uses the concept of Probability

*/

let x = 0, y = 0, sp = 10;

function setup() {

  createCanvas(400, 400);

  background(0);

}

​

function draw() {

  stroke(255);

  if(random(1) < 0.5) {

    line(x, y, x + sp, y + sp);

  }

  else {

    line(x, y + sp, x + sp, y);

  }

  x = x + sp;

  if(x > width) {

    x = 0;

    y = y + sp;

  }

}

​