/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | Copyright (C) 2011-2018 OpenFOAM Foundation
     \\/     M anipulation  |
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.

    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.

\*---------------------------------------------------------------------------*/

#include "meshSearch.H"
#include "polyMesh.H"
#include "indexedOctree.H"
#include "DynamicList.H"
#include "demandDrivenData.H"
#include "treeDataCell.H"
#include "treeDataFace.H"

// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //

namespace Foam
{
    defineTypeNameAndDebug(meshSearch, 0);

    scalar meshSearch::tol_ = 1e-3;


    class findUniqueIntersectOp
    {
    public:
        const indexedOctree<treeDataFace>& tree_;
        DynamicList<label>& checkedIndices_;

    public:

        findUniqueIntersectOp
        (
            const indexedOctree<treeDataFace>& tree,
            DynamicList<label>& checkedIndices
        )
        :
            tree_(tree),
            checkedIndices_(checkedIndices)
        {}


        //- Calculate intersection of triangle with ray. Sets result
        //  accordingly
        bool operator()
        (
            const label index,
            const point& start,
            const point& end,
            point& intersectionPoint
        ) const
        {
            const treeDataFace& shape = tree_.shapes();
            const primitiveMesh& mesh = shape.mesh();

            if (findIndex(checkedIndices_, index) != -1)
            {
                return false;
            }
            checkedIndices_.append(index);

            const label facei = shape.faceLabels()[index];

            const vector dir(end - start);

            pointHit inter = mesh.faces()[facei].intersection
            (
                start,
                dir,
                mesh.faceCentres()[facei],
                mesh.points(),
                intersection::HALF_RAY
            );

            if (inter.hit() && inter.distance() <= 1)
            {
                // Note: no extra test on whether intersection is in front of us
                // since using half_ray
                intersectionPoint = inter.hitPoint();
                return true;
            }
            else
            {
                return false;
            }
        }
    };
}


// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //

bool Foam::meshSearch::findNearer
(
    const point& sample,
    const pointField& points,
    label& nearestI,
    scalar& nearestDistSqr
)
{
    bool nearer = false;

    forAll(points, pointi)
    {
        scalar distSqr = magSqr(points[pointi] - sample);

        if (distSqr < nearestDistSqr)
        {
            nearestDistSqr = distSqr;
            nearestI = pointi;
            nearer = true;
        }
    }

    return nearer;
}


bool Foam::meshSearch::findNearer
(
    const point& sample,
    const pointField& points,
    const labelList& indices,
    label& nearestI,
    scalar& nearestDistSqr
)
{
    bool nearer = false;

    forAll(indices, i)
    {
        label pointi = indices[i];

        scalar distSqr = magSqr(points[pointi] - sample);

        if (distSqr < nearestDistSqr)
        {
            nearestDistSqr = distSqr;
            nearestI = pointi;
            nearer = true;
        }
    }

    return nearer;
}


// tree based searching
Foam::label Foam::meshSearch::findNearestCellTree(const point& location) const
{
    const indexedOctree<treeDataCell>& tree = cellTree();

    pointIndexHit info = tree.findNearest
    (
        location,
        magSqr(tree.bb().max()-tree.bb().min())
    );

    if (!info.hit())
    {
        info = tree.findNearest(location, Foam::sqr(great));
    }
    return info.index();
}


Foam::label Foam::meshSearch::findNearestCellLinear(const point& location) const
{
    const vectorField& centres = mesh_.cellCentres();

    label nearestIndex = 0;
    scalar minProximity = magSqr(centres[nearestIndex] - location);

    findNearer
    (
        location,
        centres,
        nearestIndex,
        minProximity
    );

    return nearestIndex;
}


Foam::label Foam::meshSearch::findNearestCellWalk
(
    const point& location,
    const label seedCelli
) const
{
    if (seedCelli < 0)
    {
        FatalErrorInFunction
            << "illegal seedCell:" << seedCelli << exit(FatalError);
    }

