CartVect.hpp

Go to the documentation of this file.

#ifndef MB_CART_VECT_HPP
#define MB_CART_VECT_HPP
 
#include <cmath>
#include <iosfwd>
#include <cfloat>
 
namespace moab
{
 
/**
 * \brief Cartesian Vector
 */
class CartVect
{
 private:
 double d[3];
 
 public:
 inline CartVect() {}
 /**Initialze all three values to same scalar (typically zero)*/
 explicit inline CartVect( double v )
 {
 d[0] = d[1] = d[2] = v;
 }
 inline CartVect( double i, double j, double k )
 {
 d[0] = i;
 d[1] = j;
 d[2] = k;
 }
 /**Initialze from array*/
 explicit inline CartVect( const double a[3] )
 {
 d[0] = a[0];
 d[1] = a[1];
 d[2] = a[2];
 }
 inline CartVect& operator=( const double v[3] )
 {
 d[0] = v[0];
 d[1] = v[1];
 d[2] = v[2];
 return *this;
 }
 
 inline double& operator[]( unsigned i )
 {
 return d[i];
 }
 inline double operator[]( unsigned i ) const
 {
 return d[i];
 }
 
 inline CartVect& operator+=( const CartVect& v )
 {
 d[0] += v.d[0];
 d[1] += v.d[1];
 d[2] += v.d[2];
 return *this;
 }
 inline CartVect& operator-=( const CartVect& v )
 {
 d[0] -= v.d[0];
 d[1] -= v.d[1];
 d[2] -= v.d[2];
 return *this;
 }
 /** Assign cross product to this */
 inline CartVect& operator*=( const CartVect& v );
 
 inline CartVect& operator+=( double s )
 {
 d[0] += s;
 d[1] += s;
 d[2] += s;
 return *this;
 }
 inline CartVect& operator-=( double s )
 {
 d[0] -= s;
 d[1] -= s;
 d[2] -= s;
 return *this;
 }
 inline CartVect& operator*=( double s )
 {
 d[0] *= s;
 d[1] *= s;
 d[2] *= s;
 return *this;
 }
 inline CartVect& operator/=( double s )
 {
 d[0] /= s;
 d[1] /= s;
 d[2] /= s;
 return *this;
 }
 inline bool operator==( const CartVect& v ) const
 {
 return d[0] == v[0] && d[1] == v[1] && d[2] == v[2];
 }
 inline bool operator==( double val ) const
 {
 return d[0] == val && d[1] == val && d[2] == val;
 }
 
 inline double length() const; //!< vector length
 
 inline double length_squared() const;
 
 inline void normalize(); //!< make unit length, or 0 if length < DBL_MIN
 
 inline void flip(); //!< flip direction
 
 /** per-element scalar multiply (this[0] *= v[0], this[1] *= v[1], ...) */
 inline void scale( const CartVect& v )
 {
 d[0] *= v.d[0];
 d[1] *= v.d[1];
 d[2] *= v.d[2];
 }
 
 // get pointer to array of three doubles
 inline double* array()
 {
 return d;
 }
 inline const double* array() const
 {
 return d;
 }
 
 /** initialize double array from this */
 inline void get( double v[3] ) const
 {
 v[0] = d[0];
 v[1] = d[1];
 v[2] = d[2];
 }
 
 /** initialize float array from this */
 inline void get( float v[3] ) const
 {
 v[0] = static_cast< float >( d[0] );
 v[1] = static_cast< float >( d[1] );
 v[2] = static_cast< float >( d[2] );
 }
};
 
inline CartVect operator+( const CartVect& u, const CartVect& v )
{
 return CartVect( u[0] + v[0], u[1] + v[1], u[2] + v[2] );
}
 
inline CartVect operator-( const CartVect& u, const CartVect& v )
{
 return CartVect( u[0] - v[0], u[1] - v[1], u[2] - v[2] );
}
 
/** cross product */
inline CartVect operator*( const CartVect& u, const CartVect& v )
{
 return CartVect( u[1] * v[2] - u[2] * v[1], u[2] * v[0] - u[0] * v[2], u[0] * v[1] - u[1] * v[0] );
}
 
//! Dot product
inline double operator%( const CartVect& u, const CartVect& v )
{
 return u[0] * v[0] + u[1] * v[1] + u[2] * v[2];
}
 
inline CartVect& CartVect::operator*=( const CartVect& v )
{
 return *this = *this * v;
}
 
inline double CartVect::length() const
{
 return std::sqrt( *this % *this );
}
 
inline double CartVect::length_squared() const
{
 return d[0] * d[0] + d[1] * d[1] + d[2] * d[2];
}
 
inline void CartVect::normalize()
{
 double tmp = length();
 if( tmp < DBL_MIN )
 d[0] = d[1] = d[2] = 0;
 else
 *this /= tmp;
}
 
inline void CartVect::flip()
{
 d[0] = -d[0];
 d[1] = -d[1];
 d[2] = -d[2];
}
 
//! Interior angle between two vectors
inline double angle( const CartVect& u, const CartVect& v )
{
 double tmp = ( u % v ) / std::sqrt( ( u % u ) * ( v % v ) );
 if( tmp > 1. ) tmp = 1.;
 if( tmp < -1. ) tmp = -1.;
 return std::acos( tmp );
}
 
//! Interior angle between two vectors
inline double angle_robust( CartVect u, CartVect v )
{
 u.normalize();
 v.normalize();
 
 double tmp = ( u % v ) ;
 if( tmp - 1. >= - 1.e-12 )
 {
 double dist = (u - v).length();
 return dist; // approximate sin(x) with x for very small dist
 }
 
 if( tmp < -1. ) tmp = -1.;
 return std::acos( tmp );
}
 
inline CartVect operator-( const CartVect& v )
{
 return CartVect( -v[0], -v[1], -v[2] );
}
inline CartVect operator+( const CartVect& v, double s )
{
 return CartVect( v[0] + s, v[1] + s, v[2] + s );
}
inline CartVect operator-( const CartVect& v, double s )
{
 return CartVect( v[0] - s, v[1] - s, v[2] - s );
}
inline CartVect operator*( const CartVect& v, double s )
{
 return CartVect( v[0] * s, v[1] * s, v[2] * s );
}
inline CartVect operator/( const CartVect& v, double s )
{
 return CartVect( v[0] / s, v[1] / s, v[2] / s );
}
inline CartVect operator+( double s, const CartVect& v )
{
 return CartVect( v[0] + s, v[1] + s, v[2] + s );
}
inline CartVect operator-( double s, const CartVect& v )
{
 return CartVect( v[0] - s, v[1] - s, v[2] - s );
}
inline CartVect operator*( double s, const CartVect& v )
{
 return CartVect( v[0] * s, v[1] * s, v[2] * s );
}
 
//! Get unit vector in same direction
inline CartVect unit( const CartVect& v )
{
 const double len = v.length();
 return CartVect( v[0] / len, v[1] / len, v[2] / len );
}
 
std::ostream& operator<<( std::ostream& s, const CartVect& v );
 
} // namespace moab
 
#endif