​

let angle;

​

let slider;

​

function setup() {

  createCanvas(400, 400);

  print("go");

  len = height / 4;

  slider = createSlider(0, TWO_PI, PI / 4, 0.01);

}

​

function draw() {

  background(200);

  // 단위: radian (1 PI radian = 180 degree)

  angle = slider.value();

  // translate()하면 drawing위치가 아예 고정됨

  translate(width / 2, height);

  branch(len);

}

​

function branch(len) {

  if(len <= 3) {

    return;

  }

  line(0, 0, 0, -len);

  translate(0, - len);

  // recursive function

  push();

  rotate(angle);

  branch(len * (2/3));

  pop();

  push();

  rotate(-angle);

  branch(len * (2/3));

  pop();

}

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​