text: #ifndef HITABLEH
  #define HITABLEH
  
  #include "ray.h"
  
  class material;
  
  struct hit_record {
  	float t;
  	vec3 p;
  	vec3 normal;
  	material *mat_ptr;
  };
  
  class hitable {
  public:
  	__device__ virtual bool hit(const ray& r, float t_min, float t_max, hit_record& rec) const = 0;
  };
  
  #endif