Exemplo n.º 1
0
// Spherical linear interpolation between direction vectors.
// Intermediate vectors follow great circle path with constant velocity.
vec3d slerp( const vec3d& a, const vec3d& b, const double &t )
{
    vec3d an = a / a.mag();
    vec3d bn = b / b.mag();

    double dp = dot( an, bn );

    double theta = 0.0;
    if ( dp >= -1.0 && dp <= 1.0 )
    {
        theta = acos( dp );
    }

    // Initialize retvec as a-direction.
    vec3d retvec = an;

    // If vectors are not parallel, interpolate between them.
    if ( std::abs( theta ) > 1.0e-6 )
    {
        // Drop division by sin(theta) because .normalize() will scale
        double coeff1 = sin( ( 1.0 - t ) * theta );  // implied  / sin(theta)
        double coeff2 = sin( t * theta );            // implied  / sin(theta)

        retvec = coeff1 * an + coeff2 * bn;
        retvec.normalize();
    }

    return retvec;
}
Exemplo n.º 2
0
//******* Angle Between Vectors ******//
double angle(const vec3d& a, const vec3d& b)
{
   double angle = dot(a, b)/(a.mag()*b.mag());

   if ( angle < -1.0 )			angle = -1.0;
   else if ( angle > 1.0 )		angle = 1.0;

   return(acos(angle));

 }
Exemplo n.º 3
0
//******* Cosine of Angle Between Vectors ******//
double cos_angle(const vec3d& a, const vec3d& b)
{
   double angle = dot(a, b)/(a.mag()*b.mag());

   if (angle < -1.0 )
	   return -1.0;
   else if ( angle > 1.0)
	   return 1.0;

   return angle;
}
Exemplo n.º 4
0
//******* Angle Between Vectors ******//
double angle( const vec3d& a, const vec3d& b )
{
    double angle = dot( a, b ) / ( a.mag() * b.mag() );

    if ( angle >= -1.0 && angle <= 1.0 )
    {
        return( acos( angle ) );
    }
    else
    {
        return( 0.0 );
    }
}
Exemplo n.º 5
0
//to return projection vector
vec3d vec3d :: proj(const vec3d& vec) const
{
	float m = vec.mag();
	if(m == 0)
		throw "invalid vector";
	return vec.unit()*(operator*(vec)/m);
}
Exemplo n.º 6
0
//to return the angle between vectors in radians
double vec3d :: angle(const vec3d& vec) const
{
	float this_mag = mag();
	float vec_mag = vec.mag();
	if(this_mag == 0 || vec_mag == 0)
		throw "invalid vector";
	return acos(operator*(vec)/(this_mag*vec_mag));
}