eric e. dolecki

Interactive Technologist and Designer

Gritfish's TrueTimer class is something that attempts to tackle the inaccuracy of the built-in Timer class. Run over and read his post and see the class, or you can check it out here as well. I have not yet implemented this in anything, it seems that when you receive a Timer event, you're going to have to read the classes public variables instead of getting them from the Timer event object itself. Which is fine I guess.



A quick use example (make sure your listener method is using type of Event and not TimerEvent though - I ran into that myself for a minute).

var myTimer:TrueTimer = new TrueTimer( 100, 100 );
myTimer.addEventListener( TimerEvent.TIMER, onMyTimer );

function onMyTimer( e:Event ):void {
    //you can't use the e.currentTarget.currentCount or anything like that
    trace( myTimer.currentCount );
}

And here is the base class itself:

package {
 import flash.display.*
 import flash.events.*
 import flash.utils.*
 public class TrueTimer extends MovieClip {
  public var delay:int
  public var repeatCount:int
  public var initTime:Date
  public var currentTime:Date
  public var currentCount = 0
  public var __offset:int = 0
  public var running:Boolean = false
  public var timeFromStart = 0
  public var timeShouldBe = 0
  
  public function TrueTimer(DELAY,REPEAT){
   delay = DELAY
   repeatCount = REPEAT
   
   initTime = new Date()
   currentTime = initTime
  }
  public function evaluateTime(e:Event){
   var now = new Date()
   var msDiff = now.valueOf() - currentTime.valueOf()
   __offset += msDiff
   currentTime = now
   if(__offset > delay){
    while(__offset > delay){
     currentCount ++
     __offset -= delay
     
     if(repeatCount != 0){
      if(currentCount == repeatCount){
       timeFromStart = now.valueOf() - initTime.valueOf()
       timeShouldBe = (repeatCount*delay)
       dispatchEvent(new Event(TimerEvent.TIMER))
       dispatchEvent(new Event(TimerEvent.TIMER_COMPLETE))
       __stop()
      }else if(currentCount < repeatCount){
       timeFromStart = now.valueOf() - initTime.valueOf()
       timeShouldBe = (repeatCount*delay)
       dispatchEvent(new Event(TimerEvent.TIMER))
      }
     }else{
      timeFromStart = now.valueOf() - initTime.valueOf()
      timeShouldBe = (repeatCount*delay)
      dispatchEvent(new Event(TimerEvent.TIMER))
     }
    }
   }
  }
  public function __start(){
   initTime = new Date()
   currentTime = initTime
   running = true
   addEventListener(Event.ENTER_FRAME,evaluateTime)
  }
  public function __stop(){
   running = false
   removeEventListener(Event.ENTER_FRAME,evaluateTime)
  }
  public function __clear(){
   currentCount = 0
   __offset = 0
   running = false
   removeEventListener(Event.ENTER_FRAME,evaluateTime)
  }
 }
}

Labels: AS3, Timer Class

 

I've just bit into some weirdness. I have a Timer that I want to fire every 100th of a second. So it would be new Timer( 10, x ); However when testing this isn't not accurate (I am printing the time to the screen). So if I drop the Timer down to fire every 7ms instead of 10, it aligns with my watch, my computer, and my stop watch on my iPhone.

That's great, but what when I move this to another machine? It will probably be slightly off.

What is even stranger is that when I do new Timer( 7, 1800 ); - it still reaches 18 seconds, even though it should have fired a complete before that.

Is there a really accurate way of timing something as close to possible? I know this is a pretty old topic, maybe someone has found something really reliable.

[July 10th Update]

Labels: Timer Class