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
32namespace WTF {
33class TextStream;
34}
35
36namespace WebCore {
37
38struct 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
65WEBCORE_EXPORT TextStream& operator<<(TextStream&, const VelocityData&);
66
67class HistoricalVelocityData {
68public:
69 HistoricalVelocityData() = default;
70
71 WEBCORE_EXPORT VelocityData velocityForNewData(FloatPoint newPosition, double scale, MonotonicTime);
72 void clear() { m_historySize = 0; }
73
74private:
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