// You can find the Turtle API reference here: https://turtletoy.net/syntax
Canvas.setpenopacity(-1);

const turtle = new Turtle();
turtle.penup();

function divide(x, y, w, h) {
	if (w < 2) return false;
	box(x - w * 0.25, y - w * 0.25, w * 0.5);
	box(x + w * 0.25, y - w * 0.25, w * 0.5);
	box(x - w * 0.25, y + w * 0.25, w * 0.5);
	box(x + w * 0.25, y + w * 0.25, w * 0.5);
	return true;
}

// box rules
function box(x, y, w) {
	const r = Math.random() * 3.6;
	switch (true) {
		case r < 0.1:
			break;
		case r < 0.5:
			divide(x, y, w * 0.5);
			break;
		case r < 2.4:
			divide(x, y, w);
			break;
		default:
			square(x, y, w * 0.8);
	}
}

// draw square
function square(x, y, w) {

	for (let i = w; i > w * 0.8; i -= 0.2) {
	    const r = i * 0.5;
	    turtle.goto(x - r, y - r);
        turtle.down();
    	turtle.goto(x + r, y - r);
    	turtle.goto(x + r, y + r);
    	turtle.goto(x - r, y + r);
    	turtle.goto(x - r, y - r);
	}
	turtle.up();
}

// go
divide(0, 0, 180, 180);