forcefield_element.h

// -*-c++-*-
#ifndef STORMM_FORCEFIELD_ELEMENT_H
#define STORMM_FORCEFIELD_ELEMENT_H
 
#include <vector>
#include "copyright.h"
#include "Constants/behavior.h"
#include "DataTypes/stormm_vector_types.h"
#include "Topology/atomgraph.h"
#include "Topology/atomgraph_enumerators.h"
#include "forcefield_enumerators.h"
 
namespace stormm {
namespace modeling {
 
using constants::ExceptionResponse;
using topology::AtomGraph;
using topology::TorsionKind;
using topology::VirtualSiteKind;

class ForceFieldElement {
public:

  ForceFieldElement(ParameterKind kind_in = ParameterKind::NONE);
  
  ForceFieldElement(ParameterKind kind_in, char4 atom_i_in);
 
  ForceFieldElement(ParameterKind kind_in, char4 atom_i_in, char4 atom_j_in);
 
  ForceFieldElement(ParameterKind kind_in, char4 atom_i_in, char4 atom_j_in, char4 atom_k_in);
 
  ForceFieldElement(ParameterKind kind_in, char4 atom_i_in, char4 atom_j_in, char4 atom_k_in,
                    char4 atom_l_in, TorsionKind tkind_in = TorsionKind::PROPER);
 
  ForceFieldElement(ParameterKind kind_in, VirtualSiteKind frame_type_in, char4 atom_i_in,
                    char4 atom_j_in, char4 atom_k_in, char4 residue_i_in, char4 residue_j_in,
                    char4 residue_k_in);
 
  ForceFieldElement(ParameterKind kind_in, VirtualSiteKind frame_type_in, char4 atom_i_in,
                    char4 atom_j_in, char4 atom_k_in, char4 atom_l_in, char4 residue_i_in,
                    char4 residue_j_in, char4 residue_k_in, char4 residue_l_in);
 
  ForceFieldElement(ParameterKind kind_in, VirtualSiteKind frame_type_in, char4 atom_i_in,
                    char4 atom_j_in, char4 atom_k_in, char4 atom_l_in, char4 atom_m_in,
                    char4 residue_i_in, char4 residue_j_in, char4 residue_k_in, char4 residue_l_in,
                    char4 residue_m_in);
 
  ForceFieldElement(ParameterKind kind_in, char4 atom_i_in, char4 atom_j_in, char4 atom_k_in,
                    char4 atom_l_in, char4 atom_m_in, char4 residue_i_in, char4 residue_j_in,
                    char4 residue_k_in, char4 residue_l_in, char4 residue_m_in,
                    const std::vector<double> &surface_in, const std::vector<int2> &locations_in);

  ParameterKind getKind() const;
  
  char4 getNameOfAtom(char atom_rank = 'I') const;
  
  char4 getTypeOfAtom(char atom_rank = 'I') const;
    
  char4 getNameOfResidue(char atom_rank = 'I') const;

  double getCharge() const;

  double getSigma() const;

  double getEpsilon() const;

  double getRho() const;

  double getStiffnessConstant() const;

  double getEquilibriumConstant() const;

  double getAmplitude() const;

  double getPhaseAngle() const;

  double getPeriodicity() const;

  double getElectrostaticScaling() const;
  
  double getVanDerWaalsScaling() const;

  TorsionKind getTorsionKind() const;
  
  std::vector<double> getSurfaceValues() const;
  
  std::vector<int2> getSurfaceIndices() const;  
  
  VirtualSiteKind getVirtualSiteFrameType() const;

  bool testSigmaModification() const;
  
  bool testEpsilonModification() const;

  bool testRhoModification() const;

  bool testStiffnessModification() const;

  bool testEquilibriumModification() const;

  bool testAmplitudeModification() const;

  bool testPhaseAngleModification() const;

  bool testPeriodicityModification() const;
  
  void setStiffness(double stiffness_in);

  void setEquilibrium(double equilbrium_in);

  void setPhaseAngle(double phase_angle_in);

  void setAmplitude(double amplitude_in);

  void setPeriodicity(double periodicity_in);

  void setChargeScaling(double scaling_in);

  void setVanDerWaalsScaling(double scaling_in);

  void setCharge(double charge_in);

  void setSigma(double sigma_in);
  
  void setEpsilon(double epsilon_in);
  
  void setRho(double rho_in);

  void apply(AtomGraph *ag, ExceptionResponse policy = ExceptionResponse::SILENT) const;
  
private:
  ParameterKind kind;    
  char4 atom_name_i;     
  char4 atom_name_j;     
  char4 atom_name_k;     
  char4 atom_name_l;     
  char4 atom_name_m;     
  char4 residue_name_i;  
  char4 residue_name_j;  
  char4 residue_name_k;  
  char4 residue_name_l;  
  char4 residue_name_m;  
 
  // General-purpose real-values numbers for keeping this parameter's details.  The information in
  // any of these parameters is optional in the namelist, but it may be necessary to specify at
  // least one in order to alter anything about a parameter.  Each of these properties begins with
  // its "activation" set to false, and the flag must be set, post-construction, in order to show
  // that one of the properties was specified by the user.
  double property_a;  
  double property_b;  
  double property_c;  
  bool activate_a;    
  bool activate_b;    
  bool activate_c;    
  
  
  // Miscellaneous properties
  TorsionKind torsion_kind;     
  std::vector<double> surface;  
  std::vector<int2> locations;  
  VirtualSiteKind frame_type;   
};
  
} // namespace modeling
} // namespace stormm
 
#endif