该函数用于判断一个地图点是否落在当前帧的视锥内、是否值得参与局部地图匹配，并顺带填充跟踪所需的投影坐标、尺度层级、视角余弦等缓存数据。bool Frame::isInFrustum(MapPoint *pMP, float viewingCosLimit) { if(Nleft == -1){ pMP-mbTrackInView = false; pMP-mTrackProjX = -1; pMP-mTrackProjY = -1; // 3D in absolute coordinates Eigen::Matrixfloat,3,1 P = pMP-GetWorldPos(); // 3D in camera coordinates const Eigen::Matrixfloat,3,1 Pc = mRcw * P + mtcw; const float Pc_dist = Pc.norm(); // Check positive depth const float PcZ = Pc(2); const float invz = 1.0f/PcZ; if(PcZ0.0f) return false; const Eigen::Vector2f uv = mpCamera-project(Pc); if(uv(0)mnMinX ||