Buttonクラス

Button b1;
Button b2;
Button b3;
void setup() {
  background(0);
  size(1600, 1600);
  b1= new Button("タイトル1", "リンク1");
  b2= new Button("タイトル2", "リンク2");
  b3= new Button("タイトル3", "リンク3");
}
void draw() {
  b1.open();
  b2.open();
  b3.open();
  b1.render();
  b2.render();
  b3.render();
}

class Button {
  float x, y, vX, vY, r;
  color c;
  String title, web;
  Button(String title, String web) {
    x = random(width/4, width*3/4);
    y= random(height/4, height*3/4);
    r = random(width / 3, width/2);
    c = color(random(100, 200), random(100, 200), 10);
    this.title = title;
    this.web = web;
  }
  void open() {
    if (dist(x, y, mouseX, mouseY) < r/2) {
      if (mousePressed) {
        link(web);
        x = 0;
        y = 0;
        r = 0;
      }

      vX = (mouseX - x)/dist(x, y, mouseX, mouseY)*2;
      vY = (mouseY - y)/dist(x, y, mouseX, mouseY)*2;

      if (r >10) {
        r -= 3;
      }
    } else {
      vX = 0;
      vY = 0;
      if (mousePressed) {
        x = random(width/4, width*3/4);
        y = random(height/4, height*3/4);
        r = random(width/3, width*2/3);
      }
    }
  }
  void render() {
    x += vX;
    y += vY;
    fill(red(c), green(c), blue(c), 10);
    ellipse(x, y, r, r);
    fill(255-red(c), 255-green(c), 255-blue(c));
    textSize(r/4);
    text(title, x - title.length()*r/8, y);
  }
}