rebound-bind 5.0.0

Low-level Rust FFI bindings for the REBOUND N-body simulation C library.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102

/**
 * @file 	tree.h
 * @brief 	Tree header file. All the tree implementations needed by other routines.
 * @author 	Shangfei Liu <liushangfei@pku.edu.cn>, Hanno Rein <hanno@hanno-rein.de>
 *
 * @section 	LICENSE
 * Copyright (c) 2011 Hanno Rein, Shangfei Liu
 *
 * This file is part of rebound.
 *
 * rebound 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.
 *
 * rebound 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 rebound.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef _TREE_H
#define _TREE_H

struct reb_treecell; 

/**
 * @brief The data structure of one node of a tree 
 */
struct reb_treecell {
    double x; /**< The x position of the center of a cell */
    double y; /**< The y position of the center of a cell */
    double z; /**< The z position of the center of a cell */
    double w; /**< The width of a cell */
    double m; /**< The total mass of a cell */
    double mx; /**< The x position of the center of mass of a cell */
    double my; /**< The y position of the center of mass of a cell */
    double mz; /**< The z position of the center of mass of a cell */
#ifdef QUADRUPOLE
    double mxx; /**< The xx component of the quadrupole tensor of mass of a cell */
    double mxy; /**< The xy component of the quadrupole tensor of mass of a cell */
    double mxz; /**< The xz component of the quadrupole tensor of mass of a cell */
    double myy; /**< The yy component of the quadrupole tensor of mass of a cell */
    double myz; /**< The yz component of the quadrupole tensor of mass of a cell */
    double mzz; /**< The zz component of the quadrupole tensor of mass of a cell */
#endif // QUADRUPOLE
    struct reb_treecell *oct[8]; /**< The pointer array to the octants of a cell */
    int pt;		/**< It has double usages: in a leaf node, it stores the index 
                 * of a particle; in a non-leaf node, it equals to (-1)*Total 
                 * Number of particles within that cell. */ 
    int remote; /**< 0 by default. Set to 1 if this cell is part of an essential tree (MPI).*/ 
};

// The function loops over all trees to call calculate_forces_for_particle_from_cell() tree to calculate forces for each particle.
void reb_tree_calculate_acceleration_for_particle(const struct reb_simulation* const r, const int pt, const struct reb_vec6d gb);

/**
 * @brief construct tree by adding all particles currently in simulation.
 */
void reb_tree_construct(struct reb_simulation* const r);

/**
 * @brief The wrap function calls reb_tree_calculate_gravity_data_in_cell() for each tree.
 * @param r Rebound simulation to operate on
 */
void reb_tree_calculate_gravity_data(struct reb_simulation* const r);

/**
 * @brief The wrap function calls reb_tree_add_particle_to_cell() to add the particle into one of the trees. If the tree_root doesn't exist, then it initializes the tree. 
 * @param r Rebound simulation to operate on
 * @param pt Index of a particle.
 */
void reb_tree_add_particle_to_tree(struct reb_simulation* const r, int pt);

/**
 * @brief Free up all space occupied by the tree structure.
 * This will not modify particles.
 * @param r Rebound simulation to operate on
 */
void reb_tree_delete(struct reb_simulation* const r);

#ifdef MPI
/**
 * @brief MPI related function used to calculate gravity from nearby nodes
 * @param node is a pointer to a node cell.
 */
void reb_tree_add_essential_node(struct reb_simulation* const r, struct reb_treecell* node);
/**
 * @brief MPI related function used to calculate gravity from nearby nodes
 */
void reb_tree_prepare_essential_tree_for_gravity(struct reb_simulation* const r);
/**
 * @brief MPI related function used to calculate gravity from nearby nodes
 */
void reb_tree_prepare_essential_tree_for_collisions(struct reb_simulation* const r);
#endif // MPI

#endif // _TREE_H