BambuStudio/libigl/igl/copyleft/cgal/resolve_intersections.cpp

91 lines
2.7 KiB
C++

// This file is part of libigl, a simple c++ geometry processing library.
//
// Copyright (C) 2016 Alec Jacobson <alecjacobson@gmail.com>
//
// This Source Code Form is subject to the terms of the Mozilla Public License
// v. 2.0. If a copy of the MPL was not distributed with this file, You can
// obtain one at http://mozilla.org/MPL/2.0/.
#include "resolve_intersections.h"
#include "subdivide_segments.h"
#include "row_to_point.h"
#include "../../unique.h"
#include "../../list_to_matrix.h"
#include <CGAL/Exact_predicates_exact_constructions_kernel.h>
#include <CGAL/Segment_2.h>
#include <CGAL/Point_2.h>
#include <algorithm>
#include <vector>
template <
typename DerivedV,
typename DerivedE,
typename DerivedVI,
typename DerivedEI,
typename DerivedJ,
typename DerivedIM>
IGL_INLINE void igl::copyleft::cgal::resolve_intersections(
const Eigen::PlainObjectBase<DerivedV> & V,
const Eigen::PlainObjectBase<DerivedE> & E,
Eigen::PlainObjectBase<DerivedVI> & VI,
Eigen::PlainObjectBase<DerivedEI> & EI,
Eigen::PlainObjectBase<DerivedJ> & J,
Eigen::PlainObjectBase<DerivedIM> & IM)
{
using namespace Eigen;
using namespace igl;
using namespace std;
// Exact scalar type
typedef CGAL::Epeck K;
typedef K::FT EScalar;
typedef CGAL::Segment_2<K> Segment_2;
typedef CGAL::Point_2<K> Point_2;
typedef Matrix<EScalar,Dynamic,Dynamic> MatrixXE;
// Convert vertex positions to exact kernel
MatrixXE VE(V.rows(),V.cols());
for(int i = 0;i<V.rows();i++)
{
for(int j = 0;j<V.cols();j++)
{
VE(i,j) = V(i,j);
}
}
const int m = E.rows();
// resolve all intersections: silly O(n²) implementation
std::vector<std::vector<Point_2> > steiner(m);
for(int i = 0;i<m;i++)
{
Segment_2 si(row_to_point<K>(VE,E(i,0)),row_to_point<K>(VE,E(i,1)));
steiner[i].push_back(si.vertex(0));
steiner[i].push_back(si.vertex(1));
for(int j = i+1;j<m;j++)
{
Segment_2 sj(row_to_point<K>(VE,E(j,0)),row_to_point<K>(VE,E(j,1)));
// do they intersect?
if(CGAL::do_intersect(si,sj))
{
CGAL::Object result = CGAL::intersection(si,sj);
if(const Point_2 * p = CGAL::object_cast<Point_2 >(&result))
{
steiner[i].push_back(*p);
steiner[j].push_back(*p);
// add intersection point
}else if(const Segment_2 * s = CGAL::object_cast<Segment_2 >(&result))
{
// add both endpoints
steiner[i].push_back(s->vertex(0));
steiner[j].push_back(s->vertex(0));
steiner[i].push_back(s->vertex(1));
steiner[j].push_back(s->vertex(1));
}else
{
assert(false && "Unknown intersection type");
}
}
}
}
subdivide_segments(V,E,steiner,VI,EI,J,IM);
}