meshRefinementMerge.C

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    Copyright (C) 2011-2014 OpenFOAM Foundation
    Copyright (C) 2016-2019 OpenCFD Ltd.
-------------------------------------------------------------------------------
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
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#include "meshRefinement.H"
#include "combineFaces.H"
#include "polyTopoChange.H"
#include "removePoints.H"
#include "faceSet.H"
#include "Time.H"
#include "motionSmoother.H"
#include "syncTools.H"
 
// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
// Merge faces that are in-line.
Foam::label Foam::meshRefinement::mergePatchFaces
(
    const scalar minCos,
    const scalar concaveCos,
    const label mergeSize,
    const labelList& patchIDs,
    const meshRefinement::FaceMergeType mergeType
)
{
    // Patch face merging engine
    combineFaces faceCombiner(mesh_, false);
 
    const polyBoundaryMesh& patches = mesh_.boundaryMesh();
 
    // Pick up all candidate cells on boundary
    labelHashSet boundaryCells(mesh_.nBoundaryFaces());
 
    for (const label patchi : patchIDs)
    {
        const polyPatch& patch = patches[patchi];
 
        if (!patch.coupled())
        {
            forAll(patch, i)
            {
                boundaryCells.insert(mesh_.faceOwner()[patch.start()+i]);
            }
        }
    }
 
    // Get all sets of faces that can be merged
    labelListList mergeSets
    (
        faceCombiner.getMergeSets
        (
            minCos,
            concaveCos,
            boundaryCells,
            (mergeType == FaceMergeType::IGNOREPATCH) // merge across patches?
        )
    );
 
    if (mergeSize != -1)
    {
        // Keep only those that are mergeSize faces
        label compactI = 0;
        forAll(mergeSets, setI)
        {
            if (mergeSets[setI].size() == mergeSize && compactI != setI)
            {
                mergeSets[compactI++] = mergeSets[setI];
            }
        }
        mergeSets.setSize(compactI);
    }
 
 
    label nFaceSets = returnReduce(mergeSets.size(), sumOp<label>());
 
    Info<< "Merging " << nFaceSets << " sets of faces." << nl << endl;
 
    if (nFaceSets > 0)
    {
        // Topology changes container
        polyTopoChange meshMod(mesh_);
 
        // Merge all faces of a set into the first face of the set. Remove
        // unused points.
        faceCombiner.setRefinement(mergeSets, meshMod);
 
        // Remove any unnecessary fields
        mesh_.clearOut();
        mesh_.moving(false);
 
        // Change the mesh (no inflation)
        autoPtr<mapPolyMesh> mapPtr = meshMod.changeMesh(mesh_, false, true);
        mapPolyMesh& map = *mapPtr;
 
        // Update fields
        mesh_.updateMesh(map);
 
        // Move mesh (since morphing does not do this)
        if (map.hasMotionPoints())
        {
            mesh_.movePoints(map.preMotionPoints());
        }
        else
        {
            // Delete mesh volumes. No other way to do this?
            mesh_.clearOut();
        }
 
        // Reset the instance for if in overwrite mode
        mesh_.setInstance(timeName());
 
        faceCombiner.updateMesh(map);
 
        // Get the kept faces that need to be recalculated.
        // Merging two boundary faces might shift the cell centre
        // (unless the faces are absolutely planar)
        labelHashSet retestFaces(2*mergeSets.size());
 
        forAll(mergeSets, setI)
        {
            label oldMasterI = mergeSets[setI][0];
            retestFaces.insert(map.reverseFaceMap()[oldMasterI]);
        }
        updateMesh(map, growFaceCellFace(retestFaces));
    }
 
