Shape: Circle

The circle is generated, as most shapes are, on a square canvas to the maximum of either horizontal or vertical measurement up to the composite canvas size.

The circle is drawn as a circle, however for DVD, which has no "square" pixels in any of its resolution and aspect ratio combinations, "circles" actually are rendered as ellipses.
If you look closely at the composite you will notice that the circle is actually slightly shorter than it is wide. This is because the composite is made for a 720x480 4:3 DVD. When displayed from a DVD player it should be perfectly round.

Generating shapes in this manner allows us to change the line thickness proportionally over the entire shape, resulting in the same shape on the inside and outside edges (compare to GDI generated shapes with thick lines).