IntxRllCssphere.cpp

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/*
 * IntxRllCssphere.cpp
 *
 *  Created on: Aug 8, 2014
 *      Author: iulian
 */
 
#include "moab/IntxMesh/IntxRllCssphere.hpp"
#include "moab/GeomUtil.hpp"
#include "moab/IntxMesh/IntxUtils.hpp"
 
namespace moab
{
 
IntxRllCssphere::IntxRllCssphere( Interface* mbimpl ) : Intx2Mesh( mbimpl ), R( 0.0 ), plane( 0 ) {}
 
IntxRllCssphere::~IntxRllCssphere() {}
 
/*
 * return also the area for robustness verification
 */
double IntxRllCssphere::setup_tgt_cell( EntityHandle tgt, int& nsTgt )
{
    // get coordinates of the tgt quad, to decide the gnomonic plane
    double cellArea = 0;
 
    int num_nodes;
    ErrorCode rval = mb->get_connectivity( tgt, tgtConn, num_nodes );
 
    if( MB_SUCCESS != rval ) return 1;
    nsTgt = num_nodes;
    // these edges will never be polygons, only quads or triangles
 
    // CartVect coords[4];
    rval = mb->get_coords( tgtConn, nsTgt, &( tgtCoords[0][0] ) );
    if( MB_SUCCESS != rval ) return 1;
    CartVect middle = tgtCoords[0];
    for( int i = 1; i < nsTgt; i++ )
        middle += tgtCoords[i];
    middle = 1. / nsTgt * middle;
 
    IntxUtils::decide_gnomonic_plane( middle, plane );  // output the plane
    for( int j = 0; j < nsTgt; j++ )
    {
        // populate coords in the plane for intersection
        // they should be oriented correctly, positively
        int rc = IntxUtils::gnomonic_projection( tgtCoords[j], R, plane, tgtCoords2D[2 * j], tgtCoords2D[2 * j + 1] );
        if( rc != 0 ) return 1;
    }
 
    for( int j = 1; j < nsTgt - 1; j++ )
        cellArea += IntxUtils::area2D( &tgtCoords2D[0], &tgtCoords2D[2 * j], &tgtCoords2D[2 * j + 2] );
 
    // take tgt coords in order and compute area in plane
    return cellArea;
}
 
/* the elements are convex for sure, then do a gnomonic projection of both,
 *  compute intersection in the plane, then go back to the sphere for the points
 *  */
ErrorCode IntxRllCssphere::computeIntersectionBetweenTgtAndSrc( EntityHandle tgt,
                                                                EntityHandle src,
                                                                double* P,
                                                                int& nP,
                                                                double& area,
                                                                int markb[MAXEDGES],
                                                                int markr[MAXEDGES],
                                                                int& nsSrc,
                                                                int& nsTgt,
                                                                bool check_boxes_first )
{
    // the area will be used from now on, to see how well we fill the tgt cell with polygons
    // the points will be at most 40; they will describe a convex patch, after the points will be
    // ordered and collapsed (eliminate doubles)
 
    // CartVect srccoords[4];
    int num_nodes = 0;
    MB_CHK_ERR( mb->get_connectivity( src, srcConn, num_nodes ) );
 
    nsSrc = num_nodes;
    MB_CHK_ERR( mb->get_coords( srcConn, nsSrc, &( srcCoords[0][0] ) ) );
 
