points.push_back (Offset (iv[LEFT], 0));
points.push_back (Offset (iv[RIGHT], 0));
points.push_back (Offset (iv.center (), protrude));
points.push_back (Offset (iv[LEFT], 0));
points.push_back (Offset (iv[RIGHT], 0));
points.push_back (Offset (iv.center (), protrude));