### Simplex Noise + SQUARES + lines

Forked Simplex noise to add some extra stuff.

```// Forked from "Simplex Noise" by reinder
// https://turtletoy.net/turtle/6e4e06d42e

// Simplex Noise. Created by Reinder Nijhoff 2020 - @reindernijhoff
// The MIT License
//
// https://turtletoy.net/turtle/6e4e06d42e
// Added some stuff

const turtle = new Turtle();

const frequency = 3; //min=.1, max=10, step=.01
const grid = 50; // min=10, max=100, step=1
const seed = 1; // min=1, max=100, step=1
const noise = new SimplexNoise(seed);

function drawSquare(x, y, size) {
// Draw the square
turtle.jump(x - size / 2, y - size / 2);
turtle.pendown();
for (let i = 0; i < 4; i++) {
turtle.forward(size);
turtle.right(90);
}
turtle.penup();
}

function drawCircle(x, y, size) {
// Draw the circle
turtle.jump(x, y - size / 2);
turtle.pendown();
for (let i = 0; i < 360; i++) {
turtle.forward(Math.PI * size / 180);
turtle.right(1);
}
turtle.penup();
}

function drawLineBehindShape(x, y, size) {
// Randomly decide if the line is vertical or horizontal
const isVertical = Math.random() > 0.5;
const lineLength = size + Math.random() * 6 - 3; // Line length between (size - 3) and (size + 3)

if (isVertical) {
// Draw vertical line
turtle.jump(x, y - lineLength / 2);
turtle.pendown();
turtle.goto(x, y + lineLength / 2);
} else {
// Draw horizontal line
turtle.jump(x - lineLength / 2, y);
turtle.pendown();
turtle.goto(x + lineLength / 2, y);
}
turtle.penup();
}

function walk(i) {
const x = (i % grid) * 200 / grid - 100;
const y = ((i / grid) | 0) * 200 / grid - 100;

const r = 0.5 + 0.5 * noise.noise2D([x * frequency / 200, y * frequency / 200, 0.5]);
const size = r * 100 / grid;

drawLineBehindShape(x + 100 / grid, y + 100 * (1 - r) / grid, size);

// Randomly decide whether to draw a square or a circle
if (Math.random() > 0.5) {
drawSquare(x + 100 / grid, y + 100 * (1 - r) / grid, size);
} else {
drawCircle(x + 100 / grid, y + 100 * (1 - r) / grid, size);
}

return i < grid * grid - 1;
}

////////////////////////////////////////////////////////////////
// Simplex Noise utility code. Created by Reinder Nijhoff 2020
// https://turtletoy.net/turtle/6e4e06d42e
// Based on: http://webstaff.itn.liu.se/~stegu/simplexnoise/simplexnoise.pdf
////////////////////////////////////////////////////////////////
function SimplexNoise(seed = 1) {
const grad = [
[1, 1, 0], [-1, 1, 0], [1, -1, 0], [-1, -1, 0],
[1, 0, 1], [-1, 0, 1], [1, 0, -1], [-1, 0, -1],
[0, 1, 1], [0, -1, 1], [0, 1, -1], [0, -1, -1]
];
const perm = new Uint8Array(512);

const F2 = (Math.sqrt(3) - 1) / 2, F3 = 1 / 3;
const G2 = (3 - Math.sqrt(3)) / 6, G3 = 1 / 6;

const dot2 = (a, b) => a[0] * b[0] + a[1] * b[1];
const sub2 = (a, b) => [a[0] - b[0], a[1] - b[1]];
const dot3 = (a, b) => a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
const sub3 = (a, b) => [a[0] - b[0], a[1] - b[1], a[2] - b[2]];

class SimplexNoise {
constructor(seed = 1) {
for (let i = 0; i < 512; i++) {
perm[i] = i & 255;
}
for (let i = 0; i < 255; i++) {
const r = (seed = this.hash(i + seed)) % (256 - i) + i;
const swp = perm[i];
perm[i + 256] = perm[i] = perm[r];
perm[r + 256] = perm[r] = swp;
}
}
noise2D(p) {
const s = dot2(p, [F2, F2]);
const c = [Math.floor(p[0] + s), Math.floor(p[1] + s)];
const i = c[0] & 255, j = c[1] & 255;
const t = dot2(c, [G2, G2]);

const p0 = sub2(p, sub2(c, [t, t]));
const o = p0[0] > p0[1] ? [1, 0] : [0, 1];
const p1 = sub2(sub2(p0, o), [-G2, -G2]);
const p2 = sub2(p0, [1 - 2 * G2, 1 - 2 * G2]);

let n = Math.max(0, 0.5 - dot2(p0, p0)) ** 4 * dot2(grad[perm[i + perm[j]] % 12], p0);
n += Math.max(0, 0.5 - dot2(p1, p1)) ** 4 * dot2(grad[perm[i + o[0] + perm[j + o[1]]] % 12], p1);
n += Math.max(0, 0.5 - dot2(p2, p2)) ** 4 * dot2(grad[perm[i + 1 + perm[j + 1]] % 12], p2);

return 70 * n;
}
noise3D(p) {
const s = dot3(p, [F3, F3, F3]);
const c = [Math.floor(p[0] + s), Math.floor(p[1] + s), Math.floor(p[2] + s)];
const i = c[0] & 255, j = c[1] & 255, k = c[2] & 255;
const t = dot3(c, [G3, G3, G3]);

const p0 = sub3(p, sub3(c, [t, t, t]));
const [o0, o1] = p0[0] >= p0[1] ? p0[1] >= p0[2] ? [[1, 0, 0], [1, 1, 0]]
: p0[0] >= p0[2] ? [[1, 0, 0], [1, 0, 1]]
: [[0, 0, 1], [1, 0, 1]]
: p0[1] < p0[2] ? [[0, 0, 1], [0, 1, 1]]
: p0[0] < p0[2] ? [[0, 1, 0], [0, 1, 1]]
: [[0, 1, 0], [1, 1, 0]];
const p1 = sub3(sub3(p0, o0), [-G3, -G3, -G3]);
const p2 = sub3(sub3(p0, o1), [-2 * G3, -2 * G3, -2 * G3]);
const p3 = sub3(p0, [1 - 3 * G3, 1 - 3 * G3, 1 - 3 * G3]);

let n = Math.max(0, 0.6 - dot3(p0, p0)) ** 4 * dot3(grad[perm[i + perm[j + perm[k]]] % 12], p0);
n += Math.max(0, 0.6 - dot3(p1, p1)) ** 4 * dot3(grad[perm[i + o0[0] + perm[j + o0[1] + perm[k + o0[2]]]] % 12], p1);
n += Math.max(0, 0.6 - dot3(p2, p2)) ** 4 * dot3(grad[perm[i + o1[0] + perm[j + o1[1] + perm[k + o1[2]]]] % 12], p2);
n += Math.max(0, 0.6 - dot3(p3, p3)) ** 4 * dot3(grad[perm[i + 1 + perm[j + 1 + perm[k + 1]]] % 12], p3);

return 32 * n;
}
hash(i) {
i = 1103515245 * ((i >> 1) ^ i);
const h32 = 1103515245 * (i ^ (i >> 3));
return h32 ^ (h32 >> 16);
}
}
return new SimplexNoise(seed);
}
```