ray.h

 
#pragma once
 
#include "geometry_common.h"
 
namespace ghassanpl::geometry
{

    template <std::floating_point T>
    struct tray
    {
 
        using tvec = glm::tvec2<T>;
        using value_type = T;
        using segment = tsegment<T>;
 
        tvec start{};
        tvec dir{}; 
 
        basic_line_t<T> line() const noexcept { return line_from_dir(dir); }
 
        tray from_dir(tvec const& start, tvec const& dir) noexcept { return { start, glm::normalize(dir) }; }
        tray from_points(tvec const& start, tvec const& second) noexcept { return from_dir(start, second - start); }
        
        segment& set_position(tvec const& pos) noexcept { start = pos; return *this; }
        segment& operator+=(tvec const& offs) noexcept { start += offs; return *this; }
        segment& operator-=(tvec const& offs) noexcept { start -= offs; return *this; }
        segment& translate(tvec const& offs) noexcept { return this->operator+=(offs); }
 
        T edge_length() const noexcept { return std::numeric_limits<T>::infinity(); }
 
        tvec edge_point(T t) const { return start + dir * t; }
        trec2<T> bounding_box() const { return trec2<T>::from_points(edge_point(T{}), edge_point(edge_length())); }
        tvec closest_point_to(tvec const& pt) const
        {
            const auto a = projected_alpha(pt);
            if (a < T(0)) return start;
            return start + dir * a;
        }
        T projected_alpha(tvec const& pt) const
        {
            const auto d = pt - start;
            return glm::dot(d, dir);
        }
    };
 
    using ray = tray<float>;
 
}