project-swan/libswan/include/swan/Clock.h

#pragma once

#include <string>
#include <chrono>
#include <ostream>

namespace Swan {

class Clock {
public:
	void tick(float dt) { time_ += dt; }
	void reset() { time_ = 0; }
	float duration() { return time_; }
	bool periodic(float secs);

private:
	float time_ = 0;
};

class RTClock {
public:
	void reset() {
		start_ = std::chrono::steady_clock::now();
	}

	double duration() const {
		return std::chrono::duration<double>(
			std::chrono::steady_clock::now() - start_).count();
	}

	friend std::ostream &operator<<(std::ostream &os, const RTClock &clock) {
		double dur = clock.duration();
		if (dur > 1)
			os << dur << 's';
		else
			os << dur * 1000.0 << "ms";
		return os;
	}

private:
	std::chrono::time_point<std::chrono::steady_clock> start_ =
		std::chrono::steady_clock::now();
};

}