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add optimized cross3 function (code from Rohit Garg)

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This commit is contained in:
Gael Guennebaud
2009-03-11 14:20:36 +00:00
parent 3298320007
commit b8f46090ff
4 changed files with 70 additions and 0 deletions
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44
Eigen/src/Geometry/OrthoMethods.h
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@@ -31,6 +31,7 @@
* \returns the cross product of \c *this and \a other
*
* Here is a very good explanation of cross-product: http://xkcd.com/199/
* \sa MatrixBase::cross3()
*/
template<typename Derived>
template<typename OtherDerived>
@@ -38,6 +39,7 @@ inline typename MatrixBase<Derived>::PlainMatrixType
MatrixBase<Derived>::cross(const MatrixBase<OtherDerived>& other) const
{
EIGEN_STATIC_ASSERT_VECTOR_SPECIFIC_SIZE(Derived,3)
EIGEN_STATIC_ASSERT_VECTOR_SPECIFIC_SIZE(OtherDerived,3)
// Note that there is no need for an expression here since the compiler
// optimize such a small temporary very well (even within a complex expression)
@@ -50,6 +52,48 @@ MatrixBase<Derived>::cross(const MatrixBase<OtherDerived>& other) const
);
}
template< int Arch,typename VectorLhs,typename VectorRhs,
typename Scalar = typename VectorLhs::Scalar,
int Vectorizable = (VectorLhs::Flags&VectorRhs::Flags)&PacketAccessBit>
struct ei_cross3_impl {
inline static typename ei_plain_matrix_type<VectorLhs>::type
run(const VectorLhs& lhs, const VectorRhs& rhs)
{
return typename ei_plain_matrix_type<VectorLhs>::type(
lhs.coeff(1) * rhs.coeff(2) - lhs.coeff(2) * rhs.coeff(1),
lhs.coeff(2) * rhs.coeff(0) - lhs.coeff(0) * rhs.coeff(2),
lhs.coeff(0) * rhs.coeff(1) - lhs.coeff(1) * rhs.coeff(0),
0
);
}
};
/** \geometry_module
*
* \returns the cross product of \c *this and \a other using only the x, y, and z coefficients
*
* The size of \c *this and \a other must be four. This function is especially useful
* when using 4D vectors instead of 3D ones to get advantage of SSE/AltiVec vectorization.
*
* \sa MatrixBase::cross()
*/
template<typename Derived>
template<typename OtherDerived>
inline typename MatrixBase<Derived>::PlainMatrixType
MatrixBase<Derived>::cross3(const MatrixBase<OtherDerived>& other) const
{
EIGEN_STATIC_ASSERT_VECTOR_SPECIFIC_SIZE(Derived,4)
EIGEN_STATIC_ASSERT_VECTOR_SPECIFIC_SIZE(OtherDerived,4)
typedef typename ei_nested<Derived,2>::type DerivedNested;
typedef typename ei_nested<OtherDerived,2>::type OtherDerivedNested;
const DerivedNested lhs(derived());
const OtherDerivedNested rhs(other.derived());
return ei_cross3_impl<EiArch,typename ei_cleantype<DerivedNested>::type,
typename ei_cleantype<OtherDerivedNested>::type>::run(lhs,rhs);
}
/** \returns a matrix expression of the cross product of each column or row
* of the referenced expression with the \a other vector.
*