text: // 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/.
  #ifndef IGL_COPYLEFT_CGAL_SUBDIVIDE_SEGMENTS_H
  #define IGL_COPYLEFT_CGAL_SUBDIVIDE_SEGMENTS_H
  #include "../../igl_inline.h"
  #include <Eigen/Core>
  #include <CGAL/Segment_2.h>
  #include <CGAL/Point_2.h>
  #include <vector>
  namespace igl
  {
    namespace copyleft
    {
      namespace cgal
      {
        // Insert steiner points to subdivide a given set of line segments
        // 
        // Inputs:
        //   V  #V by 2 list of vertex positions
        //   E  #E by 2 list of segment indices into V
        //   steiner  #E list of lists of unsorted steiner points (including
        //     endpoints) along the #E original segments
        // Outputs:
        //   VI  #VI by 2 list of output vertex positions, copies of V are always
        //     the first #V vertices
        //   EI  #EI by 2 list of segment indices into V, #EI ≥ #E
        //   J  #EI list of indices into E revealing "parent segments"
        //   IM  #VI list of indices into VV of unique vertices.
        template <
          typename DerivedV, 
          typename DerivedE,
          typename Kernel, 
          typename DerivedVI, 
          typename DerivedEI,
          typename DerivedJ,
          typename DerivedIM>
        IGL_INLINE void subdivide_segments(
          const Eigen::PlainObjectBase<DerivedV> & V,
          const Eigen::PlainObjectBase<DerivedE> & E,
          const std::vector<std::vector<CGAL::Point_2<Kernel> > > & steiner,
          Eigen::PlainObjectBase<DerivedVI> & VI,
          Eigen::PlainObjectBase<DerivedEI> & EI,
          Eigen::PlainObjectBase<DerivedJ> & J,
          Eigen::PlainObjectBase<DerivedIM> & IM);
      }
    }
  }
  #ifndef IGL_STATIC_LIBRARY
  #  include "subdivide_segments.cpp"
  #endif
  #endif
  