    return nFaceSets;
}
 
 
//Foam::autoPtr<Foam::mapPolyMesh> Foam::meshRefinement::mergeEdges
//(
//    const scalar minCos
//)
//{
//    // Point removal analysis engine
//    removePoints pointRemover(mesh_);
//
//    // Count usage of points
//    boolList pointCanBeDeleted;
//    label nRemove = pointRemover.countPointUsage(minCos, pointCanBeDeleted);
//
//    Info<< "Removing " << nRemove
//        << " straight edge points." << endl;
//
//    autoPtr<mapPolyMesh> map;
//
//    if (nRemove > 0)
//    {
//        // Save my local faces that will change. These changed faces might
//        // cause a shift in the cell centre which needs to be retested.
//        // Have to do this before changing mesh since point will be removed.
//        labelHashSet retestOldFaces(nRemove / Pstream::nProcs());
//
//        {
//            const faceList& faces = mesh_.faces();
//
//            forAll(faces, faceI)
//            {
//                const face& f = faces[faceI];
//
//                forAll(f, fp)
//                {
//                    if (pointCanBeDeleted[f[fp]])
//                    {
//                        retestOldFaces.insert(faceI);
//                        break;
//                    }
//                }
//            }
//        }
//
//        // Topology changes container
//        polyTopoChange meshMod(mesh_);
//
//        pointRemover.setRefinement(pointCanBeDeleted, meshMod);
//
//        // Remove any unnecessary fields
//        mesh_.clearOut();
//        mesh_.moving(false);
//
//        // Change the mesh (no inflation)
//        map = meshMod.changeMesh(mesh_, false, true);
//
//        // Update fields
//        mesh_.updateMesh(map);
//
//        // Move mesh (since morphing does not do this)
//        if (map().hasMotionPoints())
//        {
//            mesh_.movePoints(map().preMotionPoints());
//        }
//        else
//        {
//            // Delete mesh volumes. No other way to do this?
//            mesh_.clearOut();
//        }
//
//        // Reset the instance for if in overwrite mode
//        mesh_.setInstance(timeName());
//
//        pointRemover.updateMesh(map);
//
//        // Get the kept faces that need to be recalculated.
//        labelHashSet retestFaces(6*retestOldFaces.size());
//
//        const cellList& cells = mesh_.cells();
//
//        for (const label oldFacei : retestOldFaces)
//        {
//            const label facei = map().reverseFaceMap()[oldFacei];
//
//            const cell& ownFaces = cells[mesh_.faceOwner()[facei]];
//
//            retestFaces.insert(ownFaces);
//
//            if (mesh_.isInternalFace(facei))
//            {
//                const cell& neiFaces = cells[mesh_.faceNeighbour()[facei]];
//
//                retestFaces.insert(neiFaces);
//            }
//        }
//        updateMesh(map, retestFaces.toc());
//    }
//
//    return map;
//}
 
 
Foam::label Foam::meshRefinement::mergePatchFacesUndo
(
    const scalar minCos,
    const scalar concaveCos,
    const labelList& patchIDs,
    const dictionary& motionDict,
    const labelList& preserveFaces,
    const meshRefinement::FaceMergeType mergeType
)
{
    // Patch face merging engine
    combineFaces faceCombiner(mesh_, true);
 
    // Pick up all candidate cells on boundary
    labelHashSet boundaryCells(mesh_.nBoundaryFaces());
 
    {
        const polyBoundaryMesh& patches = mesh_.boundaryMesh();
 
        for (const label patchi : patchIDs)
        {
            const polyPatch& patch = patches[patchi];
 
            if (!patch.coupled())
            {
                forAll(patch, i)
                {
                    boundaryCells.insert(mesh_.faceOwner()[patch.start()+i]);
                }
            }
        }
    }
 
    // Get all sets of faces that can be merged. Since only faces on the same
    // patch get merged there is no risk of e.g. patchID faces getting merged
    // with original patches (or even processor patches). There is a risk
    // though of original patch faces getting merged if they make a small
    // angle. Would be pretty weird starting mesh though.
    labelListList allFaceSets
    (
        faceCombiner.getMergeSets
        (
            minCos,
            concaveCos,
            boundaryCells,
            (mergeType == FaceMergeType::IGNOREPATCH) // merge across patches?
        )
    );
 
    // Filter out any set that contains any preserveFace
    label compactI = 0;
    forAll(allFaceSets, i)
    {
        const labelList& set = allFaceSets[i];
 
        bool keep = true;
        forAll(set, j)
        {
            if (preserveFaces[set[j]] != -1)
            {
                keep = false;
                break;
            }
        }
 
        if (keep)
        {
            if (compactI != i)
            {
                allFaceSets[compactI] = set;
            }
 
            compactI++;
        }
    }
    allFaceSets.setSize(compactI);
 
    label nFaceSets = returnReduce(allFaceSets.size(), sumOp<label>());
 
