From: Filip Spacek <spacek@geocities.com>
  To  : ggi-develop@eskimo.com
  Date: Tue, 23 Feb 1999 22:13:44 -0500 (EST)

Re: libGGI3d -- ready to code?

On Tue, 23 Feb 1999 Daemonprince wrote:

> On Tue, Feb 23, 1999 at 08:23:45AM -0500, Filip Spacek wrote:
> > The way I see it is impossible to assign the same ids to two modules with 
> > the same interface without some sort of parser. For example if you have
> > two triangle drawers, you will get two _different_ ids. We will have to
> > have some sort of parser to recognise during compilation that the two
> > interfaces are indeed identical, or during pipeline construction to figure
> > out that those two ids represent the same type of interface. This parser
> > would do pretty much the same thing as a parser for non-COM proposal so
> > basically I don't see much advantages in using COM (except for runtime
> > shuffling in pipeline)
> > 
> Nah, thats the idea behind COM and CORBA and such like. The same interface
> has the same Id no matter where it is. When you need to find something to
> service you, you just ask what has Interface X. There is no need to identify
> which module is which because they are seperate files.
> 
> I think a COM like interface would work like an extended ELF interface from
> what little I know about ELF. Request Interface Id X get served a possible
> list of modules. Select fastest one. This goes on down the pipe and this
> way we are profiled and pipe is built. Smart modules which do things
> like threading can be stuck into this pipe to send stuff down alternate pipes.
> 
> The thing I can see definately being needed is an atomic write to both the
> Z and pixel buffers. Though this may be acheived by having all branches
> rejoin at final level.

I don't think I understand you here. By asking for Interface X do you mean
asking for a module with a certain COM id? If that is true how do you
know the id to begin with? Standards? (no-no)

If by asking for Interface X you mean asking for a module with certain
type of interface, then you have to have a way of specifing the interface
(such as the structure I described in earlier email) and in that case what
do you need the id for?  

Another thing is that we cannot classify the modules using only the
interface (can we?) it is perfectly possible to have two different types
of modules with the same interface (same type of data being passed)

-Filip

p.s.: I think I'm missing something obvious here. Thanks for the patience.