Triangle.h

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#ifndef Triangle_included
#define Triangle_included
 
#include <Elem_geom_base.h>
#include <TRUSTTab.h>
 
/*! @brief Class Triangle: represents the geometric element Triangle.
 *
 *     A triangle has 3 faces, 3 vertices, and a single face type with
 *     2 vertices per face.
 *
 * @sa Elem_geom_base Elem_geom
 */
template <typename _SIZE_>
class Triangle_32_64 : public Elem_geom_base_32_64<_SIZE_>
{
 
  Declare_instanciable_32_64(Triangle_32_64);
 
public :
 
  using int_t = _SIZE_;
  using IntTab_t = IntTab_T<_SIZE_>;
  using SmallArrOfTID_t = SmallArrOfTID_T<_SIZE_>;
  using DoubleVect_t = DoubleVect_T<_SIZE_>;
  using DoubleTab_t = DoubleTab_T<_SIZE_>;
  using Domaine_t = Domaine_32_64<_SIZE_>;
 
 
  inline int face_sommet(int i, int j) const override;
  inline int face_sommet0(int i) const;
  inline int face_sommet1(int i) const;
  inline int face_sommet2(int i) const;
  inline int nb_som() const override { return 3; }
  inline int nb_faces(int = 0) const override;
  inline int nb_som_face(int = 0) const override;
  inline bool est_structure() const override { return false; }
  const Nom& nom_lml() const override;
  int contient(const ArrOfDouble& pos, int_t elem) const override;
  int contient(const SmallArrOfTID_t& soms, int_t elem) const override;
  inline Type_Face type_face(int=0) const override;
  void calculer_volumes(DoubleVect_t& vols) const override;
  void calculer_normales(const IntTab_t& faces_sommets , DoubleTab_t& face_normales) const override;
  int get_tab_faces_sommets_locaux(IntTab& faces_som_local) const override;
 
protected:
  // Members herited from top classes:
  using Objet_U::dimension;
  using Elem_geom_base_32_64<_SIZE_>::mon_dom;
 
};
 
/*! Computes the area of a triangle in 2D or 3D.
 * Parameters passed:
 * pos: array containing the coordinates of the 3 vertices of the triangle
 */
inline double aire_triangle(const DoubleTab& pos)
{
  double x0 = pos(0,0);
  double y0 = pos(0,1);
  double x1 = pos(1,0);
  double y1 = pos(1,1);
  double x2 = pos(2,0);
  double y2 = pos(2,1);
  double dz = (x1-x0)*(y2-y0) - (x2-x0)*(y1-y0);
  if (Objet_U::dimension==2)
    return 0.5 * std::fabs(dz);
  else
    {
      double z0 = pos(0,2);
      double z1 = pos(1,2);
      double z2 = pos(2,2);
      double dx = (y1-y0)*(z2-z0) - (y2-y0)*(z1-z0);
      double dy = (z1-z0)*(x2-x0) - (x1-x0)*(z2-z0);
      return 0.5 * sqrt(dx*dx+dy*dy+dz*dz);
    }
}
 
/*! @brief Returns the index of the j-th vertex of the i-th face of the element.
 *
 * @param i a face index
 * @param j a vertex index
 * @return the index of the j-th vertex of the i-th face
 */
template <typename _SIZE_>
inline int Triangle_32_64<_SIZE_>::face_sommet(int i, int j) const
{
  assert(i<3);
  switch(i)
    {
    case 0:
      return face_sommet0(j);
    case 1:
      return face_sommet1(j);
    case 2:
      return face_sommet2(j);
    default :
      return -1;
    }
}
 
/*! @brief Returns the number of faces of the specified type that the geometric element has.
 *
 * @param i the face type
 * @return the number of faces of type i
 */
template <typename _SIZE_>
inline int Triangle_32_64<_SIZE_>::nb_faces(int i) const
{
  assert(i==0);
  return 3;
}
 
 
/*! @brief Returns the number of vertices of faces of the specified type.
 *
 * @param i the face type
 * @return the number of vertices of faces of type i
 */
template <typename _SIZE_>
inline int Triangle_32_64<_SIZE_>::nb_som_face(int i) const
{
  assert(i==0);
  return 2;
}
 
 
/*! @brief Returns the index of the i-th vertex of face 0.
 *
 * @param i the index of the vertex to return
 * @return the index of the i-th vertex of face 0
 */
template <typename _SIZE_>
inline int Triangle_32_64<_SIZE_>::face_sommet0(int i) const
{
  assert(i>=0);
  assert(i<2);
  return (i+1);
}
 
 
/*! @brief Returns the index of the i-th vertex of face 1.
 *
 * @param i the index of the vertex to return
 * @return the index of the i-th vertex of face 1
 */
template <typename _SIZE_>
inline int Triangle_32_64<_SIZE_>::face_sommet1(int i) const
{
  assert(i>=0);
  assert(i<2);
  return ((i+2)%3);
}
 
 
/*! @brief Returns the index of the i-th vertex of face 2.
 *
 * @param i the index of the vertex to return
 * @return the index of the i-th vertex of face 2
 */
template <typename _SIZE_>
inline int Triangle_32_64<_SIZE_>::face_sommet2(int i) const
{
  assert(i>=0);
  assert(i<2);
  return i;
}
 
 
/*! @brief Returns the i-th face type.
 *
 * A triangle has only one face type.
 *
 * @param i the rank of the face type to return
 * @return a face type
 */
template <typename _SIZE_>
inline Type_Face Triangle_32_64<_SIZE_>::type_face(int i) const
{
  assert(i==0);
  return Type_Face::segment_2D;
}
 
 
using Triangle = Triangle_32_64<int>;
using Triangle_64 = Triangle_32_64<trustIdType>;
 
#endif