Rewrite BMHTF interaction interface

src/core/nonbonded_interactions/bmhtf-nacl.cpp

@@ -25,35 +25,26 @@
 #include "bmhtf-nacl.hpp"
 
 #ifdef BMHTF_NACL
-#include "interactions.hpp"
 #include "nonbonded_interactions/nonbonded_interaction_data.hpp"
 
-#include <utils/constants.hpp>
-
-int BMHTF_set_params(int part_type_a, int part_type_b, double A, double B,
-                     double C, double D, double sig, double cut) {
-  double shift, dist2, pw6;
-  IA_parameters *data = get_ia_param_safe(part_type_a, part_type_b);
-
-  if (!data)
-    return ES_ERROR;
-
-  dist2 = cut * cut;
-  pw6 = dist2 * dist2 * dist2;
-  shift = -(A * exp(B * (sig - cut)) - C / pw6 - D / pw6 / dist2);
-
-  data->bmhtf.A = A;
-  data->bmhtf.B = B;
-  data->bmhtf.C = C;
-  data->bmhtf.D = D;
-  data->bmhtf.sig = sig;
-  data->bmhtf.cut = cut;
-  data->bmhtf.computed_shift = shift;
-
-  /* broadcast interaction parameters */
-  mpi_bcast_ia_params(part_type_a, part_type_b);
-
-  return ES_OK;
+#include <utils/math/int_pow.hpp>
+
+#include <stdexcept>
+
+BMHTF_Parameters::BMHTF_Parameters(double a, double b, double c, double d,
+                                   double sig, double cutoff)
+    : A{a}, B{b}, C{c}, D{d}, sig{sig}, cut{cutoff} {
+  if (a < 0.) {
+    throw std::domain_error("BMHTF parameter 'a' has to be >= 0");
+  }
+  if (c < 0.) {
+    throw std::domain_error("BMHTF parameter 'c' has to be >= 0");
+  }
+  if (d < 0.) {
+    throw std::domain_error("BMHTF parameter 'd' has to be >= 0");
+  }
+  computed_shift = C / Utils::int_pow<6>(cut) + D / Utils::int_pow<8>(cut) -
+                   A * std::exp(B * (sig - cut));
 }
 
-#endif
+#endif // BMHTF_NACL

src/core/nonbonded_interactions/bmhtf-nacl.hpp

@@ -33,14 +33,10 @@
 
 #include "nonbonded_interaction_data.hpp"
 
-#include <utils/Vector.hpp>
 #include <utils/math/int_pow.hpp>
 
 #include <cmath>
 
-int BMHTF_set_params(int part_type_a, int part_type_b, double A, double B,
-                     double C, double D, double sig, double cut);
-
 /** Calculate BMHTF force factor */
 inline double BMHTF_pair_force_factor(IA_parameters const &ia_params,
                                       double dist) {
@@ -67,5 +63,5 @@ inline double BMHTF_pair_energy(IA_parameters const &ia_params, double dist) {
   return 0.0;
 }
 
-#endif
+#endif // BMHTF_NACL
 #endif

src/core/nonbonded_interactions/nonbonded_interaction_data.cpp

@@ -166,7 +166,7 @@ static double recalc_maximal_cutoff(const IA_parameters &data) {
 #endif
 
 #ifdef BMHTF_NACL
-  max_cut_current = std::max(max_cut_current, data.bmhtf.cut);
+  max_cut_current = std::max(max_cut_current, data.bmhtf.max_cutoff());
 #endif
 
 #ifdef MORSE

src/core/nonbonded_interactions/nonbonded_interaction_data.hpp

@@ -134,6 +134,10 @@ struct BMHTF_Parameters {
   double sig = 0.0;
   double cut = INACTIVE_CUTOFF;
   double computed_shift = 0.0;
+  BMHTF_Parameters() = default;
+  BMHTF_Parameters(double A, double B, double C, double D, double sig,
+                   double cut);
+  double max_cutoff() const { return cut; }
 };
 
 /** Morse potential */

src/python/espressomd/interactions.pxd

@@ -47,15 +47,6 @@ cdef extern from "nonbonded_interactions/nonbonded_interaction_data.hpp":
         int n
         double k0
 
-    cdef struct BMHTF_Parameters:
-        double A
-        double B
-        double C
-        double D
-        double sig
-        double cut
-        double computed_shift
-
     cdef struct Morse_Parameters:
         double eps
         double alpha
@@ -114,8 +105,6 @@ cdef extern from "nonbonded_interactions/nonbonded_interaction_data.hpp":
 
