dust3d/third_party/libigl/include/igl/faces_first.h

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// This file is part of libigl, a simple c++ geometry processing library.
//
// Copyright (C) 2013 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_FACES_FIRST_H
#define IGL_FACES_FIRST_H
#include "igl_inline.h"
namespace igl
{
// FACES_FIRST Reorder vertices so that vertices in face list come before
// vertices that don't appear in the face list. This is especially useful if
// the face list contains only surface faces and you want surface vertices
// listed before internal vertices
//
// [RV,RT,RF,IM] = faces_first(V,T,F);
//
// Templates:
// MatV matrix for vertex positions, e.g. MatrixXd
// MatF matrix for face indices, e.g. MatrixXi
// VecI vector for index map, e.g. VectorXi
// Input:
// V # vertices by 3 vertex positions
// F # faces by 3 list of face indices
// Output:
// RV # vertices by 3 vertex positions, order such that if the jth vertex is
// some face in F, and the kth vertex is not then j comes before k
// RF # faces by 3 list of face indices, reindexed to use RV
// IM #V by 1 list of indices such that: RF = IM(F) and RT = IM(T)
// and RV(IM,:) = V
//
//
// Example:
// // Tet mesh in (V,T,F)
// faces_first(V,F,IM);
// T = T.unaryExpr(bind1st(mem_fun( static_cast<VectorXi::Scalar&
// (VectorXi::*)(VectorXi::Index)>(&VectorXi::operator())),
// &IM)).eval();
template <typename MatV, typename MatF, typename VecI>
IGL_INLINE void faces_first(
const MatV & V,
const MatF & F,
MatV & RV,
MatF & RF,
VecI & IM);
// Virtual "in place" wrapper
template <typename MatV, typename MatF, typename VecI>
IGL_INLINE void faces_first(
MatV & V,
MatF & F,
VecI & IM);
}
#ifndef IGL_STATIC_LIBRARY
# include "faces_first.cpp"
#endif
#endif