createCanvas(400, 400);

  colorMode(HSB);

}

​

function draw() {

  background(0);

  let xinc = 5;

  let yinc = 6;

​

  beginShape();

  let count = 0;

​

  for (let x = 0; x < width; x += xinc) {

    let h = (map(x, 0, height, 0, 360) + frameCount) % 360;

    //line(x, 0, x, height);

    if (count % 3 == 0) {

      vertex(x, 0);

    } else if (count % 4 == 0) {

      vertex(x, height);

    } else if (count % 5 == 0) {

      vertex(0, x);

    }

    count++;

  }

​

​

  for (let y = 0; y < height; y += yinc) {

    let h = (map(y, 0, height, 0, 360) + frameCount) % 360;

    stroke(h, 255, 255);

    strokeWeight(4);

    //line(0, y, width, y);

    if (count % 3 == 0) {

      vertex(0, y);

    } else if (count % 4 == 0) {

      vertex(width, y);

    } else if (count % 5 == 0) {

      vertex(y, 0);

    }

​

    count++;

  }

  endShape();

}

​