// This file is part of libigl, a simple c++ geometry processing library.
// 
// Copyright (C) 2015 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_PROGRESSIVE_HULLS_H
#define IGL_COPYLEFT_PROGRESSIVE_HULLS_H
#include "../igl_inline.h"
#include <Eigen/Core>

namespace igl
{
  namespace copyleft
  {
    // Assumes (V,F) is a closed manifold mesh 
    // Collapses edges until desired number of faces is achieved but ensures
    // that new vertices are placed outside all previous meshes as per
    // "progressive hulls" in "Silhouette clipping" [Sander et al. 2000].
    //
    // Inputs:
    //   V  #V by dim list of vertex positions
    //   F  #F by 3 list of face indices into V.
    //   max_m  desired number of output faces
    // Outputs:
    //   U  #U by dim list of output vertex posistions (can be same ref as V)
    //   G  #G by 3 list of output face indices into U (can be same ref as G)
    //   J  #G list of indices into F of birth faces
    // Returns true if m was reached (otherwise #G > m)
    IGL_INLINE bool progressive_hulls(
      const Eigen::MatrixXd & V,
      const Eigen::MatrixXi & F,
      const size_t max_m,
      Eigen::MatrixXd & U,
      Eigen::MatrixXi & G,
      Eigen::VectorXi & J);
  }
}
#ifndef IGL_STATIC_LIBRARY
#  include "progressive_hulls.cpp"
#endif
#endif