T2d primitive?

I can't seem to find anything on it, but I seem to recall t2d supported primitives like lines, rectangles, etc.? The references don't seem to mention them, and I can't find anything in TDN. Anyone know if they exist and where I can find info on using them?

On use I see for primitives -- I have a level-select map, and when the cursor is hovered over a particular level's button (a planet) I want to pop up a sort of "word bubble" with a round-cornered rectangle containing the name of the level and a triangle pointing to the planet (which would be moving slowly). The easiest way I could think of was building primitives, since the rectangle will be arbitrarily sized and the triangle-section needs to be able to point to the button properly from any position.

I think I can get a satisfactory effect with sprites, but I'd rather use primitives if they're available.

Any suggestions on how to approach a word-bubble effect would be appreciated. Essentially, making a round-cornered rectangle of arbitrary dimensions.

Thanks!

-Jacob