cpp-philosophy-1

cpp-philosophy-1.cpp

// --------------------------------------------------------
// Both are the same functions, with two different designs.
// --------------------------------------------------------



//! Compute gravitational acceleration.
/**
 *
 * @param GM gravitational parameter of body exerting acceleration
 * @param r1 position of body exerting acceleration
 * @param r2 position of body subject acceleration
 *
 * @return acceleration exerted on second body  
 */
Eigen::Vector3d pointMassAcceleration(
    const double GM,
    const Eigen::Vector3d& r1 
    const Eigen::Vector3d& r2)
{
    // d:  distance between bodies
    double d = ( r2 - r1 ).norm( );
    return - G * ( r2 - r1 ) / ( d * d * d );
}


// --------------------------------------------------------


//! Compute gravitational acceleration.
Eigen::Vector3d computeGravitationalAcceleration(
        const Eigen::Vector3d& positionOfBodySubjectToAcceleration,
        const double gravitationalParameterOfBodyExertingAcceleration,
        const Eigen::Vector3d& positionOfBodyExertingAcceleration )
{
    double distance = ( positionOfBodySubjectToAcceleration - positionOfBodyExertingAcceleration ).norm( );
    return -gravitationalParameterOfBodyExertingAcceleration
            * ( positionOfBodySubjectToAcceleration - positionOfBodyExertingAcceleration )
            / ( distance * distance * distance );
}

// --------------------------------------------------------
//
// Points to consider:
// - readability
// - maintainability
// - intuitiveness