Ball[] myBalls;

void setup()
{
  size(500,500);
  frameRate(25);

  myBalls = new Ball[300];
  for (int i = 0; i < 300; i++) {
    myBalls[i] = new Ball();
    myBalls[i].x = random(0, 500);
    myBalls[i].y = random(0, 500);
    myBalls[i].r = random(0, 10);
    myBalls[i].xv = random(-5, 5);
    myBalls[i].yv = random(-5, 5);
    myBalls[i].mycolor = int(random(0, 100));
    myBalls[i].myseed = int(random(25,100));
  }
}

void draw() {
  background(0);
  for (int i = 0; i < 300; i++) {
    myBalls[i].run();
  }
}

class Ball
{
  float x; //X acis centroid
  float y; //Y axis centroid\
  float r; // Radius
  float xv; //X axis velocity
  float yv; //Y axis velocity
  int mycolor;
  int myseed;
  int counter;

  void run()
  {
    drawShape();

    x += xv;
    y += yv;

    yv += 0.4;

    if(x < 0 || x > width) {
      xv = -xv;
    }
    else if(y < 0 || y > height) {
      yv = -1.1 * yv;
    }

    if(counter % myseed == 0) {
      xv = random(-5,5);
      yv = random(-5,5);
    }
    counter++;
  }

  void drawShape()
  {
    smooth();
    ellipseMode(CENTER_RADIUS);
    noStroke();
    fill(mycolor);
    ellipse(x,y,r,r);
  }
}