File indexing completed on 2024-04-21 03:51:21

 /*
     SPDX-FileCopyrightText: 2007 Vladimir Kuznetsov <ks.vladimir@gmail.com>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 
 /** \file coulombforce.h
  *  \brief CoulombForce class
  */
 
 #ifndef STEPCORE_COULOMBFORCE_H
 #define STEPCORE_COULOMBFORCE_H
 
 #include "force.h"
 #include "object.h"
 #include "objecterrors.h"
 #include "constants.h"
 
 namespace StepCore
 {
 
 class CoulombForce;
 
 /** \ingroup errors
  *  \brief Errors object for CoulombForce
  */
 class CoulombForceErrors: public ObjectErrors
 {
     STEPCORE_OBJECT(CoulombForceErrors)
 
 public:
     /** Constructs CoulombForceErrors */
     explicit CoulombForceErrors(Item* owner = nullptr)
         : ObjectErrors(owner), _coulombConstVariance(0) {}
 
     /** Get owner as CoulombForce */
     CoulombForce* coulombForce() const;
 
     /** Get coulombConst variance */
     double coulombConstVariance() const { return _coulombConstVariance; }
     /** Set coulombConst variance */
     void   setCoulombConstVariance(double coulombConstVariance) {
         _coulombConstVariance = coulombConstVariance; }
 
 protected:
     double _coulombConstVariance;
     friend class CoulombForce;
 };
 
 
 /** \ingroup forces
  *  \brief Coulomb electrostatic force.
  *
  *  The force acts between pairs of charged bodies (currently only
  *  ChargedParticle) and equals:
  *  \f[
  *      \overrightarrow{f} = k_C
  *                           \frac{q_1 q_2 \overrightarrow{r}}
  *                                  {|\overrightarrow{r}|^3}
  *  \f]
  *  where:\n
  *  \f$k_C\f$ is CoulombForce::coulombConst\n
  *  \f$q_1\f$ and \f$q_2\f$ is ChargedParticle::charge of the first
  *  and second body\n
  *  \f$\overrightarrow{r}\f$ is difference of Particle::position
  *  of the first and second body
  *
  *  \todo Add interface for charged bodies, support bodies with
  *        distributed charge
  */
 class CoulombForce : public Force
 {
     STEPCORE_OBJECT(CoulombForce)
 
 public:
     /** Constructs CoulombForce */
     explicit CoulombForce(double coulombConst = Constants::Coulomb);
 
     void calcForce(bool calcVariances) override;
 
     /** Get coulomb const */
     double coulombConst() const { return _coulombConst; }
     /** Set coulomb const */
     void   setCoulombConst(double coulombConst) { _coulombConst = coulombConst; }
 
     /** Get (and possibly create) CoulombForceErrors object */
     CoulombForceErrors* coulombForceErrors() {
         return static_cast<CoulombForceErrors*>(objectErrors()); }
 
 protected:
     ObjectErrors* createObjectErrors() override { return new CoulombForceErrors(this); }
 
     double _coulombConst;
 };
 
 } // namespace StepCore
 
 #endif