​

function setup() {

  createCanvas(400, 400);

}

​

function draw() {

  background(0, 80);

  // basic fish unit

  sway = sway + 0.1;

  noFill();

  stroke("white");

  beginShape();

  curveVertex(20, 120);

  curveVertex(110, 90 + 5 * sin(sway));

  curveVertex(180, 115 + 5 * cos(sway));

  curveVertex(220, 100);

  curveVertex(240, 70 + 10 * sin(sway));

  endShape();

  beginShape();

  curveVertex(20, 80);

  curveVertex(110, 110 + 5 * sin(sway));

  curveVertex(180, 85 + 5 * cos(sway));

  curveVertex(220, 100);

  curveVertex(240, 130 + 10 * sin(sway));

  endShape();

}