​

function drawCell(x, y, np, coff, off) {

  let pts = [];

  let xs = [];

  let ys = [];

  for (let _y = y+coff; _y < y+off; _y += coff) {

    ys.push(_y)

  }

  for (let _x = x+coff; _x < x+off; _x += coff) {

    xs.push(_x);

  }

  for (let i = 0; i < xs.length; i++) {

    pts.push({x: xs[i], y: y, done: false});

    pts.push({x: xs[i], y: y+off, done: false});

  }

  for (let i = 0; i < ys.length; i++) {

    pts.push({x: x, y: ys[i], done: false});

    pts.push({x: x+off, y: ys[i], done: false});

  }

  done = false;

  while (!done) {

    let plen = pts.filter((pt) => pt.done);

    if (plen.length == pts.length) {

      done = true;

      break;

    }

    let pt1 = random(pts);

    let pt2 = random(pts);

    while (pt1 == pt2 || pt1.x == pt2.x || pt1.y == pt2.y) {

      pt2 = random(pts);

    }

    pt1.done = true;

    pt2.done = true;

    line(pt1.x, pt1.y, pt2.x, pt2.y);

  }

}

function setup() {

  createCanvas(1800, 1800);

  background(20);

  stroke(color(220,220,220,80));

  strokeWeight(1);

  pixelDensity(1);

  let off = width * 0.01;//1;

  for (let y = off; y < height; y += off) {

    line(0, y, width, y);

  }

  for (let x = off; x < width; x += off) {

    line(x, 0, x, height);

  }

  stroke(220);

  let npts = 2;

  let coff = off / npts;

  for (let y = off; y < height-off; y += off) {

    for (let x = off; x < width-off; x += off) {

      drawCell(x, y, npts, coff, off);

    }

  }

  noFill();

  strokeWeight(2);

  rect(off, off, width-2*off, height-2*off);

  // drawCell(off, off, npts, coff, off);

}

​

function draw() {

  // background(220);

}