[openvrml-develop] Making Lookat useful

[Braden M. <br...@en...>]

It'll be some weeks before I start any development on this; but the
ideas are bouncing around in my head, so I thought I'd go ahead and post
them to get a reaction...

The major item I'll be pursuing for the 0.13 release is a good
asynchronous I/O story. My plan for this is to use C++ standard
iostreams in conjunction with threads (probably Boost threads). As part
of this change, network code will be removed from the library. There
will be a virtual stream factory method, probably on a Browser class,
that users of the library will need to implement.

The downside of this is that OpenVRML will become more difficult to use;
the upside is that OpenVRML will be able to leverage whatever network
code is in place in the host environment. So if one were writing a
browser plug-in, one could use the network functionality exposed by the
browser's API, and presumably leverage things like the browser's cache.

Because the approach to implementing the streams is not readily apparent
to persons unfamiliar with the iostreams framework, and more importantly
because we will need a means of testing the "upstream" code in OpenVRML,
a sample implementation will be provided. So Lookat will be improved
along this vector, both to provide that implementation and to keep
Lookat functioning alongside the library.

And at that point we have a choice: What network code do we use as the
basis for the sample implementation? The code must remain
cross-platform, and any dependencies should be widely deployed (or at
least readily available).

One obvious candidate is the W3C's libwww. This, I imagine, would be
very good for illustrative purposes, but little else. I get the
impression that there isn't a whole lot of nontrivial code that depends
on libwww. And presumably there are good reasons for that. Still, if
providing an illustration is what is called for--and that is Lookat's
primary purpose--I am sure it would fit the bill.

But there is another alternative: turn Lookat into a Mozilla plug-in. In
this case we would, of course, use Mozilla's networking facilities. The
disadvantage? Lookat would nolonger be a standalone viewer. I get the
impression that a lot of folks like having a standalone viewer, but
frankly it's lost on me. The advantage is that, IMO, a Mozilla plug-in
would be much, much more useful than what Lookat is now.

So I'd like to take the group's temperature on this. A Mozilla plug-in
is definitely a more ambitious project; but I'd like to maximize the
value of the development time I spend on OpenVRML, and I think it's the
way to go in that respect.

-- 
Braden McDaniel                           e-mail: <br...@en...>
<http://endoframe.com>                    Jabber: <br...@ja...>