libcruft-util/matrix3.cpp

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/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Copyright 2015 Danny Robson <danny@nerdcruft.net>
*/
#include "./matrix.hpp"
using util::matrix;
///////////////////////////////////////////////////////////////////////////////
template <size_t S, typename T>
T
util::determinant (const matrix<S,T>& m)
{
static_assert (S == 3, "hard coded 3x3 specialisation");
return m[0][0] * (m[1][1] * m[2][2] - m[2][1] * m[1][2]) -
m[0][1] * (m[1][0] * m[2][2] - m[1][2] * m[2][0]) +
m[0][2] * (m[1][0] * m[2][1] - m[1][1] * m[2][0]);
}
template float util::determinant (const matrix<3,float>&);
template double util::determinant (const matrix<3,double>&);
//-----------------------------------------------------------------------------
template <size_t S, typename T>
matrix<S,T>
util::inverse (const matrix<S,T> &m)
{
static_assert (S == 3, "hard coded 3x3 specialisation");
return matrix<S,T> {
m[1][1] * m[2][2] - m[2][1] * m[1][2],
m[0][2] * m[2][1] - m[0][1] * m[2][2],
m[0][1] * m[1][2] - m[0][2] * m[1][1],
m[1][2] * m[2][0] - m[1][0] * m[2][2],
m[0][0] * m[2][2] - m[0][2] * m[2][0],
m[1][0] * m[0][2] - m[0][0] * m[1][2],
m[1][0] * m[2][1] - m[2][0] * m[1][1],
m[2][0] * m[0][1] - m[0][0] * m[2][1],
m[0][0] * m[1][1] - m[1][0] * m[0][1],
} / determinant (m);
}
template util::matrix<3,float> util::inverse (const matrix<3,float>&);
template util::matrix<3,double> util::inverse (const matrix<3,double>&);
///////////////////////////////////////////////////////////////////////////////
template struct util::matrix<3,float>;
template struct util::matrix<3,double>;