libigl_Martin/include/igl/cgal/remesh_self_intersections.h

// This file is part of libigl, a simple c++ geometry processing library.
// 
// Copyright (C) 2014 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_CGAL_REMESH_SELF_INTERSECTIONS_H
#define IGL_CGAL_REMESH_SELF_INTERSECTIONS_H
#include <igl/igl_inline.h>
#include "RemeshSelfIntersectionsParam.h"

#include <Eigen/Dense>

#ifdef MEX
#  include <mex.h>
#  include <cassert>
#  undef assert
#  define assert( isOK ) ( (isOK) ? (void)0 : (void) mexErrMsgTxt(C_STR(__FILE__<<":"<<__LINE__<<": failed assertion `"<<#isOK<<"'"<<std::endl) ) )
#endif
  
namespace igl
{
  namespace cgal
  {
    // Given a triangle mesh (V,F) compute a new mesh (VV,FF) which is the same
    // as (V,F) except that any self-intersecting triangles in (V,F) have been
    // subdivided (new vertices and face created) so that the self-intersection
    // contour lies exactly on edges in (VV,FF). New vertices will appear in
    // original faces or on original edges. New vertices on edges are "merged"
    // only across original faces sharing that edge. This means that if the input
    // triangle mesh is a closed manifold the output will be too.
    //
    // Inputs:
    //   V  #V by 3 list of vertex positions
    //   F  #F by 3 list of triangle indices into V
    //   params  struct of optional parameters
    // Outputs:
    //   VV  #VV by 3 list of vertex positions
    //   FF  #FF by 3 list of triangle indices into VV
    //   IF  #intersecting face pairs by 2  list of intersecting face pairs,
    //     indexing F
    //   J  #FF list of indices into F denoting birth triangle
    //   IM  #VV list of indices into VV of unique vertices.
    //
    // Known bugs: If an existing edge in (V,F) lies exactly on another face then
    // any resulting additional vertices along that edge may not get properly
    // connected so that the output mesh has the same global topology. This is
    // because 
    //
    // Example:
    //     // resolve intersections
    //     igl::cgal::remesh_self_intersections(V,F,params,VV,FF,IF,J,IM);
    //     // _apply_ duplicate vertex mapping IM to FF
    //     for_each(FF.data(),FF.data()+FF.size(),[&IM](int & a){a=IM(a);});
    //     // remove any vertices now unreferenced after duplicate mapping.
    //     igl::remove_unreferenced(VV,FF,SV,SF,UIM);
    //     // Now (SV,SF) is ready to extract outer hull
    //     igl::cgal::outer_hull(SV,SF,G,J,flip);
    //
    template <
      typename DerivedV,
      typename DerivedF,
      typename DerivedVV,
      typename DerivedFF,
      typename DerivedIF,
      typename DerivedJ,
      typename DerivedIM>
    IGL_INLINE void remesh_self_intersections(
      const Eigen::PlainObjectBase<DerivedV> & V,
      const Eigen::PlainObjectBase<DerivedF> & F,
      const RemeshSelfIntersectionsParam & params,
      Eigen::PlainObjectBase<DerivedVV> & VV,
      Eigen::PlainObjectBase<DerivedFF> & FF,
      Eigen::PlainObjectBase<DerivedIF> & IF,
      Eigen::PlainObjectBase<DerivedJ> & J,
      Eigen::PlainObjectBase<DerivedIM> & IM);
  }
}

#ifndef IGL_STATIC_LIBRARY
#  include "remesh_self_intersections.cpp"
#endif
  
#endif