    // Walk in direction of face that decreases distance

    label curCelli = seedCelli;
    scalar distanceSqr = magSqr(mesh_.cellCentres()[curCelli] - location);

    bool closer;

    do
    {
        // Try neighbours of curCelli
        closer = findNearer
        (
            location,
            mesh_.cellCentres(),
            mesh_.cellCells()[curCelli],
            curCelli,
            distanceSqr
        );
    } while (closer);

    return curCelli;
}


Foam::label Foam::meshSearch::findNearestFaceTree(const point& location) const
{
    // Search nearest cell centre.
    const indexedOctree<treeDataCell>& tree = cellTree();

    // Search with decent span
    pointIndexHit info = tree.findNearest
    (
        location,
        magSqr(tree.bb().max()-tree.bb().min())
    );

    if (!info.hit())
    {
        // Search with desperate span
        info = tree.findNearest(location, Foam::sqr(great));
    }


    // Now check any of the faces of the nearest cell
    const vectorField& centres = mesh_.faceCentres();
    const cell& ownFaces = mesh_.cells()[info.index()];

    label nearestFacei = ownFaces[0];
    scalar minProximity = magSqr(centres[nearestFacei] - location);

    findNearer
    (
        location,
        centres,
        ownFaces,
        nearestFacei,
        minProximity
    );

    return nearestFacei;
}


Foam::label Foam::meshSearch::findNearestFaceLinear(const point& location) const
{
    const vectorField& centres = mesh_.faceCentres();

    label nearestFacei = 0;
    scalar minProximity = magSqr(centres[nearestFacei] - location);

    findNearer
    (
        location,
        centres,
        nearestFacei,
        minProximity
    );

    return nearestFacei;
}


Foam::label Foam::meshSearch::findNearestFaceWalk
(
    const point& location,
    const label seedFacei
) const
{
    if (seedFacei < 0)
    {
        FatalErrorInFunction
            << "illegal seedFace:" << seedFacei << exit(FatalError);
    }

    const vectorField& centres = mesh_.faceCentres();


    // Walk in direction of face that decreases distance

    label curFacei = seedFacei;
    scalar distanceSqr = magSqr(centres[curFacei] - location);

    while (true)
    {
        label betterFacei = curFacei;

        findNearer
        (
            location,
            centres,
            mesh_.cells()[mesh_.faceOwner()[curFacei]],
            betterFacei,
            distanceSqr
        );

        if (mesh_.isInternalFace(curFacei))
        {
            findNearer
            (
                location,
                centres,
                mesh_.cells()[mesh_.faceNeighbour()[curFacei]],
                betterFacei,
                distanceSqr
            );
        }

        if (betterFacei == curFacei)
        {
            break;
        }

        curFacei = betterFacei;
    }

    return curFacei;
}


Foam::label Foam::meshSearch::findCellLinear(const point& location) const
{
    bool cellFound = false;
    label n = 0;

    label celli = -1;

    while ((!cellFound) && (n < mesh_.nCells()))
    {
        if (mesh_.pointInCell(location, n, cellDecompMode_))
        {
            cellFound = true;
            celli = n;
        }
        else
        {
            n++;
        }
    }
    if (cellFound)
    {
        return celli;
    }
    else
    {
        return -1;
    }
}


Foam::label Foam::meshSearch::findCellWalk
(
    const point& location,
    const label seedCelli
) const
{
    if (seedCelli < 0)
    {
        FatalErrorInFunction
            << "illegal seedCell:" << seedCelli << exit(FatalError);
    }

    if (mesh_.pointInCell(location, seedCelli, cellDecompMode_))
    {
        return seedCelli;
    }

    // Walk in direction of face that decreases distance
    label curCelli = seedCelli;
    scalar nearestDistSqr = magSqr(mesh_.cellCentres()[curCelli] - location);

    while(true)
    {
        // Try neighbours of curCelli

        const cell& cFaces = mesh_.cells()[curCelli];

        label nearestCelli = -1;

        forAll(cFaces, i)
        {
            label facei = cFaces[i];

            if (mesh_.isInternalFace(facei))
            {
                label celli = mesh_.faceOwner()[facei];
                if (celli == curCelli)
                {
                    celli = mesh_.faceNeighbour()[facei];
                }

