手把手带你死磕ORBSLAM3源代码(九）System.h代码分析

目录

一.前言

二.System.h代码分析

2.1代码调用

2.2 Verbose类

?2.3 声明类

2.4System类

一.前言

System库是orbslam3直接调用的库，内部调用了众多其它库。

二.System.h代码分析

2.1代码调用

#ifndef SYSTEM_H
#define SYSTEM_H


#include <unistd.h>
#include<stdio.h>
#include<stdlib.h>
#include<string>
#include<thread>
#include<opencv2/core/core.hpp>

#include "Tracking.h"
#include "FrameDrawer.h"
#include "MapDrawer.h"
#include "Atlas.h"
#include "LocalMapping.h"
#include "LoopClosing.h"
#include "KeyFrameDatabase.h"
#include "ORBVocabulary.h"
#include "Viewer.h"
#include "ImuTypes.h"
#include "Settings.h"

在这里调用了其他的代码文件，并引入必要的库文件。

2.2 Verbose类

class Verbose
{
public:
    enum eLevel
    {
        VERBOSITY_QUIET=0,
        VERBOSITY_NORMAL=1,
        VERBOSITY_VERBOSE=2,
        VERBOSITY_VERY_VERBOSE=3,
        VERBOSITY_DEBUG=4
    };

    static eLevel th;

public:
    static void PrintMess(std::string str, eLevel lev)
    {
        if(lev <= th)
            cout << str << endl;
    }

    static void SetTh(eLevel _th)
    {
        th = _th;
    }
};

这是一个名为Verbose的C++类，它的目的是管理日志或输出的详细程度。下面是这段代码的逐行解释：

1. class Verbose: 声明一个名为Verbose的类。
2. {: 类的开始。
3. public:: 下面的成员是公开的，意味着从类的外部也可以访问它们。
4. enum eLevel: 声明一个名为eLevel的枚举类型。这个枚举用于表示不同的详细程度或日志级别。
5. {: 枚举的开始。
6. VERBOSITY_QUIET=0,: 表示"安静"模式，不输出任何日志。
7. VERBOSITY_NORMAL=1,: 表示"正常"模式，输出基本的日志信息。
8. VERBOSITY_VERBOSE=2,: 表示"详细"模式，输出更多的日志信息。
9. VERBOSITY_VERY_VERBOSE=3,: 表示"非常详细"模式，输出大量的日志信息。
10. VERBOSITY_DEBUG=4: 表示"调试"模式，输出所有的日志信息，通常用于调试目的。
11. };: 枚举的结束。
12. static eLevel th;: 声明一个静态的eLevel类型的变量th。这个变量表示当前的日志级别阈值。只有级别低于或等于这个阈值的日志才会被输出。因为它是静态的，所以这个变量在类的所有实例之间共享。
13. public:: 下面的成员函数是公开的，意味着从类的外部也可以调用它们。
14. static void PrintMess(std::string str, eLevel lev): 声明一个静态成员函数PrintMess，它接受一个字符串和一个eLevel枚举值作为参数。这个函数用于打印消息，但只有在消息的级别低于或等于当前阈值时才会打印。
15. {: 函数体的开始。
16. if(lev <= th): 检查传入的日志级别是否低于或等于当前的阈值。
17. cout << str << endl;: 如果上面的条件为真，则输出传入的字符串并在其后加一个换行符。
18. }: 函数体的结束。
19. static void SetTh(eLevel _th): 声明另一个静态成员函数SetTh，它接受一个eLevel枚举值作为参数。这个函数用于设置新的阈值。
20. {: 函数体的开始。
21. th = _th;: 设置新的阈值。
22. }: 函数体的结束。
23. };: 类的结束。

?2.3 声明类

class Viewer;
class FrameDrawer;
class MapDrawer;
class Atlas;
class Tracking;
class LocalMapping;
class LoopClosing;
class Settings;

通过这些语句实现对其他文件调用的类的声明。

2.4System类

class System
{
public:
    // Input sensor
    enum eSensor{
        MONOCULAR=0,
        STEREO=1,
        RGBD=2,
        IMU_MONOCULAR=3,
        IMU_STEREO=4,
        IMU_RGBD=5,
    };

    // File type
    enum FileType{
        TEXT_FILE=0,
        BINARY_FILE=1,
    };

public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW
    // Initialize the SLAM system. It launches the Local Mapping, Loop Closing and Viewer threads.
    System(const string &strVocFile, const string &strSettingsFile, const eSensor sensor, const bool bUseViewer = true, const int initFr = 0, const string &strSequence = std::string());

    // Proccess the given stereo frame. Images must be synchronized and rectified.
    // Input images: RGB (CV_8UC3) or grayscale (CV_8U). RGB is converted to grayscale.
    // Returns the camera pose (empty if tracking fails).
    Sophus::SE3f TrackStereo(const cv::Mat &imLeft, const cv::Mat &imRight, const double &timestamp, const vector<IMU::Point>& vImuMeas = vector<IMU::Point>(), string filename="");

    // Process the given rgbd frame. Depthmap must be registered to the RGB frame.
    // Input image: RGB (CV_8UC3) or grayscale (CV_8U). RGB is converted to grayscale.
    // Input depthmap: Float (CV_32F).
    // Returns the camera pose (empty if tracking fails).
    Sophus::SE3f TrackRGBD(const cv::Mat &im, const cv::Mat &depthmap, const double &timestamp, const vector<IMU::Point>& vImuMeas = vector<IMU::Point>(), string filename="");

