1 // Copyright 2013 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include <time.h> 6 #include <limits> 7 8 #include "nacl_app/flock.h" 9 10 void FrameCounter::BeginFrame() { 11 struct timeval start_time; 12 gettimeofday(&start_time, NULL); 13 frame_start_ = start_time.tv_sec * kMicroSecondsPerSecond + 14 start_time.tv_usec; 15 } 16 17 void FrameCounter::EndFrame() { 18 struct timeval end_time; 19 gettimeofday(&end_time, NULL); 20 double frame_end = end_time.tv_sec * kMicroSecondsPerSecond + 21 end_time.tv_usec; 22 double dt = frame_end - frame_start_; 23 if (dt < 0) 24 return; 25 frame_duration_accumulator_ += dt; 26 frame_count_++; 27 if (frame_count_ > kFrameRateRefreshCount || 28 frame_duration_accumulator_ >= kMicroSecondsPerSecond) { 29 double elapsed_time = frame_duration_accumulator_ / 30 kMicroSecondsPerSecond; 31 if (fabs(elapsed_time) > std::numeric_limits<double>::epsilon()) { 32 frames_per_second_ = frame_count_ / elapsed_time; 33 } 34 frame_duration_accumulator_ = 0; 35 frame_count_ = 0; 36 } 37 } 38 39 void FrameCounter::Reset() { 40 frames_per_second_ = 0; 41 frame_duration_accumulator_ = 0; 42 frame_count_ = 0; 43 } 44
