Re: [freesci-develop] Glutton OS X sound support & wrapper for FreeSCI, was: Concerning C416: No sound on Mac OS X

[Christoph Reichenbach]

Hi,

> >I like SDL, was  there any other similar multi-platform graphic module 
> >considered for Glutton or is SDL kinda seen as a standard?
> >It would be nice to get SDL working again for Glutton if its still 
> >being considered, I doubt Glutton will give any output right now for 
> >OS X.
> 
> Just a month or two ago I got glutton running on OS X, sans sound (if I 
> remember correctly it wasn't too difficult). Not sure how it is now.
> 
> The funny thing is that this project has support for many libraries, 
> such as directfb and libggi. Personally I don't see the purpose of 
> having any other  library than SDL, as it is by far the most mature and 
> supported cross platform multimedia library I know of.

FreeSCI's SDL graphics driver is the slowest graphics driver we
have at the moment, and I'm not convinced that our implementation
is to be blamed (although I'd be more than happy to see an improvement
here); if I recall correctly, it is mostly that our rendering model
does not map to SDL's conception of what a rendering model should be
like. Again, I may be wrong, I'd be happy to be told otherwise.
  So far, FreeSCI has managed to avoid any dependencies on non-system
libraries at least on the UNIX side (on the non-UNIX side, our general
infrastructure would make it possible not to depend on glue libraries
such as libSDL-- and there has been some work on getting this to work
for Win32, if I recall correctly-- but UNIXish systems are the only
ones that don't need SDL at the moment). As we already have all of the
relevant infrastructure in place, I don't see any point in dropping
support for non-SDL libraries.

  Of course, SDL is much more popular and stable these days than it
was when we started working on FreeSCI. It still doesn't seem to have
any support for sound other than PCM, but it is definitely the most
worthwhile target for an initial implementation of a PCM driver.

> I don't know 
> much about directfb, but I think using OpenGL through SDL would be a 
> more portable option for hardware accelerated graphics.

That definitely sounds like a worthwhile new graphics driver. I'm
not sure how much we would have to change in the operational gfx layer
to support the kinds of fullscreen redraws that would work best with
OpenGL, but I do recall that some thought went into supporting this.

Having an OpenGL driver would allow us to take advantage of the
following hardware-accellerated features:
 - Pixmap scaling
 - Z buffer (or stencil buffer) in hardware
There's currently no hook for choosing filtering methods in gfx
drivers, but it may be worthwhile to add those.

[...]
> Seriously, I'm swamped with work so if you want to release a simple 
> version please don't let me hold you back. The demo idea is fantastic 
> (and they're small). When I have free time this winter we could 
> definitely work together on a nice glutton build (assuming glutton is 
> far enough around then).

I will try to see whether I can fix the Glutton PCM sound infrastructure
during fall break so that you guys can work with that. Of course,
Glutton is nowhere as stable as the main branch, doesn't have savegames
etc., so a public release for non-glutton would be better.

> I personally was thinking of creating a real 
> preferences file in ~/Library/Preferences, creating a good icon,

We already have one (a png file), but it's a little lower in resolution
than most OS X icons are.

> adding 
> open dialogs, and maybe adding a preference windows. Just recently it's 
> become easy to make SDL applications even more OS X like, so there may 
> be some more possibilities.

Note that recent work on a game selection screen indicates that we may
actually have a built-in mechanism for setting preferences soon, however:
 a) This hasn't been implemented yet
 b) It won't look like OS X
Still, as there's some considerable potential overlap here, you should
be aware of this-- it may be worth to co-ordinate efforts to build a
common configuration infrastructure which both approaches would merely
be frontends to.

> >Also, would the performance for the adlibemu be better with (real) 
> >sound cards instead if the basic Apple soundcards? The only card I 
> >find that has OS X support is the Revolution 7.1 but it does not have 
> >midi channels.
> >I was hoping to get real midi through my soundblaster live but it 
> >seems Creative dropped OS X support. Searching over the internet it 
> >looks like the soundblaster cards are the only sound cards left with 
> >midi channel support.

What kinds of performance issues are you having? Note that there are
two well-known problems in 0.3.x which may be related to this:
 (a) Sound timing is generally quite a bit off-- we don't play notes
in advance; as such, timing is off if the sound server process/thread
is not scheduled to be run at precisely the point in time it requests
to be run. (Yes, this is stupid, and it's why we got rid of the entire
sound subsystem in its current form for glutton).
 (b) The SDL graphics driver (in its current implementation) is quite
slow, i.e. you might be blaming the wrong subsystem here.


-- Christoph