    // determine the type of edge: const lat or not?
    // just look at the consecutive z coordinates for the edge
    for( int i = 0; i < nsSrc; i++ )
    {
        int nexti = ( i + 1 ) % nsSrc;
        if( fabs( srcCoords[i][2] - srcCoords[nexti][2] ) < 1.e-6 )
            srcEdgeType[i] = 1;
        else
            srcEdgeType[i] = 0;
    }
    area = 0.;
    nP   = 0;  // number of intersection points we are marking the boundary of src!
    if( check_boxes_first )
    {
        // look at the boxes formed with vertices; if they are far away, return false early
        // make sure the tgt is setup already
        setup_tgt_cell( tgt, nsTgt );  // we do not need area here
        if( !GeomUtil::bounding_boxes_overlap( tgtCoords, nsTgt, srcCoords, nsSrc, box_error ) )
            return MB_SUCCESS;  // no error, but no intersection, decide early to get out
    }
#ifdef ENABLE_DEBUG
    if( dbg_1 )
    {
        std::cout << "tgt " << mb->id_from_handle( tgt ) << "\n";
        for( int j = 0; j < nsTgt; j++ )
        {
            std::cout << tgtCoords[j] << "\n";
        }
        std::cout << "src " << mb->id_from_handle( src ) << "\n";
        for( int j = 0; j < nsSrc; j++ )
        {
            std::cout << srcCoords[j] << "\n";
        }
        mb->list_entities( &tgt, 1 );
        mb->list_entities( &src, 1 );
    }
#endif
    for( int j = 0; j < nsSrc; j++ )
    {
        MB_CHK_ERR(
            IntxUtils::gnomonic_projection( srcCoords[j], R, plane, srcCoords2D[2 * j], srcCoords2D[2 * j + 1] ) );
    }
#ifdef ENABLE_DEBUG
    if( dbg_1 )
    {
        std::cout << "gnomonic plane: " << plane << "\n";
        std::cout << " tgt                                src\n";
        for( int j = 0; j < nsTgt; j++ )
        {
            std::cout << tgtCoords2D[2 * j] << " " << tgtCoords2D[2 * j + 1] << "\n";
        }
        for( int j = 0; j < nsSrc; j++ )
        {
            std::cout << srcCoords2D[2 * j] << " " << srcCoords2D[2 * j + 1] << "\n";
        }
    }
#endif
    MB_CHK_ERR( IntxUtils::EdgeIntxRllCs( srcCoords2D, srcCoords, srcEdgeType, nsSrc, tgtCoords2D, tgtCoords, nsTgt,
                                          markb, markr, plane, R, P, nP ) );
 
    int side[MAXEDGES] = { 0 };  // this refers to what side? src or tgt?// more tolerant here with epsilon_area
    int extraPoints    = IntxUtils::borderPointsOfXinY2( srcCoords2D, nsSrc, tgtCoords2D, nsTgt, &( P[2 * nP] ), side,
                                                         2 * epsilon_area );
    if( extraPoints >= 1 )
    {
        for( int k = 0; k < nsSrc; k++ )
        {
            if( side[k] )
            {
                // this means that vertex k of src is inside convex tgt; mark edges k-1 and k in
                // src,
                //   as being "intersected" by tgt; (even though they might not be intersected by
                //   other edges, the fact that their apex is inside, is good enough)
                markb[k] = 1;
                markb[( k + nsSrc - 1 ) % nsSrc] =
                    1;  // it is the previous edge, actually, but instead of doing -1, it is
                // better to do modulo +3 (modulo 4)
                // null side b for next call
                side[k] = 0;
            }
        }
    }
    nP += extraPoints;
 
    extraPoints =
        IntxUtils::borderPointsOfCSinRLL( tgtCoords, tgtCoords2D, nsTgt, srcCoords, nsSrc, srcEdgeType, &( P[2 * nP] ),
                                          side,
                                          100 * epsilon_area );  // we need to compare with 0 a volume from 3 vector
                                                                 // product; // lots of round off errors at stake
    if( extraPoints >= 1 )
    {
        for( int k = 0; k < nsTgt; k++ )
        {
            if( side[k] )
            {
                // this is to mark that tgt edges k-1 and k are intersecting src
                markr[k] = 1;
                markr[( k + nsTgt - 1 ) % nsTgt] =
                    1;  // it is the previous edge, actually, but instead of doing -1, it is
                // better to do modulo +3 (modulo 4)
                // null side b for next call
            }
        }
    }
    nP += extraPoints;
 
    // now sort and orient the points in P, such that they are forming a convex polygon
    // this will be the foundation of our new mesh
    // this works if the polygons are convex
    IntxUtils::SortAndRemoveDoubles2( P, nP, epsilon_1 );  // nP should be at most 8 in the end ?
    // if there are more than 3 points, some area will be positive
 
    if( nP >= 3 )
    {
        for( int k = 1; k < nP - 1; k++ )
            area += IntxUtils::area2D( P, &P[2 * k], &P[2 * k + 2] );
    }
 
    return MB_SUCCESS;  // no error
}
 
// this method will also construct the triangles/polygons in the new mesh
// if we accept planar polygons, we just save them
// also, we could just create new vertices every time, and merge only in the end;
// could be too expensive, and the tolerance for merging could be an
// interesting topic
ErrorCode IntxRllCssphere::findNodes( EntityHandle tgt, int nsTgt, EntityHandle src, int nsSrc, double* iP, int nP )
{
    // first of all, check against tgt and src vertices
    //
#ifdef ENABLE_DEBUG
    if( dbg_1 )
    {
        std::cout << "tgt, src, nP, P " << mb->id_from_handle( tgt ) << " " << mb->id_from_handle( src ) << " " << nP
                  << "\n";
        for( int n = 0; n < nP; n++ )
            std::cout << " \t" << iP[2 * n] << "\t" << iP[2 * n + 1] << "\n";
    }
#endif
 
