Function computeGeodesicPathApprox

source/MRMesh/MRSurfacePath.cpp:346–393

}

Expected<SurfacePath, PathError> computeGeodesicPathApprox( const Mesh & mesh,
    const MeshTriPoint & start, const MeshTriPoint & end, GeodesicPathApprox atype )
{
    MR_TIMER;
    if ( atype == GeodesicPathApprox::FastMarching )
        return computeFastMarchingPath( mesh, start, end );

    SurfacePath res;
    if ( !fromSameTriangle( mesh.topology, MeshTriPoint{ start }, MeshTriPoint{ end } ) )
    {
        VertId v1, v2;
        EdgePath edgePath = ( atype == GeodesicPathApprox::DijkstraBiDir ) ?
            buildShortestPathBiDir( mesh, start, end, &v1, &v2 ) :
            buildShortestPathAStar( mesh, start, end, &v1, &v2 );
        if ( !v1 || !v2 )
            return unexpected( PathError::StartEndNotConnected );

        // remove last segment from the path if end-point and the origin of last segment belong to one triangle
        while( !edgePath.empty()
            && fromSameTriangle( mesh.topology, MeshTriPoint{ end }, MeshTriPoint{ MeshEdgePoint{ edgePath.back(), 0 } } ) )
        {
            v2 = mesh.topology.org( edgePath.back() );
            edgePath.pop_back();
        }

        // remove first segment from the path if start-point and the destination of first segment belong to one triangle
        while( !edgePath.empty()
            && fromSameTriangle( mesh.topology, MeshTriPoint{ start }, MeshTriPoint{ MeshEdgePoint{ edgePath.front(), 1 } } ) )
        {
            v1 = mesh.topology.dest( edgePath.front() );
            edgePath.erase( edgePath.begin() );
        }

        if ( edgePath.empty() )
        {
            assert ( v1 == v2 );
            res = { MeshEdgePoint( mesh.topology.edgeWithOrg( v1 ), 0.0f ) };
        }
        else
        {
            res.reserve( edgePath.size() + 1 );
            for ( EdgeId e : edgePath )
                res.emplace_back( e, 0.0f );
            res.emplace_back( edgePath.back(), 1.0f );
        }
    }
    return res;
}

SurfacePath computeSteepestDescentPath( const MeshPart & mp, const VertScalars & field,
    const MeshTriPoint & start, const ComputeSteepestDescentPathSettings & settings )