core: Move Particle declaration to separate file

src/core/Particle.hpp

@@ -0,0 +1,338 @@
+/*
+ * Copyright (C) 2010-2019 The ESPResSo project
+ *
+ * This file is part of ESPResSo.
+ *
+ * ESPResSo is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * ESPResSo is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef ESPRESSO_CORE_PARTICLE_HPP
+#define ESPRESSO_CORE_PARTICLE_HPP
+
+#include "config.hpp"
+
+#include <utils/List.hpp>
+#include <utils/Vector.hpp>
+#include <utils/math/quaternion.hpp>
+
+/** Properties of a particle which are not supposed to
+ *  change during the integration, but have to be known
+ *  for all ghosts. Ghosts are particles which are
+ *  needed in the interaction calculation, but are just copies of
+ *  particles stored on different nodes.
+ */
+struct ParticleProperties {
+  /** unique identifier for the particle. */
+  int identity = -1;
+  /** Molecule identifier. */
+  int mol_id = 0;
+  /** particle type, used for non bonded interactions. */
+  int type = 0;
+
+  /** particle mass */
+#ifdef MASS
+  double mass = 1.0;
+#else
+  constexpr static double mass{1.0};
+#endif /* MASS */
+
+#ifdef ROTATIONAL_INERTIA
+  /** rotational inertia */
+  Utils::Vector3d rinertia = {1., 1., 1.};
+#else
+  static constexpr Utils::Vector3d rinertia = {1., 1., 1.};
+#endif
+
+#ifdef MEMBRANE_COLLISION
+  /** parameters for membrane collision mechanisms */
+  Utils::Vector3d out_direction = {0., 0., 0.};
+#endif
+
+  /** bitfield for the particle axes of rotation */
+  int rotation = 0;
+
+  /** charge. */
+#ifdef ELECTROSTATICS
+  double q = 0.0;
+#else
+  constexpr static double q{0.0};
+#endif
+
+#ifdef LB_ELECTROHYDRODYNAMICS
+  /** electrophoretic mobility times E-field: mu_0 * E */
+  Utils::Vector3d mu_E = {0., 0., 0.};
+#endif
+
+#ifdef DIPOLES
+  /** dipole moment (absolute value) */
+  double dipm = 0.;
+#endif
+
+#ifdef VIRTUAL_SITES
+  /** is particle virtual */
+  bool is_virtual = false;
+#ifdef VIRTUAL_SITES_RELATIVE
+  /** The following properties define, with respect to which real particle a
+   *  virtual site is placed and at what distance. The relative orientation of
+   *  the vector pointing from real particle to virtual site with respect to the
+   *  orientation of the real particle is stored in the virtual site's
+   *  quaternion attribute.
+   */
+  struct VirtualSitesRelativeParameters {
+    int to_particle_id = 0;
+    double distance = 0;
+    /** Relative position of the virtual site. */
+    Utils::Vector4d rel_orientation = {0., 0., 0., 0.};
+    /** Orientation of the virtual particle in the body fixed frame. */
+    Utils::Vector4d quat = {0., 0., 0., 0.};
+
+    template <class Archive> void serialize(Archive &ar, long int) {
+      ar &to_particle_id;
+      ar &distance;
+      ar &rel_orientation;
+      ar &quat;
+    }
+  } vs_relative;
+#endif
+#else  /* VIRTUAL_SITES */
+  static constexpr const bool is_virtual = false;
+#endif /* VIRTUAL_SITES */
+
+#ifdef LANGEVIN_PER_PARTICLE
+  double T = -1.;
+#ifndef PARTICLE_ANISOTROPY
+  double gamma = -1.;
+#else
+  Utils::Vector3d gamma = {-1., -1., -1.};
+#endif // PARTICLE_ANISOTROPY
+/** Friction coefficient gamma for rotation */
+#ifdef ROTATION
+#ifndef PARTICLE_ANISOTROPY
+  double gamma_rot = -1.;
+#else
+  Utils::Vector3d gamma_rot = {-1., -1., -1.};
+#endif // ROTATIONAL_INERTIA
+#endif // ROTATION
+#endif // LANGEVIN_PER_PARTICLE
+
+#ifdef EXTERNAL_FORCES
+  /** flag whether to fix a particle in space.
+      Values:
+      <ul> <li> 0 no external influence
+           <li> 1 apply external force \ref ParticleProperties::ext_force
+           <li> 2,3,4 fix particle coordinate 0,1,2
+           <li> 5 apply external torque \ref ParticleProperties::ext_torque
+      </ul>
+  */
+  int ext_flag = 0;
+  /** External force, apply if \ref ParticleProperties::ext_flag == 1. */
+  Utils::Vector3d ext_force = {0, 0, 0};
+
+#ifdef ROTATION
+  /** External torque, apply if \ref ParticleProperties::ext_flag == 16. */
+  Utils::Vector3d ext_torque = {0, 0, 0};
+#endif
+#endif
+};
+
+/** Positional information on a particle. Information that is
+ *  communicated to calculate interactions with ghost particles.