    Info<< "Merging " << nFaceSets << " sets of faces." << nl << endl;
 
    if (nFaceSets > 0)
    {
        if (debug&meshRefinement::MESH)
        {
            faceSet allSets(mesh_, "allFaceSets", allFaceSets.size());
            forAll(allFaceSets, setI)
            {
                allSets.insert(allFaceSets[setI]);
            }
            Pout<< "Writing all faces to be merged to set "
                << allSets.objectPath() << endl;
            allSets.instance() = timeName();
            allSets.write();
 
            const_cast<Time&>(mesh_.time())++;
        }
 
 
        // Topology changes container
        polyTopoChange meshMod(mesh_);
 
        // Merge all faces of a set into the first face of the set.
        faceCombiner.setRefinement(allFaceSets, meshMod);
 
        // Experimental: store data for all the points that have been deleted
        storeData
        (
            faceCombiner.savedPointLabels(),    // points to store
            labelList(0),                       // faces to store
            labelList(0)                        // cells to store
        );
 
        // Remove any unnecessary fields
        mesh_.clearOut();
        mesh_.moving(false);
 
        // Change the mesh (no inflation)
        autoPtr<mapPolyMesh> map = meshMod.changeMesh(mesh_, false, true);
 
        // Update fields
        mesh_.updateMesh(map());
 
        // Move mesh (since morphing does not do this)
        if (map().hasMotionPoints())
        {
            mesh_.movePoints(map().preMotionPoints());
        }
        else
        {
            // Delete mesh volumes.
            mesh_.clearOut();
        }
 
        // Reset the instance for if in overwrite mode
        mesh_.setInstance(timeName());
 
        faceCombiner.updateMesh(map());
 
        // Get the kept faces that need to be recalculated.
        // Merging two boundary faces might shift the cell centre
        // (unless the faces are absolutely planar)
        labelHashSet retestFaces(2*allFaceSets.size());
 
        forAll(allFaceSets, setI)
        {
            label oldMasterI = allFaceSets[setI][0];
            retestFaces.insert(map().reverseFaceMap()[oldMasterI]);
        }
        updateMesh(map(), growFaceCellFace(retestFaces));
 
        if (debug&meshRefinement::MESH)
        {
            // Check sync
            Pout<< "Checking sync after initial merging " << nFaceSets
                << " faces." << endl;
            checkData();
 
            Pout<< "Writing initial merged-faces mesh to time "
                << timeName() << nl << endl;
            write();
        }
 
        for (label iteration = 0; iteration < 100; iteration++)
        {
            Info<< nl
                << "Undo iteration " << iteration << nl
                << "----------------" << endl;
 
 
            // Check mesh for errors
            // ~~~~~~~~~~~~~~~~~~~~~
 
            faceSet errorFaces(mesh_, "errorFaces", mesh_.nBoundaryFaces());
            bool hasErrors = motionSmoother::checkMesh
            (
                false,  // report
                mesh_,
                motionDict,
                errorFaces,
                dryRun_
            );
 
            //if (checkEdgeConnectivity)
            //{
            //    Info<< "Checking edge-face connectivity (duplicate faces"
            //        << " or non-consecutive shared vertices)" << endl;
            //
            //    label nOldSize = errorFaces.size();
            //
            //    hasErrors =
            //        mesh_.checkFaceFaces
            //        (
            //            false,
            //            &errorFaces
            //        )
            //     || hasErrors;
            //
            //    Info<< "Detected additional "
            //        <<  returnReduce
            //            (
            //                errorFaces.size() - nOldSize,
            //                sumOp<label>()
            //            )
            //        << " faces with illegal face-face connectivity"
            //        << endl;
            //}
 
            if (!hasErrors)
            {
                break;
            }
 
 
            if (debug&meshRefinement::MESH)
            {
                errorFaces.instance() = timeName();
                Pout<< "Writing all faces in error to faceSet "
                    << errorFaces.objectPath() << nl << endl;
                errorFaces.write();
            }
 
 
            // Check any master cells for using any of the error faces
            // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
            DynamicList<label> mastersToRestore(allFaceSets.size());
 
            forAll(allFaceSets, setI)
            {
                label masterFaceI = faceCombiner.masterFace()[setI];
 
                if (masterFaceI != -1)
                {
                    label masterCellII = mesh_.faceOwner()[masterFaceI];
 
                    const cell& cFaces = mesh_.cells()[masterCellII];
 
                    forAll(cFaces, i)
                    {
                        if (errorFaces.found(cFaces[i]))
                        {
                            mastersToRestore.append(masterFaceI);
                            break;
                        }
                    }
                }
            }
            mastersToRestore.shrink();
 
            label nRestore = returnReduce
            (
                mastersToRestore.size(),
                sumOp<label>()
            );
 