         SmoothStep_Parameters smooth_step
 
-        BMHTF_Parameters bmhtf
-
         Morse_Parameters morse
 
         Buckingham_Parameters buckingham
@@ -149,12 +138,6 @@ IF SMOOTH_STEP:
                                    double d, int n, double eps,
                                    double k0, double sig,
                                    double cut)
-IF BMHTF_NACL:
-    cdef extern from "nonbonded_interactions/bmhtf-nacl.hpp":
-        int BMHTF_set_params(int part_type_a, int part_type_b,
-                             double A, double B, double C,
-                             double D, double sig, double cut)
-
 IF MORSE:
     cdef extern from "nonbonded_interactions/morse.hpp":
         int morse_set_params(int part_type_a, int part_type_b,

src/python/espressomd/interactions.pyx

@@ -938,51 +938,41 @@ IF SMOOTH_STEP == 1:
 
 IF BMHTF_NACL == 1:
 
-    cdef class BMHTFInteraction(NonBondedInteraction):
+    @script_interface_register
+    class BMHTFInteraction(NewNonBondedInteraction):
+        """BMHTF interaction.
 
-        def validate_params(self):
-            """Check that parameters are valid.
+        Methods
+        -------
+        set_params()
+            Set or update parameters for the interaction.
+            Parameters marked as required become optional once the
+            interaction has been activated for the first time;
+            subsequent calls to this method update the existing values.
 
-            """
-            if self._params["a"] < 0:
-                raise ValueError("BMHTF a has to be >=0")
-            if self._params["c"] < 0:
-                raise ValueError("BMHTF c has to be >=0")
-            if self._params["d"] < 0:
-                raise ValueError("BMHTF d has to be >=0")
-            if self._params["cutoff"] < 0:
-                raise ValueError("BMHTF cutoff has to be >=0")
+            Parameters
+            ----------
+            a : :obj:`float`
+                Magnitude of exponential part of the interaction.
+            b : :obj:`float`
+                Exponential factor of the interaction.
+            c : :obj:`float`
+                Magnitude of the term decaying with the sixth power of r.
+            d : :obj:`float`
+                Magnitude of the term decaying with the eighth power of r.
+            sig : :obj:`float`
+                Shift in the exponent.
+            cutoff : :obj:`float`
+                Cutoff distance of the interaction.
+        """
 
-        def _get_params_from_es_core(self):
-            cdef IA_parameters * ia_params
-            ia_params = get_ia_param_safe(self._part_types[0],
-                                          self._part_types[1])
-            return {
-                "a": ia_params.bmhtf.A,
-                "b": ia_params.bmhtf.B,
-                "c": ia_params.bmhtf.C,
-                "d": ia_params.bmhtf.D,
-                "sig": ia_params.bmhtf.sig,
-                "cutoff": ia_params.bmhtf.cut,
-            }
+        _so_name = "Interactions::InteractionBMHTF"
 
         def is_active(self):
             """Check if interaction is active.
 
             """
-            return (self._params["a"] > 0) and (
-                self._params["c"] > 0) and (self._params["d"] > 0)
-
-        def _set_params_in_es_core(self):
-            if BMHTF_set_params(self._part_types[0],
-                                self._part_types[1],
-                                self._params["a"],
-                                self._params["b"],
-                                self._params["c"],
-                                self._params["d"],
-                                self._params["sig"],
-                                self._params["cutoff"]):
-                raise Exception("Could not set BMHTF parameters")
+            return self.a > 0. and self.c > 0. and self.d > 0.
 
         def default_params(self):
             """Python dictionary of default parameters.
@@ -996,28 +986,6 @@ IF BMHTF_NACL == 1:
             """
             return "BMHTF"
 
-        def set_params(self, **kwargs):
-            """
-            Set parameters for the BMHTF interaction.
-
-            Parameters
-            ----------
-            a : :obj:`float`
-                Magnitude of exponential part of the interaction.
-            b : :obj:`float`
-                Exponential factor of the interaction.
-            c : :obj:`float`
-                Magnitude of the term decaying with the sixth power of r.
-            d : :obj:`float`
-                Magnitude of the term decaying with the eighth power of r.
-            sig : :obj:`float`
-                Shift in the exponent.
-            cutoff : :obj:`float`
-                Cutoff distance of the interaction.
-
-            """
-            super().set_params(**kwargs)
-
         def valid_keys(self):
             """All parameters that can be set.
 
