core/elapsedtimer: add ElapsedTimer

src/core/elapsedtimer.cpp

@@ -0,0 +1,22 @@
+#include "elapsedtimer.hpp"
+
+#include <qtypes.h>
+
+ElapsedTimer::ElapsedTimer() { this->timer.start(); }
+
+qreal ElapsedTimer::elapsed() { return static_cast<qreal>(this->elapsedNs()) / 1000000000.0; }
+
+qreal ElapsedTimer::restart() { return static_cast<qreal>(this->restartNs()) / 1000000000.0; }
+
+qint64 ElapsedTimer::elapsedMs() { return this->timer.elapsed(); }
+
+qint64 ElapsedTimer::restartMs() { return this->timer.restart(); }
+
+qint64 ElapsedTimer::elapsedNs() { return this->timer.nsecsElapsed(); }
+
+qint64 ElapsedTimer::restartNs() {
+	// see qelapsedtimer.cpp
+	auto old = this->timer;
+	this->timer.start();
+	return old.durationTo(this->timer).count();
+}