            Info<< "Masters that need to be restored:"
                << nRestore << endl;
 
            if (debug&meshRefinement::MESH)
            {
                faceSet restoreSet(mesh_, "mastersToRestore", mastersToRestore);
                restoreSet.instance() = timeName();
                Pout<< "Writing all " << mastersToRestore.size()
                    << " masterfaces to be restored to set "
                    << restoreSet.objectPath() << endl;
                restoreSet.write();
            }
 
 
            if (nRestore == 0)
            {
                break;
            }
 
 
            // Undo
            // ~~~~
 
            if (debug)
            {
                const_cast<Time&>(mesh_.time())++;
            }
 
            // Topology changes container
            polyTopoChange meshMod(mesh_);
 
            // Merge all faces of a set into the first face of the set.
            // Experimental:mark all points/faces/cells that have been restored.
            Map<label> restoredPoints(0);
            Map<label> restoredFaces(0);
            Map<label> restoredCells(0);
 
            faceCombiner.setUnrefinement
            (
                mastersToRestore,
                meshMod,
                restoredPoints,
                restoredFaces,
                restoredCells
            );
 
            // Remove any unnecessary fields
            mesh_.clearOut();
            mesh_.moving(false);
 
            // Change the mesh (no inflation)
            autoPtr<mapPolyMesh> map = meshMod.changeMesh(mesh_, false, true);
 
            // Update fields
            mesh_.updateMesh(map());
 
            // Move mesh (since morphing does not do this)
            if (map().hasMotionPoints())
            {
                mesh_.movePoints(map().preMotionPoints());
            }
            else
            {
                // Delete mesh volumes.
                mesh_.clearOut();
            }
 
 
            // Reset the instance for if in overwrite mode
            mesh_.setInstance(timeName());
 
            faceCombiner.updateMesh(map());
 
            // Renumber restore maps
            inplaceMapKey(map().reversePointMap(), restoredPoints);
            inplaceMapKey(map().reverseFaceMap(), restoredFaces);
            inplaceMapKey(map().reverseCellMap(), restoredCells);
 
 
            // Get the kept faces that need to be recalculated.
            // Merging two boundary faces might shift the cell centre
            // (unless the faces are absolutely planar)
            labelHashSet retestFaces(2*restoredFaces.size());
 
            forAllConstIters(restoredFaces, iter)
            {
                retestFaces.insert(iter.key());
            }
 
            // Experimental:restore all points/face/cells in maps
            updateMesh
            (
                map(),
                growFaceCellFace(retestFaces),
                restoredPoints,
                restoredFaces,
                restoredCells
            );
 
            if (debug&meshRefinement::MESH)
            {
                // Check sync
                Pout<< "Checking sync after restoring " << retestFaces.size()
                    << " faces." << endl;
                checkData();
 
                Pout<< "Writing merged-faces mesh to time "
                    << timeName() << nl << endl;
                write();
            }
 
            Info<< endl;
        }
    }
    else
    {
        Info<< "No faces merged ..." << endl;
    }
 
    return nFaceSets;
}
 
 
// Remove points. pointCanBeDeleted is parallel synchronised.
Foam::autoPtr<Foam::mapPolyMesh> Foam::meshRefinement::doRemovePoints
(
    removePoints& pointRemover,
    const boolList& pointCanBeDeleted
)
{
    // Topology changes container
    polyTopoChange meshMod(mesh_);
 
    pointRemover.setRefinement(pointCanBeDeleted, meshMod);
 
    // Remove any unnecessary fields
    mesh_.clearOut();
    mesh_.moving(false);
 
    // Change the mesh (no inflation)
    autoPtr<mapPolyMesh> mapPtr = meshMod.changeMesh(mesh_, false, true);
    mapPolyMesh& map = *mapPtr;
 
    // Update fields
    mesh_.updateMesh(map);
 
    // Move mesh (since morphing does not do this)
    if (map.hasMotionPoints())
    {
        mesh_.movePoints(map.preMotionPoints());
    }
    else
    {
        // Delete mesh volumes.
        mesh_.clearOut();
    }
 
