to_rotation_matrix

kyosu::to_rotation_matrix = eve::functor<to_rotation_matrix_t>

inlineconstexpr

Callable object computing a quaternion from its to_rotation_matrix representation.

This function build rotation_matrix angles from a quaternion.

Header file

#include kyosu/quaternion.hpp>`

Callable Signatures

namespace eve
{
    auto to_rotation_matrix(auto q) const noexcept;                   //1
    auto to_rotation_matrix[assume_unitary](auto q) const noexcept;   //2
}

Parameters

• q quaternion representing the rotation

Return value

1. compute the rotation matrix associated to the quaternion.
2. with assume_unitary, assumes that q is already normalized

if T is the element type of q, returns an std::array<std::array<T, 3>, 3> containing the 9 coefficients of the rotation matrix

Note

use this function if you really need the rotation matrix, but to rotate vectors prefer the function rot_vec that directly uses the quaternion.

Example

#include <kyosu/kyosu.hpp>
#include <eve/wide.hpp>
#include <iostream>
 
int main()
{
  using kyosu::to_rotation_matrix;
  using kyosu::complex_t;
  using kyosu::quaternion_t;
  using q_t = kyosu::quaternion_t<float>;
 
  std::cout << "Quaternion:  "<< "\n";
  q_t q0(1, 5, 2, 3);
  auto m = to_rotation_matrix(q0);
  std::cout << "q0 =  " << q0 << std::endl;
  std::cout << "to_rotation_matrix(q0) = \n";
  for(int i=0; i <3 ; ++i)
  {
    std::cout << "    ";
    for(int j=0; j < 2 ; ++j)
    {
      std::cout << m[i][j] << ", ";
    }
    std::cout << m[i][2] << "\n";
  }
  return 0;
}