Canvas.setpenopacity(-1)

const turtle = new Turtle();

const steps = 34;      // min=5 max=40 step=1 helix elements
const helixWidth = 37; // min=5 max=80 step=1 helix width
const shapeW = 24;     // min=2 max=30 step=1 structure width
const shapeH = 11;      // min=1 max=15 step=1 structure height
const turns = 1;       // min=1 max=6 step=1 structure peaks

const cos = a => Math.cos(a * Math.PI / 180);
const sin = a => Math.sin(a * Math.PI / 180);

function drawEllipse(cx, cy, w, h, rot){
  const segments = 36;
  turtle.jump(
    cx + cos(rot) * w,
    cy + sin(rot) * h
  );
  for (let i = 1; i <= segments; i++){
    const a = rot + (i / segments) * 360;
    const px = cx + cos(a) * w * cos(rot) - sin(a) * h * sin(rot);
    const py = cy + cos(a) * w * sin(rot) + sin(a) * h * cos(rot);
    turtle.goto(px, py);
  }
}

function drawLine(cx, cy, w, rot){
  turtle.jump(cx + cos(rot) * w, cy + sin(rot) * w);
  turtle.goto(cx - cos(rot) * w, cy - sin(rot) * w);
}

const totalAngle = turns * 360;

for (let i = 0; i < steps; i++){
  const t = i / (steps - 1);

  const y = -90 + t * 180;                    // vertically distributed
  const rot = t * totalAngle;
  const x = cos(rot) * helixWidth;            // horizontally distributed

  drawEllipse(x, y, shapeW, shapeH, rot);
  drawLine(x, y, shapeW * 0.6, rot + 90);
}