halfedgeds_items_decorator.h

很多二维 三维几何计算算法 C++ 类库

// Copyright (c) 1997  Max-Planck-Institute Saarbruecken (Germany).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org); you may redistribute it under
// the terms of the Q Public License version 1.0.
// See the file LICENSE.QPL distributed with CGAL.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL: svn+ssh://scm.gforge.inria.fr/svn/cgal/branches/CGAL-3.3-branch/Nef_2/include/CGAL/Nef_2/HalfedgeDS_items_decorator.h $
// $Id: HalfedgeDS_items_decorator.h 28567 2006-02-16 14:30:13Z lsaboret $
// 
//
// Author(s)     : Lutz Kettner  <[e-mail]>

#ifndef CGAL_HALFEDGEDS_ITEMS_DECORATOR_H
#define CGAL_HALFEDGEDS_ITEMS_DECORATOR_H 1

#include <CGAL/basic.h>

CGAL_BEGIN_NAMESPACE

template < class p_HDS >
class HalfedgeDS_items_decorator {
public:

// TYPES
// ----------------------------------
    typedef p_HDS                                 HDS;
    typedef p_HDS                                 HalfedgeDS;
    typedef typename HDS::Traits                  Traits;
    typedef typename HDS::Vertex                  Vertex;
    typedef typename HDS::Halfedge                Halfedge;
    typedef typename HDS::Face                    Face;

    typedef typename HDS::Vertex_handle           Vertex_handle;
    typedef typename HDS::Vertex_const_handle     Vertex_const_handle;
    typedef typename HDS::Vertex_iterator         Vertex_iterator;
    typedef typename HDS::Vertex_const_iterator   Vertex_const_iterator;

    typedef typename HDS::Halfedge_handle         Halfedge_handle;
    typedef typename HDS::Halfedge_const_handle   Halfedge_const_handle;
    typedef typename HDS::Halfedge_iterator       Halfedge_iterator;
    typedef typename HDS::Halfedge_const_iterator Halfedge_const_iterator;

    typedef typename HDS::Face_handle             Face_handle;
    typedef typename HDS::Face_const_handle       Face_const_handle;
    typedef typename HDS::Face_iterator           Face_iterator;
    typedef typename HDS::Face_const_iterator     Face_const_iterator;

    typedef typename HDS::size_type               size_type;
    typedef typename HDS::difference_type         difference_type;
    typedef typename HDS::iterator_category       iterator_category;

// The following types are equal to either `Tag_true' or `Tag_false',
// dependent whether the named feature is supported or not.

    typedef typename HDS::Supports_vertex_halfedge
                                                  Supports_vertex_halfedge;
    typedef typename HDS::Supports_halfedge_prev  Supports_halfedge_prev;
    typedef typename HDS::Supports_halfedge_vertex
                                                  Supports_halfedge_vertex;
    typedef typename HDS::Supports_halfedge_face  Supports_halfedge_face;
    typedef typename HDS::Supports_face_halfedge  Supports_face_halfedge;

    typedef typename HDS::Supports_removal        Supports_removal;

protected:
    typedef typename Vertex::Base                 VBase;
    typedef typename Halfedge::Base               HBase;
    typedef typename Halfedge::Base_base          HBase_base;
    typedef typename Face::Base                   FBase;

public:

// CREATION
// ----------------------------------

    HalfedgeDS_items_decorator() {}

// Access Functions
// ----------------------------------

    Halfedge_handle get_vertex_halfedge( Vertex_handle v) const {
        // returns the incident halfedge of v if supported,
        // `Halfedge_handle()' otherwise.
        return get_vertex_halfedge( v, Supports_vertex_halfedge());
    }

    Vertex_handle get_vertex( Halfedge_handle h) const {
        // returns the incident vertex of h if supported,
        // `Vertex_handle()' otherwise.
        return get_vertex( h, Supports_halfedge_vertex());
    }

    Halfedge_handle get_prev( Halfedge_handle h) const {
        // returns the previous halfedge of h if supported,
        // `Halfedge_handle()' otherwise.
        return get_prev( h, Supports_halfedge_prev());
    }

    Halfedge_handle find_prev( Halfedge_handle h) const {
        // returns the previous halfedge of h. Uses the `prev()' method if
        // supported or performs a search around the face using `next()'.
        return find_prev( h, Supports_halfedge_prev());
    }

    Halfedge_handle find_prev_around_vertex( Halfedge_handle h) const {
        // returns the previous halfedge of h. Uses the `prev()' method if
        // supported or performs a search around the vertex using `next()'.
        return find_prev_around_vertex( h, Supports_halfedge_prev());
    }

    Face_handle get_face( Halfedge_handle h) const {
        // returns the incident face of h if supported,
        // `Face_handle()' otherwise.
        return get_face( h, Supports_halfedge_face());
    }

    Halfedge_handle get_face_halfedge( Face_handle f) const {
        // returns the incident halfedge of f if supported,
        // `Halfedge_handle()' otherwise.
        return get_face_halfedge( f, Supports_face_halfedge());
    }

