1/*
2 * Copyright (C) 2001 Robert Penner. All rights reserved.
3 * Copyright (C) 2013 Samsung Electronics. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the author nor the names of contributors may be
14 *    used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS"AS IS"
18 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
21 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27 * POSSIBILITY OF SUCH DAMAGE.
28 */
29
30/*
31 * Robert Penner's easing equations. http://www.robertpenner.com/easing/
32 * static function easeInOutQuad (t:Number, b:Number, c:Number, d:Number):Number {
33 *     if ((t/=d/2) < 1) return c/2*t*t + b;
34 *     return -c/2 * ((--t)*(t-2) - 1) + b;
35 * }
36 */
37namespace WebKit {
38
39float easeInOutQuad(float time, const float base, const float constant, const unsigned duration)
40{
41    if (time > duration || time < 0)
42        return 0;
43
44    if ((time /= (duration / 2)) < 1)
45        return (constant / 2) * time * time + base;
46
47    time -= 1;
48    return -1 * (constant / 2) * (time * (time - 2) - 1) + base;
49}
50
51} // namespace WebKit
52