orb_slam3_details/src/Map.cc

/**
* This file is part of ORB-SLAM3
*
* Copyright (C) 2017-2020 Carlos Campos, Richard Elvira, Juan J. Gómez Rodríguez, José M.M. Montiel and Juan D. Tardós, University of Zaragoza.
* Copyright (C) 2014-2016 Raúl Mur-Artal, José M.M. Montiel and Juan D. Tardós, University of Zaragoza.
*
* ORB-SLAM3 is free software: you can redistribute it and/or modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* ORB-SLAM3 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
* the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with ORB-SLAM3.
* If not, see <http://www.gnu.org/licenses/>.
*/


#include "Map.h"

#include<mutex>

namespace ORB_SLAM3
{

long unsigned int Map::nNextId=0;

Map::Map():mnMaxKFid(0),mnBigChangeIdx(0), mbImuInitialized(false), mnMapChange(0), mpFirstRegionKF(static_cast<KeyFrame*>(NULL)),
mbFail(false), mIsInUse(false), mHasTumbnail(false), mbBad(false), mnMapChangeNotified(0), mbIsInertial(false), mbIMU_BA1(false), mbIMU_BA2(false)
{
    mnId=nNextId++;
    mThumbnail = static_cast<GLubyte*>(NULL);
}

Map::Map(int initKFid):mnInitKFid(initKFid), mnMaxKFid(initKFid),mnLastLoopKFid(initKFid), mnBigChangeIdx(0), mIsInUse(false),
                       mHasTumbnail(false), mbBad(false), mbImuInitialized(false), mpFirstRegionKF(static_cast<KeyFrame*>(NULL)),
                       mnMapChange(0), mbFail(false), mnMapChangeNotified(0), mbIsInertial(false), mbIMU_BA1(false), mbIMU_BA2(false)
{
    mnId=nNextId++;
    mThumbnail = static_cast<GLubyte*>(NULL);
}

Map::~Map()
{
    //TODO: erase all points from memory
    mspMapPoints.clear();

    //TODO: erase all keyframes from memory
    mspKeyFrames.clear();

    if(mThumbnail)
        delete mThumbnail;
    mThumbnail = static_cast<GLubyte*>(NULL);

    mvpReferenceMapPoints.clear();
    mvpKeyFrameOrigins.clear();
}
//在地图中插入关键帧,同时更新关键帧的最大id
void Map::AddKeyFrame(KeyFrame *pKF)
{
    unique_lock<mutex> lock(mMutexMap);
    if(mspKeyFrames.empty()){
        cout << "First KF:" << pKF->mnId << "; Map init KF:" << mnInitKFid << endl;
        mnInitKFid = pKF->mnId;
        mpKFinitial = pKF;
        mpKFlowerID = pKF;
    }
    mspKeyFrames.insert(pKF);
    if(pKF->mnId>mnMaxKFid)
    {
        mnMaxKFid=pKF->mnId;
    }
    if(pKF->mnId<mpKFlowerID->mnId)
    {
        mpKFlowerID = pKF;
    }
}

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

void Map::SetImuInitialized()
{
    unique_lock<mutex> lock(mMutexMap);
    mbImuInitialized = true;
}

bool Map::isImuInitialized()
{
    unique_lock<mutex> lock(mMutexMap);
    return mbImuInitialized;
}

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

    //下面是作者加入的注释. 实际上只是从std::set中删除了地图点的指针, 原先地图点
    //占用的内存区域并没有得到释放
    // TODO: This only erase the pointer.
    // Delete the MapPoint
}

void Map::EraseKeyFrame(KeyFrame *pKF)
{
    unique_lock<mutex> lock(mMutexMap);
    mspKeyFrames.erase(pKF);
    if(mspKeyFrames.size()>0)
    {
        if(pKF->mnId == mpKFlowerID->mnId)
        {
            vector<KeyFrame*> vpKFs = vector<KeyFrame*>(mspKeyFrames.begin(),mspKeyFrames.end());
            sort(vpKFs.begin(),vpKFs.end(),KeyFrame::lId);
            mpKFlowerID = vpKFs[0];
        }
    }
    else
    {
        mpKFlowerID = 0;
    }

