​

const colors = [

  [0, 0, 204],

  [0, 0, 128],

  [0, 0, 0],

];

​

let tw = 180;

let th = 180;

​

function setup() {

  createCanvas(640, 640);

  // noLoop();

}

​

function draw() {

  if (millis() - timestamp > 2000) {

    timestamp = millis();

    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;

}