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

// inspired by https://direct.mit.edu/books/oa-monograph/4663/Turtle-GeometryThe-Computer-as-a-Medium-for
// Turtle Geometry: The Computer as a Medium for Exploring Mathematics 
// Harold Abelson, Andrea diSessa
// The MIT Press
// DOI: https://doi.org/10.7551/mitpress/6933.001.0001
// ISBN electronic: 9780262362740
// Publication date: 1981

// Global code will be evaluated once.
const turtle = new Turtle();
const n = 9; //min=9 max=39 step=1
const scale = 7; // min=1 max=8 step=1

const angle = 90; 
const index = 0;
var count = 0;
turtle.penup();
turtle.goto(-30,-30);
turtle.pendown();

// The walk function will be called until it returns false.
function walk(i) {
    subgspiro(scale,angle,n, 3, 4, 5);
    i++;
    return i < n;
}

function subgspiro (side, angle, max, a, b, c ){
    count = 1;
    turtle.pendown();
    
    for (var i = 0; i < max; i++) {
        step = side * count;
        turtle.forward(step);
        if((count == a) || (count == b) || count==c){
            turtle.left(angle);   
        }
        else{
            turtle.right(angle);
        }
        count ++;
    }
}