72 lines
1.7 KiB
C++
72 lines
1.7 KiB
C++
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// This file is part of libigl, a simple c++ geometry processing library.
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//
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// Copyright (C) 2015 Alec Jacobson <alecjacobson@gmail.com>
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//
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// This Source Code Form is subject to the terms of the Mozilla Public License
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// v. 2.0. If a copy of the MPL was not distributed with this file, You can
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// obtain one at http://mozilla.org/MPL/2.0/.
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#include "circulation.h"
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#include "list_to_matrix.h"
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IGL_INLINE std::vector<int> igl::circulation(
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const int e,
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const bool ccw,
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const Eigen::MatrixXi & F,
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const Eigen::MatrixXi & E,
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const Eigen::VectorXi & EMAP,
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const Eigen::MatrixXi & EF,
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const Eigen::MatrixXi & EI)
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{
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// prepare output
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std::vector<int> N;
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N.reserve(6);
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const int m = F.rows();
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const auto & step = [&](
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const int e,
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const int ff,
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int & ne,
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int & nf)
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{
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assert((EF(e,1) == ff || EF(e,0) == ff) && "e should touch ff");
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//const int fside = EF(e,1)==ff?1:0;
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const int nside = EF(e,0)==ff?1:0;
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const int nv = EI(e,nside);
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// get next face
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nf = EF(e,nside);
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// get next edge
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const int dir = ccw?-1:1;
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ne = EMAP(nf+m*((nv+dir+3)%3));
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};
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// Always start with first face (ccw in step will be sure to turn right
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// direction)
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const int f0 = EF(e,0);
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int fi = f0;
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int ei = e;
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while(true)
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{
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step(ei,fi,ei,fi);
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N.push_back(fi);
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// back to start?
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if(fi == f0)
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{
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assert(ei == e);
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break;
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}
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}
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return N;
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}
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IGL_INLINE void igl::circulation(
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const int e,
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const bool ccw,
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const Eigen::MatrixXi & F,
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const Eigen::MatrixXi & E,
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const Eigen::VectorXi & EMAP,
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const Eigen::MatrixXi & EF,
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const Eigen::MatrixXi & EI,
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Eigen::VectorXi & vN)
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{
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std::vector<int> N = circulation(e,ccw,F,E,EMAP,EF,EI);
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igl::list_to_matrix(N,vN);
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}
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