                // Check if this is the correct cell
                if (mesh_.pointInCell(location, celli, cellDecompMode_))
                {
                    return celli;
                }

                // Also calculate the nearest cell
                scalar distSqr = magSqr(mesh_.cellCentres()[celli] - location);

                if (distSqr < nearestDistSqr)
                {
                    nearestDistSqr = distSqr;
                    nearestCelli = celli;
                }
            }
        }

        if (nearestCelli == -1)
        {
            return -1;
        }

        // Continue with the nearest cell
        curCelli = nearestCelli;
    }

    return -1;
}


Foam::label Foam::meshSearch::findNearestBoundaryFaceWalk
(
    const point& location,
    const label seedFacei
) const
{
    if (seedFacei < 0)
    {
        FatalErrorInFunction
            << "illegal seedFace:" << seedFacei << exit(FatalError);
    }

    // Start off from seedFacei

    label curFacei = seedFacei;

    const face& f =  mesh_.faces()[curFacei];

    scalar minDist = f.nearestPoint
    (
        location,
        mesh_.points()
    ).distance();

    bool closer;

    do
    {
        closer = false;

        // Search through all neighbouring boundary faces by going
        // across edges

        label lastFacei = curFacei;

        const labelList& myEdges = mesh_.faceEdges()[curFacei];

        forAll(myEdges, myEdgeI)
        {
            const labelList& neighbours = mesh_.edgeFaces()[myEdges[myEdgeI]];

            // Check any face which uses edge, is boundary face and
            // is not curFacei itself.

            forAll(neighbours, nI)
            {
                label facei = neighbours[nI];

                if
                (
                    (facei >= mesh_.nInternalFaces())
                 && (facei != lastFacei)
                )
                {
                    const face& f =  mesh_.faces()[facei];

                    pointHit curHit = f.nearestPoint
                    (
                        location,
                        mesh_.points()
                    );

                    // If the face is closer, reset current face and distance
                    if (curHit.distance() < minDist)
                    {
                        minDist = curHit.distance();
                        curFacei = facei;
                        closer = true;  // a closer neighbour has been found
                    }
                }
            }
        }
    } while (closer);

    return curFacei;
}


// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //

Foam::meshSearch::meshSearch
(
    const polyMesh& mesh,
    const polyMesh::cellDecomposition cellDecompMode
)
:
    mesh_(mesh),
    cellDecompMode_(cellDecompMode)
{
    if
    (
        cellDecompMode_ == polyMesh::FACE_DIAG_TRIS
     || cellDecompMode_ == polyMesh::CELL_TETS)
    {
        // Force construction of face diagonals
        (void)mesh.tetBasePtIs();
    }
}


Foam::meshSearch::meshSearch
(
    const polyMesh& mesh,
    const treeBoundBox& bb,
    const polyMesh::cellDecomposition cellDecompMode
)
:
    mesh_(mesh),
    cellDecompMode_(cellDecompMode)
{
    overallBbPtr_.reset(new treeBoundBox(bb));

    if
    (
        cellDecompMode_ == polyMesh::FACE_DIAG_TRIS
     || cellDecompMode_ == polyMesh::CELL_TETS
    )
    {
        // Force construction of face diagonals
        (void)mesh.tetBasePtIs();
    }
}


// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //

Foam::meshSearch::~meshSearch()
{
    clearOut();
}


// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

const Foam::indexedOctree<Foam::treeDataFace>&
Foam::meshSearch::boundaryTree() const
{
    if (!boundaryTreePtr_.valid())
    {
        //
        // Construct tree
        //

        if (!overallBbPtr_.valid())
        {
            overallBbPtr_.reset
            (
                new treeBoundBox(mesh_.points())
            );

            treeBoundBox& overallBb = overallBbPtr_();

            // Extend slightly and make 3D
            overallBb = overallBb.extend(1e-4);
        }

