Canvas.setpenopacity(1);

let alternating = 0; //min=0, max=1, step=1
let squaresPerRotation = 20; //min=4, max=22, step=2
let offsetPerRotation = .1; //min=0, max=1, step=.1

const turtle = new Turtle();
turtle.setheading(90);

squaresPerRotation += (squaresPerRotation % 2 == 1? 1: 0);

//penstatus = 0 = pen is down;
//penstatus = 1 = pen is up;
var penstatus = 0;
turtle.pendown();

function togglePen() {
    penstatus == 0? turtle.penup(): turtle.pendown();
    penstatus = (penstatus + 1) % 2;
}

var r = 0;
var alternate = 1
// The walk function will be called until it returns false.
function walk(i) {
    var toggle = false;
    if(penstatus == 0) { toggle = true; togglePen(); }
    turtle.circle(i / 8, alternate * offsetPerRotation)
    if(toggle) { togglePen(); }

    if((i / 8) > r) {
        togglePen();
        r = (i / squaresPerRotation) * Math.PI;
        if(alternating) { alternate *= -1; }
    }
    for(var j = 0; j < squaresPerRotation; j++) {
        turtle.circle(i / 8, 360/squaresPerRotation)
        togglePen();
    }

    turtle.left(90);
    turtle.forward(1 / 8);
    turtle.right(90);

    return i < 1200;
}