[cairo] Does cairo respect the alpha component of a color ?

[Ravindra Kumar]

[This is a resend as I did not see my first mail.
I'm sorry, if you got it twice.]

Hi folks,
I had a simple question about the way cairo
deals with the alpha component. So far, I
have seen that cairo does not care about
alpha values lying in between 0 and 1. It just
behaves as alpha on/off. Is it the intended
behavior or I have hit some bug ?

Regards,
- Ravindra