BoundaryPeriodicity.hpp

/*
  Copyright 2011 SINTEF ICT, Applied Mathematics.

  This file is part of the Open Porous Media project (OPM).

  OPM 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.

  OPM 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 OPM.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef OPM_BOUNDARYPERIODICITY_HEADER_INCLUDED
#define OPM_BOUNDARYPERIODICITY_HEADER_INCLUDED

#include <dune/common/fvector.hh>

#include <opm/common/ErrorMacros.hpp>

#include <algorithm>
#include <array>
#include <iostream>
#include <numbers>
#include <vector>

namespace Opm
{

    struct BoundaryFaceInfo
    {
        int face_index;
        int bid;
        int canon_pos;
        int partner_face_index;
        int partner_bid;
        double area;
        Dune::FieldVector<double,3> centroid;

        bool operator<(const BoundaryFaceInfo& other) const
        {
            return cmpval() < other.cmpval();
        }

    private:
        double cmpval() const
        {
            return centroid[(canon_pos/2 + 1)%3]
                +  std::numbers::pi*centroid[(canon_pos/2 + 2)%3];
        }
    };


    bool match(std::vector<BoundaryFaceInfo>& bfaces, int face, int lower, int upper);

    template <class GridView>
    void findPeriodicPartners(std::vector<BoundaryFaceInfo>& bfinfo,
                              std::array<double, 6>& side_areas,
                              const GridView& g,
                              const std::array<bool, 2*GridView::dimension>& is_periodic,
                              double spatial_tolerance = 1e-6)
    {
        // Pick out all boundary faces, simultaneously find the
        // bounding box of their centroids, and the max id.
        const int dim = GridView::dimension;
        typedef typename GridView::template Codim<0>::Iterator CI;
        typedef typename GridView::IntersectionIterator FI;
        typedef Dune::FieldVector<double, dim> Vector;
        std::vector<FI> bface_iters;
        Vector low(1e100);
        Vector hi(-1e100);
        int max_bid = 0;
        for (CI c = g.template begin<0>(); c != g.template end<0>(); ++c) {
            for (FI f = g.ibegin(*c); f != g.iend(*c); ++f) {
                if (f->boundaryId()) {
                    bface_iters.push_back(f);
                    Vector fcent = f->geometry().center();
                    for (int dd = 0; dd < dim; ++dd) {
                        low[dd] = std::min(low[dd], fcent[dd]);
                        hi[dd] = std::max(hi[dd], fcent[dd]);
                    }
                    max_bid = std::max(max_bid, f->boundaryId());
                }
            }
        }
        int num_bdy = bface_iters.size();
        if (max_bid != num_bdy) {
            OPM_THROW(std::runtime_error, "createPeriodic() assumes that every boundary face has a unique boundary id. That seems to be violated.");
        }

        // Store boundary face info in a suitable structure. Also find side total volumes.
    std::ranges::fill(side_areas, 0.0);
        bfinfo.clear();
        bfinfo.reserve(num_bdy);
        for (int i = 0; i < num_bdy; ++i) {
            BoundaryFaceInfo bf;
            bf.face_index = i;
            bf.bid = bface_iters[i]->boundaryId();
            bf.canon_pos = -1;
            bf.partner_face_index = -1;
            bf.partner_bid = 0;
            bf.area = bface_iters[i]->geometry().volume();
            bf.centroid = bface_iters[i]->geometry().center();
            for (int dd = 0; dd < dim; ++dd) {
                double coord = bf.centroid[dd];
                if (fabs(coord - low[dd]) <= spatial_tolerance) {
                    bf.canon_pos = 2*dd;
                    break;
                } else if (fabs(coord - hi[dd]) <= spatial_tolerance) {
                    bf.canon_pos = 2*dd + 1;
                    break;
                }
            }
            if (bf.canon_pos == -1) {
                std::cerr << "Centroid: " << bf.centroid << "\n";
                std::cerr << "Bounding box min: " << low << "\n";
                std::cerr << "Bounding box max: " << hi << "\n";
                OPM_THROW(std::runtime_error, "Boundary face centroid not on bounding box. Maybe the grid is not an axis-aligned shoe-box?");
            }
            side_areas[bf.canon_pos] += bf.area;
            bf.centroid[bf.canon_pos/2] = 0.0;
            bfinfo.push_back(bf);
        }
        assert(bfinfo.size() == bface_iters.size());

        // Sort the infos so that partners end up close.
        std::sort(bfinfo.begin(), bfinfo.end());

