1 // ******************************************************************************
2 //
3 // Title: Force Field X.
4 // Description: Force Field X - Software for Molecular Biophysics.
5 // Copyright: Copyright (c) Michael J. Schnieders 2001-2023.
6 //
7 // This file is part of Force Field X.
8 //
9 // Force Field X is free software; you can redistribute it and/or modify it
10 // under the terms of the GNU General Public License version 3 as published by
11 // the Free Software Foundation.
12 //
13 // Force Field X is distributed in the hope that it will be useful, but WITHOUT
14 // ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
15 // FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
16 // details.
17 //
18 // You should have received a copy of the GNU General Public License along with
19 // Force Field X; if not, write to the Free Software Foundation, Inc., 59 Temple
20 // Place, Suite 330, Boston, MA 02111-1307 USA
21 //
22 // Linking this library statically or dynamically with other modules is making a
23 // combined work based on this library. Thus, the terms and conditions of the
24 // GNU General Public License cover the whole combination.
25 //
26 // As a special exception, the copyright holders of this library give you
27 // permission to link this library with independent modules to produce an
28 // executable, regardless of the license terms of these independent modules, and
29 // to copy and distribute the resulting executable under terms of your choice,
30 // provided that you also meet, for each linked independent module, the terms
31 // and conditions of the license of that module. An independent module is a
32 // module which is not derived from or based on this library. If you modify this
33 // library, you may extend this exception to your version of the library, but
34 // you are not obligated to do so. If you do not wish to do so, delete this
35 // exception statement from your version.
36 //
37 // ******************************************************************************
38 package ffx.potential.openmm;
39
40 import com.sun.jna.Pointer;
41 import com.sun.jna.ptr.PointerByReference;
42
43 import static edu.uiowa.jopenmm.OpenMMLibrary.OpenMM_Boolean.OpenMM_True;
44 import static edu.uiowa.jopenmm.OpenMMLibrary.OpenMM_Force_getForceGroup;
45 import static edu.uiowa.jopenmm.OpenMMLibrary.OpenMM_Force_getName;
46 import static edu.uiowa.jopenmm.OpenMMLibrary.OpenMM_Force_setForceGroup;
47 import static edu.uiowa.jopenmm.OpenMMLibrary.OpenMM_Force_setName;
48 import static edu.uiowa.jopenmm.OpenMMLibrary.OpenMM_Force_usesPeriodicBoundaryConditions;
49
50 /**
51 * OpenMM Force.
52 */
53 public abstract class OpenMMForce {
54
55 /**
56 * The forcePointer is allocated and deallocated by classes that extend OpenMMForce.
57 */
58 protected PointerByReference forcePointer = null;
59
60 /**
61 * The forceIndex is returned by OpenMMSystem.addForce and is used to remove the force.
62 */
63 private int forceIndex = -1;
64
65 /**
66 * Get the pointer to the OpenMM Force.
67 *
68 * @return The pointer to the OpenMM Force.
69 */
70 public PointerByReference getPointer() {
71 return forcePointer;
72 }
73
74 /**
75 * Construct an OpenMM Force from an OpenMMEnergy.
76 *
77 * @param openMMEnergy The OpenMMEnergy.
78 * @return An OpenMM Force.
79 */
80 public static OpenMMForce constructForce(OpenMMEnergy openMMEnergy) {
81 return null;
82 }
83
84 /**
85 * Set the force group.
86 *
87 * @param forceGroup The force group.
88 */
89 public void setForceGroup(int forceGroup) {
90 OpenMM_Force_setForceGroup(forcePointer, forceGroup);
91 }
92
93 /**
94 * Get the force group.
95 *
96 * @return The force group.
97 */
98 public int getForceGroup() {
99 return OpenMM_Force_getForceGroup(forcePointer);
100 }
101
102 /**
103 * Set the name of the force.
104 *
105 * @param name The name of the force.
106 */
107 public void setName(String name) {
108 OpenMM_Force_setName(forcePointer, name);
109 }
110
111 /**
112 * Get the name of the force.
113 *
114 * @return The name of the force.
115 */
116 public String getName() {
117 Pointer pointer = OpenMM_Force_getName(forcePointer);
118 if (pointer == null) {
119 return null;
120 }
121 return pointer.getString(0);
122 }
123
124 /**
125 * Set the force index.
126 *
127 * @param forceIndex The force index.
128 */
129 public void setForceIndex(int forceIndex) {
130 this.forceIndex = forceIndex;
131 }
132
133 /**
134 * Get the force index.
135 *
136 * @return The force index.
137 */
138 public int getForceIndex() {
139 return forceIndex;
140 }
141
142 /**
143 * Check if the force use periodic boundary conditions. This is a virtual method
144 * that must be implemented by classes that extend OpenMMForce.
145 *
146 * @return True if the force uses periodic boundary conditions.
147 */
148 public boolean usesPeriodicBoundaryConditions() {
149 int pbc = OpenMM_Force_usesPeriodicBoundaryConditions(forcePointer);
150 return pbc == OpenMM_True;
151 }
152
153 }