Function fromDisjointMeshPieces

source/MRMesh/MRMeshBuilder.cpp:375–425

}

MeshTopology fromDisjointMeshPieces( const Triangulation & t, VertId maxVertId,
    const std::vector<MeshPiece> & pieces,
    const BuildSettings & settings0 )
{
    MR_TIMER;

    // construct empty final mesh with enough number of elements
    const auto numParts = pieces.size();
    std::vector<EdgeId> firstPartEdge( numParts + 1 );
    firstPartEdge[0] = 0_e;
    FaceBitSet region;
    if ( settings0.region )
        region = std::move( *settings0.region );
    region.resize( t.size() );
    for ( int i = 0; i < pieces.size(); ++i )
    {
        const auto & p = pieces[i];
        firstPartEdge[i + 1] = firstPartEdge[i] + (int)p.topology.edgeSize();
        for ( FaceId f : p.rem ) // remaining triangles
            region.set( p.fmap[f] );
    }
    int numEdgesInParts = firstPartEdge.back();

    MeshTopology res;
    const auto borderTriCount = region.count();
    res.edgeReserve( numEdgesInParts + 6 * borderTriCount ); // should be enough even if all border triangles are disconnected
    res.resizeBeforeParallelAdd( numEdgesInParts, maxVertId + 1, t.size() );

    // add pieces in res in parallel
    tbb::parallel_for( tbb::blocked_range<size_t>( 0, numParts, 1 ), [&]( const tbb::blocked_range<size_t> & range )
    {
        assert( range.begin() + 1 == range.end() );
        for ( size_t myPartId = range.begin(); myPartId < range.end(); ++myPartId )
        {
            const auto & part = pieces[myPartId];
            res.addPackedPart( part.topology, firstPartEdge[myPartId], part.fmap, part.vmap );
        }
    } );
    res.computeValidsFromEdges();

    // and add border triangles
    BuildSettings settings = settings0;
    settings.region = &region;
    addTrianglesSeqCore( res, t, settings );
    if ( settings0.skippedFaceCount )
        *settings0.skippedFaceCount = (int)region.count();
    if ( settings0.region )
        *settings0.region = std::move( region );

    return res;
}

constexpr size_t minTrisInPart = 32768;