aabb.h

#ifndef AABB_H
#define AABB_H

#include "rtweekend.h"

class aabb {
    public:
	aabb() {}
	aabb(const point3& a, const point3& b) {minimum = a; maximum = b;}

	point3 min() const {return minimum; }
	point3 max() const {return maximum; }

	bool hit(const ray& r, double t_min, double t_max) const {
	    for (int a = 0; a < 3; a++) {
		auto t0 = fmin((minimum[a] - r.origin()[a]) / r.direction()[a],
			       (maximum[a] - r.origin()[a]) / r.direction()[a]);
		auto t1 = fmax((minimum[a] - r.origin()[a]) / r.direction()[a],
			       (maximum[a] - r.origin()[a]) / r.direction()[a]);
		t_min = fmax(t0, t_min);
		t_max = fmin(t1, t_max);
		if (t_max <= t_min) {
		    return false;
		}
	    }
	    return true;
	}





	point3 minimum;
	point3 maximum;
};




aabb surrounding_box(aabb box0, aabb box1) {
    point3 small(fmin(box0.min().x(), box1.min().x()),
		  fmin(box0.min().y(), box1.min().y()),
		  fmin(box0.min().z(), box1.min().z()));

    point3 big (fmax(box0.max().x(), box1.max().x()),
		fmax(box0.max().y(), box1.max().y()),
		fmax(box0.max().z(), box1.max().z()));

    return aabb(small,big);
}

/* Alt hit function
	bool hit(const ray& r, double t_min, double t_max) const {
    	    for (int a = 0; a < 3; a++) {
		auto invD = 1.0f / r.direction()[a];
		auto t0 = (min()[a] - r.origin()[a]) * invD;
		auto t1 = (max()[a] - r.origin()[a]) * invD;
		if (invD < 0.0f){
    	    	    std::swap(t0, t1);
		}
		t_min = t0 > t_min ? t0 : t_min;
		t_max = t1 < t_max ? t1 : t_max;
		if (t_max <= t_min) {
    	    	    return false;
		}
    	    }
    	return true;
	}
*/

#endif