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.xray;
39
40 import ffx.xray.RefinementMinimize.RefinementMode;
41
42 /**
43 * FormFactor interface.
44 *
45 * @author Timothy D. Fenn
46 * @since 1.0
47 */
48 public interface FormFactor {
49
50 /**
51 * Compute the real space density rho
52 *
53 * @param f the current density to modify
54 * @param lambda the state variable
55 * @param xyz the requested point for evaluating density
56 * @return the real space density value at xyz
57 */
58 double rho(double f, double lambda, double[] xyz);
59
60 /**
61 * Compute the real space gradient
62 *
63 * @param xyz the requested point for evaluating gradient
64 * @param dfc the multiplier to apply to the gradient
65 * @param refinementmode {@link ffx.xray.RefinementMinimize.RefinementMode} determines which
66 * gradients will be computed
67 */
68 void rhoGrad(double[] xyz, double dfc, RefinementMode refinementmode);
69
70 /**
71 * update the coordinates to the current position
72 *
73 * @param xyz an array of double.
74 */
75 void update(double[] xyz);
76
77 /**
78 * update the coordinates to the current position and Badd
79 *
80 * @param xyz an array of double.
81 * @param badd a double.
82 */
83 void update(double[] xyz, double badd);
84 }