| Index: ui/events/gestures/velocity_calculator.cc
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| diff --git a/ui/events/gestures/velocity_calculator.cc b/ui/events/gestures/velocity_calculator.cc
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| deleted file mode 100644
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| index 37ec671b17f803819197f9f48ff670f2b1bc94b8..0000000000000000000000000000000000000000
|
| --- a/ui/events/gestures/velocity_calculator.cc
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| +++ /dev/null
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| @@ -1,114 +0,0 @@
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| -// Copyright (c) 2012 The Chromium Authors. All rights reserved.
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| -// Use of this source code is governed by a BSD-style license that can be
|
| -// found in the LICENSE file.
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| -
|
| -#include "ui/events/gestures/velocity_calculator.h"
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| -
|
| -namespace ui {
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| -
|
| -VelocityCalculator::VelocityCalculator(int buffer_size)
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| - : buffer_(new Point[buffer_size]) ,
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| - index_(0),
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| - num_valid_entries_(0),
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| - buffer_size_(buffer_size),
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| - x_velocity_(0),
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| - y_velocity_(0),
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| - velocities_stale_(false) {
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| -}
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| -
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| -VelocityCalculator::~VelocityCalculator() {}
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| -
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| -float VelocityCalculator::XVelocity() {
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| - if (velocities_stale_)
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| - UpdateVelocity();
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| - return x_velocity_;
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| -}
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| -
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| -float VelocityCalculator::YVelocity() {
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| - if (velocities_stale_)
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| - UpdateVelocity();
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| - return y_velocity_;
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| -}
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| -
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| -void VelocityCalculator::PointSeen(float x, float y, int64 time) {
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| - buffer_[index_].x = x;
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| - buffer_[index_].y = y;
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| - buffer_[index_].time = time;
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| -
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| - index_ = (index_ + 1) % buffer_size_;
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| - if (num_valid_entries_ < buffer_size_)
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| - ++num_valid_entries_;
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| -
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| - velocities_stale_ = true;
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| -}
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| -
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| -float VelocityCalculator::VelocitySquared() {
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| - if (velocities_stale_)
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| - UpdateVelocity();
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| - return x_velocity_ * x_velocity_ + y_velocity_ * y_velocity_;
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| -}
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| -
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| -void VelocityCalculator::UpdateVelocity() {
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| - // We don't have enough data to make a good estimate of the velocity.
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| - if (num_valid_entries_ < 2)
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| - return;
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| -
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| - // Where A_i = A[i] - mean(A)
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| - // x velocity = sum_i(x_i * t_i) / sum_i(t_i * t_i)
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| - // This is an Ordinary Least Squares Regression.
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| -
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| - float mean_x = 0;
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| - float mean_y = 0;
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| - int64 mean_time = 0;
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| -
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| - for (size_t i = 0; i < num_valid_entries_; ++i) {
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| - mean_x += buffer_[i].x;
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| - mean_y += buffer_[i].y;
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| - mean_time += buffer_[i].time;
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| - }
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| -
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| - // Minimize number of divides.
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| - const float num_valid_entries_i = 1.0f / num_valid_entries_;
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| -
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| - mean_x *= num_valid_entries_i;
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| - mean_y *= num_valid_entries_i;
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| -
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| - // The loss in accuracy due to rounding is insignificant compared to
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| - // the error due to the resolution of the timer.
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| - // Use integer division to avoid the cast to double, which would cause
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| - // VelocityCalculatorTest.IsAccurateWithLargeTimes to fail.
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| - mean_time /= num_valid_entries_;
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| -
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| - float xt = 0; // sum_i(x_i * t_i)
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| - float yt = 0; // sum_i(y_i * t_i)
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| - int64 tt = 0; // sum_i(t_i * t_i)
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| -
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| - int64 t_i;
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| -
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| - for (size_t i = 0; i < num_valid_entries_; ++i) {
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| - t_i = (buffer_[i].time - mean_time);
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| - xt += (buffer_[i].x - mean_x) * t_i;
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| - yt += (buffer_[i].y - mean_y) * t_i;
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| - tt += t_i * t_i;
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| - }
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| -
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| - if (tt > 0) {
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| - // Convert time from microseconds to seconds.
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| - x_velocity_ = xt / (tt / 1000000.0f);
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| - y_velocity_ = yt / (tt / 1000000.0f);
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| - } else {
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| - x_velocity_ = 0.0f;
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| - y_velocity_ = 0.0f;
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| - }
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| - velocities_stale_ = false;
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| -}
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| -
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| -void VelocityCalculator::ClearHistory() {
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| - index_ = 0;
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| - num_valid_entries_ = 0;
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| - x_velocity_ = 0;
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| - y_velocity_ = 0;
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| - velocities_stale_ = false;
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| -}
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| -
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| -} // namespace ui
|
|
|