libcruft-util/matrix2.cpp

65 lines
1.9 KiB
C++

/*
* 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 == 2, "partial specialization for 2 dimensions");
return m[0][0] * m[1][1] - m[0][1] * m[1][0];
}
template float util::determinant (const matrix<2,float>&);
template double util::determinant (const matrix<2,double>&);
//-----------------------------------------------------------------------------
template <size_t S, typename T>
matrix<S,T>
util::inverse (const matrix<S,T> &m)
{
static_assert (S == 2, "partial specialization for 2 dimensions");
return matrix<S,T> {
m[1][1], -m[0][1],
-m[1][0], m[0][0]
} / determinant (m);
}
template util::matrix<2,float> util::inverse (const matrix<2,float>&);
template util::matrix<2,double> util::inverse (const matrix<2,double>&);
///////////////////////////////////////////////////////////////////////////////
template <size_t S, typename T>
const matrix<S,T>
matrix<S,T>::IDENTITY = { {
{ 1, 0, },
{ 0, 1 }
} };
///////////////////////////////////////////////////////////////////////////////
template struct util::matrix<2,float>;
template struct util::matrix<2,double>;