Sprout/sprout/darkroom/rays/ray.hpp
2019-01-07 17:47:17 +09:00

97 lines
3.1 KiB
C++

/*=============================================================================
Copyright (c) 2011-2019 Bolero MURAKAMI
https://github.com/bolero-MURAKAMI/Sprout
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
=============================================================================*/
#ifndef SPROUT_DARKROOM_RAYS_RAY_HPP
#define SPROUT_DARKROOM_RAYS_RAY_HPP
#include <sprout/config.hpp>
#include <sprout/limits.hpp>
#include <sprout/tuple/tuple.hpp>
#include <sprout/utility/forward.hpp>
#include <sprout/darkroom/access/access.hpp>
#include <sprout/darkroom/coords/vector.hpp>
namespace sprout {
namespace darkroom {
namespace rays {
//
// position
// direction
//
template<typename T>
inline SPROUT_CONSTEXPR auto
position(T&& t)
SPROUT_NOEXCEPT_IF_EXPR(sprout::darkroom::access::get<0>(SPROUT_FORWARD(T, t)))
-> decltype(sprout::darkroom::access::get<0>(SPROUT_FORWARD(T, t)))
{
return sprout::darkroom::access::get<0>(SPROUT_FORWARD(T, t));
}
template<typename T>
inline SPROUT_CONSTEXPR auto
direction(T&& t)
SPROUT_NOEXCEPT_IF_EXPR(sprout::darkroom::access::get<1>(SPROUT_FORWARD(T, t)))
-> decltype(sprout::darkroom::access::get<1>(SPROUT_FORWARD(T, t)))
{
return sprout::darkroom::access::get<1>(SPROUT_FORWARD(T, t));
}
//
// make_ray
//
template<typename Position, typename Direction>
inline SPROUT_CONSTEXPR sprout::tuples::tuple<Position, Direction>
make_ray(Position const& pos, Direction const& dir) {
return sprout::tuples::make_tuple(pos, dir);
}
//
// ray
//
typedef sprout::tuples::tuple<sprout::darkroom::coords::vector3d_t, sprout::darkroom::coords::vector3d_t> ray;
//
// point_of_intersection
//
template<typename Ray, typename Distance>
inline SPROUT_CONSTEXPR typename sprout::darkroom::access::unit<Ray>::type
point_of_intersection(Ray const& ray, Distance const& dist) {
return sprout::darkroom::coords::add(
sprout::darkroom::rays::position(ray),
sprout::darkroom::coords::scale(sprout::darkroom::rays::direction(ray), dist)
);
}
//
// detach_position
//
template<typename Position, typename Direction>
inline SPROUT_CONSTEXPR Position
detach_position(Position const& pos, Direction const& dir) {
return sprout::darkroom::coords::add(
pos,
sprout::darkroom::coords::resize(
dir,
sprout::numeric_limits<typename sprout::darkroom::access::unit<Direction>::type>::epsilon() * 256
)
);
}
//
// make_detached_ray
//
template<typename Position, typename Direction>
inline SPROUT_CONSTEXPR sprout::tuples::tuple<Position, Direction>
make_detached_ray(Position const& pos, Direction const& dir) {
return sprout::darkroom::rays::make_ray(
sprout::darkroom::rays::detach_position(pos, dir),
dir
);
}
} // namespace rays
} // namespace darkroom
} // namespace sprout
#endif // #ifndef SPROUT_DARKROOM_RAYS_RAY_HPP