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

/*
 * @brief 设置参考MapPoints，将用于DrawMapPoints函数画图
 * @param vpMPs Local MapPoints
 */
// 设置参考地图点用于绘图显示局部地图点（红色）
void Map::SetReferenceMapPoints(const vector<MapPoint *> &vpMPs)
{
    unique_lock<mutex> lock(mMutexMap);
    mvpReferenceMapPoints = vpMPs;
}

void Map::InformNewBigChange()
{
    unique_lock<mutex> lock(mMutexMap);
    mnBigChangeIdx++;
}

int Map::GetLastBigChangeIdx()
{
    unique_lock<mutex> lock(mMutexMap);
    return mnBigChangeIdx;
}

//获取地图中的所有关键帧
vector<KeyFrame*> Map::GetAllKeyFrames()
{
    unique_lock<mutex> lock(mMutexMap);
    return vector<KeyFrame*>(mspKeyFrames.begin(),mspKeyFrames.end());
}

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

//获取地图点数目
long unsigned int Map::MapPointsInMap()
{
    unique_lock<mutex> lock(mMutexMap);
    return mspMapPoints.size();
}

//获取地图中的关键帧数目
long unsigned int Map::KeyFramesInMap()
{
    unique_lock<mutex> lock(mMutexMap);
    return mspKeyFrames.size();
}

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

long unsigned int Map::GetId()
{
    return mnId;
}
long unsigned int Map::GetInitKFid()
{
    unique_lock<mutex> lock(mMutexMap);
    return mnInitKFid;
}

void Map::SetInitKFid(long unsigned int initKFif)
{
    unique_lock<mutex> lock(mMutexMap);
    mnInitKFid = initKFif;
}

long unsigned int Map::GetMaxKFid()
{
    unique_lock<mutex> lock(mMutexMap);
    return mnMaxKFid;
}

KeyFrame* Map::GetOriginKF()
{
    return mpKFinitial;
}

void Map::SetCurrentMap()
{
    mIsInUse = true;
}

void Map::SetStoredMap()
{
    mIsInUse = false;
}

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++)
    {
        KeyFrame* pKF = *sit;
        pKF->UpdateMap(static_cast<Map*>(NULL));
//        delete *sit;
    }

    mspMapPoints.clear();
    mspKeyFrames.clear();
    mnMaxKFid = mnInitKFid;
    mnLastLoopKFid = 0;
    mbImuInitialized = false;
    mvpReferenceMapPoints.clear();
    mvpKeyFrameOrigins.clear();
    mbIMU_BA1 = false;
    mbIMU_BA2 = false;
}

bool Map::IsInUse()
{
    return mIsInUse;
}

void Map::SetBad()
{
    mbBad = true;
}

bool Map::IsBad()
{
    return mbBad;
}

void Map::RotateMap(const cv::Mat &R)
{
    unique_lock<mutex> lock(mMutexMap);

    cv::Mat Txw = cv::Mat::eye(4,4,CV_32F);
    R.copyTo(Txw.rowRange(0,3).colRange(0,3));

    KeyFrame* pKFini = mvpKeyFrameOrigins[0];
    cv::Mat Twc_0 = pKFini->GetPoseInverse();
    cv::Mat Txc_0 = Txw*Twc_0;
    cv::Mat Txb_0 = Txc_0*pKFini->mImuCalib.Tcb;
    cv::Mat Tyx = cv::Mat::eye(4,4,CV_32F);
    Tyx.rowRange(0,3).col(3) = -Txb_0.rowRange(0,3).col(3);
    cv::Mat Tyw = Tyx*Txw;
    cv::Mat Ryw = Tyw.rowRange(0,3).colRange(0,3);
    cv::Mat tyw = Tyw.rowRange(0,3).col(3);

    for(set<KeyFrame*>::iterator sit=mspKeyFrames.begin(); sit!=mspKeyFrames.end(); sit++)
    {
        KeyFrame* pKF = *sit;
        cv::Mat Twc = pKF->GetPoseInverse();
        cv::Mat Tyc = Tyw*Twc;
        cv::Mat Tcy = cv::Mat::eye(4,4,CV_32F);
        Tcy.rowRange(0,3).colRange(0,3) = Tyc.rowRange(0,3).colRange(0,3).t();
        Tcy.rowRange(0,3).col(3) = -Tcy.rowRange(0,3).colRange(0,3)*Tyc.rowRange(0,3).col(3);
        pKF->SetPose(Tcy);
        cv::Mat Vw = pKF->GetVelocity();
        pKF->SetVelocity(Ryw*Vw);
    }
    for(set<MapPoint*>::iterator sit=mspMapPoints.begin(); sit!=mspMapPoints.end(); sit++)
    {
        MapPoint* pMP = *sit;
        pMP->SetWorldPos(Ryw*pMP->GetWorldPos()+tyw);
        pMP->UpdateNormalAndDepth();
    }
}

