bgeot_convex_structure.h

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/* -*- c++ -*- (enables emacs c++ mode) */
/*===========================================================================
 
 Copyright (C) 1999-2026 Yves Renard
 
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#ifndef BGEOT_CONVEX_STRUCTURE_H__
#define BGEOT_CONVEX_STRUCTURE_H__
 
/** @file bgeot_convex_structure.h
    @author  Yves Renard <[email protected]>
    @date December 20, 1999.
    @brief Definition of convex structures
 */
 
#include "gmm/gmm_ref.h"
#include "bgeot_config.h"
#include "bgeot_tensor.h"
#include "bgeot_poly.h"
#include "dal_static_stored_objects.h"
 
namespace bgeot {
  /** @defgroup convex_structure Convex Structure */
  /*@{*/
 
  // The number of faces for a convex is limited in certain applications
#  define MAX_FACES_PER_CV 31
 
  class convex_structure;
 
  /// Pointer on a convex structure description.
  typedef std::shared_ptr<const convex_structure> pconvex_structure;
 
  typedef std::vector<pconvex_structure> convex_structure_faces_ct;
  typedef std::vector<short_type>               convex_ind_ct;
  typedef gmm::tab_ref_index_ref< convex_ind_ct::const_iterator,
                 convex_ind_ct::const_iterator> ref_convex_ind_ct;
 
  /**  Structure of a convex.
   *
   * This class is not to be manipulated by itself. Use
   * pconvex_structure and the functions written to produce the
   * convex structures from classicals convexes (simplexes, polygonals
   * ...). The reason is that there is no need for having more than
   * one convex structure for the same type of convex.
   */
  class convex_structure : virtual public dal::static_stored_object {
  protected :
 
    dim_type Nc;
    short_type nbpt, nbf;
    convex_structure_faces_ct  faces_struct;
    std::vector<convex_ind_ct> faces;
    convex_ind_ct              dir_points_;
    pconvex_structure basic_pcvs;
    bool auto_basic;
 
    pconvex_structure prod_a, prod_b; /* only filled for convex structures */
                                      /* product.                          */
 
    mutable std::map<std::vector<short_type>, convex_ind_ct> intersection_points;
 
  public :
 
    /// Number of faces.
    inline short_type nb_faces()  const { return nbf;  }
    /// Dimension of the convex.
    inline dim_type  dim()        const { return Nc;   }
    /// Number of vertices.
    inline short_type nb_points() const { return nbpt; }
    /** Number of vertices of a face.
     *  @param i the face number.
     */
    inline short_type nb_points_of_face(short_type i) const
    { return short_type(faces[i].size()); }
    /** Give an array of the indexes of the vertices of a face.
     *  The indexes are "local" to the convex.
     *  @param i the face number.
     */
    inline const convex_ind_ct &ind_points_of_face(short_type i) const
    { return faces[i]; }
    /** Give an array of the indexes of the vertices at the intersection
     *  of a set of faces. The indexes are "local" to the convex.
     *  @param i the face number.
     */
    const convex_ind_ct &
    ind_common_points_of_faces(const std::vector<short_type> &ftab) const;
    /** Return "direct" points indexes. These are the subset of points that
     *  can be used to build a direct vector basis. (rarely used)
     */
    inline const convex_ind_ct &ind_dir_points() const
    { return dir_points_; }
    /** Give a pointer array on the structures of the faces.
     *   faces_structure()[i] is a pointer on the structure of the face i.
     */
    inline const convex_structure_faces_ct &faces_structure() const
    { return faces_struct; }
    /** Return "direct" points indexes for a given face.
     *  @param i the face number.
     */
    inline ref_convex_ind_ct ind_dir_points_of_face(short_type i) const {
      return ref_convex_ind_ct(faces[i].begin(),
                               faces_struct[i]->ind_dir_points().begin(),
                               faces_struct[i]->ind_dir_points().end());
    }
 
