/src/ftk_interpolator_bounce.c

 1/*
 2 * File: ftk_interpolator_bounce.h    
 3 * Author:  Li XianJing <xianjimli@hotmail.com>
 4 * Brief:   bounce interpolator for animation.
 5 *
 6 * Copyright (c) 2009 - 2011  Li XianJing <xianjimli@hotmail.com>
 7 *
 8 * Licensed under the Academic Free License version 2.1
 9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
23 */
24
25/*
26 * History:
27 * ================================================================
28 * 2011-03-20 Li XianJing <xianjimli@hotmail.com> created
29 *
30 */
31
32#include "ftk_interpolator.h"
33
34static float ftk_interpolator_bounce_calc(float percent)
35{
36	return 8 * percent * percent;
37}
38
39static float ftk_interpolator_bounce_get(FtkInterpolator* thiz, float percent)
40{
41	percent *= 1.1226f;
42
43	if (percent < 0.3535f) 
44		return ftk_interpolator_bounce_calc(percent);
45	else if (percent < 0.7408f) 
46		return ftk_interpolator_bounce_calc(percent - 0.54719f) + 0.7f;
47	else if (percent < 0.9644f) 
48		return ftk_interpolator_bounce_calc(percent - 0.8526f) + 0.9f;
49	else 
50		return ftk_interpolator_bounce_calc(percent - 1.0435f) + 0.95f;
51}
52
53const static FtkInterpolator s_interpolator_bounce = 
54{
55	ftk_interpolator_bounce_get,
56	NULL
57};
58
59FtkInterpolator* ftk_interpolator_bounce_create(void)
60{
61	return (FtkInterpolator*)&s_interpolator_bounce;
62}
63