Source: raytracer/boundingbox.h

/* *************************************************************************
                          boundingbox.h  -  description
                             -------------------
    begin                : Wed Oct 16 2002
    copyright            : (C) 2002 by Micha Riser
    email                : mriser@gmx.net
 ************************************************************************* */

/* *************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ************************************************************************* */

#ifndef BOUNDINGBOX_H
#define BOUNDINGBOX_H

#include "vector.h"
#include "transformatable.h"
#include "limits.h"
#include "statistics.h"

/**A boundingbox encloses the object's surface. The whole surface is inside the
  *box between boxmin and boxmax. Each finit object should have a boundingbox to
  *allow creation of a BB hirarchy.
  *Boundingboxes are in upper-level space and always axes-aligned.
  *@author Micha Riser
  */  
class BoundingBox {

public: // Constructors and destructor

    /**Generates a bounding box from two edge points. All components of
      *edgemin have to be smaller than the corresponding components of
      *edgemax.
      */
    BoundingBox(Vector3 edgemin, Vector3 edgemax): boxmin(edgemin), boxmax(edgemax) {}

public: // Public methods

    /**
      *@returns Minimum edge point of the box.
      */
    Vector3 getBoxMin() const {return boxmin;}

    /**
      *@returns Maximum edge point of the box.
      */
    Vector3 getBoxMax() const {return boxmax;}

    /**Translate the box.
      *@param v translation Vector
      */
    void translate(const Vector3& v) {boxmin.add(v); boxmax.add(v);}

    /**Scale the box.
      *@param v scaling Vector v
      */
    void scale(const Vector3& v);

    /**Rotate the box.
      *@param rotationMatrix Matrix which describes the rotation
      */
    void rotate(const Matrix& rotationMatrix);

    /**Transformate the box the same way as the given Transformatable.
      *@param t the Transformatable
      */        
    void transformate(const Transformatable &t);

    /**Intersect Box with Ray.
      *@param r the Ray
      *@returns -1 if no intersection, INTERSECTION_TIME_EPSILON if Ray's origin is inside the box.
      */
    DBL intersect(const Ray &r) const;
    
    /**Intersect Box with Ray limited to maximum time.
      *@param r the Ray
      *@param tmax Maximum intersection time.
      *@returns -1 if no intersection, INTERSECTION_TIME_EPSILON if Ray's origin is inside the box.
      */
    DBL intersect(const Ray &r, DBL tmax) const;

    /**Test point for box insidness.
      *@param a the point
      *@returns true if the point is inside the box else false
      */
    bool isInsideAt(const Vector3& a) const;

private: // Static members

    /**Intersection statistics.
      */
    static HitStatistics stat;
    
private: // Private attributes
    /**stores minimum edge
      */
    Vector3 boxmin;
    /**stores maximal edge
      */
    Vector3 boxmax;

private: // Private methods
    void updateBoundingBoxPoints(Vector3& min, Vector3& max, const Matrix& rot, Vector3 test);

};

#endif