    // Reset the instance for if in overwrite mode
    mesh_.setInstance(timeName());
 
    pointRemover.updateMesh(map);
 
 
    // Retest all affected faces and all the cells using them
    labelHashSet retestFaces(pointRemover.savedFaceLabels().size());
    for (const label facei : pointRemover.savedFaceLabels())
    {
        if (facei >= 0)
        {
            retestFaces.insert(facei);
        }
    }
    updateMesh(map, growFaceCellFace(retestFaces));
 
    if (debug)
    {
        // Check sync
        Pout<< "Checking sync after removing points." << endl;
        checkData();
    }
 
    return mapPtr;
}
 
 
// Restore faces (which contain removed points)
Foam::autoPtr<Foam::mapPolyMesh> Foam::meshRefinement::doRestorePoints
(
    removePoints& pointRemover,
    const labelList& facesToRestore
)
{
    // Topology changes container
    polyTopoChange meshMod(mesh_);
 
    // Determine sets of points and faces to restore
    labelList localFaces, localPoints;
    pointRemover.getUnrefimentSet
    (
        facesToRestore,
        localFaces,
        localPoints
    );
 
    // Undo the changes on the faces that are in error.
    pointRemover.setUnrefinement
    (
        localFaces,
        localPoints,
        meshMod
    );
 
    // Remove any unnecessary fields
    mesh_.clearOut();
    mesh_.moving(false);
 
    // Change the mesh (no inflation)
    autoPtr<mapPolyMesh> mapPtr = meshMod.changeMesh(mesh_, false, true);
    mapPolyMesh& map = *mapPtr;
 
    // Update fields
    mesh_.updateMesh(map);
 
    // Move mesh (since morphing does not do this)
    if (map.hasMotionPoints())
    {
        mesh_.movePoints(map.preMotionPoints());
    }
    else
    {
        // Delete mesh volumes.
        mesh_.clearOut();
    }
 
    // Reset the instance for if in overwrite mode
    mesh_.setInstance(timeName());
 
    pointRemover.updateMesh(map);
 
    labelHashSet retestFaces(2*facesToRestore.size());
    forAll(facesToRestore, i)
    {
        label faceI = map.reverseFaceMap()[facesToRestore[i]];
        if (faceI >= 0)
        {
            retestFaces.insert(faceI);
        }
    }
    updateMesh(map, growFaceCellFace(retestFaces));
 
    if (debug)
    {
        // Check sync
        Pout<< "Checking sync after restoring points on "
            << facesToRestore.size() << " faces." << endl;
        checkData();
    }
 
    return mapPtr;
}
 
 
// Collect all faces that are both in candidateFaces and in the set.
// If coupled face also collects the coupled face.
Foam::labelList Foam::meshRefinement::collectFaces
(
    const labelList& candidateFaces,
    const labelHashSet& set
) const
{
    // Has face been selected?
    boolList selected(mesh_.nFaces(), false);
 
    for (const label facei : candidateFaces)
    {
        if (set.found(facei))
        {
            selected[facei] = true;
        }
    }
    syncTools::syncFaceList
    (
        mesh_,
        selected,
        orEqOp<bool>()      // combine operator
    );
 
    labelList selectedFaces(findIndices(selected, true));
 
    return selectedFaces;
}
 
 
namespace Foam
{
    // Pick up faces of cells of faces in set.
    // file-scope
    static inline void markGrowFaceCellFace
    (
        const polyMesh& pMesh,
        const label faceI,
        boolList& selected
    )
    {
        const label own = pMesh.faceOwner()[faceI];
 
        const cell& ownFaces = pMesh.cells()[own];
        for (const label facei : ownFaces)
        {
            selected[facei] = true;
        }
 
        if (pMesh.isInternalFace(faceI))
        {
            const label nbr = pMesh.faceNeighbour()[faceI];
 
            const cell& nbrFaces = pMesh.cells()[nbr];
            forAll(nbrFaces, nbrFaceI)
            {
                selected[nbrFaces[nbrFaceI]] = true;
            }
        }
    }
}
 
 
// Pick up faces of cells of faces in set.
Foam::labelList Foam::meshRefinement::growFaceCellFace
(
    const labelUList& set
) const
{
    boolList selected(mesh_.nFaces(), false);
 
    for (const label facei : set)
    {
        markGrowFaceCellFace(mesh_, facei, selected);
    }
 
    syncTools::syncFaceList
    (
        mesh_,
        selected,
        orEqOp<bool>()      // combine operator
    );
    return findIndices(selected, true);
}
 
