colvaratoms.h

// -*- c++ -*-

#ifndef COLVARATOMS_H
#define COLVARATOMS_H

#include "colvarmodule.h"
#include "colvarparse.h"
#include "colvardeps.h"



class colvarmodule::atom {

protected:

  int index;

public:

  int             id;

  cvm::real       mass;

  cvm::real       charge;

  cvm::atom_pos   pos;

  cvm::rvector    vel;

  cvm::rvector    total_force;

  cvm::rvector   grad;

  atom();

  atom(int atom_number);

  atom(cvm::residue_id const &residue,
       std::string const     &atom_name,
       std::string const     &segment_id);

  atom(atom const &a);

  ~atom();

  inline void reset_data()
  {
    pos = cvm::atom_pos(0.0);
    vel = grad = total_force = cvm::rvector(0.0);
  }

  inline void update_mass()
  {
    mass = (cvm::proxy)->get_atom_mass(index);
  }

  inline void update_charge()
  {
    charge = (cvm::proxy)->get_atom_charge(index);
  }

  inline void read_position()
  {
    pos = (cvm::proxy)->get_atom_position(index);
  }

  inline void read_velocity()
  {
    vel = (cvm::proxy)->get_atom_velocity(index);
  }

  inline void read_total_force()
  {
    total_force = (cvm::proxy)->get_atom_total_force(index);
  }

  inline void apply_force(cvm::rvector const &new_force) const
  {
    (cvm::proxy)->apply_atom_force(index, new_force);
  }
};



class colvarmodule::atom_group
  : public colvarparse, public colvardeps
{
public:

  atom_group(std::string const &conf,
             char const        *key);

  // TODO Make this field part of the data structures that link a group to a CVC
  std::string key;

  int init();

  int setup();

  int parse(std::string const &conf);

  int add_atom_numbers(std::string const &numbers_conf);
  int add_index_group(std::string const &index_group_name);
  int add_atom_numbers_range(std::string const &range_conf);
  int add_atom_name_residue_range(std::string const &psf_segid,
                                  std::string const &range_conf);
  int parse_fitting_options(std::string const &group_conf);

  atom_group(std::vector<cvm::atom> const &atoms_in);

  int add_atom(cvm::atom const &a);

  int add_atom_id(int aid);

  int remove_atom(cvm::atom_iter ai);

  void reset_mass(std::string &name, int i, int j);

  static std::vector<feature *> ag_features;

  virtual std::vector<feature *> &features() {
    return ag_features;
  }

  atom_group();

  ~atom_group();

protected:

  std::vector<cvm::atom> atoms;

  std::vector<int> atoms_ids;

  cvm::atom_pos dummy_atom_pos;

  int index;

public:

  inline cvm::atom & operator [] (size_t const i)
  {
    return atoms[i];
  }

  inline cvm::atom const & operator [] (size_t const i) const
  {
    return atoms[i];
  }

  inline cvm::atom_iter begin()
  {
    return atoms.begin();
  }

  inline cvm::atom_const_iter begin() const
  {
    return atoms.begin();
  }

  inline cvm::atom_iter end()
  {
    return atoms.end();
  }

  inline cvm::atom_const_iter end() const
  {
    return atoms.end();
  }

  inline size_t size() const
  {
    return atoms.size();
  }

  std::string const print_atom_ids() const;

  bool b_dummy;

  std::vector<int> sorted_ids;

  int create_sorted_ids(void);

  bool b_center;

  bool b_rotate;
  cvm::rotation rot;

  bool b_user_defined_fit;

  bool b_fit_gradients;

  std::vector<cvm::atom_pos> ref_pos;

  cvm::atom_pos              ref_pos_cog;

  atom_group                *fitting_group;

  cvm::real total_mass;
  void update_total_mass();

  cvm::real total_charge;
  void update_total_charge();

  bool        noforce;

  void read_positions();

  void calc_apply_roto_translation();

  void center_ref_pos();

  void apply_translation(cvm::rvector const &t);

  void read_velocities();

  void read_total_forces();

  inline void reset_atoms_data()
  {
    for (cvm::atom_iter ai = atoms.begin(); ai != atoms.end(); ai++)
      ai->reset_data();
    if (fitting_group)
      fitting_group->reset_atoms_data();
  }

  int calc_required_properties();

  std::vector<cvm::atom_pos> positions() const;

  int calc_center_of_geometry();

private:

  cvm::atom_pos cog;

  cvm::atom_pos cog_orig;

public:

  inline cvm::atom_pos center_of_geometry() const
  {
    return cog;
  }

  int calc_center_of_mass();
private:
  cvm::atom_pos com;
  // TODO for scalable calculations of more complex variables (e.g. rotation),
  // use a colvarvalue of vectors to hold the entire derivative
  cvm::rvector scalar_com_gradient;
public:
  inline cvm::atom_pos center_of_mass() const
  {
    return com;
  }

  std::vector<cvm::atom_pos> positions_shifted(cvm::rvector const &shift) const;

  std::vector<cvm::rvector> velocities() const;

  int calc_dipole(cvm::atom_pos const &com);
private:
  cvm::rvector dip;
public:
  inline cvm::rvector dipole() const
  {
    return dip;
  }

  std::vector<cvm::rvector> total_forces() const;

  cvm::rvector total_force() const;


  void set_weighted_gradient(cvm::rvector const &grad);

  void calc_fit_gradients();

  std::vector<cvm::atom_pos> fit_gradients;

  void apply_colvar_force(cvm::real const &force);

  void apply_force(cvm::rvector const &force);

};


#endif