cgal/Nef_3/include/CGAL/Nef_3/Shell_constructor.h

130 lines
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C++

// Copyright (c) 2005 Max-Planck-Institute Saarbruecken (Germany).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org).
// You can redistribute it and/or modify it under the terms of the GNU
// General Public License as published by the Free Software Foundation,
// either version 3 of the License, or (at your option) any later version.
//
// 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.
//
// $URL$
// $Id$
//
//
// Author(s) : Peter Hachenberger <hachenberger@mpi-sb.mpg.de>
#ifndef CGAL_NEF_SHELL_CONSTRUCTOR_H
#define CGAL_NEF_SHELL_CONSTRUCTOR_H
namespace CGAL {
template<class Nef3, typename forward_iterator>
class Shell_constructor : public Modifier_base<typename Nef3::SNC_structure> {
typedef Nef3 Nef_polyhedron;
typedef typename Nef_polyhedron::SNC_structure SNC_structure;
typedef typename SNC_structure::SM_decorator SM_decorator;
typedef typename SNC_structure::Vertex_handle Vertex_handle;
typedef typename SNC_structure::SVertex_handle SVertex_handle;
typedef typename SNC_structure::SHalfedge_handle SHalfedge_handle;
typedef typename SNC_structure::SFace_handle SFace_handle;
typedef typename SNC_structure::Sphere_point Sphere_point;
typedef typename SNC_structure::Sphere_circle Sphere_circle;
typedef typename SNC_structure::Kernel Kernel;
typedef typename Kernel::Line_3 Line_3;
std::vector<Vertex_iterator> Vertex_of;
std::istream in;
bool SNC_io_parser<EW>::check_sep(const char* sep) const {
char c;
do in.get(c); while (isspace(c));
while (*sep != '\0') {
if (*sep != c) {
in.putback(c);
return false;
}
++sep; in.get(c);
}
in.putback(c);
return true;
}
void add_sedge(SNC_structure& snc, int prev, int cur, int next) {
Vertex_handle v = Vertex_of[cur];
Sphere_point sp1(Vertex_of[prev]->point());
Sphere_point sp2(Vertex_of[next]->point());
sp1 = normalized(sp1);
sp2 = normalized(sp2);
SVertex_iterator sv;
SVertex_handle sv1, sv2;
for(sv = v->svertices_begin(); sv != v->svertices_end(); ++sv)
if(sv->point() == sp1)
sv1 = sv;
else if(sv->point() == sp2)
sv2 = sv;
SM_decorator(&*v);
if(sv1 == SVertex_handle())
sv1 = SM.new_svertex(sp1);
if(sv2 == SVertex_handle())
sv2 = SM.new_svertex(sp2);
SHalfedge_handle se = SM.new_shalfedge_pair(sv1, sv2);
se->mark() = se->twin()->mark() = true;
}
Vertex_handle read_vertex(SNC_structure& snc) {
RT hx, hy, hz;
in >> hx >> hy >> hz;;
return v(snc.new_vertex(Point_3(hx,hy,hz,1),true));
}
void read_facet(SNC_structure& snc) {
int n, prev, cur, next, first, second;
in >> n;
CGAL_assertion(n > 2);
in >> first;
in >> second;
prev = first;
cur = second;
n-=2;
for(;n>0;--n) {
in >> next;
add_sedge(snc, prev, cur, next);
prev = cur;
cur = next;
}
add_sedge(snc, cur, next, first);
add_sedge(snc, next, first, second);
}
public:
Shell_constructor(std::istream& instr) :
in(instr) {}
void operator()(SNC_structure& snc) {
if (!check_sep("OFF"))
CGAL_error_msg("OFF header is missing!");
int nv, nf, x;
in >> nv;
in >> nf;
in >> x;
Vertex_of.reserve(vn);
for(x=0; x<nv; ++nv)
Vertex_of[nv] = read_vertex(snc);
for(x=0; x<vf; ++nf)
read_facet(snc);
}
};
} //namespace CGAL
#endif // CGAL_NEF_SHELL_CONSTRUCTOR_H