FPS Counter

FpsCounter.cs

using System.Diagnostics;

public sealed class FpsCounter
{
    double currentFps;
    long lastFrameTime;
    const float SmoothFactor = 0.1f;

    public FpsCounter() => Reset();

    public double Current => Math.Round(currentFps, 2);

    public void Update()
    {
        var delta = Stopwatch.GetElapsedTime(lastFrameTime);
        Update(delta.TotalSeconds);
        lastFrameTime = Stopwatch.GetTimestamp();
    }

    void Update(double deltaTime)
    {
        var newFps = 1 / deltaTime;
        currentFps = ((1 - SmoothFactor) * currentFps) + (SmoothFactor * newFps);
    }

    public void Reset()
    {
        currentFps = FrameRate.ExpectedFps;
        lastFrameTime = Stopwatch.GetTimestamp();
    }
}