let tw = 240;

let th = 240;

​

const colors = [

  // [0, 0, 204],

  // [0, 0, 128],

  // [0, 0, 0],

  [255, 255, 255],

  [250, 250, 250],

  [245, 245, 245],

];

​

function setup() {

  createCanvas(windowWidth, windowHeight);

  noLoop();

}

​

function draw() {

  tw = windowWidth / 3;

  th = windowWidth / 3;

  noStroke();

  for (var x = 0; x < width; x+=tw) {

    for (var y = 0; y < height; y+=th) {

      /* logic for two triangles per box */

      let rand = random();

      drawTriangles(x, y, rand);

    }

  }

}

​

//for splitting squares into two trianges

function drawTriangles(x, y, dir){

  //dir > .5 draws line ul to lr

  //dir < .5 draws line lr to ur

​

  //define triangle points

  let ulx = x;

  let uly = y;

  let llx = x;

  let lly = y + th;

  let urx = x + tw; 

  let ury = y;

  let lrx = x + tw;

  let lry = y + th;

​

  //draw triangles by dir

  if (dir > .5) {

    fill(getColor());

    triangle(ulx, uly, llx, lly, urx, ury);

    fill(getColor());

    triangle(llx, lly, urx, ury, lrx, lry);

  } else if (dir <= .5) {

    fill(getColor());

    triangle(ulx, uly, llx, lly, lrx, lry);

    fill(getColor());

    triangle(ulx, uly, urx, ury, lrx, lry);

  }

}

​

function getColor() {

  let col;

  col = colors[parseInt(random(colors.length))];

  stroke(col);

  return col;

}

​

function setResize() {

  resizeCanvas(windowWidth, windowHeight);

  draw();

}

​

function windowResized() {

  clearTimeout(timer);

  timer = setTimeout(setResize, 100);

}