        // all boundary faces (not just walls)
        labelList bndFaces(mesh_.nFaces()-mesh_.nInternalFaces());
        forAll(bndFaces, i)
        {
            bndFaces[i] = mesh_.nInternalFaces() + i;
        }

        boundaryTreePtr_.reset
        (
            new indexedOctree<treeDataFace>
            (
                treeDataFace    // all information needed to search faces
                (
                    false,                      // do not cache bb
                    mesh_,
                    bndFaces                    // boundary faces only
                ),
                overallBbPtr_(),                // overall search domain
                8,                              // maxLevel
                10,                             // leafsize
                3.0                             // duplicity
            )
        );
    }

    return boundaryTreePtr_();
}


const Foam::indexedOctree<Foam::treeDataCell>&
Foam::meshSearch::cellTree() const
{
    if (!cellTreePtr_.valid())
    {
        //
        // Construct tree
        //

        if (!overallBbPtr_.valid())
        {
            overallBbPtr_.reset
            (
                new treeBoundBox(mesh_.points())
            );

            treeBoundBox& overallBb = overallBbPtr_();

            // Extend slightly and make 3D
            overallBb = overallBb.extend(1e-4);
        }

        cellTreePtr_.reset
        (
            new indexedOctree<treeDataCell>
            (
                treeDataCell
                (
                    false,          // not cache bb
                    mesh_,
                    cellDecompMode_ // cell decomposition mode for inside tests
                ),
                overallBbPtr_(),
                8,              // maxLevel
                10,             // leafsize
                6.0             // duplicity
            )
        );
    }

    return cellTreePtr_();
}


Foam::label Foam::meshSearch::findNearestCell
(
    const point& location,
    const label seedCelli,
    const bool useTreeSearch
) const
{
    if (seedCelli == -1)
    {
        if (useTreeSearch)
        {
            return findNearestCellTree(location);
        }
        else
        {
            return findNearestCellLinear(location);
        }
    }
    else
    {
        return findNearestCellWalk(location, seedCelli);
    }
}


Foam::label Foam::meshSearch::findNearestFace
(
    const point& location,
    const label seedFacei,
    const bool useTreeSearch
) const
{
    if (seedFacei == -1)
    {
        if (useTreeSearch)
        {
            return findNearestFaceTree(location);
        }
        else
        {
            return findNearestFaceLinear(location);
        }
    }
    else
    {
        return findNearestFaceWalk(location, seedFacei);
    }
}


Foam::label Foam::meshSearch::findCell
(
    const point& location,
    const label seedCelli,
    const bool useTreeSearch
) const
{
    // Find the nearest cell centre to this location
    if (seedCelli == -1)
    {
        if (useTreeSearch)
        {
            return cellTree().findInside(location);
        }
        else
        {
            return findCellLinear(location);
        }
    }
    else
    {
        return findCellWalk(location, seedCelli);
    }
}


Foam::label Foam::meshSearch::findNearestBoundaryFace
(
    const point& location,
    const label seedFacei,
    const bool useTreeSearch
) const
{
    if (seedFacei == -1)
    {
        if (useTreeSearch)
        {
            const indexedOctree<treeDataFace>& tree = boundaryTree();

            pointIndexHit info = boundaryTree().findNearest
            (
                location,
                magSqr(tree.bb().max()-tree.bb().min())
            );

            if (!info.hit())
            {
                info = boundaryTree().findNearest
                (
                    location,
                    Foam::sqr(great)
                );
            }

            return tree.shapes().faceLabels()[info.index()];
        }
        else
        {
            scalar minDist = great;

            label minFacei = -1;

            for
            (
                label facei = mesh_.nInternalFaces();
                facei < mesh_.nFaces();
                facei++
            )
            {
                const face& f =  mesh_.faces()[facei];

                pointHit curHit =
                    f.nearestPoint
                    (
                        location,
                        mesh_.points()
                    );

                if (curHit.distance() < minDist)
                {
                    minDist = curHit.distance();
                    minFacei = facei;
                }
            }
            return minFacei;
        }
    }
    else
    {
        return findNearestBoundaryFaceWalk(location, seedFacei);
    }
}


