// You can find the Turtle API reference here: https://turtletoy.net/syntax
Canvas.setpenopacity(0.5);

// Global code will be evaluated once.
const turtle = new Turtle();
turtle.penup();

const pi = Math.PI;
let rx = 95.0;
let ry = 50.0;

let   ang     = 0.0;
let   step = pi / 180.0;

let freq = 3.0;
let freqMod = 199.0;

// The walk function will be called until it returns false.
function walk(i) 
{
    turtle.penup();
    turtle.goto( rx*Math.sin(ang), ry*Math.cos(ang*freq) + Math.cos(ang*freqMod) );
    
    ang += step;
    
    turtle.pendown();
    turtle.goto( rx*Math.sin(ang), ry*Math.cos(ang*freq) + Math.cos(ang*freqMod) );
    
    
    return ang < pi*20.0;
}