Function expandToComponents

source/MRMesh/MRMeshComponents.cpp:231–293

}

Expected<FaceBitSet> expandToComponents( const MeshPart& mp, const FaceBitSet& seeds, const ExpandToComponentsParams& params /*= {} */ )
{
    if ( params.coverRatio > 1.0f )
        return FaceBitSet();
    if ( params.coverRatio <= 0.0f )
        return getComponents( mp, seeds, params.incidence, params.isCompBd );

    MR_TIMER;

    auto res = seeds;
    auto compMapRes = MeshComponents::getAllComponentsMap( mp, params.incidence, params.isCompBd );
    const auto& compMap = compMapRes.first;
    int numComps = compMapRes.second;

    if ( !reportProgress( params.cb, 0.3f ) )
        return unexpectedOperationCanceled();

    RegionBitSet compsWithSeeds( numComps );
    for ( auto f : res )
        compsWithSeeds.set( compMap[f] );

    if ( !reportProgress( params.cb, 0.6f ) )
        return unexpectedOperationCanceled();

    const auto& region = mp.mesh.topology.getFaceIds( mp.region );

    struct AreaCounter
    {
        float seedArea = 0.0f;
        float totalArea = 0.0f;
    };
    Vector<AreaCounter, RegionId> areas( numComps );
    for ( auto f : region )
    {
        auto rId = compMap[f];
        if ( !compsWithSeeds.test( rId ) )
            continue;
        auto area = mp.mesh.area( f );
        areas[rId].totalArea += area;
        if ( res.test( f ) )
            areas[rId].seedArea += area;
    }

    if ( !reportProgress( params.cb, 0.9f ) )
        return unexpectedOperationCanceled();

    auto largeSeedsCompsBs = compsWithSeeds;
    for ( auto rId : compsWithSeeds )
    {
        if ( areas[rId].seedArea / areas[rId].totalArea < params.coverRatio )
            largeSeedsCompsBs.reset( rId );
    }
    res.resize( region.size() );
    BitSetParallelFor( region, [&] ( FaceId f )
    {
        res.set( f, largeSeedsCompsBs.test( compMap[f] ) );
    } );
    if ( !reportProgress( params.cb, 1.0f ) )