Re: [newbie] Question on embedding/extending with boost::python

Brett Calcott wrote:
> "Dirk Gerrits" <dirk@xxxxxxxxxxxxxxxxxx> wrote:
>
> > Chris Heald wrote:
>
[snip]
> I had previously embedded python in my c++ app so that I could script my
> agents, but the result was very slow as this effectively did this
> (vastly simplified)
>
> while (engine_running)
> {
>     for (agents_container:iterator a = agents.begin(); a !=
>         agents.end(); ++a)
>     {
>         // here we call out to python for each agent
>         (*a).update_yourself_via_python()
>         update_visual_stuff()
>     }
> }
>
> The calls to python are in the inner loop and this is slow.

Well I suppose you could expose a visual_stuff_updating_iterator to 
Python, but extending is of course a much easier and cleaner.

> What I am doing now is different - I am constructng an engine in C++,
> making all the agents and world parameters accessible to python, BUT
> the update main loop remains entirely in C++:
>
> import engine # boost python module
>
> while engine_running:
>     engine.cycle()

I'm not sure I follow. Is engine.cycle() still doing a 
a->update_yourself_via_python() for every agent? Then where's the 
speedup compared to the embedded approach?

Regards,
Dirk Gerrits