/* -*- c++ -*- (enables emacs c++ mode) */
/*===========================================================================
 
 Copyright (C) 1999-2012 Yves Renard
 
 This file is a part of GETFEM++
 
 Getfem++  is  free software;  you  can  redistribute  it  and/or modify it
 under  the  terms  of the  GNU  Lesser General Public License as published
 by  the  Free Software Foundation;  either version 3 of the License,  or
 (at your option) any later version along with the GCC Runtime Library
 Exception either version 3.1 or (at your option) any later version.
 This program  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 Lesser General Public
 License and GCC Runtime Library Exception for more details.
 You  should  have received a copy of the GNU Lesser General Public License
 along  with  this program;  if not, write to the Free Software Foundation,
 Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
 
 As a special exception, you  may use  this file  as it is a part of a free
 software  library  without  restriction.  Specifically,  if   other  files
 instantiate  templates  or  use macros or inline functions from this file,
 or  you compile this  file  and  link  it  with other files  to produce an
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 might be covered by the GNU Lesser General Public License.
 
===========================================================================*/

#ifndef BGEOT_CONVEX_STRUCTURE_H__
#define BGEOT_CONVEX_STRUCTURE_H__

/** @file bgeot_convex_structure.h
    @author  Yves Renard <Yves.Renard@insa-lyon.fr>
    @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 boost::intrusive_ptr<const convex_structure> pconvex_structure;

  typedef std::vector<const convex_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 manipulate 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_;
    const convex_structure *basic_pcvs;
    
    pconvex_structure prod_a, prod_b; /* only filled for convex structures */
				      /* product.                          */
    public :

      /// Number of faces.
      inline short_type nb_faces(void)  const { return nbf;  }
      /// Dimension of the convex.
      inline dim_type  dim(void)        const { return Nc;   }
      /// Number of vertices.
      inline short_type nb_points(void) const { return nbpt; }
      /// Original structure (if concerned).
      pconvex_structure basic_structure(void) const 
      { return basic_pcvs; }
    /** 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]; }
    /** 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(void) 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;
    }
  protected:
    convex_structure() { prod_a = prod_b = 0; }
    friend boost::intrusive_ptr<convex_structure> new_convex_structure();
  };

  inline boost::intrusive_ptr<convex_structure> new_convex_structure()
  { return boost::intrusive_ptr<convex_structure>(new convex_structure); }

  /** @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);
  /// 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 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_structure(dim_type nc) { 
    return convex_product_structure(simplex_structure(dim_type(nc-1)),
				    simplex_structure(1));
  }

  /** 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,
					    size_type nf);

  //@}

  /*@}*/
}  /* end of namespace bgeot.                                             */


#endif /* BGEOT_CONVEX_STRUCTURE_H__                                      */
