[net.micro.mac] Star Demo posted, LightSpeed C is great!

oster@ucblapis.berkeley.edu (David Phillip Oster) (06/14/86)

I translated Mr. Hawley's demo  (thanks!) into LightSpeed C, made it a
desk accessory, and added some bells and whistles of my own. The
translation was no problem - the compiler gave two error messages about
obvious, non-portable constructs. The source code for the new version is
posted to net.sources.mac .

I've sped it up (LightSpeed's profiler said that almost all the time wsa
being spent inside LineTo, so I took LineTo out.)  I added 4 different
kinds of stars, that are drawn with Copybits. (The smaller ones have the
copybits calls optimized into FlipPixel.)  You'll find some interesting
routines in the code, even if you aren't interested in a Star Trek-like
stars effect.

Xerox lisp machines have a similar screen hack, but their version has
black holes, novas, spiral galaxies, and planets.  If anyone would like to
extend my version and repost it to the net, feel free. (You should add
comets, Mr. Hawley.)

I posted an earlier note about bugs in desk accessories written in
LightSpeed C.  You do have to be careful if you override a tool trap with
a C procedure, and that procedure references global variables.  But aside
from that, the system works just the way it should, and is a joy to use.

The "about" choice in LightSpeed C is yet another version of this screen
hack.

--- David Phillip Oster		-- "The goal of Computer Science is to
Arpa: oster@lapis.berkeley.edu  -- build something that will last at
Uucp: ucbvax!ucblapis!oster     -- least until we've finished building it."