copy_point.hpp

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#pragma once
 
#include <pcl/field_traits.h>
#include <pcl/type_traits.h>
#include <pcl/for_each_type.h>
#include <pcl/common/concatenate.h>
#include <pcl/common/copy_point.h>
 
#include <cstring>  // for memcpy
 
namespace pcl
{
 
namespace detail
{
 
/* CopyPointHelper and its specializations copy the contents of a source
 * point to a target point. There are three cases:
 *
 *  - Points have the same type.
 *    In this case a single `memcpy` is used.
 *
 *  - Points have different types and one of the following is true:
 *      * both have RGB fields;
 *      * both have RGBA fields;
 *      * one or both have no RGB/RGBA fields.
 *    In this case we find the list of common fields and copy their
 *    contents one by one with `NdConcatenateFunctor`.
 *
 *  - Points have different types and one of these types has RGB field, and
 *    the other has RGBA field.
 *    In this case we also find the list of common fields and copy their
 *    contents. In order to account for the fact that RGB and RGBA do not
 *    match we have an additional `memcpy` to copy the contents of one into
 *    another.
 *
 * An appropriate version of CopyPointHelper is instantiated during
 * compilation time automatically, so there is absolutely no run-time
 * overhead. */
 
template <typename PointInT, typename PointOutT, typename Enable = void>
struct CopyPointHelper { };
 
template <typename PointInT, typename PointOutT>
struct CopyPointHelper<PointInT, PointOutT, std::enable_if_t<std::is_same<PointInT, PointOutT>::value>>
{
  void operator () (const PointInT& point_in, PointOutT& point_out) const
  {
    memcpy (&point_out, &point_in, sizeof (PointInT));
  }
};
 
template <typename PointInT, typename PointOutT>
struct CopyPointHelper<PointInT, PointOutT,
                       std::enable_if_t<boost::mpl::and_<boost::mpl::not_<std::is_same<PointInT, PointOutT>>,
                                                         boost::mpl::or_<boost::mpl::not_<pcl::traits::has_color<PointInT>>,
                                                                         boost::mpl::not_<pcl::traits::has_color<PointOutT>>,
                                                                         boost::mpl::and_<pcl::traits::has_field<PointInT, pcl::fields::rgb>,
                                                                                          pcl::traits::has_field<PointOutT, pcl::fields::rgb>>,
                                                                         boost::mpl::and_<pcl::traits::has_field<PointInT, pcl::fields::rgba>,
                                                                                          pcl::traits::has_field<PointOutT, pcl::fields::rgba>>>>::value>>
{
  void operator () (const PointInT& point_in, PointOutT& point_out) const
  {
    using FieldListInT = typename pcl::traits::fieldList<PointInT>::type;
    using FieldListOutT = typename pcl::traits::fieldList<PointOutT>::type;
    using FieldList = typename pcl::intersect<FieldListInT, FieldListOutT>::type;
    pcl::for_each_type <FieldList> (pcl::NdConcatenateFunctor <PointInT, PointOutT> (point_in, point_out));
  }
};
 
template <typename PointInT, typename PointOutT>
struct CopyPointHelper<PointInT, PointOutT,
                       std::enable_if_t<boost::mpl::and_<boost::mpl::not_<std::is_same<PointInT, PointOutT>>,
                                        boost::mpl::or_<boost::mpl::and_<pcl::traits::has_field<PointInT, pcl::fields::rgb>,
                                                                         pcl::traits::has_field<PointOutT, pcl::fields::rgba>>,
                                                        boost::mpl::and_<pcl::traits::has_field<PointInT, pcl::fields::rgba>,
                                                                         pcl::traits::has_field<PointOutT, pcl::fields::rgb>>>>::value>>
{
  void operator () (const PointInT& point_in, PointOutT& point_out) const
  {
    using FieldListInT = typename pcl::traits::fieldList<PointInT>::type;
    using FieldListOutT = typename pcl::traits::fieldList<PointOutT>::type;
    using FieldList = typename pcl::intersect<FieldListInT, FieldListOutT>::type;
    constexpr std::uint32_t offset_in  = boost::mpl::if_<pcl::traits::has_field<PointInT, pcl::fields::rgb>,
                                                pcl::traits::offset<PointInT, pcl::fields::rgb>,
                                                pcl::traits::offset<PointInT, pcl::fields::rgba> >::type::value;
    constexpr std::uint32_t offset_out = boost::mpl::if_<pcl::traits::has_field<PointOutT, pcl::fields::rgb>,
                                                pcl::traits::offset<PointOutT, pcl::fields::rgb>,
                                                pcl::traits::offset<PointOutT, pcl::fields::rgba> >::type::value;
    pcl::for_each_type <FieldList> (pcl::NdConcatenateFunctor <PointInT, PointOutT> (point_in, point_out));
    memcpy (reinterpret_cast<char*> (&point_out) + offset_out,
            reinterpret_cast<const char*> (&point_in) + offset_in,
            4);
  }
};
 
} // namespace detail
 
template <typename PointInT, typename PointOutT> void
copyPoint (const PointInT& point_in, PointOutT& point_out)
{
  detail::CopyPointHelper<PointInT, PointOutT> copy;
  copy (point_in, point_out);
}
 
} // namespace pcl