64 lines
1.5 KiB
C++
64 lines
1.5 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) 2013 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 "transpose_blocks.h"
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#include <cassert>
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template <typename T>
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IGL_INLINE void igl::transpose_blocks(
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const Eigen::Matrix<T,Eigen::Dynamic,Eigen::Dynamic> & A,
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const size_t k,
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const size_t dim,
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Eigen::Matrix<T,Eigen::Dynamic,Eigen::Dynamic> & B)
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{
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// Eigen matrices must be 2d so dim must be only 1 or 2
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assert(dim == 1 || dim == 2);
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// Output is not allowed to be input
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assert(&A != &B);
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// block height, width, and number of blocks
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int m,n;
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if(dim == 1)
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{
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m = A.rows()/k;
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n = A.cols();
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}else// dim == 2
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{
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m = A.rows();
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n = A.cols()/k;
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}
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// resize output
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if(dim == 1)
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{
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B.resize(n*k,m);
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}else//dim ==2
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{
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B.resize(n,m*k);
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}
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// loop over blocks
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for(int b = 0;b<(int)k;b++)
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{
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if(dim == 1)
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{
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B.block(b*n,0,n,m) = A.block(b*m,0,m,n).transpose();
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}else//dim ==2
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{
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B.block(0,b*m,n,m) = A.block(0,b*n,m,n).transpose();
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}
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}
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}
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#ifdef IGL_STATIC_LIBRARY
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// Explicit template instantiation
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// generated by autoexplicit.sh
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template void igl::transpose_blocks<double>(Eigen::Matrix<double, -1, -1, 0, -1, -1> const&, size_t, size_t, Eigen::Matrix<double, -1, -1, 0, -1, -1>&);
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#endif
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