charcoal/OpenGLEngine/FPS.h

#pragma once

#include <ctime>

//A class to handle the FPS of the game
//Calculations are done per the number of frames specified
//Frames must be a value from 2 - 255
//Recommended numbers for frames is 2 (Instant), 5 (Slightly Smoothed), 60 (Smoothed)
//Max number for frames = 255
//Lower frames = jumpy, instant updates
//Higher frames = smoother, flowing updates
class FPS final
{
public:
	FPS(unsigned short frames = 2);
	~FPS();

	//Returns the clock of the last mark() call
	const clock_t& get_clock() const;

	//Returns FPS (frames per second) of the game (based on the last marked frame)
	//CLOCKS_PER_SECOND / (m_clock - m_prevClock)
	float get_spf() const;

	//Returns FPS (frames per second) of the game (based on the last marked frame)
	//CLOCKS_PER_SECOND / (m_clock - m_prevClock)
	float get_fps() const;

	//Fills the clocks with the current clock() value (to prevent unreasonable clock counts at the first few frames)
	void prepare();

	//Marks the end of the frame (resets the clock)
	//Should be called right before the update() and render() functions 
	//Also calculates the seconds per frame (able to be considered the dTime)
	//(m_clock - m_prevClock) / CLOCKS_PER_SEC
	float mark();

private:
	//m_iter marks the place of the next mark
	unsigned short m_iter;
	unsigned short m_frames;

	clock_t* m_clocks = nullptr;
};