class Ex {
  float x, y, w, speed, a;

  Ex (float x_, float y_, float w_, float speed_, float a_) {
    x = x_;

    y = y_;

    w = w_;
    speed = speed_;   
    a = a_;
  }

  void displayx () {
    noStroke ();
    fill (126,0,255, a);
    ellipse (x,y,w,w);
  }

  void movex () {
          if (random(1.0) < 0.5) {
x -= speed;
y +=speed*0.5;
          }
                if (random(1.0) > 0.5) {
x -=speed;
y -=speed;
                }
        
    x  = x + random( - 10,10);
    y  = y + random( - 10,10);

    x = constrain (x,0,width);
        y = constrain (y,0,height);
    
    a  = a + 2 * speed;
    if (a > 100) {
      a-=40; 
    }
    else if (a < 20) {
      a+=40;
    }
  }

  void bouncex () {
    if ( y < 1 ||  y> (height-1) || x < 1 || x > (width-1)) {
      speed = speed * -0.95;
    }
      if ( x < 600 ) {
      speed = speed *-1;
    }

    if (buttonx) {
      if (random(1.0) < 0.02) {

        Ex xs = new Ex (random(750,790), random(420,470), random(2,5), random(7), random (150,70));
        exes = (Ex []) append (exes, xs); 
      }
    }
  }
}