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_CustomExternalForce_addParticle;
41 import static edu.uiowa.jopenmm.OpenMMLibrary.OpenMM_CustomExternalForce_addPerParticleParameter;
42 import static edu.uiowa.jopenmm.OpenMMLibrary.OpenMM_CustomExternalForce_create;
43 import static edu.uiowa.jopenmm.OpenMMLibrary.OpenMM_CustomExternalForce_destroy;
44
45 /**
46 * Custom External Force.
47 */
48 public class CustomExternalForce extends Force {
49
50 /**
51 * OpenMM CustomExternalForce constructor.
52 *
53 * @param energy The energy expression.
54 */
55 public CustomExternalForce(String energy) {
56 pointer = OpenMM_CustomExternalForce_create(energy);
57 }
58
59 /**
60 * Add per particle parameter.
61 *
62 * @param parameterName The parameter name.
63 */
64 public void addPerParticleParameter(String parameterName) {
65 OpenMM_CustomExternalForce_addPerParticleParameter(pointer, parameterName);
66 }
67
68 /**
69 * Add a particle to the force.
70 *
71 * @param index The particle index.
72 * @param particleParameters The particle parameters.
73 */
74 public void addParticle(int index, DoubleArray particleParameters) {
75 OpenMM_CustomExternalForce_addParticle(pointer, index, particleParameters.getPointer());
76 }
77
78 /**
79 * Destroy the force.
80 */
81 public void destroy() {
82 if (pointer != null) {
83 OpenMM_CustomExternalForce_destroy(pointer);
84 pointer = null;
85 }
86 }
87
88 }