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cgal/Arrangement_on_surface_2/include/CGAL/Arr_overlay_2.h

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// Copyright (c) 2005,2006,2007,2008,2009,2010,2011 Tel-Aviv University (Israel).
// 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.
//
// Author(s) : Baruch Zukerman <baruchzu@post.tau.ac.il>
// Efi Fogel <efif@post.tau.ac.il>
#ifndef CGAL_ARR_OVERLAY_2_H
#define CGAL_ARR_OVERLAY_2_H
#include <CGAL/license/Arrangement_on_surface_2.h>
/*! \file
* Definition of the global Arr_overlay_2() function.
*/
#include <boost/optional/optional.hpp>
#include <CGAL/Arrangement_on_surface_2.h>
#include <CGAL/Surface_sweep_2.h>
#include <CGAL/Surface_sweep_2/Arr_default_overlay_traits_base.h>
#include <vector>
#include <boost/mpl/if.hpp>
#include <boost/mpl/or.hpp>
#include <boost/type_traits.hpp>
#include <CGAL/assertions.h>
namespace CGAL {
/*!
* Compute the overlay of two input arrangements.
* \param arr1 The first arrangement.
* \param arr2 The second arrangement.
* \param arr_res Output: The resulting arrangement.
* \param ovl_tr An overlay-traits class. As arr1, arr2 and res can be
* templated with different geometry-traits class and
* different DCELs (encapsulated in the various topology-traits
* classes). The geometry-traits of the result arrangement is
* used to construct the result arrangement. This means that all
* the types (e.g., Point_2, Curve_2 and X_monotone_2) of both
* arr1 and arr2 have to be convertible to the types
* in the result geometry-traits.
* The overlay-traits class defines the various
* overlay operations of pairs of DCEL features from
* TopTraitsA and TopTraitsB to the resulting ResDcel.
*/
template <class GeomTraitsA,
class GeomTraitsB,
class GeomTraitsRes,
class TopTraitsA,
class TopTraitsB,
class TopTraitsRes,
class OverlayTraits>
void overlay(const Arrangement_on_surface_2<GeomTraitsA, TopTraitsA>& arr1,
const Arrangement_on_surface_2<GeomTraitsB, TopTraitsB>& arr2,
Arrangement_on_surface_2<GeomTraitsRes, TopTraitsRes>& arr_res,
OverlayTraits& ovl_tr)
{
typedef Arrangement_on_surface_2<GeomTraitsA, TopTraitsA> ArrA;
typedef Arrangement_on_surface_2<GeomTraitsB, TopTraitsB> ArrB;
typedef Arrangement_on_surface_2<GeomTraitsRes, TopTraitsRes> ArrRes;
// some type assertions (not all, but better then nothing).
CGAL_static_assertion
((boost::is_convertible<typename GeomTraitsA::Point_2, \
typename GeomTraitsRes::Point_2>::value));
CGAL_static_assertion
((boost::is_convertible<typename GeomTraitsB::Point_2, \
typename GeomTraitsRes::Point_2 >::value));
CGAL_static_assertion
((boost::is_convertible<typename GeomTraitsA::X_monotone_curve_2, \
typename GeomTraitsRes::X_monotone_curve_2>::value));
CGAL_static_assertion
((boost::is_convertible<typename GeomTraitsB::X_monotone_curve_2, \
typename GeomTraitsRes::X_monotone_curve_2>::value));
typedef typename TopTraitsRes::template
Surface_sweep_overlay_visitor<ArrA, ArrB, OverlayTraits>
Ovl_visitor;
typedef typename Ovl_visitor::Traits_2 Ovl_traits_2;
typedef typename Ovl_traits_2::X_monotone_curve_2 Ovl_x_monotone_curve_2;
typedef typename Ovl_traits_2::Point_2 Ovl_point_2;
typedef typename Ovl_traits_2::Cell_handle_red Cell_handle_red;
typedef typename Ovl_traits_2::Optional_cell_red Optional_cell_red;
typedef typename Ovl_traits_2::Cell_handle_blue Cell_handle_blue;
typedef typename Ovl_traits_2::Optional_cell_blue Optional_cell_blue;
CGAL_USE_TYPE(Optional_cell_red);
CGAL_USE_TYPE(Optional_cell_blue);
// The result arrangement cannot be on of the input arrangements.
