1 /* 2 * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies) 3 * 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY 16 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR 19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 22 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 23 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include "fpstimer.h" 29 30 #include <QDateTime> 31 #include <QTimerEvent> 32 33 // We save a maximum of 10000 frames, and purge 2000 at a time 34 #define MAX_FRAMES_SAVED 10000 35 #define FRAMES_TO_PURGE_WHEN_FULL 2000 36 // 60 FPS 37 #define FPS_MEASURE_INTERVAL 1000 / 60 38 39 FpsTimer::FpsTimer(QObject* parent) 40 : QObject(parent) 41 , m_timer(0) 42 { 43 } 44 45 int FpsTimer::numFrames(int spanMillis) const 46 { 47 const QTime now = QTime::currentTime(); 48 49 int count = 0; 50 for (int i = m_frames.length() - 1; i >= 0; --i, ++count) { 51 int msecs = m_frames[i].msecsTo(now); 52 if (msecs < 0) 53 msecs += 24 * 60 * 60 * 1000; 54 if (msecs > spanMillis) 55 break; 56 } 57 return count; 58 } 59 60 void FpsTimer::start() 61 { 62 m_timer = startTimer(FPS_MEASURE_INTERVAL); 63 } 64 65 void FpsTimer::stop() 66 { 67 if (!m_timer) 68 return; 69 killTimer(m_timer); 70 m_frames.clear(); 71 } 72 73 void FpsTimer::timerEvent(QTimerEvent* event) 74 { 75 if (event->timerId() != m_timer) 76 return; 77 m_frames.append(QTime::currentTime()); 78 if (m_frames.length() > MAX_FRAMES_SAVED) 79 m_frames.erase(m_frames.begin(), m_frames.begin() + FRAMES_TO_PURGE_WHEN_FULL); 80 } 81
