function setup() {
  createCanvas(windowWidth, windowHeight, WEBGL);
  angleMode(DEGREES);

  noLoop();
}

function draw() {
  background(220);
  // randomSeed(1);

  translate(0, 200, 0);
  rotateY(frameCount)

  branch(random(70, 130))
}


function branch(len) {
  strokeWeight(map(len, 10, 100, 0.5, 5));
  stroke(70, 40, 20);

  line(0, 0, 0, 0, -len - 2, 0);

  translate(0, -len, 0);

  if (len > 10) {
    for (let i = 0; i < 3; i++) {
      rotateY(random(100, 140));

      push();
      rotateZ(20, 50);
      branch(len * 0.77);


      pop();
    }
  } else {

    let r = 180 + random(-20, 20);
    let g = 120 + random(-20, 20);
    let b = 40 + random(-20, 20);

    fill(r, g, b, 200)
    noStroke();

    translate(5, 0, 0);
    rotateZ(90);

    beginShape();
    for (let i = 45; i < 135; i++) {
      let rad = 7;
      let x = rad * cos(i);
      let y = rad * sin(i);
      vertex(x, y);
    }
    for (let i = 135; i > 45; i--) {
      let rad = 7;
      let x = rad * cos(i);
      let y = rad * sin(i) + 10;
      vertex(x, y);
    }
    endShape(CLOSE);
  }
}