Environment.h

#ifndef PRDC_ENVIRONMENT_H
#define PRDC_ENVIRONMENT_H
 
/*
* PSCF - Polymer Self-Consistent Field
*
* Copyright 2015 - 2025, The Regents of the University of Minnesota
* Distributed under the terms of the GNU General Public License.
*/
 
#include <prdc/solvers/MixtureReal.h>         // method parameter
#include <pscf/environment/EnvironmentBase.h> // base class
#include <util/containers/FSArray.h>          // container
#include <iostream>
 
namespace Pscf {
namespace Prdc {
 
   using namespace Util;

   class Environment : public EnvironmentBase
   {
 
   public:

      Environment();

      ~Environment();

      void reset();

      template <int D, class PT, class ST>
      void computeStress(MixtureReal<D, PT, ST> const & mixture, 
                         FSArray<bool, 6> const & flexibleParams);

      virtual double modifyStress(int paramId, double stress) const;
      
      double stress(int paramId) const;

      void writeStress(std::ostream& out) const;

      bool hasStress() const;

      void setNParams(int nParams);
 
   private: 

      FSArray<double, 6> stress_;

      FSArray<int, 6> stressIds_;

      bool hasStress_;

      int nParam_;
      
   };
 
   /*
   * Compute and store the environment-modified SCFT stress.
   * 
   * (Note: this definition is included in header file so that it can 
   * be implicitly instantiated by the compiler wherever needed)
   */
   template <int D, class PT, class ST>
   void Environment::computeStress(MixtureReal<D, PT, ST> const & mixture, 
                                   FSArray<bool, 6> const & flexibleParams)
   {
      if (hasStress_) return;
 
      UTIL_CHECK(!EnvironmentBase::needsUpdate());
      UTIL_CHECK(mixture.hasStress());
      UTIL_CHECK(nParam_ > 0);
      UTIL_CHECK(stress_.size() == 0);
      UTIL_CHECK(stressIds_.size() == 0);
 
      double stress;
      for (int i = 0; i < nParam_; ++i) {
         if (flexibleParams[i]) {
            // First, retrieve stress contribution from Mixture
            stress = mixture.stress(i);
 
            // Next, allow Environment to modify stress using virtual
            // modifyStress method (defined by subclasses)
            stress = modifyStress(i, stress);
 
            // Store stress and its index
            stress_.append(stress);
            stressIds_.append(i);
         }
      }
 
      hasStress_ = true;
   }
 
} // namespace Prdc
} // namespace Pscf
#endif