Tetraedre.cpp

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#include <Tetraedre.h>
#include <Domaine.h>
#include <Linear_algebra_tools_impl.h>
#include <algorithm>
using std::swap;
 
Implemente_instanciable_32_64(Tetraedre_32_64,"Tetraedre",Elem_geom_base_32_64<_T_>);
 
static int faces_sommets_tetra[4][3] =
{
  { 1, 2, 3 },
  { 2, 3, 0 },
  { 3, 0, 1 },
  { 0, 1, 2 }
};
 
template <typename _SIZE_>
Sortie& Tetraedre_32_64<_SIZE_>::printOn(Sortie& s ) const
{
  return s;
}
 
template <typename _SIZE_>
Entree& Tetraedre_32_64<_SIZE_>::readOn(Entree& s )
{
  return s;
}
 
 
/*! @brief Returns the LML name of a tetrahedron = "TETRA4".
 *
 * @return Always equal to "TETRA4".
 */
template <typename _SIZE_>
const Nom& Tetraedre_32_64<_SIZE_>::nom_lml() const
{
  static Nom nom="TETRA4";
  return nom;
}
 
 
namespace
{
/*! @brief tests if 2 points are on the same side of a plane defined by three points
*
* Takes the coordinates of all points involved as arguments (5 points, so 15 arguments)
* The order is X, Y, Z coord of a point, then next point
*
* The first nine arguments are for the points defining the plane (X/Y/Z 0 to 2)
*
* The next 6 describe the point for which we want to test they are on the same side (X3/Y3/Z3 and Mx/My/Mz)
*
* The use case is testing if a point M is inside a tetrahedra.
* To do that, call this function 4 times in a row while cycling the first 4 points,
* which must correspond to the 4 vertexes of the tetrahedra,
* as done in function Tetraedre_32_64<_SIZE_>::contient
* (hence the names of the arguments, which may be confusing for a different use case)
*
*
*
* @return 1 if the point belongs to the tetrahedron, 0 otherwise.
*/
inline bool is_on_same_side_of_plane(const double& X0, const double& Y0, const double& Z0,
                                     const double& X1, const double& Y1, const double& Z1,
                                     const double& X2, const double& Y2, const double& Z2,
                                     const double& X3, const double& Y3, const double& Z3,
                                     const double& Mx, const double& My, const double& Mz
                                    )
{
 
  // computes the normal vector of the plane
  double xn = (Y1 - Y0) * (Z2 - Z0) - (Z1 - Z0) * (Y2 - Y0);
  double yn = (Z1 - Z0) * (X2 - X0) - (X1 - X0) * (Z2 - Z0);
  double zn = (X1 - X0) * (Y2 - Y0) - (Y1 - Y0) * (X2 - X0);
 
  // computes the scalar product between normal vector and a vector from the plane to each of the points we want to test
  double prod1 = xn * (X3 - X0) + yn * (Y3 - Y0) + zn * (Z3 - Z0);
  double prod2 = xn * (Mx - X0) + yn * (My - Y0) + zn * (Mz - Z0);
 
  // if scalar products have the same sign, the points are on the same sides
  // we allow a slight tolerance for points very close to the plane
  if (prod1 * prod2 < 0 && std::fabs(prod2)>std::fabs(prod1)*Objet_U::precision_geom)
    {
      return false;
    }
  else
    {
      return true;
    }
}
}
 
/*! @brief Returns 1 if element "ielem" of the domain associated with this geometric element contains the point with coordinates "pos". Returns 0 otherwise.
 *
 * @param pos Coordinates of the point to locate.
 * @param ielem Index of the domain element in which to search for the point.
 * @return 1 if the point belongs to element "ielem", 0 otherwise.
 */
template <typename _SIZE_>
int Tetraedre_32_64<_SIZE_>::contient(const ArrOfDouble& pos, int_t ielem) const
{
  // 29/01/2010 CPU optimisation of this method (50% faster) by PL
  assert(pos.size_array()==3);
  const Domaine_t& domaine=mon_dom.valeur();
  const DoubleTab_t& coord=domaine.coord_sommets();
 
  int_t som0 = domaine.sommet_elem(ielem,0);
  int_t som1 = domaine.sommet_elem(ielem,1);
  int_t som2 = domaine.sommet_elem(ielem,2);
  int_t som3 = domaine.sommet_elem(ielem,3);
  double X0 = coord(som0,0);
  double Y0 = coord(som0,1);
  double Z0 = coord(som0,2);
  double X1 = coord(som1,0);
  double Y1 = coord(som1,1);
  double Z1 = coord(som1,2);
  double X2 = coord(som2,0);
  double Y2 = coord(som2,1);
  double Z2 = coord(som2,2);
  double X3 = coord(som3,0);
  double Y3 = coord(som3,1);
  double Z3 = coord(som3,2);
 
