VesinNeighbors.h

Go to the documentation of this file.

/*
** This file is part of eOn.
**
** SPDX-License-Identifier: BSD-3-Clause
**
** Shared neighbor lists via vesin (single NL backend for classical pots
** and Metatomic). Do not reimplement Verlet / link-cell / O(N^2) loops.
*/
#pragma once
 
#include <array>
#include <cstddef>
#include <cstdint>
#include <stdexcept>
#include <string>
 
// Vendored / system vesin C API
#include "vesin.h"
 
namespace eonc {

class VesinNeighbors {
public:
  struct Options {
    double cutoff{0.0};
    bool full{false}; 
    bool sorted{false};
    bool return_shifts{false};
    bool return_distances{true};
    bool return_vectors{true};
    std::array<bool, 3> periodic{{true, true, true}};
    double skin{0.0};
    int32_t n_threads{1};
    VesinAlgorithm algorithm{VesinAutoAlgorithm};
  };
 
  VesinNeighbors() = default;
  VesinNeighbors(const VesinNeighbors &) = delete;
  VesinNeighbors &operator=(const VesinNeighbors &) = delete;
  VesinNeighbors(VesinNeighbors &&other) noexcept;
  VesinNeighbors &operator=(VesinNeighbors &&other) noexcept;
  ~VesinNeighbors();

  void compute(const double *R, std::size_t n, const double *box,
               const Options &opt);
 
  [[nodiscard]] std::size_t size() const { return list_.length; }
 
  [[nodiscard]] std::size_t i(std::size_t p) const { return list_.pairs[p][0]; }
  [[nodiscard]] std::size_t j(std::size_t p) const { return list_.pairs[p][1]; }

  [[nodiscard]] double distance(std::size_t p) const {
    return list_.distances[p];
  }

  [[nodiscard]] const double *vector(std::size_t p) const {
    return list_.vectors[p];
  }
 
  [[nodiscard]] const int32_t *shift(std::size_t p) const {
    return list_.shifts[p];
  }

  [[nodiscard]] const VesinNeighborList &raw() const { return list_; }
  [[nodiscard]] VesinNeighborList &raw() { return list_; }

  VesinNeighborList *release();
 
private:
  VesinNeighborList list_{};
  bool owns_{false};
 
  void free_list();
};
 
} // namespace eonc