wk01_paperTexture.js

  const drawPaperTexture = (x, y, w, h) => {
    let cx, cy, rng, cs;
    rng = 100;
    push();
    translate(x, y);
    let a = (w + h) * 4;
    for (let i = 0; i < a; i++) {
      noStroke();
      fill(255, R() * 255);
      cs = R() * 3;
      ellipse(R() * w, R() * h, cs, cs);

      noFill();
      if (R() < 0) {
        stroke(255, R() * 150);
        beginShape();
        cx = R() * w;
        cy = R() * h;
        curveVertex(cx, cy);
        curveVertex(cx + rng * R() * sn(), cy + rng * R() * sn());
        cx = R() * w;
        cy = R() * h;
        curveVertex(cy + rng * R() * sn(), cy + rng * R() * sn());
        curveVertex(cx + rng * R() * sn(), cy + rng * R() * sn());
        endShape();
      }
    }
    pop();
  };