Random Smoke

var np = 300;

var startcol;

​

function setup()

{

  createCanvas(1000,1000);

  background(0);

  blendMode(ADD);

  noFill();

  noiseSeed(random(100));

  startcol = random(255);

}

​

function draw()

{

  beginShape();

  for (var i=0; i<np; i++) {

    var angle = map(i, 0, np, 0, TWO_PI);

    var cx = frameCount * 2 - 200;

    var cy = height / 2 + 50 * sin(frameCount / 50);

    var xx = 100 * cos(angle);

    var yy = 100 * sin(angle);

    var v = createVector(xx, yy);

    xx = (xx + cx) / 150;

    yy = (yy + cy) / 150;

    v.mult(1 + 1.5 * noise(xx,yy));

    vertex(cx+v.x, cy+v.y);

    if(i == 0) {

        sx = cx + v.x;

        sy = cy + v.y;

    }

  }

  colorMode(HSB);

  var hue = cx / 10 - startcol;

  if (hue < 0) hue += 255;

  stroke(hue,100,100);

  strokeWeight(0.2);

  vertex(sx, sy);

  endShape();

}