File size: 1,700 Bytes
fe775b6 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 | #ifndef IGL_LINSPACED_H
#define IGL_LINSPACED_H
#include <Eigen/Core>
// This function is not intended to be a permanent function of libigl. Rather
// it is a "drop-in" workaround for documented bug in Eigen:
// http://eigen.tuxfamily.org/bz/show_bug.cgi?id=1383
//
// Replace:
//
// Eigen::VectorXi::LinSpaced(size,low,high);
//
// With:
//
// igl::LinSpaced<Eigen::VectorXi>(size,low,high);
//
// Specifcally, this version will _always_ return an empty vector if size==0,
// regardless of the values for low and high. If size != 0, then this simply
// returns the result of Eigen::Derived::LinSpaced.
//
// Until this bug is fixed, we should also avoid calls to the member function
// `.setLinSpaced`. This means replacing:
//
// a.setLinSpaced(size,low,high);
//
// with
//
// a = igl::LinSpaced<decltype(a) >(size,low,high);
//
namespace igl
{
template <typename Derived>
//inline typename Eigen::DenseBase< Derived >::RandomAccessLinSpacedReturnType
inline Derived LinSpaced(
typename Derived::Index size,
const typename Derived::Scalar & low,
const typename Derived::Scalar & high);
}
// Implementation
template <typename Derived>
//inline typename Eigen::DenseBase< Derived >::RandomAccessLinSpacedReturnType
inline Derived
igl::LinSpaced(
typename Derived::Index size,
const typename Derived::Scalar & low,
const typename Derived::Scalar & high)
{
if(size == 0)
{
// Force empty vector with correct "RandomAccessLinSpacedReturnType" type.
return Derived::LinSpaced(0,0,1);
}else if(high < low)
{
return low-Derived::LinSpaced(size,low-low,low-high).array();
}else{
return Derived::LinSpaced(size,low,high);
}
}
#endif
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