​

function setup() {

  // put setup code here

  createCanvas(windowWidth, windowHeight);

  noStroke();

}

​

function draw() {

  // put drawing code here

  background(255);

  fill(50);

​

  for (let i = 0; i < windowWidth; i += size * 2) {

    for (let j = 0; j < windowHeight; j += size * 2) {

      drawRect(i, j);

      drawBorder1(i + size, j);

      drawBorder2(i, j + size);

    }

  }

}

​

// rect

function drawRect(x, y) {

  push();

  translate(x, y);

  rect(0, 0, size, size);

  pop();

}

function drawBorder1(x, y) {

  push();

  translate(x, y);

  triangle(0, 0, size / 3, 0, 0, size / 3);

  quad(size, 0, size, size / 2, size / 2, size, 0, size);

  pop();

}

​

function drawBorder2(x, y) {

  push();

  translate(x, y);

  quad(size / 2, 0, size, 0, 0, size, 0, size / 2);

  //quad(size, 0, size, size / 2, size / 2, size, 0, size);

  triangle(size, (size / 3) * 2, size, size, (size / 3) * 2, size);

  pop();

}

​