hittable_list.hpp

#ifndef HITTABLE_LIST_HPP
#define HITTABLE_LIST_HPP

#include "hittable.hpp"
#include "aabb.hpp"

#include <memory>
#include <vector>

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

class hittable_list : public hittable {
public:
    hittable_list() = default;
    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 override;
    virtual bool bounding_box(double time0, double time1, aabb& output_box) const override;
    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;

    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;
}

bool hittable_list::bounding_box(double time0, double time1, aabb& output_box) const {
    if (objects.empty()) return false;

    aabb temp_box;
    bool first_box = true;

    for (const auto& object : objects) {
        if (!object->bounding_box(time0, time1, temp_box)) return false;
        output_box = first_box ? temp_box : surrounding_box(output_box, temp_box);
        first_box = false;
    }

    return true;
}
#endif