GameTime.ElapsedTime.Milliseconds is 0 at high fps

1

Hi!

I am currently re-writing my “extension code base” (would not call it engine :smile:) and I am testing my AnimatedSprite class. In its Update method, I am tracking the elapsed time by adding the gameTime.ElapsedTime.Milliseconds to a private float variable, and when it reaches a specific amount I play the next frame. It works fine at 60 fps, but at the moment I only display 2 test animation and the fps is around 3500. :smiley: Therefore the ElapsedTime.Milliseconds is always 0, so I am adding 0 to the variable, so it remains 0, therefore the animation does not even start.

My question: although I am happy with the 60fps settings, but is there a “better” way to track the elapsed time?

2

Delta time?

Why are you tying your timing to your FPS?

I might be confused with what you wrote but to me it sounds as if you are doing it that way…

Isolate your timing code and post it so someone can look at it.

3

Use a TimeSpan to track time. ex.:
TimeSpan t;
// in update
t+=gameTime.ElapsedTime;

Or use TimeSpan.Ticks. One tick is 1/10000ms or something, it might be platform-specific.
TimeSpan wraps this number and convert it to/from Minutes/Seconds/msecs/etc.
There are all the overloads you need to add/sub between TimeSpan and DateTime.

4

Use the TotalSeconds or TotalMilliseconds properties, since they count whole and fractional parts. The Milliseconds property only counts whole milliseconds. 3500fps means 1/3500 sec per frame. That is less than 1 ms which is 1/1000 sec, and since the Milliseconds property is an integer, it gets rounded down to zero. The TotalMilliseconds property will return the fractional part of the millisecond as well.

1 Like
5

Thanks, I tried it and works fine with all settings. This is now how I “calculate” when do I need to show the next frame:

float AnimationTimer = 0.0f;
...

public void Update(...)
{
   //CurrentAnimation.DelayUntilNextFrame = the delay in milliseconds between
   //the current frame and the next one.
   if (AnimationTimer < CurrentAnimation.DelayUntilNextFrame)
       AnimationTimer += (float)(gameTime.ElapsedGameTime.TotalMilliseconds %
                              CurrentAnimation.DelayUntilNextFrame);
   else
   {
       AnimationTimer = 0.0f;
       //Show next frame...
   }
}