// Const Access Functions
// ----------------------------------

    Halfedge_const_handle
    get_vertex_halfedge( Vertex_const_handle v) const {
        return get_vertex_halfedge( v, Supports_vertex_halfedge());
    }

    Vertex_const_handle get_vertex( Halfedge_const_handle h) const {
        return get_vertex( h, Supports_halfedge_vertex());
    }

    Halfedge_const_handle get_prev( Halfedge_const_handle h) const {
        return get_prev( h, Supports_halfedge_prev());
    }

    Halfedge_const_handle find_prev( Halfedge_const_handle h) const {
        return find_prev( h, Supports_halfedge_prev());
    }

    Halfedge_const_handle
    find_prev_around_vertex( Halfedge_const_handle h) const {
        return find_prev_around_vertex( h, Supports_halfedge_prev());
    }

    Face_const_handle get_face( Halfedge_const_handle h) const {
        return get_face( h, Supports_halfedge_face());
    }

    Halfedge_const_handle get_face_halfedge( Face_const_handle f) const {
        return get_face_halfedge( f, Supports_face_halfedge());
    }

// Modifying Functions (Primitives)
// ----------------------------------

    void set_vertex_halfedge( Vertex_handle v, Halfedge_handle g) const {
        // sets the incident halfedge of v to g.
        set_vertex_halfedge( v, g, Supports_vertex_halfedge());
    }

    void set_vertex_halfedge( Halfedge_handle h) const {
        // sets the incident halfedge of the vertex incident to h to h.
        set_vertex_halfedge( h, h, Supports_halfedge_vertex());
    }

    void set_vertex( Halfedge_handle h, Vertex_handle v) const {
        // sets the incident vertex of h to v.
        set_vertex(h, v, Supports_halfedge_vertex());
    }

    void set_prev( Halfedge_handle h, Halfedge_handle g) const {
        // sets the previous link of h to g.
        set_prev( h, g, Supports_halfedge_prev());
    }

    void set_face( Halfedge_handle h, Face_handle f) const {
        // sets the incident face of h to f.
        set_face(h, f, Supports_halfedge_face());
    }

    void set_face_halfedge( Face_handle f, Halfedge_handle g) const {
        // sets the incident halfedge of f to g.
        set_face_halfedge( f, g, Supports_face_halfedge());
    }

    void set_face_halfedge( Halfedge_handle h) const {
        // sets the incident halfedge of the face incident to h to h.
        set_face_halfedge( h, h, Supports_halfedge_face());
    }

// Modifying Functions (Composed)
// ----------------------------------

    void close_tip( Halfedge_handle h) const {
        // makes `h->opposite()' the successor of h.
        h->HBase::set_next( h->opposite());
        set_prev( h->opposite(), h);
    }

    void close_tip( Halfedge_handle h, Vertex_handle v) const {
        // makes `h->opposite()' the successor of h and sets the incident
        // vertex of h to v.
        h->HBase::set_next( h->opposite());
        set_prev( h->opposite(), h);
        set_vertex( h, v);
    }

    void insert_tip( Halfedge_handle h, Halfedge_handle v) const {
        // inserts the tip of the edge h into the halfedges around the
        // vertex pointed to by v. Halfedge `h->opposite()' is the new
        // successor of v and `h->next()' will be set to `v->next()'. The
        // vertex of h will be set to the vertex v refers to if vertices
        // are supported.
        h->HBase::set_next( v->next());
        v->HBase::set_next( h->opposite());
        set_prev( h->next(), h);
        set_prev( h->opposite(), v);
        set_vertex( h, get_vertex( v));
    }

    void remove_tip( Halfedge_handle h) const {
        // removes the edge `h->next()->opposite()' from the halfedge
        // circle around the vertex referred to by h. The new successor
        // halfedge of h will be `h->next()->opposite()->next()'.
        h->HBase::set_next( h->next()->opposite()->next());
        set_prev( h->next(), h);
    }

    void insert_halfedge( Halfedge_handle h, Halfedge_handle f) const {
        // inserts the halfedge h between f and `f->next()'. The face of h
        // will be the one f refers to if faces are supported.
        h->HBase::set_next( f->next());
        f->HBase::set_next( h);
        set_prev( h->next(), h);
        set_prev( h, f);
        set_face( h, get_face( f));
    }

    void remove_halfedge( Halfedge_handle h) const {
        // removes edge `h->next()' from the halfedge circle around the
        // face referred to by h. The new successor of h will be
        // `h->next()->next()'.
        h->HBase::set_next( h->next()->next());
        set_prev( h->next(), h);
    }

    void set_vertex_in_vertex_loop( Halfedge_handle h, Vertex_handle v,
                                    CGAL::Tag_false) const {}
    void set_vertex_in_vertex_loop( Halfedge_handle h, Vertex_handle v,
                                    CGAL::Tag_true) const {
        CGAL_assertion_code( size_t termination_count = 0;)
        Halfedge_handle end = h;
        do {
            CGAL_assertion( ++termination_count != 0);
            h->HBase::set_vertex( v);
            h = h->next()->opposite();
        } while ( h != end);
    }