C# Trouble Calculating Delta Time

Question

I am trying to make a timing system in C#, and I am having trouble calculating delta time.

Here is my code:

private static long lastTime = System.Environment.TickCount;
private static int fps = 1;
private static int frames;

private static float deltaTime = 0.005f;

public static void Update()
{
    if(System.Environment.TickCount - lastTime >= 1000)
    {
        fps = frames;
        frames = 0;
        lastTime = System.Environment.TickCount;
    }
    frames++;

    deltaTime = System.Environment.TickCount - lastTime;

}

public static int getFPS()
{
    return fps;
}

public static float getDeltaTime()
{
    return (deltaTime / 1000.0f);
}

The FPS counting is working correctly, but the delta time is faster than it should be.

Answer 1

Value of System.Environment.TickCount changes during the execution of your function which is causing deltaTime to move faster than you expect.

Try

private static long lastTime = System.Environment.TickCount;
private static int fps = 1;
private static int frames;

private static float deltaTime = 0.005f;

public static void Update()
{
    var currentTick = System.Environment.TickCount;
    if(currentTick  - lastTime >= 1000)
    {
        fps = frames;
        frames = 0;
        lastTime = currentTick ;
    }
    frames++;

    deltaTime = currentTick  - lastTime;

}

public static int getFPS()
{
    return fps;
}

public static float getDeltaTime()
{
    return (deltaTime / 1000.0f);
}