OLD | NEW |
| 1 part of widgets; |
| 2 |
1 // Copyright 2015 The Chromium Authors. All rights reserved. | 3 // Copyright 2015 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 4 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 5 // found in the LICENSE file. |
4 | 6 |
5 import "dart:math" as math; | |
6 | |
7 const double _kDefaultAlpha = -5707.62; | 7 const double _kDefaultAlpha = -5707.62; |
8 const double _kDefaultBeta = 172.0; | 8 const double _kDefaultBeta = 172.0; |
9 const double _kDefaultGamma = 3.7; | 9 const double _kDefaultGamma = 3.7; |
10 | 10 |
11 double _positionAtTime(double t) { | 11 double _positionAtTime(double t) { |
12 return _kDefaultAlpha * math.exp(-_kDefaultGamma * t) | 12 return _kDefaultAlpha * math.exp(-_kDefaultGamma * t) |
13 - _kDefaultBeta * t | 13 - _kDefaultBeta * t |
14 - _kDefaultAlpha; | 14 - _kDefaultAlpha; |
15 } | 15 } |
16 | 16 |
(...skipping 29 matching lines...) Expand all Loading... |
46 double update(double timeStamp) { | 46 double update(double timeStamp) { |
47 double t = timeStamp / 1000.0 - _startTime + _timeOffset; | 47 double t = timeStamp / 1000.0 - _startTime + _timeOffset; |
48 if (t >= _kCurveDuration) | 48 if (t >= _kCurveDuration) |
49 return 0.0; | 49 return 0.0; |
50 double position = _positionAtTime(t) - _positionOffset; | 50 double position = _positionAtTime(t) - _positionOffset; |
51 double positionDelta = position - _previousPosition; | 51 double positionDelta = position - _previousPosition; |
52 _previousPosition = position; | 52 _previousPosition = position; |
53 return _direction * math.max(0.0, positionDelta); | 53 return _direction * math.max(0.0, positionDelta); |
54 } | 54 } |
55 } | 55 } |
OLD | NEW |