I've come across a number of programs that use what I take to be a Processing timer construct, usually initialized like

timer myTimer = new timer(millis());

and then called to output the time between frames in the draw() method.

float dt = myTimer.M_getDelta(millis())/1000;

I can't find any documentation of this function in the processing reference, or the dev javadoc; it doesn't seem to match with java.util.timer, which has no input for millis() and when I search the sun dev site I can't find reference to M_getDelta anywhere..

I'd like to use this method of determining the elapsed time since the last frame in a simple physics library I'm writing for my own use (so, called from within a .java file) .. what do I need to import to do so? processing.core.* doesn't cut it, apparantly.

I was doing some physics simulation work recently and found that having an accurate elapsed time mechanism for the simulation was useful. I did this by making a small class that i would then initialize with the simulation initialization which then kept track of the main object timing.

What Alterscape is talking about looks to me like an object that is doing the same thing. The java.util.Timer is a utility for scheduling thread processes and has a different initialization and methods attached to it (at least in 1.5).

My guess is that the class is just a simple variable that takes the initialization argument and stores it. Then when called it is passed the current time and returns the difference. by dividing by 1000 this gives the seconds elapsed.

my code is:

public class Time implements Cloneable{

private long t;

 public Time(){
  this.t=System.currentTimeMillis();
 }

 public int millis(){
  return (int)(System.currentTimeMillis() - this.t);
 }

 public void resetTime(){
  this.t=System.currentTimeMillis();
 }

 public Object clone(){
    try
       {
       return super.clone();
       }
    catch ( CloneNotSupportedException e )
       {
       return null;
       }
     }
}