给下列程序添加注释namespace nav_core { /** * @class BaseGlobalPlanner * @brief Provides an interface for global planners used in navigation. All global planners written as plugins for the navigation stack must adhere to this interface. */ class BaseGlobalPlanner{ public: /** * @brief Given a goal pose in the world, compute a plan * @param start The start pose * @param goal The goal pose * @param plan The plan... filled by the planner * @return True if a valid plan was found, false otherwise */ virtual bool makePlan(const geometry_msgs::PoseStamped& start, const geometry_msgs::PoseStamped& goal, std::vector<geometry_msgs::PoseStamped>& plan) = 0; /** * @brief Given a goal pose in the world, compute a plan * @param start The start pose * @param goal The goal pose * @param plan The plan... filled by the planner * @param cost The plans calculated cost * @return True if a valid plan was found, false otherwise */ virtual bool makePlan(const geometry_msgs::PoseStamped& start, const geometry_msgs::PoseStamped& goal, std::vector<geometry_msgs::PoseStamped>& plan, double& cost) { cost = 0; return makePlan(start, goal, plan); } /** * @brief Initialization function for the BaseGlobalPlanner * @param name The name of this planner * @param costmap_ros A pointer to the ROS wrapper of the costmap to use for planning */ virtual void initialize(std::string name, costmap_2d::Costmap2DROS* costmap_ros) = 0; /** * @brief Virtual destructor for the interface */ virtual ~BaseGlobalPlanner(){} protected: BaseGlobalPlanner(){} }; }; // namespace nav_core #endif // NAV_CORE_BASE_GLOBAL_PLANNER_H

namespace nav_core {

/** 
 * @class BaseGlobalPlanner
 * @brief Provides an interface for global planners used in navigation. All global planners written as plugins for the navigation stack must adhere to this interface.
 */
class BaseGlobalPlanner{
 public:

  /** 
   * @brief Given a goal pose in the world, compute a plan
   * @param start The start pose 
   * @param goal The goal pose 
   * @param plan The plan... filled by the planner
   * @return True if a valid plan was found, false otherwise
   */
  virtual bool makePlan(const geometry_msgs::PoseStamped& start,
      const geometry_msgs::PoseStamped& goal, std::vector<geometry_msgs::PoseStamped>& plan) = 0;

  /** 
   * @brief Given a goal pose in the world, compute a plan
   * @param start The start pose 
   * @param goal The goal pose 
   * @param plan The plan... filled by the planner
   * @param cost The plans calculated cost
   * @return True if a valid plan was found, false otherwise
   */
  virtual bool makePlan(const geometry_msgs::PoseStamped& start,
                        const geometry_msgs::PoseStamped& goal, std::vector<geometry_msgs::PoseStamped>& plan,
                        double& cost)
  {
    cost = 0;
    return makePlan(start, goal, plan);
  }

  /** 
   * @brief  Initialization function for the BaseGlobalPlanner
   * @param  name The name of this planner
   * @param  costmap_ros A pointer to the ROS wrapper of the costmap to use for planning
   */
  virtual void initialize(std::string name, costmap_2d::Costmap2DROS* costmap_ros) = 0;

  /** 
   * @brief  Virtual destructor for the interface
   */
  virtual ~BaseGlobalPlanner(){}

 protected:
  BaseGlobalPlanner(){}
};

}; // namespace nav_core

#endif // NAV_CORE_BASE_GLOBAL_PLANNER_H

这是一个名称空间为`nav_core`的C++程序。它定义了一个名为`BaseGlobalPlanner`的类，这个类是一个抽象类，提供用于导航中使用的全局计划器的接口。所有针对导航堆栈编写的全局计划器插件都必须遵循这个接口。

这个类有三个公共函数：

- `makePlan`：给定世界中的目标姿态，计算一个计划。
- `initialize`：初始化函数，用于设置计划器的名称和代价地图。
- 析构函数：用于销毁实例。

其中，`makePlan`函数有两个版本，其中一个版本还返回计划的代价。这个类还提供了一个保护构造函数，用于派生类的构造。