hittable_list.h

#ifndef HITTABLE_LIST
#define HITTABLE_LIST

#include "hittable.h"


#include<memory> // for std::make_shared
#include<vector>


// retain shared ownership of object through pointer
using std::make_shared;
using std::shared_ptr;


class hittable_list : public hittable {
public:
    std::vector<shared_ptr<hittable>> objects;

    hittable_list() {}
    hittable_list(shared_ptr<hittable> object) { add(object); }

    void clear() { objects.clear(); }

    void add(shared_ptr<hittable> object) {
        objects.push_back(object);
    }


    // Checking if ray intersects in given interval time , tmin -- tmax
    bool hit(const ray& r, double ray_tmin, double ray_tmax, hit_record& rec) const override {
        hit_record temp_rec;
        bool hit_anything = false;
        auto closest_so_far = ray_tmax;

         // const reference to object
        for (const auto& object : objects) {
            if (object->hit(r, ray_tmin, closest_so_far, temp_rec)) {
                hit_anything = true;
                closest_so_far = temp_rec.t;
                rec = temp_rec;
            }
        }

        return hit_anything;
    }
};


#endif // !HITTABLE_LIST