1 /* 2 * Copyright (C) 2015 Nicolas Bonnefon and other contributors 3 * 4 * This file is part of glogg. 5 * 6 * glogg is free software: you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation, either version 3 of the License, or 9 * (at your option) any later version. 10 * 11 * glogg is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with glogg. If not, see <http://www.gnu.org/licenses/>. 18 */ 19 20 #include <chrono> 21 22 // This class is a counter that remembers the number of events occuring within one second 23 // it can be used for performance measurement (e.g. FPS) 24 25 class PerfCounter { 26 public: 27 PerfCounter() {} 28 29 // Count a new event, returns true if it has been counted. 30 // If the function returns false, it indicates the current second is elapsed 31 // and the user should read and reset the counter before re-adding the event. 32 bool addEvent() { 33 using namespace std::chrono; 34 if ( counter_ == 0 ) 35 first_event_date_ = steady_clock::now(); 36 37 if ( duration_cast<microseconds>( 38 steady_clock::now() - first_event_date_ ).count() < 1000000 ) { 39 ++counter_; 40 return true; 41 } 42 else { 43 return false; 44 } 45 } 46 47 // Read and reset the counter. Returns the number of events that occured in the 48 // previous second. 49 uint32_t readAndReset() { 50 uint32_t value = counter_; 51 counter_ = 0; 52 return value; 53 } 54 55 private: 56 uint32_t counter_ = 0; 57 std::chrono::steady_clock::time_point first_event_date_; 58 }; 59