 } else if (moveNdx === 3) {
        points[2] = v2.add(points[2], delta);
        points[4] = v2.add(points[4], delta);
      }

      render();
    }
  }

  document.querySelector("#lock").addEventListener('change', (e) => {
    locked = e.target.checked;
  });

  window.addEventListener('resize', render);

  function drawDot(ctx, x, y, radius, outline) {
    ctx.globalAlpha = outline ? 0.2 : 0.5;
    ctx.beginPath();
    ctx.arc(x, y, radius, 0, Math.PI * 2, false);
    ctx.fill();
    ctx.globalAlpha = 