Timer using frameRate and frame counter reliable?

问题

I'm using p5js to program an animation with a timer countdown. I set my timer up to be updated each frame within an object that is being animated by the draw() function in sketch. Because of this, setInterval() will not work for what I'm trying to do.

I thought I could use the frameRate and a frame counter to decide if a second has passed:

this.updateTimer = function(){
  this.framecounter++;
  if(this.framecounter > frameRate()){
    this.framecounter = 0;
    //increment seconds
  }
}

Is this reliable? I tested it against an actual timer and it seems to be about 1 second ahead after about 15 seconds. Is there a better way to do this by calling a function each frame? Thanks!

回答1:

Why don't you just use the frameCount variable? More info is available in the reference.

You could also use the millis() function instead. Again, the reference is your best friend.

If you still can't get it working, please post a MCVE (or better yet, a CodePen or JSFiddle) that we can run to see the problem.

来源：https://stackoverflow.com/questions/44666511/timer-using-framerate-and-frame-counter-reliable