sphere.h

游戏编程精粹2第四章源码

/* Copyright (C) John W. Ratcliff, 2001. 
 * All rights reserved worldwide.
 *
 * This software is provided "as is" without express or implied
 * warranties. You may freely copy and compile this source into
 * applications you distribute provided that the copyright text
 * below is included in the resulting source code, for example:
 * "Portions Copyright (C) John W. Ratcliff, 2001"
 */
#ifndef SPHERE_H

#define SPHERE_H

#include "vector.h"


/***********************************************************************/
/** SPHERE.H    : Base class to represent a Sphere in 3 space.         */
/**                                                                    */
/**               Written by John W. Ratcliff [e-mail]        */
/***********************************************************************/

class SphereInterface
{
public:
  virtual int GetVertexCount(void) const = 0;
  virtual bool GetVertex(int i,Vector3d<float> &vect) const = 0;
private:
};



class Sphere
{
public:
	Sphere();

 	Sphere(const Vector3d<float> &center, float radius);
	Set(const Vector3d<float> &center, float radius);

  void Compute(const SphereInterface &source);

  float GetRadius(void) const { return mRadius; };
  float GetRadius2(void) const { return mRadius2; };
  const Vector3d<float>& GetCenter(void) const { return mCenter; };

  bool RayIntersection(const Vector3d<float> &rayOrigin,
	 				   const Vector3d<float> &V,
					   float distance,
					   Vector3d<float> *intersect);


	bool RayIntersection(const Vector3d<float> &rayOrigin,
											 const Vector3d<float> &rayDirection,
											 Vector3d<float> *intersect);

	bool RayIntersectionInFront(const Vector3d<float> &rayOrigin,
															const Vector3d<float> &rayDirection,
															Vector3d<float> *intersect);

  void Report(void);

  void SetRadius(float radius)
  {
    mRadius = radius;
    mRadius2 = radius*radius;
  }


  bool InSphereXY(const Vector3d<float> &pos,float distance) const
  {
    float dx = pos.x - mCenter.x;
    float dy = pos.y - mCenter.y;
    float dist  = sqrtf( dx*dx + dy*dy );
    if ( dist < (mRadius+distance) ) return true;
    return false;
  };

  bool InSphere(const Vector3d<float> &pos,float distance) const
  {
    float dx = pos.x - mCenter.x;
    float dy = pos.y - mCenter.y;
    float dz = pos.z - mCenter.z;

    float dist  = sqrtf( dx*dx + dy*dy + dz*dz );
    if ( dist < (mRadius+distance) ) return true;
    return false;
  }



protected:
  Vector3d<float> mCenter;
private:
  float        mRadius;
  float        mRadius2; // radius squared.
};


inline Sphere::Sphere()
: mCenter(Vector3d<float>(0.0f, 0.0f, 0.0f)), mRadius(0.0f), mRadius2(0.0f) { };

inline Sphere::Sphere(const Vector3d<float> &center, float radius)
: mCenter(center), mRadius(radius), mRadius2(radius*radius) { };

#endif