  // Here we used to test if the point was one of the vertexes of the tetra using est_egal
  // probably not worth it, happened in 0.03% of test cases according to gcov
  // must mean we rarely lookup for a point of the mesh using this function
 
 
  // However, it might be worth to check a simpler distance to center of tetra first
  // Using some bound at which we are certain the point is outside (one that is easier to compute than circumradius preferably, don't know if that exists)
  // depending on usage of this function, may avoid testing on each face in a lot of cases
 
  // Now we do the real work
  // For a point to be inside a tetra, for each face made of three of the 4 vertexes
  // the point must be on the same side as the fourth vertex
  // We test that with the function is_on_same_side_of_plane defined in this file
 
 
  // test som3 and pos are on same side
  if (not is_on_same_side_of_plane(X0, Y0, Z0, X1, Y1, Z1, X2, Y2, Z2, X3, Y3, Z3, pos[0], pos[1], pos[2]))
    {
      return false;
    }
 
  // test som2 and pos are on same side
  if (not is_on_same_side_of_plane(X3, Y3, Z3, X0, Y0, Z0, X1, Y1, Z1, X2, Y2, Z2, pos[0], pos[1], pos[2]))
    {
      return false;
    }
 
  // test som1 and pos are on same side
  if (not is_on_same_side_of_plane(X2, Y2, Z2, X3, Y3, Z3, X0, Y0, Z0, X1, Y1, Z1, pos[0], pos[1], pos[2]))
    {
      return false;
    }
 
  // test som0 and pos are on same side
  if (not is_on_same_side_of_plane(X1, Y1, Z1, X2, Y2, Z2, X3, Y3, Z3, X0, Y0, Z0, pos[0], pos[1], pos[2]))
    {
      return false;
    }
 
  return true;
 
}
 
 
/*! @brief Returns 1 if the vertices specified by "som" are the vertices of element "element"
 *
 * in the domain associated with this geometric element. Returns 0 otherwise.
 *
 * @param som Vertex indices to compare with those of element "element".
 * @param element Index of the domain element whose vertices are to be compared.
 * @return 1 if the specified vertices are those of the given element, 0 otherwise.
 */
template <typename _SIZE_>
int Tetraedre_32_64<_SIZE_>::contient(const SmallArrOfTID_t& som, int_t element ) const
{
  const Domaine_t& domaine=mon_dom.valeur();
  if((domaine.sommet_elem(element,0)==som[0])&&
      (domaine.sommet_elem(element,1)==som[1])&&
      (domaine.sommet_elem(element,1)==som[2])&&
      (domaine.sommet_elem(element,1)==som[3]))
    return 1;
  else
    return 0;
}
 
/*! @brief Computes the volumes of the elements of the associated domain.
 *
 * @param tab_volumes Vector to fill with the volumes of domain elements.
 */
template <typename _SIZE_>
void Tetraedre_32_64<_SIZE_>::calculer_volumes(DoubleVect_t& tab_volumes) const
{
  const Domaine_t& domaine=mon_dom.valeur();
 
  int_t size_tot = domaine.nb_elem_tot();
  assert(tab_volumes.size_totale()==size_tot);
  ConstView<_SIZE_,2> les_Polys = domaine.les_elems().view_ro();
  CDoubleTabView coord = domaine.coord_sommets().view_ro();
  auto volumes = tab_volumes.view_wo();
  Kokkos::parallel_for(start_gpu_timer(__KERNEL_NAME__), size_tot, KOKKOS_LAMBDA(const int_t num_poly)
  {
    int_t s0 = les_Polys(num_poly, 0);
    int_t s1 = les_Polys(num_poly, 1);
    int_t s2 = les_Polys(num_poly, 2);
    int_t s3 = les_Polys(num_poly, 3);
    double x0 = coord(s0, 0), y0 = coord(s0, 1), z0 = coord(s0, 2);
    double x1 = coord(s1, 0), y1 = coord(s1, 1), z1 = coord(s1, 2);
    double x2 = coord(s2, 0), y2 = coord(s2, 1), z2 = coord(s2, 2);
    double x3 = coord(s3, 0), y3 = coord(s3, 1), z3 = coord(s3, 2);
    volumes(num_poly) = Kokkos::fabs((x1-x0)*((y2-y0)*(z3-z0)-(y3-y0)*(z2-z0))-
                                     (x2-x0)*((y1-y0)*(z3-z0)-(y3-y0)*(z1-z0))+
                                     (x3-x0)*((y1-y0)*(z2-z0)-(y2-y0)*(z1-z0)))/6;
  });
  end_gpu_timer(__KERNEL_NAME__);
}
 