CGAL_precondition(((void *)(&arr_res) != (void *)(&arr1)) &&
((void *)(&arr_res) != (void *)(&arr2)));
// Prepare a vector of extended x-monotone curves that represent all edges
// in both input arrangements. Each curve is associated with a halfedge
// directed from right to left.
typename ArrA::Halfedge_const_handle invalid_he1;
typename ArrB::Halfedge_const_handle invalid_he2;
std::vector<Ovl_x_monotone_curve_2>
xcvs_vec(arr1.number_of_edges() + arr2.number_of_edges());
unsigned int i = 0;
typename ArrA::Edge_const_iterator eit1;
for (eit1 = arr1.edges_begin(); eit1 != arr1.edges_end(); ++eit1, ++i) {
typename ArrA::Halfedge_const_handle he1 = eit1;
if (he1->direction() != ARR_RIGHT_TO_LEFT) he1 = he1->twin();
xcvs_vec[i] = Ovl_x_monotone_curve_2(eit1->curve(), he1, invalid_he2);
}
typename ArrB::Edge_const_iterator eit2;
for (eit2 = arr2.edges_begin(); eit2 != arr2.edges_end(); ++eit2, ++i) {
typename ArrB::Halfedge_const_handle he2 = eit2;
if (he2->direction() != ARR_RIGHT_TO_LEFT) he2 = he2->twin();
xcvs_vec[i] = Ovl_x_monotone_curve_2(eit2->curve(), invalid_he1, he2);
}
// Obtain a extended traits-class object and define the sweep-line visitor.
const typename ArrRes::Traits_adaptor_2* traits_adaptor =
arr_res.traits_adaptor();
/* We would like to avoid copy construction of the geometry traits class.
* Copy construction is undesired, because it may results with data
* duplication or even data loss.
*
* If the type Ovl_traits_2 is the same as the type
* GeomTraits, use a reference to GeomTraits to avoid constructing a new one.
* Otherwise, instantiate a local variable of the former and provide
* the later as a single parameter to the constructor.
*
* Use the form 'A a(*b);' and not ''A a = b;' to handle the case where A has
* only an implicit constructor, (which takes *b as a parameter).
*/
typedef Arr_traits_basic_adaptor_2< GeomTraitsRes > Geom_traits_adaptor_2;
typename boost::mpl::if_<boost::is_same< Geom_traits_adaptor_2, Ovl_traits_2>,
const Ovl_traits_2&, Ovl_traits_2>::type
ex_traits(*traits_adaptor);
Ovl_visitor visitor(&arr1, &arr2, &arr_res, &ovl_tr);
Surface_sweep_2<Ovl_traits_2, Ovl_visitor,
typename Ovl_visitor::Subcurve, typename Ovl_visitor::Event>
sweep_line(&ex_traits, &visitor);
// In case both arrangement do not contain isolated vertices, go on and
// overlay them.
const std::size_t total_iso_verts =
arr1.number_of_isolated_vertices() + arr2.number_of_isolated_vertices();
if (total_iso_verts == 0) {
// Clear the result arrangement and perform the sweep to construct it.
arr_res.clear();
sweep_line.sweep(xcvs_vec.begin(), xcvs_vec.end());
xcvs_vec.clear();
return;
}
// Prepare a vector of extended points that represent all isolated vertices
// in both input arrangements.
std::vector<Ovl_point_2> pts_vec(total_iso_verts);
i = 0;
typename ArrA::Vertex_const_iterator vit1;
for (vit1 = arr1.vertices_begin(); vit1 != arr1.vertices_end(); ++vit1) {
if (vit1->is_isolated()) {
typename ArrA::Vertex_const_handle v1 = vit1;
pts_vec[i++] =
Ovl_point_2(vit1->point(), boost::make_optional(Cell_handle_red(v1)),
boost::optional<Cell_handle_blue>());
}
}
typename ArrB::Vertex_const_iterator vit2;
for (vit2 = arr2.vertices_begin(); vit2 != arr2.vertices_end(); ++vit2) {
if (vit2->is_isolated()) {
typename ArrB::Vertex_const_handle v2 = vit2;
pts_vec[i++] =
Ovl_point_2(vit2->point(), boost::optional<Cell_handle_red>(),
boost::make_optional(Cell_handle_blue(v2)));
}
}
// Clear the result arrangement and perform the sweep to construct it.
arr_res.clear();
sweep_line.sweep(xcvs_vec.begin(), xcvs_vec.end(),
pts_vec.begin(), pts_vec.end());
xcvs_vec.clear();
pts_vec.clear();
}
/*!
* Compute the (simple) overlay of two input arrangements.
* \param arr1 The first arrangement.
* \param arr2 The second arrangement.
* \param arr_res Output: The resulting arrangement.
*/
template <class GeomTraitsA,
class GeomTraitsB,
class GeomTraitsRes,
class TopTraitsA,
class TopTraitsB,
class TopTraitsRes>
void overlay(const Arrangement_on_surface_2<GeomTraitsA, TopTraitsA>& arr1,
const Arrangement_on_surface_2<GeomTraitsB, TopTraitsB>& arr2,
Arrangement_on_surface_2<GeomTraitsRes, TopTraitsRes>& arr_res)
{
typedef Arrangement_on_surface_2<GeomTraitsA, TopTraitsA> ArrA;
typedef Arrangement_on_surface_2<GeomTraitsA, TopTraitsB> ArrB;
typedef Arrangement_on_surface_2<GeomTraitsRes, TopTraitsRes> ArrRes;
_Arr_default_overlay_traits_base<ArrA, ArrB, ArrRes> ovl_traits;
overlay(arr1, arr2, arr_res, ovl_traits);
}
} //namespace CGAL
#endif
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