libigl_Martin/include/igl/cgal/outer_element.h

// This file is part of libigl, a simple c++ geometry processing library.
// 
// Copyright (C) 2015 Qingan Zhou <qnzhou@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_OUTER_ELEMENT_H
#define IGL_CGAL_OUTER_ELEMENT_H
#include "../igl_inline.h"
#include <Eigen/Core>
namespace igl
{
  namespace cgal
  {
    // Find a vertex that is reachable from infinite without crossing any faces.
    // Such vertex is called "outer vertex."
    //
    // Precondition: The input mesh must have all self-intersection resolved and
    // no duplicated vertices.  See cgal::remesh_self_intersections.h for how to
    // obtain such input.
    //
    // Inputs:
    //   V  #V by 3 list of vertex positions
    //   F  #F by 3 list of triangle indices into V
    //   I  #I list of facets to consider
    // Outputs:
    //   v_index  index of outer vertex
    //   A  #A list of facets incident to the outer vertex
    template <
        typename DerivedV,
        typename DerivedF,
        typename DerivedI,
        typename IndexType,
        typename DerivedA
        >
    IGL_INLINE void outer_vertex(
            const Eigen::PlainObjectBase<DerivedV> & V,
            const Eigen::PlainObjectBase<DerivedF> & F,
            const Eigen::PlainObjectBase<DerivedI> & I,
            IndexType & v_index,
            Eigen::PlainObjectBase<DerivedA> & A);
    // Find an edge that is reachable from infinity without crossing any faces.
    // Such edge is called "outer edge."
    //
    // Precondition: The input mesh must have all self-intersection resolved
    // and no duplicated vertices.  The correctness of the output depends on
    // the fact that there is no edge overlap.  See
    // cgal::remesh_self_intersections.h for how to obtain such input.
    //
    // Inputs:
    //   V  #V by 3 list of vertex positions
    //   F  #F by 3 list of triangle indices into V
    //   I  #I list of facets to consider
    // Outputs:
    //   v1 index of the first end point of outer edge
    //   v2 index of the second end point of outer edge
    //   A  #A list of facets incident to the outer edge
    template<
        typename DerivedV,
        typename DerivedF,
        typename DerivedI,
        typename IndexType,
        typename DerivedA
        >
    IGL_INLINE void outer_edge(
            const Eigen::PlainObjectBase<DerivedV> & V,
            const Eigen::PlainObjectBase<DerivedF> & F,
            const Eigen::PlainObjectBase<DerivedI> & I,
            IndexType & v1,
            IndexType & v2,
            Eigen::PlainObjectBase<DerivedA> & A);


    // Find a facet that is reachable from infinity without crossing any faces.
    // Such facet is called "outer facet."
    //
    // Precondition: The input mesh must have all self-intersection resolved.
    // I.e there is no duplicated vertices, no overlapping edge and no
    // intersecting faces (the only exception is there could be topologically
    // duplicated faces).  See cgal::remesh_self_intersections.h for how to
    // obtain such input.
    //
    // Inputs:
    //   V  #V by 3 list of vertex positions
    //   F  #F by 3 list of triangle indices into V
    //   N  #N by 3 list of face normals
    //   I  #I list of facets to consider
    // Outputs:
    //   f  Index of the outer facet.
    //   flipped  true iff the normal of f points inwards.
    template<
        typename DerivedV,
        typename DerivedF,
        typename DerivedN,
        typename DerivedI,
        typename IndexType
        >
    IGL_INLINE void outer_facet(
            const Eigen::PlainObjectBase<DerivedV> & V,
            const Eigen::PlainObjectBase<DerivedF> & F,
            const Eigen::PlainObjectBase<DerivedN> & N,
            const Eigen::PlainObjectBase<DerivedI> & I,
            IndexType & f,
            bool & flipped);
  }
}

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