Foam::pointIndexHit Foam::meshSearch::intersection
(
    const point& pStart,
    const point& pEnd
) const
{
    pointIndexHit curHit = boundaryTree().findLine(pStart, pEnd);

    if (curHit.hit())
    {
        // Change index into octreeData into face label
        curHit.setIndex(boundaryTree().shapes().faceLabels()[curHit.index()]);
    }
    return curHit;
}


Foam::List<Foam::pointIndexHit> Foam::meshSearch::intersections
(
    const point& pStart,
    const point& pEnd
) const
{
    const indexedOctree<Foam::treeDataFace>& tree = boundaryTree();

    DynamicList<label> checkedFaces;
    findUniqueIntersectOp iop(tree, checkedFaces);

    DynamicList<pointIndexHit> hits;

    vector edgeVec = pEnd - pStart;
    edgeVec /= mag(edgeVec);

    point pt = pStart;

    pointIndexHit bHit;
    do
    {
        bHit = tree.findLine(pt, pEnd, iop);

        if (bHit.hit())
        {
            // Change index into octreeData into face label
            bHit.setIndex(tree.shapes().faceLabels()[bHit.index()]);

            hits.append(bHit);

            const vector& area = mesh_.faceAreas()[bHit.index()];

            scalar typDim = Foam::sqrt(mag(area));

            if ((mag(bHit.hitPoint() - pEnd)/typDim) < small)
            {
                break;
            }

            pt = bHit.hitPoint();
        }

    } while (bHit.hit());


    hits.shrink();

    return hits;
}


bool Foam::meshSearch::isInside(const point& p) const
{
    return (boundaryTree().getVolumeType(p) == volumeType::INSIDE);
}


void Foam::meshSearch::clearOut()
{
    boundaryTreePtr_.clear();
    cellTreePtr_.clear();
    overallBbPtr_.clear();
}


void Foam::meshSearch::correct()
{
    clearOut();
}


// ************************************************************************* //

/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | Copyright (C) 2011-2016 OpenFOAM Foundation
     \\/     M anipulation  |
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.

    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.

Class
    Foam::meshSearch

Description
    Various (local, not parallel) searches on polyMesh;
    uses (demand driven) octree to search.

SourceFiles
    meshSearch.C

\*---------------------------------------------------------------------------*/

#ifndef meshSearch_H
#define meshSearch_H

#include "pointIndexHit.H"
#include "pointField.H"
#include "polyMesh.H"

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

namespace Foam
{

// Forward declaration of classes
class treeDataCell;
class treeDataFace;
template<class Type> class indexedOctree;
class treeBoundBox;

/*---------------------------------------------------------------------------*\
                           Class meshSearch Declaration
\*---------------------------------------------------------------------------*/

class meshSearch
{
    // Private data

        //- Reference to mesh
        const polyMesh& mesh_;

        //- Whether to use cell decomposition for all geometric tests
        const polyMesh::cellDecomposition cellDecompMode_;

        //- Data bounding box
        mutable autoPtr<treeBoundBox> overallBbPtr_;

        //- Demand driven octrees
        mutable autoPtr<indexedOctree<treeDataFace>> boundaryTreePtr_;
        mutable autoPtr<indexedOctree<treeDataCell>> cellTreePtr_;


    // Private Member Functions

        //- Updates nearestI, nearestDistSqr from any closer ones.
        static bool findNearer
        (
            const point& sample,
            const pointField& points,
            label& nearestI,
            scalar& nearestDistSqr
        );

        //- Updates nearestI, nearestDistSqr from any selected closer ones.
        static bool findNearer
        (
            const point& sample,
            const pointField& points,
            const labelList& indices,
            label& nearestI,
            scalar& nearestDistSqr
        );


        // Cells

            //- Nearest cell centre using octree
            label findNearestCellTree(const point&) const;

