Invert.hpp

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// Copyright (c) 2019 Maikel Nadolski
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
 
#ifndef FUB_GEOMETRY_INVERT_HPP
#define FUB_GEOMETRY_INVERT_HPP
 
#include "fub/core/type_traits.hpp"
 
#include <array>
 
namespace fub {
namespace meta {
template <typename T, typename... Args>
using ComputeDistanceTo =
    decltype(std::declval<T>().ComputeDistanceTo(std::declval<Args>()...));
}
 
template <typename Base> class Invert : private Base {
public:
  Invert(const Base& base) : Base(base) {}
 
  [[nodiscard]] double ComputeDistanceTo(std::array<double, 3> x) const
      noexcept {
    if constexpr (is_detected<meta::ComputeDistanceTo, const Base&,
                              std::array<double, 3>>()) {
      return -Base::ComputeDistanceTo(x);
    } else if constexpr (is_detected<meta::ComputeDistanceTo, const Base&,
                                     std::array<double, 2>>()) {
      std::array<double, 2> proj{x[0], x[1]};
      return -Base::ComputeDistanceTo(proj);
    } else {
      return -Base::ComputeDistanceTo(x[0]);
    }
  }
 
  [[nodiscard]] double ComputeDistanceTo(std::array<double, 2> x) const
      noexcept {
    if constexpr (is_detected<meta::ComputeDistanceTo, const Base&,
                              std::array<double, 2>>()) {
      return -Base::ComputeDistanceTo(x);
    } else if constexpr (is_detected<meta::ComputeDistanceTo, const Base&,
                                     std::array<double, 3>>()) {
      std::array<double, 3> proj{x[0], x[1]};
      return -Base::ComputeDistanceTo(proj);
    } else {
      return -Base::ComputeDistanceTo(x[0]);
    }
  }
};
 
} // namespace fub
 
#endif