On Thu, 01 Sep 2016, Dan Dennedy wrote:

>    Jaromil asked me about this because we are preparing a new release, and we
>    decided to merge it into git master because the virtual function call only
>    occurs once per frame and is negligible.

yep, please note that is a *pure virtual* function: there is no
runtime resolution, hence no overhead.

I'll update the documentation accordingly

thanks!
ciao