libcruft-util/quaternion.cpp

79 lines
2.3 KiB
C++

/*
* This file is part of libgim.
*
* libgim is free software: you can redistribute it and/or modify it under the
* terms of the GNU General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later
* version.
*
* libgim is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with libgim. If not, see <http://www.gnu.org/licenses/>.
*
* Copyright 2011 Danny Robson <danny@nerdcruft.net>
*/
#include "quaternion.hpp"
//-----------------------------------------------------------------------------
using util::quaternion;
//-----------------------------------------------------------------------------
template<> const quaternion<float> quaternion<float>::IDENTITY = { 1, 0, 0, 0 };
template<> const quaternion<double> quaternion<double>::IDENTITY = { 1, 0, 0, 0 };
//-----------------------------------------------------------------------------
template <typename T>
quaternion<T>
quaternion<T>::rotation (T radians, vector<3,T> axis) {
radians /= T{2};
axis.normalise ();
return {
std::cos (radians),
axis.x * std::sin (radians),
axis.y * std::sin (radians),
axis.z * std::sin (radians)
};
}
//-----------------------------------------------------------------------------
template <typename T>
quaternion<T>
quaternion<T>::rotation (vector<3,T> from, vector<3,T> to) {
auto v = util::cross (from, to);
return {
std::acos (dot (from, to)),
v.x,
v.y,
v.z
};
}
//-----------------------------------------------------------------------------
template <typename T>
quaternion<T>
quaternion<T>::operator* (const quaternion<T> &rhs) const {
return {
w * rhs.w - (x * rhs.x + y * rhs.y + z * rhs.z),
w * rhs.x + rhs.w * x + y * rhs.z - z * rhs.y,
w * rhs.y + rhs.w * y + z * rhs.x - x * rhs.z,
w * rhs.z + rhs.w * z + x * rhs.y - y * rhs.x
};
}
//-----------------------------------------------------------------------------
template struct util::quaternion<float>;
template struct util::quaternion<double>;