
};
 
}  // namespace nav2_smac_planner
 
#endif  // NAV2_SMAC_PLANNER__OBSTACLE_HEURISTIC_HPP_