        // Identify partners.
        for (int i = 0; i < num_bdy; ++i) {
            if (bfinfo[i].partner_face_index != -1) {
                continue;
            }
            if (!is_periodic[bfinfo[i].canon_pos]) {
                continue;
            }
            int lower = std::max(0, i - 10);
            int upper = std::min(num_bdy, i + 10);
            bool ok = match(bfinfo, i, lower, upper);
            if (!ok) {
                // We have not found a partner.
                ok = match(bfinfo, i, 0, num_bdy);
                if (!ok) {
                    OPM_MESSAGE("Warning: No partner found for boundary id " << bfinfo[i].bid);
                    // OPM_THROW(std::runtime_error, "No partner found.");
                }
            }
        }
    }

    /*
    template <class GridInterface>
    void findPeriodicPartners(std::vector<BoundaryFaceInfo>& bfinfo,
                              std::array<double, 6>& side_areas,
                              const GridInterface& g,
                              const std::array<bool, 2*GridInterface::Dimension>& is_periodic,
                              double spatial_tolerance = 1e-6)
    {
        // Pick out all boundary faces, simultaneously find the
        // bounding box of their centroids, and the max id.
        typedef typename GridInterface::CellIterator CI;
        typedef typename CI::FaceIterator FI;
        typedef typename GridInterface::Vector Vector;
        std::vector<FI> bface_iters;
        Vector low(1e100);
        Vector hi(-1e100);
        int max_bid = 0;
        for (CI c = g.cellbegin(); c != g.cellend(); ++c) {
            for (FI f = c->facebegin(); f != c->faceend(); ++f) {
                if (f->boundaryId()) {
                    bface_iters.push_back(f);
                    Vector fcent = f->centroid();
                    for (int dd = 0; dd < GridInterface::Dimension; ++dd) {
                        low[dd] = std::min(low[dd], fcent[dd]);
                        hi[dd] = std::max(hi[dd], fcent[dd]);
                    }
                    max_bid = std::max(max_bid, f->boundaryId());
                }
            }
        }
        int num_bdy = bface_iters.size();
        if (max_bid != num_bdy) {
            OPM_THROW(std::runtime_error, "createPeriodic() assumes that every boundary face has a unique boundary id. That seems to be violated.");
        }

        // Store boundary face info in a suitable structure. Also find side total volumes.
    std::ranges::fill(side_areas, 0.0);
        bfinfo.clear();
        bfinfo.reserve(num_bdy);
        for (int i = 0; i < num_bdy; ++i) {
            BoundaryFaceInfo bf;
            bf.face_index = i;
            bf.bid = bface_iters[i]->boundaryId();
            bf.canon_pos = -1;
            bf.partner_face_index = -1;
            bf.partner_bid = 0;
            bf.area = bface_iters[i]->area();
            bf.centroid = bface_iters[i]->centroid();
            for (int dd = 0; dd < GridInterface::Dimension; ++dd) {
                double coord = bf.centroid[dd];
                if (fabs(coord - low[dd]) <= spatial_tolerance) {
                    bf.canon_pos = 2*dd;
                    break;
                } else if (fabs(coord - hi[dd]) <= spatial_tolerance) {
                    bf.canon_pos = 2*dd + 1;
                    break;
                }
            }
            if (bf.canon_pos == -1) {
                std::cerr << "Centroid: " << bf.centroid << "\n";
                std::cerr << "Bounding box min: " << low << "\n";
                std::cerr << "Bounding box max: " << hi << "\n";
                OPM_THROW(std::runtime_error, "Boundary face centroid not on bounding box. Maybe the grid is not an axis-aligned shoe-box?");
            }
            side_areas[bf.canon_pos] += bf.area;
            bf.centroid[bf.canon_pos/2] = 0.0;
            bfinfo.push_back(bf);
        }
        assert(bfinfo.size() == bface_iters.size());

        // Sort the infos so that partners end up close.
        std::sort(bfinfo.begin(), bfinfo.end());

        // Identify partners.
        for (int i = 0; i < num_bdy; ++i) {
            if (bfinfo[i].partner_face_index != -1) {
                continue;
            }
            if (!is_periodic[bfinfo[i].canon_pos]) {
                continue;
            }
            int lower = std::max(0, i - 10);
            int upper = std::min(num_bdy, i + 10);
            bool ok = match(bfinfo, i, lower, upper);
            if (!ok) {
                // We have not found a partner.
                ok = match(bfinfo, i, 0, num_bdy);
                if (!ok) {
                    OPM_MESSAGE("Warning: No partner found for boundary id " << bfinfo[i].bid);
                    // OPM_THROW(std::runtime_error, "No partner found.");
                }
            }
        }
    }
*/



} // namespace Opm

#endif // OPM_BOUNDARYPERIODICITY_HEADER_INCLUDED