// This file is part of libigl, a simple c++ geometry processing library.
// 
// Copyright (C) 2020 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_TETRAHEDRALIZED_GRID_H
#define IGL_TETRAHEDRALIZED_GRID_H
#include "igl_inline.h"
#include <Eigen/Core>
namespace igl
{
  /// Types of tetrahedralizations of a cubical cell
  enum TetrahedralizedGripType
  {
    /// 1 cube → 5 tets
    TETRAHEDRALIZED_GRID_TYPE_5 = 0,
    /// 1 cube → 6 tets with rotatonal symmetry
    TETRAHEDRALIZED_GRID_TYPE_6_ROTATIONAL = 1,
    /// Total number of tetrahedralization types
    NUM_TETRAHEDRALIZED_GRID_TYPE = 2
  };
  /// Construct vertices of a regular grid, suitable for input to
  /// `igl::marching_tets`
  ///
  /// @param[in] nx  number of grid vertices in x direction
  /// @param[in] ny  number of grid vertices in y direction
  /// @param[in] nz  number of grid vertices in z direction
  /// @param[in] type  type of tetrahedralization of cube to use
  /// @param[out] GV  nx*ny*nz by 3 list of grid vertex positions
  /// @param[out] GT  (nx-1)*(ny-1)*(nz-1)*k by 4 list of tetrahedron indices into rows of
  ///     V, where k is the number of tets per cube (dependent on type)
  ///
  /// \see triangulated_grid, quad_grid
  template <
    typename DerivedGV,
    typename DerivedGT>
  IGL_INLINE void tetrahedralized_grid(
    const int nx,
    const int ny,
    const int nz,
    const TetrahedralizedGripType type,
    Eigen::PlainObjectBase<DerivedGV> & GV,
    Eigen::PlainObjectBase<DerivedGT> & GT);
  /// \overload
  /// @param[in] side  3-long list {nx,ny,nz} see above
  template <
    typename Derivedside,
    typename DerivedGT>
  IGL_INLINE void tetrahedralized_grid(
    const Eigen::MatrixBase<Derivedside> & side,
    const TetrahedralizedGripType type,
    Eigen::PlainObjectBase<DerivedGT> & GT);
}
#ifndef IGL_STATIC_LIBRARY
#  include "tetrahedralized_grid.cpp"
#endif
#endif