Exposing cairo based implementation of CSS as an API in GTK+/gtkmm

[Samik Ganguly <sganguly87 gmail com>]

Hello Gtk+ developers,
    Gtk+ implements various CSS3 functionality so that widgets can be 
styled with CSS. As far as I understand these effects are implemented 
with cairo drawing API. Is there any chance to expose some of the 
effects such as blurred shadow, transitions etc. as generic functions in 
Gtk+ API so that they can be used without CSS?
For example, if someone is doing some custom drawing with cairo on Gtk+ 
such as non rectangular widgets, curves with shadow etc. then they can 
take advantages of such API instead having to implement those effects 
with cairo themselves. For rectangular widgets StyleProvider's 
draw_background, draw_frame methods can be used to specify such effects 
in CSS, but for others I'm guessing they're probably not suitable.
Libraries such as clutter expose similar kind of effects in its API but 
since Gtk+ uses cairo it'd be easier to add those effects to custom 
drawings based on cairo. I'm curious to know if developers have plans 
for such API.
Thanks.
Samik Ganguly