/* ray.h                                                 -*-C++-*-
 *   by Will Wagner <wwagner@io.com>
 *   last updated 20 Sep 1997, 17:33:50 wwagner
 *
 * This file contains the Intersection and Ray primitives for POVRay.
 *
 * Changes
 *   11 Aug 1997
 *     - Added this comment block
 *
 *   20 Sep 1997
 *     - Minor changes.
 *
 * Things to do
 *
 */

#ifndef __INC_RAY_H__
#define __INC_RAY_H__

#include <g++/list.h>
#include <g++/stack.h>
#include "frame.h"
#include "vector.h"
#include "object.h"

class Intersection
{
  private:
    DBL depth;
    pov_vector<DBL> ipoint, inormal;
    Object *object;
    int i1, i2;
    DBL d1, d2;
    void *pointer;

  public:
    Intersection();
    Intersection(DBL, pov_vector<DBL>&, Object *, pov_vector<DBL>&);
    Intersection(DBL, pov_vector<DBL>&, Object *, void *);
    Intersection(DBL, pov_vector<DBL>&, Object *, int, DBL = 0.0);
    Intersection(DBL, pov_vector<DBL>&, Object *, int, int, DBL = 0.0);
    Intersection(DBL, pov_vector<DBL>&, Object *, DBL);
    ~Intersection();
};

/* We can use a normal STL list and a stack adapter for the IStack. */
typedef stack< list<Intersection> > IStack;

/* The following defines control the initial size and overflow
 * expansion factor of the vector containing member of Ray.  The
 * Ray object will never overflow as before; if you've got the memory
 * and the time, we've got the code.
 */
#define INITIAL_CONTAINING_OBJECTS 100
#define CONTAINING_OBJECTS_FACTOR 2

class Ray
{
  private:
    pov_vector<DBL> initial, direction;
    typedef struct ray_containing_struct
    {
        Texture *texture;
	Object *object;
	DBL ior;
    }
    ray_struct;
    vector<ray_struct> containing;

    static int ray_struct_compare(ray_struct&, Texture *);

  public:
    Ray();
    Ray(const pov_vector<DBL>&, const pov_vector<DBL>&);
    Ray(const Ray&);
    ~Ray();

    void Enter(Object *, Texture *);
    void Exit(int);
    int TextureInRay(Texture *);
};

#endif /* __INC_RAY_H__ */