            //- Nearest cell centre going through all cells
            label findNearestCellLinear(const point&) const;

            //- Walk from seed. Does not 'go around' boundary, just returns
            //  last cell before boundary.
            label findNearestCellWalk(const point&, const label) const;

            //- Cell containing location. Linear search.
            label findCellLinear(const point&) const;

            //- Walk from seed. Does not 'go around' boundary, just returns
            //  last cell before boundary.
            label findCellWalk(const point&, const label) const;


        // Faces

            label findNearestFaceTree(const point&) const;

            label findNearestFaceLinear(const point&) const;

            label findNearestFaceWalk(const point&, const label) const;



        // Boundary faces

            //- Walk from seed to find nearest boundary face. Gets stuck in
            //  local minimum.
            label findNearestBoundaryFaceWalk
            (
                const point& location,
                const label seedFacei
            ) const;


        //- Disallow default bitwise copy construct
        meshSearch(const meshSearch&);

        //- Disallow default bitwise assignment
        void operator=(const meshSearch&);


public:

    // Declare name of the class and its debug switch
    ClassName("meshSearch");


    // Static data members

        //- Tolerance on linear dimensions
        static scalar tol_;


    // Constructors

        //- Construct from components. Constructs bb slightly bigger than
        //  mesh points bb.
        meshSearch
        (
            const polyMesh& mesh,
            const polyMesh::cellDecomposition = polyMesh::CELL_TETS
        );

        //- Construct with a custom bounding box. Any mesh element outside
        //  bb will not be found. Up to user to make sure bb
        //  extends slightly beyond wanted elements.
        meshSearch
        (
            const polyMesh& mesh,
            const treeBoundBox& bb,
            const polyMesh::cellDecomposition = polyMesh::CELL_TETS
        );

    //- Destructor
    ~meshSearch();


    // Member Functions

        // Access

            const polyMesh& mesh() const
            {
                return mesh_;
            }

            polyMesh::cellDecomposition decompMode() const
            {
                return cellDecompMode_;
            }

            //- Get (demand driven) reference to octree holding all
            //  boundary faces
            const indexedOctree<treeDataFace>& boundaryTree() const;

            //- Get (demand driven) reference to octree holding all cells
            const indexedOctree<treeDataCell>& cellTree() const;


        // Queries

            //- Find nearest cell in terms of cell centre.
            //  Options:
            //  - use octree
            //  - use linear search
            //  - if seed is provided walk. (uses findNearestCellWalk;
            //    does not handle holes in domain)
            label findNearestCell
            (
                const point& location,
                const label seedCelli = -1,
                const bool useTreeSearch = true
            ) const;

            label findNearestFace
            (
                const point& location,
                const label seedFacei = -1,
                const bool useTreeSearch = true
            ) const;

            //- Find cell containing location.
            //  If seed provided walks and falls back to linear/tree search.
            //  (so handles holes correctly)s
            //  Returns -1 if not in domain.
            label findCell
            (
                const point& location,
                const label seedCelli = -1,
                const bool useTreeSearch = true
            ) const;

            //- Find nearest boundary face
            //  If seed provided walks but then does not pass local minima
            //  in distance. Also does not jump from one connected region to
            //  the next.
            label findNearestBoundaryFace
            (
                const point& location,
                const label seedFacei = -1,
                const bool useTreeSearch = true
            ) const;

            //- Find first intersection of boundary in segment [pStart, pEnd]
            //  (so inclusive of endpoints). Always octree for now
            pointIndexHit intersection(const point& pStart, const point& pEnd)
            const;

            //- Find all intersections of boundary within segment pStart .. pEnd
            //  Always octree for now
            List<pointIndexHit> intersections
            (
                const point& pStart,
                const point& pEnd
            ) const;

            //- Determine inside/outside status
            bool isInside(const point&) const;


        //- Delete all storage
        void clearOut();

        //- Correct for mesh geom/topo changes
        void correct();
};


// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

} // End namespace Foam

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

#endif

// ************************************************************************* //