    // get the edges for the tgt triangle; the extra points will be on those edges, saved as
    // lists (unordered)
 
    // first get the list of edges adjacent to the tgt cell
    // use the neighTgtEdgeTag
    EntityHandle adjTgtEdges[MAXEDGES];
    MB_CHK_SET_ERR( mb->tag_get_data( neighTgtEdgeTag, &tgt, 1, &( adjTgtEdges[0] ) ), "can't get edge tgt tag" );
    // we know that we have only nsTgt edges here; [nsTgt, MAXEDGES) are ignored, but it is small
    // potatoes
 
    // these will be in the new mesh, mbOut
    // some of them will be handles to the initial vertices from src or tgt meshes (lagr or euler)
 
    EntityHandle* foundIds = new EntityHandle[nP];
    for( int i = 0; i < nP; i++ )
    {
        double* pp = &iP[2 * i];  // iP+2*i
        // project the point back on the sphere
        CartVect pos;
        IntxUtils::reverse_gnomonic_projection( pp[0], pp[1], R, plane, pos );
        int found = 0;
        // first, are they on vertices from tgt or src?
        // priority is the tgt mesh (mb2?)
        int j                = 0;
        EntityHandle outNode = (EntityHandle)0;
        for( j = 0; j < nsTgt && !found; j++ )
        {
            // int node = tgtTri.v[j];
            double d2 = IntxUtils::dist2( pp, &tgtCoords2D[2 * j] );
            if( d2 < epsilon_1 )
            {
 
                foundIds[i] = tgtConn[j];  // no new node
                found       = 1;
#ifdef ENABLE_DEBUG
                if( dbg_1 )
                    std::cout << "  tgt node j:" << j << " id:" << mb->id_from_handle( tgtConn[j] )
                              << " 2d coords:" << tgtCoords2D[2 * j] << "  " << tgtCoords2D[2 * j + 1] << " d2: " << d2
                              << " \n";
#endif
            }
        }
 
        for( j = 0; j < nsSrc && !found; j++ )
        {
            // int node = srcTri.v[j];
            double d2 = IntxUtils::dist2( pp, &srcCoords2D[2 * j] );
            if( d2 < epsilon_1 )
            {
                // suspect is srcConn[j] corresponding in mbOut
 
