ORB-SLAM2的源码阅读（四）：Map类

这个类别算是比较简单，主要是负责维护其中关键帧和地图点，就是后面要讲的几类。包括设置参考地
4000
图点用于绘制地图。还有一些计数和保存地图点，关键帧ID的功能。

#ifndef MAP_H
#define MAP_H

#include "MapPoint.h"
#include "KeyFrame.h"
#include <set>

#include <mutex>

namespace ORB_SLAM2
{

class MapPoint;
class KeyFrame;

class Map
{
public:
Map();

void AddKeyFrame(KeyFrame* pKF);
void AddMapPoint(MapPoint* pMP);
void EraseMapPoint(MapPoint* pMP);
void EraseKeyFrame(KeyFrame* pKF);
void SetReferenceMapPoints(const std::vector<MapPoint*> &vpMPs);
void InformNewBigChange();
int GetLastBigChangeIdx();

std::vector<KeyFrame*> GetAllKeyFrames();
std::vector<MapPoint*> GetAllMapPoints();
std::vector<MapPoint*> GetReferenceMapPoints();

long unsigned int MapPointsInMap();
long unsigned  KeyFramesInMap();

long unsigned int GetMaxKFid();

void clear();

vector<KeyFrame*> mvpKeyFrameOrigins;

std::mutex mMutexMapUpdate;

// This avoid that two points are created simultaneously in separate threads (id conflict)
std::mutex mMutexPointCreation;

protected:
std::set<MapPoint*> mspMapPoints;
std::set<KeyFrame*> mspKeyFrames;

std::vector<MapPoint*> mvpReferenceMapPoints;

long unsigned int mnMaxKFid;

// Index related to a big change in the map (loop closure, global BA)
int mnBigChangeIdx;

std::mutex mMutexMap;
};

} //namespace ORB_SLAM

#endif // MAP_H

如果看具体代码实现，其实基本上都是unique_lock的操作

#include "Map.h"

#include<mutex>

namespace ORB_SLAM2
{

//构造函数
Map::Map():mnMaxKFid(0),mnBigChangeIdx(0)
{
}

//增加关键帧
void Map::AddKeyFrame(KeyFrame *pKF)
{
unique_lock<mutex> lock(mMutexMap);
mspKeyFrames.insert(pKF);
if(pKF->mnId>mnMaxKFid)
mnMaxKFid=pKF->mnId;
}

//增加地图点
void Map::AddMapPoint(MapPoint *pMP)
{
unique_lock<mutex> lock(mMutexMap);
mspMapPoints.insert(pMP);
}

//擦除地图点
void Map::EraseMapPoint(MapPoint *pMP)
{
unique_lock<mutex> lock(mMutexMap);
mspMapPoints.erase(pMP);

// TODO: This only erase the pointer.
// Delete the MapPoint
}

//擦除关键帧
void Map::EraseKeyFrame(KeyFrame *pKF)
{
unique_lock<mutex> lock(mMutexMap);
mspKeyFrames.erase(pKF);

// TODO: This only erase the pointer.
// Delete the MapPoint
}

//设置参考地图点
void Map::SetReferenceMapPoints(const vector<MapPoint *> &vpMPs)
{
unique_lock<mutex> lock(mMutexMap);
mvpReferenceMapPoints = vpMPs;
}

// 关于新变化的ID
void Map::InformNewBigChange()
{
unique_lock<mutex> lock(mMutexMap);
mnBigChangeIdx++;
}

//最后变动的ID
int Map::GetLastBigChangeIdx()
{
unique_lock<mutex> lock(mMutexMap);
return mnBigChangeIdx;
}

//得到所有关键帧
vector<KeyFrame*> Map::GetAllKeyFrames()
{
unique_lock<mutex> lock(mMutexMap);
return vector<KeyFrame*>(mspKeyFrames.begin(),mspKeyFrames.end());
}

//得到所有地图点
vector<MapPoint*> Map::GetAllMapPoints()
{
unique_lock<mutex> lock(mMutexMap);
return vector<MapPoint*>(mspMapPoints.begin(),mspMapPoints.end());
}

//返回现在地图中含有的地图点的个数
long unsigned int Map::MapPointsInMap()
{
unique_lock<mutex> lock(mMutexMap);
return mspMapPoints.size();
}

//返回地图中关键帧的个数
long unsigned int Map::KeyFramesInMap()
{
unique_lock<mutex> lock(mMutexMap);
return mspKeyFrames.size();
}

//得到参考地图点
vector<MapPoint*> Map::GetReferenceMapPoints()
{
unique_lock<mutex> lock(mMutexMap);
return mvpReferenceMapPoints;
}

//得到最大关键帧ID
long unsigned int Map::GetMaxKFid()
{
unique_lock<mutex> lock(mMutexMap);
return mnMaxKFid;
}

//清除所有地图
void Map::clear()
{
for(set<MapPoint*>::iterator sit=mspMapPoints.begin(), send=mspMapPoints.end(); sit!=send; sit++)
delete *sit;

for(set<KeyFrame*>::iterator sit=mspKeyFrames.begin(), send=mspKeyFrames.end(); sit!=send; sit++)
delete *sit;

mspMapPoints.clear();
mspKeyFrames.clear();
mnMaxKFid = 0;
mvpReferenceMapPoints.clear();
mvpKeyFrameOrigins.clear();
}

} //namespace ORB_SLAM

O(∩_∩)O哈哈~