function circlePath(center, r) {
  var x = center.x,
      y = center.y;

  return [
    [ 'M', x, y ],
    [ 'm', 0, -r ],
    [ 'a', r, r, 0, 1, 1, 0, 2 * r ],
    [ 'a', r, r, 0, 1, 1, 0, -2 * r ],
    [ 'z' ]
  ];
}
@typedef {import('../util/Types').Point} Point

@typedef { {
  bendpoint?: boolean;
  index: number;
  point: Point;
} } Intersection