+ */
+struct ParticlePosition {
+  /** periodically folded position. */
+  Utils::Vector3d p = {0, 0, 0};
+
+#ifdef ROTATION
+  /** quaternion to define particle orientation */
+  Utils::Vector4d quat = {1., 0., 0., 0.};
+  /** unit director calculated from the quaternion */
+  Utils::Vector3d calc_director() const {
+    return Utils::convert_quaternion_to_director(quat);
+  };
+#endif
+
+#ifdef BOND_CONSTRAINT
+  /** particle position at the previous time step */
+  Utils::Vector3d p_old = {0., 0., 0.};
+#endif
+};
+
+/** Force information on a particle. Forces of ghost particles are
+ *  collected and added up to the force of the original particle.
+ */
+struct ParticleForce {
+  ParticleForce() = default;
+  ParticleForce(ParticleForce const &) = default;
+  ParticleForce(const Utils::Vector3d &f) : f(f) {}
+#ifdef ROTATION
+  ParticleForce(const Utils::Vector3d &f, const Utils::Vector3d &torque)
+      : f(f), torque(torque) {}
+#endif
+
+  ParticleForce &operator+=(ParticleForce const &rhs) {
+    f += rhs.f;
+#ifdef ROTATION
+    torque += rhs.torque;
+#endif
+
+    return *this;
+  }
+
+  /** force. */
+  Utils::Vector3d f = {0., 0., 0.};
+
+#ifdef ROTATION
+  /** torque */
+  Utils::Vector3d torque = {0., 0., 0.};
+#endif
+};
+
+/** Momentum information on a particle. Information not contained in
+    communication of ghost particles so far, but a communication would
+    be necessary for velocity dependent potentials. */
+struct ParticleMomentum {
+  /** velocity. */
+  Utils::Vector3d v = {0., 0., 0.};
+
+#ifdef ROTATION
+  /** angular velocity
+      ALWAYS IN PARTICLE FIXED, I.E., CO-ROTATING COORDINATE SYSTEM */
+  Utils::Vector3d omega = {0., 0., 0.};
+#endif
+};
+
+/** Information on a particle that is needed only on the
+ *  node the particle belongs to
+ */
+struct ParticleLocal {
+  /** check whether a particle is a ghost or not */
+  bool ghost = false;
+  /** position in the last time step before last Verlet list update. */
+  Utils::Vector3d p_old = {0, 0, 0};
+  /** index of the simulation box image where the particle really sits. */
+  Utils::Vector3i i = {0, 0, 0};
+};
+
+struct ParticleParametersSwimming {
+// ifdef inside because we need this type for some MPI prototypes
+#ifdef ENGINE
+  bool swimming = false;
+  double f_swim = 0.;
+  double v_swim = 0.;
+  int push_pull = 0;
+  double dipole_length = 0.;
+  Utils::Vector3d v_center;
+  Utils::Vector3d v_source;
+  double rotational_friction = 0.;
+#endif
+
+  template <typename Archive> void serialize(Archive &ar, long int) {
+#ifdef ENGINE
+    ar &swimming &f_swim &v_swim &push_pull &dipole_length &v_center &v_source
+        &rotational_friction;
+#endif
+  }
+};
+
+/** Struct holding all information for one particle. */
+struct Particle {
+  int &identity() { return p.identity; }
+  int const &identity() const { return p.identity; }
+
+  bool operator==(Particle const &rhs) const {
+    return identity() == rhs.identity();
+  }
+
+  bool operator!=(Particle const &rhs) const {
+    return identity() != rhs.identity();
+  }
+
+  /**
+   * @brief Return a copy of the particle with
+   *        only the fixed size parts.
+   *
+   * This creates a copy of the particle with
+   * only the parts than can be copied w/o heap
+   * allocation, e.g. w/o bonds and exclusions.
+   * This is more efficient if these parts are
+   * not actually needed.
+   */
+  Particle flat_copy() const {
+    Particle ret;
+
+    ret.p = p;
+    ret.r = r;
+    ret.m = m;
+    ret.f = f;
+    ret.l = l;
+#ifdef ENGINE
+    ret.swim = swim;
+#endif
+
+    return ret;
+  }
+
+  ///
+  ParticleProperties p;
+  ///
+  ParticlePosition r;
+#ifdef DIPOLES
+  Utils::Vector3d calc_dip() const { return r.calc_director() * p.dipm; }
+#endif
+  ///
+  ParticleMomentum m;
+  ///
+  ParticleForce f;
+  ///
+  ParticleLocal l;
+
+  /** Bonded interactions list
+   *
+   *  The format is pretty simple: just the bond type, and then the particle
+   *  ids. The number of particle ids can be determined easily from the
+   *  bonded_ia_params entry for the type.
+   */
+  IntList bl;
+
+  IntList &bonds() { return bl; }
+  IntList const &bonds() const { return bl; }
+
+  IntList &exclusions() {
+#ifdef EXCLUSIONS
+    return el;
+#else
+    throw std::runtime_error{"Exclusions not enabled."};
+#endif
+  }
+
+  IntList const &exclusions() const {
+#ifdef EXCLUSIONS
+    return el;
+#else
+    throw std::runtime_error{"Exclusions not enabled."};
+#endif
+  }
+
+#ifdef EXCLUSIONS
+  /** list of particles, with which this particle has no nonbonded
+   *  interactions
+   */
+  IntList el;
+#endif
+
+#ifdef ENGINE
+  ParticleParametersSwimming swim;
+#endif
+};
+
+#endif