costmap_2d/include/robot_costmap_2d/inflation_layer.h

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 * Author: Eitan Marder-Eppstein
 *         David V. Lu!!
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#ifndef ROBOT_COSTMAP_2D_INFLATION_LAYER_H_
#define ROBOT_COSTMAP_2D_INFLATION_LAYER_H_

#include <robot_costmap_2d/layer.h>
#include <robot_costmap_2d/layered_costmap.h>
#include <boost/thread.hpp>

namespace robot_costmap_2d
{
/**
 * @class CellData
 * @brief Storage for cell information used during obstacle inflation
 */
class CellData
{
public:
  /**
   * @brief  Constructor for a CellData objects
   * @param  i The index of the cell in the cost map
   * @param  x The x coordinate of the cell in the cost map
   * @param  y The y coordinate of the cell in the cost map
   * @param  sx The x coordinate of the closest obstacle cell in the costmap
   * @param  sy The y coordinate of the closest obstacle cell in the costmap
   * @return
   */
  CellData(double i, unsigned int x, unsigned int y, unsigned int sx, unsigned int sy) :
      index_(i), x_(x), y_(y), src_x_(sx), src_y_(sy)
  {
  }
  unsigned int index_;
  unsigned int x_, y_;
  unsigned int src_x_, src_y_;
};

class InflationLayer : public Layer
{
public:
  InflationLayer();

  virtual ~InflationLayer()
  {
    deleteKernels();
    if (seen_)
        delete[] seen_;
  }

  virtual void onInitialize();
  virtual void updateBounds(double robot_x, double robot_y, double robot_yaw, double* min_x, double* min_y,
                            double* max_x, double* max_y);
  virtual void updateCosts(robot_costmap_2d::Costmap2D& master_grid, int min_i, int min_j, int max_i, int max_j);
  virtual bool isDiscretized()
  {
    return true;
  }
  virtual void matchSize();

  virtual void reset() { onInitialize(); }

  /** @brief  Given a distance, compute a cost.
   * @param  distance The distance from an obstacle in cells
   * @return A cost value for the distance */
  virtual inline unsigned char computeCost(double distance) const
  {
    unsigned char cost = 0;
    if (distance == 0)
      cost = LETHAL_OBSTACLE;
    else if (distance * resolution_ <= inscribed_radius_)
      cost = INSCRIBED_INFLATED_OBSTACLE;
    else
    {
      // make sure cost falls off by Euclidean distance
      double euclidean_distance = distance * resolution_;
      double factor = exp(-1.0 * weight_ * (euclidean_distance - inscribed_radius_));
      cost = (unsigned char)((INSCRIBED_INFLATED_OBSTACLE - 1) * factor);
    }
    return cost;
  }

  /**
   * @brief Change the values of the inflation radius parameters
   * @param inflation_radius The new inflation radius
   * @param cost_scaling_factor The new weight
   */
  void setInflationParameters(double inflation_radius, double cost_scaling_factor);

protected:
  virtual void onFootprintChanged();
  boost::recursive_mutex* inflation_access_;

  double resolution_;
  double inflation_radius_;
  double inscribed_radius_;
  double weight_;
  bool inflate_unknown_;

private:
  void handleImpl(const void* data,
                  const std::type_info& info,
                  const std::string& source) override;
  /**
   * @brief  Lookup pre-computed distances
   * @param mx The x coordinate of the current cell
   * @param my The y coordinate of the current cell
   * @param src_x The x coordinate of the source cell
   * @param src_y The y coordinate of the source cell
   * @return
   */
  inline double distanceLookup(int mx, int my, int src_x, int src_y)
  {
    unsigned int dx = abs(mx - src_x);
    unsigned int dy = abs(my - src_y);
    return cached_distances_[dx][dy];
  }

  /**
   * @brief  Lookup pre-computed costs
   * @param mx The x coordinate of the current cell
   * @param my The y coordinate of the current cell
   * @param src_x The x coordinate of the source cell
   * @param src_y The y coordinate of the source cell
   * @return
   */
  inline unsigned char costLookup(int mx, int my, int src_x, int src_y)
  {
    unsigned int dx = abs(mx - src_x);
    unsigned int dy = abs(my - src_y);
    return cached_costs_[dx][dy];
  }

  void computeCaches();
  void deleteKernels();
  void inflate_area(int min_i, int min_j, int max_i, int max_j, unsigned char* master_grid);

  unsigned int cellDistance(double world_dist)
  {
    return layered_costmap_->getCostmap()->cellDistance(world_dist);
  }

  inline void enqueue(unsigned int index, unsigned int mx, unsigned int my,
                      unsigned int src_x, unsigned int src_y);

  unsigned int cell_inflation_radius_;
  unsigned int cached_cell_inflation_radius_;
  std::map<double, std::vector<CellData> > inflation_cells_;

  bool* seen_;
  int seen_size_;

  unsigned char** cached_costs_;
  double** cached_distances_;
  double last_min_x_, last_min_y_, last_max_x_, last_max_y_;

  bool getParams(const std::string& config_file_name, robot::NodeHandle &nh);

  bool need_reinflation_;  ///< Indicates that the entire costmap should be reinflated next time around.
};

}  // namespace robot_costmap_2d

#endif  // ROBOT_COSTMAP_2D_INFLATION_LAYER_H_