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// This file is part of libigl, a simple c++ geometry processing library.
//
// Copyright (C) 2015 Qingnan 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_COPYLEFT_CGAL_PROPAGATE_WINDING_NUMBERS_H
#define IGL_COPYLEFT_CGAL_PROPAGATE_WINDING_NUMBERS_H
#include "../../igl_inline.h"
#include <Eigen/Core>
#include <vector>
// The following methods compute the winding number on each side of each facet
// or patch of a 3D mesh. The input mesh is valid if it splits the ambient
// space, R^3, into subspaces with constant integer winding numbers. That is
// the input mesh should be closed and for each directed edge the number of
// clockwise facing facets should equal the number of counterclockwise facing
// facets.
namespace igl
{
namespace copyleft
{
namespace cgal
{
/// Compute winding number on each side of the face. The input mesh
/// could contain multiple connected components. The input mesh must
/// represent the boundary of a valid 3D volume, which means it is
/// closed, consistently oriented and induces integer winding numbers.
///
/// @param[in] V #V by 3 list of vertex positions.
/// @param[in] F #F by 3 list of triangle indices into V.
/// @param[in] labels #F list of facet labels ranging from 0 to k-1.
/// @param[out] W #F by k*2 list of winding numbers. ``W(i,j*2)`` is the winding
/// number on the positive side of facet ``i`` with respect to the
/// facets labeled ``j``. Similarly, ``W(i,j*2+1)`` is the winding
/// number on the negative side of facet ``i`` with respect to the
/// facets labeled ``j``.
/// @return true iff the input induces a piecewise-constant winding number
/// field.
///
/// \note This shouldn't need to be in igl::copyleft::cgal, it should
/// instead take as input an index of the ambient cell and the winding
/// number vector there.
template<
typename DerivedV,
typename DerivedF,
typename DerivedL,
typename DerivedW>
IGL_INLINE bool propagate_winding_numbers(
const Eigen::PlainObjectBase<DerivedV>& V,
const Eigen::PlainObjectBase<DerivedF>& F,
const Eigen::PlainObjectBase<DerivedL>& labels,
Eigen::PlainObjectBase<DerivedW>& W);
// \overload
//
// @param[in] uE #uE by 2 list of vertex_indices, represents undirected edges.
// @param[in] uEC #uE+1 list of cumsums of directed edges sharing each unique edge
// @param[in] uEE #E list of indices into E (see `igl::unique_edge_map`)
// @param[in] num_patches number of patches
// @param[in] P #F list of patch ids.
// @param[in] num_cells number of cells
// @param[in] C #P by 2 list of cell ids on each side of each patch.
template<
typename DerivedV,
typename DerivedF,
typename DeriveduE,
typename DeriveduEC,
typename DeriveduEE,
typename DerivedP,
typename DerivedC,
typename DerivedL,
typename DerivedW>
IGL_INLINE bool propagate_winding_numbers(
const Eigen::PlainObjectBase<DerivedV>& V,
const Eigen::PlainObjectBase<DerivedF>& F,
const Eigen::PlainObjectBase<DeriveduE>& uE,
const Eigen::PlainObjectBase<DeriveduEC>& uEC,
const Eigen::PlainObjectBase<DeriveduEE>& uEE,
const size_t num_patches,
const Eigen::PlainObjectBase<DerivedP>& P,
const size_t num_cells,
const Eigen::PlainObjectBase<DerivedC>& C,
const Eigen::PlainObjectBase<DerivedL>& labels,
Eigen::PlainObjectBase<DerivedW>& W);
}
}
}
#ifndef IGL_STATIC_LIBRARY
# include "propagate_winding_numbers.cpp"
#endif
#endif