    // Proccess the given monocular frame and optionally imu data
    // Input images: RGB (CV_8UC3) or grayscale (CV_8U). RGB is converted to grayscale.
    // Returns the camera pose (empty if tracking fails).
    Sophus::SE3f TrackMonocular(const cv::Mat &im, const double &timestamp, const vector<IMU::Point>& vImuMeas = vector<IMU::Point>(), string filename="");


    // This stops local mapping thread (map building) and performs only camera tracking.
    void ActivateLocalizationMode();
    // This resumes local mapping thread and performs SLAM again.
    void DeactivateLocalizationMode();

    // Returns true if there have been a big map change (loop closure, global BA)
    // since last call to this function
    bool MapChanged();

    // Reset the system (clear Atlas or the active map)
    void Reset();
    void ResetActiveMap();

    // All threads will be requested to finish.
    // It waits until all threads have finished.
    // This function must be called before saving the trajectory.
    void Shutdown();
    bool isShutDown();

    // Save camera trajectory in the TUM RGB-D dataset format.
    // Only for stereo and RGB-D. This method does not work for monocular.
    // Call first Shutdown()
    // See format details at: http://vision.in.tum.de/data/datasets/rgbd-dataset
    void SaveTrajectoryTUM(const string &filename);

    // Save keyframe poses in the TUM RGB-D dataset format.
    // This method works for all sensor input.
    // Call first Shutdown()
    // See format details at: http://vision.in.tum.de/data/datasets/rgbd-dataset
    void SaveKeyFrameTrajectoryTUM(const string &filename);

    void SaveTrajectoryEuRoC(const string &filename);
    void SaveKeyFrameTrajectoryEuRoC(const string &filename);

    void SaveTrajectoryEuRoC(const string &filename, Map* pMap);
    void SaveKeyFrameTrajectoryEuRoC(const string &filename, Map* pMap);

    // Save data used for initialization debug
    void SaveDebugData(const int &iniIdx);

    // Save camera trajectory in the KITTI dataset format.
    // Only for stereo and RGB-D. This method does not work for monocular.
    // Call first Shutdown()
    // See format details at: http://www.cvlibs.net/datasets/kitti/eval_odometry.php
    void SaveTrajectoryKITTI(const string &filename);

    // TODO: Save/Load functions
    // SaveMap(const string &filename);
    // LoadMap(const string &filename);

    // Information from most recent processed frame
    // You can call this right after TrackMonocular (or stereo or RGBD)
    int GetTrackingState();
    std::vector<MapPoint*> GetTrackedMapPoints();
    std::vector<cv::KeyPoint> GetTrackedKeyPointsUn();

    // For debugging
    double GetTimeFromIMUInit();
    bool isLost();
    bool isFinished();

    void ChangeDataset();

    float GetImageScale();

#ifdef REGISTER_TIMES
    void InsertRectTime(double& time);
    void InsertResizeTime(double& time);
    void InsertTrackTime(double& time);
#endif

private:

    void SaveAtlas(int type);
    bool LoadAtlas(int type);

    string CalculateCheckSum(string filename, int type);

    // Input sensor
    eSensor mSensor;

    // ORB vocabulary used for place recognition and feature matching.
    ORBVocabulary* mpVocabulary;

    // KeyFrame database for place recognition (relocalization and loop detection).
    KeyFrameDatabase* mpKeyFrameDatabase;

    // Map structure that stores the pointers to all KeyFrames and MapPoints.
    //Map* mpMap;
    Atlas* mpAtlas;

    // Tracker. It receives a frame and computes the associated camera pose.
    // It also decides when to insert a new keyframe, create some new MapPoints and
    // performs relocalization if tracking fails.
    Tracking* mpTracker;

    // Local Mapper. It manages the local map and performs local bundle adjustment.
    LocalMapping* mpLocalMapper;

    // Loop Closer. It searches loops with every new keyframe. If there is a loop it performs
    // a pose graph optimization and full bundle adjustment (in a new thread) afterwards.
    LoopClosing* mpLoopCloser;

    // The viewer draws the map and the current camera pose. It uses Pangolin.
    Viewer* mpViewer;

    FrameDrawer* mpFrameDrawer;
    MapDrawer* mpMapDrawer;

    // System threads: Local Mapping, Loop Closing, Viewer.
    // The Tracking thread "lives" in the main execution thread that creates the System object.
    std::thread* mptLocalMapping;
    std::thread* mptLoopClosing;
    std::thread* mptViewer;

    // Reset flag
    std::mutex mMutexReset;
    bool mbReset;
    bool mbResetActiveMap;

    // Change mode flags
    std::mutex mMutexMode;
    bool mbActivateLocalizationMode;
    bool mbDeactivateLocalizationMode;

    // Shutdown flag
    bool mbShutDown;

    // Tracking state
    int mTrackingState;
    std::vector<MapPoint*> mTrackedMapPoints;
    std::vector<cv::KeyPoint> mTrackedKeyPointsUn;
    std::mutex mMutexState;

    //
    string mStrLoadAtlasFromFile;
    string mStrSaveAtlasToFile;

    string mStrVocabularyFilePath;

    Settings* settings_;
};

这部分代码声明了System.cc中System类的各个函数。