Get a form's fields in backend

I'm trying to build a plugin that unites our non-standard credit card processing company with our GForms registration forms. I need to find a way to get the field names for a given form so I can select which ones will be assigned to the CC processor's variables (Amount1 <=> field_1.2, for instance). I could probably whip up something using $wpdb, but I'd really rather work with the GForms API, if there's a way to do that.

Is there a simple function that I'm missing, that will allow me to do something like, say, this:

$form_fields = gf_get_fields( $form_id );
or even
$form = new GravityForm();

Thanks!

Yeah, that's what I ended up doing. I figured I knew how to get what I needed with $wpdb, and if it later turns out that there's a native GForms way to do it, I can always clean up my code after.

Thanks!