                foundIds[i] = srcConn[j];  // no new node
                found       = 1;
#ifdef ENABLE_DEBUG
                if( dbg_1 )
                    std::cout << "  src node " << j << " " << mb->id_from_handle( srcConn[j] ) << " d2:" << d2 << " \n";
#endif
            }
        }
        if( !found )
        {
            // find the edge it belongs, first, on the tgt element
            //
            for( j = 0; j < nsTgt; j++ )
            {
                int j1      = ( j + 1 ) % nsTgt;
                double area = IntxUtils::area2D( &tgtCoords2D[2 * j], &tgtCoords2D[2 * j1], pp );
#ifdef ENABLE_DEBUG
                if( dbg_1 )
                    std::cout << "   edge " << j << ": " << mb->id_from_handle( adjTgtEdges[j] ) << " " << tgtConn[j]
                              << " " << tgtConn[j1] << "  area : " << area << "\n";
#endif
                if( fabs( area ) < epsilon_1 / 2 )
                {
                    // found the edge; now find if there is a point in the list here
                    // std::vector<EntityHandle> * expts = extraNodesMap[tgtEdges[j]];
                    int indx = TgtEdges.index( adjTgtEdges[j] );
                    // CID 181167 (#1 of 1): Argument cannot be negative (NEGATIVE_RETURNS)
                    if( indx < 0 )
                    {
                        std::cerr << " error in adjacent tgt edge: " << mb->id_from_handle( adjTgtEdges[j] ) << "\n";
                        delete[] foundIds;
                        return MB_FAILURE;
                    }
                    std::vector< EntityHandle >* expts = extraNodesVec[indx];
                    // if the points pp is between extra points, then just give that id
                    // if not, create a new point, (check the id)
                    // get the coordinates of the extra points so far
                    int nbExtraNodesSoFar = expts->size();
                    if( nbExtraNodesSoFar > 0 )
                    {
                        CartVect* coords1 = new CartVect[nbExtraNodesSoFar];
                        mb->get_coords( &( *expts )[0], nbExtraNodesSoFar, &( coords1[0][0] ) );
                        // std::list<int>::iterator it;
                        for( int k = 0; k < nbExtraNodesSoFar && !found; k++ )
                        {
                            // int pnt = *it;
                            double d2 = ( pos - coords1[k] ).length_squared();
                            if( d2 < epsilon_1 )
                            {
                                found       = 1;
                                foundIds[i] = ( *expts )[k];
#ifdef ENABLE_DEBUG
                                if( dbg_1 ) std::cout << " found node:" << foundIds[i] << std::endl;
#endif
                            }
                        }
                        delete[] coords1;
                    }
                    if( !found )
                    {
                        // create a new point in 2d (at the intersection)
                        // foundIds[i] = m_num2dPoints;
                        // expts.push_back(m_num2dPoints);
                        // need to create a new node in mbOut
                        // this will be on the edge, and it will be added to the local list
                        mb->create_vertex( pos.array(), outNode );
                        ( *expts ).push_back( outNode );
                        foundIds[i] = outNode;
                        found       = 1;
#ifdef ENABLE_DEBUG
                        if( dbg_1 ) std::cout << " new node: " << outNode << std::endl;
#endif
                    }
                }
            }
        }
        if( !found )
        {
            std::cout << " tgt quad: ";
            for( int j1 = 0; j1 < nsTgt; j1++ )
            {
                std::cout << tgtCoords2D[2 * j1] << " " << tgtCoords2D[2 * j1 + 1] << "\n";
            }
            std::cout << " a point pp is not on a tgt quad " << *pp << " " << pp[1] << " tgt quad "
                      << mb->id_from_handle( tgt ) << " \n";
            delete[] foundIds;
            return MB_FAILURE;
        }
    }
#ifdef ENABLE_DEBUG
    if( dbg_1 )
    {
        std::cout << " candidate polygon: nP" << nP << " plane: " << plane << "\n";
        for( int i1 = 0; i1 < nP; i1++ )
            std::cout << iP[2 * i1] << " " << iP[2 * i1 + 1] << " " << foundIds[i1] << "\n";
    }
#endif
    // first, find out if we have nodes collapsed; shrink them
    // we may have to reduce nP
    // it is possible that some nodes are collapsed after intersection only
    // nodes will always be in order (convex intersection)
    correct_polygon( foundIds, nP );
    // now we can build the triangles, from P array, with foundIds
    // we will put them in the out set
    if( nP >= 3 )
    {
        EntityHandle polyNew;
        mb->create_element( MBPOLYGON, foundIds, nP, polyNew );
        mb->add_entities( outSet, &polyNew, 1 );
 
        // tag it with the index ids from tgt and src sets
        int id = rs1.index( src );  // index starts from 0
        mb->tag_set_data( srcParentTag, &polyNew, 1, &id );
        id = rs2.index( tgt );
        mb->tag_set_data( tgtParentTag, &polyNew, 1, &id );
 
        counting++;
        mb->tag_set_data( countTag, &polyNew, 1, &counting );
 
#ifdef ENABLE_DEBUG
        if( dbg_1 )
        {
 
            std::cout << "Counting: " << counting << "\n";
            std::cout << " polygon " << mb->id_from_handle( polyNew ) << "  nodes: " << nP << " :";
            for( int i1 = 0; i1 < nP; i1++ )
                std::cout << " " << mb->id_from_handle( foundIds[i1] );
            std::cout << " plane: " << plane << "\n";
            std::vector< CartVect > posi( nP );
            mb->get_coords( foundIds, nP, &( posi[0][0] ) );
            for( int i1 = 0; i1 < nP; i1++ )
                std::cout << foundIds[i1] << " " << posi[i1] << "\n";
 
            std::stringstream fff;
            fff << "file0" << counting << ".vtk";
            mb->write_mesh( fff.str().c_str(), &outSet, 1 );
        }
#endif
    }
    // disable_debug();
    delete[] foundIds;
    foundIds = nullptr;
    return MB_SUCCESS;
}
 
} /* namespace moab */