registerDraw

package com.danbrookes.main;

import java.util.ArrayList;
import processing.core.*;

public class Base extends PApplet {

    private static final long serialVersionUID = -7052994455601885135L;
    private ArrayList<TestObject> list = new ArrayList<TestObject>();
    private PApplet app = this;
    private int amount = 2500;
    private float rnd;
    private float ms;

    // main
    public static void main(String[] args) {
        PApplet.main(new String[] {Base.class.getName()});
    }

    // setup
    @Override
    public void setup() {
        size(640, 360);
        frameRate(60);
        fill(255, 128);
        strokeWeight(1);
        stroke(0, 128);
        textSize(48);
        smooth();
        for (int i = 0; i < amount; i++) {
            rnd = random(10);
            list.add(new TestObject(app, random(width), random(height), rnd, rnd));
        }
    }

    // draw
    @Override
    public void draw() {
        background(255);
        fill(0, 64);
        ms = millis();
        for (int i = 0; i < amount; i++) {
            list.get(i).setPos(list.get(i).getX() + random(-2,2), list.get(i).getY() + random(-2,2));
        }
        fill(255,0,0);
        text(millis() - ms + "", 10, 10, 200, 200);
    }
}

---------------------------------------------

package com.danbrookes.main;

import processing.core.*;

public class TestObject {

    private PApplet pro;
    private float x;
    private float y;
    private float w;
    private float h;

    public TestObject(PApplet processing, float tX, float tY, float tW, float tH) {
        pro = processing;
        pro.registerDraw(this);
        x = tX;
        y = tY;
        w = tW;
        h = tH;
    }

    public void draw() {
        pro.ellipse(x, y, w, h);
    }

    public void setPos(float x, float y) {
        this.x = x;
        this.y = y;
    }

    public float getX() {
        return x;
    }

    public float getY() {
        return y;
    }

    public void setScale(float w, float h) {
        this.w = w;
        this.h = h;
    }

    public float getW() {
        return w;
    }

    public float getH() {
        return h;
    }
}