15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright (c) 2012 The Chromium Authors. All rights reserved. 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// found in the LICENSE file. 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 568043e1e95eeb07d5cae7aca370b26518b0867d6Torne (Richard Coles)#ifndef UI_EVENTS_GESTURES_VELOCITY_CALCULATOR_H_ 668043e1e95eeb07d5cae7aca370b26518b0867d6Torne (Richard Coles)#define UI_EVENTS_GESTURES_VELOCITY_CALCULATOR_H_ 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <vector> 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/basictypes.h" 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/memory/scoped_ptr.h" 1268043e1e95eeb07d5cae7aca370b26518b0867d6Torne (Richard Coles)#include "ui/events/events_export.h" 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace ui { 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1668043e1e95eeb07d5cae7aca370b26518b0867d6Torne (Richard Coles)class EVENTS_EXPORT VelocityCalculator { 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) explicit VelocityCalculator(int bufferSize); 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ~VelocityCalculator(); 205d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) void PointSeen(float x, float y, int64 time); 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) float XVelocity(); 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) float YVelocity(); 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) float VelocitySquared(); 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void ClearHistory(); 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) private: 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) struct Point { 285d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) float x; 295d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) float y; 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int64 time; 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) }; 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void UpdateVelocity(); 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 352a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) typedef scoped_ptr<Point[]> HistoryBuffer; 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) HistoryBuffer buffer_; 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // index_ points directly after the last point added. 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int index_; 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) size_t num_valid_entries_; 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const size_t buffer_size_; 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) float x_velocity_; 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) float y_velocity_; 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool velocities_stale_; 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DISALLOW_COPY_AND_ASSIGN(VelocityCalculator); 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace ui 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 5068043e1e95eeb07d5cae7aca370b26518b0867d6Torne (Richard Coles)#endif // UI_EVENTS_GESTURES_VELOCITY_CALCULATOR_H_ 51