testPointFunctorHolder.cpp

 
#include <iostream>
#include <cmath>
 
#include "DGtal/kernel/CPointFunctor.h"
#include "DGtal/kernel/PointVector.h"
#include "DGtal/kernel/PointFunctorHolder.h"
 
#include "DGtalCatch.h"
 
template <typename T, typename Point>
T kernel(Point const& pt, Point const& center, T radius)
{
  return (pt - center).norm() - radius;
}
 
template <typename T, typename Point>
struct Functor
{
  Point center;
  T radius;
 
  Functor(Point const& c, T r)
    : center(c), radius(r)
  {}
  Functor(Point const& c, T r) {…}
 
  T operator() (Point const& pt) const
    {
      return kernel<T>(pt, center, radius);
    }
  T operator() (Point const& pt) const {…}
};
 
TEST_CASE( "2D PointFunctorHolder from functor by rvalue", "[2D][functor][rvalue]" )
{
  using namespace DGtal;
  using Point = PointVector<2, int>;
  using Value = double;
 
  auto fn = functors::holdPointFunctor<Point, Value>( Functor<Value, Point>( Point(1, 0), 1 ) );
 
  // Checks CPointFunctor concept.
  BOOST_CONCEPT_ASSERT( (DGtal::concepts::CPointFunctor<decltype(fn)>) );
  
  // Checking standard services
  std::cout << fn << std::endl;
  REQUIRE( fn.isValid() );
 
  // Checking operator()
  REQUIRE( fn(Point(2, 1)) == Approx( std::sqrt(2) - 1. ) );
}
 
TEST_CASE( "2D PointFunctorHolder from functor by lvalue", "[2D][functor][lvalue]" )
{
  using namespace DGtal;
  using Point = PointVector<2, int>;
  using Value = double;
 
  const auto functor = Functor<Value, Point>( Point(1, 0), 1 );
  auto fn = functors::holdPointFunctor<Point>( functor ); // auto deduction of the return type
 
  // Checks CPointFunctor concept.
  BOOST_CONCEPT_ASSERT( (DGtal::concepts::CPointFunctor<decltype(fn)>) );
 
  // Checking standard services
  std::cout << fn << std::endl;
  REQUIRE( fn.isValid() );
 
  // Checking operator()
  REQUIRE( fn(Point(2, 1)) == Approx( std::sqrt(2) - 1. ) );
}
 
TEST_CASE( "2D PointFunctorHolder from lambda by rvalue", "[2D][lambda][rvalue]" )
{
  using namespace DGtal;
  using Point = PointVector<2, int>;
  using Value = double;
 
  const Point center(1, 0);
  const Value radius = 1;
 
  auto fn = functors::holdPointFunctor<Point, Value>(
    [&center, &radius] (Point const& pt) { return kernel<Value>(pt, center, radius); }
  );
 
  // Checks CPointFunctor concept.
  BOOST_CONCEPT_ASSERT( (DGtal::concepts::CPointFunctor<decltype(fn)>) );
 
  // Checking standard services
  std::cout << fn << std::endl;
  REQUIRE( fn.isValid() );
 
  // Checking operator()
  REQUIRE( fn(Point(2, 1)) == Approx( std::sqrt(2) - 1. ) );
}
 
TEST_CASE( "2D PointFunctorHolder from lambda by lvalue", "[2D][lambda][lvalue]" )
{
  using namespace DGtal;
  using Point = PointVector<2, int>;
  using Value = double;
 
  const Point center(1, 0);
  const Value radius = 1;
 
  const auto lambda = [&center, &radius] (Point const& pt) { return kernel<Value>(pt, center, radius); };
  auto fn = functors::holdPointFunctor<Point, Value>( lambda );
 
  // Checks CPointFunctor concept.
  BOOST_CONCEPT_ASSERT( (DGtal::concepts::CPointFunctor<decltype(fn)>) );
 
  // Checking standard services
  std::cout << fn << std::endl;
  REQUIRE( fn.isValid() );
 
  // Checking operator()
  REQUIRE( fn(Point(2, 1)) == Approx( std::sqrt(2) - 1. ) );
}