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1   // ******************************************************************************
2   //
3   // Title:       Force Field X.
4   // Description: Force Field X - Software for Molecular Biophysics.
5   // Copyright:   Copyright (c) Michael J. Schnieders 2001-2024.
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 }