// 恢复尺度及重力方向
/** imu在localmapping中初始化，LocalMapping::InitializeIMU中使用，误差包含三个残差与两个偏置
 * 地图融合时也会使用
 * @param R 初始化时为Rgw
 * @param s 尺度
 * @param bScaledVel 将尺度更新到速度
 * @param t 默认cv::Mat::zeros(cv::Size(1,3),CV_32F)
 */
void Map::ApplyScaledRotation(const cv::Mat &R, const float s, const bool bScaledVel, const cv::Mat t)
{
    unique_lock<mutex> lock(mMutexMap);

    // Body position (IMU) of first keyframe is fixed to (0,0,0)
    cv::Mat Txw = cv::Mat::eye(4,4,CV_32F);
    R.copyTo(Txw.rowRange(0,3).colRange(0,3));

    cv::Mat Tyx = cv::Mat::eye(4,4,CV_32F);

    cv::Mat Tyw = Tyx*Txw;
    Tyw.rowRange(0,3).col(3) = Tyw.rowRange(0,3).col(3)+t;
    // Tyw 中旋转部分等于R，平移部分等于t
    // 做了很多操作，到最后还是得出了一个R跟t？感觉上面的操作像是预留了一些东西，比如在世界坐标系与第一帧有一定Rt时，只不过暂时没有用到
    cv::Mat Ryw = Tyw.rowRange(0,3).colRange(0,3);  // R
    cv::Mat tyw = Tyw.rowRange(0,3).col(3);         // t

    for(set<KeyFrame*>::iterator sit=mspKeyFrames.begin(); sit!=mspKeyFrames.end(); sit++)
    {
        // 更新关键帧位姿
        /**
         * | Rw2w1  tw2w1 |   *   | Rw1c  s*tw1c  |     =    |  Rw2c     s*Rw2w1*tw1c + tw2w1  |
         * |   0      1   |       |  0       1    |          |   0                1            |
         * 这么做比正常乘在旋转上少了个s，后面不需要这个s了，因为所有mp在下面已经全部转到了w2坐标系下，不存在尺度变化了
         * 
         * | s*Rw2w1  tw2w1 |   *   | Rw1c    tw1c  |     =    |  s*Rw2c     s*Rw2w1*tw1c + tw2w1  |
         * |   0        1   |       |  0       1    |          |     0                1            |
         */

        KeyFrame* pKF = *sit;
        cv::Mat Twc = pKF->GetPoseInverse();
        Twc.rowRange(0,3).col(3)*=s;

        // |  Ryc     s*Ryw*twc + tyw  |
        // |   0           1           |
        cv::Mat Tyc = Tyw*Twc;

        cv::Mat Tcy = cv::Mat::eye(4,4,CV_32F);
        Tcy.rowRange(0,3).colRange(0,3) = Tyc.rowRange(0,3).colRange(0,3).t();
        Tcy.rowRange(0,3).col(3) = -Tcy.rowRange(0,3).colRange(0,3)*Tyc.rowRange(0,3).col(3);
        pKF->SetPose(Tcy);
        // 更新关键帧速度
        cv::Mat Vw = pKF->GetVelocity();
        if(!bScaledVel)
            pKF->SetVelocity(Ryw*Vw);
        else
            pKF->SetVelocity(Ryw*Vw*s);

    }
    for(set<MapPoint*>::iterator sit=mspMapPoints.begin(); sit!=mspMapPoints.end(); sit++)
    {
        // 更新每一个mp在世界坐标系下的坐标
        MapPoint* pMP = *sit;
        pMP->SetWorldPos(s*Ryw*pMP->GetWorldPos()+tyw);
        pMP->UpdateNormalAndDepth();
    }
    mnMapChange++;
}

void Map::SetInertialSensor()
{
    unique_lock<mutex> lock(mMutexMap);
    //将mbIsInertial设置为true,将其设置为imu属性,以后的跟踪和预积分将和这个标志有关
    mbIsInertial = true;
}

bool Map::IsInertial()
{
    unique_lock<mutex> lock(mMutexMap);
    return mbIsInertial;
}

void Map::SetIniertialBA1()
{
    unique_lock<mutex> lock(mMutexMap);
    mbIMU_BA1 = true;
}

void Map::SetIniertialBA2()
{
    unique_lock<mutex> lock(mMutexMap);
    mbIMU_BA2 = true;
}

