Example #1
0
    /** Internal routine for generating the List of particles on collision. */
    public static ArrayList<Particle> generateParticles(Ball ball, Body body) {
      double centerX = ball.getCenter().x();
      double centerY = ball.getCenter().y();

      double speed =
          ball.getVelocity().magnitude() * ((body != null) ? (body.getRadius() / 100.0) : 1);

      if (speed < .50) speed = .50;
      if (speed > 2.50) speed = 2.50;
      if (body != null) {
        double max = Math.pow(body.getRadius() + ball.getRadius(), 2);
        while (body.getCenter().distanceSquared(new Point2d(centerX, centerY)) < max) {
          centerX -= ball.getVelocity().xComponent();
          centerY -= ball.getVelocity().yComponent();
        }
      }

      ArrayList<Particle> particles = new ArrayList<Particle>();
      int num = (int) (300 * speed);
      if (num < 150) num = 150;
      else if (num > 400) num = 400;

      for (int i = 0; i < num; i++) {
        double angle = (Math.random() * 2 * Math.PI);
        double xSpeed = 0.75 * (Math.random() * speed * Math.cos(angle));
        double ySpeed = 0.75 * (Math.random() * speed * Math.sin(angle));

        Color c;
        double rand = Math.random();
        if (body == null) c = CalcHelp.getShiftedColor(ball.getColor(), 100);
        else if (rand < 0.3) c = CalcHelp.getShiftedColor(body.getColor(), 100);
        else if (rand < 0.40) c = CalcHelp.getShiftedColor(new Color(230, 130, 70), 100);
        else c = CalcHelp.getShiftedColor(ball.getColor(), 100);

        Particle newParticle = new Particle(centerX, centerY, xSpeed, ySpeed, c);
        particles.add(newParticle);
      }

      return particles;
    }