Coches que se chocan con una bola

boolean r, l, d, u;

float x = 50, y = 50;

int numcoches = 30; 

 int xbola=30;

 int ybola=30;

Car[] cars = new Car[numcoches];  // Declaramos el arreglo de coches

void setup() {

  size(800, 800);

  frameRate(80); 

  for (int i = 0; i < numcoches; i++) {

    cars[i] = new Car(color(random(255), random(255), random(255)), random(10, width - 10), random(10, height - 10), random(-5, 5));

  }

}

void draw() {

  background(0);

  ellipse(x, y, xbola, ybola);

  if (r) x += 1;

  if (l) x -= 1;

  if (u) y -= 1;

  if (d) y += 1;

  for (int i = 0; i < numcoches; i++) {

    cars[i].drive();

    if(dist(x,y,cars[i].xpos,cars[i].ypos )<27){

    noLoop();

  }

    cars[i].display();

  }

}

void keyPressed() {

  if (keyCode == RIGHT) r = true;

  if (keyCode == LEFT) l = true;

  if (keyCode == UP) u = true;

  if (keyCode == DOWN) d = true;

}

void keyReleased() {

  if (keyCode == RIGHT) r = false;

  if (keyCode == LEFT) l = false;

  if (keyCode == UP) u = false;

  if (keyCode == DOWN) d = false;

}

class Car {

  color c;

  float xpos;

  float ypos;

  float xspeed;

  Car(color tempC, float tempXpos, float tempYpos, float tempXspeed) {

    c = tempC;

    xpos = tempXpos;

    ypos = tempYpos;

    xspeed = tempXspeed;

  }

  void display() {

    stroke(0);

    fill(c);

    rectMode(CENTER);

    rect(xpos, ypos, 20, 10);

  }

  void drive() {

    xpos += xspeed;

    if (xpos > width) {

      xpos = 0;

    }

    if (xpos < 0) {

      xpos = width;

    }

  }

}