    void init_for_adaptative(pconvex_structure cvs);
    void add_point_adaptative(short_type i, short_type f);
    /** Return true if the convex structure is indeed a direct product
     *  of two convex structures.
     *  @param pprod1 the first sub-structure (optional)
     *  @param pprod2 the second sub-structure (optional)
     */
    bool is_product(pconvex_structure *pprod1=0,
                    pconvex_structure *pprod2=0) const {
      if (pprod1) *pprod1 = prod_a;
      if (pprod2) *pprod2 = prod_b;
      return prod_a ? true : false;
    }
    explicit convex_structure(bool auto_b)
      : auto_basic(auto_b), prod_a(0), prod_b(0)
    { DAL_STORED_OBJECT_DEBUG_CREATED(this, "Convex structure"); }
    virtual ~convex_structure()
    { DAL_STORED_OBJECT_DEBUG_DESTROYED(this, "Convex structure"); }
  protected:
    convex_structure() : auto_basic(false), prod_a(0), prod_b(0)
    { DAL_STORED_OBJECT_DEBUG_CREATED(this, "Convex structure"); }
    friend std::shared_ptr<convex_structure> new_convex_structure();
    friend pconvex_structure basic_structure(pconvex_structure cv);
  };
 
  /**
  *   Stored objects must be compared by keys, because there is a possibility that
  *   they are duplicated in storages of multiple threads and pointers to them are
  *   never equal
  */
  bool operator==(const pconvex_structure &p1, const pconvex_structure &p2);
  bool operator!=(const pconvex_structure &p1, const pconvex_structure &p2);
 
  //!these operators still use comparison by addresses against nullptr
  bool operator==(const pconvex_structure &p1, std::nullptr_t);
  bool operator==(std::nullptr_t, const pconvex_structure &p2);
  bool operator!=(const pconvex_structure &p1, std::nullptr_t);
  bool operator!=(std::nullptr_t, const pconvex_structure &p2);
 
  /// Original structure (if concerned)
  inline pconvex_structure basic_structure(pconvex_structure cv)
  { if (cv->auto_basic) return cv; else return cv->basic_pcvs; }
 
  inline std::shared_ptr<convex_structure> new_convex_structure()
  { return std::make_shared<convex_structure>(false); }
 
  /** @name functions on convex structures
   */
  //@{
 
  /** Print the details of the convex structure cvs to the output stream o.
   *   For debuging purpose.
   */
  std::ostream &operator << (std::ostream &o,
                             const convex_structure &cv);
 
  /// Give a pointer on the structures of a simplex of dimension d.
  pconvex_structure simplex_structure(dim_type d);
  /// Give a pointer on the structures of a parallelepiped of dimension d.
  pconvex_structure parallelepiped_structure(dim_type d, dim_type k = 1);
  /// Give a pointer on the structures of a polygon with n vertex.
  pconvex_structure polygon_structure(short_type);
  /** Give a pointer on the structures of a incomplete Q2
      quadrilateral/hexahedral of dimension d = 2 or 3.
  */
  pconvex_structure Q2_incomplete_structure(dim_type d);
  /** Give a pointer on the structures of a convex which is the direct
   *   product of the convexes represented by *pcvs1 and *pcvs2.
   */
  pconvex_structure convex_product_structure(pconvex_structure,
                                             pconvex_structure);
  /** Give a pointer on the structures of a prism of dimension d.
   *   i.e. the direct product of a simplex of dimension d-1 and a segment.
   */
  inline pconvex_structure prism_P1_structure(dim_type nc) {
    return convex_product_structure(simplex_structure(dim_type(nc-1)),
                                    simplex_structure(1));
  }
  /// Give a pointer on the 3D quadratic incomplete prism structure.
  pconvex_structure prism_incomplete_P2_structure();
  /// Give a pointer on the 3D pyramid structure for a degree k = 1 or 2.
  pconvex_structure pyramid_QK_structure(short_type k);
  /// Give a pointer on the 3D quadratic incomplete pyramid structure.
  pconvex_structure pyramid_Q2_incomplete_structure();
 
  IS_DEPRECATED inline pconvex_structure
  prism_structure(dim_type nc) { return prism_P1_structure(nc); }
  IS_DEPRECATED inline pconvex_structure
  pyramid_structure(short_type k) { return pyramid_QK_structure(k); }
 
 
  /** Simplex structure with the Lagrange grid of degree k.
      @param n the simplex dimension.
      @param k the simplex degree.
  */
  pconvex_structure simplex_structure(dim_type n, short_type k);
 
  /// Generic convex with n global nodes
  pconvex_structure generic_dummy_structure(dim_type nc, size_type n,
                                            short_type nf);
 
  //@}
 
  /*@}*/
}  /* end of namespace bgeot.                                             */
 
 
#endif /* BGEOT_CONVEX_STRUCTURE_H__                                      */