Re: [Adonthell-devel] backend handling

[Alexandre Courbot]

> Do you intend to "create" sdlgl backends for audio, input and main
> too? (I guess copying the existing sdl modules should suffice).
> Because the way the engine is written at present, it would be easier
> if the same backend was used for everything. Like the -b command line
> switch or the General/Backend config parameter are implemented to
> handle a single backend only.
>
> Or should we change stuff to allow different backends for the
> different engine parts? Like sdlgl for gfx, sdlal for audio and plain
> sdl for input and main. More tricky perhaps, but makes it easier to
> pick what's best for each part ...

I suppose the second solution would be better for us. Because it makes
sense to use SDL for graphics and (say) OpenAL for audio. Doing so
would not only allow us to mix backends elegantly, but it would also
having copies of the same directories everywhere (not exactly copies,
since class names must be changed) which would be hazardous to
maintain.

> If we stick to the first alternative, there's one more thing to think
> about: right now, "sdl" is hardcoded as default backend in
> adonthell::app::init. Would be nice if we'd figure out the best
> available backend at configure/cmake time and supply it as -DBACKEND
> or something like that.
>
> If we implement the second, we still might be able to do the same on a
> per engine part basis.

I think the right place for that is the configuration file. Or we
could give backends a "priority" number. Or maybe the app class could
select a "safe" backend (SDL makes sense here) by default if no better
backend is selected (that last solution sounds good to me, at least
for now - we just need to allow the user to switch backends through a
configuration menu).

Alex.