Having an event occur every n milliseconds ?

zooto68

I would like a function to run every n milliseconds, regardless of what else is going on in the program. Similar to an interrupt driven function in Arduino language. Is there any way to do that in processing?

Thanks,

Mike

GoToLoop

Using "official" Processing API only we can't. But w/ Java bundled libraries, sure! :-bd
http://docs.Oracle.com/javase/8/docs/api/java/util/TimerTask.html

/** 
 * TimerTask (v1.3)
 * by GoToLoop (2013/Dec)
 * 
 * forum.Processing.org/two/discussion/1725/millis-and-timer
 * docs.Oracle.com/javase/8/docs/api/java/util/TimerTask.html
 */

import java.util.Timer;
import java.util.TimerTask;

final Timer t = new Timer();
boolean hasFinished = true;

void draw() {
  if (hasFinished) {
    final float waitTime = random(10);
    createScheduleTimer(waitTime);
    println("\n\nTimer scheduled for " + nf(waitTime, 0, 2) + " secs.\n");
  }

  if ((frameCount & 0xF) == 0)   print('.');
}

void createScheduleTimer(final float sec) {
  hasFinished = false;

  t.schedule(new TimerTask() {
    public void run() {
      print(" " + nf(sec, 0, 2));
      hasFinished = true;
    }
  }
  , (long) (sec*1e3));
}

GoToLoop

A simpler approach relying on thread("") + delay() to execute a task after a specified time continually:
http://Processing.org/reference/thread_.html

// forum.processing.org/two/discussion/8467/a-quick-question-about-screenshots

static final int FPS = 60, INTERVAL = 5 * 1000; // 5 seconds

void setup() {
  size(300, 200, JAVA2D);
  frameRate(FPS);
  thread("timedShots");
}

void draw() {
  background((color) random(#000000));
}

void timedShots() {
  for (;; delay(INTERVAL))  saveFrame(dataPath("####.jpg"));
}