box.hpp

#ifndef LIBSBX_MATH_BOX_HPP_
#define LIBSBX_MATH_BOX_HPP_
 
#include <array>
 
#include <libsbx/math/concepts.hpp>
#include <libsbx/math/plane.hpp>
#include <libsbx/math/vector3.hpp>
 
namespace sbx::math {
 
template<scalar Type>
class basic_box {
 
public:
 
  using value_type = Type;
  using plane_type = basic_plane<value_type>;
  using volume_type = basic_volume<value_type>;
  using size_type = std::size_t;
 
  basic_box() noexcept = default;
 
  basic_box(const std::array<plane_type, 6u>& planes) noexcept
  : _planes{planes} { }
 
  basic_box(std::array<plane_type, 6u>&& planes) noexcept
  : _planes{std::move(planes)} { }
 
  auto intersects(const volume_type& volume) const -> bool {
    for (const auto& plane : planes()) {
      const auto vp = math::vector3{
        (plane.normal().x() >= 0 ? volume.max().x() : volume.min().x()),
        (plane.normal().y() >= 0 ? volume.max().y() : volume.min().y()),
        (plane.normal().z() >= 0 ? volume.max().z() : volume.min().z())
      };
 
      if (plane.distance_to_point(vp) < -0.5f) {
        return false;
      }
    }
 
    return true;
  }
 
  auto planes() const noexcept -> const std::array<plane_type, 6u>& {
    return _planes;
  }
 
  auto plane(const size_type index) const noexcept -> const plane_type& {
    return _planes[index];
  }
 
private:
 
  std::array<plane_type, 6u> _planes;
 
}; // class basic_box
 
using boxf = basic_box<std::float_t>;
 
using box = boxf;
 
} // namespace sbx::math
 
#endif // LIBSBX_MATH_BOX_HPP_