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vector3d.cc

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/*
  svas_server -- virtual World Server of Svas
  Copyright (c) 2001, 2002 David Moreno Montero
 
 
  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.
 
  This program is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.
 
  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  02111-1307, USA.  

*/

#include <math.h>
#include "vector3d.h"
#include <stdio.h>
#include "quaternion.h"

extern "C"{
  double cos(double);
  double sin(double);
};



inline Vector3d::Vector3d(double _x, double _y, double _z){
  x=_x;
  y=_y;
  z=_z;
}

inline string Vector3d::toString(void){
  char str[256];

  sprintf(str, "(%g,%g,%g)",x,y,z);

  return string(str);
}




inline Vector3d Vector3d::operator=(const Vector3d &b){
  x=b.x;  y=b.y;  z=b.z;
  return *this;
}

inline Vector3d Vector3d::operator+=(const Vector3d &v){
  x+=v.x; y+=v.y; z+=v.z;
  return *this;
}

inline Vector3d Vector3d::operator-=(const Vector3d &v){
  x-=v.x; y-=v.y; z-=v.z;
  return *this;
}

inline Vector3d Vector3d::operator*=(double d){
  x*=d; y*=d; z*=d;
  return *this;
}

inline Vector3d Vector3d::operator/=(double d){
  x/=d; y/=d; z/=d;
  return *this;
}



inline double Vector3d::module(void){
  return sqrt(x*x+y*y+z*z);
}

inline Vector3d Vector3d::normalized(void){
  double m=module();
  return Vector3d(x/m,y/m,z/m);
}

inline void Vector3d::normalize(void){
  double m=module();
  x/=m;
  y/=m;
  z/=m;
}

/**
 * Rotates current vector over a given axis, a given ammount. The
 * formula used is a solved version of quaternion rotations.
 */
inline Vector3d Vector3d::rotate(const Vector3d &v, double ang){
  // First we calculate [w,x,y,z], the rotation quaternion
  double w,x,y,z;
  Vector3d V=v;
  V.normalize();
  w=cos(-ang/2);  // The formula rotates counterclockwise, and I
                  // prefer clockwise, so I change 'ang' sign
  double s=sin(-ang/2);
  x=V.x*s;
  y=V.y*s;
  z=V.z*s;
  // now we calculate [w^2, x^2, y^2, z^2]; we need it
  double w2=w*w;
  double x2=x*x;
  double y2=y*y;
  double z2=z*z;
  
  // And apply the formula
  return Vector3d((*this).x*(w2+x2-y2-z2) + (*this).y*2*(x*y+w*z)   + (*this).z*2*(x*z-w*y),
          (*this).x*2*(x*y-w*z)   + (*this).y*(w2-x2+y2-z2) + (*this).z*2*(y*z+w*x),
          (*this).x*2*(x*z+w*y)   + (*this).y*2*(y*z-w*x)   + (*this).z*(w2-x2-y2+z2));
}


inline double Vector3d::X(){
  return x;
}

inline double Vector3d::Y(){
  return y;
}

inline double Vector3d::Z(){
  return z;
}

inline double Vector3d::distToPlane(const Point3d &p, const Vector3d &n){
  Vector3d N=n;
  N.normalize();

  return fabs(N*(*this-p));
}


inline double Vector3d::distToLine(const Point3d &p, const Vector3d &d){
  Vector3d v=(*this-p);
  Vector3d D=d;
  return (D^v).module()/D.module();
}


//// These operators are just friends to facilitate the use with const&

inline bool operator==(const Vector3d &a,const Vector3d &b){
  return  (a.x==b.x)&&(a.y==b.y)&&(a.z==b.z);
}


inline double operator*(const Vector3d &a,const Vector3d &b){
  return a.x*b.x + a.y*b.y + a.z*b.z;
}

inline Vector3d operator^(const Vector3d &a,const Vector3d &b){
  return Vector3d(a.y*b.z-a.z*b.y,
          -a.x*b.z+a.z*b.x,
          a.x*b.y-a.y*b.x);
}

inline Vector3d operator+(const Vector3d &a,const Vector3d &b){
  return Vector3d(a.x+b.x, a.y+b.y, a.z+b.z);
}

inline Vector3d operator-(const Vector3d &a,const Vector3d &b){
  return Vector3d(a.x-b.x, a.y-b.y, a.z-b.z);
}

inline Vector3d operator-(const Vector3d &a){
  return Vector3d(-a.x, -a.y, -a.z);
}

inline Vector3d operator*(const Vector3d &a,double d){
  return Vector3d(a.x*d, a.y*d, a.z*d);
}

inline Vector3d operator/(const Vector3d &a, double d){
  return Vector3d(a.x/d, a.y/d, a.z/d);
}
inline Vector3d operator*(double d,const Vector3d &a){
  return Vector3d(a.x*d, a.y*d, a.z*d);
}

inline Vector3d operator/(double d,const Vector3d &a){
  return Vector3d(a.x/d, a.y/d, a.z/d);
}


inline Vector3d Vector3d::operator=(const Quaternion &_q){
  Quaternion q(_q);
  *this=q.getAxis();
  return *this;
}

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