@@ -1438,8 +1406,6 @@ class NonBondedInteractionHandle(ScriptInterfaceHelper):
             self.soft_sphere = SoftSphereInteraction(_type1, _type2)
         IF SMOOTH_STEP:
             self.smooth_step = SmoothStepInteraction(_type1, _type2)
-        IF BMHTF_NACL:
-            self.bmhtf = BMHTFInteraction(_type1, _type2)
         IF MORSE:
             self.morse = MorseInteraction(_type1, _type2)
         IF BUCKINGHAM:

src/script_interface/interactions/NonBondedInteraction.hpp

@@ -357,6 +357,34 @@ class InteractionGaussian
 };
 #endif // GAUSSIAN
 
+#ifdef BMHTF_NACL
+class InteractionBMHTF
+    : public InteractionPotentialInterface<::BMHTF_Parameters> {
+protected:
+  CoreInteraction IA_parameters::*get_ptr_offset() const override {
+    return &::IA_parameters::bmhtf;
+  }
+
+public:
+  InteractionBMHTF() {
+    add_parameters({
+        make_autoparameter(&CoreInteraction::A, "a"),
+        make_autoparameter(&CoreInteraction::B, "b"),
+        make_autoparameter(&CoreInteraction::C, "c"),
+        make_autoparameter(&CoreInteraction::D, "d"),
+        make_autoparameter(&CoreInteraction::sig, "sig"),
+        make_autoparameter(&CoreInteraction::cut, "cutoff"),
+    });
+  }
+
+  void make_new_instance(VariantMap const &params) override {
+    m_ia_si = make_shared_from_args<CoreInteraction, double, double, double,
+                                    double, double, double>(
+        params, "a", "b", "c", "d", "sig", "cutoff");
+  }
+};
+#endif // BMHTF_NACL
+
 class NonBondedInteractionHandle
     : public AutoParameters<NonBondedInteractionHandle> {
   std::array<int, 2> m_types = {-1, -1};
@@ -382,6 +410,9 @@ class NonBondedInteractionHandle
 #ifdef GAUSSIAN
   std::shared_ptr<InteractionGaussian> m_gaussian;
 #endif
+#ifdef BMHTF_NACL
+  std::shared_ptr<InteractionBMHTF> m_bmhtf;
+#endif
 
   template <class T>
   auto make_autoparameter(std::shared_ptr<T> &member, const char *key) const {
@@ -420,6 +451,9 @@ class NonBondedInteractionHandle
 #endif
 #ifdef GAUSSIAN
         make_autoparameter(m_gaussian, "gaussian"),
+#endif
+#ifdef BMHTF_NACL
+        make_autoparameter(m_bmhtf, "bmhtf"),
 #endif
     });
   }
@@ -486,6 +520,10 @@ class NonBondedInteractionHandle
 #ifdef GAUSSIAN
     set_member<InteractionGaussian>(
         m_gaussian, "gaussian", "Interactions::InteractionGaussian", params);
+#endif
+#ifdef BMHTF_NACL
+    set_member<InteractionBMHTF>(m_bmhtf, "bmhtf",
+                                 "Interactions::InteractionBMHTF", params);
 #endif
   }
 

src/script_interface/interactions/initialize.cpp

@@ -77,6 +77,9 @@ void initialize(Utils::Factory<ObjectHandle> *om) {
 #ifdef GAUSSIAN
   om->register_new<InteractionGaussian>("Interactions::InteractionGaussian");
 #endif
+#ifdef BMHTF_NACL
+  om->register_new<InteractionBMHTF>("Interactions::InteractionBMHTF");
+#endif
 }
 } // namespace Interactions
 } // namespace ScriptInterface

testsuite/python/interactions_non-bonded_interface.py

@@ -289,6 +289,14 @@ def test_gaussian_exceptions(self):
             ("eps", "sig")
         )
 
+    @utx.skipIfMissingFeatures("BMHTF_NACL")
+    def test_bmhtf_exceptions(self):
+        self.check_potential_exceptions(
+            espressomd.interactions.BMHTFInteraction,
+            {"a": 3., "b": 2., "c": 1., "d": 4., "sig": 0.13, "cutoff": 1.2},
+            ("a", "c", "d")
+        )
+
 
 if __name__ == "__main__":
     ut.main()