Method FlowAggregator

source/MRMesh/MRAggregateFlow.cpp:13–50

{

FlowAggregator::FlowAggregator( const Mesh & mesh, const VertScalars & heights ) : mesh_( mesh ), heights_( heights )
{
    MR_TIMER;
    downFlowVert_.resize( mesh.topology.vertSize() );
    downPath_.resize( mesh.topology.vertSize() );
    BitSetParallelFor( mesh.topology.getValidVerts(), [&]( VertId v )
    {
        if ( mesh.topology.isBdVertex( v ) )
            return;
        const EdgePoint p0( mesh.topology, v );
        VertId nextVert;
        EdgePoint bdPoint;
        downPath_[v] = computeSteepestDescentPath( mesh, heights, p0, { .outVertexReached = &nextVert, .outBdReached = &bdPoint } );
        if ( bdPoint )
            downPath_[v].push_back( bdPoint );
        downFlowVert_[v] = nextVert;
    } );

    rootVert_.resize( mesh.topology.vertSize() );
    BitSetParallelFor( mesh.topology.getValidVerts(), [&]( VertId v )
    {
        auto root = v;
        while ( auto n = downFlowVert_[root] )
            root = n;
        rootVert_[v] = root;
    } );

    using MinusHeightVert = std::pair<float, VertId>;
    std::vector<MinusHeightVert> minusHeightVerts;
    minusHeightVerts.reserve( mesh.topology.numValidVerts() );
    for ( auto v : mesh.topology.getValidVerts() )
        minusHeightVerts.push_back( { -heights[v], v } );
    tbb::parallel_sort( minusHeightVerts.begin(), minusHeightVerts.end() );

    vertsSortedDesc_.reserve( minusHeightVerts.size() );
    for ( size_t i = 0; i < minusHeightVerts.size(); ++i )
        vertsSortedDesc_.push_back( minusHeightVerts[i].second );
}

VertScalars FlowAggregator::computeFlow( const std::vector<FlowOrigin> & starts, const OutputFlows & out ) const
{