bool Map::GetIniertialBA1()
{
    unique_lock<mutex> lock(mMutexMap);
    return mbIMU_BA1;
}

bool Map::GetIniertialBA2()
{
    unique_lock<mutex> lock(mMutexMap);
    return mbIMU_BA2;
}

void Map::PrintEssentialGraph()
{
    //Print the essential graph
    vector<KeyFrame*> vpOriginKFs = mvpKeyFrameOrigins;
    int count=0;
    cout << "Number of origin KFs: " << vpOriginKFs.size() << endl;
    KeyFrame* pFirstKF;
    for(KeyFrame* pKFi : vpOriginKFs)
    {
        if(!pFirstKF)
            pFirstKF = pKFi;
        else if(!pKFi->GetParent())
            pFirstKF = pKFi;
    }
    if(pFirstKF->GetParent())
    {
        cout << "First KF in the essential graph has a parent, which is not possible" << endl;
    }

    cout << "KF: " << pFirstKF->mnId << endl;
    set<KeyFrame*> spChilds = pFirstKF->GetChilds();
    vector<KeyFrame*> vpChilds;
    vector<string> vstrHeader;
    for(KeyFrame* pKFi : spChilds){
        vstrHeader.push_back("--");
        vpChilds.push_back(pKFi);
    }
    for(int i=0; i<vpChilds.size() && count <= (mspKeyFrames.size()+10); ++i)
    {
        count++;
        string strHeader = vstrHeader[i];
        KeyFrame* pKFi = vpChilds[i];

        cout << strHeader << "KF: " << pKFi->mnId << endl;

        set<KeyFrame*> spKFiChilds = pKFi->GetChilds();
        for(KeyFrame* pKFj : spKFiChilds)
        {
            vpChilds.push_back(pKFj);
            vstrHeader.push_back(strHeader+"--");
        }
    }
    if (count == (mspKeyFrames.size()+10))
        cout << "CYCLE!!"    << endl;

    cout << "------------------" << endl << "End of the essential graph" << endl;
}

bool Map::CheckEssentialGraph(){
    vector<KeyFrame*> vpOriginKFs = mvpKeyFrameOrigins;
    int count=0;
    cout << "Number of origin KFs: " << vpOriginKFs.size() << endl;
    KeyFrame* pFirstKF;
    for(KeyFrame* pKFi : vpOriginKFs)
    {
        if(!pFirstKF)
            pFirstKF = pKFi;
        else if(!pKFi->GetParent())
            pFirstKF = pKFi;
    }
    cout << "Checking if the first KF has parent" << endl;
    if(pFirstKF->GetParent())
    {
        cout << "First KF in the essential graph has a parent, which is not possible" << endl;
    }

    set<KeyFrame*> spChilds = pFirstKF->GetChilds();
    vector<KeyFrame*> vpChilds;
    vpChilds.reserve(mspKeyFrames.size());
    for(KeyFrame* pKFi : spChilds)
        vpChilds.push_back(pKFi);

    for(int i=0; i<vpChilds.size() && count <= (mspKeyFrames.size()+10); ++i)
    {
        count++;
        KeyFrame* pKFi = vpChilds[i];
        set<KeyFrame*> spKFiChilds = pKFi->GetChilds();
        for(KeyFrame* pKFj : spKFiChilds)
            vpChilds.push_back(pKFj);
    }

    cout << "count/tot" << count << "/" << mspKeyFrames.size() << endl;
    if (count != (mspKeyFrames.size()-1))
        return false;
    else
        return true;
}

void Map::ChangeId(long unsigned int nId)
{
    mnId = nId;
}

unsigned int Map::GetLowerKFID()
{
    unique_lock<mutex> lock(mMutexMap);
    if (mpKFlowerID) {
        return mpKFlowerID->mnId;
    }
    return 0;
}

int Map::GetMapChangeIndex()
{
    unique_lock<mutex> lock(mMutexMap);
    return mnMapChange;
}

void Map::IncreaseChangeIndex()
{
    unique_lock<mutex> lock(mMutexMap);
    mnMapChange++;
}

int Map::GetLastMapChange()
{
    unique_lock<mutex> lock(mMutexMap);
    return mnMapChangeNotified;
}

void Map::SetLastMapChange(int currentChangeId)
{
    unique_lock<mutex> lock(mMutexMap);
    mnMapChangeNotified = currentChangeId;
}


} //namespace ORB_SLAM3