 
// Pick up faces of cells of faces in set.
Foam::labelList Foam::meshRefinement::growFaceCellFace
(
    const labelHashSet& set
) const
{
    boolList selected(mesh_.nFaces(), false);
 
    for (const label facei : set)
    {
        markGrowFaceCellFace(mesh_, facei, selected);
    }
 
    syncTools::syncFaceList
    (
        mesh_,
        selected,
        orEqOp<bool>()      // combine operator
    );
    return findIndices(selected, true);
}
 
 
// Remove points not used by any face or points used by only two faces where
// the edges are in line
Foam::label Foam::meshRefinement::mergeEdgesUndo
(
    const scalar minCos,
    const dictionary& motionDict
)
{
    Info<< nl
        << "Merging all points on surface that" << nl
        << "- are used by only two boundary faces and" << nl
        << "- make an angle with a cosine of more than " << minCos
        << "." << nl << endl;
 
    // Point removal analysis engine with undo
    removePoints pointRemover(mesh_, true);
 
    // Count usage of points
    boolList pointCanBeDeleted;
    label nRemove = pointRemover.countPointUsage(minCos, pointCanBeDeleted);
 
    if (nRemove > 0)
    {
        Info<< "Removing " << nRemove
            << " straight edge points ..." << nl << endl;
 
        // Remove points
        // ~~~~~~~~~~~~~
 
        doRemovePoints(pointRemover, pointCanBeDeleted);
 
 
        for (label iteration = 0; iteration < 100; iteration++)
        {
            Info<< nl
                << "Undo iteration " << iteration << nl
                << "----------------" << endl;
 
 
            // Check mesh for errors
            // ~~~~~~~~~~~~~~~~~~~~~
 
            faceSet errorFaces(mesh_, "errorFaces", mesh_.nBoundaryFaces());
            bool hasErrors = motionSmoother::checkMesh
            (
                false,  // report
                mesh_,
                motionDict,
                errorFaces,
                dryRun_
            );
            //if (checkEdgeConnectivity)
            //{
            //    Info<< "Checking edge-face connectivity (duplicate faces"
            //        << " or non-consecutive shared vertices)" << endl;
            //
            //    label nOldSize = errorFaces.size();
            //
            //    hasErrors =
            //        mesh_.checkFaceFaces
            //        (
            //            false,
            //            &errorFaces
            //        )
            //     || hasErrors;
            //
            //    Info<< "Detected additional "
            //        << returnReduce(errorFaces.size()-nOldSize,sumOp<label>())
            //        << " faces with illegal face-face connectivity"
            //        << endl;
            //}
 
            if (!hasErrors)
            {
                break;
            }
 
            if (debug&meshRefinement::MESH)
            {
                errorFaces.instance() = timeName();
                Pout<< "**Writing all faces in error to faceSet "
                    << errorFaces.objectPath() << nl << endl;
                errorFaces.write();
            }
 
            labelList masterErrorFaces
            (
                collectFaces
                (
                    pointRemover.savedFaceLabels(),
                    errorFaces
                )
            );
 
            label n = returnReduce(masterErrorFaces.size(), sumOp<label>());
 
            Info<< "Detected " << n
                << " error faces on boundaries that have been merged."
                << " These will be restored to their original faces." << nl
                << endl;
 
            if (n == 0)
            {
                if (hasErrors)
                {
                    Info<< "Detected "
                        << returnReduce(errorFaces.size(), sumOp<label>())
                        << " error faces in mesh."
                        << " Restoring neighbours of faces in error." << nl
                        << endl;
 
                    labelList expandedErrorFaces
                    (
                        growFaceCellFace
                        (
                            errorFaces
                        )
                    );
 
                    doRestorePoints(pointRemover, expandedErrorFaces);
                }
 
                break;
            }
 
            doRestorePoints(pointRemover, masterErrorFaces);
        }
 
        if (debug&meshRefinement::MESH)
        {
            const_cast<Time&>(mesh_.time())++;
            Pout<< "Writing merged-edges mesh to time "
                << timeName() << nl << endl;
            write();
        }
    }
    else
    {
        Info<< "No straight edges simplified and no points removed ..." << endl;
    }
 
    return nRemove;
}
 
 
// ************************************************************************* //