1 /*
2
3 dsh-interpolate Interpolation and easing functions.
4 Copyright (c) 2009-2013 held jointly by the individual authors.
5
6 This library is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as published
8 by the Free Software Foundation; either version 3 of the License, or (at
9 your option) any later version.
10
11 This library is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; with out even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
14 License for more details.
15
16 You should have received a copy of the GNU Lesser General Public License
17 along with this library; if not, write to the Free Software Foundation,
18 Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
19
20 > http://www.fsf.org/licensing/licenses/lgpl.html
21 > http://www.opensource.org/licenses/lgpl-license.php
22
23 */
24 package org.dishevelled.interpolate;
25
26 /**
27 * Abstract bounce easing interpolation function.
28 *
29 * @author Michael Heuer
30 * @version $Revision$ $Date$
31 */
32 abstract class AbstractBounceEasingFunction
33 implements EasingFunction
34 {
35
36 /**
37 * Return the interpolated ease in value.
38 *
39 * @param value value to interpolate
40 * @return the interpolated ease in value
41 */
42 protected final Double easeIn(final Double value)
43 {
44 return 1.0d - easeOut(1.0d - value);
45 }
46
47 /**
48 * Return the interpolated ease out value.
49 *
50 * @param value value to interpolate
51 * @return the interpolated ease out value
52 */
53 protected final Double easeOut(final Double value)
54 {
55 if (value < (1.0d / 2.75d))
56 {
57 return value * value * 7.5625d;
58 }
59 else if (value < (2.0d / 2.75d))
60 {
61 double v = value - (1.5d / 2.75d);
62 return v * v * 7.5625d + 0.75d;
63 }
64 else if (value < (2.5d / 2.75d))
65 {
66 double v = value - (2.25d / 2.75d);
67 return v * v * 7.5625d + 0.9375d;
68 }
69 double v = value - (2.625d / 2.75d);
70 return v * v * 7.5625d + 0.984375d;
71 }
72 }