source: orxonox.OLD/orxonox/branches/chris/core/vector.cc @ 1939

/* 
   orxonox - the future of 3D-vertical-scrollers

   Copyright (C) 2004 orx

   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, or (at your option)
   any later version.

   ### File Specific:
   main-programmer: Christian Meyer
   co-programmer: ...
*/


#include "vector.h"


using namespace std;

/**
   \brief add two vectors
   \param v: the other vector
*/
Vector Vector::operator+ (const Vector& v) const
{
  Vector r;
  
  r.x = x + v.x;
  r.y = y + v.y;
  r.z = z + v.z;
  
  return r;
}

/**
   \brief subtract a vector from another
   \param v: the other vector
*/
Vector Vector::operator- (const Vector& v) const
{
  Vector r;
  
  r.x = x - v.x;
  r.y = y - v.y;
  r.z = z - v.z;
  
  return r;
}

/**
   \brief calculate the dot product of two vectors
   \param v: the other vector
*/
float Vector::operator* (const Vector& v) const
{
  return x*v.x+y*v.y+z*v.z;
}

/**
   \brief multiply a vector with a float
   \param v: the factor
*/
Vector Vector::operator* (float f) const
{  
  Vector r;
  
  r.x = x * f;
  r.y = y * f;
  r.z = z * f;
  
  return r;
}

/**
   \brief divide a vector with a float
   \param v: the factor
*/
Vector Vector::operator/ (float f) const
{
  Vector r;
  
  if( f == 0.0)
  {
    // Prevent divide by zero
    return Vector (0,0,0);
  }
  
  r.x = x / f;
  r.y = y / f;
  r.z = z / f;
  
  return r;
}

/**
   \brief calculate the dot product of two vectors
   \param v: the other vector
*/
float Vector::dot (const Vector& v) const
{
  return x*v.x+y*v.y+z*v.z;
}

/**
   \brief calculate the cross product of two vectors
   \param v: the other vector
*/
Vector Vector::cross (const Vector& v) const
{
  Vector r;
  
  r.x = y * v.z - z * v.y;
  r.y = z * v.x - x * v.z;
  r.z = x * v.y - y * v.x;
  
  return r;
}
  
/**
   \brief normalize the vector to lenght 1.0
*/
void Vector::normalize ()
{
  float l = len();
  
  if( l == 0.0)
  {
    // Prevent divide by zero
    return;
  }
  
  x = x / l;
  y = y / l;
  z = z / l;
}
 
/**
   \brief calculate the lenght of the vector
*/
float Vector::len () const
{
  return sqrt (x*x+y*y+z*z);
}

/**
   \brief calculate the angle between two vectors in radiances
   \param v1: a vector
   \param v2: another vector
*/
float angle_rad (const Vector& v1, const Vector& v2)
{
  return acos( v1 * v2 / (v1.len() * v2.len()));
}

/**
   \brief calculate the angle between two vectors in degrees
   \param v1: a vector
   \param v2: another vector
*/
float angle_deg (const Vector& v1, const Vector& v2)
{
  float f;
  f = acos( v1 * v2 / (v1.len() * v2.len()));
  return f * 180 / PI;
}