blob: 4e44d44d352e2d40533f0bec3b353bb2ec62cf53 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
|
// Copyright 2019 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef UI_BASE_PREDICTION_LINEAR_RESAMPLING_H_
#define UI_BASE_PREDICTION_LINEAR_RESAMPLING_H_
#include <deque>
#include "base/component_export.h"
#include "ui/base/prediction/input_predictor.h"
namespace ui {
// This class use linear extrapolates / interpolates to resample events to
// frame_time - kResampleLatency. This resampling logic is to match the
// resampling behavior on Android. It's not designed for pointerevent's
// PredictedEvent and should not be used for that purpose.
// Resampling on Android see:
// https://android.googlesource.com/platform/frameworks/native/+/master/libs/input/InputTransport.cpp
class COMPONENT_EXPORT(UI_BASE_PREDICTION) LinearResampling
: public InputPredictor {
public:
explicit LinearResampling();
~LinearResampling() override;
const char* GetName() const override;
// Reset the predictor to initial state.
void Reset() override;
// Store current input in queue.
void Update(const InputData& new_input) override;
// Return if there is enough data in the queue to generate prediction.
bool HasPrediction() const override;
// Generate the prediction based on stored points and given frame_time.
// Return false if no prediction available.
std::unique_ptr<InputData> GeneratePrediction(
base::TimeTicks frame_time) const override;
// Return the average time delta in the event queue.
base::TimeDelta TimeInterval() const override;
private:
static constexpr size_t kNumEventsForResampling = 2;
// Store the last events received
std::deque<InputData> events_queue_;
// Store the current delta time between the last 2 events
base::TimeDelta events_dt_;
DISALLOW_COPY_AND_ASSIGN(LinearResampling);
};
} // namespace ui
#endif // UI_BASE_PREDICTION_LINEAR_RESAMPLING_H_
|
