Re: Scripts vs APIs

rayn@crossaccess.com
Thu, 8 Sep 1994 11:18:06 -0700


John.Ellson@att.com:
> For example, in tsipp (a tcl extension) I can write:

> set metal_dull [SippShaderStrauss 0.4 0.2 0.9 {0.6 0.33 0.27}]
> set cornerBlock [SippBlock {.5 .5 5} $metal_dull WORLD]
> SippObjectMove $cornerBlock {-3.75 -2.25 0}
> set cornerBlock [SippObjectInstance $cornerBlock]
> SippObjectMove $cornerBlock {3.75 -2.25 0}

> which uses variables and procedures to describe two dull-metal blocks.
> How can I do this efficiently without them?

This seems to be merely declaring the values of metal_dull,
cornerBlock, and the location of cornerBlock. Is cornerBlock moving in
this example? that would be the only thing not possible (as I
understand it) with a purely declarative language. Well, not possible
is perhaps not true. That is the scripting vs API thread really, as an
attribute of the object can be declared which defines the behavior of
the object. This does not necessarily require the VRML language to be
anything more than descriptive.

So, in setting a variable, you are actually just declaring the
attributes of an object. If you wish dynamic action, then there is
indeed a problem. (but from my understanding, VRML is intended to be
static, like HTML)