libigl/include/igl/svd3x3_sse.h

// This file is part of libigl, a simple c++ geometry processing library.
// 
// Copyright (C) 2013 Alec Jacobson <[email protected]>
// 
// 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_SVD3X3_SSE_H
#define IGL_SVD3X3_SSE_H
#include "igl_inline.h"
#include <Eigen/Dense>

namespace igl
{
  // Super fast 3x3 SVD according to http://pages.cs.wisc.edu/~sifakis/project_pages/svd.html
  // This is SSE version of svd3x3 (see svd3x3.h) which works on 4 matrices at a time
  // These four matrices are simply stacked in columns, the rest is the same as for svd3x3
  //
  /// @param[in] A  12 by 3 stack of 3x3 matrices
  /// @param[out] U  12x3 left singular vectors stacked
  /// @param[out] S  12x1 singular values stacked
  /// @param[out] V  12x3 right singular vectors stacked
  ///
  /// \bug this will not work correctly for double precision.
  template<typename T>
  IGL_INLINE void svd3x3_sse(
    const Eigen::Matrix<T, 3*4, 3>& A, 
    Eigen::Matrix<T, 3*4, 3> &U, 
    Eigen::Matrix<T, 3*4, 1> &S, 
    Eigen::Matrix<T, 3*4, 3>&V);
}
#ifndef IGL_STATIC_LIBRARY
#  include "svd3x3_sse.cpp"
#endif
#endif