hitable_list.h

#ifndef HITABLELIST_H_
#define HITABLELIST_H_

#include "hitable.h"

class hitable_list :public hitable {
public:
	hitable_list() {}
	hitable_list(hitable** l, int n) { list = l; list_size = n; }
	virtual bool hit(const ray& r, double t_min, double t_max, hit_record& rec)const;
	virtual bool bounding_box(double t0, double t1, aabb& box)const;	//time0,time1
	hitable** list;
	int list_size;
};

bool hitable_list::hit(const ray& r, double t_min, double t_max, hit_record& rec)const {
	hit_record temp_rec;
	bool hit_anything = false;
	double closest_so_far = t_max;
	for (int i = 0; i < list_size; ++i) {//find closest object
		if (list[i]->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 hitable_list::bounding_box(double t0, double t1, aabb& box)const {
	if (list_size < 1)return false;
	aabb temp_box;
	bool first_true = list[0]->bounding_box(t0, t1, temp_box);		//是否能创建盒子
	if (!first_true)
		return false;
	else
		box = temp_box;
	for (int i = 1; i < list_size; ++i) {
		if (list[i]->bounding_box(t0, t1, temp_box)) {
			box = surrounding_box(box, temp_box);
		}
		else
			return false;
	}
	return true;
}

class box :public hitable {
public:
	box() {}
	box(const vec3& p0, const vec3& p1, material* ptr);
	virtual bool hit(const ray& r, double t_min, double t_max, hit_record& rec)const;		//纯虚函数，抽象类
	virtual bool bounding_box(double t0, double t1, aabb& box)const {	//time0,time1
		box = aabb(pmin, pmax);
		return true;
	}
	vec3 pmin, pmax;
	hitable* list_ptr;
};

box::box(const vec3& p0, const vec3& p1, material* ptr) {
	pmin = p0;
	pmax = p1;
	hitable** list = new hitable * [6];
	list[0] = new xy_rect(p0.x(), p1.x(), p0.y(), p1.y(), p1.z(), ptr);
	list[1] = new flip_normals(new xy_rect(p0.x(), p1.x(), p0.y(), p1.y(), p0.z(), ptr));
	list[2] = new xz_rect(p0.x(), p1.x(), p0.z(), p1.z(), p1.y(), ptr);
	list[3] = new flip_normals(new xz_rect(p0.x(), p1.x(), p0.z(), p1.z(), p0.y(), ptr));
	list[4] = new yz_rect(p0.y(), p1.y(), p0.z(), p1.z(), p1.x(), ptr);
	list[5] = new flip_normals(new yz_rect(p0.y(), p1.y(), p0.z(), p1.z(), p0.x(), ptr));
	list_ptr = new hitable_list(list, 6);
}

bool box::hit(const ray& r, double t_min, double t_max, hit_record& rec)const {
	return list_ptr->hit(r, t_min, t_max, rec);
}
#endif