1/* 2 * Copyright (c) 2014, Google 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 are 6 * met: 7 * 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above 11 * copyright notice, this list of conditions and the following disclaimer 12 * in the documentation and/or other materials provided with the 13 * distribution. 14 * * Neither the name of Google Inc. nor the names of its 15 * contributors may be used to endorse or promote products derived from 16 * this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31#include "config.h" 32#include "core/animation/AnimationClock.h" 33 34#include "wtf/CurrentTime.h" 35#include <math.h> 36 37namespace { 38 39// FIXME: This is an approximation of time between frames, used when 40// ticking the animation clock outside of animation frame callbacks. 41// Ideally this would be generated by the compositor. 42const double approximateFrameTime = 1 / 60.0; 43 44} 45 46namespace blink { 47 48unsigned AnimationClock::s_currentTask = 0; 49 50void AnimationClock::updateTime(double time) 51{ 52 if (time > m_time) 53 m_time = time; 54 m_currentTask = s_currentTask; 55} 56 57double AnimationClock::currentTime() 58{ 59 if (m_currentTask != s_currentTask) { 60 const double currentTime = m_monotonicallyIncreasingTime(); 61 if (m_time < currentTime) { 62 // Advance to the first estimated frame after the current time. 63 const double frameShift = fmod(currentTime - m_time, approximateFrameTime); 64 const double newTime = currentTime + (approximateFrameTime - frameShift); 65 ASSERT(newTime >= currentTime); 66 ASSERT(newTime <= currentTime + approximateFrameTime); 67 updateTime(newTime); 68 } else { 69 m_currentTask = s_currentTask; 70 } 71 } 72 return m_time; 73} 74 75void AnimationClock::resetTimeForTesting(double time) 76{ 77 m_time = time; 78 m_currentTask = 0; 79 s_currentTask = 0; 80} 81 82} 83