hittable_list.h

#ifndef HITTABLE_LIST_H
#define HITTABLE_LIST_H

#include <memory>
#include <vector>

#include "hittable.h"

using std::make_shared;
using std::shared_ptr;

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

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

    virtual bool hit(const ray& r, double t_min, double t_max,
                     hit_record& rec) const;

   private:
    std::vector<shared_ptr<hittable>> objects;
};

bool hittable_list::hit(const ray& r, double t_min, double t_max,
                        hit_record& rec) const {
    hit_record temp_rec;
    bool hit_anything = false;
    auto closest_so_far = t_max;    // A ray can only hit the closest object
    for (const auto& object : objects) {
        if (object->hit(r, t_min, closest_so_far, temp_rec)) {
            hit_anything = true;
            closest_so_far = temp_rec.t;
            rec = temp_rec;
        }
    }
    return hit_anything;
}

#endif