dust3d/third_party/libigl/include/igl/axis_angle_to_quat.cpp

43 lines
1.2 KiB
C++

// This file is part of libigl, a simple c++ geometry processing library.
//
// Copyright (C) 2013 Alec Jacobson <alecjacobson@gmail.com>
//
// 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/.
#include "axis_angle_to_quat.h"
#include "EPS.h"
#include <cmath>
// http://www.antisphere.com/Wiki/tools:anttweakbar
template <typename Q_type>
IGL_INLINE void igl::axis_angle_to_quat(
const Q_type *axis,
const Q_type angle,
Q_type *out)
{
Q_type n = axis[0]*axis[0] + axis[1]*axis[1] + axis[2]*axis[2];
if( fabs(n)>igl::EPS<Q_type>())
{
Q_type f = 0.5*angle;
out[3] = cos(f);
f = sin(f)/sqrt(n);
out[0] = axis[0]*f;
out[1] = axis[1]*f;
out[2] = axis[2]*f;
}
else
{
out[3] = 1.0;
out[0] = out[1] = out[2] = 0.0;
}
}
#ifdef IGL_STATIC_LIBRARY
// Explicit template instantiation
// generated by autoexplicit.sh
template void igl::axis_angle_to_quat<double>(double const*, double, double*);
// generated by autoexplicit.sh
template void igl::axis_angle_to_quat<float>(float const*, float, float*);
#endif