1 // ******************************************************************************
2 //
3 // Title: Force Field X.
4 // Description: Force Field X - Software for Molecular Biophysics.
5 // Copyright: Copyright (c) Michael J. Schnieders 2001-2025.
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.openmm;
39
40 import static edu.uiowa.jopenmm.OpenMMLibrary.OpenMM_PeriodicTorsionForce_addTorsion;
41 import static edu.uiowa.jopenmm.OpenMMLibrary.OpenMM_PeriodicTorsionForce_create;
42 import static edu.uiowa.jopenmm.OpenMMLibrary.OpenMM_PeriodicTorsionForce_destroy;
43 import static edu.uiowa.jopenmm.OpenMMLibrary.OpenMM_PeriodicTorsionForce_setTorsionParameters;
44 import static edu.uiowa.jopenmm.OpenMMLibrary.OpenMM_PeriodicTorsionForce_updateParametersInContext;
45
46 /**
47 * Periodic Torsion Force.
48 */
49 public class PeriodicTorsionForce extends Force {
50
51 public PeriodicTorsionForce() {
52 pointer = OpenMM_PeriodicTorsionForce_create();
53 }
54
55 /**
56 * Add a torsion to the PeriodicTorsionForce.
57 *
58 * @param particle1 Index of the first atom.
59 * @param particle2 Index of the second atom.
60 * @param particle3 Index of the third atom.
61 * @param particle4 Index of the fourth atom.
62 * @param periodicity The periodicity of the torsion.
63 * @param phase The phase of the torsion.
64 * @param k The force constant for the torsion.
65 */
66 public void addTorsion(int particle1, int particle2, int particle3, int particle4, int periodicity, double phase, double k) {
67 OpenMM_PeriodicTorsionForce_addTorsion(pointer, particle1, particle2, particle3, particle4, periodicity, phase, k);
68 }
69
70 /**
71 * Set the parameters for a torsion.
72 *
73 * @param index The index of the torsion for which to set parameters.
74 * @param particle1 The index of the first atom in the torsion.
75 * @param particle2 The index of the second atom in the torsion.
76 * @param particle3 The index of the third atom in the torsion.
77 * @param particle4 The index of the fourth atom in the torsion.
78 * @param periodicity The periodicity of the torsion.
79 * @param phase The phase of the torsion.
80 * @param k The force constant for the torsion.
81 */
82 public void setTorsionParameters(int index, int particle1, int particle2, int particle3, int particle4, int periodicity, double phase, double k) {
83 OpenMM_PeriodicTorsionForce_setTorsionParameters(pointer, index, particle1, particle2, particle3, particle4, periodicity, phase, k);
84 }
85
86 /**
87 * Update the parameters for a torsion in the OpenMM Context.
88 *
89 * @param context The OpenMM Context.
90 */
91 public void updateParametersInContext(Context context) {
92 if (context.hasContextPointer()) {
93 OpenMM_PeriodicTorsionForce_updateParametersInContext(pointer, context.getPointer());
94 }
95 }
96
97 public void destroy() {
98 if (pointer != null) {
99 OpenMM_PeriodicTorsionForce_destroy(pointer);
100 pointer = null;
101 }
102 }
103
104 }