simple high resolution timer w/SDL2

timer.h

/* USAGE:
 * Timer foo; // Start the timer
 * const TimeData &time = foo.touch(); // Update and return TimeData (delta being the time since last touch)
 * const TimeData &time_peek = foo.peek(); // returns current TimeData only updating the current time (does not reset!)
 * SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION
 *
 * I haven't actually tested peek, but it looks right... */

#pragma once
#include <SDL.h>

struct TimeData {
	Uint64 then;
	Uint64 now;
	Uint64 frequency;
	double delta;
};

class Timer {
public:
	Timer() {
		m_time.now = SDL_GetPerformanceCounter();
		m_time.then = m_time.now;
		m_time.frequency = SDL_GetPerformanceFrequency();
	}
	// Note: delta is since last touch OR peek
	const TimeData &touch() {
		m_time.then = m_time.now;
		m_time.now = SDL_GetPerformanceCounter();
		m_time.delta = double(m_time.now - m_time.then) / double(m_time.frequency);

		return m_time;
	}
	// Note: delta is since last touch
	const TimeData &peek() {
		m_time.now = SDL_GetPerformanceCounter();
		m_time.delta = double(m_time.now - m_time.then) / double(m_time.frequency);
		return m_time;
	}

protected:
	TimeData m_time;
};