1 | /* |
2 | * Copyright (C) 2012-2019 Apple Inc. All rights reserved. |
3 | * |
4 | * Redistribution and use in source and binary forms, with or without |
5 | * modification, are permitted provided that the following conditions |
6 | * are met: |
7 | * 1. Redistributions of source code must retain the above copyright |
8 | * notice, this list of conditions and the following disclaimer. |
9 | * 2. Redistributions in binary form must reproduce the above copyright |
10 | * notice, this list of conditions and the following disclaimer in the |
11 | * documentation and/or other materials provided with the distribution. |
12 | * |
13 | * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' |
14 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
15 | * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
16 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS |
17 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
18 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
19 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
20 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
21 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
22 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF |
23 | * THE POSSIBILITY OF SUCH DAMAGE. |
24 | */ |
25 | |
26 | #pragma once |
27 | |
28 | #include "FloatPoint.h" |
29 | #include <wtf/MonotonicTime.h> |
30 | #include <wtf/Optional.h> |
31 | |
32 | namespace WTF { |
33 | class TextStream; |
34 | } |
35 | |
36 | namespace WebCore { |
37 | |
38 | struct VelocityData { |
39 | float horizontalVelocity { 0 }; |
40 | float verticalVelocity { 0 }; |
41 | float scaleChangeRate { 0 }; |
42 | MonotonicTime lastUpdateTime; |
43 | |
44 | VelocityData(float horizontal = 0, float vertical = 0, float scaleChange = 0, MonotonicTime updateTime = MonotonicTime()) |
45 | : horizontalVelocity(horizontal) |
46 | , verticalVelocity(vertical) |
47 | , scaleChangeRate(scaleChange) |
48 | , lastUpdateTime(updateTime) |
49 | { |
50 | } |
51 | |
52 | bool velocityOrScaleIsChanging() const |
53 | { |
54 | return horizontalVelocity || verticalVelocity || scaleChangeRate; |
55 | } |
56 | |
57 | bool equalIgnoringTimestamp(const VelocityData& other) const |
58 | { |
59 | return horizontalVelocity == other.horizontalVelocity |
60 | && verticalVelocity == other.verticalVelocity |
61 | && scaleChangeRate == other.scaleChangeRate; |
62 | } |
63 | }; |
64 | |
65 | WEBCORE_EXPORT TextStream& operator<<(TextStream&, const VelocityData&); |
66 | |
67 | class HistoricalVelocityData { |
68 | public: |
69 | HistoricalVelocityData() = default; |
70 | |
71 | WEBCORE_EXPORT VelocityData velocityForNewData(FloatPoint newPosition, double scale, MonotonicTime); |
72 | void clear() { m_historySize = 0; } |
73 | |
74 | private: |
75 | static constexpr unsigned maxHistoryDepth = 3; |
76 | |
77 | unsigned m_historySize { 0 }; |
78 | unsigned m_latestDataIndex { 0 }; |
79 | MonotonicTime m_lastAppendTimestamp; |
80 | |
81 | struct Data { |
82 | MonotonicTime timestamp; |
83 | FloatPoint position; |
84 | double scale; |
85 | } m_positionHistory[maxHistoryDepth]; |
86 | }; |
87 | |
88 | } // namespace WebCore |
89 | |