universes in S-Dynamics

["Craig W. Reynolds" <cwr%white.sww.symbolics.com@RELAY.CS.NET>]

    Date: Fri, 19 May 89 13:39 PDT
    From: Jennifer J. Hiscox <JHiscox@WHITE.SWW.Symbolics.COM>

(Thanks for forwarding this to me.)

    Date: Wed, 17 May 89 07:35 PDT
    From: J. Penberthy <JSP@ibm.com>
    To: slug@Warbucks.AI.SRI.COM

    Has anyone used the "universe" construct in S-Dynamics for anything
    besides S-Geometry?  I'm interested in using the S-Dynamics sequence
    editor for controlling and monitoring experiments with other software.

Yes.  Marc Scaparro (formally an employee of Longwood Video in New York
City (which uses the S-Products) and now freelance consultant) has
defined a couple of universes, although they are both closely related to
DynaGeometry.  Marc has been using the experimental "New Mode" and
wanted to create an S-Dynamics interface to my Boids system and his
Waves system.  "New Mode" is present in the SGD 4.1 release but turned
off by default.  Primarily it provides substrate for seamlessly adding
new "dynamic operations" (previously known as "motion types") to the set
supported by S-Dynamics, such that the normal user interface "knows
about" the new operations.  But you should take this all with a grain of
salt, the reason "New Mode" is not turned on by default was that it was
still under development at the time of the release freeze.

    Any hints would be appreciated.

I could give more specific hints if you had more specific questions.  It
might be that all you need to do is to turn on the DynaLisp universe and
turn off DynaGeometry and DynaRender.  Then Dyna just becomes a system
for "scripting" the evaluation of Lisp forms over time.

    Cheers,
    Scott

    P.S. What's SI:DEF-DEFINING-FORM?  Can't find it in 7.2, but it's all
    over the S-dynamics source.

It was used first in Joshua, and then later in S-Dynamics.  The fact
that it is named in the SI package is essentially wishful thinking:
"gee, wouldn't it be swell if this was installed in Genera?"  For now,
the function lives in #P"SYS:COLOR;SUPPORT;DEF-DEFINING-FORM" which is
supposed to be part of the "Graphics Support" system, a component of
S-Dynamics.  If you did not get that file with the rest of your sources,
let us know.

The basic idea, if it wasn't clear, was to have one centralized way of
defining a macro for making top level definitions in the source
(analogues of DEFUN, like DEFUNIVERSE) that takes care of the eight
kinds of declarations commonly associated with such a definer.