 
/*! @brief Computes the face normals of the elements of the associated domain.
 *
 * @param Face_sommets Vertex indices of the faces in the domain vertex list.
 * @param face_normales Output array to fill with face normals.
 */
template <typename _SIZE_>
void Tetraedre_32_64<_SIZE_>::calculer_normales(const IntTab_t& Face_sommets, DoubleTab_t& face_normales) const
{
  const Domaine_t& domaine_geom = mon_dom.valeur();
  const DoubleTab_t& les_coords = domaine_geom.coord_sommets();
  int_t nbfaces = Face_sommets.dimension(0);
  for (int_t numface=0; numface<nbfaces; numface++)
    {
 
      int_t n0 = Face_sommets(numface,0);
      int_t n1 = Face_sommets(numface,1);
      int_t n2 = Face_sommets(numface,2);
 
      double x1 = les_coords(n0,0) - les_coords(n1,0);
      double y1 = les_coords(n0,1) - les_coords(n1,1);
      double z1 = les_coords(n0,2) - les_coords(n1,2);
 
      double x2 = les_coords(n2,0) - les_coords(n1,0);
      double y2 = les_coords(n2,1) - les_coords(n1,1);
      double z2 = les_coords(n2,2) - les_coords(n1,2);
 
      face_normales(numface,0) = (y1*z2 - y2*z1)/2;
      face_normales(numface,1) = (-x1*z2 + x2*z1)/2;
      face_normales(numface,2) = (x1*y2 - x2*y1)/2;
    }
}
 
/*! @brief See ElemGeomBase::get_tab_faces_sommets_locaux.
 */
template <typename _SIZE_>
int Tetraedre_32_64<_SIZE_>::get_tab_faces_sommets_locaux(IntTab& faces_som_local) const
{
  // a tetrahedron has four faces of three vertices each
  faces_som_local.resize(4,3);
  for (int i=0; i<4; i++)
    for (int j=0; j<3; j++)
      faces_som_local(i,j) = faces_sommets_tetra[i][j];
  return 1;
}
 
template <typename _SIZE_>
void Tetraedre_32_64<_SIZE_>::get_tab_aretes_sommets_locaux(IntTab& tab) const
{
  // a tetrahedron has six edges of two vertices each
  tab.resize(6, 2);
  int count = 0;
  // one edge between each pair of tetra vertices: n * (n-1) / 2 edges with n=4
  for (int i = 0; i < 3; i++)
    {
      for (int j = i + 1; j < 4; j++)
        {
          tab(count, 0) = i;
          tab(count, 1) = j;
          count++;
        }
    }
  assert(count == 6);
}
 
 
///*! Computes the barycentric coordinate in a tetrahedron corresponding to a
// * Cartesian coordinate "point". Note: if "point" is outside the tetra, one or more
// * barycentric coordinates will be negative.
// * polys is the tetrahedron connectivity table (vertex indices),
// * coords is the vertex coordinate table,
// * le_poly is the tetrahedron index whose barycentric coordinates are to be computed.
// *
// * The result is stored in coord_bary (weights of the first three vertices,
// * the fourth being implicitly 1 minus the sum of the other three).
// * If epsilon is non-zero, the return value is the uncertainty on the barycentric
// * coordinates for an uncertainty epsilon on the Cartesian coordinates.
// * (computed in Linfini norm, i.e. the max error over each component)
// */
//template <typename _SIZE_>
//double Tetraedre_32_64<_SIZE_>::coord_bary(const IntTab& polys, const DoubleTab& coords,
//                             const Vecteur3& point, int le_poly, Vecteur3& coord_bary, double epsilon)
//{
//  Matrice33 m;
//  Vecteur3 origine;
//  matrice_base_tetraedre(polys, coords, le_poly, m, origine);
//  Matrice33 inverse_m;
//  Matrice33::inverse(m, inverse_m);
//  Vecteur3 v(point-origine);
//  Matrice33::produit(inverse_m, v, coord_bary);
//
//  double resu;
//  if (epsilon > 0.)
//    {
//      // An error epsilon on the "point" coordinate results in an error on coord_bary:
//      double norm = inverse_m.norme_Linfini();
//      resu = norm * epsilon;
//    }
//  else
//    {
//      resu = 0.;
//    }
//  return resu;
//}
 
 
template class Tetraedre_32_64<int>;
#if INT_is_64_ == 2
template class Tetraedre_32_64<trustIdType>;
#endif