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std::chrono for FPS setting and counting
I'm working on some experiments on using internally std::chrono for FPS timing inside OF Core. I think we have some advantages as using the same code for all platforms, and maybe having better precision. here is an experiment with a fps counter
#include <chrono>
using namespace std::chrono;
using namespace std::chrono_literals;
struct fpsCounter {
public:
int nAverages = 20;
time_point<steady_clock> lastTick;
using space = std::chrono::duration<long double, std::nano>;
steady_clock::duration onesec = 1s;
vector <space> intervals;
space interval;
space average;
bool firstTick = true;
int cursor = 0;
void tick() {
if (firstTick) {
firstTick = false;
lastTick = steady_clock::now();
return;
}
interval = steady_clock::now() - lastTick;
lastTick = steady_clock::now();
if (intervals.size() < nAverages) {
intervals.emplace_back(interval);
} else {
intervals[cursor] = interval;
cursor = (cursor+1)%nAverages;
}
}
float get() {
// average = std::reduce(intervals.begin(), intervals.end())/intervals.size();
// return onesec / average;
average = std::reduce(intervals.begin(), intervals.end());
return intervals.size() * onesec / average;
}
} count;
it can be used like this
void ofApp::update() {
count.tick();
cout << "fps " << ofGetFrameRate() << endl;
cout << "get " << count.get() << endl;
cout << "---" << endl;
}
