55 lines
1.4 KiB
C++
55 lines
1.4 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) 2014 Stefan Brugger <stefanbrugger@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 "map_vertices_to_circle.h"
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#include "PI.h"
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IGL_INLINE void igl::map_vertices_to_circle(
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const Eigen::MatrixXd& V,
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const Eigen::VectorXi& bnd,
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Eigen::MatrixXd& UV)
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{
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// Get sorted list of boundary vertices
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std::vector<int> interior,map_ij;
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map_ij.resize(V.rows());
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std::vector<bool> isOnBnd(V.rows(),false);
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for (int i = 0; i < bnd.size(); i++)
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{
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isOnBnd[bnd[i]] = true;
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map_ij[bnd[i]] = i;
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}
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for (int i = 0; i < (int)isOnBnd.size(); i++)
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{
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if (!isOnBnd[i])
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{
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map_ij[i] = interior.size();
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interior.push_back(i);
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}
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}
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// Map boundary to unit circle
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std::vector<double> len(bnd.size());
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len[0] = 0.;
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for (int i = 1; i < bnd.size(); i++)
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{
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len[i] = len[i-1] + (V.row(bnd[i-1]) - V.row(bnd[i])).norm();
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}
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double total_len = len[len.size()-1] + (V.row(bnd[0]) - V.row(bnd[bnd.size()-1])).norm();
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UV.resize(bnd.size(),2);
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for (int i = 0; i < bnd.size(); i++)
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{
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double frac = len[i] * 2. * igl::PI / total_len;
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UV.row(map_ij[bnd[i]]) << cos(frac), sin(frac);
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}
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}
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