#include "FPS.h"
#include <QTimer>

FPS::FPS() {
	previousFrame = system_clock::now();
	timeSinceUpdate = nanoseconds(0);
	framesSinceUpdate = 0;
	current = 0;

	timer = new QTimer(this);
	timer->setInterval(250);
	connect(timer, &QTimer::timeout, this, &FPS::updateCurrent);
	timer->start();
}

void FPS::newFrame() {
	framesSinceUpdate++;
	auto thisFrame = system_clock::now();
	timeSinceUpdate += thisFrame - previousFrame;
	previousFrame = thisFrame;
}

void FPS::setUpdateInterval(int milli) {
	timer->setInterval(milli);
}

void FPS::updateCurrent() {
	if (timeSinceUpdate.count() == 0)
		current = 0;
	else
		current = framesSinceUpdate * 1000 * 1000 * 1000 / (timeSinceUpdate.count());
	framesSinceUpdate = 0;
	timeSinceUpdate = nanoseconds(0);
}