Source code: com/eireneh/bible/control/map/AntiGravityRule.java
1
2 package com.eireneh.bible.control.map;
3
4 import java.util.Vector;
5
6 import com.eireneh.bible.passage.*;
7 import com.eireneh.bible.book.*;
8 import com.eireneh.bible.control.search.*;
9
10 /**
11 * AntiGravityRule.
12 *
13 * <table border='1' cellPadding='3' cellSpacing='0' width="100%">
14 * <tr><td bgColor='white'class='TableRowColor'><font size='-7'>
15 * Distribution Licence:<br />
16 * Project B is free software; you can redistribute it
17 * and/or modify it under the terms of the GNU General Public License,
18 * version 2 as published by the Free Software Foundation.<br />
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 * General Public License for more details.<br />
23 * The License is available on the internet
24 * <a href='http://www.gnu.org/copyleft/gpl.html'>here</a>, by writing to
25 * <i>Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
26 * MA 02111-1307, USA</i>, Or locally at the Licence link below.<br />
27 * The copyright to this program is held by it's authors.
28 * </font></td></tr></table>
29 * @see <a href='http://www.eireneh.com/servlets/Web'>Project B Home</a>
30 * @see docs.Licence
31 * @author Joe Walker
32 * @version D0.I0.T0
33 */
34 public class AntiGravityRule extends AbstractRule
35 {
36 /**
37 * Specify where it would like a node to be positioned in space.
38 * @param map The Map to select a node from
39 * @param ord The ordinal number (1 - 31104) of the verse
40 * @return An array of desired positions.
41 */
42 public Position[] getDesiredPosition(Map map, int ord)
43 {
44 if (scale == 0)
45 return new Position[] { };
46
47 // The start point
48 float[] fpos = map.getPosition(ord);
49
50 // Where we move away from
51 float[] cog = map.getCenterOfGravity().getPosition();
52
53 // The desired position
54 float[] reply = new float[fpos.length];
55 for (int i=0; i<fpos.length; i++)
56 {
57 float distance = fpos[i] - cog[i];
58 reply[i] = (0.3F * (float) Math.atan(distance*GRADIENT)) + 0.5F;
59 }
60
61 return scale(new Position(reply));
62 }
63
64 /** How sharply do we fall away with the result curve */
65 private static final float GRADIENT = 10F;
66 }