Function reducePath

source/MRMesh/MRReducePath.cpp:566–724

}

int reducePath( const Mesh & mesh, const MeshTriPoint & start, SurfacePath & path, const MeshTriPoint & end, int maxIter )
{
    if ( maxIter <= 0 )
        return 0;
    MR_TIMER;

    // consider points on degenerate edges as points in vertices
    for ( auto & e : path )
    {
        if ( !e.inVertex() && mesh.edgeLengthSq( e.e ) <= 0 )
        {
            e.a = 0;
            assert( e.inVertex() );
        }
    }

    SurfacePath newPath;
    newPath.reserve( path.size() );
    SurfacePath cacheOneSideUnfold;
    std::vector<Vector2f> tmp;
    std::vector<std::pair<int,int>> vertSpans;
    SurfacePath rpoints; // to be added next in the new path in reverse order
    tbb::enumerable_thread_specific<TriangleStripUnfolder> stripPerThread( std::cref( mesh ) );
    for ( int i = 0; i < maxIter; ++i )
    {
        std::atomic<bool> pathTopologyChanged{false};

        // try to exit from vertices and remove repeating locations
        int j = 0;
        // there are points to add in newPath
        auto hasNext = [&]()
        {
            return !rpoints.empty() || j < path.size();
        };
        // returns next point to add in newPath, if extract=false then it will be returned again next time
        auto takeNext = [&]( bool extract )
        {
            MeshEdgePoint res;
            if ( !rpoints.empty() )
            {
                res = rpoints.back();
                if ( extract )
                    rpoints.pop_back();
            }
            else
            {
                res = path[j];
                if ( extract )
                    ++j;
            }
            return res;
        };
        // remove last point from newPath and mark topology as changed
        auto newPathPopBack = [&]()
        {
            newPath.pop_back();
            pathTopologyChanged.store( true, std::memory_order_relaxed );
        };