Ghost Tail Vanish

//Use this code from Ben as an array, to create a cluster of dots to simulate smoke!

​

int num = 200;

float[] xs = new float[num];

float[] ys = new float[num];

PVector spd;

void setup() {

  size(640, 950);

  for (int i = 0; i<xs.length; i++) {

    xs[i] = width/2;

    ys[i] = height/2;

  }

  spd = PVector.random2D();

  spd.mult(6);

  noStroke();

}

​

void draw() {

  background(0);

​

  for (int i = xs.length-1; i>0; i--) {

    fill(255, map(i, xs.length, 0, 0, 100));

    ellipse(xs[i], ys[i], 20, 20);

    xs[i] = xs[i-1];

    ys[i] = ys[i-1];

  }

  xs[0] += spd.x;

  ys[0] += spd.y;

  spd.rotate( map(noise(millis()*.01), 0, 1, radians(-10), radians(10)) );

  //println(positions);

  //println("-----------------------");

  if (xs[0] > width) {xs[0] = 0;}

  if (xs[0] < 0) {xs[0] = width;}

  if (ys[0] > height) {ys[0] = 0;}

  if (ys[0] < 0) {ys[0] = height;}

}